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Gul E.,Gediz University | Karanci A.N.,Middle East Technical University
Journal of Traumatic Stress | Year: 2017

This study aimed to examine the roles of personality traits, traumatic event types, coping, rumination, and social support in explaining posttraumatic stress symptoms (PTS) and posttraumatic growth (PTG) in a representative community sample of 498 Turkish adults. The results of 2 multiple regression analyses showed that PTS was associated with neuroticism, experiencing events involving intentional/assaultive violence, intrusive and deliberate rumination, and fatalistic coping. In contrast, PTG was related to conscientiousness, openness to experience, injury/shocking and sudden-death type of events, deliberate rumination, problem-solving coping, and perceived social support. When all variables were entered into the equation, almost two thirds of the variability (R2 =.64) in the severity of PTS and more than one third of the variability (R2 =.40) in PTG was explained. The findings can aid in the development of psychosocial support programs for individuals experiencing traumatic events. Copyright © 2017 International Society for Traumatic Stress Studies

Agency: European Commission | Branch: H2020 | Program: MSCA-RISE | Phase: MSCA-RISE-2015 | Award Amount: 1.62M | Year: 2016

According to UNEP, the building sector is estimated to be worth 10% of the global GDP and employs 111 million people. In addition, buildings use about 40% of global energy, 40% of global resources and emit approximately 33% of global GHG emissions. Finally, the fact that people today spend, on average, more than 80% of their time indoors, enhances its social importance. All above indicate the necessity to optimize building design. Architects usually name optimal design the choice among a very limited set of design alternatives, dictated by their experience and intuition. However, modern design of structures requires one to account for a great number of criteria deriving from multiple disciplines, often of conflicting nature. The vast number of alternative choices enhances the possibility of arriving at an optimum with the incorporation of smart, automatic tools in the design process, further guiding designers intuition. The principal aim of the proposed Network is to create and test methodologies for the application of optimization techniques in different design phases of civil structures by developing strong synergies among a multi-disciplinary team of academic experts from Greece, France, Cyprus, Canada, Turkey, Egypt & Jordan and SMEs from France & Greece. A first goal of the project is to exploit the use of shape and topology optimization techniques in computer aided architectural design. Moreover, the Network wants to exchange ideas, propose formulations that correspond to real-life applications and develop solutions for optimal multi-disciplinary architectural design. Of particular interest is the combination of criteria deriving from structural mechanics, eco-design, bioclimatic design and acoustic performance. For each topic, joint workshops, seminars and long-term visits will be organized at the coordinating and partner institutions. The results will be published in scientific journals, professional magazines and presented in international conferences.

Agan Y.,Fatih University | Acar M.F.,Gediz University | Borodin A.,University of Memphis
Journal of Cleaner Production | Year: 2013

Climate change and environmental pollution have become major concerns for a variety of stakeholders. Small and Medium-sized Enterprises (SMEs), which make up 99.8 percent of all businesses in Turkey, are responsible for approximately 70 percent of all industrial pollution. Based on their significance to the economy and their contribution to pollution, SMEs are not getting the research attention they deserve. In this study we explore the drivers (customers, legislation, social responsibility and expected benefits) of SMEs' environmental processes (disposal, reduction, recycling, design, and environmental management systems) and their impact on firm performance. We sample 500 Turkish SMEs using a cross-sectional design. Structural equation modeling (SEM) was utilized to test both the measurement and the structural models. Our research uncovers numerous significant findings. Although many drivers were found to be affecting various processes, the most influential driver was Expected Benefits, with the most significant forces being soft performance expectations like image, reputation, and brand. The strength of drivers is moderated by the sizes of SMEs. SMEs with ISO 14001 certification are likely to perform better on environmental processes, while disposal, design, and EMS are found to be positively impacting performance. Thus government regulations alone are not an effective way to deal with environmental pollution and climate change. SMEs need and want assistance from their business partners and governments. © 2013 Elsevier Ltd. All rights reserved.

Gungor A.,Gediz University | Erbay Z.,Ege University | Hepbasli A.,King Saud University
Applied Energy | Year: 2011

Exergoeconomic analysis of a pilot scale gas engine driven heat pump (GEHP) drying system is performed based on the experimental values using Exergy, Cost, Energy and Mass (EXCEM) analysis method in this study. The performance of the drying system components is discussed, while the important system components are determined to improve the system efficiency. The performance of the drying process is also analyzed for three different medicinal and aromatic plants from the exergoeconomic point of view. A comprehensive parametric study is conducted to investigate the effect of varying dead (reference) state temperatures on exergoeconomic performance parameters for both drying system components and drying process. The correlations between the performance parameters and dead state temperatures are developed. The results have indicated that the dead state temperature affects the performance parameters, particularly the drying process parameters. Rising the dead state temperature leads to an increase in the exergy efficiencies of the drying process and a decrease in the ratio of the thermodynamic loss rate to the capital cost (Ṙex) values in a polynomial form. Ṙex values of the drying process are obtained to be very higher compared to those of the drying system components. © 2011 Elsevier Ltd.

Gungor A.,Gediz University | Erbay Z.,Ege University | Hepbasli A.,Ege University
Applied Energy | Year: 2011

In this study, three medicinal and aromatic plants (Foeniculum vulgare, Malva sylvestris L. and Thymus vulgaris) were dried in a pilot scale gas engine driven heat pump drier, which was designed, constructed and installed in Ege University, Izmir, Turkey. Drying experiments were performed at an air temperature of 45 °C with an air velocity of 1. m/s. In this work, the performance of the drier along with its main components is evaluated using exergy analysis method. The most important component for improving the system efficiency is found to be the gas engine, followed by the exhaust air heat exchanger for the drying system. An exergy loss and flow diagram (the so-called Grassmann diagram) of the whole drying system is also presented to give quantitative information regarding the proportion of the exergy input dissipated in the various system components, while the sustainability index values for the system components are calculated to indicate how sustainability is affected by changing the exergy efficiency of a process. Gas engine, expansion valve and drying ducts account for more than 60% amount of exergy in the system. The exergetic efficiency values are in the range of 77.68-79.21% for the heat pump unit, 39.26-43.24% for the gas engine driven heat pump unit, 81.29-81.56% for the drying chamber and 48.24-51.28% for the overall drying system. © 2010 Elsevier Ltd.

Kusetogullari H.,Gediz University
IEEE Journal on Selected Topics in Signal Processing | Year: 2015

In this paper, dynamic multiple description wavelet based image coding using enhanced particle swarm optimization (EPSO) is proposed for effective multimedia transmission in the dynamically changing network topologies such as mobile ad-hoc networks (MANETs). In wireless networks, multimedia transmission has become a challenging problem because of changing conditions over time such as packet loss rate (PLR), capacity/bandwidth, network and link conditions. The proposed method is used to simultaneously create optimal multiple description coding (MDC) or sub-images based on the dynamically changing capacity/bandwidth of wireless joint/disjoint communication channels/paths. To perform it, PSO is enhanced by adding a position mutation scheme as a generation feature to employ the proposed dynamic cost function to find the optimal solution within in a search space. To create MDs efficiently, three different wavelet transformation methods which are Discrete Wavelet Transform (DWT), Dual Tree-Complex Wavelet Transform (DT-CWT), and Stationary Wavelet Transform (SWT) are investigated. In this manner, a wavelet transform method is first applied to the given input image to create the sub-bands or set of coefficients as a search space, and then EPSO is employed to find optimal results in the search space to generate MDs. The proposed approach produces good quality of descriptions for effective multimedia transmission over dynamically changing and unreliable communication networks, particularly in wireless and ad-hoc networks (MANETs). The results of the proposed method are compared with the state-of-the-art techniques and simulation results demonstrate that using EPSO with DT-CWT provides a significant improvement of optimal and balanced MDC generation with good quality at different bit-rates. © 2014 IEEE.

Haidar Sharif M.,Gediz University | Djeraba C.,Lille University of Science and Technology
Pattern Recognition | Year: 2012

Detection of aberration in video surveillance is an important task for public safety. This paper puts forward a simple but effective framework to detect aberrations in video streams using Entropy, which is estimated on the statistical treatments of the spatiotemporal information of a set of interest points within a region of interest by measuring their degree of randomness of both directions and displacements. Entropy is a measure of the disorder/randomness in video frame. It has been showed that degree of randomness of the directions (circular variance) changes markedly in abnormal state of affairs and does change only direction variation but does not change with displacement variation of the interest point. Degree of randomness of the displacements has been put in for to counterbalance this deficiency. Simple simulations have been exercised to see the characteristics of these crude elements of entropy. Normalized entropy measure provides the knowledge of the state of anomalousness. Experiments have been conducted on various real world video datasets. Both simulation and experimental results report that entropy measures of the frames over time is an outstanding way to characterize anomalies in videos. © 2012 Elsevier Ltd. All rights reserved.

Sharif M.H.,Gediz University
Journal of Circuits, Systems and Computers | Year: 2014

Nowadays high-performance computing (HPC) architectures are designed to resolve assorted sophisticated scientific as well as engineering problems across an ever intensifying number of HPC and professional workloads. Application and computation of key trigonometric functions sine and cosine are in all spheres of our daily life, yet fairly time consuming task in high-performance numerical simulations. In this paper, we have delivered a detailed deliberation of how the micro-architecture of single-core Itanium® and Alpha 21264/21364 processors as well as the manual optimization techniques improve the computing performance of several mathematical functions. On describing the detailed algorithm and its execution pattern on the processor, we have confirmed that the processor micro-architecture side by side manual optimization techniques ameliorate computing performance significantly as compared to not only the standard math library's built-in functions with compiler optimizing options but also Intel® Itanium® library's highly optimized mathematical functions. © 2014 World Scientific Publishing Company.

In this study a recent result on the quadratic stability of switched linear time-invariant systems is applied to the problem of vehicle rollover prevention based on selectively switching between two suspension settings. The suggested switching control scheme reduces the transient magnitude of the load transfer ratio (LTR), which is the rollover detection metric, when and if it is above a certain threshold by switching to a stiffer suspension setting from a default soft one. In this way, the controller activates only when the potential for rollover is significant as measured by the LTR. The switching suspension parameters are chosen in a way that results in closed-loop switched roll dynamic response that is guaranteed to be quadratically stable under arbitrary switching. Moreover, a spectral condition is given that allows checking the stability of the switched roll dynamics that is subject to actuator uncertainty when the upper and lower bounds of the uncertain parameters are known. Numerical simulations demonstrate the efficacy of the suggested switched control approach. © 2011 The Institution of Engineering and Technology.

Cakir O.,Gediz University
Knowledge-Based Systems | Year: 2012

In this paper, we propose a compensatory model for computing with words under discrete linguistic labels and incomplete weight information. This particular model will be useful in the context of multi-attribute decision making problems characterized by discrete linguistic attribute evaluations and partially-known weight information. This group of multi-attribute decision making problems may be modeled as multi-objective programs by using the concept of satisfactory degree, defined for each decision alternative under study. We derive a compensatory program which can be substituted for such multi-objective models. Further, we prove that the optimal solution of this compensatory program is a Pareto solution to the original multi-objective model. To show the working principles of this approach, we illustrate the procedure on two numerical examples from the published literature. We then analyze a concrete example we developed for illustrating the real-life meanings of several model constructs and managerial connotations of the results obtained by using this new approach. © 2011 Elsevier B.V. All rights reserved.

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