DOI: 10.3897/jucs.152399

Authors: Abdelhady Naguib, Abdulaziz Shehab

Abstract: The importance of localization algorithms is due to their uses in various wireless sensor network applications. A single anchor movement can be used to aid in localization to reduce the cost of using multiple anchors or equipping sensor nodes with GPS units, but the main challenge here is choosing the best path of movement while avoiding potential obstacles. This paper proposes a path planning algorithm called Square Spiral with Obstacle Avoidance (SQSPOA) which allows a mobile anchor node to track an optimal path while broadcasting its current coordinates to the unknown sensor nodes. During its movement, the mobile anchor node faces many obstacles that may hinder its mobility; but as a result of the superiority of the proposed algorithm the mobile anchor can avoid these obstacles while still broadcasting its coordinates to sensor nodes. The performance of the proposed algorithm was evaluated at the presence of variable-sized obstacles and was compared with recent path planning algorithms. Simulation results proved the superiority of the proposed algorithm with respect to localization error, percent of localized sensor node and trajectory length.

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DOI: 10.3897/jucs.140463

Authors: Daniel Spiekermann

Abstract: The evolution of modern data centers from traditional hardware-based infrastructures to highly virtualized environments has introduced new complexities in network traffic analysis. Virtual networks, characterized by dynamic changes in both overlay and underlay architectures, necessitate sophisticated methods for accurate anomaly detection and network analysis. This paper investigates the real-world behaviour of network traffic within virtualized environments, identifying the key factors that impact packet dynamics, including VM operations, multi-tenancy, user customization, and hardware adjustments. By defining the frequency and nature of these events, this research provides further details for the creation of accurate packet generation tools. These tools must simulate the dynamic characteristics of virtual networks, enabling reliable and realistic synthetic data generation. The research explains the need for enhanced packet generation methodologies to provide valid training and testing data for digital investigations, anomaly detection, and network simulations. As a result, this paper emphasizes the importance of developing accurate synthetic network traffic that mirrors real-world conditions and provides a valid basement for traffic analysis in virtual networks.

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DOI: 10.3897/jucs.167412

Authors: Yanling Chen

Abstract: In this paper, we show the problem of two-party privacy-preserving record linkage (PPRL) can be seen as an identification problem in Information Theory. We propose to apply the identification codes that are designed for identification via channels to the problem of PPRL, due to their advantage in the performance analysis, especially on a quantitative evaluation of the privacy. Note that for the PPRL, linkage quality is typically evaluated experimentally, whilst for privacy, there are so far no commonly accepted privacy measures available that allow an objective evaluation. Our approach of identification code provides an objective evaluation on both linkage quality and privacy based on parameters of employed identification codes.

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DOI: 10.3897/jucs.164654

Authors: Wolfram Luther, A. J. Han Vinck

Abstract: This volume presents a conference paper selection from the 4th Workshop on Collaborative Technologies and Data Science in Smart City Applications (CODASSCA 2024): Data Science and Reliable Machine Learning, held in Yerevan, Armenia, October 3-6, 2024, https://codassca2024.aua.am/. The special issues guest editors invited five groups of authors from Armenia, Chile, Germany, the UK, and the USA to submit enlarged versions of their CODASSCA 2024 papers There was also a J.UCS open call so that any author could submit papers on the highlighted subjects. The invitation to review the 16 contributions received was accepted by 16 experts, and, after three rounds, seven articles were finally accepted for publication in the special issue.

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DOI: 10.3897/jucs.97822

Authors: Herminia Beatriz Parra de Gallo, Marcela Vegetti

Abstract: This paper shows the research conducted to respond to a continuous requirement of justice regarding the application of scientifically supported forensic tools. Considering ontological engineering as the appropriate framework to respond to this requirement, the article presents OntoFoCE (Spanish abbreviation for Ontology for Electronic Mail Forensics), a specific ontology for the forensic analysis of emails. The purpose of this ontology is to help the computer expert in the validation of an email presented as judicial evidence. OntoFoCE is the fundamental component of the ObE Forensics (Ontology-based Email Forensics) tool. Although there are numerous forensic tools to analyze emails, the originality of the one proposed here lies in the implementation of semantic technologies to represent the traceability of the email transmission process. From that point on, it is possible to provide answers to the items of digital evidence subject to the expert examination. These answers make it possible to support these evidence items in the forensic analysis of an email and to guarantee the gathering of scientifically and technically accepted results that are valid for justice. Thus, the research question that is tried to be answered is: Is it possible to apply ontological engineering as a scientific support to design and develop a forensic tool that allows automatic answers to the evidence items subject to the expert examination in the forensic analysis of emails?

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DOI: 10.3897/jucs.66714

Authors: Andrea Lezcano Airaldi, Jorge Andres Diaz-Pace, Emanuel Irrazábal

Abstract: Data-driven storytelling helps to communicate facts, easing comprehension and decision making, particularly in crisis settings such as the current COVID-19 pandemic. Several studies have reported on general practices and guidelines to follow in order to create effective narrative visualizations. However, research regarding the benefits of implementing those practices and guidelines in software development is limited. In this article, we present a case study that explores the benefits of including data visualization best practices in the development of a software system for the current health crisis. We performed a quantitative and qualitative analysis of sixteen graphs required by the system to monitor patients' isolation and circulation permits in quarantine due to the COVID-19 pandemic. The results showed that the use of storytelling techniques in data visualization contributed to an improved decision-making process in terms of increasing information comprehension and memorability by the system stakeholders.

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DOI: 10.3897/jucs.74166

Authors: Armando Cruz, Hugo Paredes, Leonel Morgado, Paulo Martins

Abstract: Virtual worlds, particularly those able to provide a three-dimensional physical space, have features that make them suitable to support collaborative activities. These features distinguish virtual worlds from other collaboration tools, but current taxonomies of the field of Computer-Supported Cooperative Work do not account for several distinctive features of virtual worlds, namely those related with non-verbal communication. We intended to find out how the use of an avatar, gestures, spatial sounds, etc., influence collaboration in order to be able to include non-verbal communication in taxonomies of the field Computer-Supported Cooperative Work. Several cases of collaboration in virtual worlds are analysed, to find the impact of these non-verbal characteristics of virtual worlds. We proposed adding the concept of Presence to taxonomies of Computer-Supported Cooperative Work and contribute with guidance for future taxonomy development that includes it as a new dimension. This new dimension of Presence is subdivided into "avatar" and "physical space" subdimensions. In turn, these are divided into "physical appearance", "gestures, sounds and animations" and "focus, nimbus and aura"; "environment" and "objects / artefacts". This new taxonomy-development proposal may contribute to inform better design of virtual worlds in support of cooperative work.

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DOI: 10.3897/jucs.67046

Authors: Marcelo Aires Vieira, Elivaldo Lozer Fracalossi Ribeiro, Daniela Barreiro Claro, Babacar Mane

Abstract: With the growth of cloud services, many companies have begun to persist and make their data available through services such as Data as a Service (DaaS) and Database as a Service (DBaaS). The DaaS model provides on-demand data through an Application Programming Inter- face (API), while DBaaS model provides on-demand database management systems. Different data sources require efforts to integrate data from different models. These model types include unstructured, semi-structured, and structured data. Heterogeneity from DaaS and DBaaS makes it challenging to integrate data from different services. In response to this problem, we developed the Data Join (DJ) method to integrate heterogeneous DaaS and DBaaS sources. DJ was described through canonical models and incorporated into a middleware as a proof-of-concept. A test case and three experiments were performed to validate our DJ method: the first experiment tackles data from DaaS and DBaaS in isolation; the second experiment associates data from different DaaS and DBaaS through one join clause; and the third experiment integrates data from three sources (one DaaS and two DBaaS) based on different data type (relational, NoSQL, and NewSQL) through two join clauses. Our experiments evaluated the viability, functionality, integration, and performance of the DJ method. Results demonstrate that DJ method outperforms most of the related work on selecting and integrating data in a cloud environment.

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DOI: 10.3217/jucs-025-09-1199

Authors: François Bouchaud, Gilles Grimaud, Thomas Vantroys, Pierrick Buret

Abstract: The Internet of Things (IoT) is everywhere around us. Smart communicating objects are offering the digitalization of lives. They create new opportunities within criminal investigations. In recent years, the scientific community sought to develop a common digital framework and methodology adapted to IoT-based infrastructure. However, the difficulty in exploiting the IoT lies in the heterogeneous nature of the devices, the lack of standards and the complex architecture. Although digital forensics are considered and adopted in IoT investigations, this work only focuses on the collection. The identification phase is quite unexplored. It addresses the challenges of locating hidden devices and finding the best evidence to be collected. The matter of facts is the traditional method of digital forensics does not fully fit the IoT environment. Furthermore, the investigator can no longer consider a connected object as a single device, but as an interconnected whole one, anchored in a cross-disciplinary environment. This paper presents the methodology for identifying and classifying connected objects in search of the best evidence to be collected. It offers techniques for detecting and locating the appropriate equipment. Based on frequency mapping and interactions, it transfers the concept of "fingerprinting" into the field of crime scene. It focuses on the technical and data criteria to successfully select the relevant IoT devices. It gives a general classiffication as well as the limits of such an approach. It shows the collection of digital evidence by focusing on pertinent information from the Internet of Things.

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DOI: 10.3217/jucs-025-07-0740

Authors: Sonia Estévez, M. Cambronero, Yolanda García-Ruiz, Luis Llana Díaz

Abstract: Parkinson's disease (PD) is the most common age-related neurodegenerative motor disease. People with Parkinson's have different motor symptoms related to movement, the most common of which are tremor, muscle rigidity and slowness of movement. In addition, there are other problems that are unrelated to motor symptoms, such as sleep behavior disorders, personality changes, pain and depression. Numerous apps designed for people with this disease have been developed in recent years. Due to the diversity of symptoms, there are very many different apps. Our goal is to carry out a systematic review of available apps related to PD for the operating systems iOS and Android and to assess their features. In addition, we are interested in the United States of Americability of the apps. A search for the representative terms "Parkinson" and "Parkinson's Disease", together with the descriptors of the symptoms, was conducted in the Google Play and Apple App stores. Next, we screened the PD-related apps. Finally, we assessed the apps with respect to symptoms, users, purpose and features. In addition, a United States of Americability evaluation was carried out.

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DOI: 10.3217/jucs-024-09-1170

Authors: Chi-Yi Lin, Kai-Hung Liao, Chia-Hsuan Chang

Abstract: With the rapid development of Internet of Things (IoT), it is an inevitable trend that all things will get connected to the Internet to form various intelligent services such as Industry 4.0, smart home, smart medical care, etc. To make such intelligent IoT services practicable, it is vital to have a low-power link-layer technology that can accommodate a diversity of upper-layer networking protocols. Currently, there are many popular low-power wireless networking technologies for IoT such as ZigBee and Bluetooth Low Energy (BLE). Because of the ubiquity of BLE-enabled smartphones nowadays, BLE has gained much attention in the IoT industry recently. In this research, we aim at implementing an IPv6 over BLE experimental system using Raspberry Pi 3 and nRF51-DK development boards, and then run the Message Queuing Telemetry Transport for Sensor Networks (MQTT-SN) protocol and the Constrained Application Protocol (CoAP) over the protocol stack of IPv6/BLE. Specifically, in our experimental system every BLE node is IPv6-addressable and accessible through the MQTT/CoAP protocols from anywhere over the Internet. Moreover, to ease user accesses from ordinary web browsers, we build two gateways as the web servers for end users, which receive real-time sensor data via CoAP or MQTT-SN protocols and then push the data to end users' browsers. The gateways are also designed to routinely request sensor data and then forward the data to cloud database platforms, which serve as the data sources for historical sensor data. Preliminary results showed that our system is capable of achieving the designed goals and is user-friendly. Compared with the non-IP based BLE sensor networks, our implementation can be integrated into a variety of existing and widely used IP-based applications easily.

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DOI: 10.3217/jucs-024-05-0634

Authors: Simon Vrhovec, Blaž Markelj

Abstract: Critical infrastructure is a high value target in the real world and cyberspace. A failure to protect the critical infrastructure in the cyberspace could lead to serious financial and material losses and violate the effective functioning of a country. In this paper, we will focus on healthcare as an important part of the critical infrastructure. An important part of the healthcare infrastructure are hospitals. Hospital personnel is increasingly using mobile devices in their everyday work to improve patient care. Hospitals may however fail to adequately address the use of mobile devices and adapt their information security policies in time. Hospital personnel may use both their personal and work mobile devices for everyday work. Sometimes they do it without adhering to an adequate hospital information security policy. The objective of this paper is to study the relation between the use of mobile devices, adhering to hospital information security policy and perceived consequences of data breaches. An exploratory survey (N = 95) has been conducted in a Slovenian hospital. Respondents were asked about the use of their personal and work mobile devices for accessing medical data, adhering to the hospital information security policy, and the perceived consequences of data breaches for themselves, the hospital and the patients. The results show that perceived personal consequences are negatively correlated with personal and work mobile device use for work. Also, adhering to information security policy is positively correlated with perceived data breach consequences for both the patients and the hospital.

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DOI: 10.3217/jucs-023-10-0969

Authors: Alexandros Fakis, Georgios Karopoulos, Georgios Kambourakis

Abstract: While more and more users turn to IP-based communication technologies, privacy and anonymity remain largely open issues. One of the most prominent VoIP protocols for multimedia session management is SIP which, despite its popularity, suffers from security and privacy aws. As SIP messages are sent in plain text, user data are exposed to intermediate proxies and eavesdroppers. As a result, information about users participating in a call can leak from header data, which cannot be omitted since they are needed for the correct routing of SIP messages to their final destination. Even more, traffic analysis attacks can be mounted with data stemming from lower layers. To redress this kind of problems, privacy can be achieved either by the construction of a lower level tunnel (via the use of SSL or IPsec protocols) or by employing a customtailored solution. However, SSL and IPsec are known for leading to undesirable, non affordable delays, and thus the need for a SIP-oriented solution is preferable. In the context of this article, we evaluate three alternative solutions to encounter the above issues. More specifically, we use two well-known anonymity networks, Tor and I2P, for secluding both caller's and callee's actions by securing SIP messages content. As a third solution, we present our proposal for preserving privacy in SIP signaling, by using an onion-routing approach, where selected sensitive fields of SIP messages are encrypted using either asymmetric or symmetric encryption. We compare these three alternatives in terms of performance, mentioning the pros and cons that come up with each proposal. Our work also presents the reasons why other existing anonymity networks fail to be considered as appropriate for preserving anonymity in SIP.

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DOI: 10.3217/jucs-023-09-0932

Authors: Rebekka Alm

Abstract: Increasingly exible production processes require intelligent assistance systems containing information and knowledge to maintain high quality and efficiency. To ensure a reliable supply of information, it is of great importance to find easy and fast ways to record and store "new" information, as well as to provide a sensible mechanism to supply the information when needed. In this paper an approach is presented that uses annotations in combination with a formalized knowledge base that represents the work domain. This pre-condition enables a context-based annotation recommendation. A framework is proposed to integrate different factors to measure the relevance of an annotation according to a given situation. The approach is illustrated using the example of an assembly assistance system. To evaluate the users' attitude regarding annotations as instruction support and to test the system's capabilities when handling a great number of annotations some studies were performed and analyzed.

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DOI: 10.3217/jucs-023-08-0755

Authors: Akrivi Krouska, Christos Troussas, Maria Virvou

Abstract: Twitter is a highly popular social networking service and a web-based communication platform with million users exchanging daily public messages, namely tweets, expressing their opinion and feelings towards various issues. Twitter represents one of the largest and most dynamic datasets for data mining and sentiment analysis. Therefore, Twitter Sentiment Analysis constitutes a prominent and an active research area with significant applications in industry and academia. The purpose of this paper is to provide a guideline for the decision of optimal algorithms for sentiment analysis services. In this context, five well-known learning-based classifiers (Naive Bayes, Support Vector Machine, k-Nearest Neighbor, Logistic Regression and C4.5) and a lexicon-based approach (SentiStrength) have been evaluated based on confusion matrices, using three different datasets (OMD, HCR and STS-Gold) and two test models (percentage split and cross validation). The results demonstrate the superiority of Naive Bayes and Support Vector Machine regardless of datasets and test methods.

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DOI: 10.3217/jucs-023-03-0327

Authors: Mahmoud Al-Ayyoub, Huda Al-Sarhan, Majd Ud, Mohammad Al-Smadi, Yaser Jararweh

Abstract: This paper aims at fostering the domain of Arabic affective news analysis through providing: (a) a benchmark annotated Arabic dataset of news for affective news analysis, (b) an aspect-based sentiment analysis (ABSA) approach for evaluating the sentimental affect of Arabic news posts on the reader, and (c) a baseline approach with a common evaluation framework to compare future research results with the baseline ones.

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DOI: 10.3217/jucs-023-03-0256

Authors: Ahmet Güneyli, Metin Ersoy, Şevki Kıralp

Abstract: In this research, a case study was conducted, analyzing the Twitter messages posted between July and November 2015 by six political leaders in Turkey. The Twitter messages posted by President Erdoğan, AKP's leader Davutoğlu, CHP's leader Kiliçdaroğlu, MHP's leader Bahçeli and HDP's co-chairs Demirtaş and Yüsekdağ were all examined. The analysis focused primarily on the messages that were related to terrorism. The research utilized a descriptive and qualitative approach as well as thematic content analysis. To consolidate the thematic content analysis, numerical data (total word amount and arithmetic mean), charts and tables were used. During the relevant period, terrorism and political instability dominated Turkish politics, and, on 1 November 2015, early elections were held. This research concluded that the six leaders differed in their approaches towards terrorism, which constituted a key issue for the political leaders in Turkey by dominating the political discourse during the electoral campaign.

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DOI: 10.3217/jucs-022-08-1072

Authors: Hiroaki Fukuda, Paul Leger, Keita Namiki

Abstract: A Wireless Sensor Network (WSN) is typically deployed in a location in which no electrical source is provided, meaning that sufficient battery life is crucial. Applications for WSNs require implementations of complex operations such as network administration. To simplify the development of these applications, several mobile agent middleware solutions have been proposed. Applications for these middleware frameworks are executed by communication among agents; therefore, a common operation is to look up agents. Because existing proposals do not have much technical support for an efficient approach to look up agents, every lookup consumes a significant amount of battery power and time. In addition, current approaches can fail in their lookup operations if the target agent moves during a lookup operation. This paper proposes Chord for Mobile agent on Sensor Network (CMSN), an efficient and effective lookup for mobile agent middleware. CMSN is inspired by Chord for Sensor Networks (CSN), which introduces hierarchical ring structures and a distributed hash table algorithm to improve lookup performance. Unfortunately, CSN cannot be applied to mobile agent middleware solutions because CSN always requires a base station and assumes no agent migration between nodes. Unlikely CSN, CMSN is designed for an environment where agents can freely move between nodes without dependency on a special node such as a base station. In addition, CMSN leverages a feature where the location of a node is stationary in order to improve lookup performance with simplified algorithms. We evaluate and compare CMSN in terms of performance, effective lookups, and battery consumption.

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DOI: 10.3217/jucs-022-05-0630

Authors: Mohammad Al-Smadi, Mahmoud Al-Ayyoub, Huda Al-Sarhan, Yaser Jararweh

Abstract: Great challenges arise due to the rapid growth of online data. The widespread use of online social networks (OSN) have enabled the generation of massive amounts of raw data where users post their own material. One interesting example of user generated data is their political views and opinions. The ability to crawl OSN and automatically analyze their political content is of undeniable importance. However, this requires automated methods for posts’ tone analysis, sentiment analysis, and emotional affect. The purpose of this paper is to evaluate Arabic news posts affect on readers using a novel approach of aspect-based sentiment analysis (ABSA). There are many tasks typically associated with ABSA such as the extraction and polarity identification of aspect terms and categories. The focus of this work is on the tasks related to aspect terms. A typical approach to address these tasks goes through several stages of text pre-processing, features extraction and classification. This paper follows this approach and makes use of widely used features and classifiers. The features considered include Part of Speech (POS) tagging, Named Entity Recognition (NER), and N-Grams. As for the considered classifiers, they are: Conditional Random Fields (CRF), Decision Tree (J48), Naive Bayes and K-Nearest Neighbor (IBk). A set of experiments are conducted to compare the considered classifiers against each other and against a baseline classifier that is very common for ABSA. The results show that the extracted features allow all of the four considered classifiers to significantly outperform the baseline classifier. They also show that J48 performs the best for the task of aspect terms extraction whereas CRF and Naive Bayes are slightly better in aspect terms polarity identification.

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DOI: 10.3217/jucs-022-03-0394

Authors: Vanja Smailovic, Vedran Podobnik

Abstract: In today's networked society where everybody and everything becomes inter-connected, it is very important to be able to identify key actors and key relationships in such a complex multi-layered eco-system. This paper focuses on the specific research challenge of identifying the most influential actors in a social network built through combining relationships among same actors in two different domains - communication domain (proxied through real-world mobile phone communication data) and social networking service domain (proxied through real-world Facebook data). A practical aspect of the paper is evaluated through the SmartSocial Platform, which uses methodology and implements algorithms that enable: i) joining multiple relations among actors across different social networks into the single unified social network; as well as ii) mining created unified social network for identification of most influential actors. Evaluation of the proposed approach is based on the social experiment with 465 users. Experiment results underline two important paper contributions: i) posting frequency sensitivity analysis shows a significant effect of posting frequency on social influence scores; and ii) interdependency analysis shows a synergic effect of combining data from communication and social networking service domains when it comes to calculating influence scores.

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DOI: 10.3217/jucs-021-12-1594

Authors: Shantanu Pal

Abstract: With the tremendous growth of mobile devices, e.g, smartphones, tablets and PDAs in recent years, people are looking for more advanced platforms in order to use their computational applications (e.g., processing and storage) in a faster and more convenient way. In addition, mobile devices are capable of using cloud-based applications and the use of such technology is growing in popularity. However, one major concern is how to efficiently access these cloud-based applications when using a resource-constraint mobile device. Because it requires a continuous Internet connection which is difficult to obtain in challenged environments that lack an infrastructure for communication (e.g., in sparse or rural areas) or areas with infrastructure (e.g., urban or high density areas) with restricted/full of interference access networks and even areas with high costs of Internet roaming. In these situations the use of opportunistic networks may be extended to avail cloud-based applications to the user. In this paper we explore the emergence of extending mobile cloud platforms using opportunistic networks. The motivation of this paper is twofold. First, we classify the available mobile cloud architectures according to their intent, the way they deliver services, and survey the state of the art research and issues related to their performance (e.g., battery power, storage capacity, bandwidth utilisation), environments (e.g., heterogeneity of networks, user's collaborations), robustness (e.g., scalability and availability of resources) and efficiency (e.g., context aware mobile services, access costs, energy consumption). Second, we devise a new `mobile-opportunistic collaborative cloud' (MoCC) architecture which enhances mobile cloud platforms using opportunistic networks. Next, we outline the open issues and future research directions that need to be improved upon for delivering a more scalable, location-aware and context based service to the users.

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DOI: 10.3217/jucs-021-02-0248

Authors: Daniel Perez-Gonzalez, Raimundo Díaz-Díaz

Abstract: Social, technological and economic changes, citizen demand of services modernization, new ICT developments related to the Internet of Things and an economic situation that urges more efficient public administrations, have allowed the adoption of ICT by municipalities in order to provide public services. All the foregoing constitutes a boost of the smart city concept, which is considered in the scientific literature mainly from a technical point of view, overlooking deeper analysis on the specific services being provided by means of smart technologies. The current research identifies services provided using smart technologies at 26 Spanish smart cities and the degree of smart development of those cities based on which services provide. The results highlight that the services most widely implemented are those that allow direct reductions in local administration expenditure. On the other hand, the remaining services enjoy greater perspectives of future development. Additionally, three groups of smart city development have been identified, which allows benchmarking analysis and enhances the exchange of information between the cities.

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DOI: 10.3217/jucs-020-11-1583

Authors: Gia Vo, Richard Lai

Abstract: In recent years, there has been a tremendous growth in e-Government services due to advances in Information Communication Technology and the number of citizens engaging in e-Government transactions. In government administration, it is very time consuming to process different types of documents and there are many data input problems. There is also a need to satisfy citizens’ requests to retrieve government information and to link these requests to build an online document without asking the citizen to input the data more than once. To provide an e-Government service which is easy to access, fast and secure, the e-Document plays an important role in the management and interoperability of e-Government Systems. To meet these challenges, this paper presents a Secure Multilayer e-Application (SMeA) method for improving e-Government processes. This method involves five steps: namely (i) identifying an e-Template; (ii) building a SMeA; (iii) mapping the data; (iv) processing the e-Application; and (v) approving the e-Application. The first step involves requirements analysis and the last four involve data analysis for building a SMeA. To demonstrate its usefulness, we applied SMeA to a case study of an application for a licence to set up a new business in Vietnam.

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DOI: 10.3217/jucs-020-11-1543

Authors: Giansalvatore Mecca, Michele Santomauro, Donatello Santoro, Enzo Veltri

Abstract: We discuss deployment solutions for e-Government Interoperability Frameworks (GIFs). We concentrate on middleware-oriented GIFs, i.e., those in which middleware modules act as intermediaries among information systems that need to exchange data and services. A prominent example is the Italian SPCoop interoperability framework. We review the SPCoop architecture, and two popular open-source implementations of its core modules, called OpenSPCoop and freESBee. We argue that the comparison of these two solutions is relevant since they obey to radically different philosophies, both in terms of the relationship to the underlying J2EE container, and of their internal module organization. Then, we discuss one of the main problems in large-scale deployment of SPCoop-like GIFs, namely the need to quickly deploy a large number of middleware instances over a relatively small number of servers. We report a number of experiments to discuss how the different design choices impact performance. To the best of our knowledge, this is the first large-scale test of the framework, from which a number of important lessons can be learned.

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DOI: 10.3217/jucs-019-15-2292

Authors: Javier Fernández, Juan Augusto, Giuseppe Trombino, Ralf Seepold, Natividad Madrid

Abstract: Traders are required to work in the financial market with highly complex information and to perform efficiently under high levels of psychological pressure. Multiple disciplines, from programs with artificial intelligence to complex mathematical functions, are used to help traders in their effort to maximize profits. However, an essential problem not yet considered in this rapidly evolving environment is that traders are not supported to adequately manage how stress influences their decisions. This paper takes into consideration the negative influences of stress on individuals and proposes a system designed to support traders by providing them with information that can reduce the likelihood of poor decision-making. The system has been designed considering both technical and physiological aspects to make information available in a suitable way. Biometric sensors are used to collect data associated with stress, a software platform then analyses this information and displays it to the trader. The resulting system is capable of making individual traders, as well as teams of traders, self-aware of their levels of stress. The system has been tested in real environments and the results provide evidence that self-aware traders benefit from the system by reducing risky decision-making.

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DOI: 10.3217/jucs-019-12-1703

Authors: Habib Fardoun, Abdulfattah Mashat, Sebastián López

Abstract: In a world where the most used sentences is: "I haven't got the time..." Information Technologies (IT) plays an important role in supporting our daily work, including in everyday educational settings. Such technologies can aid a complete educational system to function successfully so to help the whole school educational life. For this to prove, we present the "Coaching for Teacher" system, a personal technological conversational coach; it aims to provide solutions to overcome difficulties that teachers face during their teaching and learning process. In real time, a teacher can appeal and seek advice rapidly by comfortably talking to an agent. In this paper, we present the steps we followed to design and develop this agent-based application, and a case study conducted in an educational centre for proof that the concept works in an authentic educational environment.

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DOI: 10.3217/jucs-019-07-0950

Authors: Habib Fardoun, Bassam Zafar, Abdulrahman Altalhi, Antonio Paules

Abstract: The design of an educational system involves a good understanding of the whole school environment in order to find the correct approach to develop a comprehensive educational system that will meet real educational needs in their operation. This article describes a design model for an educational system based on the teaching methods applied in the Spanish classrooms, which takes into account new advances in technology, while preserving the current teaching methods in the classroom to ensure a quality teaching and learning process. This development has been achieved by combining technological components such as Cloud Computing, Web Services and Distributed User Interfaces. The proposed system is based on a systematic approach where different phases are implemented, containing workflows and stages.

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DOI: 10.3217/jucs-018-17-2452

Authors: Ajantha Dahanayake, Bernhard Thalheim

Abstract: Although services are developed, used, applied and intensively discussed in nowadays IT practice, the concept of an IT service has not yet been introduced. Services are IT artifacts that can be used by many users in different context at different points of time in different locations and serve a certain purpose. They provide the data and functionality at the best point of time, in the agreed format and quality for the right user with the right location and context. We generalize some of the introduced notions such as the REA framework (resource-event-agent) and introduce a framework for conceptual modeling of IT service systems that is based on the classical rhetorical frame introduced by Hermagoras of Temnos (Quis, quid, quando, ubi, cur, quem ad modum, quibus adminiculis (W7: Who, what, when, where, why, in what way, by what means)). Services are primarily characterized by W4: wherefore (end), whereof (source), wherewith (supporting means), and worthiness ((surplus) value). Additionally, the purpose can be characterized by answering the why, whereto, when, and for which reason W4 questions. The secondary characterization W14H is given by characterizing user or stakeholder (by whom, to whom, whichever), the application domain (wherein, where, for what, wherefrom, whence, what), the solution they are providing (how, why, whereto, when, for which reason), and the additional context (whereat, whereabout, whither, when).

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DOI: 10.3217/jucs-018-15-2187

Authors: María Ibáñez, David Maroto, José Jesús García Rueda, Derick Leony, Carlos Delgado-Kloos

Abstract: 3D virtual worlds are recognized as collaborative learning environments. However, the underlying technology is not sufficiently mature and the virtual worlds look cartoonish, unlinked to reality. Thus, it is important to enrich them with elements from the real world to enhance student engagement in learning activities. Our approach is to build learning environments where participants can either be in the real world or in its mirror world while sharing the same hybrid space in a collaborative learning experience. This paper focuses on the system architecture and a usability study of a proof-of-concept for these hybrid learning environments. The architecture allows the integration of the real world and its 3D virtual mirror; the exchange and geolocalization of multimodal information, and also the orchestration of learning activities. The results of the usability evaluation show positive engagement effects on participants in the mirror world and, to a lesser extent, on those in the real world.

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DOI: 10.3217/jucs-018-09-1152

Authors: Bratislav Predic, Dragan Stojanovic

Abstract: Recent advancements in sensor technologies resulted in the development of sensors with small dimensions and with power consumption that is low enough to be embedded in various mobile devices and which is widely integrated in vehicles. Such sensors can be extensively used to detect real-time traffic events and situations of user/vehicle in context-aware mobile applications. This paper explores the usage of a large number of anonymous mobile devices already involved in the road navigation function as mobile sources of traffic information. Apart from collecting location and speed data, which is extensively used today to calculate average trip time per road segment, we are exploring possibility of using an acceleration sensor integrated with a mobile device in order to efficiently and timely detect critical traffic events and redistribute this information to other drivers through proactive traffic information system. Such a system would be capable of warning drivers of 'near-accident' situations enhancing their situational awareness and general safety.

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DOI: 10.3217/jucs-018-08-0973

Authors: Wilas Chamlertwat, Pattarasinee Bhattarakosol, Tippakorn Rungkasiri, Choochart Haruechaiyasak

Abstract: Traditional approaches for studying consumer behavior, such as marketing survey and focus group, require a large amount of time and resources. Moreover, some products, such as smartphones, have a short product life cycle. As an alternative solution, we propose a system, the Micro-blog Sentiment Analysis System (MSAS), based on sentiment analysis to automatically analyze customer opinions from the Twitter micro-blog service. The MSAS consists of five main functions to (1) collect Twitter posts, (2) filter for opinionated posts, (3) detect polarity in each post, (4) categorize product features and (5) summarize and visualize the overall results. We used the product domain of smartphone as our case study. The experiments on 100,000 collected posts related to smartphones showed that the system could help indicating the customers' sentiments towards the product features, such as Application, Screen, and Camera. Further evaluation by experts in smartphone industry confirmed that the system yielded some valid results.

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DOI: 10.3217/jucs-018-05-0704

Authors: Mabel Vazquez-Briseno, Pierre Vincent, Juan Nieto-Hipolito, Juan Sanchez-Lopez

Abstract: The development of mobile applications and services has led to new challenges for software programmers. One of the main differences from standard PC programming is that the mobile environment is still limited in several aspects. Thus, there are many applications for mobile devices that share similarities, and implementing new applications may result in duplicated code within the same project or in similar projects. Moreover, current mobile development is still an error-prone task that may produce difficult-to-maintain applications. As a result, developers need new tools to help them to develop mobile software efficiently. This work focuses on a new framework for generating mobile applications and services, MobAppGen. The framework provides a set of components called modules that can be used to construct new applications using a Web interface. The architecture and functionalities of the framework are delineated, and several tests were conducted to evaluate the performance of the framework. For the tests, we created a number of projects using the available modules. In addition, a survey was conducted to estimate the acceptance and usefulness of the framework.

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DOI: 10.3217/jucs-018-04-0577

Authors: Anna Zygmunt, Piotr Bródka, Przemysław Kazienko, Jarosław Koźlak

Abstract: Identifying key persons active in social groups in the blogosphere is performed by means of social network analysis. Two main independent approaches are considered in the paper: (i) discovery of the most important individuals in persistent social communities and (ii) regular centrality measures applied either to social groups or the entire network. A new method for separating of groups stable over time, fulfilling given conditions of activity level of their members is proposed. Furthermore, a new concept for extracting user roles and key persons in such groups is also presented. This new approach was compared to the typical clustering method and the structural node position measure applied to rank users. The experimental studies have been carried out on real two-year blogosphere data.

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DOI: 10.3217/jucs-017-13-1800

Authors: M. Cambronero, Valentín Valero, Enrique Martínez

Abstract: In this paper we show how UML 2.0 sequence diagrams can be used for the design of Web service choreographies with time constraints and how these sequence diagrams can be extended with frames for the description of Web service choreographies. We then show how the diagrams can be translated into WS-CDL documents. This translation is of interest, since non-XML experts can find it difficult to implement a composite web service by WS-CDL, i.e. XML code. Graphic models, such as UML sequence diagrams, are a popular and well-studied framework for a compact representation of interoperation among participants in a distributed system and can be used as a starting document for the design of a composite Web service, from which the corresponding WS-CDL document can be derived.

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DOI: 10.3217/jucs-017-10-1430

Authors: Alice Comi, Martin Eppler

Abstract: As suggested by several scholars, inter-organizational collaboration is an important vehicle for innovation, but working across organizational boundaries entails great complexity. In this paper, we argue that visual facilitation may act as a catalyst of inter-organizational teamwork, leading to increased knowledge sharing quality (H1), team performance (H2) and satisfaction (H3). On the other hand, we suggest that the aesthetic beauty of visual representations may exert a manipulatory effect, inducing inter-organizational actors to overestimate the collaboration value potential (H4). We adopt an experimental design (N=145 participants) in order to assess the advantages and disadvantages of visual facilitation in inter-organizational teamwork. In particular, we compare inter-organizational teams working with i) software-based visualization, ii) poster-based visualization, and iii) text-based facilitation (control condition). By comparing results across the two treatment conditions (software and poster), we disentangle the effects of visual facilitation and computer interactivity, therefore making a unique contribution to research on information visualization. The experiment findings show that software-supported teams outperform the control groups in terms of performance (H2), and exhibit greater satisfaction with the inter-organizational meetings (H3). We extend our experimental study by conducting focus groups with 17 experiment participants to gain an in-depth understanding of the users' experience with the different support systems. After discussing relevant implications for both researchers and practitioners, we point out the limitations of our study and suggest directions for future research.

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DOI: 10.3217/jucs-017-06-0891

Authors: Yi-Li Huang, Fang-Yie Leu, Chao-Hong Chiu, I-Long Lin

Abstract: Recently, IEEE 802.16 Worldwide Interoperability for Microwave Access (WiMAX for short) has provided us with low-cost, high efficiency and high bandwidth network services. However, as with the WiFi, the radio wave transmission also makes the WiMAX face the wireless transmission security problem. To solve this problem, the IEEE802.16Std during its development stage defines the Privacy Key Management (PKM for short) authentication process which offers a one-way authentication. However, using a one-way authentication, an SS may connect to a fake BS. Mutual authentication, like that developed for PKMv2, can avoid this problem. Therefore, in this paper, we propose an authentication key management approach, called Diffie-Hellman-PKDS-based authentication method (DiHam for short), which employs a secret door asymmetric one-way function, Public Key Distribution System (PKDS for short), to improve current security level of facility authentication between WiMAX’s BS and SS. We further integrate the PKMv1 and the DiHam into a system, called PKM-DiHam (P-DiHam for short), in which the PKMv1 acts as the authentication process, and the DiHam is responsible for key management and delivery. By transmitting securely protected and well-defined parameters for SS and BS, the two stations can mutually authenticate each other. Messages including those conveying user data and authentication parameters can be then more securely delivered.

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DOI: 10.3217/jucs-017-02-0311

Authors: Andreas Kuswara, Debbie Richards

Abstract: With the emergence of the Web 2.0 phenomena, technology-assisted social networking has become the norm. The potential of social software for collaborative learning purposes is clear, but as yet there is little evidence of realisation of the benefits. In this paper we consider Information and Communication Technology student attitudes to collaboration and via two case studies the extent to which they exploit the use of wikis for group collaboration. Even when directed to use a particular wiki designed for the type of project they are involved with, we found that groups utilized the wiki in different ways according to the affordances ascribed to the wiki. We propose that the integration of activity theory with an affordances perspective may lead to improved technology, specifically Web 2.0, assisted collaboration.

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DOI: 10.3217/jucs-016-21-3314

Authors: Gerhard Wurzinger

Abstract: Due to information technologies the problem we are facing today is not a lack of information but too much information. This phenomenon becomes very clear when we consider two figures that are often quoted: Knowledge is doubling in many fields (biology, medicine, computer science, ...) within some 6 years; yet information is doubling every 8 months! This implies that the same piece of information/knowledge is published a large number of times with small variations. Just look at an arbitrary news item. If considered of some general interest reports of it will appear in all major newspapers, journals, electronic media, etc. This is also the problem with information portals that tie together a number of large databases. It is our contention that we need methods to reduce the huge set of information concerning a particular topic to a number of pieces of information (let us call each such piece an "essay" in what follows) that present a good cross-section of potential points of view. We will explain why one essay is usually not enough, yet the problem of reducing a huge amount of contributions to a digestible number of essays is formidable, indeed is science fiction at the moment. We will argue in this paper that it is one of the important tasks of computer sciences to start tackling this problem, and we will show that in some special cases partial solutions are possible.

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DOI: 10.3217/jucs-015-16-3139

Authors: Torsten Holmer, Stephan Lukosch, Verena Kunz

Abstract: In this article, we address the problem of confusion and co-text-loss in chat communication, identify requirements for a solution, discuss related work and present a new approach for addressing co-text loss in text-based chats. We report about first experiences with our solution and give an outlook on future work directions. The core idea of our solution MuViChat (multiple-visualization chat) is to support multiple visualizations of referenced chat transcripts in which users can choose their preferred view. The multiple visualizations offer different possibilities to follow and understand a communication and thereby diminish chat confusion which often occurs in standard chat systems. By enabling the recording and replaying of chat discussions and an extensible modular architecture we are supporting evaluation and further integration of advanced visualization concepts.

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DOI: 10.3217/jucs-015-13-2485

Authors: Vu Tan, Dae-Seung Yoo, Jun-Chol Shin, Myeong-Jae Yi

Abstract: This paper presents the architecture of a multiagent system based on new OPC Unified Architecture (UA) technology for hierarchical control and monitoring of a complex process control system. This architecture is proposed with utilization of the OPC technology, which contains both a continuous-event component and a discreteevent component by incorporating XML for the negotiation and cooperation with the multiagent system's environments. The practical applications of the proposed architecture are provided and the discussion demonstrates that the proposed architecture is both reliable and effective for applying to multiagent-based complex control system applications.

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DOI: 10.3217/jucs-015-12-2429

Authors: Chun Ruan, Sang-Soo Yeo

Abstract: Due to rapid advances of computing power and communications, healthcare services are increasingly rely on the electronic processing and transmission of confidential patient data to reduce the costs and improve the quality. It is becoming more and more important that accessing the health information should be both secure and privacy preserving. Therefore access control becomes an important integral part of any secure healthcare computer software systems. Specification of access control requirements at early steps of the software life cycle can provide stakeholders rapid feedback and protect the system in a best possible way. On the other hand, intelligent systems are widely used in various computing areas ranging from medicine to manufacturing industries to financial markets. This paper studies how to model an intelligent e-Consent system about the security requirements regarding healthcare information protection. In this paper, we use UML to specify and visualize the access control policies in a health application domain. These policies are represented in logic based e-Consent rules, and the patient’s consents about their information access can be derived from these rules. We first identify various parts necessary to specify the e-Consent rules about patient record protection requirements, and then propose UML models to demonstrate these requirements.

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DOI: 10.3217/jucs-015-10-2109

Authors: Sohei Ikeda, Takakazu Nagamine, Tomio Kamada

Abstract: We are developing a new mashup framework for creating flexible applications in which users can selectively browse through mashup items. The framework provides GUI components called widgets through which users can browse mashed-up data selectively, and the system processes demand-driven creation of mashed-up data upon receiving access requests through widgets. The application developer has to only prepare a configuration file that specifies how to combine web services and how to display mashed-up data. This paper proposes a revised widget model for effective data display, and introduces practical applications that allow selective browsing. The revision of the widget model is to accept various GUI components, process user interactions, and provide cooperative widgets. To avoid conflict with lazy data creation, we introduce properties into widgets that are automatically maintained by the system and can be monitored by other widgets. The case study through the applications shows the situations where the initially browsed data helps users to terminate redundant searches, set effective filter settings, or change the importance of the criteria. Some applications display synoptic information through columns, maps, or distribution charts; such information is useful for selective browsing.

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DOI: 10.3217/jucs-015-09-2011

Authors: Ting Peng, Qinghua Zheng, Yinli Jin

Abstract: In Peer-to-Peer(P2P) streaming system, the multicasting tree construction method influences considerably on network load. Under current available strategies, network resources are not used economically, or network resource friendship and the flexibility can't be approached thoroughly. With the increasing application of Internet, network infrastructure itself becomes a precious resource, which should be performed effectively. In our implementation, network transmission delay between the peers is detected, used as practical performance metrics of the P2P streaming system. According to the metrics, network friendly tree is provided as overlay multicasting tree construction strategy for P2P streaming system. In this strategy, additional transmission delays are minimized as new peers enter. The simulation experiment presents that the proposed strategy network friendly tree works better than other contrasts. And the transmission performance improves significantly at minor additional cost.

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DOI: 10.3217/jucs-015-09-1924

Authors: Yong Xiang, Shaohua Zhang, Yuzhu Shen, Meilin Shi

Abstract: Automatic workflow generation is becoming an active research area for dealing with the dynamics of grid infrastructure, because it has a pervasive impact on system usability, flexibility and robustness. Artificial intelligence technology and explicit knowledge have been exploited in some research for workflow construction or composition. With the increasing use of knowledge, its quality has growing impact on system performance. In this report, we present the process pattern as a vehicle for knowledge representation to capture process expertise at the business level. A pattern-based planning approach is proposed for automated workflow generation. Our pattern-oriented approach decreases user-visible complexity and makes systems more scalable and flexible by utilizing explicit knowledge support. Then we propose a hybrid method of pattern knowledge optimization for pattern-based workflow generation planning; experts define the primary model, and subsequent classifier training adjusts and improves the pattern knowledge settings. Experiments with a prototype application demonstrated that this approach can substantially reduce modelling difficulties and effectively improve pattern knowledge quality.

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DOI: 10.3217/jucs-015-08-1735

Authors: Ulrica Pettersson

Abstract: Developing successful knowledge management (KM) processes is extremely difficult. In general, a large number of all KM projects end unsuccessfully. The aim of this paper is to summarize and study the attempts to take advantage of Lessons Learned in the Swedish Armed Forces (SwAF), focusing on international missions. Relevant reports, articles and literature have been studied. With the purpose of understanding the reasons for failure and the failure factors in SwAF’s attempts at KM, Chua and Lam’s model for unsuccessful KM implementation has been applied to four cases from the organization. The results show that SwAF are aware of the importance of knowledge and have attempted to implement KM on several occasions. In most cases, however, the KM projects do not achieve widespread use and eventually end unsuccessfully. Furthermore, many of the KM tools that have been developed are no longer in use. The Swedish Explosive Ordnance Disposal and Demining Centre (SWEDEC) and the Swedish Air Force are notable exceptions.

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DOI: 10.3217/jucs-015-08-1589

Authors: Junseok Hwang, Youngjin Lee, Seunghyun Kim

Abstract: Weblogs have received attention as new, personalized media. Yet, only few of them attract public attention and become successful. This study explores weblog success factors in three categories: content creation, content features and content diffusion. During the process of content creation in weblogs, we argue that weblog service providers (WSPs) support bloggers’ resource collection. We also presume that the volume or the quality of posts in weblogs could be matter to gain visitors’ attention when weblog content (i.e., post) is generated. During the process of content diffusion, we assume that use of blogging technologies (BTs) such as trackback or RSS would enhance content-sharing activities between weblogs. Based on the data from a sample of Korean individual weblogs, our analysis indicates that weblog success (in terms of the number of unique visitors per week) is related to the WSP’s support level for content creation as well as content features.

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DOI: 10.3217/jucs-015-05-1065

Authors: Jong Park

Abstract: Ubi-Com has emerged as an exciting new paradigm to provide intelligent computig and communications at anytime and anywhere. But, In order to take the advantages of such services, it is important that intelligent security framework be suitable for Ubi-Com. In this paper, we propose privacy and access control scheme by surveillance which is one of core security technologies for ubiquitous hybrid intelligent security framework. In this scheme, the device information and the signature information can be added to the image data obtained by the image capturing device to maintain security of the image data and use the image data as digital proof when a specific event is generated.

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DOI: 10.3217/jucs-015-03-0665

Authors: Andreas Schmeil, Martin Eppler

Abstract: In this paper we propose a classification and systematic description structure based on the pattern paradigm for interaction scripts in Second Life that aim at facilitating on the one side knowledge sharing and knowledge integration in groups, and on the other side knowledge creation in formal and informal ways. We present 13 examples of interaction patterns, a description structure to formalize them, and classify them into four classes according to their design effort and added value. Based on this classification we distinguish among sophisticated 3D collaboration patterns, seamless patterns, decorative patterns, and pseudo patterns.

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DOI: 10.3217/jucs-015-03-0648

Authors: Sergio Toral, Rocío Torres, Federico Barrero

Abstract: One of the benefits firms can derive from using Open Source Software (OSS) is informal development collaboration, and the primary tool for collaboration and coordination are group mailing lists. The purpose of the paper is modelling mailing lists behaviour in OSS projects, using a set of descriptors that could inform about their quality and their evolution. As a case study, a mailing list focused on ARM embedded Linux has been selected. Messages posted to this list from 2001 to 2006 have been extracted, and factor analysis has been applied to obtain the underlying patterns of behaviours. Theory about communities of practice has been used to understand the meaning of the extracted patterns. Their time distribution is finally described. The paper provides new insights into the behaviour of mailing list as a source of support for OSS projects and highlights the importance of an involved core of individuals inside the community.

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DOI: 10.3217/jucs-014-12-2034

Authors: Michael Altenhofen, Andreas Friesen, Jens Lemcke

Abstract: We give a survey on work we did in the past where we have successfully applied the ASM methodology to provide abstract models for a number of problem areas that are commonly found in Service Oriented Architectures (SOA). In particular, we summarize our work on (1) service behavior mediation, (2) service discovery, and (3) service composition, showing that the corresponding solutions can be described as variations of a fundamental abstract processing model—the Virtual Provider.

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DOI: 10.3217/jucs-014-10-1695

Authors: Muhammad Khan, Narayanan Kulathuramaiyer, Hermann Maurer

Abstract: The WWW is currently experiencing a revolutionary growth due to numerous emerging tools, techniques and concepts. Digital journals thus need to transform themselves to cope with this evolution of the web. With their growing information size and access, conventional techniques for managing a journal and supporting authors and readers are becoming insufficient. Journals of the future need to provide innovative administrative tools in helping its managers to ensure quality. They also need to provide better facilities for assisting authors and readers in making decisions regarding their submission of papers and in providing novel navigational features for finding relevant publications and collaborators in particular areas of interest. In this paper, we explore an innovative solution to address these problems by using an emerging Web 2.0 technology. We explore the application of mash-ups for J.UCS - the Journal of Universal Computer Science and encourage readers and authors to try out the applications (see section 11 Conclusions). J.UCS can then serve as a model for contemporary electronic journals.

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DOI: 10.3217/jucs-014-09-1463

Authors: Rafael Duque, Jesús Gallardo, Crescencio Bravo, Antonio Mendes

Abstract: Most of the current academic and professional work requires collaboration between the members of a working group. Groupware tools play a prevailing role in supporting this collaborative work, often from different locations and at the same time. The research field of CSCW (Computer-Supported Cooperative Work) studies how to design effective groupware tools. To increase their potential, groupware systems must be flexible and have the capacity to adapt themselves to multiple tasks and situations. In order to provide answers to these challenges, in this article we propose the use of meta-models and XML-based languages to specify the most important characteristics of a groupware modeling system, such as the application domain, the requirements of the tasks to be carried out, how communication takes place and the regulation of the shared workspace. These models and techniques have been used to develop a specific groupware system called SPACE-DESIGN (SPecification and Automatic Construction of collaborative Environments of DESIGN), a CSCW tool with support for synchronous distributed collaborative work that adapts and re-configures itself as a result of processing the domain specification, the task, the communication and the system working norms.

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DOI: 10.3217/jucs-014-08-1314

Authors: Marcelo Alves, Paulo Pires, Flávia Delicato, Maria Luiza M. Campos

Abstract: Nowadays, the complexity of software applications has brought new challenges to developers, having to deal with a large number of computational requirements. Among these requirements, those known as crosscutting concerns transpass components boundaries, leading to maintainability and comprehension problems. This paper presents CrossMDA, a framework that encompasses a transformation process to integrate crosscutting concerns in model-oriented systems. It uses the concepts of horizontal separation of concerns from AOP to create independent business and aspect models, integrating those models through MDA transformations (vertical separation of concerns). CrossMDA comprises a development process, a set of services and support tools. The main advantages of this approach are to raise the abstraction level of aspect modeling, to promote the reuse of crosscutting concerns modeled as PIM elements, besides automating the process of mapping the relationship of crosscutting concerns and business models through the process of MDA transformations.

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DOI: 10.3217/jucs-014-05-0717

Authors: Zbigniew Hulicki

Abstract: Development of e-services in the CE (Central European) countries d epends on a number of factors which can result in overcoming or extending digital divide between the "new" and "old" EU member states. These factors comprise both drives of and barriers to development of broadband access and growth of e-services. This paper provides insight into the environment for the CE mass-market broadband adoption, and examines each of the factors that condition this adoption: novel approaches to increase ICT penetration; clear policy and legal regulations; segmented service offerings for specific user needs in such markets ; and innovative pricing schemes and service packages.

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DOI: 10.3217/jucs-014-04-0546

Authors: Christian Safran, Frank Kappe

Abstract: User generated content published via weblogs (also known as blogs) has gained importance in the last years, and the number of globally available weblogs increases. However, a large fraction of these show low publishing activity and are rarely read. This paper is a quantitative analysis of success factors in a community of over 15.000 weblogs, hosted by a local Austrian newspaper. We looked at publishing activity by content type, community activity and writing style. Also, the interconnectedness of the community was analyzed.

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DOI: 10.3217/jucs-014-04-0526

Authors: Claudia Müller, Benedikt Meuthrath, Anne Baumgraß

Abstract: Increasingly wikis are used to support existing corporate knowledge exchange processes. They are an appropriate software solution to support knowledge processes. However, it is not yet proven whether wikis are an adequate knowledge management tool or not. This paper presents a new approach to analyze existing knowledge exchange processes in wikis based on network analysis. Because of their dynamic characteristics four perspectives on wiki networks are introduced to investigate the interrelationships between people, information, and events in a wiki information space. As an analysis method the Social Network Analysis (SNA) is applied to uncover existing structures and temporal changes. A scenario data set of an analysis conducted with a corporate wiki is presented. The outcomes of this analysis were utilized to improve the existing corporate knowledge processes.

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DOI: 10.3217/jucs-014-03-0441

Authors: Guomin Yang, Duncan Wong, Xiaotie Deng

Abstract: In a secure roaming scenario, a user U travels to a foreign network and communicates with a foreign server V securely so that no one other than U and V can obtain the messages exchanged between them. U may also want to travel anonymously so that no one including V can find out its identity or trace its whereabouts except its home server H. There have been many key establishment protocols proposed for secure roaming. A typical application of these protocols is the mobile roaming service which may be deployed to interconnected WLAN and 3G networks. Despite the importance of these protocols, most of the protocols are analyzed heuristically. They are lack of formal security treatment. In this paper, we propose a formal key exchange definition and formalize secure roaming under the Canetti-Krawczyk (CK) model. We also propose a formal model for capturing the notions of user anonymity and untraceability. By using the modular approach supported by the CK-model, we construct an efficient key exchange protocol for roaming and then extend it to support user anonymity and untraceability. The protocols are efficient and each of them requires only four message flows among the three parties U, H and V. For building our protocols, we construct a one-pass counter based MT-authenticator and show its security under the assumption of a conventional MAC secure against chosen message attack.

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DOI: 10.3217/jucs-014-03-0416

Authors: Liqun Chen, Qiang Tang

Abstract: Unknown Key-Share (UKS) resilience is a basic security attribute in authenticated key agreement protocols. In this paper we revisit the definitions of this attribute and the method of proving this attribute under the Bellare-Rogaway (BR) model in the literature. We propose a new type of UKS attack, which coerces two entities A and B into sharing a key with each other but in fact A thinks that he is sharing the key with another entity C and B thinks that he is sharing the key with another entity D, where C and D might or might not be the same entity. We call this attack a Bilateral Unknown Key-Share (BUKS) attack. We demonstrate that a few well-known authenticated key agreement protocols are vulnerable to this attack. We then explore a gap between the conventional BR-type proof and a BUKS adversary's behavior, and extend the BR model to cover the BUKS resilience attribute. At the end of the paper, we provide a general countermeasure and its security proof under the extended model and the assumption that a collision-resistance function exists.

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DOI: 10.3217/jucs-014-03-0318

Authors: Yeveniy Dodis, Pil Lee, Dae Yum

Abstract: This paper addresses the security of optimistic fair exchange in a multi-user setting. While the security of public key encryption and public key signature schemes in a single-user setting guarantees the security in a multi-user setting, we show that the situation is different in the optimistic fair exchange. First, we show how to break, in the multi-user setting, an optimistic fair exchange scheme provably secure in the single-user setting. This example separates the security of optimistic fair exchange between the single-user setting and the multi-user setting. We then define the formal security model of optimistic fair exchange in the multi-user setting, which is the first complete security model of optimistic fair exchange in the multi-user setting. We prove the existence of a generic construction meeting our multi-user security based on oneway functions in the random oracle model and trapdoor one-way permutations in the standard model. Finally, we revisit two well-known methodologies of optimistic fair exchange, which are based on the verifiably encrypted signature and the sequential two-party multisignature, respectively. Our result shows that these paradigms remain valid in the multi-user setting.

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DOI: 10.3217/jucs-014-01-0027

Authors: Guillermo Vega-Gorgojo, Miguel Bote-Lorenzo, Eduardo Gómez-Sánchez, Juan Asensio-Pérez, Yannis Dimitriadis, Iván Jorrín-Abellán

Abstract: Collaborative learning systems can be constructed following the serviceoriented computing paradigm. This allows educators to integrate external tools, offered as services by software providers, in order to support the realization of collaborative learning situations. Discovering appropriate services is a challenging task that requires the description of their capabilities. This can be accomplished with Ontoolcole, an ontology of collaborative learning tools designed with the aim of supporting educators in the search of CSCL tools. Ontoolcole is depicted here and some new, relevant features are discussed. Namely, Ontoolcole incorporates an artifact module, a task-level coordination module and the description of static information resources, further improving the capabilities to describe complex CSCL tools. As a proof of concept, we also present a preliminary prototype of the intended target application of Ontoolcole, an interactive system for the search of CSCL tools, named Ontoolsearch. A case study with practitioners has been carried out to evaluate whether Ontoolcole can be employed by educators to search CSCL tools. Evaluation results show that Ontoolcole abstractions fit educators' questions based on their real practice while retrieving useful tools for their educational needs.

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DOI: 10.3217/jucs-014-01-0004

Authors: Werner Geyer, Roberto S. Silva Filho, Beth Brownholtz, David Redmiles

Abstract: Contextual collaboration seamlessly integrates existing groupware technologies into a uniform user experience that combines synchronous and asynchronous interactions. This user experience is usually supported by a collaboration infrastructure that needs to efficiently cope with the fast switching and integration of different modes of interaction. In this paper, we study a model for contextual collaboration that supports multiple modalities of collaboration. Our model is based on generic shared objects that provide building blocks for supporting contextual collaboration applications. We describe a native implementation of this model and evaluate its behavior under different media traffic conditions. We compare the native implementation with an alternative implementation that integrates existing notification and meeting servers to deliver the same model behavior. We discuss trade-offs and limitations of those two implementations.

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DOI: 10.3217/jucs-013-07-1002

Authors: Gregory Heileman, Chaouki Abdallah, Wei Shu, Christos Christodoulou, Debby Knotts

Abstract: This paper describes the motivation, strategies, and implementation details that lead to the creation of online graduate-level degree programs in the Department of Electrical & Computer Engineering at the University of New Mexico. It also presents some of the benefits as well as the challenges encountered when designing and implementing these programs. The paper concludes with a discussion of lessons learned and the future directions of the program.

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DOI: 10.3217/jucs-013-04-0531

Authors: Narayanan Kulathuramaiyer

Abstract: The WWW is currently experiencing a revolutionary growth due to its increasing participative community software applications. This paper highlights an emerging application development paradigm on the WWW, called mashup. As blogs have enabled anyone to become a publisher, mashups stimulate web development by allowing anyone to combine existing data to develop web applications. Current applications of mashups include tracking of events such as crime, hurricanes, earthquakes, meta-search integration of data and media feeds, interactive games, and as an organizer for web resources. The implications of this emerging web integration and structuring paradigm remains yet to be explored fully. This paper describes mashups from a number of angles, highlighting current developments while providing sufficient illustrations to indicate its potential implications. It also highlights the role of mashups in complementing and enhancing digital journals by providing insights into the quality academic content, extent of coverage, and the enabling of expanded services. We present pioneering initiatives for the Journal of Universal Computer Science in our efforts to harness the collective intelligence of a collaborative scholarly network.

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DOI: 10.3217/jucs-012-10-1439

Authors: Rajasvaran Logeswaran

Abstract: When dealing with remote systems, it is desirable that these systems are capable of operation within acceptable levels with minimal control and maintenance. In terms or transmission of telemetry information, a prediction-based compression scheme has been introduced. This paper studies the influence of some typical transmission and network errors on the encoded residue stream produced by a number of predictors used in the scheme, with the intention of identifying the more fault tolerant architecture that may be preferred as predictors. Classical linear predictors such as FIR and lattice filters, as well as a variety of feedforward and recurrent neural networks are studied. The residue streams produced by these predictors are subjected to two types of commonly occurring transmission noise, namely gaussian and burst. The noisy signal is decoded at the receiver and the magnitude of error, in terms or MSE and MAE are compared. Hardware failures in the input receptor and multiplier are also simulated and the performance of various predictors is compared. Overall, it is found that even small low-complexity neural networks are more resilient to faults due to the characteristics of their parallel architecture and distributed storage/processing characteristics.

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DOI: 10.3217/jucs-012-09-1208

Authors: Pawel Gocek, Michael Hartmann, Heinz Schleusener

Abstract: The internet is an unlimited growing and most comfortable information and communication base. In this context, web portals on the internet play an important role created for combining communication facilities and information data bases. An increasing number of portals involve web-based map applications to integrate geographic information for the representation of economical and other records. Web-based map applications are typically designed in a client-server architecture. Different solutions exist using especially HTML and JavaScript, Flash or Java applets. We discuss these possibilities and point out an alternative solution. Particularly, we show how to use Java Applet Technology and Asynchronous JavaScript and XML (Ajax) in this field. Finally, we report about our results as a complete, flexible map service solution which is available on the internet. An adapted kind of solution will be used by a geo-based marketing portal for offering information about the economic situation, social and cultural aspects and natural facts of regions to support joint-ventures inside the European Union.

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DOI: 10.3217/jucs-012-09-1128

Authors: Balázs Benyó, Miklós Hatwágner, Tamás Heckenast, Katalin Kovács, Ágnes Varga, Norbert Varjasi

Abstract: ENUM is a technology based on a procedure that assigns a sequence of traditional telephone numbers to Internet domain names. It specifies a rule that makes it possible to relate a domain to a telephone number without any risk of ambiguity. This domain can then be used to identify various communication services like fax, mobile phone numbers, voice-mail systems, e-mail addresses, IP telephone addresses, web pages, GPS coordinates, call diverts or unified messaging. In our paper we deal with three main problem areas in connection with the business model of the ENUM service and with the introduction of new services, i.e. the questions of tariffs, legal regulations and financial return. For the ENUM procedure to spread out in use specific services have to be implemented that can exploit the advantages of the ENUM and efficient methods have to be elaborated to base existing services on ENUM. We will outline the two new services invented by our group and that we have implemented in our project.

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DOI: 10.3217/jucs-012-09-1104

Authors: Attila Adamkó

Abstract: Recently a growing demand has arisen for methods for the development of small- and medium scale Web Information Systems (WIS). Web applications are being built in a rapidly changing environment where requirements are usually unstable. Short-time design and implementation are needed in response to the new technologies. Our work focuses rather on the design and construction of Web applications, than management. Flexibility is a major requirement in such applications, and also in a database-backed environment for the structure and presentation of the sites. We propose a systematic design method for Web applications which takes into account the data-oriented aspects of the application. The method is based on a UML profile adapted to the problem domain by means of stereotypes as well as a strategy for generating code templates from such models. We provide a method to derive the navigation model from the structural model of a Web application. We will also show guidelines for the development of the Data Layer of data-oriented Web application. Moreover, why to divide the business logic layer into two parts: the pure application logic for managing the workflow of the application and the storage logic responsible for the data structures. Rapid development is enabled by providing roundtrip engineering capabilities with support for automatic code generation. We will show the role of XML: why to use XML to support both the reuse of content and context-dependent delivery. An advantage of the proposed methodology is that several steps can be performed is a semi-automatic way providing rapid development and prototyping.

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DOI: 10.3217/jucs-012-02-0187

Authors: Josef Kolbitsch, Hermann Maurer

Abstract: To date, one of the main aims of the World Wide Web has been to provide users with information. In addition to private homepages, large professional information providers, including news services, companies, and other organisations have set up web-sites. With the development and advance of recent technologies such as wikis, blogs, podcasting and file sharing this model is challenged and community-driven services are gaining influence rapidly. These new paradigms obliterate the clear distinction between information providers and consumers. The lines between producers and consumers are blurred even more by services such as Wikipedia, where every reader can become an author, instantly. This paper presents an overview of a broad selection of current technologies and services: blogs, wikis including Wikipedia and Wikinews, social networks such as Friendster and Orkut as well as related social services like del.icio.us, file sharing tools such as Flickr, and podcasting. These services enable user participation on the Web and manage to recruit a large number of users as authors of new content. It is argued that the transformations the Web is subject to are not driven by new technologies but by a fundamental mind shift that encourages individuals to take part in developing new structures and content. The evolving services and technologies encourage ordinary users to make their knowledge explicit and help a collective intelligence to develop.

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DOI: 10.3217/jucs-012-01-0099

Authors: Zhenjiang Miao, Baozong Yuan, Mengsun Yu

Abstract: This paper proposes a Human-centered Pervasive Computing System Model (HPC), a Layered Architectural Analysis and Design Method (LAAD) and a Waterfall Prototyping Process Model (WPP). Based on the HPC model and the LAAD method, a pervasive computing based multimodal tele-home healthcare system is designed and partly implemented using the Waterfall Prototyping Process. The design and implementation issues are discussed in more detail. Some testing results are presented.

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DOI: 10.3217/jucs-012-01-0045

Authors: Timothy Sullivan, John Donoghue, John Herbert, Richard Studdert

Abstract: Telemedicine applications on a medical practitioner's mobile device should be context-aware. This can vastly improve the effectiveness of mobile applications and is a step towards realising the vision of a ubiquitous telemedicine environment. The nomadic nature of a medical practitioner emphasises location, activity and time as key context-aware elements. An intelligent middleware is needed to effectively interpret and exploit these contextual elements. This paper proposes an agent-based architectural solution called Context-Aware Mobile Medical Devices (CAMMD). This framework can proactively communicate patient records to a portable device based upon the active context of its medical practitioner. An expert system is utilised to cross-reference the context-aware data of location and time against a practitioner's work schedule. This proactive distribution of medical data enhances the usability and portability of mobile medical devices. The proposed methodology alleviates constraints on memory storage and enhances user interaction with the handheld device. The framework also improves utilisation of network bandwidth resources. An experimental prototype is presented highlighting the potential of this approach.

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DOI: 10.3217/jucs-012-01-0030

Authors: Haiying Zhou, Kun Hou, Laurent Gineste, Christophe Vaulx, Jean Ponsonnaille

Abstract: More than 60,000 people die suddenly each year in France due to cardiac arrhythmias. The current techniques used to diagnose cardiac arrhythmias such as HOLTER, R.TEST and telemetry system are partially efficient owing to the limitation of the duration of monitoring. This paper presents a new system dedicated to real-time cardiac arrhythmias tele-assistance and monitoring. This system is generally composed of 4 main configurable elements: wireless ECG sensor, local access unit, remote centre server, and remote surveillance terminal. The main technical challenges of this system include three aspects: a real-time automatic ECG diagnostic algorithm, an embedded real-time multi-task operating system, and a real-time reliable telemedicine communication protocol. This paper gives our solutions to these problems and specifies the technical details. Currently, this system has been evaluated on thirty patients at the CHRU of Gabriel Montpied hospital (Clermont-Ferrand, France) and also been used to test the athletes' cardiac status during the physical exercises. The performance results show that this system meets fully the requirements of real-time cardiac monitoring and diagnosing application and can be used as a long-term cardiac healthcare equipment.

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DOI: 10.3217/jucs-011-04-0452

Authors: Norbert Gronau, Claudia Müller, Roman Korf

Abstract: Existing approaches in the area of knowledge-intensive processes focus on integrated knowledge and process management systems, the support of processes with KM systems, or the analysis of knowledge-intensive activities. For capturing knowledge-intensive business processes well known and established methods do not meet the requirements of a comprehensive and integrated approach of process-oriented knowledge management. These approaches are not able to visualise the decisions, actions and measures which are causing the sequence of the processes in an adequate manner. Parallel to conventional processes knowledge-intensive processes exist. These processes are based on conversions of knowledge within these processes. To fill these gaps in modelling knowledge-intensive business processes the Knowledge Modelling and Description Language (KMDL) got developed. The KMDL is able to represent the development, use, offer and demand of knowledge along business processes. Further it is possible to show the existing knowledge conversions which take place additionally to the normal business processes. The KMDL can be used to formalise knowledge-intensive processes with a focus on certain knowledge-specific characteristics and to identify process improvements in these processes. The KMDL modelling tool K-Modeler is introduced for a computer-aided modelling and analysing. The technical framework and the most important functionalities to support the analysis of the captured processes are introduced in the following contribution.

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DOI: 10.3217/jucs-011-02-0303

Authors: Frantisek Capkovic

Abstract: An application of the method suitable for modelling and control of general discrete event dynamic systems (DEDS) to special kinds of communication systems is presented in this paper. The approach is based on Petri nets (PN) defined in [Peterson 1981] and directed graphs (DG) described e.g. in [Diestel 1997]. It is supported by the previous author s works, especially [Capkovic 2003], [Capkovic 1998], [Tzafestas and Capkovic 1997].

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DOI: 10.3217/jucs-010-03-0262

Authors: John Davies, Alistair Duke, York Sure

Abstract: An ontology-based knowledge sharing system OntoShare and its evaluation as part of a case study is described. RDF(S) is are used to specify and populate an ontology, based on information shared between users in virtual communities. We begin by discussing the advantages that use of Semantic Web technology afford in the area of knowledge management tools. The way in which OntoShare supports WWW-based communities of practice is described. Usage of OntoShare semiaautomatically builds an RDF-annotated information resource for the community (and potentially for others also). Observing that in practice the meanings of and relationships between concepts evolve over time, OntoShare supports a degree of ontology evolution based on usage of the system - that is, based on the kinds of information users are sharing and the concepts (ontological classes) to which they assign this information. A case study involving OntoShare was carried out. The evaluation exercise for this case study and its results are described. We conclude by describing avenues of ongoing and future research.

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DOI: 10.3217/jucs-010-01-0014

Authors: Maja Pivec, Olga Dziabenko

Abstract: How to design effective learning opportunities? Why is learning by experience often more efficient than learning by studying? How to provide the learning experiences needed to respond to current challenges? Using computer games and games in general for educational purposes offers a variety of knowledge presentations and creates opportunities to apply the knowledge within a virtual world, thus supporting and facilitating learning processes. An innovative educational paradigm such as game-based learning, which is considered suitable for the given purpose, is described in this article. The connection of the collaborative social context of education with game-based learning is discussed in the first part of the paper. The second part of the paper introduces the game concept of "UniGame: Social Skills and Knowledge Training". Game ideas along the educational background of the UniGame game concept are outlined. UniGame scenarios presented and possible use cases should stimulate users to apply game-based learning approach in the future for their classes.

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DOI: 10.3217/jucs-009-04-0369

Authors: Daniela Camhy, Robert Stubenrauch

Abstract: This bibliography offers citations for people who are interested in learning more about visual language, new types of communicating and archiving information with emphases on novel technologies and theoretical works in these multidisciplinary areas. This bibliography is considered in its broadest sense and covers references of research in humanities and social sciences as well as computer technology. Far from being exhaustive, it nevertheless covers essential resources in a selective way, so that the material can provide starting points for many different directions. What is not included here are references to visual programming languages.

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DOI: 10.3217/jucs-009-04-0349

Authors: Robert Stubenrauch, Daniela Camhy, Jennifer Lennon, Hermann Maurer

Abstract: Systems supporting new forms of communication and archiving of dynamic visual information have a range of potential applications, some of which are described in this paper on a conceptual basis. We present a visual language for dynamic (historic) maps, applications of pictorial lexicons, concepts for interactive support systems for assembly and repair, and a platform for abstract movies.

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DOI: 10.3217/jucs-009-04-0309

Authors: Hermann Maurer, Robert Stubenrauch, Daniela Camhy

Abstract: Research in neurosciences, cognitive psychology and media sciences indicates that "visual thinking" carries a potential of the human mind that is generally still neglected today but could heavily be fostered by novel types of communicating and archiving information. Computer technology (information systems, telecommunication and visual tools) in turn promises to provide a wide range of highly effective tools to support visual, dynamic communication. MIRACLE treads new paths to address a crucial issue: In what way and to what extent can and should current and future systems support new ways of communicating and archiving information using dynamic, visual information? This paper gives a survey of the numerous attempts that have been made so far to overcome language barriers by introducing artificial languages (both on a spoken/text and on a visual basis). It also analyzes the general status of technology (computer hardware and software) to support such efforts as well as a number of specific projects. From this overview we draw the conclusion that computer-based systems designed to support communicating and archiving dynamic visual information should focus on the following features: Support dynamic language elements on a structural level in addition to traditional animated icons, Incorporate gestural language elements (inspired by natural sign languages) anticipating future ways of human-computer interaction, Allow evolutionary development of the language in a group-dynamic and interactive process involving large international groups of participants. In a final section we give a brief outline of the cluster of specific projects carried out under the heading of MIRACLE.

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DOI: 10.3217/jucs-008-06-0644

Authors: Thomas Schwotzer, Kurt Geihs

Abstract: New wireless protocols like W-LAN and Bluetooth allow establishing spontaneous networks and peer-to-peer exchange of information. At the same time standards like Semantic Web and Topic Maps gain acceptance that add semantics to information. This paper introduces Shark. Shark is an acronym and stands for “Mobile Shared Knowledge”. Shark organizes knowledge with help of Topic Maps, synchronizes knowledge inside closed user groups but also enables a peer-to-peer exchange of knowledge by means of Bluetooth. This paper gives an overview of the system and its communication protocols.

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DOI: 10.3217/jucs-008-06-0591

Authors: Lobna Jéribi, Bèatrice Rumpler

Abstract: The main goal of this research is to improve Information Retrieval Systems by enabling them to generate search outcomes that are relevant and customized to each specific user. Our proposal advocates the use of Instance Based Reasoning during the information retrieval process. When conducting a search, the system retrieves a previous similar search experience and traces back previous human reasoning and behavior and then replicates it in the current situation. Thus, user information retrieval experiences or instances are saved to be reused in future similar cases. The resulting cooperative memory is used for user query expansion. In order to improve the information retrieval experience, we propose to conceptualize and model both the user profile, and the information retrieval process. This leads us to define some similarity functions between user profiles and information retrieval situations. The reuse of past experiences serves to enrich the initial user query by words from documents found in similar cases. Unlike the classical Rocchio method, these documents are those already judged as valid by users with similar profile and in similar search situation. The value this method brings to the user is an icreasing relevance of the search outcomes while reducing user interaction with the system. This method has been implemented in the COSYDOR (Cooperative System for Document Retrieval) prototype based on Intermedia (Oracle 8i). Tests and evaluations have been performed on the COSYDOR prototype using the test corpus of TREC (Text Retrieval Converence) and its standard procedures for performance analysis and benchmarking. The results of these analyses show a significant improvement of performance in the first search iterations compared to the Intermedia benchmark.

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DOI: 10.3217/jucs-007-09-0826

Authors: Helge Kahler

Abstract: Tailorability (or adaptability) of software becomes more important with the increasing use of off-the-shelf-software. On the other hand, computers support the work of many groups which in turn have to tailor a commonly used software to support individual as well as group needs. This includes not only groupware, i. e., software that directly supports collaborative work, but also single user software. Research has shown that often adaptations to single user software are distributed among colleagues, thus leading to a systematization in a group's adaptations. Based on this observation an empirical field-study on the collaborative tailoring habits of users of a particular word processor was carried out. Based on these and literature research an add-on to this word processor was developed which provides a public and a private repository for adaptations as well as a mailing function for users to exchange adaptations. Some notification and annotation mechanisms are also provided. Results of two forms of evaluation indicate that users of different levels of qualification are able to handle the tool and consider it a relevant alternative to existing mailing mechanisms.

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DOI: 10.3217/jucs-003-08-0843

Authors: Wolfgang Prinz, Anja Syri

Abstract: This paper describes the realisation of and experiences with two complementary tools for the support of cooperative processes: electronic circulation folders and shared workspaces. Circulation folders support structured work processes, shared workspaces provide a working environment for less structured processes. Both approaches are complementary and their combined usage provides new and very flexible ways of telecooperation and cooperative knowledge management. The components are integrated in the POLITeam system which is developed for the support of cooperative processes between the separated ministries in Bonn and Berlin.

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