WoS İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://gcris.khas.edu.tr/handle/20.500.12469/4465

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Citation Count: 0
Morphotectonic Evolution of Selduk Graben in Development Process of Western Anatolian Grabens
(Tmmob Jeoloji Muhendisleri Odasi, 2023) Yilmaz, Yucel; Gurer, Omer Feyzi; Erbay, Yucel
The Selduk Graben is the name given to the young graben developed in the western tip of the Kuduk Menderes graben. It was a part of the main graben until a strike-slip fault zone cut and displaced it to the southwest during late Quaternary. From this time onward, it has had a semi-independent evolution. In the horsts bordering the graben, metamorphic basement rocks crop out. The fill of the graben consists of alluvium from the Kucuk Menderes River. The Selduk Graben is an asymmetrical graben. The bordering southern horst is more prominent than the northern one, where the normal faults form clear fault steps. Morphologically, the less distinct northern faults may thus be interpreted as antithetic faults, which have developed on the hanging wall of the major listric normal faults of the southern horst. The graben and the bordering horst were cut and displaced by several young strike-slip faults, which have made clear imprints in the morphology, including linear ridges, offset streams, etc. In the development sequence of Western Anatolian grabens, the Selduk Graben is one of the latest ones. The Kuduk Menderes Graben was opened earlier, during the Quaternary. It was located on the horst separating the Buyuk Menderes and Gediz grabens in this period. The elevated horst then collapsed. The Selduk Graben was situated at the western end of the Kuduk Menderes Graben during this period. Later, with the development of NW trending left-lateral strike-slip faults, together with conjugated faults along the coastal region of western Anatolia, the Selcuk Graben was separated from the Kucuk Menderes Graben and has since evolved semi-independently.
Citation Count: 0
Universities between revenue and status: A typology of organizational responses
(Wiley Periodicals, inc, 2023) Topaler, Basak; Kayabasi, Akin
Prior research on behavioral responses to performance has provided limited attention to how different types of performance outcomes interact to affect organizational reactions. Focusing on the pursuit of revenue and status goals by private universities, we offer a typology of organizational responses (i.e., reducing ambitions, compensatory strategies, and complementary use of slack to pursue new opportunities) which are shaped by the set of challenges and capabilities that poor and superior performance in these goal dimensions present. When poor performance in both revenue and status leads to different types of liabilities that together result in a low likelihood of recovery, universities respond by reducing ambitions and diversifying into a lower status market segment, which offers a more promising path to survival. In response to a mixed performance outcome in revenue and status, universities employ compensatory strategies where they make use of the achievement in one goal dimension to repair the damage in the other. Finally, universities expand the scope of activities when they achieve superior performance in both goals, and the resulting slack in revenue and status provides complementary capabilities to pursue new opportunities. These findings extend the early Carnegie proposal and indicate that the portfolio of organizational responses to performance gaps may be broader than previously considered.
Citation Count: 0
On spare parts demand and the installed base concept: A theoretical approach
(Elsevier, 2023) Amniattalab, Ayda; Frenk, J. B. G.; Hekimoglu, Mustafa
Original Equipment Manufacturers (OEMs) aim to design their service supply chain before the introduction of their products to maximize their aftersales business revenues, reduce waste and achieve sustainability. In this study, we develop a stochastic model that unifies the installed base, i.e., the number of products in use, spare parts demand, and the number of discarded products within a single modeling framework based on three product characteristics: sales rate, usage time, and failure rate. Our model describes the installed base and spare part demand evolution over the entire life cycle of a parent product using stochastic point processes. At the same time we propose under very general assumptions on the cdf of the usage time and the mean arrival functions of the sales and failure processes an easy bisection procedure to compute the time at which the expected installed base and rate of the expected demand for spare parts is maximal. Our numerical experiments show that the volume of aftersales services increases in the expected usage time if the products face an increasing failure rate. The same experiments also reveal a 20 percent shift of the time at which the expected installed base is maximal in case the expected usage time is increased threefold. At the same time, we observe a boosting effect of the intensity of the sales process on this point in time.
Citation Count: 1
Homosynaptic plasticity induction causes heterosynaptic changes at the unstimulated neighbors in an induction pattern and location-specific manner
(Frontiers Media Sa, 2023) Argunsah, Ali Ozgur; Israely, Inbal
Dendritic spines are highly dynamic structures whose structural and functional fluctuations depend on multiple factors. Changes in synaptic strength are not limited to synapses directly involved in specific activity patterns. Unstimulated clusters of neighboring spines in and around the site of stimulation can also undergo alterations in strength. Usually, when plasticity is induced at single dendritic spines with glutamate uncaging, neighboring spines do not show any significant structural fluctuations. Here, using two-photon imaging and glutamate uncaging at single dendritic spines of hippocampal pyramidal neurons, we show that structural modifications at unstimulated neighboring spines occur and are a function of the temporal pattern of the plasticity-inducing stimulus. Further, the relative location of the unstimulated neighbors within the local dendritic segment correlates with the extent of heterosynaptic plasticity that is observed. These findings indicate that naturalistic patterns of activity at single spines can shape plasticity at nearby clusters of synapses, and may play a role in priming local inputs for further modifications.
Citation Count: 0
Artisans abroad: British migrant workers in industrialising Europe, 1815-1870
(Routledge Journals, Taylor & Francis Ltd, 2023) Sefer, Akın
[No Abstract Available]
Citation Count: 0
How do you manage? An auto-ethnographic inquiry into contemporary maternal labor
(Emerald Group Publishing Ltd, 2024) Balic, Ilkay
PurposeThis article tackles the intersection of mothering and labor through the author's own experience as a feminist mother/manager from Istanbul, Turkey. It aims to revisit the first years of motherhood, exploring the struggle to invent a peculiar maternal subjectivity in opposition and negotiation with the patriarchal institution of motherhood, the new definition of maternal labor in a highly digital, neoliberal context and the issue of marital fairness in a dual-income heterosexual marriage.Design/methodology/approachThe article presents an autoethnographic, retrospective and introspective inquiry into the first seven years of the author's mothering experience in order to offer an in-depth exploration of the various aspects of contemporary maternal labor.FindingsThe article shows how maternal labor has shifted in nature and expanded in scope in a contemporary non-Western context. It investigates the dissolution of the spatial, temporal and sensorial boundaries between the managerial labor dedicated to the workplace, and to the family. Highlighting the similarities of the two forms of labor, the article manifests the materiality, tangibility and visibility of maternal labor.Research limitations/implicationsFurther intersectional studies shall be beneficial to redefine maternal labor in different contexts.Practical implicationsDeparting and diverting from the terms "invisible labor" and "mental load", the article suggests a shift in terminology to stress the multifaceted medley of managerial tasks mothers undertake today.Originality/valueThe article provides an original take on maternal labor through the first-hand experience of a middle-class, professional mother from Istanbul, Turkey.
Citation Count: 0
Global Ashkin-Teller phase diagrams in two and three dimensions: Multicritical bifurcation versus double tricriticality-endpoint
(Elsevier, 2023) Kecoglu, Ibrahim; Berker, A. Nihat
The global phase diagrams of the Ashkin-Teller model are calculated in d = 2 and 3 by renormalization-group theory that is exact on the hierarchical lattice and approximate on the recently improved Migdal-Kadanoff procedure. Three different ordered phases occur in the dimensionally distinct phase diagrams that reflect three-fold order-parameter permutation symmetry, a closed symmetry line, and a quasi-disorder line. First- and second-order phase boundaries are obtained. In d = 2, second-order phase transitions meeting at a bifurcation point are seen. In d = 3, first- and second-order phase transitions are separated by tricritical and critical endpoints.
Citation Count: 0
Strategic Heterogeneous Customers in a Transportation Station: Information and Pricing
(informs, 2024) Manou, Athanasia; Canbolat, Pelin G.; Karaesmen, Fikri
Problem definition: We consider pricing of services with strategic customers who have heterogeneous delay costs motivated by transportation systems. Customers are strategic decision makers who weigh the reward from the transport service against the waiting cost for the vehicle at a transportation station. Customers arrive at the station according to a Poisson process, and the vehicle visits the station according to a renewal process. We analyze the optimal price and the equilibrium for different levels of information available to customers. Methodology/results: We represent the service system as a stochastic clearing process, heterogeneity in delay cost as a random variable, and heterogeneity in rewards as a positive affine transformation of delay cost. For each information level, we identify the equilibrium behavior of customers and solve the revenue-maximization problem based on this equilibrium. The equilibrium turns out to be unique in each case, and it is of a threshold form in the sense that for each value of the information, it is best to join either for all types of customers, only for those who are sufficiently price sensitive, only for those who are sufficiently delay sensitive, or for none. The optimal fee is also unique in nontrivial cases. This enables us to perform comparisons across different information structures. Managerial implications: The effect of heterogeneity depends highly on model parameters as well as the available information. For a fixed fee, an increase in heterogeneity has a positive overall impact on the customer population, whereas the effect on the revenue can be positive (slow service at a high fee) or negative (fast service at a low fee). Unlike with fixed fee, for the optimal fee, an increase in heterogeneity can have a negative overall effect on customers. Ignoring heterogeneity can lead to a substantial opportunity loss for the system.
Citation Count: 0
Residual LSTM neural network for time dependent consecutive pitch string recognition from spectrograms: a study on Turkish classical music makams
(Springer, 2023) Baykaş, Tunçer; Gursoy, Ahmet Fazil; Baykas, Tuncer; Hekimoglu, Mustafa; Pekcan, Onder
Turkish classical music, characterized by 'makam', specific melodic configurations delineated by sequential pitches and intervals, is rich in cultural significance and poses a considerable challenge in identifying a musical piece's particular makam. This identification complexity remains an issue even for experienced musical experts, emphasizing the need for automated and accurate classification techniques. In response, we introduce a residual LSTM neural network model that classifies makams by leveraging the distinct sequential pitch patterns discerned within various audio segments over spectrogram-based inputs. This model's design uniquely merges the spatial capabilities of two-dimensional convolutional layers with the temporal understanding of one-dimensional convolutional and LSTM mechanisms embedded within a residual framework. Such an integrated approach allows for detailed temporal analysis of shifting frequencies, as revealed in logarithmically scaled spectrograms, and is adept at recognizing consecutive pitch patterns within segments. Employing stratified cross-validation on a comprehensive dataset encompassing 1154 pieces spanning 15 unique makams, we found that our model demonstrated an accuracy of 95.60% for a subset of 9 makams and 89.09% for all 15 makams. Our approach demonstrated consistent precision even when distinguishing makam pairs known for their closely related pitch sequences. To further validate our model's prowess, we conducted benchmark tests against established methodologies found in current literature, providing a comparative assessment of our proposed workflow's abilities.
Citation Count: 1
Driven and non-driven surface chaos in spin-glass sponges
(Pergamon-elsevier Science Ltd, 2023) Pektas, Yigit Ertac; Artun, E. Can; Berker, A. Nihat
A spin-glass system with a smooth or fractal outer surface is studied by renormalization-group theory, in bulk spatial dimension d = 3. Independently varying the surface and bulk random-interaction strengths, phase diagrams are calculated. The smooth surface does not have spin-glass ordering in the absence of bulk spin-glass ordering and always has spin-glass ordering when the bulk is spin-glass ordered. With fractal (d > 2) surfaces, a sponge is obtained and has surface spin-glass ordering also in the absence of bulk spin-glass ordering. The phase diagram has the only-surface-spin-glass ordered phase, the bulk and surface spin-glass ordered phase, and the disordered phase, and a special multicritical point where these three phases meet. All spin-glass phases have distinct chaotic renormalization-group trajectories, with distinct Lyapunov and runaway exponents which we have calculated.
Citation Count: 0
The structure of the Turkish economy
(Routledge Journals, Taylor & Francis Ltd, 2024) Ozden, Oktay
This essay presents a critical analysis of ozgur Orhangazi's Turkiye ekonomisinin yapisi (The structure of the Turkish economy). The book examines the last four decades of the Turkish economy, accounting for its place in the global capitalist system and focusing on the radical effects of the liberalization of capital mobility in 1989. Moreover, the book describes the growth model of the Turkish economy over the last two decades, consisting of three components: high dependency on foreign capital inflow, debt accumulation, and construction-oriented growth. This review finds that the book lacks in its examination of the internal dynamics of capitalism in Turkey, especially concerning the evolution of the two branches of the Turkish bourgeoisie: construction capital, which is the extension of commercial capital; and industrial capital, which has made its mark on the history of capitalism in Turkey. Class struggle inside the bourgeoisie has in fact shaped the last century of economic and political history in Turkey.
Citation Count: 0
The impact of COVID-19 trauma on healthcare workers: Examining the relationship between stress and growth through the lens of memory
(Wiley, 2024) Oner, Sezin; Bilgin, Ezgi; Caglar, Emine Seyma
The COVID-19 pandemic constituted tremendous traumatic stress among the frontline healthcare workers. In the present study, we investigated relationships of two types of rumination, namely brooding and reflection, with traumatic stress and post-traumatic growth and the mediating role of recollective experience in these relationships. A total of 88 healthcare workers (75% female, M-age = 54.91) actively providing service to COVID-19 patients reported two memories of events that impacted them the most at the first peak of the pandemic and rated their recollective experience (i.e., phenomenological characteristics of memories). We used structural equation modelling to test whether recollective experience mediated the link of brooding and reflection with post-trauma reactions of stress and growth. The findings showed that brooding and reflection were associated with higher levels of traumatic stress and post-traumatic growth. Importantly, recollective experience mediated the relationship of rumination with traumatic stress but this differed for the type of rumination. Higher brooding was associated with greater traumatic stress and that relationship was independent of how well the memories were recollected, while for reflection, high reflection was associated with stronger recollective experience, which predicted higher traumatic stress and post-traumatic growth. The present study shows the functional dimensions of reflective rumination and presents novel findings that demonstrates the discrete mnemonic mechanisms underlying the association between brooding, reflection, and post-trauma reactions.
Citation Count: 0
Vertical individualism orientations and mental health stigma: the mediating role of belief in free will
(Springer, 2023) Tatar, Burcu H.; Ozkok, Hazal; Altan-Atalay, Ayse; Turan, Bulent
Even though the stigma related to mental health is widespread, stigma related to suicide and substance use are less researched areas. This study investigates whether belief in free will mediates the association between vertical individualism and stigma against those who use substances or attempt suicide. Turkish adult participants (n = 200, M-age = 29.8, SD = 11.9) completed self-report measures of cultural orientation, belief in free will, substance use stigma, and suicide stigma. Results revealed that individuals' belief in free will mediates the association of vertical individualism with both suicide and substance use stigma. This suggests that free will belief may be one of the ways in which cultural orientations are linked to stigma. These results can contribute to the design of sophisticated stigma reduction interventions that take into account belief in free will and cultural orientation.
Citation Count: 4
Tourist personality, value co-creation, and emotional well-being
(Wiley, 2024) Tosun, Petek; Tosun, Petek
This study aimed to examine value co-creation as a predictor of customer satisfaction and emotional well-being using a comprehensive research model. It investigated the personal (customer extraversion and agreeableness) and situational (customer-employee rapport) variables that influence value co-creation (customer participation and citizenship behaviors) and, consequently, lead to customer satisfaction and emotional well-being. The tourism sector was selected for the study because value co-creation, satisfaction, and emotional well-being are crucial for hotel managers and academic researchers in the dynamic and competitive service environment. Around 400 tourists in Turkey participated in the field research. Data analysis with partial least squares structural equation modeling showed that extraversion and agreeableness positively influenced customer-employee rapport and value co-creation; agreeable and extroverted customers are more likely to positively interact with the service staff and engage in value co-creation. Customer-employee rapport positively affects value co-creation, customer satisfaction, and emotional well-being. Value co-creation has a significant positive impact on customer satisfaction and emotional well-being. The results contribute to the literature by testing an original model illustrating customers' role in value co-creation. Customer personalities shape value co-creation in dyadic exchange relationships. Their personalities, behaviors, and interactions during the service process shape their satisfaction and emotional well-being. This study contributes to the social exchange theory and service-dominant logic perspectives by providing empirical evidence regarding the significant direct impact of value co-creation on tourists' emotional well-being.
Citation Count: 0
Cryptocurrencies as a means of payment in online shopping
(Emerald Group Publishing Ltd, 2024) Tosun, Petek; Tosun, Petek; Gurce, Merve Yanar
PurposeCryptocurrencies are becoming increasingly attractive as alternatives to traditional currencies. Although many retailers accept cryptocurrencies as a means of payment in online shopping, consumers' cryptocurrency adoption intention in online shopping (CCAI) is still low. This study aims to investigate the influence of attitudes, subjective norms, consumer trust, financial literacy and fear of missing out (FOMO) on CCAI.Design/methodology/approachA quantitative research approach was followed using a consumer survey. Hypothesized relationships were tested through regression and mediation analyses.FindingsThe results revealed that consumers could accept cryptocurrencies as a means of payment in online shopping. Attitudes, subjective norms, consumer trust and financial literacy directly and positively influence CCAI, while they indirectly affect CCAI through the mediating impact of FOMO.Practical implicationsMarketing managers should improve consumers' knowledge about cryptocurrencies and trust in online shopping to increase CCAI. Social media marketing can be appropriate, while the advertising content can address keeping up with others and staying connected.Originality/valueThis study addresses a critical gap in the literature by empirically examining the antecedents of CCAI within an original conceptual model based on the theoretical framework provided by the theory of planned behavior. Attitudes, subjective norms, trust and financial literacy influence CCAI, where FOMO plays a significant role as a mediator.
Citation Count: 0
Aesthetic Approach for Critical Sociology of Contemporary Communication Technology
(Sage Publications inc, 2024) Arda, Balca
Critical theory has already marked that technology often threatens civil liberties, personal autonomy, and rights. Heidegger, later Marcuse, emphasized how technology is not value-free in its own revealing power of the surrounding environment, external and inner nature. Throughout this paper, I explore how the aesthetic approach engages with critical theory and contributes to the sociology of media and communication. For this, I will theoretically survey the terms of sociality under the forces of immediate communication, ubiquitous surveillance, and the compression of time and space that Baudrillard and Virilio once problematized through the lens of critical technology theory to adapt it to media and communication studies. I contend that techno-aesthetics that converge with Ranciere's dissensus can provide practical suggestions on an updated vocation of critical sociology. This article discusses the potential of aesthetic and social criticism of media for democratizing technology that Feenberg inserted. It is urgent to acknowledge the changing spatio-temporal aesthetic regimes that affect the societal imagination and limits of sociality and action to determine the next steps for achieving a commons-based society.
Citation Count: 0
Impact of the COVID-19 Market Turmoil on Investor Behavior: A Panel VAR Study of Bank Stocks in Borsa Istanbul
(Mdpi, 2024) Ersan, Oğuz; Ersan, Oguz
Assuming that investors can be foreign or local, do high-frequency trading (HFT) or not, and submit orders through a bank-owned or non-bank-owned broker, we associated trades to various investors. Then, building a panel vector autoregressive model, we analyzed the dynamic relation of these investors with returns and among each other before and during the COVID-19 market crash. Results show that investor groups have influence on each other. Their net purchases also interact with returns. Moreover, during the turmoil caused by the pandemic, except foreign investors not involved in HFT, the response of any investor group (retail/institutional, domestic investors doing HFT and those not doing HFT, and foreign investors doing HFT) significantly altered. This shows that the interrelation among investor groups is dynamic and sensitive to market conditions.
Citation Count: 0
KERMA, projected range, mass stopping power and gamma-ray shielding properties of antimony and tellurium reinforced iron phosphate glasses
(Pergamon-elsevier Science Ltd, 2024) Alan, Hatice Yilmaz; Yilmaz, Ayberk; Susam, Lidya Amon; Ozturk, Gizem; Kilic, Gokhan; Ilik, Erkan; Tekin, H. O.
In this study, the radiation shielding effectiveness of iron phosphate glass (Fe 2 O 3 - P 2 O 5 ) doped with antimony (Sb) and tellurium (Te) is assessed in detail using advanced computational methods. The projected range, mass stopping power, and KERMA (Kinetic Energy Released per unit MAss) for fourteen different iron phosphate glass samples are calculated through the PAGEX and SRIM software. Mass attenuation coefficients, linear attenuation coefficients, mean free path, half value layers, tenth value layers, and effective atomic number are determined in 0.015 - 15 MeV energy range. The research reveals that doping iron phosphate glass with Sb 2 O 3 significantly enhances its shielding capabilities when compared to the inclusion of TeO 2 . Another important aspect is, the IPGSb50 sample exhibited the highest KERMA values, indicating its exceptional capacity for energy absorption from ionizing radiation. Additionally, the IPGSb50 sample exhibited the lowest projected range for alpha particles, also this sample demonstrated a similar prowess in limiting the penetration of proton particles. Our findings indicate that the incorporation of Sb 2 O 3 and TeO 2 into iron phosphate glass matrices results in a noticeable improvement in gamma radiation shielding effectiveness. These doped glasses could serve as potent alternatives to traditional lead -based shielding materials, offering a safer and potentially more effective barrier against a variety of radiation types.
Citation Count: 0
A new cloud-based method for composition of healthcare services using deep reinforcement learning and Kalman filtering
(Pergamon-elsevier Science Ltd, 2024) Zhong, Chongzhou; Darbandi, Mehdi; Nassr, Mohammad; Latifian, Ahmad; Hosseinzadeh, Mehdi; Navimipour, Nima Jafari
Healthcare has significantly contributed to the well-being of individuals around the globe; nevertheless, further benefits could be derived from a more streamlined healthcare system without incurring additional costs. Recently, the main attributes of cloud computing, such as on-demand service, high scalability, and virtualization, have brought many benefits across many areas, especially in medical services. It is considered an important element in healthcare services, enhancing the performance and efficacy of the services. The current state of the healthcare industry requires the supply of healthcare products and services, increasing its viability for everyone involved. Developing new approaches for discovering and selecting healthcare services in the cloud has become more critical due to the rising popularity of these kinds of services. As a result of the diverse array of healthcare services, service composition enables the execution of intricate operations by integrating multiple services' functionalities into a single procedure. However, many methods in this field encounter several issues, such as high energy consumption, cost, and response time. This article introduces a novel layered method for selecting and evaluating healthcare services to find optimal service selection and composition solutions based on Deep Reinforcement Learning (Deep RL), Kalman filtering, and repeated training, addressing the aforementioned issues. The results revealed that the proposed method has achieved acceptable results in terms of availability, reliability, energy consumption, and response time when compared to other methods.
Citation Count: 0
What is Quantum in probabilistic explanations of the sure-thing principle violation?
(Elsevier Sci Ltd, 2024) Pusuluk, Onur; Pusuluk, Onur
The Prisoner's Dilemma game (PDG) is one of the simple test -beds for the probabilistic nature of the human decision -making process. Behavioral experiments have been conducted on this game for decades and show a violation of the so-called sure -thing principle , a key principle in the rational theory of decision. Quantum probabilistic models can explain this violation as a second -order interference effect, which cannot be accounted for by classical probability theory. Here, we adopt the framework of generalized probabilistic theories and approach this explanation from the viewpoint of quantum information theory to identify the source of the interference. In particular, we reformulate one of the existing quantum probabilistic models using density matrix formalism and consider different amounts of classical and quantum uncertainties for one player's prediction about another player's action in PDG. This enables us to demonstrate that what makes possible the explanation of the violation is the presence of quantum coherence in the player's initial prediction and its conversion to probabilities during the dynamics. Moreover, we discuss the role of other quantum informationtheoretical quantities, such as quantum entanglement, in the decision -making process. Finally, we propose a three -choice extension of the PDG to compare the predictive powers of quantum probability theory and a more general probabilistic theory that includes it as a particular case and exhibits third -order interference.

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