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The most widely used similarity metrics in collaborative filtering, namely the Pearson Correlation and the Adjusted Cosine Similarity, adjust each individual rating by the mean of the ratings entered by the specific user, when computing... more
The most widely used similarity metrics in collaborative filtering, namely the Pearson Correlation and the Adjusted Cosine Similarity, adjust each individual rating by the mean of the ratings entered by the specific user, when computing similarities, due to the fact that users follow different rating practices, in the sense that some are stricter when rating items, while others are more lenient. However, a user’s rating practices change over time, i.e. a user could start as lenient and subsequently become stricter or vice versa; hence by relying on a single mean value per user, we fail to follow such shifts in users’ rating practices, leading to decreased rating prediction accuracy. In this work, we present a novel algorithm for calculating dynamic user averages, i.e. time-in-point averages that follow shifts in users’ rating practices, and exploit them in both user-user and item-item collaborative filtering implementations. The proposed algorithm has been found to introduce significant gains in rating prediction accuracy, and outperforms other dynamic average computation approaches that are presented in the literature.
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This chapter presents an architecture for supporting the creation of adaptive virtual reality museums on the web. It argues whether the task of developing adaptive virtual reality museums is a complex one, presenting key challenges, and... more
This chapter presents an architecture for supporting the creation of adaptive virtual reality museums on the web. It argues whether the task of developing adaptive virtual reality museums is a complex one, presenting key challenges, and should thus be facilitated by means of a supporting architecture and relevant tools. The proposed architecture is flexible enough to cater for a variety of user needs, and modular promoting extensibility, maintainability and tailorability. Adoption of this architecture will greatly simplify the development of adaptive virtual reality museums, reducing the needed effort to exhibit digitisation and user profile specification; user profiles are further refined dynamically through the user data recorder and the user modelling engine, which provide input for the virtual environment generator.
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Research Interests: Information Systems, Computer Science, Artificial Intelligence, Security, Trust Management, and 9 moreComputer Security, Intrusion Detection System, Computer Networks and Communications, Information Systems Development And Management, Insider, Disaster Recovery Using Operations Research and Management Science, Blockchain, Insider threats, and Collaborative intrusion detection
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The concept of online teaching and learning is widely adopted by universities due to the pandemic of COVID-19, which forced them to shift from blending learning (including both direct and remote education) to exclusive online education.... more
The concept of online teaching and learning is widely adopted by universities due to the pandemic of COVID-19, which forced them to shift from blending learning (including both direct and remote education) to exclusive online education. Technology has provided a multitude of tools, which can prove very useful in the hands of people who want to serve such a great purpose as education. During the days of the pandemic, where people are isolated, virtual community and virtual learning technology brings people together to experience a sense of educational community in the virtual world. This chapter introduces the reader to the importance for social skill training of the learning communities during times that online learning is the sole type of education, exploring methodologies, tools, and practices that can be used to counterbalance the deficiencies introduced by distance learning methods regarding social skill development.
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Cyber-security training has evolved into an imperative need, aiming to provide cyber-security professionals with the knowledge and skills required to confront cyber-attacks that are increasing in number and sophistication. Training... more
Cyber-security training has evolved into an imperative need, aiming to provide cyber-security professionals with the knowledge and skills required to confront cyber-attacks that are increasing in number and sophistication. Training activities are typically associated with evaluation means, aimed to assess the extent to which the trainee has acquired the knowledge and skills whose development is targeted by the training programme, while cyber-security awareness and skill level evaluation means may be used to support additional security-related aspects of organizations. In this paper, we review trainee performance assessment metrics in cyber-security training, aiming to assist designers of cyber-security training activities to identify the most prominent trainee performance assessment means for their training programmes, while additional research directions involving cyber-security training evaluation metrics are also identified.
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Terrorism is a significant deterrent for tourism. It affects both visitors and local citizens and personnel of a country or area. On one hand, the potential visitor will probably avoid travelling to a high attack risk country, due to... more
Terrorism is a significant deterrent for tourism. It affects both visitors and local citizens and personnel of a country or area. On one hand, the potential visitor will probably avoid travelling to a high attack risk country, due to safety reasons, hence will miss the opportunity to visit it, and, on the other hand, the country’s tourism will decline. This work addresses the aforementioned problem by (1) showing that relatively safe visiting periods for high attack risk European countries can be predicted with high accuracy, using limited information, comprising of attack and fatality data from the past years, which are widely available, and (2) developing an algorithm that recommends relatively safe periods to potential travellers.
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Digital assistants—such as chatbots—facilitate the interaction between persons and machines and are increasingly used in web pages of enterprises and organizations. This paper presents a methodology for the creation of chatbots that offer... more
Digital assistants—such as chatbots—facilitate the interaction between persons and machines and are increasingly used in web pages of enterprises and organizations. This paper presents a methodology for the creation of chatbots that offer access to museum information. The paper introduces an information model that is offered through the chatbot, which subsequently maps the museum’s modeled information to structures of DialogFlow, Google’s chatbot engine. Means for automating the chatbot generation process are also presented. The evaluation of the methodology is illustrated through the application of a real case, wherein we developed a chatbot for the Archaeological Museum of Tripolis, Greece.
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The remedial teaching policy is a flagship education policy of the Greek Ministry of Education that aims to create a school of equal opportunities by providing additional support to students from disadvantaged social backgrounds. In this... more
The remedial teaching policy is a flagship education policy of the Greek Ministry of Education that aims to create a school of equal opportunities by providing additional support to students from disadvantaged social backgrounds. In this work we utilised a data set provided by the Ministry of Education, followed a black box approach and built on previous results in order to achieve the first ever evaluation, based on data, of the remedial teaching policy. Our findings indicate that remedial teaching is very effective in supporting very weak students, helping 70% of them achieve better academic performance and one out of three of them to sustain this enhanced academic performance in the future, long after they have stopped receiving remedial teaching. On the other hand, and contrary to what is widely believed, our results show that remedial teaching has the opposite impact to what it was designed for, as it is primarily the privileged students that receive the benefits. Consequently,...
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The dynamic development of Informatics introduces new educational and pedagogical challenges, including the instructional design of teaching and learning. How can we teach our students better in such a growing and demanding field?... more
The dynamic development of Informatics introduces new educational and pedagogical challenges, including the instructional design of teaching and learning. How can we teach our students better in such a growing and demanding field? Moreover, how can we motivate them and together have better learning results? This paper aims to give answers to these questions, through a student-centered framework for effectively encompassing alternative teaching methods within CS. The proposed framework (ATMF) summarizes the benefits of alternative teaching methods in contrast with known issues of traditional teaching. In addition, ATMF is built upon empirical evidence and concludes that alternative practices, if used under the right conditions, can provide increased motivation for learning and better learning outcomes.
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Abstract Intermittent faults are a very common problem in the software world, while difficult to be debugged. Most of the existing approaches though assume that suitable instrumentation has been provided in the program, typically in the... more
Abstract Intermittent faults are a very common problem in the software world, while difficult to be debugged. Most of the existing approaches though assume that suitable instrumentation has been provided in the program, typically in the form of assertions that dictate which program states are considered to be erroneous. In this paper we propose a method that can be used to detect probable sources of intermittent faults within a program. Our method proposes certain points in the code, whose data interdependencies combined with their execution interweaving indicate that they could be the cause of intermittent faults. It is the responsibility of the user to accept or reject these proposals. An advantage of this method is that it removes the need for having predefined assertion points in the code, being able to detect potential sources of intermittent faults in the whole bulk of the code, with no instrumentation requirements on the side of the programmer. The proposed approach exploits information from the dynamic behavior of the program. In comparison with parser-based approaches which analyze only the program structure, our approach is immutable to language term changes and in general is not depending on any user-provided assertions or configuration.
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ABSTRACT Technology has always dominated human society, and each stage of society’s development has corresponded to a certain technological limit. Thus, the leap to overcome the technological limit of each era has been marked by a... more
ABSTRACT Technology has always dominated human society, and each stage of society’s development has corresponded to a certain technological limit. Thus, the leap to overcome the technological limit of each era has been marked by a revolution. Examples of this are the development of the steam engine, in 1769, which marked the transition to the Industrial Age; and the first electronic computer, which was designed in 1937, constructed in 1944, and launched in 1946, marking the transition to the Cybernetic Era (Cornish, 2004). The evolution of information technology after 1970 turned information into a primary production factor alongside labor, nature, and capital. Consequently, at the end of the twentieth century, theory and practice in the field assimilated the concept of a new economy: the digital or Internet economy. Accounting has been present in human society ever since the division of labor. Over time, accounting, which is the technique and science of accounts, has adapted to the technological level and the limits of each era, especially through the evolution of the alphabet, numbers, and writing. When stone and clay were used for writing, they were found in the accounting memoirs, describing debts, claims, collections, and payments. Clay pads from temples such as Uruk, Nippur, Kiş, and Suruppak bear witness to this fact (Heilbroner, 1999; Lipin & Belov, 1962; Vlaemminck, 1956; Obert, 2011). The transition from using animal skin to using paper has led to significant progress in terms of accounting techniques. The invention of printing, in the first half of the sixteenth century, facilitated the popularization of the accounting science. Two centuries later, the Industrial Revolution found accounting ready to meet the information necessities imposed by the speeding up of the movement of production factors and by the needs of capital holders. Toward the end of the nineteenth century, accounting was revitalized in terms of its technique, from the perspective of new concepts and qualitative accumulations. To this effect, the United States imposed a rapid pace of modernization of accounting concepts and techniques in order to inform a wider range of accounting information users. The triggering of the cyber revolution, in the middle of the twentieth century, left its mark on developments in accounting at the beginning of the 1980s, when the average cost of electronic equipment became affordable to organizations that found themselves in the race for computerization, a characteristic of the first technological wave (Moschella 1995; O’Brien, 1999). The end of the twentieth century brought the need to assimilate the progress made by information and communication technology. In this new era marked by the digital economy, the literature explored the concept of digital accounting, which was specific to the digital economy. Over the last 4–5 years, the most popular information technique has been cloud computing, which is a collection of information and communication technologies that essentially represents the materialization of J. McCarthy’s idea of utility computing from the 1960s (Zhang et al., 2010; Parkhill, 1966). In this context, we consider that, through the assimilation of cloud computing technology into the organization, the concept of digital accounting can move to a superior level of macro-economic aggregation, which we call meta-digital accounting.
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Abstract: In this study we present a technique for the parallel optimisation of join queries, that uses the offered coarse-grain parallelism of the underlying architecture in order to reduce the CPU-bound optimisation overhead. The... more
Abstract: In this study we present a technique for the parallel optimisation of join queries, that uses the offered coarse-grain parallelism of the underlying architecture in order to reduce the CPU-bound optimisation overhead. The optimisation technique performs an almost ...
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We introduce a novel knowledge-based recommendation algorithm for leisure time information to be used in social networks, which enhances the state-of-the-art in this algorithm category by taking into account (a) qualitative aspects of the... more
We introduce a novel knowledge-based recommendation algorithm for leisure time information to be used in social networks, which enhances the state-of-the-art in this algorithm category by taking into account (a) qualitative aspects of the recommended places (restaurants, museums, tourist attractions etc.), such as price, service and atmosphere, (b) influencing factors between social network users, (c) the semantic and geographical distance between locations and (d) the semantic categorization of the places to be recommended. The combination of these features leads to more accurate and better user-targeted leisure time recommendations.
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The GPA is a universally recognised and utilised metric of academic performance that is considered to also measure a student’s potential for academic performance in the future. In this short communication we examine to what extent the GPA... more
The GPA is a universally recognised and utilised metric of academic performance that is considered to also measure a student’s potential for academic performance in the future. In this short communication we examine to what extent the GPA of the first grade of high school predicts performance in the later grades of high school, either generally (as classified in excellent student, strong student, weak student or very weak student) or more accurately (as indicated by the exact GPA in the next grade). We also put to the test the widely held notion that it might be best if core courses such as language and mathematics contributed more to the calculation of the GPA compared to secondary courses such as physical education or music. Our findings confirm the predictive properties of the GPA but strongly rebut the notion that a weighted GPA might achieve a better reflection of students’ potential. The study is based on the academic records of every student in Greece that progressed from fir...
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Collaborative filtering has proved to be one of the most popular and successful rating prediction techniques over the last few years. In collaborative filtering, each rating prediction, concerning a product or a service, is based on the... more
Collaborative filtering has proved to be one of the most popular and successful rating prediction techniques over the last few years. In collaborative filtering, each rating prediction, concerning a product or a service, is based on the rating values that users that are considered “close” to the user for whom the prediction is being generated have given to the same product or service. In general, “close” users for some user u correspond to users that have rated items similarly to u and these users are termed as “near neighbors”. As a result, the more reliable these near neighbors are, the more successful predictions the collaborative filtering system will compute and ultimately, the more successful recommendations the recommender system will generate. However, when the dataset’s density is relatively low, it is hard to find reliable near neighbors and hence many predictions fail, resulting in low recommender system reliability. In this work, we present a method that enhances rating ...
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Exploitation and use of disruptive technologies, such as the Internet of Things, recommender systems, and artificial intelligence, with an ambidextrous balance, are a challenge, nowadays. Users of the technologies, and stakeholders, could... more
Exploitation and use of disruptive technologies, such as the Internet of Things, recommender systems, and artificial intelligence, with an ambidextrous balance, are a challenge, nowadays. Users of the technologies, and stakeholders, could be part of a new organisational model that affects business procedures and processes. Additionally, the use of inclusive participatory organisational models is essential for the effective adoption of these technologies. Such models aim to transform organisational structures, as well. Public organisations, such as the parliament, could utilise information systems’ personalisation techniques. As there are a lot of efforts to define the framework, the methodology, the techniques, the platforms, and the suitable models for digital technologies adoption in public organisations, this paper aims to provide a literature review for disruptive technology inclusive use in parliaments. The review emphasises the assessment of the applicability of the technologi...
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The tourism sector increasingly relies on technology to acquire new clients in a world overflowing with information. So, the main question that needs to be answered is:What digital marketing strategy should be adopted to attract customers... more
The tourism sector increasingly relies on technology to acquire new clients in a world overflowing with information. So, the main question that needs to be answered is:What digital marketing strategy should be adopted to attract customers and built digital brand name by incorporating websites and social media big data? The authors of this research utilize web analytics and big data to build an innovative methodology in an effort to address this issue. After the data collection, statistical analysis was implemented, followed by a fuzzy cognitive map and an agent-based simulation model in order to illustrate the usage of social media and user experience in multichannel marketing. The findings suggest that, in contrast to the websites of other industries, such as logistics, where customers want to finish their inquiries as quickly as possible and leave the webpage, it is advantageous for tourism websites to keep customers’ attention moreon their website in order to increasevisibility. ...
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In a world overwhelmed with unstructured information, logistics companies increasingly depend on their websites to acquire new customers and maintain existing ones. Following this rationale, a series of technical elements may set the... more
In a world overwhelmed with unstructured information, logistics companies increasingly depend on their websites to acquire new customers and maintain existing ones. Following this rationale, a series of technical elements may set the ground for differentiating one logistics website from another. Nevertheless, a suitable digital marketing strategy should be adopted in order to build competitive advantage. In this paper, the authors attempt to respond by implementing an innovative methodology building on web analytics and big data. The first phase of the research collects data for 180 days from 7 world-leading logistics companies. The second phase presents the statistical analysis of the gathered data, including regression, correlations, and descriptive statistics. Subsequently, Fuzzy Cognitive Mapping (FCM) was employed to illustrate the cause-and-effect links among the metrics in question. Finally, a predictive simulation model is developed to show the intercorrelation among the met...
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This article provides a visualization of a literature review in students’ performance prediction using educational data mining (EDM) techniques for the period 2015-2019. The results of the review are presented concisely and simply with... more
This article provides a visualization of a literature review in students’ performance prediction using educational data mining (EDM) techniques for the period 2015-2019. The results of the review are presented concisely and simply with the use of diagrams. Various aspects of the literature are examined, such as the algorithms adopted, the type of results drawn, the educational setting of the application and the actual exploitation of the outcomes. Findings indicate that tertiary education dominates the EDM field; in contrast, the focus given to secondary and primary education is minimal.
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Social media usage is affecting peoples’ views through opinion sharing, a fact that has started to attract cultural institutions, as it is possible that this procedure can possibly be a part of a museum experience. As the main goal of a... more
Social media usage is affecting peoples’ views through opinion sharing, a fact that has started to attract cultural institutions, as it is possible that this procedure can possibly be a part of a museum experience. As the main goal of a cultural institution is the maximization of senses stimulation, the device that is offered to the visitors’ hands everyday and every moment, becomes an important tool for the art spaces. In this notion we perform research on issues that can be of great importance for the museum’s online presence and attraction. We focus on establishing the personality of influencers related to culture, as well as the characteristics of qualitative discussions on the social media. Crosscult Project is an EU funded project, that aims to spur a change in the way European citizens appraise History, and sets that basis of our research as the experiments are conducted within its scope of. Through the experimental procedure, we collect information in order to define the cha...
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HCI-VR lab in Short. The Human-Computer Interaction and Virtual Reality Lab, at the Department of Informatics and Telecommunications of the University of Peloponnese, aims to conduct high quality research in areas related to the analysis,... more
HCI-VR lab in Short. The Human-Computer Interaction and Virtual Reality Lab, at the Department of Informatics and Telecommunications of the University of Peloponnese, aims to conduct high quality research in areas related to the analysis, design, development, and evaluation of HCI and VR systems and applications, and in parallel to support the teaching requirements of the department in the respective field. Over the last years the HCI-VR lab particularly focuses on Cultural Heritage and develops technologies primarily for spaces of cultural heritage that cover the diverse needs of heterogeneous audiences providing holistic visitor experience. The HCI-VR lab is actively participating in National and European projects on Cultural Heritage, such as FP7 Experimedia (https://hci-vr.dit.uop.gr/experimedia), H2020 CrossCult (www.crosscult.eu) and multiple projects from the National Strategic Reference Framework.
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This work addresses the challenges of creating usable and personalized conversational interfaces for broad, yet applicable, domains that require user engagement and learning, such as museum chatbots. Whether the chatbots are standalone or... more
This work addresses the challenges of creating usable and personalized conversational interfaces for broad, yet applicable, domains that require user engagement and learning, such as museum chatbots. Whether the chatbots are standalone or coupled with virtual agents or real-life robots, the functional requirements for interaction that targets specific learning aspects would be expected to be more or less similar. This work reports on experimental semantics-driven conversational interface design for chatbots in museum settings, targeting visitors to converse about exhibits and learn information about their style, the artists, the era, and other aspects related to them. Depending on the semantics (presentation, learning, exploration), chatbot scenarios were designed and evaluated by participants in a formative evaluation. The evaluation show that user requirement perception manifests in expectations on the semantic level, instead of just the technical level. The results between the sc...
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This article presents the work on social media analysis-driven policy-making platforms that are powered by classic social media analysis technologies, such as policy modelling, linguistic analysis, opinion mining, sentiment analysis and... more
This article presents the work on social media analysis-driven policy-making platforms that are powered by classic social media analysis technologies, such as policy modelling, linguistic analysis, opinion mining, sentiment analysis and information visualization. The approach examines the user design perspective towards user experience in policymaking for all the innovative modules used. The technology behind such complex task is presented while the resulting platform is appraised on the potential for real world application. The findings drive the development and the requirements for the summative usability assessment tests. We also report on the level the practitioners adopted the policy formulation tools.
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We present Tripmentor, a novel project, that is related to tourism in the region of Attica. The project has as main scope to provide rich media content to tourists through a web and mobile environment in two languages trying to guide them... more
We present Tripmentor, a novel project, that is related to tourism in the region of Attica. The project has as main scope to provide rich media content to tourists through a web and mobile environment in two languages trying to guide them through alternative routes that include places of interest as well as organizations with offers to tourists. The project interconnects people with places and events in an automated manner trying to personalize on each tourist’s personality. The challenges of the project are mainly technological as through the processes of the project a) automated information about venues must be collected, b) information about events related to venues must be fetched and finally c) data related to system users and mainly their profile should be discovered and created in order to offer a unique experience to each of them. We present the scope of the project as well as the challenges of its implementation.
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The paper presents recent work on the design and development of AI chatbots for museums using Knowledge Graphs (KGs). The utilization of KGs as a key technology for implementing chatbots raises not only issues related to the... more
The paper presents recent work on the design and development of AI chatbots for museums using Knowledge Graphs (KGs). The utilization of KGs as a key technology for implementing chatbots raises not only issues related to the representation and structuring of exhibits’ knowledge in suitable formalism and models, but also issues related to the translation of natural language dialogues to and from the selected technology for the formal representation and structuring of information and knowledge. Moreover, such a translation must be as transparent as possible to visitors, towards a realistic human-like question-answering process. The paper reviews and evaluates a number of recent approaches for the use of KGs in developing AI chatbots, as well as key tools that provide solutions for natural language translation and the querying of Knowledge Bases and Linked Open Data sources. This evaluation aims to provide answers to issues that are identified within the proposed MuBot approach for des...
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Creating stories for exhibitions is a fascinating and in parallel laborious task. As every exhibition is designed to tell a story, museum curators are responsible for identifying, for each exhibit, its aspects that fit to the message of... more
Creating stories for exhibitions is a fascinating and in parallel laborious task. As every exhibition is designed to tell a story, museum curators are responsible for identifying, for each exhibit, its aspects that fit to the message of the story and position the exhibit at the right place in the story thread. In this context, we analyze how the technological advances in the fields of sensors and Internet of Things can be utilized in order to construct a “smart space,” which consists of self-organizing exhibits that cooperate with each other and provide visitors with comprehensible, rich, diverse, personalized, and highly stimulating experiences. We present the system named “exhiSTORY” that intends to provide the appropriate infrastructure to be used in museums and places where exhibitions are held in order to support smart exhibits. The architecture of the system and its application potential is presented and discussed.
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Metacognitive training reflects knowledge, consideration and control over decision-making and task performance evident in any social and learning context. Interest in understanding the best account of effective (win-win) negotiation... more
Metacognitive training reflects knowledge, consideration and control over decision-making and task performance evident in any social and learning context. Interest in understanding the best account of effective (win-win) negotiation emerges in different social and cultural interactions worldwide. The research presented in this paper explores an extended study of metacognitive training system during negotiation using an embodied conversational agent. It elaborates on the findings from the usability evaluation employing 40 adult learners pre- and postinteraction with the system, reporting on the usability and metacognitive, individual- and community-level related attributes. Empirical evidence indicates (a) higher levels of self-efficacy, individual readiness to change and civic action after user-system experience, (b) significant and positive direct associations between self-efficacy, self-regulation, interpersonal and problem-solving skills, individual readiness to change, mastery g...
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Advancements in cultural informatics have significantly influenced the way we perceive, analyze, communicate and understand culture. New data sources, such as social media, digitized cultural content, and Internet of Things (IoT) devices,... more
Advancements in cultural informatics have significantly influenced the way we perceive, analyze, communicate and understand culture. New data sources, such as social media, digitized cultural content, and Internet of Things (IoT) devices, have allowed us to enrich and customize the cultural experience, but at the same time have created an avalanche of new data that needs to be stored and appropriately managed in order to be of value. Although data management plays a central role in driving forward the cultural heritage domain, the solutions applied so far are fragmented, physically distributed, require specialized IT knowledge to deploy, and entail significant IT experience to operate even for trivial tasks. In this work, we present Hydria, an online data lake that allows users without any IT background to harvest, store, organize, analyze and share heterogeneous, multi-faceted cultural heritage data. Hydria provides a zero-administration, zero-cost, integrated framework that enable...
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This paper presents SemMR, a semantic framework for modelling interactions between human and non-human entities and managing reusable and optimized cultural experiences, towards a shared cultural experience ecosystem that might seamlessly... more
This paper presents SemMR, a semantic framework for modelling interactions between human and non-human entities and managing reusable and optimized cultural experiences, towards a shared cultural experience ecosystem that might seamlessly accommodate mixed reality experiences. The SemMR framework synthesizes and integrates interaction data into semantically rich reusable structures and facilitates the interaction between different types of entities in a symbiotic way, within a large, virtual, and fully experiential open world, promoting experience sharing at the user level, as well as data/application interoperability and low-effort implementation at the software engineering level. The proposed semantic framework introduces methods for low-effort implementation and the deployment of open and reusable cultural content, applications, and tools, around the concept of cultural experience as a semantic trajectory or simply, experience as a trajectory (eX-trajectory). The methods facilita...
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The contemporary internet has developed into a complex ecosystem involving humans, services, applications, machines and applications that interact exchanging information, ranging from e-mail messages and social media content to... more
The contemporary internet has developed into a complex ecosystem involving humans, services, applications, machines and applications that interact exchanging information, ranging from e-mail messages and social media content to crowdsourcing data and videoconferencing. In this context, a number of security threats such as viruses and malware exist, while additionally the users’ privacy is jeopardized by threats such as personal data leakage, usage pattern monitoring, and so forth. The IoT trend renders the Internet ecosystem even more complex, by adding a rich set of services, applications and machines, many of them backed by new user roles; these elements are weaved into everyday life and industry alike. This increases both the number of opportunities available to threat agents for exploitation and the volume and value of the underlying infrastructure and data, increasing thus the user risk level. In this paper, we explore how the Blockchain technology can be used to leverage secur...
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Recommender systems are based on information about users’ past behavior to formulate recommendations about their future actions. However, as time goes by the interests and likings of people may change: people listen to different singers... more
Recommender systems are based on information about users’ past behavior to formulate recommendations about their future actions. However, as time goes by the interests and likings of people may change: people listen to different singers or even different types of music, watch different types of movies, read different types of books and so on. Due to this type of changes, an amount of inconsistency is introduced in the database since a portion of it does not reflect the current preferences of the user, which is its intended purpose.
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... Gartenfeld. B2C Success at Wishlist.com / Delyth Samuel and Danny Samson. BSC-Based Framework for E-Business Strategy / Fen Wang and Guisseppi Forgionne. Branding on the Internet / Mary Lou Roberts and Eric Schwaab. ...
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There is a wide range of meta-data standards for the documentation of museum related information, such as CIDOC-CRM; these standards focus on the description of distinct exhibits. In contrast, there is a lack of standards for the... more
There is a wide range of meta-data standards for the documentation of museum related information, such as CIDOC-CRM; these standards focus on the description of distinct exhibits. In contrast, there is a lack of standards for the digitization and documentation of the routes followed and information provided by museum guides. In this work we propose the notion of the narrative, which can be used to model a guided museum visit. We provide a formalization for the narrative so that it can be digitally encoded, and thus preserved, shared, re-used, further developed and exploited, and also propose an intuitive visualization approach.
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This paper investigates the effect that smart routing and recommendations can have on improving the Quality of Experience of museum visitors. The novelty of our approach consists of taking into account not only user interests but also... more
This paper investigates the effect that smart routing and recommendations can have on improving the Quality of Experience of museum visitors. The novelty of our approach consists of taking into account not only user interests but also their visiting styles, as well as modeling the museum not as a sterile space but as a location where crowds meet and interact, impacting each visitor’s Quality of Experience. The investigation is done by an empirical study on data gathered by a custom-made simulator tailored for the museum user routing problem. Results are promisingand future potential and directions are discussed.
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In this paper we examine the suitability of the Google Cardboard as a means for the delivery of personalized cultural experiences. Specifically, we develop the content and create the application required in order to provide highly... more
In this paper we examine the suitability of the Google Cardboard as a means for the delivery of personalized cultural experiences. Specifically, we develop the content and create the application required in order to provide highly personalized visits to the Archaeological Museum in Tripolis, Greece. We also examine the usability issues related to the use of Google Cardboards. Early results are promising, and based on them we also outline the next steps ahead.
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WS-BPEL scenario execution adaptation has been proposed by researchers as a response to the need of users to tailor the WS-BPEL scenario execution to their individual preferences; these preferences are typically expressed through Quality... more
WS-BPEL scenario execution adaptation has been proposed by researchers as a response to the need of users to tailor the WS-BPEL scenario execution to their individual preferences; these preferences are typically expressed through Quality of Service (QoS) policies, which the adaptation mechanism considers in order to select the services that will ultimately be invoked to realize the desired business process. In this paper, we study the potential to parallelize the execution of the WS-BPEL scenario in order to minimize its response time and/or achieving higher scores in the other qualitative dimensions, such as cost, reliability, etc., at the same time. We also describe, develop and validate a parallelization algorithm for realizing the proposed enhancements.
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WS-BPEL scenario execution adaptation has been proposed by numerous researchers as a response to the need of users to tailor the WS-BPEL scenario execution to their individual preferences, these preferences are typically expressed through... more
WS-BPEL scenario execution adaptation has been proposed by numerous researchers as a response to the need of users to tailor the WS-BPEL scenario execution to their individual preferences, these preferences are typically expressed through Quality of Service (QoS) policies, which the adaptation mechanism considers in order to select the services that will ultimately be invoked to realize the desired business process. In this paper, we consider a number of issues related to WS-BPEL scenario adaptation, aiming to enhance adaptation quality and improve the QoS offered to end users. More specifically, with the goal of broadening the service selection pool we (a) discuss the identification of potential services that can be used to realize a functionality used in the WS-BPEL scenario and (b) elaborate on transactional semantics that invocations to multiple services offered by the same provider may bear. We also describe and validate an architecture for realizing the proposed enhancements.
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Abstract: In the past years, a number of implementations of temporal DBMSs has been reported. Most of these implementations share a common feature, which is that they have been built as an extension to a snapshot DBMS. In this paper, we... more
Abstract: In the past years, a number of implementations of temporal DBMSs has been reported. Most of these implementations share a common feature, which is that they have been built as an extension to a snapshot DBMS. In this paper, we present three alternative design approaches that can be used for extending a snapshot DBMS to support temporal data, and evaluate the suitability of each approach, with respect to a number of design objectives. 1.
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Manolis Kalikakis, e-Government Laboratory, University of Athens, email mkalikakis@gmail.com Dimitris Gouscos, Department of Communication and Media Studies, University of Athens, email gouscos@media.uoa.gr Kostas Vassilakis, Department... more
Manolis Kalikakis, e-Government Laboratory, University of Athens, email mkalikakis@gmail.com Dimitris Gouscos, Department of Communication and Media Studies, University of Athens, email gouscos@media.uoa.gr Kostas Vassilakis, Department of Computer Science and Technology, University of Peloponnese, email costas@uop.gr Panagiotis Georgiadis, e-Government Laboratory, University of Athens, email P.Georgiadis@di.uoa.gr
Mobile commerce is gaining significant importance in the recent years as an alternative option of e-commerce for the moving user. The mobile applications through which m-commerce takes place operate in highly dynamic environments with... more
Mobile commerce is gaining significant importance in the recent years as an alternative option of e-commerce for the moving user. The mobile applications through which m-commerce takes place operate in highly dynamic environments with diverse characteristics and under varying conditions. The characteristics and conditions of these environments -- called context -- should be exploited in order to provide adaptive services, services that offer a suitable user experience and deliver innovative and enhanced capabilities that will facilitate user interaction, attract new customers and maintain existing ones. The goal of adaptivity is realized through the adaptation of user interface, functionality and content of applications using the context information. Therefore, context-awareness constitutes an essential aspect -- almost a requirement -- of mobile services. In order to realize context-aware services, there is a necessity to capture the context information from its sources, process and distribute it to the software components that will use it. In this paper, we propose a software architecture for context information management suitable for m-commerce applications. We describe the functionality and characteristics of its components, as well as the interaction among these different components.
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Abstract: On their route to e-governance, public administrations have developed e-services. Each e-service encompasses a significant amount of knowledge in the form of examples, help texts, legislation excerpts, validation checks etc.... more
Abstract: On their route to e-governance, public administrations have developed e-services. Each e-service encompasses a significant amount of knowledge in the form of examples, help texts, legislation excerpts, validation checks etc. This knowledge has been offered by domain experts in the phases of service analysis, design and implementation, being however bundled within the software, it cannot be readily retrieved and used in other organizational processes, including the development of new services. In this paper, we ...
Abstract. Public transaction services (such as e-forms), although perceived the future of e-government have not yet realised their full potential. E-forms have a significant role in e-government, as they are the basis for realising most... more
Abstract. Public transaction services (such as e-forms), although perceived the future of e-government have not yet realised their full potential. E-forms have a significant role in e-government, as they are the basis for realising most of the twenty public services that all European Union member states have to provide to their citizens and businesses. The aim of this paper is to present a knowledgebased platform to assist public sector employees to generate online transaction services by simplifying their development, maintenance and ...
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Novel and intelligent visualization methods are being developed in order to accommodate user searching and browsing tasks, including new and advanced functionalities. Besides, research in the field of user modeling is progressing in order... more
Novel and intelligent visualization methods are being developed in order to accommodate user searching and browsing tasks, including new and advanced functionalities. Besides, research in the field of user modeling is progressing in order to personalize these visualization systems, according to its users’ individual profiles. However, employing a single visualization system, may not suit best any information seeking activity. In this paper we present a visualization environment, which is based on a visualization library, i.e. is a set of visualization methods, from which the most appropriate one is selected for presenting information to the user. This selection is performed combining information extracted from the context of the user, the system configuration and the data collection. A set of rules inputs such information and assigns a score to all candidate visualization methods. The presented environment additionally monitors user behavior and preferences to adapt the visualizatio...
Research Interests: Computer Science, Visualization, Information Visualization, Information Extraction, Knowledge Based System, and 13 moreData Visualization, Creative Visualization, Information seeking, Visual System, Data Collection, Selection Criteria, Intelligent User Interfaces, User Behavior, Information Seeking, Information Presentation, System center configuration manager, user model, and Information Search and Retrieval
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Personal ontologies have been proposed as a means to support the semantic management of user information. Assuming that a personal ontology system is in use, new tools have to be developed at user interface level to exploit the enhanced... more
Personal ontologies have been proposed as a means to support the semantic management of user information. Assuming that a personal ontology system is in use, new tools have to be developed at user interface level to exploit the enhanced capabilities offered by the system. In this work, we present an ontology-based file manager that allows semantic searching on the user's personal information space. The file manager exploits the ontology relations to present files associated with specific concepts, proposes new related concepts to users, and helps them explore the information space and locate the required file.
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ABSTRACT Incorporating digital tools in the business and scientific research workflows is at the moment an on-going process, challenging and demanding as every domain has its own needs in terms of data models and information retrieval... more
ABSTRACT Incorporating digital tools in the business and scientific research workflows is at the moment an on-going process, challenging and demanding as every domain has its own needs in terms of data models and information retrieval methods. The information in some domains involves entity evolution, a characteristic that introduces additional tasks, such as finding all evolution stages of an entity, and poses additional requirements for the information retrieval process. In this paper, we present a user study aiming to investigate how the different aspects of ontology modelling affect the performance and effectiveness of users regarding information retrieval tasks that are carried out using visualization methods. The results of the user study are analyzed and guidelines for ontology design are offered.
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ABSTRACT In this paper, we present a framework which provides runtime adaptation for BPEL scenarios. The adaptation is based on (a) quality of service parameters of available web services (b) quality of service policies specified by users... more
ABSTRACT In this paper, we present a framework which provides runtime adaptation for BPEL scenarios. The adaptation is based on (a) quality of service parameters of available web services (b) quality of service policies specified by users (c) collaborative filtering techniques, allowing clients to further refine the adaptation process by considering service selections made by other clients, (d) monitoring, in order to follow the variations of QoS attribute values and (e) on users’ opinions services they have used.
Digitization efforts and web presentations are currently on-going in many museums, archives, libraries and culture heritage institutions in general, exploiting the advent of WWW and digitization technologies. The main benefits from these... more
Digitization efforts and web presentations are currently on-going in many museums, archives, libraries and culture heritage institutions in general, exploiting the advent of WWW and digitization technologies. The main benefits from these efforts are exhibit cataloguing, their effective management, preservation and showcasing, and their presentation to the public through the WWW. However, many museums, especially the smaller ones, cannot afford a commercial product and resort to using simple static web pages for their web presence and exhibit presentation. Content Management Systems (CMS), especially open-source ones which come with practically zero-cost, are more and more frequently adopted by museums to create and maintain their website, since they simplify the creation and editing of the web pages and may be used by non-computer experts. In this work we present a module for the Drupal CMS, which provides functionality for (a) Database schema extension to accommodate museum exhibit...
Hierarchical data structures are one of the most commonly used data structures in computer science, and therefore numerous methods and techniques have been proposed for their visualization. In this paper, we present our findings from a... more
Hierarchical data structures are one of the most commonly used data structures in computer science, and therefore numerous methods and techniques have been proposed for their visualization. In this paper, we present our findings from a user study, in which a number of folder visualization environments were evaluated to assess (a) how efficiently a number of tasks can be performed within the different environments (b) the extent to which using a particular visualization may help the user acquire an accurate cognitive image of the hierarchy structure and its contents and (c) the overall user experience from using a particular visualization environment. The visualization environments considered are representative of major visualization paradigms (zoomable user interfaces, context+focus and space-filling), while both 2D and 3D environments have been included.
ABSTRACT Recommender systems aim to propose items that are expected to be of interest to the users. As one of the most successful approaches to building recommender systems, collaborative filtering exploits the known preferences of a... more
ABSTRACT Recommender systems aim to propose items that are expected to be of interest to the users. As one of the most successful approaches to building recommender systems, collaborative filtering exploits the known preferences of a group of users to formulate recommendations or predictions of the unknown preferences for other users. In many cases, collaborative filtering algorithms handle complex items, which are described using hierarchical tree structures containing rich semantic information. In order to make accurate recommendations on such items, the related algorithms must examine all aspects of the available semantic information. Thus, when collaborative filtering techniques are employed to adapt the execution of business processes, they must take into account the services’ Quality of Service parameters, so as to generate recommendations tailored to the individual user needs. In this paper, we present a collaborative filtering-based algorithm which takes into account the web services’ QoS parameters in order to tailor the execution of business processes to the preferences of users. An offline clustering technique is also introduced for supporting the efficient and scalable execution of proposed algorithm under the presence of large repositories of sparse data.
Distributed software systems need to evolve according to the ever-changing requirements on which they were built. Software systems' tailorability can be achieved in terms of component software. Atoms and... more
Distributed software systems need to evolve according to the ever-changing requirements on which they were built. Software systems' tailorability can be achieved in terms of component software. Atoms and molecules the basic constructs of the ATOMA framework are the building blocks for distributed tailorable component-based software systems. These constructs can be considered as independent agents, that communicate in terms of
Research Interests: Information Systems, Computer Architecture, Software Engineering, Informatics, Polymorphism, and 10 moreSystems Analysis, Software Architecture, Component-Based Software Engineering (CBSE), Production Systems, Computer Languages, Components, Profiling, Software Systems, Rule Based, and Agent Communication
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Novel and intelligent visualization methods are being developed in order to accommodate user searching and browsing tasks, including new and advanced functionalities. Besides, research in the field of user modeling is progressing in order... more
Novel and intelligent visualization methods are being developed in order to accommodate user searching and browsing tasks, including new and advanced functionalities. Besides, research in the field of user modeling is progressing in order to personalize these visualization systems, according to its users' individual profiles. However, employing a single visualization system, may not suit best any information seeking activity. In this paper we present a visualization environment, which is based on a visualization ...
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ABSTRACT This paper presents an innovative approach based on social-network gaming, which will extract players’ cognitive styles for personalization purposes. Cognitive styles describe the way individuals think, perceive and remember... more
ABSTRACT This paper presents an innovative approach based on social-network gaming, which will extract players’ cognitive styles for personalization purposes. Cognitive styles describe the way individuals think, perceive and remember information and can be exploited to personalize user interaction. Questionnaires are usually employed to identify cognitive styles, a tedious process for most users. Our approach relies on a Facebook game for discovering potential visitors’ cognitive styles with an ultimate goal of enhancing the overall visitors' experience in the museum. By hosting such a game on the museum’s webpage and on Facebook, the museum aims to attract new visitors, as well as to support the user profiling process.
ABSTRACT In this paper, we present the vision of an open source learning analytics platform, able to harvest data from different sources, including e-learning platforms and environments, registrar's information systems, alumni... more
ABSTRACT In this paper, we present the vision of an open source learning analytics platform, able to harvest data from different sources, including e-learning platforms and environments, registrar's information systems, alumni systems, etc., so as to provide all stakeholders with the necessary functionality to make decisions on the learning process. The platform's architecture is modular, allowing the introduction of new functionality or connection to new systems to collect needed data. All data can be analyzed and presented though interactive visualizations to find correlations between metrics, to make predictions for students or student groups, to identify best practices for instructors and let them explore 'what-if' scenarios, to offer students personalized recommendations and personalized detailed feedback, etc. Our objective is to inform and empower all stakeholders to improve the learning experience.
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ABSTRACT WS-BPEL has been adopted as the predominant method for composing individual web services into higher-level business processes. The designers of WS-BPEL scenarios define at development time the specific web services that will be... more
ABSTRACT WS-BPEL has been adopted as the predominant method for composing individual web services into higher-level business processes. The designers of WS-BPEL scenarios define at development time the specific web services that will be invoked in the context of the business process they model; in the context however of the current web, where each functionality is offered by multiple service providers, under different quality of service parameters, using a fixed BPEL scenario has been recognized to be inadequate for servicing the diverse needs of business processes clients. To this end, WS-BPEL scenario execution adaptation has been proposed, mainly allowing clients to specify quality of service policies, which drive the dynamic selection of the services that will be invoked. In this paper, we present a framework extending the quality of service-based adaptation mechanisms with collaborative filtering techniques, allowing clients to further refine the adaptation process by considering service selections made by other clients, in the context of the same business processes.
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ABSTRACT In contemporary internet architectures, including server farms and blog aggregators, web log data may be scattered among multiple cooperating peers. In order to perform content personalisation through provision of recommendations... more
ABSTRACT In contemporary internet architectures, including server farms and blog aggregators, web log data may be scattered among multiple cooperating peers. In order to perform content personalisation through provision of recommendations on such architectures, it is necessary to employ a recommendation algorithm; however, the majority of such algorithms are centralised, necessitating excessive data transfers and exhibiting performance issues when the number of users or the volume of data increase. In this paper, we propose an approach where the clickstream information is distributed to a number of peers, which cooperate for discovering frequent patterns and for generating recommendations, introducing: a) architectures that allow the distribution of both the content and the clickstream database to the participating peers; b) algorithms that allow collaborative decisions on the recommendations to the users, in the presence of scattered log information. The proposed approach may be employed in various domains, including digital libraries, social data, server farms and content distribution networks.
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... TOQL doesn't have any active capabilities, so this part of the T ODMG model cannot be supported. Page 10. Chapter 2 Temporal Extensions to ODMG ... AOST is the set of ODMG atomic object system types; it is de ned as the following... more
... TOQL doesn't have any active capabilities, so this part of the T ODMG model cannot be supported. Page 10. Chapter 2 Temporal Extensions to ODMG ... AOST is the set of ODMG atomic object system types; it is de ned as the following set fObject, Collection, Set, Bag, List, Arrayg; ...
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... Toward a world with quantum computers. Dave Bacon, Debbie Leung. ... In a world where computer gates are made of such microscopic entities, the physical laws of quantum theory dominate, and as such, the rules governing information... more
... Toward a world with quantum computers. Dave Bacon, Debbie Leung. ... In a world where computer gates are made of such microscopic entities, the physical laws of quantum theory dominate, and as such, the rules governing information processing change drastically. ...
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We propose a model for the estimation of query execution time in an environment supporting bushy and pipelined parallelism. We consider a parallel architecture of processors having private main memories, accessing a shared secondary... more
We propose a model for the estimation of query execution time in an environment supporting bushy and pipelined parallelism. We consider a parallel architecture of processors having private main memories, accessing a shared secondary storage and ...
Ontologies have been proven invaluable tools in areas like the semantic web and personal information management. They model concepts and relationships in a high level of abstraction, providing rich semantics for humans to work with and... more
Ontologies have been proven invaluable tools in areas like the semantic web and personal information management. They model concepts and relationships in a high level of abstraction, providing rich semantics for humans to work with and the required formalism for computers to ...
... II. Germanakos, Panagiotis. ... Anna Sialarou University of Cyprus, Cyprus Barry Smyth University College Dublin, Ireland Charis Rizopoulos National & Kapodistrian University of Athens, Greece Christoforos Panayiotou University of... more
... II. Germanakos, Panagiotis. ... Anna Sialarou University of Cyprus, Cyprus Barry Smyth University College Dublin, Ireland Charis Rizopoulos National & Kapodistrian University of Athens, Greece Christoforos Panayiotou University of Cyprus, Cyprus Dimitris Charitos National & ...
Abstract: This paper describes a technique for interceding between users and the information that they browse. This facility, that we term 'dynamic annotation', affords a means of editing Web page content... more
Abstract: This paper describes a technique for interceding between users and the information that they browse. This facility, that we term 'dynamic annotation', affords a means of editing Web page content 'on-the-fly'between the source Web server and the requesting client. Thereby, we have a generic way of modifying the content displayed to local users by addition, removal or reorganising any information sourced from the World-Wide Web, whether this derives from local or remote pages. For some time, we have been exploring ...
Electronic commerce, nowadays, is trying to extend its target audience and elevate the quality of services offered to end-users. Two important directions towards meeting these goals are the embracement of mobile users, whose number grows... more
Electronic commerce, nowadays, is trying to extend its target audience and elevate the quality of services offered to end-users. Two important directions towards meeting these goals are the embracement of mobile users, whose number grows following the advent of communication technologies, and the inclusion of context-aware features in the delivered services to improve the efficiency of the dialogues between users and systems. The context taken into account may involve characteristics regarding the human user, the ...
Abstract. Personal ontologies have been proposed as a means to support the semantic management of user information. Assuming that a personal ontology system is in use, new tools have to be developed at user interface level to exploit the... more
Abstract. Personal ontologies have been proposed as a means to support the semantic management of user information. Assuming that a personal ontology system is in use, new tools have to be developed at user interface level to exploit the enhanced capabilities offered by the system. In this work, we present an ontology-based file manager that allows semantic searching on the user's personal information space. The file manager exploits the ontology relations to present files associated with specific concepts, proposes new related ...
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The construction of multilingual web sites is probably the best answer to addressing the problem of the diverse cultural background of the Internet community. However, developing multiple instances of the same site in different languages... more
The construction of multilingual web sites is probably the best answer to addressing the problem of the diverse cultural background of the Internet community. However, developing multiple instances of the same site in different languages induces increased overhead for both the implementation and the maintenance phase. The paper reviews current techniques and describes an alternative to constructing multilingual web sites, which eases the development and maintenance phases, without possessing any of the drawbacks of ...
The ever changing environment information systems model, and in particular e-government ones, intensifies the need for systems that are able to easily, efficiently and transparently adapt to changing environments. Accommodating... more
The ever changing environment information systems model, and in particular e-government ones, intensifies the need for systems that are able to easily, efficiently and transparently adapt to changing environments. Accommodating unanticipated changes implies that systems must be able to adapt to changes occurring in and evolve in step with their changing environment. Adaptation is concerned with monitoring, analysing and understanding the patterns of the user's interaction with the system. Similarly, an ...
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This paper describes a technique for interceding between users and the information that they browse. This facility, that we term'dynamic annotation', affords a means of editing Web page content'on-the-fly'between the... more
This paper describes a technique for interceding between users and the information that they browse. This facility, that we term'dynamic annotation', affords a means of editing Web page content'on-the-fly'between the source Web server and the requesting client. Thereby, we have a generic way of modifying the content displayed to local users by addition, removal or reorganising any information sourced from the World-Wide Web, whether this derives from local or remote pages. For some time, we have been exploring the scope for ...
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Abstract. Transaction services offered by public authorities vary from simple forms with few fields to multi-form compound documents with hundreds of input areas. In the latter case, field placement within forms is of particular... more
Abstract. Transaction services offered by public authorities vary from simple forms with few fields to multi-form compound documents with hundreds of input areas. In the latter case, field placement within forms is of particular importance for facilitating the filling and error correction processes. In this paper we present an approach to improving the form layout by exploiting validation checks that are usually associated with electronic forms, as well as semantic information that may be attached to form fields by designers.
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The paper presents an integrated environment which enables museum personnel to catalogue and at the same time publish online museum exhibits. The system is based on international standards and is highly customisable to cater the needs of... more
The paper presents an integrated environment which enables museum personnel to catalogue and at the same time publish online museum exhibits. The system is based on international standards and is highly customisable to cater the needs of a variety of museum types. Moreover, the underlying database allows storing for the same exhibit documentations for different audiences and in multiple languages, while it is extendable to accommodate new media types, languages, exhibits and information categories. The ...
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The paper presents the results of a study on how historians conduct research in a historical archive, and the methodologies they use while searching. Historic research involves finding, using and correlating information within primary and... more
The paper presents the results of a study on how historians conduct research in a historical archive, and the methodologies they use while searching. Historic research involves finding, using and correlating information within primary and secondary sources, in order to understand past events. Historians conduct research systematically, by examining past events to renew the past; historic research may involve interpretation to recapture the nuances, personalities, and ideas that have influenced these events, and the expected ...
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Abstract: In the past years, a number of implementations of temporal DBMSs has been reported. Most of these implementations share a common feature, which is that they have been built as an extension to a snapshot DBMS. In this paper, we... more
Abstract: In the past years, a number of implementations of temporal DBMSs has been reported. Most of these implementations share a common feature, which is that they have been built as an extension to a snapshot DBMS. In this paper, we present three alternative ...
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Public transaction services (such as e-forms), although perceived the future of e-government have not yet realised their full potential. E-forms have a significant role in e-government, as they are the basis for realising most of the... more
Public transaction services (such as e-forms), although perceived the future of e-government have not yet realised their full potential. E-forms have a significant role in e-government, as they are the basis for realising most of the twenty public services that all European Union member states have to provide to their citizens and businesses. The aim of this paper is to
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Research Interests: Computer Science, Informatics, Service Oriented Architecture, Telecommunications, Business Process Management, and 10 moreTechnology Management, Web Services, Semantic Web, Quality of Service, Process Design, Exception Handling, Business Process, Web Service, Data Handling, and Business process design
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An extendable ontology for user profiles. Files can be retrieved from the link below.
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Research Interests: History, Information Retrieval, Ontology, Visualization, Information Management, and 13 moreHeuristics, Information Visualization, Digital Content, Data Visualization, Digital Library, Ontologies, Automation, Historical Research, Incomplete Information, Th, Historical Data, User Study, and Data Storage Management in Cloud
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Abstract. In this study we present a technique for the parallel optimisation of join queries that uses the offered coarse-grain parallelism of the underlying architecture in order to reduce the CPU-bound optimisation overhead. The... more
Abstract. In this study we present a technique for the parallel optimisation of join queries that uses the offered coarse-grain parallelism of the underlying architecture in order to reduce the CPU-bound optimisation overhead. The optimisation technique performs an almost ...
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Research Interests: Computer Science, Computer Architecture, Informatics, Service Oriented Architecture, Independent Component Analysis, and 12 moreWeb Services, Ontologies, User interfaces, Open Systems, Web Service, Availability, Composite Web Service, Blackboard Architecture, Point of View, Internet, User Interaction, and LIFE EVENT
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Int. J. Electronic Governance, Vol. 1, No. 3, 2008 ... An active blackboard for service discovery, composition and execution ... Department of Computer Science and Technology, Terma Karaiskaki, Tripoli, 22100, Greece E-mail: gl@uop.gr... more
Int. J. Electronic Governance, Vol. 1, No. 3, 2008 ... An active blackboard for service discovery, composition and execution ... Department of Computer Science and Technology, Terma Karaiskaki, Tripoli, 22100, Greece E-mail: gl@uop.gr E-mail: costas@uop.gr * ...