Institutional Repository of Academic Research University of Macedonia
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Ranking econometric techniques using geometrical Benefit of Doubt
No full textA large part of economies around the world rely on stock markets. To predict stock prices or commodities, econometric techniques are used. Analysts choose the suitable econometric technique according to error measures which may create confusion, especially in the case where there is no preference amongst error measures. Therefore, there is no unique score to rank econometric techniques based on multiple error measures. To bridge this gap, we propose, a MCDM like methodology [geometrical Benefit of Doubt (BoD)] that considers econometric techniques as alternatives and error measures as criteria. A real application with 194 econometric techniques and 8 error measures is presented. The efficiency scores derived from geometrical BoD model provide better discrimination and experiemental results indicate that ARMA and ARCH models are ranked higher. The proposed geometrical BoD model is compared to similar geometrical MCDM formulations3301-241143
“AR The Gods of Olympus”: Design and Pilot Evaluation of an Augmented Reality Educational Game for Greek Mythology
No full textTeaching and learning theoretical subjects, such as History, although important, is considered by many students to be non-appealing. Alternative teaching approaches include the use of educational games and augmented reality (AR) applications, or more recently, AR educational games. Such games are considered to increase students’ interest for the subject and lead to better learning outcomes. However, studies about the use of AR educational games in the classroom are sparse and further research is necessary. In this article, we present an AR-enhanced educational game for teaching History (Greek Mythology) to 3rd grade Primary school students in Greece. The game, called “AR The Gods of Olympus” consists of three mini games: an AR game with the gods/goddesses of Olympus using narration; a memory game with cards depicting the gods and their symbols; and a quiz game. In order to study the effectiveness of the game and students’ experience and perceptions on it, a study was carried out with primary school students that used the game in classroom. The study utilized a pre-/post-test design, a brief questionnaire based on the MEEGA+ model for evaluating educational games, and observation of students during game playing. Students’ performance was improved after playing the game but the difference was not statistically significant, while the game was positively perceived by students. Especially the AR mini game raised students’ interest and as the students themselves stated helped them “learn while playing”.71
A Systematic Literature Review on Adaptive Supports in Serious Games for Programming
No full textThis paper reviews the research on adaptive serious games for programming regarding the implementation of their support systems. Serious games are designed to educate players in an entertaining and engaging manner. A key element in terms of meeting their educational goals is the presentation of the learning content through a support system. Recent developments in artificial intelligence, data analysis, and computing made the development of support systems that adapt to player individual characteristics possible. A systematic literature review is necessary to evaluate the efficiency of adaptive supports and examine the implementation approaches. This review identified 18 papers reporting evidence about the efficiency of the provided support and methods of development. A variety of techniques for presenting educational content was found, with text being the preferred type. Researchers employed data-driven approaches to model student knowledge levels and behavior such as Bayesian networks and questionnaires, with fuzzy logic being utilized most frequently. The efficiency of the supports, when compared with non-adaptive or traditional methods of teaching, was mostly positive, although this is not a decisive conclusion. Some papers did not provide empirical evidence or concluded no difference in efficiency. The limited number of articles in the field, together with the lack of a standard evaluation methodology, leads to the conclusion that further work needs to be carried out in the area.14527
It's about time: How to study intertemporal choice in systems design
No full textContext: Decision making pervades software and systems engineering. Intertemporal decisions involve trade-offs among outcomes at different points in time. They play a central role in systems design, as recognised since the inception of the software engineering (SE) field. They are also crucial for the sustainability of design decisions. However, temporal decision making is not adequately understood in SE. The field of Judgement and Decision Making (JDM) offers important empirical findings and research methods that could be utilised. Objective: This article establishes a baseline for studying how software professionals handle intertemporal choices. It examines how temporal distance affects choices in an example scenario, explores in what areas of software development such decisions can be found, and examines how systems design decisions can be characterised and studied as intertemporal. Method: We developed a method to study intertemporal choice in SE, based on an initial set of psychological theory grounded in JDM. We instantiated the method in a study to elicit responses to an intertemporal choice task followed by a Cognitive Task Analysis (CTA) interview. Results: We found that study participants overall tended to discount future outcomes, but individual participants varied wildly in how they valued present vs. future outcomes. They indicated several locations in which intertemporal choices occur in everyday software development. Based on these findings, and by reconciling our initial theory with existing JDM theory and results, we further developed and refined our theory and study method into a framework for studying intertemporal decision making in SE. Conclusions: To obtain a basis for more sustainable software systems design decisions, SE research should adopt a more comprehensive, detailed, and empirically consistent way of understanding and studying intertemporal choices. We provide suggestions for how future research could achieve practical methods that address essential characteristics of real-life systems design decisions.15810716
Logically-Centralized SDN-Based NDN Strategies for Wireless Mesh Smart-City Networks †
No full textThe Internet of Things (IoT) is a key technology for smart community networks, such as smart-city environments, and its evolution calls for stringent performance requirements (e.g., low delay) to support efficient communication among a wide range of objects, including people, sensors, vehicles, etc. At the same time, these ecosystems usually adopt wireless mesh technology to extend their communication range in large-scale IoT deployments. However, due to the high range of coverage, the smart-city WMNs may face different network challenges according to the network characteristic, for example, (i) areas that include a significant number of wireless nodes or (ii) areas with frequent dynamic changes such as link failures due to unstable topologies. Named-Data Networking (NDN) can enhance WMNs to meet such IoT requirements, thanks to the content naming scheme and in-network caching, but it necessitates adaptability to the challenging conditions of WMNs. In this work, we aim at efficient end-to-end NDN communication in terms of performance (i.e., delay), performing extended experimentation over a real WMN, evaluating and discussing the benefits provided by two SDN-based NDN strategies: (1) a dynamic SDN-based solution that integrates the NDN operation with the routing decisions of a WMN routing protocol; (2) a static one which based on SDN-based clustering and real WMN performance measurements. Our key contributions include (i) the implementation of two types of NDN path selection strategies; (ii) experimentation and data collection over the w-iLab.t Fed4FIRE+ testbed with real WMN conditions; (ii) real measurements released as open-data, related to the performance of the wireless links in terms of RSSI, delay, and packet loss among the wireless nodes of the corresponding testbed.1511
Recent Advances of Artificial Intelligence in Healthcare: A Systematic Literature Review
No full textThe implementation of artificial intelligence (AI) is driving significant transformation inside the administrative and clinical workflows of healthcare organizations at an accelerated rate. This modification highlights the significant impact that AI has on a variety of tasks, especially in health procedures relating to early detection and diagnosis. Papers done in the past imply that AI has the potential to increase the overall quality of services provided in the healthcare industry. There have been reports that technology based on AI can improve the quality of human existence by making life simpler, safer, and more productive. A comprehensive analysis of previous scholarly research on the use of AI in the health area is provided in this research in the form of a literature review. In order to propose a classification framework, the review took into consideration 132 academic publications sourced from scholarly sources. The presentation covers both the benefits and the issues that AI capabilities provide for individuals, medical professionals, corporations, and the health industry. In addition, the social and ethical implications of AI are examined in the context of the output of value-added medical services for decision-making processes in healthcare, privacy and security measures for patient data, and health monitoring capabilities.1313747
Digital innovation and entrepreneurship transformation through open data hackathons: Design strategies for successful start-up settings
No full textThe organization of open data hackathons or digital innovation competitions is a significant opportunity for nascent entrepreneurs to collaborate with external partners, promote new ideas and extend their applications to a new start-up. Prior studies have not thoroughly compared the execution of different strategies in many hackathons or digital innovation competitions. They only focus on the actions that the organizers of a specific hackathon have implemented or the challenges they have faced. Thus, the purpose of this paper is to examine goals and design strategies that contribute to the successful execution of open data hackathons and innovation competitions. Six case studies of open data hackathons and innovation competitions held between 2014 and 2018 in Thessaloniki have been explored to understand the co-ordination between the multiple stakeholders of these events and improve the execution of open data hackathons and innovation competitions. The outcomes indicate that the most critical design strategy was the involvement of mentors in the event and the level of support provided to nascent entrepreneurs to accelerate their creativity, develop applications and launch their prototypes on the market.6910247
Noisy Fading Channel Distributions Parameter Estimation and Reconstruction based on Truncation
No full textIn this paper, Rayleigh and Nakagami-m fading channels are considered that are positively correlated. The received signal statistics specifically mean and variance of sum of fading and noise variables in cases where fading distributions are considered ranging from zero to infinity compared to cases where the fading and noise distributions are truncated due to applying the energy criterion to each distribution are considered. Average number of required bits are derived by calculating Shannon entropy for each case investigated. The number of measurements required for distribution reconstruction based on CS reduced complexity method for each case are also computed. Furthermore, the Bit-Error-Rate (BER) curves for all respective cases are derived and directly compared. The results impose the effect of truncation on the quantification of variances as well as average number of bits as measures of uncertainty and number of measurements for reconstruction. The BER curves produced account for the Gaussian statistical assumption adopted. Applications to 5G communications are provided and future directions are highlighted.12610277
SQMetrics: An Educational Software Quality Assessment Tool for Java
No full textOver the years, various software quality measurement models have been proposed and
used in academia and the software industry to assess the quality of produced code and to obtain
guidelines for its improvement. In this article, we describe the design and functionality of SQMetrics, a tool for calculating object-oriented quality metrics for projects written in Java. SQMetrics provides the convenience of measuring small code, mainly covering academic or research needs. In this context, the application can be used by students of software engineering courses to make measurements and comparisons in their projects and gradually increase their quality by improving the calculated metrics. Teachers, on the other hand, can use SQMetrics to evaluate students’ Java projects and grade them in proportion to their quality. The contribution of the proposed tool is three-fold, as it has been: (a) tested for its completeness and functionality by comparing it with widely known similar tools, (b) evaluated for its usability and value as a learning aid by students, and (c) statistically tested for its value as a teachers’ aid assisting in the evaluation of student projects. Our findings verify SQMetrics’ effectiveness in helping software engineering students learn critical concepts and improve the quality of their code, as well as in helping teachers assess the quality of students’ Java projects and make more informed grading decisions.3455759
Neurobiological and pathophysiological concepts of Christfried Jakob (1866–1956) on language and aphasia: An English translation of two communications [1910,1932] and a modern perspective
No full textThe aim of the present article is to preserve, in English translation, two historical communications on aphasia and the pathophysiology of language by the neurobiologist Christfried Jakob (1866–1956) of Buenos Aires, and to place them in a modern perspective. The morphofunctional basis of human language and its pathology occupied Jakob's mind over three decades. His synthetic conclusions were based on the neuropathological examination of dozens of aphasic cases from the Hospital de Las Mercedes and the National Women's Psychiatric Hospital between 1906 and 1936. Special mention is made of the role of the cerebellum, the thalamus, and their connections with the cerebral cortex, and the language network. Current research and imaging studies support and elaborate that which Jacob presented so many years ago; many of his analyses and ideas are informative and remain relevant today.13310234