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https://hdl.handle.net/20.500.14440/180

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Correlation between the expressions of leptin and its receptors (ObR, sObR) in gastric cancer
(Walter De Gruyter Gmbh, 2016) Cakir, Isil; Kilic, Eser; Coskun, Banu Demet Ozel; Cakir, Nuri; Savaşçıhabeş, Asuman
Objective: The expressions of leptin and its receptor (ObR) have been observed in human gastric cancer (GC) tissue. Leptin can promote the proliferation of GC cells. However, the correlation between leptin and ObR expressions in GC and the role of gastric ObR protein levels in patients with GC is still unclear. This study aimed to evaluate the relationship between leptin, gastric ObR protein and soluble leptin receptor (sObR) levels and whether their possible role of indicator in GC. Methods: Serum leptin, gastric leptin and serum sObR concentrations were determined in 30 male patients with GC and 25 male dyspeptic subjects by enzyme linked immunosorbent assay. We analysed the expression of gastric ObR levels in endoscopically obtained biopsy samples by using Western Blotting method. Results: Compared with controls, patients had lower serum leptin and higher gastric tissue leptin levels. sObR protein concentrations of patients were detected significantly higher, gastric ObR protein expression were lower than subjects in control group. Conclusion: Leptin in gastric cancerous region and sObR in circulation are overexpressed in GC. Their expressions are associated with malignancy. Decreased leptin levels, induces the sObR signal in circulation. This negative feedback regulation is also seen in gastric tissue: increased gastric tissue leptin levels inhibits gastric ObR protein expression. Thus, leptin and ObR may be important indicators in GC.
WEEE estimation and determination of collection points: A case for the Municipality of Cankaya
(Pamukkale Univ, 2018) Kececi, Baris; Dengiz, Orhan; Dengiz, Berna; Sumer, Emre; Kilic, Aybuke; Ceki, Ece; Inan, Bedia
Electrical-electronic waste (WEEE) is generated from electric and electronic devices at the end of their lifecycles. When WEEEs are disposed, burned or disassembled for recycling, they are transformed into products containing hazardous substances and harm the environment and human health. Therefore WEEEs should be collected, transported and processed properly during their recycling operations by municipality authority in order to minimize their damage and maximize their economic benefit. In this paper, a study is carried out for the WEEE management of Cankaya Municipality by the cooperation of Environmental Conservation and Control Department of Cankaya. For this purpose first WEEE with a focus on television, refrigerator, washing machine, oven and vacuum cleaner are estimated based on the electronic device usage behavior of residents in Cankaya. Secondly, the WEEE collection points' location problem is solved considering set covering problem.
Analysis of two stage supply chain coordination under fuzzy demand
(Gazi Univ, Fac Engineering Architecture, 2019) Torun, Hulya; Canbulut, Gülçin
In this study; a two-stage supply chain structure consisting of a supplier and a retailer has been investigated when the demand variable is a fuzzy parameter. Each of the supply chain members has different goals and wants to optimize their performance. Thus coordination between the supply chain members must be confirmed. According to this coordination, supply chains are classified into centralized and decentralized supply chains. For the centralized and decentralized supply chain models, generalized closed-form solutions of optimal order quantity and supply chain members profit functions are obtained using the expected value function and credibility theory when the demand parameter is a fuzzy variable. Then, in addition to the demand fuzziness, when the wholesale price is also considered as a fuzzy variable, supply chain members and supply chain total profits have been obtained for the decentralized supply chain model. Finally, proposed models are analyzed under numerical examples.
Effect of Plan Configuration of Reinforced Concrete Shear Walls on the behavior of Flat Slab Buildings
(Turkish Chamber Civil Engineers, 2020) Bozer, Ali
In this study, the effect of plan configuration of shear walls on the behavior of flat slab building is investigated. For this purpose two seven-story flat slab buildings are designed. In one of the buildings, plan configuration of shear walls is selected symmetrical, whereas in the other building plan configuration is selected to cause torsional irregularity. Seismic performances of both buildings are then investigated by push-over and time-history analyses. It is observed that plan configuration of structural walls has a significant effect on overall ductility of the flat slab buildings.
Genetic Algorithm Application for Permutation Flow Shop Scheduling Problems
(Gazi Univ, 2022) Arık, Oğuzhan Ahmet
In this paper, permutation flow shop scheduling problems (PFSS) are investigated with a genetic algorithm. PFSS problem is a special type of flow shop scheduling problem. In a PFSS problem, there are n jobs to be processed on m machines in series. Each job has to follow the same machine order and each machine must process jobs in the same job order. The most common performance criterion in the literature is the makespan for permutation scheduling problems. In this paper, a genetic algorithm is applied to minimize the makespan. Taillard's instances including 20, 50, and 100 jobs with 5, 10, and 20 machines are used to define the efficiency of the proposed GA by considering lower bounds or optimal makespan values of instances. Furthermore, a sensitivity analysis is made for the parameters of the proposed GA and the sensitivity analysis shows that crossover probability does not affect solution quality and elapsed time. Supplementary to the parameter tuning of the proposed GA, we compare our GA with an existing GA in the literature for PFSS problems and our experimental study reveals that our proposed and well-tuned GA outperforms the existing GA for PFSS problems when the objective is to minimize the makespan.
Discharge Coefficients for Radial-Gated Ogee Spillways by Laboratory Data and by Design of Small Dams
(Turkish Chamber Civil Engineers, 2021) HaktanIr, Tefaruk; Khalaf, Mohammed A.
Using the measured data on 15 laboratory models in USA, six models and one prototype in Turkey, the discharge coefficients (C's) of radial-gated ogee spillways for various gate openings and lake water surface elevations are computed. Comparison of these C's for 22 spillways with the ones given by Figure 9-31 of Design of Small Dams does not show close agreements. It is determined that C depends on both the angle O and the ratio d/H-1, rather than O only where d and H-1 are the gate opening and the upstream head, and statistically significant regression equations are computed individually for each one of 22 cases.
A study on the error probability of digital modulations over ?-?/gamma mixed fading environments
(Pamukkale Univ, 2020) Bilim, Mehmet
In this study, performance analysis of eta-mu/Gamma mixed fading channels of communication systems using noncoherent frequency shift keying and differential phase shift keying digital modulation types is presented. The analysis is based on probability density function and contains mathematically basic functions. For this reason, the proposed analysis is quite simple and understandable from a mathematical point of view. As a result of the analyzes, the closed form average error probability expression is derived. The numerical results obtained by using the derived error expression are compared with the simulation results and the accuracy of the derived expression is shown.
On the Comparative Performance Analysis of Turbo-Coded Non-Ideal Single-Carrier and Multi-Carrier Waveforms over Wideb and Vogler-Hoffmeyer HF Channels
(Spolecnost Pro Radioelektronicke Inzenyrstvi, 2014) Genc, Fatih; Resat, M. Anil; Savaşçıhabeş, Asuman; Ertug, Ozgur
The purpose of this paper is to compare the turbo-coded Orthogonal Frequency Division Multiplexing (OFDM) and turbo-coded Single Carrier Frequency Do-main Equalization (SC-FDE) systems under the effects of Carrier Frequency Offset (CFO), Symbol Timing Offset (STO) and phase noise in wide-band Vogler-Hoffmeyer HF channel model. In mobile communication systems multipath propagation occurs. Therefore channel estimation and equalization is additionally necessary. Furthermore a non-ideal local oscillator generally is misaligned with the operating frequency at the receiver This causes carrier frequency offset. Hence in coded SC-FDE and coded OFDM systems; a very efficient, low complex frequency domain channel estimation and equalization is implemented in this paper Also Cyclic Prefix (CP) based synchronization synchronizes the clock and carrier frequency offset. The simulations show that non-ideal turbo-coded OFDM has better performance with greater diversity than non-ideal turbo-coded SC-FDE system in HF channel.
GOAL PROGRAMMING APPROACH FOR CARRYING PEOPLE WITH PHYSICAL DISABILITIES
(Sveuciliste U Zagrebu, Fakultet Prometnih Znanosti, 2020) Arık, Oğuzhan Ahmet; Köse, Erkan; Canbulut, Gülçin
Most of today's optimization efforts aim to reduce costs, time or the number of resources used. However, optimization efforts should consider other factors as important as these, such as facilitating the lives of the disabled, elderly and pregnant and helping them in their daily lives. In this study, the Nuh Naci Yazgan (NNY) University (Kayseri/Turkey) personnel transport problems were discussed. The NNY University provides a shuttle service to bring employees to school at the start of the work and to leave them at home after work In order to shorten the collection / distribution time and the total distance travelled, the service vehicle does not leave / pick up all employees in front of their homes. Instead, the employees are picked up / dropped at appropriate locations on an intuitively determined route. Since only the time and cost savings are taken into account when determining the service route, some employees have a long walking distance to the service mute. This creates a very important problem, especially for the disabled and pregnant workers. In this study, a new mathematical model is proposed which takes into consideration the physical disadvantages and occupational positions of the employees in order to determine the shortest vehicle mute. The results show that the proposed model can significantly reduce walking distances of physically disabled people without compromising the total distance travelled by the vehicle.
A Quantized Water Cycle Optimization Algorithm for Antenna Array Synthesis by Using Digital Phase Shifters
(Wiley, 2015) Güney, Kerim; Başbuğ, Suad
In this article, a quantized water cycle algorithm (QWCA) is used for the antenna array pattern synthesis with low side-lobe levels (SLLs) and nulls at desired directions by using four-bit digital phase shifters. In addition to the standard features as a metaheuristic algorithm, QWCA has an internal quantization mechanism and a precalculated array factor method. The latter provides an accelerated procedure to QWCA under favour of the digitized values that can be stored in a three-dimensional array. This acceleration is based on the reality that the accessing data in the memory need less time than the usage of the mathematical functions throughout the optimization process. The internal quantization mechanism of QWCA is utilized to achieve digital values matching to the discrete values of the phase shifter instead of the simple rounding up/down routines after optimization. The numerical results showed that QWCA can obtain very good SLLs and null depth levels (NDLs) on the synthesized pattern. Moreover, the results are achieved in remarkably short optimization times. SLL and NDL values obtained by QWCA are also compared with the available literature values. The comparisons reveal that QWCA is able to produce better results than the other compared alternatives. (C) 2014 Wiley Periodicals, Inc
ANFIS models for synthesis of micro-coplanar stripline and asymmetric coplanar stripline with an infinitely wide strip
(Wiley, 2012) Kaya, S.; Güney, Kerim; Yildiz, C.; Turkmen, M.
In this letter, computer-aided design models based on adaptive-network-based fuzzy inference system (ANFIS) for the synthesis of two coplanar stripline structures are presented. These coplanar stripline structures are micro-coplanar stripline and asymmetric coplanar stripline with an infinitely wide strip. Four optimization algorithms, hybrid learning (HL), simulated annealing, least-squares, and genetic, are used to determine optimally the design parameters of the ANFIS models. The results of ANFIS models are compared with the results of quasi-static analysis, synthesis formulas available in the literature, a full-wave electromagnetic simulator IE3D, and experimental works realized in this study. The results of ANFIS models agree with the results of other methods and experimental works. When the performances of ANFIS models are compared with each other, the best results for training and test are obtained from the models trained with HL algorithm. (C) 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 54:460-467, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26530
NEW AND ACCURATE SYNTHESIS FORMULAS FOR ASYMMETRIC COPLANAR WAVEGUIDES
(Wiley, 2011) Kaya, S.; Güney, Kerim
In this letter, new and accurate synthesis formulas to compute the physical dimensions of asymmetric coplanar waveguide (ACPW) are presented. The synthesis formulas are obtained with the use of differential evolution algorithm (DEA), genetic algorithm (GA), particle swarm optimization (PSO), and simulated annealing (SA) algorithm. The synthesis formulas are useful to microwave engineers for accurately calculating the physical dimensions of ACPWs. The results of the synthesis formulas are compared with the quasi-static analysis, a full-wave electromagnetic simulator IE3D, and experimental results obtained in this work. The average percentage errors of the synthesis formulas found by using DEA, GA, PSO, and SA algorithm are calculated to be 0.56, 0.62, 0.87, and 0.88%, respectively, for 2079 ACPW samples having different electrical parameters and physical dimensions, as compared with the results of respective quasi-static analysis. (C) 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1991-1996, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26224
SYNTHESIS OF THINNED LINEAR ANTENNA ARRAYS USING BEES ALGORITHM
(Wiley-Blackwell, 2011) Güney, Kerim; Onay, M.
In this article, we propose a method based on the bees algorithm (BA) to synthesize thinned linear antenna arrays with low sidelobe level. The BA is an optimization algorithm inspired by the behavior of the honey bees to find the optimal way of harvesting food resources around the hive. Several examples with different thinning percentages are given to show the effectiveness of the proposed method. The results of BA are compared with the results of real coded genetic algorithm, ant colony optimization, and iterative Fourier technique. (C) 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:795-799, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25850
Seeker Optimization Algorithm for Interference Suppression of Linear Antenna Arrays by Controlling Position-Only, Phase-Only, and Amplitude-Only
(Wiley, 2011) Güney, Kerim; Basbug, S.
In this article, a stochastic search technique based on seeker optimization algorithm (SOA) is proposed for null steering of linear antenna arrays by controlling the position-only, phase-only, and amplitude-only. The SOA is relatively new optimization algorithm based on the concept of simulating the act of humans' intelligent search with their memory, experience, and uncertainty reasoning. Several numerical examples of Chebyshev pattern with the single, multiple, and broad nulls imposed at the directions of interference are given to illustrate the performance and flexibility of the proposed algorithm. For a comparison, the nulling patterns obtained by simulated annealing (SA) and tabu search (TS) algorithms are also given. Furthermore, the results of SOA are statistically compared with those of SA and TS algorithms. The statistical results of simulations show that SOA is superior to the other compared algorithms. (C) 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE 21:505-518, 2011.
Error analysis of SISO and dual-branch communications with generalized Gaussian noise over FTR fading channels br
(Tubitak Scientific & Technological Research Council Turkey, 2022) Bilim, Mehmet
In this paper, we present error probability analysis for single-input single-output (SISO) and asymmetric dual-branch networks with additive white generalized Gaussian noise (AWGGN) over millimeter-wave (mmW) fluctuating two-ray (FTR) fading channels. Then, we examine the error probability evaluation of a SISO system with imperfect phase errors over mmW FTR fading channels. The probability density function (PDF) approach is employed for the error probability performance evaluation and the novel PDF of the asymmetric dual-branch system over Nakagami-m/mmW FTR fading channels is obtained. Specifically, closed-form expressions are derived for the error probability of the SISO and asymmetric dual-branch networks. The derived error expressions facilitate in effectively evaluating the performance of considered networks in the presence of AWGGN and imperfect phase noise with optimal fading parameters and modulation type. The theoretical derivations are extensively confirmed through exact simulations.
Comparison of the terahertz and optical characteristics of graphene and silicene nanoribbons utilizing first-principles approach
(Natl Inst Optoelectronics, 2016) Yamacli, S.
Optical applications of graphene and related two-dimensional materials are continuously taking interest. In this study, accurate first-principles simulations are utilized for obtaining the terahertz and optical characteristics of realistic graphene and silicene nanoribbons (GNRs and SiNRs). Density functional theory is used for calculating the electron density and then Kubo-Greenwood formalism is applied for the computation and comparison of the complex dielectric functions of equivalent GNR and SiNR samples, which are found to be consistent with the previous results in the literature. Frequency-dependent complex conductivities of the devices under consideration are also obtained. The surface plasmon polariton (SPP) wave propagation properties of GNR and SiNR samples are then interpreted and compared. The frequency-dependent conductivity data are also imported into a full-wave electromagnetic simulation tool and the characteristics of the GNR and SiNR samples are evaluated for use as nanostrip transmission lines. It is found out that GNRs seem to be more advantageous compared to equivalent SiNRs from both SPP wave transmission frequency range and higher conductivity viewpoints.
Antenna Array Synthesis and Failure Correction Using Differential Search Algorithm
(Hindawi Ltd, 2014) Güney, Kerim; Durmus, Ali; Başbuğ, Suad
Differential search (DS) optimization algorithm is proposed for the synthesis of three different types of linear antenna array design examples. The first group of examples is that DS algorithm is used to locate wide nulls on the linear antenna array patterns by controlling amplitude-only. In these examples, sidelobe levels disposed to rise are also suppressed by using DS algorithm in the same optimization process. In the second group of examples, individual nulls are placed with the help of DS algorithm by controlling the amplitude-only, phase-only, and position-only. The last example is a linear antenna array failure correction example. In order to tolerate the element failures, DS is employed to recalculate the amplitude values of the remaining intact elements of the antenna array. The results show that DS is very capable to solve the linear antenna array optimization problems which have different characteristics.
Pattern Nulling of Linear Antenna Arrays Using Backtracking Search Optimization Algorithm
(Hindawi Ltd, 2015) Güney, Kerim; Durmus, Ali
An evolutionary method based on backtracking search optimization algorithm (BSA) is proposed for linear antenna array pattern synthesis with prescribed nulls at interference directions. Pattern nulling is obtained by controlling only the amplitude, position, and phase of the antenna array elements. BSA is an innovative metaheuristic technique based on an iterative process. Various numerical examples of linear array patterns with the prescribed single, multiple, and wide nulls are given to illustrate the performance and flexibility of BSA. The results obtained by BSA are compared with the results of the following seventeen algorithms: particle swarm optimization (PSO), genetic algorithm (GA), modified touring ant colony algorithm (MTACO), quadratic programming method (QPM), bacterial foraging algorithm (BFA), bees algorithm(BA), clonal selection algorithm (CLONALG), plant growth simulation algorithm(PGSA), tabu search algorithm(TSA), memetic algorithm (MA), nondominated sortingGA-2 (NSGA-2), multiobjective differential evolution (MODE), decomposition with differential evolution (MOEA/D-DE), comprehensive learning PSO (CLPSO), harmony search algorithm (HSA), seeker optimization algorithm (SOA), and mean variance mapping optimization (MVMO). The simulation results show that the linear antenna array synthesis using BSA provides low side-lobe levels and deep null levels.
Bees algorithm for interference suppression of linear antenna arrays by controlling the positions of selected elements
(Pleiades Publishing Inc, 2013) Güney, Kerim; Onay, M.
An efficient method based on bees algorithm (BA) for the pattern synthesis of linear antenna arrays with the prescribed nulls is presented. Nulling of the pattern is achieved by controlling only the positions of selected elements. The BA is an optimization algorithm inspired by the natural foraging behavior of honey bees to find the optimal solution. Simulation results for Chebyshev patterns with the imposed single and multiple nulls are given to show the effectiveness of the proposed method.
Backtracking Search Optimization Algorithm for Synthesis of Concentric Circular Antenna Arrays
(Hindawi Ltd, 2014) Güney, Kerim; Durmus, A.; Basbug, S.
A backtracking search optimization algorithm (BSA) is proposed for the synthesis of concentric circular antenna arrays (CCAAs) with the low sidelobe levels at a fixed beamwidth. Several numerical examples of CCAA patterns with the single, multiple, and broad nulls imposed at the directions of interference are also given to illustrate the performance and flexibility of the proposed algorithm. BSA is a relatively new population based evolutionary optimization algorithm. The numerical results show that the design of CCAA using BSA provides good sidelobe levels with a fixed beamwidth. The nulling patterns obtained by BSA are also very good. The quality of results obtained by the BSA is checked by comparing with that of several metaheuristic algorithms in the literature. BSA is also compared with differential search (DS) and bacterial foraging algorithms (BFA) in terms of iterative performances.

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