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MESON: A Platform for Optimized Cross-Slice Communication on Edge Computing Infrastructures
No full textIn the dawn of the 6G era, evolving service ecosystems raise the need for cross-service interactions. Existing resource/service orchestration frameworks are oblivious to such cross-service interactions, since they tend to orchestrate services independent to each other. In this respect, we stress on the need for optimized cross-service communication, and more specifically, for optimized cross-slice communication (CSC). To this end, we present a CSC orchestration platform, namely MESON, which fulfills all main CSC requirements, such as the discovery of CSC-enabled services, the selection of the most suitable (edge) computing infrastructure, and also the establishment and configuration of CSC in a secure and policy-compliant manner. MESON has been designed and built as an extension of the ETSI NFV MANO framework. Relying on MESON as a proof-of-concept for CSC, we present evaluation results from various performance and scalability tests, and further uncover significant gains from optimized CSC in relation to video streaming and Industry 4.0 use cases.10493224933
Modular architecture providing convergent and ubiquitous intelligent connectivity for networks beyond 2030
No full textThe transition of the networks to support forthcoming beyond 5G (B5G) and 6G services introduces a number of important architectural challenges that force an evolution of existing operational frameworks. Current networks have introduced technical paradigms such as network virtualization, programmability and slicing, being a trend known as network softwarization. Forthcoming B5G and 6G services imposing stringent requirements will motivate a new radical change, augmenting those paradigms with the idea of smartness, pursuing an overall optimization on the usage of network and compute resources in a zero-trust environment. This paper presents a modular architecture under the concept of Convergent and UBiquitous Intelligent Connectivity (CUBIC), conceived to facilitate the aforementioned transition. CUBIC intends to investigate and innovate on the usage, combination and development of novel technologies to accompany the migration of existing networks towards Convergent and Ubiquitous Intelligent Connectivity (CUBIC) solutions, leveraging Artificial Intelligence (AI) mechanisms and Machine Learning (ML) tools in a totally secure environment.3369370
NFV-Based Scheme for Effective Protection against Bot Attacks in AI-Enabled IoT
No full textThe Internet of Things (IoT) is the upcoming network that aspires to interconnect "things" to each other and to the Internet. Many such "things" like smart devices and wireless sensors are already connected to the Internet, improving human life worldwide. These things can also have artificial intelligence, providing many capabilities to their users. However, such IoT-based devices hide risks since they are usually small devices with constrained resources, and hence do not have sufficient built-in security mechanisms. In addition, the increase of such devices with geometric regression worries network administrators who must take countermeasures to restrict and eliminate attackers who aim to turn the IoT into a Botnet of Things network, using compromised devices as bots to unleash distributed-denial-of-service and man-in-the-middle attacks, or/and spread various types of malware. Thus, they can have unauthorized access and steal very sensitive data from users for malicious purposes. In this article, we highlight the problem caused by the uncontrolled development of insecure IoT-based devices and describe an effective network functions virtualization infrastructure in combination with emerging technologies that could provide smart management and enhanced protection against botnet attacks.51919
Return and volatility spillovers in twelve Eastern European countries, 2006-2015
No full textThis study investigates return and volatility spillovers in the stock markets of 12 Eastern European countries using an augmented univariate AR-EGARCH model. The study introduces two additional explanatory variables: the change in exchange rates of each country’s domestic currency to the USD and the return of the S&P 500 index. The previous period's figures were preferred for both parameters. These newly introduced variables are used not only separately, but also in conjunction with and without the liquidity factor. Thus, a ‚bouquet’ of eight parallel equations for each sample is formed. According to the empirical results, return and volatility spillovers are confirmed for most cases, regardless of the chosen approach. Furthermore, the expected positive sign for the coefficients regarding the exchange rates and the S&P 500 index is verified most of the time. Moreover, the leverage effect was observed in several cases. In addition, the outcomes illustrate that the trading volume’s coefficient mainly carries a positive sign and that this variable accounts for spillover effects in return and volatility. Overall, it can be concluded that the developed univariate AR-EGARCH models successfully capture the effects of volatility transmissions in the examined stock markets.12319121
Shift scheduling in multi-item production lines: a case study of a mineral water bottling company
No full textIt is well-known that the use of quantitative methods and modern analytics by companies in competitive markets is of vital importance both for their efficiency and financial profit. This study presents a novel, mathematical production-planning model for a real-world production optimization problem of a company located in Northern Greece. The company produces non-alcoholic soft drinks and needs to continuously allocate its human resources in order to have the optimum profit. Therefore, the objective of the model is the minimization of the company's idle human-hours subject to the fulfillment of the demand of customers. As algebraic modeling languages are well-suited for prototyping and developing optimization models, this production planning, mathematical model is implemented in Python v3.7.3 and solved using Gurobi solver v9.0. Furthermore, we also describe the competitive advantages offered by our quantitative approach and the initial allocation plan by the company.91758
Sustainable Supply Chain Management in the Food Industry: A Conceptual Model from a Literature Review and a Case Study
No full textThe purpose of this study is twofold: firstly, to provide a literature review of sustainable supply chain management (SSCM) critical factors, practices and performance; and secondly, to develop a comprehensive and testable model of SSCM in the food industry. The research conducted comprises a literature review and a case study. The literature review findings propose a theoretical framework linking SSCM critical factors, practices and performance. The case study comprises two sustainability leaders in the Greek food supply chain in order to investigate the three SSCM constructs. A new set of pioneering SSCM practices in the Greek food industry is identified, including daily conversation, local sourcing and HR investments. The end result of this research proposes a testable model that sheds light on SSCM in the food industry and is based on a set of propositions.1115229
Systematizing Business Process Redesign Initiatives with the BPR:Assessment Framework
No full textBusiness process redesign (BPR) has emerged as a widely accepted practice within organizations for delivering better products and services and ensuring measurable benefits. Despite the adoption of BPR, it largely remains the result of a creative process and there is a lack of approaches for evaluating the potential impact of a BPR method before investing in its implementation. This means that BPR initiatives are selected based on ‘black-box’ generic options that are not explicitly tailored to the culture, structure, and existing processes of the organization. This paper aims to address this gap by introducing the BPR: Assessment Framework, a conceptual model based on Design Science Research Process (DSRP). The framework is intended to assess the BPR capacity of process models based on their plasticity and external quality. The usability of the framework is presented in the following manner: (a) through the demonstration of the framework using a data-intensive workflow optimization method as an end-to-end paradigm, and (b) the BPR capability assessment of 15 business process models from literature, to better demonstrate the benefits of omitting ineligible models prior to BPR application. The categorization of the redesign capability of models was based on a tested cluster analysis method using the k-means algorithm. Based on the findings, a considerable number of process models proved to be either overly constrained for the application of redesign heuristics or did not possess the required external quality to be redesigned. The contribution of the approach lies in the fact that the framework can also be extended to apply systematic BPR to eligible BPs. The framework can serve as a reliable measurement of the redesign capacity of candidate process models and as an essential part of a systematic methodology for increased BPR effectiveness.17242022 IEEE 24th Conference on Business Informatics (CBI
The impact of gender diversity on shareholder wealth: Evidence from European bank M&A
No full textWe explore the association between board gender diversity and shareholder value creation. Specifically, we investigate the impact of gender diversity on the economic impact of bank mergers and acquisitions (M&A). We employ a multi-year sample of M&A announced by European listed banks and find that: (i) the presence of women on the board of directors has a positive and statistically significant effect on acquirer gains; and (ii) boards with three or more women, or where women represent more than 25% of the board, have a stronger impact on acquirer gains than in the opposite case, consistent with critical mass theory. Moreover, banks with a critical mass of female directors perform better in undertaking value-enhancing M&A after the global financial crisis. Policy makers and practitioners could benefit from the findings by exploiting the advantages of board heterogeneity in terms of gender.6010102
User-Generated Content in Social Media: A Twenty-Year Bibliometric Analysis in Hospitality
No full textThis article aims to present a bibliometric analysis regarding social media platforms and User-Generated Content (UGC) in hospitality. One hundred fifty-one peer-reviewed articles were analyzed using Webster’s and Watson’s (2002) methodology, a concept-driven methodology that helps analyze different concepts and contexts of a research field. Articles classified into five areas and a bibliometric analysis were presented to discuss the publication year, journals and publishers, authors, number of citations, research method implemented, social networking and users’ perceived value, user-generated content and travel planning, e-Word-of-Mouth (e-WOM) and brand image building, and hotel performance. The findings of this study showed that the number of studies in this field has increased over the last decade. However, exploration of the subject needs to be promoted (particularly experimental) because research in hospitality social media is still in the early phases on the grounds that publications concentrate on explicit subjects, regions, and sources of publication.131257
A note on the relative productivity drivers of economists: a probit/logit approach for six European countries
No full textWe examine the drivers of research performance of 1431 economists from six European countries. Data from the Scopus database are collected. We compare the relative performance of economists from three northern European countries: Belgium, Denmark and Germany with three from the south: Greece, Italy and Portugal. Relative performance is measured as the deviation from the country average in both citations and papers. The dependent variables take the value of 1 if the productivity of the researcher is above the country average and 0 if it is below. Probit/logit analysis is employed and marginal effects are estimated to examine the significance of factors like the country of their PhD studies, gender and inbreeding at the national level. A US PhD or a German PhD affects negatively the relative productivity of German economists. Inbreeding at the national level (locally trained economists) reduces productivity among Greek, Italian and Portuguese economists. Gender is significant in the case of Denmark, Germany and Italy, but it does not affect productivity in Belgium, Greece and Portugal.555