http://www.jucs.org/jucs_articles_by_Category/L. JUCS Topic L. - Science and Technology of Learning Verlag der Technischen Universität Graz Universiti Malaysia Sarawak 2011-03-07T11:27:24+01:00 http://www.jucs.org/jucs_16_21/assessing_the_learning_path Finding suitable ways to achieve particular learning goals is not an easy task, both in initial education and lifelong learning. To facilitate selection, personalisation and navigation of learning paths we propose to describe learning paths in a formal and uniform way by means of a learning path specification. This paper explains the rationale behind the Learning Path Specification. Based on a framework developed for the evaluation of the specification the paper describes a study that was carried out to establish pragmatic quality, i.e. whether stakeholders can understand and use the specification. The paper explores the relationship between the concepts pragmatic quality, usability, and desirability, and distinguishes first-order and second-order pragmatic quality, relating it to different stakeholders: software developers and end-users. First-order pragmatic quality of the Learning Path Specification was evaluated during the process of developing a tool that describes learning paths according to the specification: the Learning Path Editor. Second-order pragmatic quality was evaluated through workshop sessions with end-users involving some hands-on experiences with this tool. The paper describes adaptations made to the specification in the process of developing the Editor. End-user evaluations were quite positive, leading to one more adaptation. Berlanga, Adriana J.; Finders, Anton; Herder, Eelco; Martens, Harry; Hermans, Henry; Vogten, Hubert; Gallardo, Javier Melero; Janssen, José; Schaeps, Leon; Koper, Rob; Heyenrath, Stef 2011-02-27T21:09:35+01:00 desirability evaluation learning path specification pragmatic quality usability Assessing the Learning Path Specification: a Pragmatic Quality Approach Berlanga, Adriana J. Finders, Anton Herder, Eelco Martens, Harry Hermans, Henry Vogten, Hubert Gallardo, Javier Melero Janssen, José Schaeps, Leon Koper, Rob Heyenrath, Stef desirability,evaluation,learning path specification,pragmatic quality,usability JUCS - Journal of Universal Computer Science Vol. 16 2010 12 3191-3209 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_20/towards_a_theory_of Conceptual modelling is a widely applied practice and has led to a large body of knowledge on constructs that might be used for modelling and on methods that might be useful for modelling. It is commonly accepted that database application development is based on conceptual modelling. It is however surprising that only very few publications have been published on a <I>theory of conceptual modelling</I>.</P> <P><I>Modelling</I> is typically supported by languages that are well-founded and easy to apply for the description of the application domain, the requirements and the system solution. It is thus based on a theory of modelling constructs. At the same time, modelling incorporates a description of the application domain and a prescription of requirements for supporting systems. It is thus based on methods of <I>application domain gathering</I>. Modelling is also an engineering activity with engineering steps and engineering results. It is thus <I>engineering</I>. The first facet of modelling has led to a huge body of knowledge. The second facet is considered from time to time in the scientific literature. The third facet is underexposed in the scientific literature.</P> <P>This paper aims in developing principles of conceptual modelling. They cover modelling constructs as well as modelling activities as well as modelling properties. We first clarify the notion of conceptual modelling. Principles of modelling may be applied and accepted or not by the modeler. Based on these principles we can derive a theory of conceptual modelling that combines foundations of modelling constructs, application capture and engineering.</P> <P>A general theory of conceptual modelling is far too comprehensive and far too complex. It is not yet visible how such a theory can be developed. This paper therefore aims in introducing a framework and an approach to a general theory of conceptual modelling. We are however in urgent need of such a theory. We are sure that this theory can be developed and use this paper for the introduction of the main ingredients of this theory. Thalheim, Bernhard 2011-01-31T10:32:54+01:00 conceptual modelling general theory of models modelling modelling act(ivity) principles of models and modelling Towards a Theory of Conceptual Modelling Thalheim, Bernhard conceptual modelling,general theory of models,modelling,modelling act(ivity),principles of models and modelling JUCS - Journal of Universal Computer Science Vol. 16 2010 11 3102-3137 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_19/authoring_and_delivering_personalised This paper examines the personalization of online training simulations which are a key modern approach in computer aided education. More specifically it focuses on the difficulties involved in authoring personalized training simulations. The composition of such systems is very difficult which has hampered their wide spread adoption [Joolingen, 03]. Presently adaptive training simulations can only be authored by programmers working closely with subject matter experts. One of the key ways for adaptive simulations to increase their popularity in online eLearning [Wade, 09] is to reduce the effort and technical skills required by authors in their development. We argue that personalized online simulations need to be composed by subject matter experts, inexpensively and quickly. This paper details the twin challenges in composing content for both educational simulations and personalization. It also describes ACTSim, a new and unique composition tool that supports the rapid development of personalized training simulations. In particular ACTSim focuses on situational simulations for inter personal dialogue, so called soft skills. This paper concludes with a series of evaluations of the composition tool and of courses developed using the composition tool. Gaffney, Conor; Dagger, Declan; Wade, Vincent 2011-01-27T15:29:13+01:00 adaptive authoring simulation soft skills Authoring and Delivering Personalised Simulations — an Innovative Approach to Adaptive eLearning for Soft Skills Gaffney, Conor Dagger, Declan Wade, Vincent adaptive,authoring,simulation,soft skills JUCS - Journal of Universal Computer Science Vol. 16 2010 10 2780-2800 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_19/authoring_of_probabilistic_sequencing One of the difficulties that self-directed learners face on their learning process is choosing the right learning resources. One of the goals of adaptive educational systems is helping students in finding the best set of learning resources for them. Adaptive systems try to infer the students' characteristics and store them in a user model whose information is used to drive the adaptation. However, the information that can be acquired is always limited and partial. In this paper, the use of Bayesian networks is proposed as a possible solution to adapt the sequence of activities to students. There are two research questions that are answered in this paper: whether Bayesian networks can be used to adaptively sequence learning material, and whether such an approach permits the reuse of learning units created for other systems. A positive answer to both question is complemented with a case study that illustrates the details of the process. Kloos, Carlos Delgado; Fernandez-Panadero, Carmen; Mayor-Berzal, Jaime; Gutierrez-Santos, Sergio 2011-01-27T15:29:07+01:00 Bayesian networks adaptive educational hypermedia sequencing Authoring of Probabilistic Sequencing in Adaptive Hypermedia with Bayesian Networks Kloos, Carlos Delgado Fernandez-Panadero, Carmen Mayor-Berzal, Jaime Gutierrez-Santos, Sergio Bayesian networks,adaptive educational hypermedia,sequencing JUCS - Journal of Universal Computer Science Vol. 16 2010 10 2801-2820 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_19/a_tool_for_managing Intelligent Tutoring Systems (ITSs) constitute a popular type of intelligent educational systems. Domain Knowledge (DK) is a basic part of an ITS and usually includes information about the concepts the ITS is dealing with and the teaching material itself. The teaching material consists of a set of learning objects (LOs). A LO is described by a data set called its metadata. Concepts are usually organized in a network, called a concept network (or map). Each concept is associated with a number of LOs. Existing tools for managing DK mainly deal with either LOs or concepts, but not with connecting them. In this paper, we present a tool for managing both types of information in DK: creating and editing a concept network and LO metadata as well as connecting them. Additionally, the tool can produce corresponding XML descriptions for each LO metadata. Finally, it provides facilities for helping tutors in organizing and composing their lessons. A small scale evaluation has shown more than satisfactory acceptability of the tool. Hatzilygeroudis, Ioannis; Garofalakis, John; Kyriakou, Panayiotis 2011-01-27T15:28:57+01:00 Domain Knowledge management Intelligent Tutoring Systems Learning Objects management Lesson organization A Tool for Managing Domain Knowledge and Helping Tutors in Intelligent Tutoring Systems Hatzilygeroudis, Ioannis Garofalakis, John Kyriakou, Panayiotis Domain Knowledge management,Intelligent Tutoring Systems,Learning Objects management,Lesson organization JUCS - Journal of Universal Computer Science Vol. 16 2010 10 2841-2861 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_19/model_driven_transformation_and Authoring of Adaptive Educational Hypermedia is a complex activity requiring the combination of a range of design and validation techniques. We demonstrate how Adaptive Educational Hypermedia can be transformed into CAVIAr courseware validation models allowing for its validation. The model-based representation and analysis of different concerns and model-based mappings and transformations are key contributors to this integrated solution. We illustrate the benefits of Model Driven Engineering methodologies that allow for interoperability between CAVIAr and a well known Adaptive Educational Hypermedia framework. By allowing for the validation of Adaptive Educational Hypermedia, the course creator limits the risk of pedagogical problems in migrating to Adaptive Educational Hypermedia from static courseware. Pahl, Claus; Melia, Mark 2011-01-27T15:28:51+01:00 Adaptive e-learning Courseware Validation Courseware authoring Courseware construction Model-driven engineering Model-driven Transformation and Validation of Adaptive Educational Hypermedia using CAVIAr Pahl, Claus Melia, Mark Adaptive e-learning,Courseware Validation,Courseware authoring,Courseware construction,Model-driven engineering JUCS - Journal of Universal Computer Science Vol. 16 2010 10 2862-2881 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_19/a_method_for_supporting Group formation is a key issue in e-learning environments that make use of collaborative work to enhance student performance. While there are many ways to arrange students to work in cooperative groups, recent works have shown that learning styles offer good opportunities to organize students. Particularly, it seems the case that regarding learning styles, heterogeneous groups tend to perform better than groups formed by students with similar characteristics. This work addresses the issue of supporting the authors' task of forming effective learner groups to improve student and group performance. This support is provided through a supervised method which, backed by a visualization tool, is able to produce groups with a good level of heterogeneity. Moreover, this method is not time-consuming for teachers. Ortigosa, Alvaro; Paredes, Pedro; Rodriguez, Pilar 2011-01-27T15:28:46+01:00 Authoring Tool Collaborative Work Group Formation Learning Styles A Method for Supporting Heterogeneous-Group Formation through Heuristics and Visualization Ortigosa, Alvaro Paredes, Pedro Rodriguez, Pilar Authoring Tool,Collaborative Work,Group Formation,Learning Styles JUCS - Journal of Universal Computer Science Vol. 16 2010 10 2882-2901 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_17/developing_a_secure_mobile 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. Rosado, David G.; Fernández-Medina, Eduardo; López, Javier; Piattini, Mario 2011-01-03T11:12:13+01:00 UML extension Use Cases secure development secure mobile grid security Developing a Secure Mobile Grid System through a UML Extension Rosado, David G. Fernández-Medina, Eduardo López, Javier Piattini, Mario UML extension,Use Cases,secure development,secure mobile grid,security JUCS - Journal of Universal Computer Science Vol. 16 2010 09 2333-2352 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_16/usage_based_object_similarity Recommender systems are widely used online to support users in finding relevant information. They can be based on different techniques such as content-based and collaborative filtering. In this paper, we introduce a new way of similarity calculation for item-based collaborative filtering. Thereby we focus on the usage of an object and not on the object's users as we claim the hypothesis that similarity of usage indicates content similarity. To prove this hypothesis we use learning objects accessible through the MACE portal where students can query several architectural repositories. For these objects, we generate object profiles based on their usage monitored within MACE. We further propose several recommendation techniques to apply this usagebased similarity calculation in real systems. Schmitz, Hans-Christian; Niemann, Katja; Scheffel, Maren; Friedrich, Martin; Wolpers, Martin; Kirschenmann, Uwe 2010-12-03T09:05:23+01:00 attention metadata item-based collaborative filtering recommender systems Usage-based Object Similarity Schmitz, Hans-Christian Niemann, Katja Scheffel, Maren Friedrich, Martin Wolpers, Martin Kirschenmann, Uwe attention metadata,item-based collaborative filtering,recommender systems JUCS - Journal of Universal Computer Science Vol. 16 2010 08 2272-2290 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_16/user_context_and_personalized Nowadays, personalized education is a very hot topic in technology enhanced learning (TEL) research. To support students during their learning process, the first step consists in capturing the context in which they evolve. Users typically operate in a heterogeneous environment when learning, including learning tools such as Learning Management Systems and non-learning tools and services such as e-mails, instant messaging, or web pages. Thus, user attention in a given context defines the Contextualized Attention Metadata (CAM). Various initiatives and projects allow capturing CAMs in a knowledge workers' environment not only in the TEL area, but also in other domains like Knowledge Work Support, Personal Information Management and Information Retrieval. After reviewing main existing approaches according to some specific criteria that are of main interest for capturing and sharing user contexts, we present in this paper a framework able to gather CAMs produced by any tool or computer system. The framework is built on the Web-Based Enterprise Management (WBEM) standard dedicated to system, network and application management. Attention information specific to heterogeneous tools are represented as a unified and extensible structure, and stored into a central repository compliant with the above-mentioned standard. To facilitate access to this attention repository, we introduced a middleware layer composed of two dynamic services: the first service allows users to define the attention data they want to collect, whereas the second service is dedicated to receive and retrieve the traces produced by computer systems. An implementation for collecting and storing CAM data generated by the Ariadne Finder and Moodle validates our approach. Duval, Erik; Broisin, Julien; Verbert, Katrien; Vidal, Philippe; Butoianu, Valentin 2010-12-03T09:05:14+01:00 contextualized attention metadata technology enhanced learning User Context and Personalized Learning: a Federation of Contextualized Attention Metadata Duval, Erik Broisin, Julien Verbert, Katrien Vidal, Philippe Butoianu, Valentin contextualized attention metadata,technology enhanced learning JUCS - Journal of Universal Computer Science Vol. 16 2010 08 2252-2271 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_16/content_recommendation_in_aposdle One of the success factors of Work Integrated Learning (WIL) is to provide the appropriate content to the users, both suitable for the topics they are currently working on, and their experience level in these topics. Our main contributions in this paper are (i) overcoming the problem of sparse content annotation by using a network based recommendation approach called Associative Network, which exploits the user context as input; (ii) using snippets for not only highlighting relevant parts of documents, but also serving as a basic concept enabling the WIL system to handle text-based and audiovisual content the same way; and (iii) using the Web Tool for Ontology Evaluation (WTE) toolkit for finding the best default semantic similarity measure of the Associative Network for new domains. The approach presented is employed in the software platform APOSDLE, which is designed to enable knowledge workers to learn at work. Stern, Hermann; Kraker, Peter; Scheir, Peter; Hofmair, Philip; Kaiser, Rene; Lindstaedt, Stefanie N. 2010-12-03T09:04:58+01:00 associative networks multimedia information systems recommender systems work integrated learning Content Recommendation in APOSDLE using the Associative Network Stern, Hermann Kraker, Peter Scheir, Peter Hofmair, Philip Kaiser, Rene Lindstaedt, Stefanie N. associative networks,multimedia information systems,recommender systems,work integrated learning JUCS - Journal of Universal Computer Science Vol. 16 2010 08 2214-2231 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_16/the_3A_personalized_contextual This paper discusses the 3A recommender system that targets CSCL (computer-supported collaborative learning) and CSCW (computer-supported collaborative work) environments. The proposed system models user interactions in a heterogeneous graph. Then, it applies a personalized, contextual, and multi-relational ranking algorithm to simultaneously rank actors, activity spaces, and assets. The results of an empirical evaluation carried out on an Epinions dataset indicate that the proposed recommendation approach exploiting the trust and authorship networks performs better than user-based collaborative filtering in terms of recall. Salzmann, Christophe; Gillet, Denis; Helou, Sandy El 2010-12-03T09:04:43+01:00 CSCL CSCW Recommender systems algorithms design pagerank trust The 3A Personalized, Contextual and Relation-based Recommender System Salzmann, Christophe Gillet, Denis Helou, Sandy El CSCL,CSCW,Recommender systems,algorithms,design,pagerank,trust JUCS - Journal of Universal Computer Science Vol. 16 2010 08 2179-2195 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_15/simcon_a_tool_to The promise of smart buildings (SBs) is a safer more productive environment for users and a more operationally efficient building for owners. The automation of building function is highly dependent on sensing devices and Smart Building Applications(SBAs), which are often only evaluated in situ post deployment, making re-development costly. In this paper we explore our experiences developing a Simulated Context (SimCon) Model which currently supports taking information from a Virtual Reality (VR) SB and converting it into three types of location context to conduct early rapid evaluation of location based SBAs. This model is expressed using the Sensor Modelling Language (sensorML). It also explores the integration of this model into the Industry Foundation Classes (IFC) for modelling and simulating SBs. It also details usability evaluations of the SimConfig and SimConViz Tool for improving evaluation during the design phase of smart building development life cycle. Gibney, Alan; Lewis, Dave; O'Sullivan, Declan; O'Neill, Eleanor; McGlinn, Kris 2010-12-10T12:21:58+01:00 evaluation modelling simulation smart building applications SimCon: A Tool to Support Rapid Evaluation of Smart Building Application Design using Context Simulation and Virtual Reality Gibney, Alan Lewis, Dave O'Sullivan, Declan O'Neill, Eleanor McGlinn, Kris evaluation,modelling,simulation,smart building applications JUCS - Journal of Universal Computer Science Vol. 16 2010 07 1992-2018 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_13/information_support_services_for Companies in collaborative networks require intermediation to perform. The collaborative network forms the breeding environment for the configuration of a Virtual Enterprise that can handle a business request. This configuration task can be supported by IT services. For collaborative networks such as production networks focused on non-digital services and products we propose to assign specific intermediation tasks to a human network moderator supported by these IT services. The obvious support is targeted for the configuration of the Virtual Enterprise i.e. the search and selection from the available products, services, and competences found among the network participants. The configuration decision can jeopardize the network performance by harming the trust necessary to build new Virtual Enterprises. Through a further intermediation task trust can be inspired and promoted in the network. This article shows how the configuration is supported by a Decision Support Service and how a Transparency Support Service supports the downloading and acceptance of decisions in collaborative networks. The article outlines the IT supportive service system and exemplifies the use by a scenario example. Results on intermediation in collaborative networks can prove helpful for general service science problems. Thimm, Heiko; Rasmussen, Karsten Boye 2010-10-08T10:08:18+02:00 collaborative work decision support network moderation and intermediation organizational trust service science virtual organizations Information Support Services for Intermediation Tasks of Collaborative Networks Thimm, Heiko Rasmussen, Karsten Boye collaborative work,decision support,network moderation and intermediation,organizational trust,service science,virtual organizations JUCS - Journal of Universal Computer Science Vol. 16 2010 07 1776-1800 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_12/mobile_intelligence 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. Cai, Yang 2010-09-17T17:53:31+02:00 anomaly detection instinctive computing motion sensor network smart environment Mobile Intelligence Cai, Yang anomaly detection,instinctive computing,motion,sensor network,smart environment JUCS - Journal of Universal Computer Science Vol. 16 2010 06 1650-1665 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_12/an_agent_based_architecture 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. Espinoza, Adán N.; Saldaña, Diana; García-Vázquez, Juan Pablo; Rodríguez, Marcela D.; Tentori, Mónica E.; Andrade, Ángel G. 2010-09-17T17:53:21+02:00 artificial intelligence information interfaces and presentation knowledge representation formalisms and methods multiagents systems smart environments ubiquitous computing An Agent-based Architecture for Developing Activity-Aware Systems for Assisting Elderly Espinoza, Adán N. Saldaña, Diana García-Vázquez, Juan Pablo Rodríguez, Marcela D. Tentori, Mónica E. Andrade, Ángel G. artificial intelligence,information interfaces and presentation,knowledge representation formalisms and methods,multiagents systems,smart environments,ubiquitous computing JUCS - Journal of Universal Computer Science Vol. 16 2010 06 1500-1520 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_12/context_awareness_for_collaborative 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. Favela, Jesus; Navarro, Leandro; Damian-Reyes, Pedro; Messeguer, Roc 2010-09-17T17:52:35+02:00 Computer Supported Collaborative Learning (CSCL) context awareness ubiquitous computing Context Awareness for Collaborative Learning with Uncertainty Management Favela, Jesus Navarro, Leandro Damian-Reyes, Pedro Messeguer, Roc Computer Supported Collaborative Learning (CSCL),context awareness,ubiquitous computing JUCS - Journal of Universal Computer Science Vol. 16 2010 06 1556-1576 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_8/how_is_egovernment_progressing As ICT provide a lot of possibilities, high expectancies exist towards the electronic public service provision. All governments are increasingly establishing their e-strategies. Nevertheless, both in research as among practitioners, some questions are formulated towards the current approaches. E-government policy has to deal with two main challenges: how to offer new and better services for the same (or lower) budget and how to increase user uptake? The challenges relate to both the efficiency of e-government, as its effectiveness. In order to further develop e-government strategies, governments need a thorough knowledge base to (a) to evaluate their current ways of working and (b) to found their activities of the future. In this paper we consider trends in e-government measurement and we discuss ongoing research towards the development of an e-government monitor for the Belgian government. This monitor will consist of different types of information from various sources, providing the necessary knowledge for all stakeholders involved to underpin their current and future e-strategies. Verleye, Gino; Stragier, Jeroen; Verdegem, Pieter 2010-06-12T00:41:00+02:00 e-government measurement e-government monitor efficiency and effectiveness indicators policy How is e-Government Progressing? <br> A Data Driven Approach to E-government Monitoring Verleye, Gino Stragier, Jeroen Verdegem, Pieter e-government measurement,e-government monitor,efficiency and effectiveness,indicators,policy JUCS - Journal of Universal Computer Science Vol. 16 2010 04 1075-1088 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_6/entropy_optimization_of_social Recent work on social networks has tackled the measurement and optimization of these networks' robustness and resilience to both failures and attacks. Different metrics have been used to quantitatively measure the robustness of a social network. In this work, we design and apply a Genetic Algorithm that maximizes the cyclic entropy of a social network model, hence optimizing its robustness to failures. Our social network model is a scale-free network created using Barabási and Albert's generative model, since it has been demonstrated recently that many large complex networks display a scale-free structure. We compare the cycles distribution of the optimally robust network generated by our algorithm to that belonging to a fully connected network. Moreover, we optimize the robustness of a scale-free network based on the links-degree entropy, and compare the outcomes to that which is based on cycles-entropy. We show that both cyclic and degree entropy optimization are equivalent and provide the same final optimal distribution. Hence, cyclic entropy optimization is justified in the search for the optimal network distribution. Taniar, David; Mahdi, Khaled; Safar, Maytham; El-Sayed, Nosayba 2010-05-26T14:28:14+02:00 entropy evolutionary algorithm genetic algorithm social networks Entropy Optimization of Social Networks Using an Evolutionary Algorithm Taniar, David Mahdi, Khaled Safar, Maytham El-Sayed, Nosayba entropy,evolutionary algorithm,genetic algorithm,social networks JUCS - Journal of Universal Computer Science Vol. 16 2010 03 983-1003 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_4/performance_optimizations_for_daa With the spreading of embedded and mobile devices, public-key cryptography hasbecome an important feature for securing communication and protecting personal data. However, the computational requirements of public-key cryptosystems are often beyond the constraints em-bedded processors are bound to. This is especially true for cryptosystems that make heavy use of modular exponentiation like the Direct Anonymous Attestation scheme. The most popular al-gorithm for modular exponentiation is the Montgomery exponentiation based on sliding window technology. This technology offers several configuration options in order to get the best trade-offbetween the amount of precomputations and multiplications that are required for different exponentiation operands. Consequently, the optimum configuration and best parameters for receivingthe highest performance gain are of interest. In this paper, we analyse different approaches for improving the performance of modular exponentiations with respect to the DAA scheme on Javaenabled platforms. In particular, we analyse the optimal parameter setting for the Montgomery exponentiation and investigate how natively executed modular multiplications and modular re-ductions, with respect to a minimum of native code involved, can be integrated to improve the performance of mobile Java applications. Our experimental results show that the optimal setupof the Montgomery algorithm for a single modular exponentiation differs from the optimal setup used for the combination of all operations and operands used in the Direct Anonymous Attesta-tion scheme. We also show that it is possible to get an immense performance gain by executing small parts of critical arithmetic operations natively on the platform thereby, not reducing theflexibility of mobile Java code. Röck, Franz; Dietrich, Kurt 2010-05-09T09:01:31+02:00 DAA anonymous credentials remote attestation trusted computing Performance Optimizations for DAA Signatures on Java enabled Platforms Röck, Franz Dietrich, Kurt DAA,anonymous credentials,remote attestation,trusted computing JUCS - Journal of Universal Computer Science Vol. 16 2010 02 519-529 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_4/on_reliable_platform_configuration One of the most important use-cases of Trusted Computing is Remote Attestation. Itallows platforms to get a trustworthy proof of the loaded software and current configuration of certain remote platforms, thereby enabling them to make decisions about the remote platforms'trust status. Common concepts like Internet Protocol security or Transport Layer Security make these decisions based on shared secrets or certificates issued by third parties. Unlike remote at-testation, these concepts do not take the current configuration or currently loaded software of the platforms into account. Consequently, combining remote attestation and existing secure channelconcepts can solve the long lasting problem of secure channels that have to rely on insecure channel endpoints. Although this gap can now be closed by Trusted Computing, one important prob-lem remains unsolved: A platform's configuration changes everytime new software is loaded. Consequently, a reliable and in-time method to provide a proof for this configuration change -especially on multiprocess machines - is required to signal the platforms involved in the communication that a configuration change of the respectively other platform has taken place. Ourresearch results show that a simple reporting mechanism can be integrated into current Trusted Platform Modules and Transport Layer Security implementations with a few additional TrustedPlatform Modules commands and a few extensions to the TLS protocol. Dietrich, Kurt 2010-05-09T09:01:14+02:00 TLS platform configuration reporting remote attestation secure channels trusted computing On Reliable Platform Configuration Change Reporting Mechanisms for Trusted Computing Enabled Platforms Dietrich, Kurt TLS,platform configuration reporting,remote attestation,secure channels,trusted computing JUCS - Journal of Universal Computer Science Vol. 16 2010 02 507-518 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_16_3/enabling_personal_privacy_for 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. Zeidler, Andreas; Valdivielso, Carlos Fernandez; Klein, Cornel; Matias, Ignacio R.; Bagüés, Susana Alcalde 2010-04-22T15:51:06+02:00 personal privacy pervasive computing privacy architecture user manageability Enabling Personal Privacy for Pervasive Computing Environments Zeidler, Andreas Valdivielso, Carlos Fernandez Klein, Cornel Matias, Ignacio R. Bagüés, Susana Alcalde personal privacy,pervasive computing,privacy architecture,user manageability JUCS - Journal of Universal Computer Science Vol. 16 2010 02 341-371 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_15_15/managing_security_and_its Due to the growing dependence of information society on Information and Communication Technologies, the need to protect information is getting more and more important for enterprises. In this context, Information Security Management Systems (ISMSs), have arisen for supporting the processes and systems for effectively managing information security. The fact of having these systems available has become more and more vital for the evolution of Small and Medium-Sized Enterprises (SMEs), but however, this type of enterprises have special characteristics which make it difficult for them the correct deployment of ISMSs. In this article, we show the methodology that we have created for the development, implementation and maintenance of ISMSs, adapted for the needs and resources available for SMEs. This approach is being directly applied to real case studies and thus, we are obtaining a constant improvement in its application. Parra, Antonio Santos-Olmo; Rosado, David G.; Sánchez, Luís Enrique; Piattini, Mario 2010-11-25T11:07:31+01:00 ISMS SME security system Managing Security and its Maturity in Small and Medium-sized Enterprises Parra, Antonio Santos-Olmo Rosado, David G. Sánchez, Luís Enrique Piattini, Mario ISMS,SME,security system JUCS - Journal of Universal Computer Science Vol. 15 2009 09 3038-3058 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_15_14/a_web_decision_support Collaborative Filtering has been widely used in Recommender Systems helping customers of e-shops to find out items matching their requirements in huge or complex search spaces. There exist many commercial applications that show the utility of these systems, especially in e-commerce whose features and good performance obtained has driven us to consider their application in a specific domain as <I>Academic Orientation</I>, in order to support students' decisions through their academic journey. We propose the use of the ideas behind the Collaborative Recommender Systems to develop a Web-based Decision Support System (Web-DSS) for Academic Orientation that analyze the students' skills, attitudes, preferences, etc., and then compute relevant information to support their decisions concerning their academic future. Furthermore, we shall study the performance of such techniques in Academic Orientation by using a dataset gathered from various Secondary and High Schools in Spain. <I>OrieB</I>, a web-DSS for academic orientation is then presented. Castellano, Emilio J.; Martínez, Luis 2010-11-15T11:10:26+01:00 academic orientation collaborative filtering decision support systems recommender systems A Web-Decision Support System based on Collaborative Filtering for Academic Orientation. <br>Case Study of the Spanish Secondary School. Castellano, Emilio J. Martínez, Luis academic orientation,collaborative filtering,decision support systems,recommender systems JUCS - Journal of Universal Computer Science Vol. 15 2009 08 2786-2807 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_15_13/applications_of_cerebellar_model The atmospheric disturbances affect not only flying qualities of an airplane but also flight safety. According to flight records, most aircraft accidents occurred during final approach or landing. If the flight conditions are beyond the preset envelope, the automatic landing system (ALS) is disabled and the pilot takes over. An inexperienced pilot may not be able to guide the aircraft to a safe landing at the airport when wind disturbance is encountered. This study proposes different cerebellar model articulation controllers (CMAC) to improve the performance of conventional ALS. A CMAC with general basis function (CMAC-GBF) and a type-2 fuzzy CMAC (FCMAC) are applied to construct intelligent landing system which can guide the aircraft to a safe landing in severe wind turbulence environment. Lee, Chia-Lin; Juang, Jih-Gau 2010-11-24T16:39:36+01:00 CMAC Fuzzy System Intelligent Landing System PID control Turbulence Applications of Cerebellar Model Articulation Controllers to Intelligent Landing System Lee, Chia-Lin Juang, Jih-Gau CMAC,Fuzzy System,Intelligent Landing System,PID control,Turbulence JUCS - Journal of Universal Computer Science Vol. 15 2009 07 2586-2607 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_15_13/a_multiagent_system_for This paper presents the architecture of a multiagent system based on new OPC Unified Architecture (UA) technology for hierarchical control and monitoring of a complex process control system. This architecture is proposed with utilization of the OPC technology, which contains both a continuous-event component and a discreteevent component by incorporating XML for the negotiation and cooperation with the multiagent system's environments. The practical applications of the proposed architecture are provided and the discussion demonstrates that the proposed architecture is both reliable and effective for applying to multiagent-based complex control system applications. Yoo, Dae-Seung; Shin, Jun-Chol; Yi, Myeong-Jae; Tan, Vu Van 2010-11-24T16:39:15+01:00 OPC XML hierarchical control monitoring multiagent process control unified architecture A Multiagent System for Hierarchical Control and Monitoring Yoo, Dae-Seung Shin, Jun-Chol Yi, Myeong-Jae Tan, Vu Van OPC,XML,hierarchical control,monitoring,multiagent,process control,unified architecture JUCS - Journal of Universal Computer Science Vol. 15 2009 07 2485-2505 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_15_13/interactive_learning_of_independent Efficient response to natural disasters has an increasingly important role in limiting the toll on human life and property. The work we have undertaken seeks to improve existing models by building a Decision Support System (DSS) of resource allocation and planning for natural disaster emergencies in urban areas. A multi-agent environment is used to simulate disaster response activities, taking into account geospatial, temporal and rescue organizational information. The problem we address is the acquisition of situated expert knowledge that is used to organize rescue missions. We propose an approach based on participatory design and interactive learning which incrementally elicits experts' preferences by online analysis of their interventions with rescue simulations. An additive utility functions are used, assuming mutual preferential independence between decision criteria, as a preference for the elicitation process. The learning algorithm proposed refines the coefficients of the utility function by resolving incremental linear programming. For testing our algorithm, we run rescue scenarios of ambulances saving victims. This experiment makes use of geographical data for the Ba-Dinh district of Hanoi and damage parameters from well-regarded local statistical and geographical resources. The preliminary results show that our approach is initially confident in solving this problem. Boucher, Alain; Drogoul, Alexis; Zucker, Jean-Daniel; Chu, Thanh-Quang 2010-11-24T16:38:54+01:00 decision support system disaster response interactive learning multi-agent simulation multi-criteria decision making participatory design preference elicitation utility function Interactive Learning of Independent Experts' Criteria for Rescue Simulations Boucher, Alain Drogoul, Alexis Zucker, Jean-Daniel Chu, Thanh-Quang decision support system,disaster response,interactive learning,multi-agent simulation,multi-criteria decision making,participatory design,preference elicitation,utility function JUCS - Journal of Universal Computer Science Vol. 15 2009 07 2701-2725 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_15_12/a_joint_web_resource Personalized recommendation is valuable in various web applications, such as e-commerce, music sharing, and news releasing, etc. Most existing recommendation methods require users to register and provide their private information before gaining access to any services, whereas a majority of users are reluctant to do so, which greatly limits the range of application of such recommendation methods. In the non-register environments, the only available information is the content or attributes of resources and the click-through chains of user sessions, so that many recommendation methods fail to work effectively due to the rating sparsity [Adomavicius and Tuzhilin, 2005] and illegibility of user identity, collaborative filtering [Goldberg et al. 1992] is an example of this case. In this paper we propose a joint recommendation method combining together two approaches, namely the domain category tree and the associate graph, to make full use of all available information. Further, an associate graph propagation method is designed to improve the traditional associate filtering method by integrating additional graphical considerations into them. Experiment results show that our method outperforms either the single category tree approach or the single associate graph approach, and it can provide acceptable recommendation services even in the non-register environment. Yang, Laurence T.; Weng, Linkai; Zhong, Ming; Tian, Pengwei; Zhang, Yaoxue; Zhou, Yuezhi 2010-11-24T15:42:47+01:00 category tree graph propagation personalized recommendation personalized service A Joint Web Resource Recommendation Method based on Category Tree and Associate Graph Yang, Laurence T. Weng, Linkai Zhong, Ming Tian, Pengwei Zhang, Yaoxue Zhou, Yuezhi category tree,graph propagation,personalized recommendation,personalized service JUCS - Journal of Universal Computer Science Vol. 15 2009 06 2387-2408 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_15_9/applying_reputation_mechanisms_in Communities of Practice (CoP) are groups of people sharing practices, interests, and work objectives. In the virtual world, however, it is difficult to trust contributions from people we do not know, because of the variety of information sources and behaviors. In this context, a Reputation Model for CoP (ReCoP) was developed. This paper presents a case study that evaluates one ReCoP mechanism: the degree of agreement among members in evaluating artifacts shared within the community. Data was extracted from a real scenario, and the results provide useful feedback for further studies and improvements in implementing the model. Cruz, Claudia C. P.; Motta, Claudia L. R.; Santoro, Flávia Maria; Elia, Marcos 2010-11-24T12:19:26+01:00 community of practice recommender systems reputation systems Applying Reputation Mechanisms in Communities of Practice: A Case Study Cruz, Claudia C. P. Motta, Claudia L. R. Santoro, Flávia Maria Elia, Marcos community of practice,recommender systems,reputation systems JUCS - Journal of Universal Computer Science Vol. 15 2009 05 1886-1906 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_15_9/an_application_of_the Dynamic pattern analysis refers to analyzing the relationship of spatial patterns at different time points. Traditional spatial pattern analysis such as data clustering can find the spatial patterns extant at a geographical location at a particular time point but failing to identify spatial dynamics, or changes that occur over time in a particular place. In this paper, we present a dynamic pattern analysis framework, the <I>DPA framework</I>. This framework allows user to identify three types of dynamic patterns in spatial-temporal data: 1) similar spatial patterns at different time points, 2) interactive relationship between two geographical locations as a result of a specific reason and 3) frequent association rules related to particular types of events, geographical locations, and time points. To evaluate the proposed framework, we used it to analyze a set of reported crime data for a district of Hong Kong and compared the identified patterns with some expectations of field experts and prior empirical studies for this kind of data and patterns. In line with expert predictions, we found strong correlations between school holidays and crime clusters. On the contrary, in our data set, we could not find obvious seasonal dependency. These findings are corroborated by related empirical crime studies. Li, Junco; Leong, Kelvin; Chan, Stephen; Ng, Vincent 2010-11-24T12:19:15+01:00 CSCW crime analysis spatial-temporal data mining An Application of the Dynamic Pattern Analysis Framework to the Analysis of Spatial-Temporal Crime Relationships Li, Junco Leong, Kelvin Chan, Stephen Ng, Vincent CSCW,crime analysis,spatial-temporal data mining JUCS - Journal of Universal Computer Science Vol. 15 2009 05 1852-1870 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_15_9/mc_supporter_flexible_mobile 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. Zurita, Gustavo; Baloian, Nelson 2010-11-24T12:19:09+01:00 Computer Supported Collaborative Llearning (CSCL) mobile learning social interactions MC-Supporter: Flexible Mobile Computing Supporting Learning though Social Interactions Zurita, Gustavo Baloian, Nelson Computer Supported Collaborative Llearning (CSCL),mobile learning,social interactions JUCS - Journal of Universal Computer Science Vol. 15 2009 05 1833-1851 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_15_7/semantic_spiral_timelines_used This article presents Semantic Spiral Timelines (SST) as an interactive visual tool aimed at the exploration and analysis of additional academic information stored in current e-learning platforms. Despite the development of contents specifically for these platforms, and in spite of the various features they provide, knowledge of the actual use made by individual participants is emerging as an unavoidable necessity, so as to ensure proper operation and effective use of e-learning platforms. SST supports the discovery of temporal patterns by incorporating an innovative highly interactive visual representation, which can be explored at various levels. This tool makes it possible to assess, at first glance, the use of the e-learning platform during the development of courses; one can also perceive how it is used by class participants. Then, through different interaction mechanisms, it is possible for students and professors to uncover specific details about courses, which would otherwise remain hidden. Aguilar, Diego Alonso Gómez; García-Peñalvo, Francisco J.; Therón, Roberto 2011-01-21T11:59:03+01:00 Moodle e-learning spiral timeline visualization Semantic Spiral Timelines Used as Support for e-Learning Aguilar, Diego Alonso Gómez García-Peñalvo, Francisco J. Therón, Roberto Moodle,e-learning,spiral,timeline,visualization JUCS - Journal of Universal Computer Science Vol. 15 2009 04 1526-1545 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_15_7/learning_to_program_with Learning to program is an important subject for students of Computer Science. Mentoring these students is a time-consuming and complex task. In this paper, we present a learning and tutoring environment that integrates task/solution delivery, assessment support and tutor's annotations, by extending Eclipse to a "Real World Integrated Development Environment". We will present a distributed system that uses Tuple Space architecture to integrate Eclipse with an evaluation module and a hand-writing annotation feature. Giemza, Adam; Molina, Ana I.; Jurado, Francisco; Hoppe, H. Ulrich; Bollen, Lars; Ortega, Manuel; Redondo, Miguel A. 2011-01-21T11:58:40+01:00 intelligent tutoring system learning programming Learning to Program with COALA, a Distributed Computer Assisted Environment Giemza, Adam Molina, Ana I. Jurado, Francisco Hoppe, H. Ulrich Bollen, Lars Ortega, Manuel Redondo, Miguel A. intelligent tutoring system,learning programming JUCS - Journal of Universal Computer Science Vol. 15 2009 04 1472-1485 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_15_5/a_neural_network_based Pervasive smart computing environments make people get accustomed to convenient and secure services. The overall goal of this research is to classify vehicles along the I215 freeway in Salt Lake City, USA. This information will be used to predict future roadway needs and the expected life of a roadway. The classification of vehicles will be performed by a synthesis of multiple sets of features. All feature sets have not yet been determined; however, one such set will be the reduced wavelet transform of the image of a vehicle. In order to use such a feature, it is necessary that the image be normalized with respect to size, position, and so on. For example, a car in the right most lane in an image will appear smaller than one in the left most lane, because the right most lane is closest to the camera. Likewise, a vehicle's size will vary depending on where in a lane its image is captured. In our case, the image capture area for each lane is approximately 100 feet of roadway. A goal of this paper is to normalize the image of a vehicle so that regardless of its lane or position in a lane, the features will be approximately the same. The wavelet transform itself will not be used directly for recognition. Instead, it will be input to a neural network and the output of the neural network will be one element of the feature set used for recognition. Cooley, Donald; He, Jing; Park, Jong Hyuk; Xiong, Naixue; Li, Yingshu 2010-11-18T10:28:28+01:00 Neural Network Normalization Recognition Vehicle classification Wavelet Wavelet transform image processing A Neural Network Based Vehicle Classification System for Pervasive Smart Road Security Cooley, Donald He, Jing Park, Jong Hyuk Xiong, Naixue Li, Yingshu Neural Network,Normalization,Recognition,Vehicle classification,Wavelet,Wavelet transform,image processing JUCS - Journal of Universal Computer Science Vol. 15 2009 03 1119-1142 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_15_5/security_analysis_of_the 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. Lee, Changhoon; Kim, Jongsung; Hong, Seokhie; Lee, Yang-Sun 2010-11-18T10:27:56+01:00 Block Cipher CHESS-64 Data-Dependent Operation Data-Dependent Permutation Differential Cryptanalysis Related-Key Attack Security Analysis of the Full-Round CHESS-64 Cipher Suitable for Pervasive Computing Environments Lee, Changhoon Kim, Jongsung Hong, Seokhie Lee, Yang-Sun Block Cipher,CHESS-64,Data-Dependent Operation,Data-Dependent Permutation,Differential Cryptanalysis,Related-Key Attack JUCS - Journal of Universal Computer Science Vol. 15 2009 03 1007-1022 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_15_4/multilayer_ensemble_pruning_via Recently, classifier ensemble methods are gaining more and more attention in the machine-learning and data-mining communities. In most cases, the performance of an ensemble is better than a single classifier. Many methods for creating diverse classifiers were developed during the past decade. When these diverse classifiers are generated, it is important to select the proper base classifier to join the ensemble. Usually, this selection process is called pruning the ensemble. In general, the ensemble pruning is a selection process in which an optimal combination will be selected from many existing base classifiers. Some base classifiers containing useful information may be excluded in this pruning process. To avoid this problem, the multilayer ensemble pruning model is used in this paper. In this model, the pruning of one layer can be seen as a multimodal optimization problem. A novel multi-sub-swarm particle swarm optimization (MSSPSO) is used here to find multi-solutions for this multilayer ensemble pruning model. In this model, each base classifier will generate an oracle output. Each layer will use MSSPSO algorithm to generate a different pruning based on previous oracle output. A series of experiments using UCI dataset is conducted, the experimental results show that the multilayer ensemble pruning via MSSPSO algorithm can improve the generalization performance of the multi-classifiers ensemble system. Besides, the experimental results show a relationship between the diversity and the pruning technique. Zhang, Jun; Chau, Kwok-Wing 2010-11-15T15:59:57+01:00 classifier ensemble ensemble pruning multi-layer ensemble model particle swarm optimization Multilayer Ensemble Pruning via Novel Multi-sub-swarm Particle Swarm Optimization Zhang, Jun Chau, Kwok-Wing classifier ensemble,ensemble pruning,multi-layer ensemble model,particle swarm optimization JUCS - Journal of Universal Computer Science Vol. 15 2009 02 840-858 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_15_4/fingerprinting_lexical_contexts_over In this paper a novel technique for identifying lexical contexts in web resources is presented. The basic idea is to consider web site anchortexts as lexicalized descriptions of an individual ontology organized in the form of a graph of concept words. In the search for peculiar semantic patterns, the concept of web minutia (transposed from the forensic domain) is introduced. The proposed technique consists in searching for web minutiae in the analyzed web sites by means of a golden ontology. Web minutiae act as fingerprints for context-specific web resources; in this sense they are a powerful computational tool to identify and categorize the Web. The WordNet database has been used as golden ontology for our experiments on English web documents. WordNet allows for indexing and retrieving word senses and inter-word taxonomical relations like hyponymy and hypernymy. It has proven to be an efficient mediator between web ontologies and context-dependent taxonomies. Our experiments have been carried out on a preliminary data set of several tens of thousand links taken by web sites of thirteen UK universities. Preliminary results seem to confirm the ability of web minutiae to identify lexical contexts across the Web. Soldo, Domenico; Calabrese, Marco; Lecce, Vincenzo Di 2010-11-15T15:59:45+01:00 Semantic Web Web Mining WordNet golden ontology knowledge discovery minutia Fingerprinting Lexical Contexts over the Web Soldo, Domenico Calabrese, Marco Lecce, Vincenzo Di Semantic Web,Web Mining,WordNet,golden ontology,knowledge discovery,minutia JUCS - Journal of Universal Computer Science Vol. 15 2009 02 805-825 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_15_3/ds_rbac_dynamic Besides the well established access control models, Discretionary Access Control (DAC) and Mandatory Access Control (MAC), the policy neutral Role Based Access Control (RBAC) is gaining increasingly momentum. An important step towards a wide acceptance of RBAC has been achieved by the standardization of RBAC through the American National Standards Institute (ANSI) in 2004.</P> <P>While the concept of sessions specified in the ANSI RBAC standard allows for differentiated role selections according to tasks that have to be performed by users, it is very likely that more roles will be activated in a session than are effectively needed to perform the intended activity. Dynamic Sessions in RBAC (DS RBAC) is an extension to the existing RBAC ANSI standard that dynamically deactivates roles in a session if they are not exercised for a certain period of time. This allows for the selection of an outer-shell of possibly needed permissions at the initation of a session through a user, while adhering to the principle of least privilege by automatically reducing the effective permission space to those roles really exercised in the session.</P> <P>Analogous to the working set model known from virtual memory, only the minimal roles containing permissions recently exercised by the user are left in a session in the DS RBAC model. If the user tries to access a role that has aged out due to inactivity, a role fault occurs. A role fault can be resolved by the role fault handler that is responsible for re-activating the expired role. As will be presented in this paper, role re-activation may be subject to constraints that have to be fulfilled by the user in order to re-access the aged role. Praher, Christian; Mühlbacher, Jörg R. 2010-11-15T15:16:14+01:00 ANSI RBAC Role Based Access Control least privilege security session DS RBAC - Dynamic Sessions in Role Based Access Control Praher, Christian Mühlbacher, Jörg R. ANSI RBAC,Role Based Access Control,least privilege,security,session JUCS - Journal of Universal Computer Science Vol. 15 2009 02 538-554 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_15_3/knowledge_sharing_and_collaborative In this paper we propose a classification and systematic description structure based on the pattern paradigm for interaction scripts in Second Life that aim at facilitating on the one side knowledge sharing and knowledge integration in groups, and on the other side knowledge creation in formal and informal ways. We present 13 examples of interaction patterns, a description structure to formalize them, and classify them into four classes according to their design effort and added value. Based on this classification we distinguish among sophisticated 3D collaboration patterns, seamless patterns, decorative patterns, and pseudo patterns. Schmeil, Andreas; Eppler, Martin J. 2010-11-15T15:15:47+01:00 MUVE Second Life collaboration patterns knowledge sharing online collaboration virtual worlds Knowledge Sharing and Collaborative Learning in Second Life: A Classification of Virtual 3D Group Interaction Scripts Schmeil, Andreas Eppler, Martin J. MUVE,Second Life,collaboration patterns,knowledge sharing,online collaboration,virtual worlds JUCS - Journal of Universal Computer Science Vol. 15 2009 02 665-677 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_15_3/web_20_adoption_by This paper presents findings from the development process of a general innovation framework for an ongoing Nordic R&D project on e-business and media. It focuses on the current state of the Danish news media sector and the conclusions we can draw from the "Web 2.0 activity" of the Danish newspapers. The paper concludes that the Web 2.0 implies the need for fundamental re-thinking of the business models of the news media sector and for developing a new framework for business modelling for this sector. Rasmussen, Leif Bloch; Bjørn-Andersen, Niels; Rasmussen, Soley 2010-11-15T15:15:32+01:00 Web 2.0 Wikinomics business models heterarchy new media newspapers social media Web 2.0 Adoption by Danish Newspapers - Urgent Need for New Business Models? Rasmussen, Leif Bloch Bjørn-Andersen, Niels Rasmussen, Soley Web 2.0,Wikinomics,business models,heterarchy,new media,newspapers,social media JUCS - Journal of Universal Computer Science Vol. 15 2009 02 692-703 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_14_19/sharp_online_an_adaptive In this article we present the development of a web application called SHARP Online: An Adaptive Hypermedia System Applied to Mathematical Problem Solving. The pedagogical basis of this application is found in the support techniques for heuristic learning in mathematical problem solving developed according to the Schoenfeld model. The adaptivity of this tool is achieved by way of the utilization of an adaptive algorithm which has been developed for it and is described in this article. This algorithm implements mechanisms that make it possible for the user to construct mathematical knowledge adaptively using training methods. This application also provides the teacher with the following complete set of tools for managing the entire process: the inclusion of contents through a collaborative application with support; a shared work space; the adaptivity of the algorithm variables; and the supervision of the students' progress, etc. through specific modules. This application was originally developed for educational contexts in the area of teaching mathematics, and therefore includes a module for editing and visualizing mathematical formulas for a Web environment. Gil, Ana-Belén; García-Peñalvo, Francisco J.; Rodríguez, Raquel; López, Ricardo 2009-08-06T15:11:30+02:00 adaptive hypermedia heuristic thought interactive learning environments teaching/learning strategies user-computer interaction SHARP Online: An Adaptive Hypermedia System Applied to Mathematical Problem Solving Gil, Ana-Belén García-Peñalvo, Francisco J. Rodríguez, Raquel López, Ricardo adaptive hypermedia,heuristic thought,interactive learning environments,teaching/learning strategies,user-computer interaction JUCS - Journal of Universal Computer Science Vol. 14 2008 11 3099-3113 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_14_19/a_model_of_interaction This paper summarizes a model of interaction for CVEs inspired by the process followed in human communication in the real world, detailing both the main elements and the communication process itself. The model proposed copies some properties of the real world communication but also allows the easy integration of Task Analysis to the design of CVEs, helping the developer in the design of the application. Furthermore, some of the benefits that the usage of this model brings to the user are also shown. Finally, some implementation details of a prototype supporting the described model are given. This prototype is used all along the paper to illustrate the explanation of some parts of the model. García, Arturo S.; Martínez, Diego; Martínez, Jonatan; Molina, José P.; Gonzalez, Pascual 2009-08-06T15:11:19+02:00 collaborative virtual environments human-computer interaction virtual reality A Model of Interaction for CVEs Based on the Model of Human Communication García, Arturo S. Martínez, Diego Martínez, Jonatan Molina, José P. Gonzalez, Pascual collaborative virtual environments,human-computer interaction,virtual reality JUCS - Journal of Universal Computer Science Vol. 14 2008 11 3071-3084 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_14_17/creating_adaptive_elearning_board The use of digital games in education is well documented in the literature. They have been used in preschool, K-12, the university. A specific type of digital games is board games. Adding board games to the educational process can lead to an interactive stimulating learning experience. With a board game, players often learn from one another while at the same time having fun in a competitive environment. In this paper we propose the "ELG" game, an e-learning board game that adopts the basic elements of a racing board game but fosters students' creativity, problem-solving skills, and imagination as students are trying to reach the end by improving their performance in a variety of learning activities. The innovative feature of the ELG is that it offers an adaptive authoring tool that enables teachers to customize their games according to the needs, interests and motives of students. The teacher enters hierarchically categorized learning activities according to the learning goals of a course, sets the rules and assesses the learning progress easily and simply. Students participate in a discovery or exploration trying to reach the goals. After attaining them their level of activities is upgraded and they are challenged to reach the next learning goal. The dice in ELG is not randomized but controlled by the teachers in order that they can customize adaptive learning rules. The educational benefits of exploiting ELG in the learning process is that the teacher can define the levels of difficulty according to the students' needs and interests, facilitate and monitor the learning rate of each student, combine a variety of evaluation techniques, and address potential learning problems in a timely manner. Retalis, Symeon 2009-08-04T21:34:50+02:00 adaptive environments authoring tools e-learning game based learning Creating Adaptive e-Learning Board Games for School Settings Using the ELG Environment Retalis, Symeon adaptive environments,authoring tools,e-learning,game based learning JUCS - Journal of Universal Computer Science Vol. 14 2008 09 2897-2908 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_14_17/authoring_courses_with_rich This paper describes the process of translating an adaptive sequencing strategy designed using Sequencing Graphs to the semantics of IMS Learning Design. The relevance of this contribution is twofold. First, it combines the expressive power and flexibility of Sequencing Graphs, and the interoperability capabilities of IMS. Second, it shows some important limitations of IMS specifications (focusing on Learning Design) for the sequencing of learning activities. Pardo, Abelardo; Kloos, Carlos Delgado; Gutierrez-Santos, Sergio 2009-08-04T21:34:10+02:00 IMS Learning Design sequencing sequencing graph translation Authoring Courses with Rich Adaptive Sequencing for IMS Learning Design Pardo, Abelardo Kloos, Carlos Delgado Gutierrez-Santos, Sergio IMS Learning Design,sequencing,sequencing graph,translation JUCS - Journal of Universal Computer Science Vol. 14 2008 09 2819-2839 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_14_17/its_domain_modelling_with Authoring ITS domain models is a difficult task requiring many skills. We explored whether modeling ontology reduces the problem by giving the students of an e-learning summer school the task of developing the model for a simple domain in under sixty minutes using ontology. Some students also used our tool to develop a complete tutor in around eight hours, which is much faster than they could be expected to author the system without the tool. The results suggest this style of authoring can lead to very rapid ITS development. We further extend the ontological approach with domain schema: high-level abstractions that describe the semantics of the domain model for a class of domains. Using domain schema reduces the authoring effort to one of describing only those aspects that are unique to this particular domain, and enables the ontology-based approach to model domains with different semantic requirements. Mitrovic, Antonija; Martin, Brent; Suraweera, Pramuditha 2009-08-04T21:33:37+02:00 authoring systems constraint-based modeling domain models intelligent tutoring systems ontology ITS Domain Modelling with Ontology Mitrovic, Antonija Martin, Brent Suraweera, Pramuditha authoring systems,constraint-based modeling,domain models,intelligent tutoring systems,ontology JUCS - Journal of Universal Computer Science Vol. 14 2008 09 2758-2776 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria http://www.jucs.org/jucs_14_1/the_remote_control_approach In this article we present an architecture for the integration of tutoring approaches and process scaffolds into existing collaborative applications. The architecture allows to combine existing research on explicit representations of collaborative learning processes with the availability of existing and tested collaborative learning environments. The architecture allows to control the learning environments either by a human or a pedagogic agent and thus enables adaptation of the tools to the current state of the learning process. Both types of tutors are using a so-called remote control component using the same set of control primitives. To prove the soundness of the architecture and the flexibility of its implementation two example scenarios are shown that use IMS LD learning process definitions with the Coppercore learning design engine controlling our collaborative environments. Harrer, Andreas; Wichmann, Astrid; Malzahn, Nils 2008-09-18T12:59:07+02:00 collaboration scripts integration architecture learning design The Remote Control Approach - An Architecture for Adaptive Scripting across Collaborative Learning Environments Harrer, Andreas Wichmann, Astrid Malzahn, Nils collaboration scripts,integration architecture,learning design JUCS - Journal of Universal Computer Science Vol. 14 2008 01 148-173 Verlag der Technischen Universität Graz Universiti Malaysia Sarawak Graz, Austria