Technological Educational Institute of Kavala
Kavala, Greece

The Eastern Macedonia & Thrace Institute of Technology is a public institute providing university-level education in Eastern Macedonia and Thrace. The institute has three campuses; the main campus in St. Lukas, Kavala, and additional campuses in Drama and Didymoteicho, Evros regional unit. The TEI of Kavala has 13,500 registered students, ranking seventh among the 16 technological educational institutes in Greece in terms of students. Wikipedia.

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Delias P.,Technological Educational Institute of Kavala
Industrial Management and Data Systems | Year: 2017

Purpose - The purpose of this paper is to manifest a method that exploits process analytics to discover critical knowledge for a business process. This knowledge eventually answers to the question if process behavior can suggest which activities should be outsourced to get the performance improved. Design/methodology/approach - The author linked waste sources to process behavioral patterns, and adopted the positive deviance paradigm to highlight compelling behaviors. Various analytic tools (generalized regression, clustering, etc.) were used to provide recommendations. Findings - By outsourcing small parts of the process, significant process improvement is expected. Evidence-based process analytics can effectively support the relevant decisions. Research limitations/implications - The author had no access to the relevant policy makers (process owners). Originality/value - The author proposed an operationalization of concepts that connects process behavior to waste sources. The author presented the use of positive deviance as a guide for waste elimination projects.

Kyzas G.Z.,Aristotle University of Thessaloniki | Kyzas G.Z.,Technological Educational Institute of Kavala | Kostoglou M.,Aristotle University of Thessaloniki
Materials | Year: 2014

One of the most serious environmental problems is the existence of hazardous and toxic pollutants in industrial wastewaters. The major hindrance is the simultaneous existence of many/different types of pollutants as (i) dyes; (ii) heavy metals; (iii) phenols; (iv) pesticides and (v) pharmaceuticals. Adsorption is considered to be one of the most promising techniques for wastewater treatment over the last decades. The economic crisis of the 2000s led researchers to turn their interest in adsorbent materials with lower cost. In this review article, a new term will be introduced, which is called "green adsorption". Under this term, it is meant the low-cost materials originated from: (i) agricultural sources and by-products (fruits, vegetables, foods); (ii) agricultural residues and wastes; (iii) low-cost sources from which most complex adsorbents will be produced (i.e., activated carbons after pyrolysis of agricultural sources). These "green adsorbents" are expected to be inferior (regarding their adsorption capacity) to the super-adsorbents of previous literature (complex materials as modified chitosans, activated carbons, structurally-complex inorganic composite materials etc.), but their cost-potential makes them competitive. This review is a critical approach to green adsorption, discussing many different (maybe in some occasions doubtful) topics such as: (i) adsorption capacity; (ii) kinetic modeling (given the ultimate target to scale up the batch experimental data to fixed-bed column calculations for designing/optimizing commercial processes) and (iii) critical techno-economical data of green adsorption processes in order to scale-up experiments (from lab to industry) with economic analysis and perspectives of the use of green adsorbents. © 2014 by the authors; licensee MDPI, Basel, Switzerland.

Akoumianakis D.,Technological Educational Institute of Kavala
Journal of Enterprise Information Management | Year: 2014

Purpose: The purpose of this paper is to investigate boundary spanning tactics in a cross-organizational virtual alliance and discuss the analytical value of "digging" into technology for excavating boundaries and understanding their dynamic and emergent features. Design/methodology/approach: Although boundaries, their role and implications have been extensively investigated across a variety of online settings, the results are inconclusive as to the features of technology that create, dissolve or re-locate boundaries. This is attributed to the fact that in most cases technology is addressed as a black box - a discrete artefact of practice - without seeking justification for the inscribed functions that enable or constrain use. The paper overcomes these shortcomings by analysing digital trace data compiled through a virtual ethnographic assessment of a cross-organizational tourism alliance. Data comprise electronic traces of online collaboration whose interpretive capacity is augmented using knowledge visualization techniques capable of revealing dynamic and emergent features of boundary spanning. Findings: Boundary spanning in virtual settings entails micro-negotiations around several types of boundaries. Some of them are either enforced by or inscribed into technology, while others are enacted in practice. Knowledge visualization of digital trace data allows "excavation" of these boundaries, assessment of their implications on distributed organizing of online ensembles and discovery of "hidden" knowledge that drives boundary spanning tactics of collaborators. Practical implications: In cross-organizational collaborative settings, boundary spanning represents an enacted capability stemming from the intertwining between material and social/collective agencies. Consequently, boundaries surface as first class design constructs, directing design attention not only to features inscribed in technology (i.e. user profiles, registration mechanisms, moderation policies) but also the way such features are appropriated to re-shape, re-locate or dissolve boundaries. Originality/value: An empirical data pool compiled through virtual ethnographic assessment of online collaboration is revisited and augmented with knowledge visualization techniques that enhance the interpretive capacity of the data and reveal "hidden" aspects of the collaborators' boundary spanning behaviour and tactics. © Emerald Group Publishing Limited.

Konguetsof A.,Technological Educational Institute of Kavala
Journal of Mathematical Chemistry | Year: 2010

With this paper, a new algorithm is developed for the numerical solution of the one-dimensional Schrödinger equation. The new method uses the minimum order of the phase-lag and its derivatives. Error analysis and the numerical results illustrate the efficiency of the new algorithm. © 2009 Springer Science+Business Media, LLC.

Papadakis S.E.,Technological Educational Institute of Kavala | Kaburlasos V.G.,Technological Educational Institute of Kavala
Information Sciences | Year: 2010

Linear models are preferable due to simplicity. Nevertheless, non-linear models often emerge in practice. A popular approach for modeling nonlinearities is by piecewise-linear approximation. Inspired from fuzzy inference systems (FISs) of Tagaki-Sugeno-Kang (TSK) type as well as from Kohonen's self-organizing map (KSOM) this work introduces a genetically optimized synergy based on intervals' numbers, or INs for short. The latter (INs) are interpreted here either probabilistically or possibilistically. The employment of mathematical lattice theory is instrumental. Advantages include accommodation of granular data, introduction of tunable nonlinearities, and induction of descriptive decision-making knowledge (rules) from the data. Both efficiency and effectiveness are demonstrated in three benchmark problems. The proposed computational method demonstrates invariably a better capacity for generalization; moreover, it learns orders-of-magnitude faster than alternative methods inducing clearly fewer rules. © 2010 Elsevier Inc. All rights reserved.

Krinidis S.,Technological Educational Institute of Kavala | Chatzis V.,Technological Educational Institute of Kavala
IEEE Transactions on Image Processing | Year: 2010

This paper presents a variation of fuzzy c-means (FCM) algorithm that provides image clustering. The proposed algorithm incorporates the local spatial information and gray level information in a novel fuzzy way. The new algorithm is called fuzzy local information C-Means (FLICM). FLICM can overcome the disadvantages of the known fuzzy c-means algorithms and at the same time enhances the clustering performance. The major characteristic of FLICM is the use of a fuzzy local (both spatial and gray level) similarity measure, aiming to guarantee noise insensitiveness and image detail preservation. Furthermore, the proposed algorithm is fully free of the empirically adjusted parameters (a, a;g, a;s, etc.) incorporated into all other fuzzy c-means algorithms proposed in the literature. Experiments performed on synthetic and real-world images show that FLICM algorithm is effective and efficient, providing robustness to noisy images. © 2010 IEEE.

Kyzas G.Z.,Technological Educational Institute of Kavala
Materials | Year: 2012

In this study, the decolorization of industrial textile wastewaters was studied in batch mode using spent "Greek coffee" grounds (COF) as low-cost adsorbents. In this attempt, there is a cost-saving potential given that there was no further modification of COF (just washed with distilled water to remove dirt and color, then dried in an oven). Furthermore, tests were realized both in synthetic and real textile wastewaters for comparative reasons. The optimum pH of adsorption was acidic (pH = 2) for synthetic effluents, while experiments in free pH (non-adjusted) were carried out for real effluents. Equilibrium data were fitted to the Langmuir, Freundlich and Langmuir-Freundlich (L-F) models. The calculated maximum adsorption capacities (Qmax) for total dye (reactive) removal at 25 °C was 241 mg/g (pH = 2) and 179 mg/g (pH = 10). Thermodynamic parameters were also calculated (ΔH0, ΔG0, ΔS0). Kinetic data were fitted to the pseudo-first, -second and -third order model. The optimum pH for desorption was determined, in line with desorption and reuse analysis. Experiments dealing the increase of mass of adsorbent showed a strong increase in total dye removal. © 2012 by the authors.

Kyzas G.Z.,Technological Educational Institute of Kavala
Materials | Year: 2012

This work aims to study the removal of Cu(II) and Cr(VI) from aqueous solutions with commercial coffee wastes. Materials with no further treatment such as coffee residues from café may act as adsorbents for the removal of Cu(II) and Cr(VI). Equilibrium data were successfully fitted to the Langmuir, Freundlich and Langmuir-Freundlich model (L-F). The maximum adsorption capacity of the coffee residues can reach 70 mg/g for the removal of Cu(II) and 45 mg/g for Cr(VI). The kinetic data were fitted to pseudo-first, -second and -third order equations. The equilibrium was achieved in 120 min. Also, the effect of pH on adsorption and desorption was studied, as well as the influence of agitation rate. Ten cycles of adsorption-desorption were carried out revealing the strong reuse potential of these low-cost adsorbents; the latter was confirmed from a brief economic approach. © 2012 by the authors.

Dermentzis K.,Technological Educational Institute of Kavala
Journal of Hazardous Materials | Year: 2010

Electrostatic shielding zones made of electrode graphite powder were used as a new type of ionic and electronic current sinks. Because of the local elimination of the applied electric field, voltage and current within the zones, ions are led inside them and accumulate there. The current sinks were implemented in electrostatic shielding electrodialysis of a simulated nickel plating rinse water containing 100 mg L -1 nickel and electrodeionization of a 0.001 M NiSO 4 solution with simultaneous electrochemical regeneration of the ion exchange resin beds. Pure water was obtained with a Ni 2+ ion concentration of less than 0.1 mg L -1 at a flow rate of 2.02 × 10 -4 dm 3 s -1 diluate stream and a current density of 30 A m -2. © 2009 Elsevier B.V. All rights reserved.

Kaburlasos V.G.,Technological Educational Institute of Kavala | Pachidis T.,Technological Educational Institute of Kavala
Information Fusion | Year: 2014

By "fusion" this work means integration of disparate types of data including (intervals of) real numbers as well as possibility/probability distributions defined over the totally-ordered lattice (R, ≤) of real numbers. Such data may stem from different sources including (multiple/multimodal) electronic sensors and/or human judgement. The aforementioned types of data are presented here as different interpretations of a single data representation, namely Intervals' Number (IN). It is shown that the set F of INs is a partially-ordered lattice (F, â̄) originating, hierarchically, from (R, ≤). Two sound, parametric inclusion measure functions σ:FN × FN → [0, 1] result in the Cartesian product lattice (FN, â̄) towards decision-making based on reasoning. In conclusion, the space (FN, â̄) emerges as a formal framework for the development of hybrid intelligent fusion systems/schemes. A fuzzy lattice reasoning (FLR) ensemble scheme, namely FLR pairwise ensemble, or FLRpe for short, is introduced here for sound decision-making based on descriptive knowledge (rules). Advantages include the sensible employment of a sparse rule base, employment of granular input data (to cope with imprecision/uncertainty/vagueness), and employment of all-order data statistics. The advantages as well as the performance of our proposed techniques are demonstrated, comparatively, by computer simulation experiments regarding an industrial dispensing application. © 2011 Elsevier B.V. All rights reserved.

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