Browsing by Author "Sahin, Ahmet"

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A Comparative Study on Urban and Rural Households Preferences of Fresh Mutton Meat Consumption (A Case Study in Eastern Region of Turkey-Heckman Model)
(Emerald Group Publishing Ltd, 2014) Sahin, Ahmet; Yildirim, Ibrahim; Deniz, Ahmet
Purpose - The purpose of this paper is to perform a comparative assessment of the urban and rural households' preferences of fresh mutton meat consumption in Hakkari, Turkey. Design/methodology/approach - The sample size consisted of 95 rural and 95 urban households. The data were collected from November 2007 until May 2008 intermittently. Probity and Heckman Models were used in the study. Findings - Price elasticity of mutton meat demand was calculated as -0.242, which reveals the mutton meat is a compulsory good in the research area. Income elasticity of mutton meat was found as 0.39, which shows relatively satisfactory amount of mutton meat is consumed. However, there existed great differences in terms of mutton meat consumption per capita among the income groups. Originality/value - The findings in the study may contribute to the mutton meat producers and marketers in the region when planning their production and marketing strategies.
Developing Strategies for Chicken Meat Producers Against Market Prices Risks in Turkey (Game Theory Approach)
(Emerald Group Publishing Limited, 2009) Sahin, Ahmet; Yildirim, Ibrahim; Miran, Buelent
Purpose - The major aim of study was to determine the chicken meat producer's optimal selling times. Design/methodology/approach - The method used for this purpose was Wald, Benefit and Regret criterions of Game Theory. The transformed Wald, Benefit and Regret linear programming models were solved to find the optimal solution. The data consisted of monthly chicken meat prices received by producers between 2000-2007, which were obtained from the Poultry Meat Producers and Breeders Association. Findings - The optimal solutions of Wald and Benefit criteria showed that June was the best selling month for chicken meat producers in Turkey. August was found to be the optimal selling month according to the Minimum regret criterion. In light of the Maximum criterion it was concluded that the producers would be at highest regret positions with 98.28 percent in event of selling in November. Originality/value - The results found in this study could be an indicator for individual chicken producers for a more competitive bargaining power when they make a contract with chicken meat production and marketing firms.
Fattening Costs of Beef Breeds Reared Under Controlled Conditions and the Determination of Optimum Fattening Period
(Tubitak Scientific & Technological Research Council Turkey, 2009) Sahin, Ahmet; Miran, Buelent; Yildirim, Ibrahim; Onenc, Alper; Alcicek, Ahmet
The primary purpose of this study was to calculate the fattening costs of different cattle breeds reared under controlled conditions and to determine the optimal fattening period that will maximize the net profit. The data were from 21 bullocks consisting of 7 Holstein, 7 Piedmont x Holstein, and 7 Limousin x Holstein cross-breed cattle reared and fattened in the closed tie-stall experiment barns of the Aegean Agricultural Research Institute, Turkey. The data used for the analysis were from the year 1999, but were updated for 2007. The fattening period lasted 280 days, after a rearing period of 195 days. The average live weight, costs of 1 kg live weight, yield ratio, and net profit per animal at the end of fattening period were 510.86 kg, YTL 3.65, 57.36%, and YTL 462.33, respectively. The Limousin breed yielded the highest net profit. The optimal fattening period was 5 months. Net profit increased by 21.67%, while the costs of 1 kg live weight decreased by 13.97% at optimal fattening relative to the fattening period in the application. Live weight, yield ratio, meat price, gross production value, production costs, and net profit per animal differed significantly among the Holstein, Piedmont, and Limousin breeds. The results indicated clearly that the optimal fattening period (5 months) yielded much more net profit in comparison with the fattening period in the application. It appears possible to arrange different plans for different cattle breeds.
Investigation of the Impact of Vaginal Marker Utilization on Radiotherapy Treatment Plans Created with Various Planning Systems in Endometrial Cancer Patients
(Wolters Kluwer Medknow Publications, 2025) Demir, Hikmettin; Yavuz, Berrin Benli; Sahin, Ahmet
Purpose:Our aim is to compare treatment plans with vaginal markers used in radiotherapy target volume definition with those without markers, which we have not encountered in our literature searches, and to investigate whether patients with endometrial cancer (EC) can undergo treatment with a single simulation tomography.Materials and Methods:A total of twenty patients with EC were randomly selected. All patients underwent a computerized tomography in the supine position. During the scan, the arms were folded over the chest, and the feet were fixed with a foot immobilizer. Tomography scans were performed with a vaginal marker. A total of four treatment plans were made by a medical physicist using tomography images with both vaginal markers (CT Set 1) and 0 Hounsfield units assigned to the vaginal marker (CT Set 2) under the same conditions.Results:The mean doses of maximum and mean of planning target volume (PTV) and critical organs were derived from the data obtained from the treatment plans created using CT Set 1 and CT Set 2. No significant differences were observed regarding PTV or critical organs when comparing the plans of CT Set 1 and CT Set 2 in both Treatment Planning Systems.Conclusions:Dosimetric comparison of plans with and without vaginal markers, no difference was found in terms of dosimetric parameters. Therefore, we suggested that a clinical decision can be made to plan with vaginal markers, thus ensuring that the patient does not receive an unnecessary second tomography dose.
Profit Maximization of Cattle Fattening Breed Based on Characteristics of Producers: an Application of Game Theory
(Medwell online, 2008) Sahin, Ahmet; Miran, Buelent; Yildirim, Ibrahim; Onenc, Alper
The major purpose of this study was to determine the cattle fattening breed, which maximizes the net profit for the producers under risks and uncertainties based on different characteristics of producers. The monthly data of 21 bullocks consisted of 7 Holstein, 7 PiedmonxHolstain and 7 LimuzinxHolstein cross-breed cattle fattened in closed tie-stall experiment barns of Aegean Agricultural Research Institute, Izmir, Turkey were used in the study. The games were constructed based on the net profit per cattle obtained in the 5th month of fattening where the highest total profit was obtained. Maximaks, Wald, Regret, Hurwicz, Utility and Laplace Criterions of Game Theory were used. The Maximaks, Regret, Hurwics and Laplace Criterions showed that the best breed was Limuzin for the producers in terms of net profit per cattle. According, the results of Wald and Utility Criterions of Game Theory, the optimal breed was Piedmont. Holstein breed was not compatible with any criterions used in this study. Since, the highest net profit per cattle ($ 588.33) is obtained from Limuzin breed by applying Maximaks Criterion, we strongly recommend this breed for optimistic producers. However, the characteristics of producers will determine which criterion to apply to choose the best breed.