DOI: 10.3897/jucs.94067

Authors: Luis P. Prieto, Gerti Pishtari, Yannis Dimitriadis, María Jesús Rodríguez-Triana, Tobias Ley, Paula Odriozola-González

Abstract: Recent advances in machine learning and natural language processing have the potential to transform human activity in many domains. The field of learning analytics has applied these techniques successfully to many areas of education but has not been able to permeate others, such as doctoral education. Indeed, doctoral education remains an under-researched area with widespread problems (high dropout rates, low mental well-being) and lacks technological support beyond very specialized tasks. The inherent uniqueness of the doctoral journey may help explain the lack of generalized solutions (technological or otherwise) to these challenges. We propose a novel approach to apply the aforementioned advances in computation to support doctoral education. Single-case learning analytics defines a process in which doctoral students, researchers, and computational elements collaborate to extract insights about a single (doctoral) learner's experience and learning process. The feasibility and added value of this approach are demonstrated using an authentic dataset collected by nine doctoral students over a period of at least two months. The insights from this exploratory proof-of-concept serve to spark a research agenda for future technological support of doctoral education, which is aligned with recent calls for more human-centred approaches to designing and implementing learning analytics technologies.

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DOI: 10.3897/jucs.2020.059

Authors: Ranjan Behera, Sushree Das, Santanu Rath, Sanjay Misra, Robertas Damasevicius

Abstract: Stock prediction is one of the emerging applications in the field of data science which help the companies to make better decision strategy. Machine learning models play a vital role in the field of prediction. In this paper, we have proposed various machine learning models which predicts the stock price from the real-time streaming data. Streaming data has been a potential source for real-time prediction which deals with continuous ow of data having information from various sources like social networking websites, server logs, mobile phone applications, trading oors etc. We have adopted the distributed platform, Spark to analyze the streaming data collected from two different sources as represented in two case studies in this paper. The first case study is based on stock prediction from the historical data collected from Google finance websites through NodeJs and the second one is based on the sentiment analysis of Twitter collected through Twitter API available in Stanford NLP package. Several researches have been made in developing models for stock prediction based on static data. In this work, an effort has been made to develop scalable, fault tolerant models for stock prediction from the real-time streaming data. The Proposed model is based on a distributed architecture known as Lambda architecture. The extensive comparison is made between actual and predicted output for different machine learning models. Support vector regression is found to have better accuracy as compared to other models. The historical data is considered as a ground truth data for validation.

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DOI: 10.3897/jucs.2020.031

Authors: Rastko Martać, Nikola Milivojević, Marijana Despotović-Zrakić, Zorica Bogdanović, Dusan Barać

Abstract: This paper investigates how to transform a manual monitoring system into a smart environment using IoT technologies. Large dams are of huge importance as water reservoirs and potential energy sources primarily because of their use for electric energy generation. Monitoring and predicting dams' behavior are quite challenging. Due to a variety of limitations, environmental obstacles and dam system complexity, the application of RFID, Bluetooth, and IoT technologies has proven to be an adequate, affordable and reliable dam safety solution. This paper introduces a comprehensive model of dam safety management and monitoring based on pervasive technologies. The model described in this work has been applied within the large dam "Iron Gate 1", on the river Danube in the Republic of Serbia. The results show that the use of new technologies in the dam monitoring process can reduce human error and improve overall process.

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DOI: 10.3897/jucs.2020.023

Authors: Milan Sečujski, Darko Pekar, Siniša Suzić, Anton Smirnov, Tijana Nosek

Abstract: The paper presents a novel architecture and method for training neural networks to produce synthesized speech in a particular voice and speaking style, based on a small quantity of target speaker/style training data. The method is based on neural network embedding, i.e. mapping of discrete variables into continuous vectors in a low-dimensional space, which has been shown to be a very successful universal deep learning technique. In this particular case, different speaker/style combinations are mapped into different points in a low-dimensional space, which enables the network to capture the similarities and differences between speakers and speaking styles more efficiently. The initial model from which speaker/style adaptation was carried out was a multi-speaker/multi-style model based on 8.5 hours of American English speech data which corresponds to 16 different speaker/style combinations. The results of the experiments show that both versions of the obtained system, one using 10 minutes and the other as little as 30 seconds of target data, outperform the state of the art in parametric speaker/style-dependent speech synthesis. This opens a wide range of application of speaker/style dependent speech synthesis based on small quantities of training data, in domains ranging from customer interaction in call centers to robot-assisted medical therapy.

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DOI: 10.3897/jucs.2020.021

Authors: Thi Ngoc Trang Tran, Muesluem Atas, Man Le, Ralph Samer, Martin Stettinger

Abstract: Explanations are integrated into recommender systems to give users an insight into the recommendation generation process. Compared to single-user recommender systems, explanations in group recommender systems have further goals. Examples thereof are fairness, which helps to take into account as much as possible group members' preferences and consensus, which persuades group members to agree on a decision. In this paper, we proposed different types of explanations and found the most effective ones in terms of increasing the fairness perception, consensus perception and satisfaction of group members with regard to group recommendations. We conducted a user study to evaluate the proposed explanations. The results show that explanations which consider the preferences of all or the majority of group members achieve the best results in terms of the mentioned dimensions. Besides, we discovered positive correlations among these aspects. In the context of repeated decisions, group members' satisfaction from previous decisions are helpful to improve the fairness perception of users concerning group recommendations and speed up the group decision-making process. Furthermore, we found out that gender diversity does influence the perception of users regarding the mentioned dimensions of the explanations. Although the proposed explanations were analyzed in group decision scenarios for non-configurable (no-attribute) items, there exist potential possibilities to apply them to explanations for configurable items.

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DOI: 10.3217/jucs-025-13-1717

Authors: Andreas Hinderks, Dominique Winter, Martin Schrepp, Jörg Thomaschewski

Abstract: To be successful, interactive products need to fulfil user expectations and create a positive user experience (UX). An established method to measure UX involves questionnaires. What we aim in this paper is to present a list of user experience and United States of Americability questionnaires and its applicability for different digital products. A total of 13 questionnaires on United States of Americability and UX were analysed for this paper, and 25 factors were extracted from those questionnaires. A study was conducted based on this collection of factors with N=61 students. The study investigated the perceived importance of United States of Americability and UX factors for seven digital products. The goal was to have a collection of United States of Americability and UX factors that could be combined for suitable products evaluation. The results of the study revealed that no questionnaire covered all the factors perceived important by the participants.

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DOI: 10.3217/jucs-025-12-1625

Authors: Carlos De Carvalho, Pedro Cano, José Roa, Anna Wanka, Franz Kolland

Abstract: Being able to effectively use online tools has become a fundamental competence in our Society. Therefore, it is important to tackle the age digital divide as there is a rapidly growing number of elderly people. Like everyone else, older adults (senior citizens or the silver generation) must be equipped with the necessary skills to be able to be connected and integrated in the online world to prevent their social isolation and to foster their inclusion. As a contribution to that effort, a European-wide digital literacy development initiative for senior citizens was setup and this article presents the analysis of the achieved results which shows a very positive perception of the seniors on the developed digital abilities.

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DOI: 10.3217/jucs-025-08-0967

Authors: Benjamin Weyers, Ekaterina Auer, Wolfram Luther

Abstract: We suggest to widen the focus of the scientific computations community from an isolated consideration of reliable numerical algorithms using standardized arithmetic to a broad user-centered system modeling and simulation approach relying on an appropriate verification and validation (V&V) design. Most V&V works rarely consider human-related issues specifically. However, modern applications generate and employ huge amounts of heterogeneous data and usually exhibit high complexity - challenges that are best tackled by augmenting human reasoning with automated techniques. That is, novel visual and collaborative approaches are needed to interpret the results, which has to be accounted for in the general V&V procedure. This should include an assessment of (meta-) data and code/outcome quality, selection of methods to propagate and bound uncertainty and, lastly, formally rigorous validation efforts. We present an approach to reliable visual analytics (i.e., analytics subjected to this V&V assessment), which can in turn contribute to the overall V&V procedure after that. Two use cases illustrate the potential of the introduced framework for reliable visual analytics.

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DOI: 10.3217/jucs-024-02-0192

Authors: William Guest, Fridolin Wild, Alla Vovk, Paul Lefrere, Roland Klemke, Mikhail Fominykh, Timo Kuula

Abstract: Leveraging Augmented Reality and wearable technology for knowledge-intensive training is thought to offer huge potential for improving human performance. The recent introduction of the technology means that much of this potential is untapped, though efforts are needed to understand what makes it useful, entertaining, and easy-to-use. The research presented in this article investigates the implementation of a combined hardware and software application in three use-cases: aviation, medical and space. Following the validation of metrics for a questionnaire, data was collected from 142 participants, and a structural equation model, based on UTAUT2, was proposed in order to interpret the data. Following model improvement, two constructs show significant factor loading and latent variable correlation, Interoperability and Augmented Reality / Wearable Technology Fit. Model optimisation was conducted, and a variety of goodness-of-fit indices are reported. The two additional constructs are found to be covariant and impact the UTAUT2 variables performance expectancy, effort expectancy and facilitating conditions, in some cases explaining more than 85% of the variance in those constructs (p < 0.001). A root mean square error of approximation of 0.047 after a 1000-fold Monte Carlo cross-validation indicates a good fit between the model and the data. In all other fit indices, a moderate power has been observed.

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DOI: 10.3217/jucs-024-02-0171

Authors: Samah Felemban, Michael Gardner, Victor Callaghan, Anasol Pena-Rios

Abstract: 3-D virtual worlds and other immersive environments offer features that other learning systems cannot easily replicate. As such, they have the potential to revolutionise the way in which people learn. They are well suited to visualise 3-D objects and their relations to explain complex phenomena. In addition, they enable practical experiments to be performed that are difficult to conduct in the real world. They can also help to facilitate collaborative learning in real-time and enable students to become fully engaged in what they are doing. However, these environments require further exploration to improve their learning affordances. For instance, assessing students' performance and collecting learning evidence is still in its early stages. This paper is primarily devoted to furthering our understanding of observation and assessment. In so doing, a virtual observation model has been developed to effectively map classroom-based observations with how people can be evaluated in virtual 3-D environments. The observation model has been applied to a multi-user virtual environment (MUVE) and examples that illustrate its potential effectiveness are provided. In essence, our research aims to support and enhance the learning experience by demonstrating the advantages of 3-D virtual worlds as a means for advancing learning processes.

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DOI: 10.3217/jucs-024-02-0072

Authors: Max North, Sarah North

Abstract: The primary objective of this concise collection is to explore the sense of presence that participants experience in Virtual Reality Therapy experiments. In this article, sense of presence is briefly defined, followed by a discussion of factors effecting sense of presence, continuing with methods to measure sense of presence and assertions concerning virtual presence, and finally, conclusions and discussions are presented.

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DOI: 10.3217/jucs-023-07-0636

Authors: Gaoshan Deng, Quanxi Feng, Pan Zheng, Tao Song

Abstract: Heterogeneous computing systems (HCSs) use many heterogeneous processors or cores to perform particular tasks. To address the requirement of green IT, several power management techniques have been developed to reduce the energy consumption of these systems. Dynamic voltage scaling, which dynamically changes the supply voltage of processors during the execution of an application, is widely used. However, reducing supply voltage decreases computation speed. Therefore, system makespan and energy consumption need to be considered at the same time. We propose a multi-objective scheduling algorithm based on decomposition for scheduling of the system workflow. Through experiments, we examine the performances of several algorithms, including the proposed one, in different benchmarks and real-world applications. Results show that our algorithm demonstrates better performance than other state-of-art evolutionary algorithms under various conditions involving the use of different crossover and mutation operators.

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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-021-01-0048

Authors: Alan Dix, Justin Leavesley

Abstract: If learning analytics are to directly benefit students' learning rather than simply inform broad policy decisions, they must be used by academics in the midst of busy and fragmented lives. This paper takes an ecological or action-oriented perspective of the use of learning analytics in higher education, drawing on research sources in psychology, human-computer interaction and visual analytics. We unpack the circumstances during the learning interactions of academics with course materials and students where analytics could trigger or influence action. This leads to a framework based around different academic timescales, and the strategies for synchronising the recognition of need with the potential for execution of teaching and learning interventions.

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DOI: 10.3217/jucs-020-06-0826

Authors: Maral Mayeh, Thurasamy Ramayah, Simona Popa

Abstract: The purpose of this study is to model the relationship between absorptive capacity and intention to use in the Enterprise Resource Planning (ERP) environment in Iran. This research is a correlation study where a field survey was employed for data collection. The unit of analysis is Iranian individuals who are ERP user in organizations using ERP systems. The questionnaires were sent to the selected organizations. Using a structural equation modeling analysis we tested the hypothesized relationship using AMOS version 16.0. The results indicate that all three absorptive capacity measures to be good predictors of intention to use. Absorptive capacity for applying was the strongest predictor followed by absorptive capacity for understanding and absorptive capacity for assimilating. When implementing complex information systems, managers must also look at the absorptive capacity of the users in order to successful implementation of the system and to ensure continued usage. Previous researchers have not looked at the role of absorptive capacity in system usage at the same rate as those related to technology acceptance research which only focuses on the ease of use and usefulness. Thus this research adds on to the existing literature where future researchers may want to expand on the factors that may influence absorptive capacity for further policy implications.

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DOI: 10.3217/jucs-019-17-2598

Authors: Juan Mateu, Xavier Alamán

Abstract: Nowadays, one of the hot issues in the agenda is, undoubtedly, the concept of Sustainable Computing. There are several technologies in the intersection of Sustainable Computing and Ambient Intelligence. Among them we may mention "Human-Centric Interfaces for Ambient Intelligence" and "Collaborative Smart Objects" technologies. In this paper we present our efforts in developing these technologies for "Mixed Reality", a paradigm where Virtual Reality and Ambient Intelligence meet. Cubica is a mixed reality educational application that integrates virtual worlds with tangible interfaces. The application is focused on teaching computer science, in particular "sorting algorithms". The tangible interface is used to simplify the abstract concept of array, while the virtual world is used for delivering explanations. This educational application has been tested with students at different educational levels in secondary education, having obtained promising results in terms of increased motivation for learning and better understanding of abstract concepts.

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DOI: 10.3217/jucs-019-17-2577

Authors: George Okeyo, Liming Chen, Hui Wang

Abstract: Activity recognition enables ambient assisted living applications to provide activity-aware services to users in smart homes. Despite significant progress being made in activity recognition research, the focus has been on simple activity recognition leaving composite activity recognition an open problem. For instance, knowledge-driven activity recognition has recently attracted increasing attention but mainly focused on simple activities. This paper extends previous work by introducing a knowledge-driven approach to recognition of composite activities such as interleaved and concurrent activities. The approach combines the recognition of single and composite activities into a unified framework. To support composite activity modelling, it combines ontological and temporal knowledge modelling formalisms. In addition, it exploits ontological reasoning for simple activity recognition and qualitative temporal inference to support composite activity recognition. The approach is organized as a multi-agent system to enable multiple activities to be simultaneously monitored and tracked. The presented approach has been implemented in a prototype system and evaluated in a number of experiments. The experimental results have shown that average recognition accuracy for composite activities is 88.26%.

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DOI: 10.3217/jucs-019-17-2543

Authors: Jaime Caffarel, Song Jie, Jorge Olloqui, Rocío Martínez, Asunción Santamaría

Abstract: This paper presents an Ontology-Based multi-technology platform designed to avoid some issues of Building Automation Systems. The platform allows the integration of several building automation protocols, eases the development and implementation of different kinds of services and allows sharing information related to the infrastructure and facilities within a building. The system has been implemented and tested in the Energy Efficiency Research Facility at CeDInt-UPM.

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DOI: 10.3217/jucs-019-17-2526

Authors: Constantin Taivan, Rui José, Bruno Silva, Ivan Elhart, Jorge Cardoso

Abstract: Urban spaces are increasingly embedded with various types of public digital displays. Many of these displays can be subject to multi-user interactions and support a broad range of applications. A fundamental implication emerging from the interactive nature of those applications is that users should have access to appropriate selection and control techniques that would allow them to drive the way applications are shown and used in the respective environment. Such techniques should enable each user to reason and express intentions about the system behavior, while also dealing with concurrent requests from multiple users in a way that is fair and clear. In this study, we aim to inform the definition of novel techniques for application selection and control in pervasive display environments that can address the above challenges. Drawing inspiration from traditional GUI interaction concepts we developed and deployed a public display system that supports multiple applications and is able to receive explicit content presentation requests from multiple viewers. Based on the experiment observations and interviews with the participants, we reached a set of design considerations for future pervasive displays environments that are open to third party applications providers and allow the audience to influence content presentation.

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DOI: 10.3217/jucs-019-17-2503

Authors: Ana Bernardos, Luca Bergesio, Josue Iglesias, José Casar

Abstract: In this paper, we exploit the capabilities of mobile devices as instruments to facilitate interaction in spaces populated with smart objects. We do this through MECCANO, a framework that supports an interaction method for a user to perform physical discovery and versatile configuration of behaviors involving a network of smart objects. Additionally, MECCANO guides the developer to easily integrate new augmented objects in the smart ecosystem. Behaviors are rule-based micro-services composed by a combination of events, conditions and actions that one or more smart objects can trigger, detect or perform. Each object owns and publishes its capabilities in a software module; this module becomes available when a user physically lies in the area of influence of the smart object. The capabilities provided by a specific object can be merged with those in other objects (including those in the user's mobile device itself) to configure a behavior involving several objects, adapted to the user's needs. On operation, the behavior is run within the mobile device, serving the device as orchestrator of the involved objects. The framework also facilitates sharing micro-services in such a way that users can act as prosumers by generating their self-made behaviors. New behaviors are associated to the classes of objects that are needed to execute them, becoming ready for other users to download. The proposed interaction method and its tools are demonstrated both from the developer's and the end-user's points of view, through practical implementations.

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DOI: 10.3217/jucs-019-15-2320

Authors: Karol Rástočný, Michal Tvarožek, Maria Bielikova

Abstract: Information seeking on the Web has become day-to-day routine for more than two billion human beings most of who use traditional keyword-based search engines. Developers of these search engines stress personalization, prediction of users' next actions and mistake correction. But they are still struggling with results presentation and support for users, who make atypical queries or who do not exactly know what they are looking for. We address these issues via a novel approach for exploring web repositories, which naturally combines user search activities - look up, learning and investigation. We achieve this via view-based navigation in hierarchical clusters and two-dimensional graphs of search results.

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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-019-15-2266

Authors: Javier Marco, Sandra Baldassarri, Eva Cerezo

Abstract: In this paper, the design process of a tangible game for a tabletop device (NIKVision) is presented. NIKVision is intended to give leisure and fun while reinforcing physical manipulation and co-located gaming for 3-6 year old children. Interaction is provided by the handling of conventional toys and computer augmentation on a table surface. The presence of an additional vertical monitor that complements table surface output is a distinguishing feature of NIKVision. By following a engineering design lifecycle, the paper describes the complete process of designing a Farm Game for the tabletop. Children have been involved, for the very starting point, through continuous test sessions in schools and nurseries. The data recovered from these sessions have been essential, not only to detect problems, but to take the more adequate design decisions. Different children-centred design methods have been used, depending on the question to be evaluated or designed, ranging from observation notes to Wizard of Oz, or video-analysis. The paper exposes the results of a final summative evaluation that summarizes the performance of the game in relation to Usability, User Experience and physical and co-located gaming. The experience obtained by the authors from this process has crystalized in a set of reflections about the feasibility of designing with very young children and about the value of the data obtained from them.

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DOI: 10.3217/jucs-019-13-2013

Authors: Antonio Cabanas-Abascal, Eduardo García-Machicado, Lisardo Prieto-González, Antonio Seco

Abstract: Nowadays, one of the most relevant features provided by in almost every web site is a recommender system. However, they are usually focused on the common characteristics of several items which are shared among the users without taking into account that there are other very important features, such as geo-position. To face this lack of such relevant factors, authors propose the usage of a useful system that will aid in tasks related to pattern detection and fast adaptability to changes: Artificial Immune System. A combination of both systems and the addition of a geographic component will provide a new solution to this problem, which will solve as well these issues as other ones like comparison tasks in big data.

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DOI: 10.3217/jucs-019-12-1792

Authors: Pedro Villanueva, Ricardo Tesoriero, José A. Gallud Lázaro, Abdulrahman Altalhi

Abstract: The pervasiveness of the Web, and the emergence of new technologies such as the RFID, allow users to interact with the physical environment. This fact has caused the conception of new types of applications, for instance, the Web applications based on RFID panels that allow users to retrieve and store resources from and to the Web through RFID panels. The development of these applications is defined by three main concepts: the Tool that performs domain model functionality, the Command that represents an action to be performed by the tool, and finally, the Resource representing the result of the command on the tool. Thus, this work presents a framework that enables developers to model Web applications based on RFID panels in terms of these concepts. The paper also exposes how to extend the framework to build four applications that belong to absolutely different domains.

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DOI: 10.3217/jucs-019-09-1295

Authors: Davide Anguita, Alessandro Ghio, Luca Oneto, Xavier Parra, Jorge Reyes-Ortiz

Abstract: In this paper we propose a novel energy efficient approach for the recog-nition of human activities using smartphones as wearable sensing devices, targeting assisted living applications such as remote patient activity monitoring for the disabledand the elderly. The method exploits fixed-point arithmetic to propose a modified multiclass Support Vector Machine (SVM) learning algorithm, allowing to better pre-serve the smartphone battery lifetime with respect to the conventional floating-point based formulation while maintaining comparable system accuracy levels. Experimentsshow comparative results between this approach and the traditional SVM in terms of recognition performance and battery consumption, highlighting the advantages of theproposed method.

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DOI: 10.3217/jucs-019-03-0383

Authors: Christin Seifert, Eva Ulbrich, Roman Kern, Michael Granitzer

Abstract: In text classification the amount and quality of training data is crucial for the performance of the classifier. The generation of training data is done by human labellers - a tedious and time-consuming work. To reduce the labelling time for single documents we propose to use condensed representations of text documents instead of the full-text document. These condensed representations are key sentences and key phrases and can be generated in a fully unsupervised way. We extended and evaluated the TextRank algorithm to automatically extract key sentences and key phrases. For representing key phrases we propose a layout similar to a tag cloud. In a user study with 37 participants we evaluated whether document labelling with these condensed representations can be done faster and equally accurate by the human labellers. Our evaluation shows that the users labelled tag clouds twice as fast and as accurately as full-text documents. While further investigations for different classification tasks are necessary, this insight could potentially reduce costs for the labelling process of text documents.

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DOI: 10.3217/jucs-018-11-1432

Authors: David Griffiths, Mark Johnson, Kris Popat, Paul Sharples, Scott Wilson

Abstract: Apache Wookie (incubating) has generated considerable interest within the context of Technology Enhanced Learning where it was developed, as well as in mobile applications. The origins of the system in providing services for IMS Learning Design are described, together with an introduction to the system's design and functionality. However, the areas where it has had success are distinct from the application area for which it was designed and developed. The implications of this for understanding user needs is analysed by using ideas drawn from sociology. The complexity of the relationship between the context of use and user needs, and the feedback loops between them is discussed, and the role of technological interventions as an element in a discourse is considered. It is proposed that this understanding of users needs, together with the experience of the development and use of Wookie, argues in favour of an interoperability strategy which focuses on relatively small sets of functional requirements, and avoidance where possible of specifications developed for particular application domains: an approach which may be characterised as piecemeal rather than Utopian.

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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-018-01-0062

Authors: Jesus Boticario, Alejandro Rodriguez-Ascaso, Olga Santos, Emmanuelle Raffenne, Lydia Montandon, David Roldán, Félix Buendía

Abstract: The EU4ALL project (IST-FP6-034778) has developed a general framework to address the needs of accessible lifelong learning at Higher Education level consisting of several standards-based interoperable components integrated into an open web service architecture aimed at supporting adapted interaction to guarantee students' accessibility needs. Its flexibility has supported the project implementation at several sites with different settings and various learning management systems. Large-scale evaluations involving hundreds of users, considering diverse disability types, and key staff roles have allowed obtaining valuable lessons with respect to "how to adopt or enhance eLearning accessibility" at university. The project was evaluated at four higher education institutions, two of the largest in Europe and two medium-sized. In this paper, we focus on describing the implementation and main conclusions at the largest project evaluation site (UNED), which was involved in the project from the beginning, and thus, in the design process, and a medium-sized university that adopted the EU4ALL approach (UPV). This implies dealing with two well-known open source learning environments (i.e. dotLRN and Sakai), and considering a wide variety of stakeholders and requirements. Thus the results of this evaluation serve to illustrate the coverage of both the approach and developments.

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DOI: 10.3217/jucs-017-14-1931

Authors: Ana Cristina B. Garcia, Adriana Vivacqua, Thiago Tavares

Abstract: Democratic governments constantly need to make sense of their citizens' needs to make appropriate decisions that reflect the overall wishes and needs of the population. However, except for mandatory voting scenarios, a low rate of citizen participation in government decisions through democratic processes is an aspect that defies democracy itself. Brazil's participatory budget policy emphasizes people's direct guidance regarding certain budget allocations though group meetings. This paper presents mParticipation, an agent-based model for eliciting and answering citizen demands in a participatory government structure using mobile technology. A prototype system applied to the domain of public budget allocation domain demonstrates that it is feasible to provide effective computational support to participatory collective decision-making.

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DOI: 10.3217/jucs-017-12-1659

Authors: Rory Sie, Marlies Bitter-Rijpkema, Peter Sloep

Abstract: Several studies have shown that connecting to people in other networks foster creativity and innovation. However, it is often difficult to tell what the prospective value of such alliances is. Cooperative game theory offers an a priori estimation of the value of future collaborations. We present an agent-based social simulation approach to recommending valuable peers in networked innovation. Results indicate that power as such does not lead to a winning coalition in networked innovation. The recommendation proved to be successful for low-strength agents, which connected to high-strength agents in their network. Future work includes tests in real-life and other recommendation strategies.

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DOI: 10.3217/jucs-017-10-1511

Authors: Benedikt Schmidt, Todor Stoitsev, Max Mühlhäuser

Abstract: Intention-aware systems integrate aspects of context-aware and attentionaware systems for the identification and support of intention. Focusing intention is justified by the impact of intention on awareness and interaction with the world. Therefore, proactive user support mechanisms can be improved by including a representation of intention. In this paper, the externalization of intention in task models is discussed: existing task models are reviewed and activity schemes are proposed as task model for intention-aware systems. A framework for intention-aware systems is presented and discussed in detail.

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DOI: 10.3217/jucs-017-07-1078

Authors: Syed Shahzad

Abstract: The user experience of any software or website consists of elements from the conceptual to the concrete level. These elements of user experience assist in the design and development of user interfaces. On the other hand, ontologies provide a framework for computable representation of user interface elements and underlying data. This paper discusses strategies of introducing ontologies at different user interface layers adapted from user experience elements. These layers range from abstract levels (e.g. User needs/Application Objectives) to concrete levels (e.g. Application User Interface) in terms of data representation. The proposed ontological framework enables device independent, semi-automated GUI construction which we will demonstrate at a personal information management example.

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DOI: 10.3217/jucs-017-02-0296

Authors: Jianming Yong

Abstract: This paper systematically discusses the security and privacy concerns for e-learning systems. A five-layer architecture of e-learning system is proposed. The security and privacy concerns are addressed respectively for five layers. This paper further examines the relationship among the security and privacy policy, the available security and privacy technology, and the degree of e-learning privacy and security. The digital identity attributes are introduced to e-learning portable devices to enhance the security and privacy of e-learning systems. This will provide significant contributions to the knowledge of e-learning security and privacy research communities and will generate more research interests.

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DOI: 10.3217/jucs-017-02-0164

Authors: Claudio Sapateiro, Nelson Baloian, Pedro Antunes, Gustavo Zurita

Abstract: We describe the design of a mobile collaborative tool that helps teams managing critical computing infrastructures in organizations, a task that is usually designated Business Continuity Management. The design process started with a requirements definition phase based on interviews with professional teams. The elicited requirements highlight four main concerns: collaboration support, knowledge management, team performance, and situation awareness. Based on these concerns, we developed a data model and tool supporting the collaborative update of Situation Matrixes. The matrixes aim to provide an integrated view of the operational and contextual conditions that frame critical events and inform the operators’ responses to events. The paper provides results from our preliminary experiments with Situation Matrixes.

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DOI: 10.3217/jucs-016-16-2232

Authors: Jinhyuk Choi, Geehyuk Lee, Junghoon Moon

Abstract: The fact that the World Wide Web is being used for various purposes also implies that users may have various information quality factors to consider according to their current context. In this regards, it is important for Web recommendation services to recognize what quality factors should be considered in current context in order to enhance user satisfaction. We showed that it is necessary to classify Web contexts based on the information quality factors users consider in their minds when they choose websites or Web pages. The results of user interviews showed that there are four quality factors: credibility, recency, popularity, and relevance. From survey data analysis, we recognized that user tasks can be clustered into two groups based on the quality factors that users consider. Finally, the results of log data analysis and performances of our proposed algorithm showed that it is possible to enable Web services to infer the context group. This result implies that context recognition is possible using the limited data that are collected at browser side.

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DOI: 10.3217/jucs-016-13-1801

Authors: Chulmo Koo, Yulia Wati

Abstract: Mobile banking has been considered to be one of the most value-added and important mobile services currently available. Considering the fact that the penetration of this technology is undefined well, particularly in developing country, this study clarified the role of trust as a mediating variable in mobile banking environment. An empirical study was undertaken in Indonesia and the data of 100 respondents were collected. The empirical results provided strong evidence for the explanatory power of our research model. Firstly, we found that the trust mediated the effects of information quality to perceived usefulness and end-user satisfaction. Second, the both relationships of system quality and perceived usefulness and system quality and end-user satisfaction were partially mediated by trust. Third, trust also showed a direct effect on both end-user satisfaction and perceived usefulness. Lastly, the result provided support of the positive relationship between perceived usefulness and end-user satisfaction. Implication for both practice and further research were also discussed.

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DOI: 10.3217/jucs-016-12-1633

Authors: Manuel García-Herranz, Pablo Haya, Xavier Alamán

Abstract: This article presents a rule-based agent mechanism as the kernel of a ubiquitous end-user, UI–independent programming system. The underlying goal of our work is to allow end–users to control and program their environments in a uniform, application-independent way. The heterogeneity of environments, users and programming skills, as well as the coexistence of different users and domains of automation in the same environment are some of the main challenges analyzed. For doing so, we present our system and describe some of the real–environments, user studies and experiences we have had in the development process.

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DOI: 10.3217/jucs-016-12-1577

Authors: Gabriel Chavira, José Bravo, Salvador Nava-Díaz, Julio Rolón

Abstract: A natural interface is one of three key technologies of Ambient Intelligence (AmI); one of its main objectives is to minimize the user's interactive effort, which is the difficulty level that depends on the diversity and quantity of devices that surround people in existing environments. The worldwide penetration of mobile phones at present makes mobile phones excellent devices for delivering new services to users without requiring learning effort. An NFC-enabled mobile phone will allow a user to demand and obtain services by touching its different elements in a given smart environment. In this paper, we present a proposal in which we analyze the scope of touch interaction and develop a perceived touch interaction through tagging context (PICTAC) model.

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DOI: 10.3217/jucs-016-12-1480

Authors: Rui José, Helena Rodrigues, Nuno Otero

Abstract: Ambient Intelligence (AmI) has emerged in the past 10 years as a multidisciplinary field within ubiquitous computing, attracting considerable research, funding and public attention and leading to many research groups, and conferences specifically focused on Ambient Intelligence topics. From its conception, AmI has always been a field strongly driven by a particular vision of how ICT technologies would shape our future. This has given the AmI vision, essentially as proposed by ISTAG, an excessively central role in shaping the field and setting its research agenda. We argue that this inspiring vision should no longer be the main driver for AmI research and that we should now re-interpret its role in the background of 10 years of research. In this paper, we reflect on what it means for AmI to move behind its foundational vision and we identify a number of emerging trends around some of its core concepts, more specifically the notion of intelligence, the system view and the requirements process. The main motivation is to search for alternative research directions that may be more effective in delivering today the essence of the AmI vision, even if they mean abandoning some of the currently prevailing approaches and assumptions. Overall, these trends provide a more holistic view of AmI and may represent important contributions for bringing this field closer to realisation, delivery and real social impact.

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DOI: 10.3217/jucs-016-07-1036

Authors: Monika Lanzenberger, Jennifer Sampson, Markus Rester

Abstract: Ontologies are used to represent a variety of domain knowledge and data collections, scopes, viewpoints and linked heterogeneous information sources. They range from simple topologies to highly structured knowledge bases with complex relations. When mapping or aligning two or more ontologies an efficient user support is needed so that the users can understand the prerequisites and the consequences of the alignments. Information Visualization techniques can help to facilitate user understanding of the ontology alignment results. In general, a lot of work in visualization of ontologies exist. We found an enormous number of ontology visualization tools by a literature study. Many of them apply graph visualization but there are other approaches as well. We have identified interesting solutions for dealing with the complexity of large ontologies. Ontology engineering, ontology mapping and alignment can benefit from Information Visualization. Our collection is a starting point to demonstrate the usefulness of Information Visualization techniques, however, a detailed evaluation would be the next step to consolidate this research area and help to boost the adoption of ontologies in common Web applications.

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DOI: 10.3217/jucs-016-07-1006

Authors: Grzegorz Nalepa

Abstract: In the paper application of semantic wikis as knowledge engineering toolin a collaborative environment is considered. Selected aspects of semantic wikis are discussed. The main apparent limitation of existing semantic wikis is the lack of expressiveknowledge representation mechanism. Building a knowledge base with a semantic wiki becomes complicated because of its collective nature, where number of users collaboratein the knowledge engineering process. A need for knowledge evaluation and analysis facilities become clear. The paper discusses a new semantic wiki architecture calledPlWiki. The most important concept is to provide a strong knowledge representation and reasoning with Horn clauses-based representation. The idea is to use Prolog clauseson the lower level to represent facts and relations, as well as define rules on top of them. On the other hand a higher-level Semantic Web layer using RDF support is provided.This allows for compatibility with Semantic Media Wiki while offering improved representation and reasoning capabilities. Another important idea is provide an extension toalready available flexible wiki solution (DokuWiki) instead of modifying existing wiki engine. Using the presented architecture it is possible to analyze rule-based knowledgestored in the wiki.

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DOI: 10.3217/jucs-016-01-0178

Authors: Grzegorz Kolaczek, Krzysztof Juszczyszyn

Abstract: In this paper we consider a multiagent system with multiple ontologies. The agents maintain the ontologies individually which leads to frequent changes and possible knowledge inconsistencies. We propose a general framework for decision making about ontology alignment and negotiation which takes into account the properties of the actual communication network and utilizes the Deontic Logic formalism for reasoning.

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DOI: 10.3217/jucs-015-13-2446

Authors: Dunwei Gong, Xin Yao, Jie Yuan

Abstract: Interactive genetic algorithms (IGAs) are effective methods to solve optimization problems with implicit or fuzzy indices. But human fatigue problem, resulting from evaluation on individuals and assignment of their fitness, is very important and hard to solve in IGAs. Aiming at solving the above problem, an interactive genetic algorithm with an individual fitness not assigned by human is proposed in this paper. Instead of assigning an individual fitness directly, we record time to choose an individual from a population as a satisfactory or unsatisfactory one according to sensitiveness to it, and its fitness is automatically calculated by a transformation from time space to fitness space. Then subsequent genetic operation is performed based on this fitness, and offspring is generated. We apply this algorithm to fashion design, and the experimental results validate its efficiency.

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DOI: 10.3217/jucs-015-09-1991

Authors: Emerson Paraiso, Cesar Tacla

Abstract: We have been using personal assistants (PA) coupled with multi-agent systems (MASs) in several CSCW applications. Since we are considering professional environments, where users have many tasks to perform, and where users are using several different applications at the same time (browsers, CADs, etc.), the PA interface should motivate users to keep using their assistant. To achieve this goal, we propose WebAnima. WebAnima is a web-based embodied interface agent specially designed to assist team members of a CSCW application during their daily work based on computers. In WebAnima, the intelligent behaviour is guaranteed thanks to a conversational interface and ontologies that support semantic interpretation. We believe that embodied conversational assistants will improve the quality of assistance and increase collaboration between project members. With WebAnima, we expect to acquire information that can be further processed and reused in current and subsequent projects aiming at increasing productivity. In this paper, we present the embodied conversational assistant and its insertion into an MAS designed for research and development projects. We describe the design of the agent, highlighting the role of ontologies for semantic interpretation and the dynamic behaviour of the embodied animated agent.

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DOI: 10.3217/jucs-014-19-3202

Authors: Chi Tran, Houcine Ezzedine, Christophe Kolski

Abstract: The evaluation of interactive systems has been an active subject of research for many years. Many methods and tools have been proposed but most of them do not take architectural specificities of agent-based interactive systems into account. In addition, electronic informers are popular evaluation tools but current ones have often some limits. In order to solve these problems, we propose an electronic informer to evaluate agent-based interactive systems. This tool captures interaction events occurred in agent-based interactive systems and then, based on such captured data, it realizes treatments such as calculations, statistics and generates Petri Nets (PNs) to assist evaluators in evaluating three aspects of the system: user interface, non-functional properties (e.g. response time, reliability, etc.) and user’s properties (e.g. abilities, preferences, etc.). The approach has been validated by applying it to evaluate an agent-based interactive system used for the supervision of urban transport network.

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DOI: 10.3217/jucs-014-19-3114

Authors: Jesús Ibáñez, David García, Oscar Serrano

Abstract: This paper presents Musimage, a novel system which displays pictures according to the songs being played at the same time. By using the interface the user selects the songs to be played, but the pictures are automatically selected. For each song to be played, the system selects a set of pictures, according to various criteria corresponding to some features of the song. In this sense, the pictures to be shown are, metaphorically, triggered by the songs.

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DOI: 10.3217/jucs-014-16-2720

Authors: Gitte Lindgaard, Catherine Pyper, Monique Frize, Robin Walker, Craig Boutilier, Bowen Hui, Sheila Narasimhan, Janette Folkens, Bill Winogron, Peter Egan, Colin Jones

Abstract: Decision Support Systems are proliferating rapidly in many areas of human endeavour including clinical medicine and psychology. While these are typically based on rule-based systems, decision trees, or Artificial Neural Networks, this paper argues that Bayes’ Theorem can be applied fruitfully to support expert decisions both in dynamically changing situations requiring the system progressively to adapt, and when this is not the case. One example of each of these two types is given. One provides diagnostic support for human decision makers; the other, an e-health mental intervention system provides decision rules enabling it to respond and provide the most appropriate training modules to input from clients with changing needs. The contributions of psychological research underlying both systems is summarized.

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DOI: 10.3217/jucs-014-16-2650

Authors: Judy Van Biljon, Paula Kotzé

Abstract: In human-computer interaction and computing, mobile phone usage is mostly addressed from a feature-driven perspective, i.e. which features do a certain user group use, and/or a usability perspective, i.e. how do they interact with these features. Although the feature driven and usability focus carry value, it is not the full picture. There is also an alternative or wider perspective: mobile phone use is influenced by demographic, social, cultural, and contextual factors that complicate the understanding of mobile phone usage. Drawing on concepts and models from sociology, computer-supported cooperative work, human-computer interaction and marketing, we researched the influence of culture on mobile phone adoption using interviews and two surveys. The contribution of this research is a model that includes culture as one of the factors that influence mobile phone adoption and usage. The proposed model represents the influence of mediating factors and determining factors on actual mobile phone use. The proposed model has been evaluated from both a qualitative and quantitative perspective.

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DOI: 10.3217/jucs-014-16-2630

Authors: José Cañas

Abstract: Cognitive Ergonomics is a discipline that contributes with its knowledge to construct better machines in the sense of being easier to use by human beings. Cognitive Ergonomists perform a cognitive analysis of interaction to: (1) shorten the time to accomplish interaction tasks; (2) reduce the number of mistakes made by humans; (3) reduce learning time; and (4) improve people’s satisfaction with a system. An appropriate methodology for performing this cognitive analysis of interaction could be based on what I call the "Principle of Mutual Dependency" [Cañas et al 2004]. This principle determines that: (1) The optimal interface functions will be those that fit the human cognitive functions involved in the task; (2) The human cognitive functions that are involved in the task depend on the interface functions; (3) The modification, replacement, or introduction of a new interface function implies the adaptation of the human cognitive functions; (4) The development (e.g., learning) or limitation (e.g., Elderly users) of the human cognitive functions will imply limitations on the possible interface functions. I will describe this principle with examples from research projects in which our research group participates.

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DOI: 10.3217/jucs-014-16-2614

Authors: Gerrit Van Der Veer

Abstract: Cognitive Ergonomics is discussed as a systematic base for user interface design. The history of the discipline, explicitly existing now for about 25 years, is discussed, from participatory design, through various flavors of user centered design, to contextual design. Several persistent misunderstandings regarding the need for user interface design are analyzed. The concept of activity centered design is proposed as state of the art approach, and several techniques that support this paradigm are mentioned and illustrated.

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DOI: 10.3217/jucs-014-14-2381

Authors: Jaegeol Yim, Ilseok Ko, Jaesu Do, Jaehun Joo, Seunghwan Jeong

Abstract: Location-based service is one of the most popular buzzwords in the field of U-cities. Positioning a user is an essential ingredient of a location-based system in a U-city. For outdoor positioning, GPS based practical solutions have been introduced. However, the measurement error of GPS is too big for it to be used for U-campus services, because the size of a campus is smaller than that of a city. We propose the Relative-Interpolation Method to improve the accuracy of outdoor positioning. However, indoor positioning is also necessary for a U-campus because the GPS signal is not available inside buildings. For indoor positioning, various systems including Cricket, Active Badge, and so on have been introduced. These methods require special equipment dedicated to positioning. Our method does not require such equipment because it determines the user’s position based on the received signal strength indicators (RSSIs) from access points (AP) which are already installed for WLAN. The algorithm we use for indoor positioning is a kind of fingerprinting method. However, our algorithm builds a decision tree instead of a look-up table in the off-line phase. Therefore, the proposed method is faster than the existing indoor positioning methods in the real-time phase. We integrated our indoor and outdoor positioning methods and implemented a prototype indoor-outdoor positioning system on a laptop. The experimental results are discussed in this paper. In implementing the prototype, we also implemented a C# library function which can be used to read the RSSIs from the APs.

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DOI: 10.3217/jucs-014-09-1545

Authors: Roberto Arroyo, Miguel Gea, José Garrido, Pablo Haya

Abstract: So far, the Ambient Intelligence (AmI) paradigm has been applied to the development of a great variety of real systems. They use advanced technologies such as ubiquitous computing, natural interaction and active spaces, which become part of social environments. In the design of AmI systems, the inherent collaboration among users (with the purpose of achieving common goals) is usually represented and treated in an ad-hoc manner. However, the development of this kind of systems can take advantage of rich design models which embrace concepts in the domain of collaborative systems in order to provide the adequate support for explicit or implicit collaboration. Thereby, relevant requirements to be satisfied, such as an effective coordination of human activities by means of task scheduling, demand to dynamically manage and provide group- and context-awareness information. This paper addresses the integration of both proactive and collaborative aspects into a unique design model for the development of AmI systems; in particular, the proposal has been applied to a learning system. Furthermore, the implementation of this system is based on a blackboard- based architecture, which provides a well-defined high-level interface to the physical layer.

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DOI: 10.3217/jucs-014-09-1529

Authors: Manuel García-Herranz, Pablo Haya, Abraham Esquivel, Germán Montoro, Xavier Alamán

Abstract: This paper analyses the requirements of automation and adaptation in the so called perceptive environments. These environments are places with the ability of perceiving the context through sensors and other mechanisms. Focusing on personal/home environments, we present a first approach and prototype to semi-automatic adaptation of Perceptive Environments through a system of rule-based, configurable and modular agents, which are able to explain their behaviors and to adapt to the changing habits of the users. This prototype has been implemented over a real environment: a living room equipped with ambient intelligence capabilities. The core of the system relies on a set of modular agents equipped with rules. Those rules are composed of triggers, conditions and actions that enable them to express desired behaviors of the environment as well as to infer high-level context from low level context. One of the main objectives of the system is to leverage the control of the user over his/her own environment, making it easy to create powerful and personal behaviors without expert assistance. In this sense this work follows Greenberg’s thought of making "simple ideas simple to be done" [Greenberg 07].

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DOI: 10.3217/jucs-014-09-1496

Authors: Luis Tobar, Pedro Latorre, Elena Lapena

Abstract: The development, analysis and follow-up of the processes designed to assure the usability and accessibility of websites is a tedious work for the moderator or evaluator. This is why there is a necessity for tools that can automate the processes. There are some tools that cover some of the technical aspects, but no tools have been identified that can tackle the process as a whole. For these reasons the Aragonese Usability Laboratory decided to develop WebA (Web Analysis), with the objective to have a complete application. This application is designed through modules with the objective of covering all of the evaluation and analysis phases, and it concludes with a process management module. For the analysis phase a Card Sorting module (open & closed) has been developed that uses the hierarchical and multidimensional cluster analysis, which allows a better information architecture. For the evaluation phases, modules have been developed that allow the semiautomatic evaluation of usability through user satisfaction tests based on Nielsen heuristics and ISO standards, the evaluation of accessibility through the verification of WCAG 1.0 guidelines. The application concludes with a process design and evaluation management module, and modules that automatically generate the reports of the analysis carried out.

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DOI: 10.3217/jucs-014-09-1447

Authors: Montserrat Sendín, Víctor López-Jaquero, Cesar Collazos

Abstract: The advent of new advances in mobile computing has changed the manner we do our daily work, even enabling us to perform collaborative activities. However, current groupware approaches do not offer an integrating and efficient solution that jointly tackles the flexibility and heterogeneity inherent to mobility as well as the awareness aspects intrinsic to collaborative environments. Issues related to the diversity of contexts of use are collected under the term plasticity. A great amount of tools have emerged offering a solution to some of these issues, although always focused on individual scenarios. We are working on reusing and specializing some already existing plasticity tools to the groupware design. The aim is to offer the benefits from plasticity and awareness jointly, trying to reach a real collaboration and a deeper understanding of multi-environment groupware scenarios. In particular, this paper presents a conceptual framework aimed at being a reference for the generation of plastic User Interfaces for collaborative environments in a systematic and comprehensive way. Starting from a previous conceptual framework for individual environments, inspired on the model-based approach, we introduce specific components and considerations related to groupware.

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DOI: 10.3217/jucs-014-04-0508

Authors: Ronald Maier, Stefan Thalmann, Florian Bayer, Michael Krüger, Hendrik Nitz, Alexander Sandow

Abstract: Even though knowledge management has been around for more than a decade, so far concrete instruments that can be systematically deployed are still rare. This paper presents an optimization solution targeted at flexible management of office space considering knowledge management criteria in order to enhance knowledge work productivity. The paper presents the Flexible Office conceptual model and optimization solution. It discusses the theoretical foundation, assumptions and reasoning. A corresponding prototype was field-tested, successfully introduced, evaluated with the help of a series of interviews with users and improved according to their requirements. The paper also reflects on the organizational impact and lessons learned from field test and practical experience.

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DOI: 10.3217/jucs-014-01-0059

Authors: Stephan Lukosch

Abstract: Nowadays, more and more users make use of web-based collaborative systems. Users participate in communities or search for and provide information in webbased systems. They access shared resources which they need for their professional life or for learning. One of the major prerequisites of such web-based systems is that users have to be connected to the network. But life has become much more mobile over the last years. While traveling, e.g. to the office or the university, users often are disconnected from the network. This makes it difficult to interact with other users or to access shared resources. An application supporting a seamless transition between connected and disconnected phases would allow users to work at any time and place while maintaining the advantages of a web-based collaborative system once they are online again. In this article, we describe the requirements that a web-based collaborative system has to fulfill to enable a nomadic use. We show how we extended the web-based collaborative system CURE to fulfill these requirements and how our approach can be transferred to other web-based collaborative systems.

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DOI: 10.3217/jucs-013-06-0806

Authors: Carlos Henrique Q. Forster

Abstract: The spreadsheet metaphor has, over the years, proved itself valuable for the definition and use of computations by non-programmers. However, the computation model adopted in commercial spreadsheets is still limited to non-recursive computations and lacks abstraction mechanisms that would provide modularization and better reuse (beyond copy and paste). We investigate these problems by identifying a minimal set of requirements for recursive computations, designing a spreadsheet-based language with an abstraction definition mechanism, prototyping an interpreter and evaluating it with examples.

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DOI: 10.3217/jucs-013-02-0287

Authors: Leszek Borzemski

Abstract: In this paper we propose an application of data mining methods in the prediction of the availability and performance of Internet paths. We deploy a general decision-making method for advising the users in further usage of Internet path at particular time and date. The method is based on the clustering and tree classification data mining techniques. The usefulness of our method for prediction the Internet path behavior has been confirmed in real-life experiment. The active Internet measurements were performed to gather the end-to-end latency and packet routing information. The knowledge gathered has been analyzed using a professional data mining package via neural clustering and decision tree algorithms. The results show that the data mining can be efficiently used for the purpose of the forecasting the network behavior. We propose to build a network performance monitoring and prediction service based on proposed data mining procedure. We address our approach especially to the non-networkers of such networking frameworks as Grid and overlay networks who want to schedule their network activity but who want to be left free from networking issues to concentrate on their work.

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DOI: 10.3217/jucs-012-06-0581

Authors: Benjamin Blankertz, Guido Dornhege, Steven Lemm, Matthias Krauledat, Gabriel Curio, Klaus-Robert Müller

Abstract: We outline the Berlin Brain-Computer Interface (BBCI), a system which enables us to translate brain signals from movements or movement intentions into control commands. The main contribution of the BBCI, which is a non-invasive EEG-based BCI system, is the use of advanced machine learning techniques that allow to adapt to the specific brain signatures of each user with literally no training. In BBCI a calibration session of about 20min is necessary to provide a data basis from which the individualized brain signatures are inferred. This is very much in contrast to conventional BCI approaches that rely on operand conditioning and need extensive subject training of the order 50-100 hours. Our machine learning concept thus allows to achieve high quality feedback already after the very first session. This work reviews a broad range of investigations and experiments that have been performed within the BBCI project. In addition to these general paradigmatic BCI results, this work provides a condensed outline of the underlying machine learning and signal processing techniques that make the BBCI succeed. In the first experimental paradgm we analyze the predictability of limb movement long before the actual movement takes place using only the movement intention measured from the pre-movement (readiness) EEG potentials. The experiments include both off-line studies and an online feedback paradigm. The limits with respect to the spatial resolution of the somatotopy are explored by contrasting brain patterns of movements of left vs. right hand rsp. foot. In a second conplementary paradigm voluntary modulations of sensorimotor rhythms caused by motor imagery (left hand vs. right hand vs. foot) are translated into a continuous feedback signal. Here we report results of a recent feedback study with 6 healthy subjects with no or very little experience with BCI control: half of the subjects achieved an information transfer rate above 35 bits per minute (bmp). Furthermore one subject used the BBCI to operate a mental typewriter in free spelling mode. The overall spelling speed was 4.5-8 letters per minute including the time needed for the correction errors.

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DOI: 10.3217/jucs-012-03-0270

Authors: José Bravo, Ramón Hervás, Inocente Sánchez, Gabriel Chavira, Salvador Nava

Abstract: Ambient Intelligent (AmI) vision is a new concept materialized by the Six Framework Program of the European Community. It involves three key technologies: Ubiquitous Computing, Ubiquitous Communications and Natural Interfaces. With the increase in context aware applications it is important to keep these technologies in mind. In this paper we present a context aware application in a conference site based on the identification process using RFID. Furthermore the highlights of this proposal are based on the "ws" concepts. Three environments are modelled applying the "who" to the "when" and "where" to reach the "what". In this sense certain services are offered to the conference attendees, some of which are characteristics of this technology and others are the result of a context aware application, the visualization services named "Mosaics of Information".

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DOI: 10.3217/jucs-012-02-0160

Authors: Ping-Yu Hsu, Ping-Ho Ting

Abstract: As enterprises worldwide race to improve real-time management to improve productivity, customer services and flexibility, huge resources have been invested into enterprise systems (ESs). All modern ESs adopt an n-tier client-server architecture, which includes several application servers to hold users and applications. As in any other multi-server environment, the load distributions, and user distributions in particular, become a critical issue in tuning system performance. In stateful ESs, a user who logs onto an application server and stays connected to the server for an entire working session, which can last for days, evokes each application. Therefore, admitting a user onto an application server affects not only current but also future performance of that server. Although the n-tier architecture may involve web servers, there is little in the literature in Distributed Web Server Architectures that considers the effects of distributing users instead of individual requests to servers. The algorithm proposed in this paper gives specific suggestions in user distributions and the minimal number of servers required based on the application reusability threshold. A heuristic version of the algorithm is also presented to improve the performance. The paper also discusses how to apply association rules to predict new user behavior when distributing users in the run-time. The distributions recommended by the algorithms are compared against the Round-Robin distributions on a set of real data derived from a mid size company. The result shows that the user distributions suggested have better performance than Round Robin distributions.

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DOI: 10.3217/jucs-012-01-0006

Authors: Jean Roberts

Abstract: Much development work is ongoing addressing technologies and their application in the health domain, in order to achieve solutions that are non-invasive to every day life and work. As with many previous phases of informatics to support health, currently the developments are in islands and there is considerable untapped potential for synergy. Much research development is happening in other domains and show potential for health reversioning and deployment once proven. This paper explores some of the technological, societal and domain-specific issues surrounding this emerging concept of pervasiveness. It concludes that pervasive support to care is emerging but further work on minimizing risk and marketing the concept to professionals and laypeople is necessary to ensure an effective deployment.

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DOI: 10.3217/jucs-011-03-0378

Authors: Stefan Münzer, Bo Xiao

Abstract: E-learning at the workplace might be accomplished by synchronous cooperative learning sessions of small groups using net-based communication. This form of learning is suitable both for course-based e-learning as well as for knowledge transfer within the company. The small groups learn self-regulated, i.e. without the guidance of an instructor. However, the learning tasks are pre-defined and a specific learning process is precisely described. In the present study, the goal of the cooperative learning sessions is to deepen pre-existing declarative knowledge. During cooperative learning, group members are required to actively use, acquire, enrich and exchange their knowledge. In a field study carried out in a large software company, a software tool was used which supported the specific process by phase-specific delivering of instructions and learning materials as well as by means of process control (including turn-taking, role assignment, and coordination of task flow). The results of the empirical evaluation demonstrate a high amount of topic-oriented contributions and the realization of the expected learning activities. However, feedback data indicated a low acceptance of the software tool because of its restrictive process control. It is discussed that there might have been a non-optimal interaction between the factors technology and target group in the study.

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DOI: 10.3217/jucs-011-02-0357

Authors: Radoslaw Katarzyniak

Abstract: An original approach to modelling internal structure of artificial cognitive agents and the phenomenon of language grounding is presented. The accepted model for the internal cognitive space reflects basic structural properties of human cognition and assumes the partition of cognitive phenomena into conscious and non-conscious. The language is treated as a set of semiotic symbols and is used in semantic communication. Semiotic symbols are related to the internal content of empirical knowledge bases in which they are grounded. This relation is given by the so-called epistemic satisfaction relations defining situations in which semiotic symbols are adequate (grounded) representations of embodied experience. The importance of non-conscio us embodied knowledge in language grounding and production is accepted. An example of application of the proposed approach to the analysis of grounding requirements is given for the case of logic equivalences extended with modal operators of possibility, belief and knowledge. Implementation issues are considered.

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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-008-05-0491

Authors: Mark Maybury

Abstract: This article outlines new technologies in the areas of automated expertise finding, expert network discover, virtual place-based collaboration, and automated question answering. We illustrate each of these areas with implemented and in some cases empirically evaluated systems. Collectively, these illustrate new methods for automatic discovery of knowledge, experts, and communities in an effective and efficient manner.

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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-007-06-0458

Authors: Ivan Tomek

Abstract: Knowledge management systems provide three basic services: information capture, storage and organization, and access. This paper argues that collaborative virtual environments (CVEs) provide features that make them uniquely suited as an integral part of information capture. After introducing CVEs, we present our work in this area and outline our future plans.

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DOI: 10.3217/jucs-004-06-0604

Authors: Samuel Rebelsky, Fillia Makedon, P. Metaxas, Peter Gloor

Abstract: Abstract: In this paper, we discuss the design and development of a particular type of electronic publication that has gained recent popularity: electronic conference proceedings. We suggest that modern electronic proceedings should provide a high degree of interactivity. To support such interactivity, proceedings should include an extensive collection of features and diverse multimedia components. Features appropriate for electronic proceedings include annotation, presentation, and retrieval mechanisms. Conference papers and multimedia reproductions of conference presentations with features that allow readers to manipulate these reproductions particularly enhance the interactivity of electronic proceedings. Experience from interactive proceedings the authors have designed is also discussed. Special attention is given to the multiple roles video elements can and should play in interactive proceedings.

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DOI: 10.3217/jucs-003-08-0899

Authors: Simon Shum

Abstract: This paper describes an approach to capturing organisational memory, which serves to ground an analysis of human issues that knowledge management (KM) technologies raise. In the approach presented, teams construct graphical webs of the arguments and documents relating to key issues they are facing. This supports collaborative processes which are central to knowledge work, and provides a group memory of this intellectual investment. This approach emphasises the centrality of negotiation in making interdisciplinary decisions in a changing environment. Discussion in the paper focuses on key human dimensions to KM technologies, including the cognitive and group dynamics set up by an approach, the general problem of preserving contextual cues, and the political dimensions to formalising knowledge processes and products. These analyses strongly motivate the adoption of participatory design processes for KM systems.

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