Giannis Tzimas

University of Peloponnese | UOP · Department of Electrical & Computer Engineering

Multiclass classification is one of the most popular machine learning tasks. The main focus of this paper is to classify occupations according to the International Standard Classification of Occupations (ISCO) using a weights and structure determination (WASD)-based neural network. In general, WASD-trained neural networks are known to overcome the...

Blockchain is a linearly linked, distributed, and very robust data structure. Originally proposed as part of the Bitcoin distributed stack, it found a number of applications in a number of fields, most notably in smart contracts, social media, secure IoT, and cryptocurrency mining. It ensures data integrity by distributing strongly encrypted data i...

The management of acute gout in the hospital setting may be challenging since most patients are elderly with multiple unstable comorbidities. However, there are no prospective clinical trials for hospitalized patients with gout to guide optimal management. Evidence indicates that steroids or adrenocorticotropic hormone (ACTH) may be effective and s...

With the advances in natural language processing and big data analytics, the labor market community has introduced the emerging field of Labor Market Intelligence (LMI). This field aims to design and utilize Artificial Intelligence (AI) algorithms and frameworks to analyze data related to the labor market information for supporting policy and decis...

This work aims to contribute to the field of COVID-19 pandemic analysis. In this research we applied a twofold analysis that focused initially on the country general social-economic and medical characteristics and on top of that in a second level exploring the correlations to the characteristics that affect COVID-19 patients’ mortality level. The a...

Tensor clustering is a knowledge management technique which is well known as a major algorithmic and technological driver behind a broad applications spectrum. The latter ranges from multimodal social media analysis and geolocation processing to analytics tailored for large omic data. However, known exact tensor clustering problems when reduced to...

We use administrative, survey, and online vacancy data to analyze the short-term labor market impacts of the COVID-19 lockdown in Greece. We find that flows into unemployment have not increased; in fact, separations were lower than would have been expected given trends in recent years. At the same time, employment was about 12 percent lower at the...

Content Management Systems (CMSs) play an increasingly important role in the evolution of the World Wide Web, since almost half of the websites today use some form of CMS as their main development platform. CMSs provide development teams with standardized software platforms that significantly facilitate and speed up Web development, while maintaini...

Blockchain is a linearly linked, distributed, and very robust data structure. Originally proposed as part of the Bitcoin distributed stack, it can be applied in a number of fields, most notably in smart contracts, social media, secure IoT, and cryptocurrency mining. It ensures data integrity by distributing strongly encrypted data in widely redunda...

Imagine that we have a highly competing virus that is spreading over a (e.g., social) network where users have different sensitivity/interest against it. A virus may be anything that has a “spreading” behavior such as a rumor, a social media trend or even an infectious disease. Is it possible to predict the outcome in such a viral phenomenon and co...

In the original publication, part figures were incorrectly positioned in Figure 2. The correct figure is given below.

Fibonacci numbers appear in numerous engineering and computing applications including population growth models, software engineering, task management, and data structure analysis. This mandates a computationally efficient way for generating a long sequence of successive Fibonacci integers. With the advent of GPU computing and the associated special...

In this work, we present an approach for supporting the identification of domain-specific design patterns based on domain’s ontology, since the latter encapsulates the knowledge about the problem domain. More specifically, the proposed approach automatically analyzes the designs of a collection of domain-specific websites in terms of all the recurr...

Blockchain is a linearly linked, distributed, and very robust data structure. Originally proposed as part of the Bitcoin distributed stack, it found a number of applications in a number of fields, most notably in smart contracts, social media, secure IoT, and cryptocurrency mining. It ensures data integrity by distributing strongly en-crypted data...

Structural resilience is an inherent, paramount property of real world, massive, scale free graphs such as those typically encountered in brain networks, protein-to-protein interaction diagrams, logistics and supply chains, as well as social media among others. This means that in case a small fraction of edges or even vertices with their incident e...

Over the last decade, the vast explosion of Internet data has fueled the development of Big Data management systems and technologies. The huge amount of data in combination with the need for records linkage under privacy perspective, has led us to current study. To this direction, we describe Privacy Preserving Record Linkage problem based on Bloom...

Maritime surveillance operations are needed worldwide to monitor and reassure safety and security across the seas. Numerous devices are employed in order to provide situational awareness of the vast sea. Lots of different technologies are involved to provide multiple views and clarify maritime conditions at a given time and place, however making in...

Multimodal social networks are omnipresent in Web 2.0 with virtually every human communication action taking place there. Nonetheless , language remains by far the main premise such communicative acts unfold upon. Thus, it is statutory to discover language communities especially in social data stemming from historically multilingual countries such...

A k-nearest neighbor (kNN) query determines the k nearest points, using distance metrics, from a given location. An all k-nearest neighbor (AkNN) query constitutes a variation of a kNN query and retrieves the k nearest points for each point inside a database. Their main usage resonates in spatial databases and they consist the backbone of many loca...

Sentiment Analysis on Twitter Data is indeed a challenging problem due to the nature, diversity and volume of the data. People tend to express their feelings freely, which makes Twitter an ideal source for accumulating a vast amount of opinions towards a wide spectrum of topics. This amount of information offers huge potential and can be harnessed...

Domain-specific design patterns provide developers with proven solutions to common design problems that arise, particularly in a target application domain, facilitating them to produce quality designs in the domain contexts. However, research in this area is not mature and there are no techniques to support their detection. Towards this end, we pro...

Genome informatics deals with informatics tools used in molecular biology, and it is an important scientific discipline that emerged in the postgenomic era from developments in the field of human genomics. Advances in the understanding of the genetic etiology of human disorders, coupled with advances in technology, have led to the identification of...

FINDbase (http://www.findbase.org) is a comprehensive data repository that records the prevalence of clinically relevant genomic variants in various populations worldwide, such as pathogenic variants leading mostly to monogenic disorders and pharmacogenomics biomarkers. The database also records the incidence of rare genetic diseases in various pop...

Most catalogues of web design patterns contain patterns of general purpose, making it difficult for developers to properly apply them. This has led to the advent of domain-specific design patterns, encapsulating design experience which is in alignment with the natural constraints of a particular domain. Towards this end, we have developed a methodo...

The key success factor for modern web applications is their acceptance by the end-users which heavily depends on the quality of the user experience that they offer to them. Users require applications designed in such a way that it enables them to learn the supported functionalities easily, so that they can quickly find the information that they are...

Sentiment analysis on Twitter data has attracted much attention recently. One of the system's key features, is the immediacy in communication with other users in an easy, user-friendly and fast way. Consequently, people tend to express their feelings freely, which makes Twitter an ideal source for accumulating a vast amount of opinions towards a wi...

This paper addresses the inspection and evaluation of design reuse in the conceptual schema of CMS-based Web applications in order to improve their design quality. We have utilized WebML as the design platform of our approach and we capture design reuse by detecting all the recurrent design structures within the hypertext schema of an application....

Cloud Computing has brought a great change in the way information is stored and applications run. In order for one or more clusters to work as a cloud we need a middleware framework, such as Apache Hadoop [17], that provides reliability, scalability and distributed computing. Once the infrastructure has been established, a software framework can be...

The polygon retrieval problem is, in essence, the problem of preprocessing a set of n 2-dimensional points, so than given a special ContainedIn spatial query, the subset of points falling inside the polygon can be reported efficiently. Such queries find great applicability in areas such as computer graphics, spatial databases and GIS applications....

Sentiment analysis (or opinion mining) on Twitter data has attracted much attention recently. One of the system's key features, is the immediacy in communication with other users in an easy, user-friendly and fast way. Consequently, people tend to express their feelings freely, which makes Twitter an ideal source for accumulating a vast amount of o...

A k-nearest neighbor (kNN) query determines the k$nearest points, using distance metrics, from a given location. An all k-nearest neighbor (AkNN) query constitutes a variation of a kNN query and retrieves the k nearest points for each point inside a database. Their main usage resonates in spatial databases and they consist the backbone of many loca...

This paper addresses the automated design quality evaluation of Web applications built on a CMS platform by inspecting their conceptual model under the viewpoint of consistent design reuse. We have utilized WebML as the design platform of the proposed methodology and we attempt to capture design reuse by detecting all the recurrent patterns within...

An improved Adaptive Neuro-Fuzzy Inference System (ANFIS) in the field of critical cardiovascular diseases is presented. The system stems from an earlier application based only on a Sugeno-type Fuzzy Expert System (FES) with the addition of an Artificial Neural Network (ANN) computational structure. Thus, inherent characteristics of ANNs, along wit...

Currently, Web quality research term mainly refers to the quality of content of web pages. There are some research efforts on Javascript code and CSS code quality metrics, but none for measuring metrics of HTML5 code and estimating its quality and quantity. Towards this direction the aim of this work is to determine what characteristics of HTML5 co...

The polygon retrieval problem is, in essence, the problem of preprocessing a set of n 2-dimensional points, so than given a special ContainedIn spatial query, the subset of points falling inside the polygon can be reported efficiently. Such queries find great applicability in areas such as computer graphics, spatial databases and GIS applications....

Dynacargo, a research project under implementation, aims to change supply chain management, as the hauled goods are at the center of attention instead of vehicles, as in traditional management approaches. At the same time Dynacargo manages both delivery and collection cycles. Dynacargo aims at developing a near real-time monitoring system that moni...

The advent of the emerging social technologies has transformed the Web to a place where users can turn for social interaction, content consumption and opinion making. As social networks are becoming more ubiquitous, they set new requirements to the needs of modern enterprises which now need web applications that can incorporate social networking fe...

We present a novel mobile solution to provide efficient services for data fusion towards augmenting maritime safety. It is the first, to the best authors knowledge, complex and integrated fusion of data coming from multiple mobile and typical tracking sensors (e.g. Low weight/high performance radar, position transmission mechanisms and electro-opti...

The problem of top viewing human tracking in a closed environment, such as is the area of a shopping centre is a challenging one. In this paper we test a number of Kalman and simple particles filters-based algorithms for solving the visual tracking problem. Although results obtained from the experiments that we have conducted are promising and can...

Dynacargo is an ongoing research project that introduces a breakthrough approach for cargo management systems, as it places the hauled cargos in the center of a haulage information management system, instead of the vehicle. Dynacargo attempts to manage both distribution and collection processes, providing an integrated approach. This paper presents...

Cloud providers store on databases for their users an increasing large number of data. These data are most of the time multi-dimensional and so applications using these data must have some type of indexing on them to perform queries on them efficiently. This indexing scheme must be scalable and also has low maintenance cost. The main task of this p...

Suppose we have a virus or one competing idea/product that propagates over a multiple profile (e.g., social) network. Can we predict what proportion of the network will actually get "infected" (e.g., spread the idea or buy the competing product), when the nodes of the network appear to have different sensitivity based on their profile? For example,...

This study presents the utilization of a Hybrid Education Platform for the realization of a versatile blended learning model oriented to computer engineering and science educators. Furthermore, a data mining approach is introduced to analyze the questionnaires that learners submit concerning the learning activities they have participated in. Specif...

Motivation: An autoimmune disorder occurs when the immune system mistakenly attacks and destroys its own healthy body tissues. The initiation of a geoepidemiological database, for recording autoimmune incidents with a focus to clinical manifestations, demographic parameters and geographic background is crucial to detect correlations. Results: Th...

In last decades, Bioinformatics has become an emerging field of science with a wide variety of applications in many research areas. The primary goal of bioinformatics is to detect useful biological knowledge hidden under the large volumes of DNA/RNA sequences and structures, literature and other biological and biomedical data, to gain a greater ins...

During last decades, bioinformatics has proven to be an emerging field of research leading to the development of a wide variety of applications. The primary goal of bioinformatics is to detect useful knowledge hidden under large volumes biological and biomedical data, gain a greater insight into their relationships and, therefore, enhance the disco...

Background/aims: Pharmacogenomics aims to rationalize drug use by minimizing drug toxicity and/or by increasing drug efficacy. A large number of genomic markers have been correlated with variable drug responses and severity of adverse drug reactions. Although a number of these drugs bear pharmacogenomic information in their labels--approved by reg...

A k-nearest neighbor (kNN) query determines the k nearest points, using distance metrics, from a given location. An all k-nearest neighbor (AkNN) query constitutes a variation of a kNN query and retrieves the k nearest points for each point inside a database. Their main usage resonates in spatial databases and they consist the backbone of many loca...

The users search mainly diverse information from several topics and their needs are difficult to be satisfied from the techniques currently employed in commercial search engines and without intervention from the user. In this paper, a novel framework is presented for performing re-ranking in the results of a search engine based on feedback from the...

The widespread use of the Internet caused the rapid growth of data on the Web. But as data on the Web grew larger in numbers, so did the perils due to the applications of data mining. Privacy preserving data mining (PPDM) is the field that investigates techniques to preserve the privacy of data and patterns. Knowledge Hiding, a subfield of PPDM, ai...

In recent IoT (Internet of Things) and Web 2.0 technologies, a critical problem arises with respect to storing and processing the large amount of collected data. In this paper we develop and evaluate distributed infrastructures for storing and processing large amount of such data. We present a distributed framework that supports customized deployme...

A $k$-nearest neighbor ($k$NN) query determines the $k$ nearest points, using distance metrics, from a specific location. An all $k$-nearest neighbor (A$k$NN) query constitutes a variation of a $k$NN query and retrieves the $k$ nearest points for each point inside a database. Their main usage resonates in spatial databases and they consist the back...

HbVar (http://globin.bx.psu.edu/hbvar) is one of the oldest and most appreciated locus-specific databases launched in 2001 by a multi-center academic effort to provide timely information on the genomic alterations leading to hemoglobin variants and all types of thalassemia and hemoglobinopathies. Database records include extensive phenotypic descri...

Staying tuned to the trends in a certain domain has extremely dynamic and potential applications in many areas. For example, business analysts need to know the current solutions used for attracting customers in order to decide on the most appropriate marketing strategy. Mea