Girne American University is a university in Kyrenia, a city in the northern area of Cyprus. The university was founded in 1985 by Mr. Serhat Akpinar as an independent, non-profit institution of American-style higher education. Today, GAU is an international university with campuses in Cyprus, Istanbul, Washington D.C. , Hong Kong and Canterbury . Wikipedia.
Sadeghi K.,Girne American University
Structural Engineering and Mechanics | Year: 2015
A nonlinear Finite Element (FE) algorithm is proposed to analyze the Reinforced Concrete (RC) columns subjected to Cyclic Loading (CL), Cyclic Oriented Lateral Force and Axial Loading (COLFAL), Monotonic Loading (ML) or Oriented Pushover Force and Axial Loading (OPFAL) in any direction. In the proposed algorithm, the following parameters are considered: uniaxial behavior of concrete and steel elements, the pseudo-plastic hinge produced in the critical sections, and global behavior of RC columns. In the proposed numerical simulation, the column is discretized into two Macro-Elements (ME) located between the pseudo-plastic hinges at critical sections and the inflection point. The critical sections are discretized into Fixed Rectangular Finite Elements (FRFE) in general cases of CL, COLFAL or ML and are discretized into Variable Oblique Finite Elements (VOFE) in the particular cases of ML or OPFAL. For pushover particular case, a fairly fast converging and properly accurate nonlinear simulation method is proposed to assess the behavior of RC columns. The proposed algorithm has been validated by the results of tests carried out on full-scale RC columns. Copyright © 2015 Techno-Press, Ltd.
Bilgehan B.,Girne American University
IET Signal Processing | Year: 2015
This paper focuses on optimum representation for both linear and non-linear type signals which have a wide range of applications in the analysis and processing of real-world signals, that is, noise, filtering, audio, image etc. Accurate representation of signals, usually is not an easy process. The optimum representation is achieved by introducing exponential bases within multiplicative calculus which enables direct processing to reveal the unknown fitting parameters. Simulation tests confirm that the newly introduced models produce accurate results while using substantially less computation and provide support for applying the new model in the field of parametric linear, non-linear signal representation for processing. © The Institution of Engineering and Technology 2015.
Kostin A.,Girne American University |
Oz G.,Eastern Mediterranean University |
Haci H.,University of Kent
International Journal of Communication Systems | Year: 2014
A Petri-net-based simulation model of a wireless mobile ad hoc network is developed and studied. The model covers all the fundamental aspects of behaviour of such a network and uses a novel scheme of orientation-dependent (or sector-dependent) internode communication, with random states of links. The proposed scheme enables representation of reliability aspects of wireless communication, such as fading effects, interferences, presence of obstacles and weather conditions in a general and rather easy way. The simulation model was implemented in terms of a class of extended Petri nets to explicitly represent parallelism of events and processes in the WLAN as a distributed system. In the simulation, the behaviour of four fundamental performance metrics - packet delivery ratio, average number of hops, relative network traffic and end-to-end delay - were investigated with varying distance of transmission and different combinations of model parameters. Copyright © 2012 John Wiley & Sons, Ltd.
Dincer U.D.,Girne American University
International Journal of Stem Cells | Year: 2016
Endothelium represents a defense barrier and responds and integrates neuro humoral stimulus which describes as a compensatory mechanism. Endothelium formed with endothelial cells (ECs) and their progenitors. Endothelial progenitor cells (EPCs) represent minor subpopulation of mononuclear cells in the blood. During acute hypoxia, larger amount of EPCs mobilize into the peripheral blood and they directly contribute revascularization process. One of the subtypes of EPC is termed endothelial colony forming cells (ECFCs) which they possess de novo vessel-forming ability. The present study aims to investigate the role of hypoxia in EPCs functional and vessel-forming ability. Furthermore, it was investigated whether fetal exposure to a diabetic intrauterine environment influence EPCs adaptation ability. Human umbilical cord blood (HUCB) derived ECFCs were selected in all experimental procedures obtained from normal and gestational diabetes mellitus (GDM) subjects via in vitro cell culture methods. Early passage (<5) HUCB ECFCs obtain from GDM (n; 5) and control (n; 5) subjects were cultured with plates pre-coated with collagen in vitro 72 h hypoxic as well as normoxic condition. Endothelial, angiogenic and hypoxia associated gene specific primers designed to perform Real-time PCR. Senescenes assay conducted onto HUCB ECFCs to investigate their functional clonogenic ability. To quantify their vessel forming ability matrigel assay was applied. These data demonstrates that moderate hypoxia results increased vessel-forming ability and VEGFA expression in HUCB ECFCs obtained from control subjects. However, GDM caused to impede compensatory defense reaction against hypoxia which observed in control subjects. Thus, it illuminates beneficial information related future therapeutic modalities.
Sila I.,Girne American University
Electronic Commerce Research | Year: 2013
The objective of this study is to analyze the factors affecting the adoption of Internet-enabled business-to-business electronic commerce (B2B EC) and test their applicability in different contexts. We used 275 responses from an online survey of North American firms and tested our hypotheses with Multiple Regression and Analysis of Variance (ANOVA). We found that scalability is the biggest contributor to B2B EC usage. We also compared each adoption factor across adopters and nonadopters of B2B EC. Six of the nine adoption factors tested distinguished adopters of B2B EC from nonadopters. Then we analyzed the effects of these factors on adoption using several contextual variables, including firm size, firm type, management level of respondents, and country of origin of firms. The results showed that all of the contextual variables, except country of origin, influenced some of the adoption factors. Managers can use the findings of this study to understand which factors will most likely facilitate the implementation of B2B EC and be prepared to manage the effects of these factors on their initiatives more effectively. Many of the studies in this area have not tested the effects of contextual variables on B2B EC adoption. Thus, we contribute to the limited literature on this issue. The study shows that the technology-organization-environment (TOE) framework provides a strong foundation for the study of B2B EC. It also provides evidence that this framework is strengthened further when contextual variables are integrated into the theoretical model. © 2013 Springer Science+Business Media New York.
Sadeghi K.,Girne American University
International Journal of Civil Engineering | Year: 2011
An energy based damage index based on a new nonlinear Finite element (FE) approach applicable to RC structures subjected to cyclic, earthquake or monotonic loading is proposed. The proposed method is based on the evaluation of nonlinear local degradation of materials and taking into account of the pseudo-plastic hinge produced in the critical sections of the structure. A computer program is developed, considering local behavior of confined and unconfined concretes and steel elements and also global behavior and damage of reinforced concrete structures under cyclic loading. The segments located between the pseudoplastic hinges at critical sections and the inflection points are selected as base-models through simulation by the proposed FE method. The proposed damage index is based on an energy analysis method considering the primary half-cycles energy absorbed by the structure during loading. The total primary half-cycles absorbed energy to failure is used as normalizing factor. By using the proposed nonlinear analytical approach, the structure's force-displacement data are determined. The damage index is then calculated and is compared with the allowable value. This damage index is an efficient means for deciding whether to repair or demolish structures after an earthquake. It is also useful in the design of new structures as a design parameter for an acceptable limit of damage defined by building codes. The proposed approach and damage index are validated by results of tests carried out on reinforced concrete columns subjected to cyclic biaxial bending with axial force.
Daskin M.,Girne American University |
Tezer M.,Near East University
Tourism | Year: 2012
The purpose of this study was to examine the effects of scarcity of resources, favoritism, and organizational support as antecedents on organizational politics perceptions of frontline staff and the effect of these perceptions on their turnover intention in Cypriot hotels as its setting. For this study, a total number of 140 usable questionnaires were collected from frontline staff who was defined as all frontline supervisors from the front office, food&beverage, guest relations, and housekeeping departments working in three, four and five star hotels in North Cyprus. The hypothesized relationships were tested using SPSS 18 version through path analysis. The model test results indicated that scarce resources and favoritism are significant determinants of organizational politics perceptions. On the other hand, organizational support was found to be negatively related with organizational politics. The empirical result also demonstrated that frontline supervisors' politics perceptions exerted a positive effect on their turnover intentions. This research makes useful contributions to the current knowledge base by exclusively investigating the direct effect offavoritism on perceptions of organizational politics and indirect influence on turnover intention. Because favoritism practices have potential to paralyze the organizational justice and create distrustful working environment which makes real performers to engage in political games or quit the job.
Sila I.,Girne American University
International Journal of Electronic Business | Year: 2015
The objective of this study is to analyse previous research on the adoption and diffusion of business-to-business electronic commerce (B2B EC). The study focuses on case- And survey-based empirical research. We identified a total of 197 relevant studies and classified them using several categories. An analysis of these studies enabled us to discover a variety of issues in B2B EC adoption and diffusion research with respect to research objectives and methodologies, use of theory, adoption and diffusion factors, and B2B EC-performance relationships. We made a number of recommendations for future research in each of these areas. © 2015 Inderscience Enterprises Ltd.
Bahlouli K.,Girne American University |
Khoshbakhti Saray R.,Sahand University of Technology
Energy | Year: 2016
Energetic and exergetic analyses are performed for a proposed cogeneration cycle of heat and power. The cycle includes a STC (steam turbine cycle) to produce power and saturated steam, an AHT (absorption heat transformer) cycle to produce hot water and a HCCI (homogeneous charge compression ignition) engine as prime mover. Furthermore, the cooling water of the engine is used for heating purposes. The effect of variation of the cycle variables on the performance of the STC and AHT cycles are evaluated in details. The results show that the integrated system improves the energy utilization factor from 44.65% for the HCCI engine to 86.01% for the proposed system. Also, the exergy efficiency of the system increases from 39.49% for the HCCI engine to 48.56% for the proposed system. The maximum exergy destruction for the HCCI engine happens in the combustion chamber and for the STC occurs in turbine and for the case of the AHT cycle takes place in the absorber. Results of parametric study show that the exergy efficiency increases by increasing pressure ratio of the STC. The COP (coefficient of performance) of the AHT cycle increases as the condenser and absorber temperatures increase, but slightly decreases by increasing the evaporator temperature. © 2016 Elsevier Ltd.
Deniz Ulker E.,Girne American University |
Haydar A.,Girne American University
Advances in Electrical and Computer Engineering | Year: 2013
In real-world optimization problems, even though the solution quality is of great importance, the robustness of the solution is also an important aspect. This paper investigates how the optimization algorithms are sensitive to the variations of control parameters and to the random initialization of the solution set for fixed control parameters. The comparison is performed of three well-known evolutionary algorithms which are Particle Swarm Optimization (PSO) algorithm, Differential Evolution (DE) algorithm and the Harmony Search (HS) algorithm. Various benchmark functions with different characteristics are used for the evaluation of these algorithms. The experimental results show that the solution quality of the algorithms is not directly related to their robustness. In particular, the algorithm that is highly robust can have a low solution quality, or the algorithm that has a high quality of solution can be quite sensitive to the parameter variations. © 2013 AECE.