DOI: 10.3897/jucs.152864

Authors: Claudio Alvarez, Andres Carvallo, Gustavo Zurita

Abstract: As student cohorts grow, real-time case-based learning discussions generate increasing volumes of textual data, intensifying the orchestration load teachers must manage. Reviewing and providing feedback on student responses promptly becomes increasingly challenging, demanding efficient methods to assist educators in selecting relevant contributions to steer classroom discussions. This study proposes a low-footprint natural language processing (NLP) approach that leverages small-scale models running on commodity hardware, avoiding the computational overhead and cost associated with large language models. Our system, integrated into EthicApp, a collaborative learning platform, employs pre-trained language models such as the Universal Sentence Encoder (USE) and Bidirectional Encoder Representations from Transformers for Spanish (BETO), along with traditional text-mining techniques like Term Frequency-Inverse Document Frequency (TF-IDF). Through expert evaluations, we found that BETO exhibited superior performance in identifying relevant student responses but required GPU acceleration. At the same time, USE provided an efficient alternative that outperformed TF-IDF and remained feasible for CPU-based execution. Additionally, the methods showed a tendency—most notably BETO—to select longer responses, which, rather than introducing selection bias, was interpreted as an indicator of deeper student engagement. No significant semantic bias was found, ensuring a fair representation of students’ perspectives. Our findings suggest that low-footprint NLP can effectively reduce teacher orchestration load, enabling more targeted feedback without requiring extensive computational resources.

HTML

PDF

DOI: 10.3897/jucs.108446

Authors: Shanshan Jia, Gaukhar A. Kamalova, Dmytro Mykhalevskiy

Abstract: The importance of the topic under investigation stems from the burgeoning prominence of the Internet of Things (IoT) paradigm and the consequent imperative to devise and institute an efficacious methodology for neighbour detection that facilitates supplementary connections to mobile nodes. This research primarily aims to elucidate a mobile handover technique aligning with the neighbour discovery paradigm inherent in 6LoWPAN. The methodological framework employed herein amalgamates a systematic analysis of the foundational tenets governing 6LoWPAN communication standards over the IPv6 protocol in the context of IEEE 802.15.4aa personal wireless networks, supplemented with empirical evaluation of message propagation dynamics among discrete nodes of a designated personal wireless network. The findings of this investigation underscore the pre-eminence of the 6LoWPAN networking standard as a prime vehicle for bolstering the dependable communication of IoT's remote entities, contingent upon the utilization of the IPv6 communication protocol. This iteration of the Internet protocol is superior, particularly in surveillance contexts, given its expansive address capacity (128 bits) juxtaposed against its antecedent, the IPv4 protocol (32 bits). The inherent adaptability of this network connection augments the quality of mobile handover, especially when one considers the real-world application of 6LoWPAN's neighbour discovery auxiliary communication standard. The tangible implications of these findings beckon their potential utility in satiating the demands of IoT system users and actualizing the network collaboration ethos intrinsic to the 6LoWPAN communication standard.

HTML

PDF

DOI: 10.3897/jucs.94514

Authors: Fernando Terroso-Saenz, Andres Muñoz

Abstract: Predicting human mobility is a key element in the development of intelligent transport systems. Current digital technologies enable capturing a wealth of data on mobility flows between geographic areas, which are then used to train machine learning models to predict these flows. However, most works have only considered a single data source for building these models or different sources but covering the same spatial area. In this paper we propose to augment a macro open-data mobility study based on cellular phones with data from a road traffic sensor located within a specific motorway of one of the mobility areas in the study. The results show that models trained with the fusion of both types of data, especially long short-term memory (LSTM) and Gated Recurrent Unit (GRU) neural networks, provide a more reliable prediction than models based only on the open data source. These results show that it is possible to predict the traffic entering a particular city in the next 30 minutes with an absolute error less than 10%. Thus, this work is a further step towards improving the prediction of human mobility in interurban areas by fusing open data with data from IoT systems.

HTML

XML

PDF

DOI: 10.3897/jucs.86891

Authors: Aurora Polo-Rodríguez, Pietro Dionisio, Francesco Agnoloni, Ana Perandrés Gómez, Cristiano Paggetti, Lucía González López, Alfonso Cruz Lendínez, Macarena Espinilla-Estévez, Javier Medina-Quero

Abstract: Active ageing is a multidimensional process for achieving the potential quality of life and meaning in the life cycle. In the context of the Andalusian region in Spain, where the majority of the population is over 60 years old and lives in rural areas, it has become a key challenge. That is why the European projects within the Framework Programme for Research and Innovation, such as Pharaon - Pilots for Active and Healthy Ageing, promote technologies adapted by and for our elders. In the case of the Andalusian pilot, part of this project, we have selected a social network adapted to them, enabling them to communicate with the community at home and share their experiences. In addition, to improve their physical fitness, a device to count active minutes and steps is included, which provides users and caregivers with a visible and objective metric of daily health status. The technology has been evaluated following a well-defined methodology, which is described in this work to promote the deployment of technology in large-scale pilots. A specific architecture (Information System for Active Ageing in Andalusia - ISA3) and the components evaluated within a common ecosystem (Pharaon Project) are presented.

HTML

XML

PDF

DOI: 10.3897/jucs.90663

Authors: Venilton FalvoJr, Anderson da Silva Marcolino, Nemésio Freitas Duarte Filho, Edson OliveiraJr, Ellen Francine Barbosa

Abstract: The popularity of mobile devices in all social classes has motivated the development of mobile learning (m-learning) applications. The existing applications, even having many benefits and facilities in relation to the teaching-learning process, still presents problems and challenges, es- pecially regarding the development, reuse and architectural standardization. Particularly, there is a growing adoption of the Software Product Line (SPL) concept, in view of research that investigates these gaps. This paradigm enables organizations to explore the similarities and variabilities of their products, increasing the reuse of artifacts and, consequently, reducing costs and development time. In this context, we discuss how systematic reuse can improve the development of solutions in the m-learning domain. Therefore, this work presents the design, development and experimental evaluation of M-SPLearning, an SPL created to enable the systematic production of m-learning applications. Specifically, the conception of M-SPLearning covers from the initial study for an effective domain analysis to the implementation and evaluation of its functional version. In this regard, the products have been experimentally evaluated by industry software developers, pro- viding statistical evidence that the use of our SPL can speed up the time-to-market of m-learning applications, in addition to reducing their respective number of faults.

HTML

XML

PDF

DOI: 10.3897/jucs.68852

Authors: Agnes Kukulska-Hulme, Jorge Arus-Hota, Jesus Garcia Laborda

Abstract: The emerging paradigm of mobile open social learning for languages (MOSL4L) integrates the three elements of mobile, open and social, and in so doing it creates the idea of a conceptually different language learning space. It is a space full of opportunity and challenge, relevant to a post-pandemic world in which we are looking for ways to build back better. The paper discusses tensions between formal and informal language learning and the nature of learning outcomes in MOSL4L. It focuses on the needs of individuals while also considering the characteristics of the virtual spaces in which they participate. It highlights the potential of micro experiences and learning moments as structures that are well aligned with MOSL4L. It suggests developments in language curricula to take account of communication challenges being identified in the contemporary world. Many more new learning designs and software architectures will have to be developed to match the possibilities generated by the MOSL4L space.

HTML

XML

PDF

DOI: 10.3897/jucs.64591

Authors: Christian Moreira Matos, Vítor Kehl Matter, Márcio Garcia Martins, João Elison da Rosa Tavares, Alexandre Sturmer Wolf, Paulo César Buttenbender, Jorge Luis Victória Barbosa

Abstract: People with disabilities and the elderly face difficulties to fulfill their accessibility needs in their daily life routines, mainly when they have an emergency demanding speedy and specific assistance. This article proposes the SafeFollowing, a collaborative model to help people with disabilities and the elderly in smart assistive cities. The main contribution of this work is the specification of a decentralized model of ubiquitous accessibility, which involves public agents and volunteers to attend the users’ requests. SafeFollowing also allows the use of police vehicles mapping, in order to provide a specific follow-up in adverse situations of daily life. The model was validated through experiments in real case scenarios by 14 public agents and 11 elderly and people with disabilities. The results showed that 100% of evaluators (users and agents) stated that the model was useful and 82% of users and 100% of agents considered that SafeFollowing was easy to use. The experiments also allowed the learning of 5 relevant lessons on technological and usability aspects of SafeFollowing that are recorded in this article.

HTML

XML

PDF

DOI: 10.3217/jucs-025-10-1221

Authors: K. Shankar, Mohamed Elhoseny

Abstract: In wireless communication, Mobile Ad Hoc Network (MANET) consists of a number of mobile nodes which are communicated with each other without any base station. One of the security attacks in MANETs is Packet forwarding misbehaviour attack; this makes MANETs weak by showing message loss behavior. For securing message transmission in MANET, the work proposes Energy Efficient Clustering Protocol (EECP) with Radial Basis Function (RBF) based CH is elected for formed Clusters. Moreover, here some Network measures are considered to detect the malicious nodes and CH model that is speed, mobility, trust and so on. The trust value of the node is computed from the neighbor node which helps in further location to find a malicious node in the network to avail message drop and energy consumption (EC). After detecting malicious nodes, Multi secure Protocols that is Secure Efficient Distance Vector Routing (SEDV) and Secure Link State Routing Protocol (SLSP) with encryption technique used for message security. If the" HELLO" message sending by the sender, its encrypted and decrypted triples in receiver end to get the plain message, this technique is Triple Data Encryption Standard (TDES). Finally, the implementation results are evaluated to analyze the message security level of the proposed system in MANET in terms, of Packet to Delivery Ratio (PDR, Network Life Time (NLT) and some other important Measures.

HTML

XML

PDF

DOI: 10.3217/jucs-024-10-1452

Authors: Rodrigo Souza, João Lopes, Cláudio Geyer, Anderson Cardozo, Adenauer Yamin, Jorge Luis Victória Barbosa

Abstract: The recent advances in the Internet of Things (IoT), which has provided increasing availability of networked sensors and actuators, have given context awareness research in the UbiComp area a new perspective. In this sense, the main contribution of this paper is the proposition of a distributed architecture for IoT, called CoIoT (Context awareness in the Internet of Things). This architecture is designed to provide proactive management of the interactions with the physical environment. To evaluate the functionalities of the proposed architecture we implemented a case study in the agricultural area, specifically in the monitoring of seed analysis laboratory.

HTML

XML

PDF

DOI: 10.3217/jucs-024-07-0846

Authors: Alfonso Garcia-De-Prado, Guadalupe Ortiz, Juan Boubeta-Puig, David Corral-Plaza

Abstract: Over the last years, air pollution and air quality have received increasing attention in the scope of Internet of Things and smart cities, since they can seriously affect citizens' health. However, current systems for air quality monitoring and notification lack essential key requirements in order to be effective as far as users' access to the information is concerned and, particularly, the provision of context-aware notifications. This paper presents Air4People, an air quality monitoring and context-aware notification system, which submits personalized alerts to citizens based on several types of context, whenever air quality-related health risks are detected for their particular context.

HTML

XML

PDF

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.

HTML

XML

PDF

DOI: 10.3217/jucs-024-03-0277

Authors: Yuanyuan Qiao, Yan Wu, Yaobin He, Libo Hao, Wenhui Lin, Jie Yang

Abstract: We are facing an era of Online With Offline (OWO) in the smart city - almost everyone is using various online services to connect friends, watch videos, listen to the music, download resources, and so on. Our online behaviors are separated by different domains, which may cause serious problem in the area of cross-domain recommendation, advertising, and criminal tracking in online and offline world, since it is a very challenging task to link user online behaviors belonging to the same natural person. Existing methods usually tackle user online behavior linkage problem by estimating the profile content similarity between two different online services. However, the profile contents in heterogeneous online services are unreliable or misaligned, and the proposed methods are always limited to several services in a specific domain. In order to link individual's online behavior across domains, in this paper, we propose user Online Behavior Linkage across Domains (OBLD), a novel hybrid model, to link user online behavior across domains with Internet traffic. It derives several signifficant attributes from users' online behaviors, such as user digital identity, various fingerprints of terminals and browsers, spatio-temporal behavior of users, and leverages a supervised classi_cation method to discover the relationship between users' online behaviors. Also, the proposed model has unsupervised setting for dataset with non or few label data if a certain percentage of user digital identities can be extracted from original dataset. By using real-world network traffic collected from two large provinces in China, we evaluate the OBLD model and the linkage precision achieves 89% and 97.9% for two datasets respectively. Especially, the inputs of OBLD, i.e., network traffic flows, cover all online behavior of users who connect with Internet through monitored networks, which makes it possible to link online behaviors of users in whole online world.

HTML

XML

PDF

DOI: 10.3217/jucs-024-02-0108

Authors: Bibeg Limbu, Halszka Jarodzka, Roland Klemke, Fridolin Wild, Marcus Specht

Abstract: Augmented reality and sensor technologies have been analysed extensively in several domains including education and training. Although, varieties of use cases and applications exist, these studies were conducted in controlled laboratory environments. This paper reports on the first user study of augmented reality prototype developed to support students to learn from trainers in professional domains using augmented reality and sensors. The prototype records the performance of trainers in the first phase to support students by making it available during practice in the second phase. The performance data is made available to both the students and trainers in the third phase for reflection. A total of 142 participants which included trainers and students from three professional domains, namely 1) aircraft maintenance 2) medical imaging and 3) astronaut training, evaluated the prototype. The trainers used the prototype to record their performance while the students used the prototype to learn from the recorded performance. Participants from the three professional domains evaluated the usability of the prototype by means of a questionnaire. Randomly selected participants were also interviewed to collect their opinions and suggestion for further usability improvement. Furthermore, they also evaluated the implementation of the instructional design methods, which were identified prior in a literature review, with a brief questionnaire. The questionnaire was designed to measure the acceptance of the implementation of instructional design methods and to evaluate its adherence to the authors definition. The results of this study show that the usability of the prototype is below expected standard acceptable level. The results of the questionnaire on the implementation of the instructional design methods varied show above average acceptance levels by both the trainers and the students in the three professional domains. To conclude, the prototype shows potential to be used in different domains to support expertise development.

HTML

XML

PDF

DOI: 10.3217/jucs-023-12-1147

Authors: Edgar Marçal, Rossana Maria de Castro Andrade, Windson Viana

Abstract: While field trips promote the scientific spirit of students by increasing their ability of observation and discovery in various areas of knowledge, the introduction of ubiquitous technologies, such as sensors and actuators, during the field trips, improves students' motivation and learning. However, the development of systems for this purpose implies to deal with the seamless treatment of the devices heterogeneity, absence of fixed communication infrastructure, dynamics of the computational elements of the environment, and support for user mobility. This paper presents then the development and evaluation of a system, called Ubiquitous Field Classes Inventor (UFC-Inventor), which aims to promote the use of mobile and ubiquitous technologies in field trips. The UFC-Inventor evaluation is performed in two stages: first, with five teachers of natural sciences; and later, during a field trip with seventeen students. Two of the teachers were from higher education (Geology and Animal Science) and three of them from high school (two in Geography and one in Biology). The seventeen students who participated in the case study were undergraduate students in the third year of their Geology course. The results suggest a good acceptance of UFC-Inventor and indicate that its execution occurred correctly.

HTML

XML

PDF

DOI: 10.3217/jucs-022-08-1123

Authors: Guilherme Melo e Maranhão, Renato Bulcão-Neto

Abstract: A great challenge in context-aware computing is dealing with the heterogeneity and volume of sensors data. A problem regarding that scenario is to notify context-aware applications, which have distinct interests of context events in terms of volume, semantic and complexity, in an efficient and relevant manner. Aiming to solve this problem, this research focuses on a new approach for filtering semantic context towards supporting context dissemination. This mechanism is to be aligned with the reasoning capabilities of a context-aware solution and also be maintainable and extensible to efficiently support changes in an ontological model. A performance evaluation is carried out in a simulated scenario of vital signs monitoring in Intensive Care Units and wards. Hermes Interpreter's behaviour is analysed when dealing with filters of different complexities and also an increasing number of subscribers per vital sign. Results demonstrate the high cost of the semantic filtering mechanism in comparison with pure context reasoning activities.

HTML

XML

PDF

DOI: 10.3217/jucs-021-08-1061

Authors: Ahlem Harchay, Lilia Cheniti-Belcadhi, Rafik Braham

Abstract: With the increasing development of mobile technologies, the learning environment is currently undergoing a major shift. Access to contextual information in a mobile learning environment aims to meet the needs of learning and assessment personalization according to various learners' profiles and a range of learning contexts. Semantic Web technologies have been applied in recent years with different purposes in education. But, their applications for generating useful personalized mobile assessment resources have not been researched enough so far. In this paper, an approach making use of semantic Web technologies to support personalized self-assessment in mobile environments is described. Assessment techniques are formalized with First Order Logic rules which allow to personalize assessment activities. We also propose an algorithm for semantic assessment resources retrieval. Finally, a Mobile Semantic Web Assessment Personalization system is presented. The qualitative and quantitative evaluation of the proposed system is also provided.

HTML

XML

PDF

DOI: 10.3217/jucs-021-07-0959

Authors: Andreea Molnar, Cristina Muntean

Abstract: When using mobile phones for learning purpose, video content is considered to be the preferred type of multimedia content. However, the video file has a big size in comparison to text or audio and might lead to a high delivery cost when transmitted over a mobile network, a cost that not all users are willing to pay. Concerns regarding the monetary cost for accessing data content through mobile networks have been raised by various researchers. A solution that considers the user preference for trading off between video quality and price in order to reduce the content delivery cost is presented. This paper also evaluates the proposed solution and presents the results of an experimental study that assesses the video content adaptation impact on information assimilation. The results show that although video quality is reduced information assimilation is not negatively affected by the adaptation. This holds true regardless of the mobile device used in the study.

HTML

XML

PDF

DOI: 10.3217/jucs-020-15-2005

Authors: Jinghuai She, Xi Zhang, Weiguang Wang, Patricia Ordóñez de Pablos

Abstract: Social media and mobile internet are both hottest topics in internet technologies which bring great challenges and wonderful opportunities for a large number of researchers in recent years. In some research fields, i.e., telemedicine or e-healthcare, Chinese researchers quickly took advantage of the spread of social media and mobile internet. In this study, we conducted a citation analysis with CiteSpace II by comparing the performance between researchers from China and advanced countries (e.g., USA) in Telemedicine field from 2005-2013. Although there remain huge gaps between China and developed countries, we found that social networks and mobile internet helped Chinese researchers to narrow the gap quickly in recent years. We also found that in the sub fields such as "SNS-facilitated telemedicine" or "m-healthcare", Chinese researchers even achieved similar performance as compared with world class researchers. These findings implicate that SNS or mobile internet may help researchers in developing countries to bridge the digital divide and enhance "late-mover advantage".

HTML

XML

PDF

DOI: 10.3217/jucs-020-12-1670

Authors: Juan Muñoz-Cristóbal, Alejandra Martínez-Monés, Juan Asensio-Pérez, Sara Villagrá-Sobrino, Javier Hoyos-Torio, Yannis Dimitriadis

Abstract: The use of immersive environments such as 3D virtual worlds (3DVWs) and augmented reality (AR) in education has been profusely explored during the last decades, showing significant evidence of its benefits for learning. However, the attempts to integrate immersive environments in everyday educational practice are hampered by the difficulties that these environments pose to teachers willing to set them up within the already demanding ecology of technological resources present in the classroom. GLUEPS-AR is a system aimed to help teachers deploy and enact learning designs that make use of web technologies (Virtual Learning Environments and Web 2.0 tools), as well as immersive environments such as virtual globes (e.g. Google Earth) used as 3DVW, and general-purpose mobile AR apps. This paper presents the evaluation of the support provided by GLUEPS-AR for teachers that want to appropriate immersive environments in their everyday practice with an affordable orchestration effort. The evaluation followed an interpretive research perspective, and it was carried out in the context of an authentic learning situation about advertising, conducted at a university undergraduate course for pre-service teachers. The results of the evaluation showed that GLUEPS-AR effectively supported the teacher in seamlessly embedding 3DVWs and AR in her practice.

HTML

XML

PDF

DOI: 10.3217/jucs-020-12-1649

Authors: Jorge Luis Victória Barbosa, Débora Nice Ferrari Barbosa, Jezer De Oliveira, Solon Andrade Rabello Jr.

Abstract: This article proposes a decentralized infrastructure for ubiquitous learning environments called Global. The two main contributions of Global are its decentralized strategy and its extensible architecture based on software agents. Global can be specialized to create ubiquitous learning environments through the extension of its agents or through the addition of new agents. The article presents the infrastructure architecture, describing the agents and auxiliary components. Moreover, the article approaches the implementation and evaluation of Global through two applications dedicated to education. The evaluation showed that the infrastructure could be used for the development of decentralized learning systems, supporting specifically the characteristics considered as strategic for ubiquitous learning.

HTML

XML

PDF

DOI: 10.3217/jucs-020-09-1327

Authors: João Lopes, Rodrigo Souza, Cláudio Geyer, Cristiano Costa, Jorge Luis Victória Barbosa, Ana Pernas, Adenauer Yamin

Abstract: The development of applications that adapt to the environment and remain running even when the user is moving or switching device, remains an open research challenge. In this article we present a view of the EXEHDA middleware and a new service created for dynamic adaptation. EXEHDA is service-oriented, adaptive and was conceived to support the execution of ubiquitous applications. The main concept in the proposed design for the middleware and for the application is context awareness expressed in an adaptive behavior. The middleware manages and implements the follow-me semantics for ubiquitous applications. This is also a key to provide functionality adapted to the constraints and unpredictability of the large-scale environment. To achieve this objective, EXEHDA employs various strategies in its services to allow the adaptation to the current context, such as on-demand adaptive service loading, and dynamic discovery and configuration. In that sense, EXEHDA provides services for distributed adaptive execution, context recognition, ubiquitous storage and access, and anonymous and asynchronous communications. To evaluate the new service proposed for dynamic adaptation we developed a case study, implementing an application in medical area. Analyzing the results we can see that the users found the application easy to use and usefulness for health workers at a hospital. This work is sponsored by RNP, FINEP and CNPq - Brazilian Foundations.

HTML

XML

PDF

DOI: 10.3217/jucs-020-01-0039

Authors: Christian Haintz, Karin Pichler, Martin Ebner

Abstract: Question-driven Audience Response Systems (ARSs) are in the focus of research since the 1960s. Since then, the technology has changed and therefore systems have evolved too. This work is about conception and implementation of the web-based ARS RealFeedback which uses the principle of bring your own device (BYOD). A state-of-the-art analysis compares the features of existing web-based ARSs. The most important findings are used for the conception and the implementation of the system. Thinking-aloud tests, and the first usages during lectures confirm that the chosen requirements are very significant and valuable for lecturers.

HTML

XML

PDF

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.

HTML

XML

PDF

DOI: 10.3217/jucs-019-16-2404

Authors: Tran Ho, Ho-Seok Kang, Sung-Ryul Kim

Abstract: In the modern life, SMS (Short Message Service) is one of the most necessary services on mobile devices. Because of its popularity, many companies use SMS as an effective marketing and advertising tool. Also, the popularity gives hackers chances to abuse SMS to cheat mobile users and steal personal information in their mobile phones, for example. In this paper, we propose a method to detect spam SMS on mobile devices and smart phones. Our approach is based on improving a graph-based algorithm and utilizing the KNN Algorithm - one of the simplest and most effective classification algorithms. The experimentation is carried out on SMS message collections and the results ensures the efficiency of the proposed method, with high accuracy and small processing time enough for detecting spam messages directly on mobile phones in real time.

HTML

XML

PDF

DOI: 10.3217/jucs-019-16-2385

Authors: Youngho Park, Chul Sur, Sanguk Shin, Kyung-Hyune Rhee, Changho Seo

Abstract: Vehicular Delay Tolerant Networks (VDTNs) are characterized model of Vehicular Ad Hoc Networks where vehicles disseminate messages through fixed relay nodes placed on roadside by utilizing a store-carry-forward method. In this paper, we propose a secure message delivery protocol for protecting receiver-location privacy in socialspot-based VDTN because location privacy is one of the most important security requirements. To design a simplified protocol, we eliminate the use of conventional pseudonym-based vehicle identification accompanied with a complex pseudonymous certificate management. Instead, we introduce an identity-hidden message indexing which enables a receiver vehicle to query a message whose destination is itself to the socialspot RSU without revealing its identity, and we make use of non-interactive key agreement scheme to establish a secure communication channel between message source and destination vehicles. Furthermore, we demonstrate experimental results to confirm the reduced cryptographic overhead and the effectiveness of privacy preservation for the proposed protocol.

HTML

XML

PDF

DOI: 10.3217/jucs-019-09-1219

Authors: Antonio Jara, David Fernandez, Pablo Lopez, Miguel Zamora, Antonio Skarmeta, Leandro Marin

Abstract: Bluetooth Low Energy (BLE) is extending Bluetooth technology to devices with lower communication requirements and higher constraints in terms of memory capabilities and power autonomy. Thereby, BLE makes feasible the wireless transmission of information from smart objects such as wearable clinical devices, ambient sensors and actuators. These smart objects are starting to be internet-enabled devices, reaching the so denominated Internet of Things (IoT). Our research work is focused on analyze the capabilities of these technologies for continuous data transmission and integration of clinical sensors in home-care and Ambient Assisted Living environments. For this purpose, this work analyses exhaustively the capabilities from BLE and compare this with the capabilities from Bluetooth 2.1. In addition, it has been considered the communications requirements from different clinical devices such as an electrocardiogram (ECG) and a capnograph. It is concluded that the performance from BLE is lower than Bluetooth Classic (Bluetooth 2.1) for continuous communications, since BLE is based on attributes (datapoints) transfer instead of offering a communication session where can be transmitted as much packets as required, without any size constraint. Therefore, it is necessary to perform data compression/aggregation when the amount of data to send is too large to be stored in a BLE attribute. This work also presents how to apply pre-processing techniques that greatly reduces the transmission overload (performs signal compression) in order to allow the continuous transmission of the ECG and capnograph signal through BLE making so feasible the integration of continuous clinical devices via BLE.

HTML

XML

PDF

DOI: 10.3217/jucs-018-15-2165

Authors: Davinia Hernández-Leo, Raul Nieves, Ernesto Arroyo, Andrea Rosales, Javier Melero, Josep Blat

Abstract: Carrying out collaborative learning activities (supported by technologies or not) typically involves the coordination of multiple participants, in their dynamic assignment to groups and roles and in the distribution of resources and tools to specific group or individuals. While the mechanisms required to address these coordination aspects in digital educational spaces have been largely studied, less research has been conducted on orchestration support for facilitating this coordination in (technology-enhanced) physical spaces, such as the classroom or the playground. This paper presents the Signal Orchestration System (SOS), a system that augments the physical environment with digital signals indicating orchestration aspects. The SOS facilitates its integration with digital educational spaces to allow transitioning activities from digital to physical spaces. The paper describes the SOS system and its underlying architecture through a functional prototype that has been developed to show its feasibility and to enable its evaluation in authentic situations. The main components of the prototype include a Manager, where orchestration visual and auditory signals are configured, changed on the fly and transmitted, and three different designs of Wearable Signaling Devices, which are carried by participants and render the orchestration signals. The prototype has been used in two different experiments in the context of a real course applying adaptations of the well-known Jigsaw collaborative learning flow pattern. The results show that the SOS enables a flexible dynamic orchestration of the collaborative activities.

HTML

XML

PDF

DOI: 10.3217/jucs-017-02-0332

Authors: Carlos Hurtado, Luis Guerrero

Abstract: Computer Supported Collaborative Learning could highly impact education around the world if the proper Collaborative Learning tools are set in place. In this paper we describe the design of a collaborative learning activity for teaching Chemistry to Chilean students. We describe a PDA-based software tool that allows teachers to create workgroups in their classrooms in order to work on the activity. The developed software tool has three modules: one module for teachers, which runs on a PC and lets them create the required pedagogical material; second, there is a PDA module for students which lets them execute the activity; finally, a third module allows the teacher set workgroups and monitor each workgroup during the activity.

HTML

XML

PDF

DOI: 10.3217/jucs-016-17-2333

Authors: David G. Rosado, Eduardo Fernández-Medina, Javier López, Mario Piattini

Abstract: The idea of developing software through systematic development processes to improve software quality is not new. Nevertheless, there are still many information systems such as those of Grid Computing which are not developed through methodologies that are adapted to their most differentiating features. A systematic development process for Grid systems that supports the participation of mobile nodes and incorporates security aspects into the entire software lifecycle will thus play a significant role in the development of systems based on Grid computing. We are creating a development process for the construction of information systems based on Grid Computing, which is highly dependent on mobile devices, in which security plays a highly important role. One of the activities in this process is that of analysis which is focused on ensuring that the system's security and functional requirements are elicited, specified and modelled. In our approach, this activity is driven by use cases and supported by the reusable repository. This obtains, builds, defines and refines the use cases of the secure Mobile Grid systems which represent the functional and non-functional requirements of this kind of systems. In this paper, we present the proposed development process through which we introduce the main aspects of the UML profile defined for building use case diagrams in the mobile Grid context through which it is possible to represent specific mobile Grid features and security aspects, showing in detail how to build use case diagrams for a real mobile Grid application by using our UML profile, denominated as GridUCSec-Profile.

HTML

XML

PDF

DOI: 10.3217/jucs-016-12-1650

Authors: Yang Cai

Abstract: Analyzing human motion in a building has been an active subject in Ambient Intelligence and Universal Design for many years. In this study, we present a rapid prototype of a mobile and interactive sensing platform for smart buildings. The biologically inspired robot can follow the moving person around, memorize the motion patterns in form of sequences of symbols, and detect surprising events, based on similarity between the priori and posteriori probability distributions. The key modules in this study have been prototyped and tested with real-world data, such as the two–month sensory data in a building. Furthermore, the author believes that simple and recursive algorithms would enable mobile robots to simulate natural ethological intelligence.

HTML

XML

PDF

DOI: 10.3217/jucs-016-12-1556

Authors: Roc Messeguer, Leandro Navarro, Pedro Damian-Reyes, Jesus Favela

Abstract: In Collaborative Learning, groups of students work together using traditional and computer-based tools or applications. Participants are continuously moving and reorganizing in groups as tasks develop and the contextual information about the physical arrangement of people within groups determines the context of each sub-activity. The electronic environment needs to be in sync with the physical arrangement of the groups, but providing group context information to computer-based tools cannot effectively be done manually. This paper explores and addresses the problem of automating group awareness in CSCL applications by estimating group arrangements from location sensors and the history of interaction. We derive from case studies the requirements for context-awareness in collaborative learning, focusing on the Jigsaw technique supported by mobile devices. In our prototype system with real users, groups are detected from the location of the students within the classroom. However, this information needs filtering to avoid disturbing interruptions caused by uncertain location measures. A three-phase filtering strategy is proposed to manage uncertain contextual information by identifying sources of uncertainty, representing uncertain information, and determining how to proceed. Validation with experimental data shows the usefulness of introducing mobile devices with group-supporting applications that incorporate automatic group awareness. Results show that by managing uncertainty in the estimation of location, group membership information becomes reliable enough to satisfy the need for supporting collaborative learning with applications that are automatically group-aware, without introducing extra burdens or interruptions.

HTML

XML

PDF

DOI: 10.3217/jucs-016-12-1500

Authors: Juan García-Vázquez, Marcela Rodríguez, Monica Tentori, Diana Saldaña, Ángel Andrade, Adán Espinoza

Abstract: Ageing is a global phenomenon which has motivated many research and development projects with the aim of providing computing services that support the active and independent living of the elderly. To integrate the ambient intelligence (AmI) vision into the home environment to allow elders to "age in place", it has been identified the necessity of providing high-level software support for creating ambient assisted living (AAL) environments. We propose activity-aware computing to allow smart environments to provide continuous activity awareness and opportunistically offer assistance aimed at supporting the elders’ current activity. This new paradigm calls for novel tools to help developers mirror human activities in the digital domain, and adapt smart environments based on the activities executed by the users. This paper proposes the use of autonomous agents to cope with the design issues for developing activity-aware systems. We specialized the SALSA agent architecture by incorporating customizable activity-aware mechanisms to infer and represent activities. We illustrate the capabilities offered by SALSA autonomous agents through a design of an activity-aware application for helping elders to manage their medication activity.

HTML

XML

PDF

DOI: 10.3217/jucs-016-03-0341

Authors: Susana Bagüés, Andreas Zeidler, Cornel Klein, Carlos Valdivielso, Ignacio Matias

Abstract: Protection of personal data in the Internet is already a challenge today. Users have toactively look up privacy policies of websites and decide whether they can live with the terms of use. Once discovered, they are forced to make a "`take or leave"' decision. In future living andworking environments, where sensors and context-aware services are pervasive, this becomes an even greater challenge and annoyance. The environment is much more personalized and userscannot just "`leave"'. They require measures to prevent, avoid and detect misuse of sensitive data, as well as to be able to negotiate the purpose of use of data. We present a novel modelof privacy protection, complementing the notion of enterprise privacy with the incorporation of personal privacy towards a holistic privacy management system. Our approach allows non-expertusers not only to negotiate the desired level of privacy in a rather automated and simple way, but also to track and monitor the whole life-cycle of data.

HTML

XML

PDF

DOI: 10.3217/jucs-015-09-1833

Authors: Nelson Baloian, Gustavo Zurita

Abstract: Nowadays, we are experiencing a rapid development in mobile computing because of the sinking prices of the mobile devices and the availability of wireless networks that can connect them. The ability of many of these devices to set up ad-hoc networks by proximity allows face-to-face interaction combined with mobility. However, mobile devices are much weaker in computing power compared with desktop or laptop computing. Therefore, a key aspect to ensure success of an application supporting mobile learning is whether mobility is really needed for the activity it supports and if mobile devices do really represent an added value compared with the same application implemented on non-mobile devices. This work presents MCI-Supporter, an application supporting collaborative learning practises in the classroom. MCI-Supported was conceived by first analyzing the best known collaborative learning practices trying to find out which are the real needs for mobility and face-to-face interaction and then designing the application supporting learning activities where mobile computing does really represents an added value compared to the desktop computing scenario.

HTML

XML

PDF

DOI: 10.3217/jucs-015-05-1007

Authors: Changhoon Lee, Jongsung Kim, Seokhie Hong, Yang-Sun Lee

Abstract: Wireless networks, telecommunications, and information technologies connected de-vices in pervasive computing environments require a high speed encryption for providing a high security and a privacy. The CHESS-64 based on various controlled operations is designed forsuch applications. In this paper, however, we show that CHESS-64 doesn't have a high security level, more precisely, we present two related-key differential attacks on CHESS-64. The first at-tack requires about 244 data and 244 time complexities (recovering 20 bits of the master key)while the second attack needs about 239 data and 239 time complexities (recovering 6 bits of themaster key). These works are the first known cryptanalytic results on CHESS-64 so far.

HTML

XML

PDF