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Yayın Coupled quintic nonlinear Schrodinger equations in a generalized elastic solid(IOP Publishing Ltd, 2004-10-08) Hacınlıyan, Irma; Erbay, SaadetIn the present study, the nonlinear modulation of transverse waves propagating in a cubically nonlinear dispersive elastic medium is studied using a multiscale expansion of wave solutions. It is found that the propagation of quasimonochromatic transverse waves is described by a pair of coupled nonlinear Schrodinger (CNLS) equations. In the process of deriving the amplitude equations, it is observed that for a specific choice of material constants and wavenumber, the coefficient of nonlinear terms becomes zero, and the CNLS equations are no longer valid for describing the behaviour of transverse waves. In order to balance the nonlinear effects with the dispersive effects, by intensifying the nonlinearity, a new perturbation expansion is used near the critical wavenumber. It is found that the long time behaviour of the transverse waves about the critical wavenumber is given by a pair of coupled quintic nonlinear Schrodinger (CQNLS) equations. In the absence of one of the transverse waves, the CQNLS equations reduce to the single quintic nonlinear Schrodinger (QNLS) equation which has already been obtained in the context of water waves. By using a modified form of the so-called tanh method, some travelling wave solutions of the CQNLS equations are presented.Yayın Çok katmanlı düzlemsel ortam için termoakustik dalga denkleminin çözümü(IEEE, 2017-06-27) Bayıntır, Hazel; Ünalmış Uzun, Banu; İdemen, Mehmet Mithat; Karaman, MustafaBu çalışmada, farklı akustik parametrelere sahip çok katmanlı düzlemsel ortam için tüm katmanlarda kaynak dağılımı olduğu varsayımı altında termoakustik dalga denkleminin analitik olarak düz ve ters çözümü elde edilmiştir. Çok katmanlı düzlemsel ortam için elde edilen analitik çözüm katmanlı düzlemsel green fonksiyonlarına dayanmaktadır. Çok katmanlı düzlemsel modelleme meme, deri ve karın bölgesi görüntülemelerine uygun bir modellemedir. Elde edilen analitik çözüm ile literatürde var olan homojen ortam varsayımına dayanan çözüm her katmanda noktasal kaynak alınarak sayısal olarak karşılaştırılmıştır.Yayın Media portrayals of refugees and their effects on social conflict and social cohesion(T.C. Dışişleri Bakanlığı Stratejik Araştırmalar Merkezi, 2020) Pandır, MüzeyyenMedia portrayals of refugees can produce prejudice toward refugees as well as understanding and acceptance. In that sense, the media have the potential to be part of the problem or part of the solution in issues of conflict and cohesion between host and refugee communities. In this critical time when the future of Syrian refugees in Turkey is being discussed, this article reviews previous research on the media’s representation of refugees, identifies the dominant representational practices and discusses their effects on the inclusion and exclusion of refugees, which may lead to social cohesion or social conflict, respectively. The main body of the article first identifies the negative effects of refugee representations, namely victimization, depoliticization, dehumanization, marginalization, homogenization and deindividualization, and explains in what ways these representations stigmatize refugees as “other” in society and produce prejudice and xenophobia toward them. The article then turns to the representation strategies used to reduce prejudice and motivate understanding in society. Here, empathizing with refugees and taking a rights-based journalism approach are identified among the media’s inclusion practices toward refugees. Overall, specifically focusing on Syrians in Turkey, the paper aims to initiate a discussion on how the media can play a role in assisting the acceptance of refugees, asylum seekers and immigrants in a new country by raising awareness about the media’s representational practices.Yayın Discrimination towards ethnic minorities: how does it relate to majority group members’ outgroup attitudes and support for multiculturalism(Springer, 2017-03) Bağcı Hemşinlioğlu, Sabahat Çiğdem; Çelebi, Elif; Karaköse Çelik, SelinWe examined how ethnic discrimination targeting ethnic minority group members would affect majority group members’ attitudes and multiculturalism towards ethnic minority groups in the context of Turkish–Kurdish interethnic conflict. Study 1 (N = 356) demonstrated that the extent to which majorities (Turkish) believed there was ethnic discrimination towards minorities (Kurdish) in the Turkish society was associated with positive outgroup attitudes and support for multiculturalism through decreased levels of perceived threat from the outgroup. Study 2 (N = 82) showed that Turkish participants who read bogus news reports about the prevalence of ethnic discrimination towards the Kurdish were more positive towards this ethnic group (higher levels of support for multiculturalism, culture maintenance, and intergroup contact) compared to participants in the neutral condition. Furthermore, participants who were presented with lower levels of discrimination (few companies have been discriminatory against the Kurdish) were more positive towards Kurdish people than participants who were presented with higher levels of discrimination (most companies have been discriminatory against the Kurdish). Regardless of the intensity of discrimination, information about the prevalence of ethnic discrimination improved majority members’ attitudes towards ethnic minority groups. Practical and theoretical implications of the studies were discussed.Yayın Technology and politics: have the ICTs turned into a domain for civil-military relations in Turkey?(Routledge Journals, 2016-07-02) Karakaya Polat, Rabia; Kayhan Pusane, ÖzlemThe implications of technology have been widely acknowledged in international relations. Studies ranging from the causes of war and military effectiveness to terrorism and nuclear proliferation have explored how technology shapes international politics. However, the implications of technology in domestic politics have not been scrutinised much. This paper helps fill this vacuum through an analysis of Turkey's civil-military relations. Although civilian control over the Turkish military has improved in the past decade, this process has not been smooth. With a focus on the recent court cases involving the military, the 2007 e-memorandum and the transfer of electronic military intelligence apparatus to the civilian authority, this paper demonstrates how technology has become an important domain for civil-military relations in Turkey.Yayın Imaging of rough surfaces by RTM method(IEEE, 2024) Sefer, Ahmet; Yapar, Ali; Yelkenci, TanjuAn electromagnetic imaging framework is implemented utilizing a single frequency reverse time migration (RTM) technique to accurately reconstruct inaccessible two-dimensional (2D) rough surface profiles from the knowledge of scattered field data. The unknown surface profile, which is expressed as a 1D height function, is either perfectly electric conducting (PEC) or an interface between two penetrable media. For both cases, it is assumed that the surface is illuminated by a number of line sources located in the upper medium. The scattered fields, which should be collected by real measurements in practical applications, are obtained synthetically by solving the associated direct scattering problem through the surface integral equations. RTM is subsequently applied to generate a cross-correlation imaging functional which is evaluated numerically and provides a 2D image of the region of interest. A high correlation is observed by the functional in the regions where the transitions between two media occur. Hence, it results in the acquisition of the unknown surface profile at the sites where the functional attains its highest values. The efficiency of the proposed method is comprehensively tested by numerical examples covering various types of scattering scenarios.Yayın A higher-order model for transverse waves in a generalized elastic solid(Pergamon-Elsevier Science, 2002-11) Hacınlıyan, Avadis Simon; Erbay, SaadetIn the present study, the nonlinear modulation of transverse waves propagating in a generalized elastic solid is studied using a multi-scale expansion of quasi-monochromatic wave solutions. In particular, to include the higher-order nonlinear and dispersive effects in the evolution equations, higher-order perturbation equations are considered, and it is shown that the modulation of two transverse waves is governed by a pair of the coupled higher-order nonlinear Schrodinger (HONLS) equations. In the absence of one of the transverse waves, the coupled HONLS equations reduce to the single HONLS equation that has already been obtained in the context of nonlinear optics. Some special solutions to the coupled HONLS equations are also presented.Yayın Two-dimensional wave packets in an elastic solid with couple stresses(Pergamon-Elsevier Science Ltd, 2004-08) Babaoğlu, Ceni; Erbay, SaadetThe problem of (2+1) (two spatial and one temporal) dimensional wave propagation in a bulk medium composed of an elastic material with couple stresses is considered. The aim is to derive (2+1) non-linear model equations for the description of elastic waves in the far field. Using a multi-scale expansion of quasi-monochromatic wave solutions, it is shown that the modulation of waves is governed by a system of three non-linear evolution equations. These equations involve amplitudes of a short transverse wave, a long transverse wave and a long longitudinal wave, and will be called the "generalized Davey Stewartson equations". Under some restrictions on parameter values, the generalized Davey-Stewartson equations reduce to the Davey-Stewartson and to the non-linear Schrodinger equations. Finally, some special solutions involving sech-tanh-tanh and tanh-tanh-tanh type solitary wave solutions are presented.Yayın WikiLeaks on the Middle East: Obscure diplomacy networks and binding spaces(Routledge Journals, 2014-10-02) Bıçakcı, Ahmet Salih; Rende, Deniz; Rende, Sevinç; Yıldız, Olcay TanerIn this paper, we explore the flow of information regarding strategic Middle Eastern countries in the WikiLeaks 'diplomatic cables' by applying data-mining techniques to construct directed networks. The results show that between 2002 and 2009, US diplomatic communication related to these countries increased although with notable variation in flow patterns. We discuss the value of a visual display of diplomatic communication patterns in understanding the decentralized nature of information gathering on regional foreign policy issues.Yayın Cross-sectional thermoacoustic imaging using multi-layer cylindrical media(IEEE, 2017-11-10) Elmas, Demet; Ünalmış Uzun, Banu; İdemen, Mehmet Mithat; Karaman, MustafaFor cross-sectional two-dimensional thermoacustic imaging of breast and brain, we explored solution of the wave equation using layered tissue model consisting of concentric annular layers on a cylindrical cross-section. To obtain the forward and inverse solutions of the thermoacoustic wave equation, we derived the Green's function involving Bessel and Hankel functions by employing the geometrical and acoustic parameters (densities and velocities) of layered media together with temporal initial condition, radiation conditions and continuity conditions on the layers' boundaries. The image reconstruction based on this approach involves the layer parameters as the apriori information which can be estimated from the acquired thermoacoustic data. To test and compare our layered solution with conventional solution based on homogeneous medium assumption, we performed simulations using numerical test phantoms consisting of sources distributed in the layered structure.
