Wos Kapalı Erişimli Yayınlar
Permanent URI for this collectionhttps://hdl.handle.net/11727/10753
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Item Could Plasma Asymmetric Dimethylarginine Level Be A Novel Predictor Beyond The Classic Predictors of Stent Restenosis?(2014) Bal, Ugur Abbas; Yildirir, Aylin; Aydinalp, Alp; Kaynar, Gamze; Kanyilmaz, Suleyman; Murat, Koza; Muderrisoglu, Ibrahim Haldun; https://orcid.org/0000-0002-9446-2518; https://orcid.org/0000-0001-8750-5287; https://orcid.org/0000-0002-3761-8782; 25233494; AAK-4322-2021; A-4947-2018; AAD-5841-2021Objective: The aim of this study was to investigate the factors associated with coronary stent restenosis and if there is an association between plasma asymmetric dimethylarginine (ADMA) levels and stent restenosis. Methods: Ninety-one patients, who had a history of coronary bare metal stent implantation due to any cause in the last one year period, were admitted to this observational cross-sectional study. Coronary angiography was performed to all patients and quantitative angiography was used to determine the presence of stent restenosis. Laboratory parameters and angiographic features that contribute to stent restenosis were evaluated. Plasma ADMA levels were measured by using high performance liquid chromatography. Logistic regression analysis was used to determine the independent factors of stent restenosis. Results: Angiographic restenosis was found in 35 patients (38.5%). Stent diameter (p=0.038) and left ventricular ejection fraction (p=0.023) were lower and stent implantation history due to acute coronary syndrome (p=0.029), plasma ADMA level (5.0 +/- 1.8x10(-4) mmol/L vs. 3.9 +/- 1.0x10(-4) mmol/L, p=0.001), C-reactive protein concentration (p=0.016), white blood cell count (p=0.044) and stent length (p=0.005) were higher in patients with restenosis. Plasma ADMA level (beta=0.536; OR: 1.710; CI: 1.022-2.861; p=0.041), C-reactive protein concentration (beta=0.062; OR: 1.064; CI: 1.003-1.129; p=0.041), stent diameter (beta=-3.047; OR: 0.048; CI: 0.007-0.313; p=0.002) and length (beta=0.165; OR: 1.179; CI: 1.036-1.343; p=0.013) were found to be the independent predictors of stent restenosis in logistic regression analysis. Conclusion: We conclude that plasma ADMA levels may be used as a novel marker for stent restenosis beyond the classic stent restenosis markers.Item Solving A Nonhomogeneous Linear System of Interval Differential Equations(2018) Gasilov, Nizami A.; Amrahov, Sahin Emrah; AAN-9386-2020In most application problems, the exact values of the input parameters are unknown, but the intervals in which these values lie can be determined. In such problems, the dynamics of the system are described by an interval-valued differential equation. In this study, we present a new approach to nonhomogeneous systems of interval differential equations. We consider linear differential equations with real coefficients, but with interval initial values and forcing terms that are sets of real functions. For each forcing term, we assume these real functions to be linearly distributed between two given real functions. We seek solutions not as a vector of interval-valued functions, as usual, but as a set of real vector functions. We develop a method to find the solution and establish an existence and uniqueness theorem. We explain our approach and solution method through an illustrative example. Further, we demonstrate the advantages of the proposed approach over the differential inclusion approach and the generalized differentiability approach.Item A Self-tuning Heuristic for the Design of Communication Networks(2015) Dengiz, Berna; Alabas-Uslu, CigdemThis paper addresses the design of communication networks that has a large application area. The problem is to design a minimum cost network subject to a given reliability level. Complexity of the problem is twofold: (1) finding a minimum-cost network topology that every pair of nodes can communicate with each other and (2) computing overall reliability to provide the reliability constraint. Over the last two decades, metahemistic algorithms have been widely applied to solve this problem due to its NP-hardness. In this study, a self-tuning heuristic (STH), which is a new approach free from parameter tuning, is applied to the design of communication networks. Extensive computational results confirm that STH generates superior solutions to the problem in comparison to some well-known local search metaheuristics, and also more sophisticated metaheuristics proposed in the literature. The practical advantage of STH lies in both its effectiveness and simplicity in application to the design problem.Item A Self-adaptive Local Search Algorithm for the Classical Vehicle Routing Problem(2011) Alabas-Uslu, Cigdem; Dengiz, BernaThe purpose of this study is introduction of a local search heuristic free from parameter tuning to solve classical vehicle routing problem (VRP). The VRP can be described as the problem of designing optimal delivery of routes from one depot to a number of customers under the limitations of side constraints to minimize the total traveling cost. The importance of this problem comes from practical as well as theoretical point of view. The proposed heuristic, self-adaptive local search (SALS), has one generic parameter which is learnt throughout the search process. Computational experiments confirm that SALS gives high qualified solutions to the VRP and ensures at least an average performance, in terms of efficiency and effectiveness, on the problem when compared with the recent and sophisticated approaches from the literature. The most important advantage of the proposed heuristic is the application convenience for the end-users. SALS also is flexible that can be easily applied to variations of VRP. (C) 2011 Elsevier Ltd. All rights reserved.Item Understanding the Effect of Assignment of Importance Scores of Evaluation Criteria Randomly in the Application of DOE-TOPSIS in Decision Making(2019) Ic, Yusuf Tansel; Yurdakul, Mustafa; 0000-0001-9274-7467; AGE-3003-2022In conventional applications of hybrid DoE-TOPSIS technique in decision making problems, full factorial design layouts are generally used because of their ability to measure the effects of all possible combinations for evaluation factors. In a typical application, for a design layout, a number of replications are generated by assigning different sets of relative importance scores for evaluation factors. A TOPSIS score is then obtained for each experiment and replication pair. Regression analysis is finally applied to obtain a relationship with inputs (values of evaluation factors) and outputs (alternatives' TOPSIS meta-model scores). The key in conventional application of hybrid DoE-TOPSIS technique is generation of relative importance scores. Each set of scores can be assigned by a decision maker or generated randomly. This paper aims to determine whether using either of the two methods in determination of relative importance scores makes any difference in the ranking orders of alternatives.Item Gold nanocomposites for biomedical applications(2019) Akturk, Omer; Erdemli, Ozge; Tunali, Beste Cagdas; 0000-0001-8606-8863; AAF-4496-2019; AAG-3927-2019Item A METHOD SUGGESTION TO MEASURE THE EFFECTIVENESS OF INFORMED CONSENT DURING TREATMENT PROCESS A Study on University Students(2019) Buken, Erhan; Yasar, Zehtiye Fusun; Zengin, Hatice Yagmur; Buken, Bora; 0000-0002-4779-0623; 0000-0002-9855-2449; AAL-6847-2021; ABA-3224-2021It is difficult and subjective to evaluate how much of the treatment information given has been understood by the patient during the informing process. Various court decisions show that courts expect a hundred percent success in the informing process. This research was conducted to observe the effectiveness of written and verbal information given under ideal conditions. A coronary angiography consent form was standardized to measure readability and understandability. Two different labyrinth tests were performed from the text. Tests were performed on the Baskent University students in Turkey. The labyrinth test's subjects responded to the test after verbal information, had an absolute rate of 32.5% while the labyrinth test's subjects, responded to prior verbal information had an absolute success rate of 15%. 87.7% of those who achieved absolute success, in the second labyrinth test, also received verbal information. In the verbally informed group, those who achieved absolute success in the first test were 8.5%, while this rate increased to 28.5% after verbal information. There was no difference between the groups, in terms of the number of correct answers and response time, in the first test. Significant differences between the groups' tests arose in the test administered after being informed. This paper argues that the difference of total correct answers between the groups, in the post-test, stems from the effects of verbal informing. This study observed that verbally informing is more effective than written informing. It concludes that the success of the informing process can be measured by developing standardized methods, though it is unlikely to achieve 100% success.Item Is ingroup favoritism contingent on the expectation of reciprocity from ingroup members?: The case of reputation manipulation(2019) Kologlugil, Serhat; Tekes, BurcuWe use a game of cooperation with minimal groups to test whether ingroup favoritism can be explained by the expectation of reciprocity from ingroup members. To do this, we first manipulate participants' level expected cooperation from ingroup and outgroup partners by letting them play the game with different partners having different (high or low) cooperative reputations. We then analyze how these expectations affect ingroup bias in the game across different reputation conditions. We find that even if subjects expect the same level of cooperation from ingroup and outgroup partners withhigh reputation, they still cooperate more with the former than the latter. This contradicts the reciprocity hypothesis in the literature which explains intergroup discrimination solely in reference to differential reciprocal expectations. But, against ingroup and outgroup partners withlow cooperative reputation, subjects' level of cooperation almost exactly parallel their reciprocal expectations. This result is in line with the reciprocity hypothesis. We explain these findings by arguing that both reciprocal expectations and social identity play their parts in the emergence of ingroup favoritism, but that their relative strengths may depend on the interaction with other contextual factors. We also argue in favor of further experimental research as to how reciprocity and social identity interact with such third factors as partner's reputation in different games of social exchange.Item There is Always Light at the End of the Tunnel: Emotions of a Turkish School Leader in a Temporary Education Center for Syrian Children(2019) Orucu, DenizThis chapter depicts the case of a leading school principal in a large suburban Temporary Education Center for Syrian students in Turkey through exploring his emotions and the ways in which he de/regulates them, while performing his professional duties. A single-case study technique was employed within the qualitative realm. Data were attained by interviews, narratives and observations at the school. Drawing on the cultural view on emotions, this authentic school leader's emotions and emotional regulation (ER) style were analysed as he poses a critical case in refugee education, an unfamiliar phenomenon for Turkish schools. The findings revealed the impact of the cumbersome reality of culture on the emotions, which is a blend of religion, faith, traditions and consequent values in this case and the strategies selected for emotion regulation. His ER techniques are an outcome of his patriotic values, deep belief in justice and humanity, formed by his faith and Anatolian culture he adopted. The data show that the Western perspectives of emotion literature may not necessarily be valid in a case where locally embedded needs and dynamics are interwoven. His paternalistic care and relevant display of emotions create a form of trust and confidence in the other members of the fragile school community and parents, which is significant in demonstrating the impact of local needs.Item Computational intelligence models for PIV based particle (cuttings) direction and velocity estimation in multi-phase flows(2019) Tombul, Hatice; Ozbayoglu, A. Murat; Ozbayoglu, M. EvrenIn multi-phase flow, the gas phase, the liquid phase and the particles (cuttings) within the liquid have different flow behaviors. Particle velocity and particle direction are two of the important aspects for determining the drilling particle behavior in multi-phase flows. There exists a lack of information about particle behavior inside a drilling annular wellbore. This paper presents an approach for particle velocity and direction estimation based on data obtained through Particle Image Velocimetry (PIV) techniques fed into computational intelligence models, in particular Artificial Neural Networks (ANNs) and Support Vector Machines (SVM). In this work, feed forward neural networks, support vector machines, support vector regression, linear regression and nonlinear regression models are used for estimating both particle velocity and particle direction. The proposed system was trained and tested using the experimental data obtained from an eccentric pipe configuration. Experiments have been conducted at the Cuttings Transport and Multi-phase Flow Laboratory of the Department of Petroleum and Natural Gas Engineering at Middle East Technical University. A high speed digital camera was used for recording the flow at the laboratory. Collected experimental data set consisted of 1080 and 1235 data points for 15 degrees inclined wellbores, 1087 and 1552 data points for 30 degrees inclined wellbores and 885 and 1119 data points for horizontal (0 degrees), wellbores respectively to use in estimation and classification problems. Results obtained from computational intelligence models are compared with each other through some performance metrics. The results showed that the SVM model was the best estimator for direction estimation, meanwhile the SVR model was the best estimator for velocity estimation. The direction and speed of the particles were estimated with a reasonable accuracy; hence the proposed model can be used in eccentric pipes in the field.