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Today, meeting the ever-increasing energy demand with fossil fuels increases greenhouse gas emissions. This rise is dragging our world towards a global climate crisis. Therefore, it becomes imperative for countries to switch to renewable and green energy before global warming reaches the point of no return. Solar and hydrogen energy, which are the leading renewable sources, are increasing in popularity with the studies and investments made in recent years. This study examined a hybrid system combining solar and hydrogen energy by creating mathematical models of a 200 W photovoltaic (PV) panel and a 100 W Proton Exchange Membrane (PEM) fuel cell in MATLAB/Simulink. Combining the submodels obtained step by step using the definition equations of the PV panel and PEM fuel cell, the polarization and power graph of the fuel cell was obtained. The models are explained in detail and reproducibly, and all model parameters are shared. DC-DC boost converter models were developed for both sources, and the panel and fuel cell were connected in parallel to feed a typical resistive load. 3.795 A ve 6.205 A were obtained from the PEM fuel cell and PV panel, respectively, providing 300 W power. [ABSTRACT FROM AUTHOR]

Copyright of Western Anatolia Journal of Educational Sciences (WAJES) / Batı Anadolu Eğitim Bilimleri Dergisi is the property of Dokuz Eylul University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Hacettepe University Journal of Economics & Administrative Sciences / Hacettepe Üniversitesi Iktisadi ve Idari Bilimler Fakültesi Dergisi is the property of Hacettepe University, Faculty of Economic & Administrative Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bu çalışmada PV modüller için tek-diyot eşdeğer devre parametrelerinin belirlenmesine ilişkin analitik bir model önerilmektedir. Çalışmada ilk olarak literatürde mevcut çok sayıda PV modüller için kısa devre akımı (Isc) ve foton akımı (Ipv) değerleri kullanılarak eğri uydurma yöntemi ile akımlar arasında bir matematiksel bağıntı oluşturulmuştur. Daha sonra, akımlar arasında geliştirilen bu bağıntı eşdeğer devre denklemlerinde kullanılarak 3 bilinmeyenli (Rp, Rs ve a) denklem sisteminden oluşan analitik model geliştirilmiştir. Yapılan analizler, model ile elde edilen eşdeğer devre parametrelerinin ve sonucunda oluşturulan I-V ve P-V karakteristiklerinin deneysel veriler ile çok büyük oranda örtüştüğünü göstermektedir. Bu nedenle hesaplanan ve gerçek veriler arasındaki Hatanın Ortalama Karekökü (RMSE) ve Belirleme Katsayısı (R2) değerleri ihmal edilebilir düzeyde bulunmuştur. Ayrıca modelin diğer yöntemlere göre parametre kestiriminde kullanım kolaylığı, deneysel verilere daha az ihtiyaç duyma ve tüm parametreleri belirleyebilme gibi avantajları olduğunu söylemek mümkündür.

Copyright of SDU Journal of Engineering Sciences & Design / Mühendislik Bilimleri ve Tasarım Dergisi is the property of Journal of Engineering Sciences & Design and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Recycling, remanufacturing and repair processes increase the profitability of companies by providing less energy use and less waste generation, and have a positive effect on the total cost of the supply chain. In the present study, an integrated inventory model, which considers economic and environmental objectives together, was developed for a two-level supply chain system consisting of a single manufacturer and a single retailer located in different countries. The problem is the simultaneous calculation of the manufacturer's number of shipments and the buyer's shipment sizes, that is, the parameters of the integrated production-inventory policy, to minimize the total cost of the system. Each batch the retailer received contains both good quality products and defective products. Some of the defective products are scrapped and sent back to the manufacturer to enter the recycling/remanufacturing process, while the other part is added to the inventory after being repaired at a local company. The carbon emission costs of transporting products from manufacturer to retailer and defective products from retailer to manufacturer and repair center were included in the model. Our aim was to model the joint effects of outsourcing repair, recycling/remanufacturing, and carbon emissions on supply chain performance. Theoretical results were obtained with the help of a numerical example and sensitivity analysis was carried out. Numerical analysis showed that the repair process together with the recycling/remanufacturing process has a positive effect on the total inventory cost of the supply chain. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Erciyes Agriculture & Animal Science is the property of Erciyes Tarim ve Hayvan Bilimleri Dergisi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım ve Teknoloji is the property of Gazi University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The classical simple assembly line balancing problem (SALBP) has been extended with many real-life applications recently. One of these extensions is assembly line balancing with sequence-dependent setup times (ALBPS). In this study, ALBPS is extended with more than one resource at each workstation. Task is performed any resource at each workstation. More than one resource at each workstation can decrease the number of setups. Thus, the required number of the workstations on the line can reduce. The problem is called assembly line balancing with resource and sequence-dependent setup times (ALBPRS). ALBPRS is to assign the task to the workstations, to assign the tasks to the resource, and to sequence the tasks performed by the same resource at each workstation simultaneously. A mathematical model and a genetic algorithm are developed to solve the problem. The benchmark data set is generated for ALBPRS and the mathematical model and genetic algorithm are tested on the generated benchmark dataset. Results show that the proposed methods are efficient and using more than one resource at each workstation decreases the total number of the workstations in many test problems. [ABSTRACT FROM AUTHOR]

Copyright of Mehmet Akif Ersoy University Journal of Education Faculty is the property of Mehmet Akif Ersoy Universitesi Egitim Fakultesi Dergisi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Projects are set of processes which aim to serve a unique product or a service in a time-bounded period. Pressure in terms of accelerating the time to market of the unique product or service has become the reality in every organization. Thus, companies need to search for new methodologies to schedule projects effectively. This paper presents a new mathematical model to schedule resource constrained projects in accordance with their logical relationships. Optimal solution of this complex model cannot be found in case of a high number of activities. Therefore, a new hybrid metaheuristic is proposed to find efficient solutions. Moreover, the proposed methodology is applied to schedule projects in a Turkish technology company. For 154 projects completed between 2018 and 2020, proposed methods finds on the average 3.91% better solution in 178 seconds compared to solutions obtained by CPLEX in 34,883 seconds. Proposed methods are also applied for 64 projects planned in 2021 and finds on the average 5% better results in 130 seconds compared to solutions found by CPLEX in 35,438 seconds. In brief, the proposed methodology provides efficient solutions with a very small number of delayed projects, reliable plans, better solution time and objective function value. [ABSTRACT FROM AUTHOR]

Copyright of International Journal of Engineering Research & Development (IJERAD) is the property of International Journal of Engineering Research & Development and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Administrative Sciences / Yonetim Bilimleri Dergisi is the property of Canakkale Onsekiz Mart Universitesi, Terzioglu Kampusu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Talaşlı imalat operasyonlarında ürün kalitesini belirleyen birçok parametre bulunmaktadır. Bu parametrelerin başında da yüzey kalitesi gelmektedir. Yüzey kalitesi; iş parçasının tribolojik, sızdırmazlık, hidrodinamik, elektrik ve ısı iletimi gibi özelliklerini etkilemektedir. İdeal pürüzlülük değerlerinin elde edilebilmesi için kesme parametrelerinin doğru bir şekilde belirlenmesi gerekmektedir. Bu çalışmada AISI 1050 çeliği kullanılarak üç farklı kesme hızı, ilerleme ve kesme derinliği ile tornalama deneyleri yapılmıştır. Deneyler sonucunda yüzey pürüzlülüğü için en etkili kesme parametreleri belirlenmiştir. Kesme parametreleri ve yüzey pürüzlülüğü arasındaki ilişki, oluşturulan matematiksel modeller ve denklemler ile ifade edilmiştir. Kesme parametrelerinin talaş oluşumuna etkileri araştırılmış ve farklı kesme parametrelerinin talaş geometrisini nasıl değiştirdiği açıklanmıştır.

Although sufficient amounts of wheat are produced in Turkey, which ranks first in the world in terms of flour export, wheat imports negatively affect the sector. In general, farmers in Turkey produce in small quantities in small production area, and deliver their products with small capacity vehicles and multiple trips. Purchased wheat is classified according to quality characteristics in collection silos, and wheat purchase is limited by harvest period. On the other hand, shipments to the factory from collection silos can be made all year around. In this paper, a 0-1 mixed integer programming formulation for wheat supply network design is proposed to supply sufficient wheat with the desired quality and lowest cost. The proposed formulation uses vehicles with different capacities and reduces the number of trips by choosing the appropriate vehicle for the load amount. In addition to the road, the formulation also considers the rail option. In its current form, the considered problem is described as a wheat supply network design problem with capacity-constraint multi-period multi-stage multi-modal multi-product. The proposed formulation has been tested using real data in a wheat flour factory operating in Konya. The formulation, which was run for three different scenarios of the company, provided sufficient and desired quality wheat by optimizing transportation costs. Computational results recommend the rail transport option in some regions. The results of the formulation are thought to be of a nature that guides the company's tactical and strategic plans. [ABSTRACT FROM AUTHOR]

This study proposes a mathematical model constructed in spherical coordinates to reveal the mass and temperature changes that occur during the freeze-drying of apricot fruit. A kind of polynomial approach known as the orthogonal collocation method was applied to find the solution of governing equations. The physical properties and some transport parameters that describe the freeze-drying of apricot fruit were estimated by using the Levenberg-Marquardt algorithm based on the nonlinear least-square method. The effect of product radius, drying temperature, and product shape on the length of the primary drying stage was investigated by the determined transport parameters in the model. Furthermore, the effect of the freezedrying process on product color and total phenolic content (TPC) was examined, and it was observed that the TPC value of apricot fruit increased from 295.60 ± 16.55 to 602.63 ± 17.74 mg GAE (Gallic acid equivalent) / 100 g DM. [ABSTRACT FROM AUTHOR]

The criteria to be used for evaluating the performance of workers vary much more than those used to evaluate the performance of office personnel. Therefore, it is more difficult to determine which criteria to use. All criteria, as much as possible, should be taken into account to evaluate the performance healthily way. However, each new criterion defined requires the collection and evaluation of a new data set. However, each new data group that needs to be collected for each employee means a new workload for businesses, and therefore business managers want to be able to evaluate the performance of their workers in the healthiest way, using as few criteria as possible. In this study, a mathematical model was proposed to determine which criteria to be used in evaluating worker performance with AHP, and the proposed approach is applied using data from a sample business and the obtained results are discussed. The criteria to be used in classical performance evaluation studies are generally determined by experts only considering their contribution to performance evaluation. In this case, the data collection workload can be too high and it may make it impossible to use the method in practice. In this study, firstly, workers' performances were calculated with Analytic Hierarchy Process using the criteria determined by the experts, and then, using the proposed multi-objective mathematical model, the criteria that could represent all the criteria with the minimum total data collection workload were determined. Since performance evaluation is carried out continuously in certain periods, working with fewer criteria that can represent all criteria ensures that the data collection workload is drastically reduced and thus the proposed method can be used in practical life. The proposed method has been applied in a plastic injection factory. As a result, 30 out of a total of 40 criteria determined by the experts were selected, with a deviation of only 4% from the performance score obtained when all criteria were selected, the workload of obtaining data was reduced by 26%. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bu araştırmada Romanov kuzularının vücut özelliklerinin gelişiminin tanımlanması amacı ile 50 Romanov kuzusunun doğumdan itibaren 180. yaş gününe kadar olan büyüme döneminde her 15 günde bir canlı ağırlık, vücut uzunluğu, cidago yüksekliği özelliklerine ilişkin kayıtlar alınmış ve elde edilen veriler ile doğrusal modellerden Linear, Kuadratik ve Kübik model, doğrusal olmayan modellerden Gompertz ve Lojistik modelleri kullanılarak büyüme eğrilerine ait parametreler hesaplanmıştır. Büyüme eğrileri içinde en iyi uyumu gösteren modelin belirlenmesinde belirtme katsayısı (R2), hata kareler ortalaması (HKO) ve ortalama mutlak sapma (OMS) değerlerinden yararlanılmıştır. Elde edilen sonuçlara göre en yüksek R2 değeri ile en düşük HKO değerleri sırası ile canlı ağırlıkta 0,992-0,591, cidago yüksekliğinde 0,993-0,441, vücut uzunluğunda 0,986-1,164 olarak tespit edilmiştir. Ele alınan bütün vücut özelliklerinde en yüksek R2 değeri kübik modelden elde edilmiştir. Büyüme eğrisi modellerine ait parametrelerin belirlenebilmesi için SPSS istatistik programı kullanılmıştır. Bu sonuçlara göre Romanov kuzularının vücut özelliklerinin gelişimini en iyi açıklayan ayrıca büyüme eğrilerine en uyumlu modelin Kübik model olduğu tespit edilmiştir.

Kalitelerine göre ayrılmış sütlerin içerikleri mikroorganizma sayısı, kimyasal değerleri birbirinden farklıdır. Farklı kaliteye sahip sütlerin karıştırılması durumunda oluşan sütün kalitesi, karışıma katılan sütler arasındaki en düşük kaliteye sahip olan süt tipinin kalitesine eşit kabul edilmektedir. Bu yüzden faklı kalitedeki sütler toplanırken karıştırılmamalıdır. Süt toplama problemi farklı noktalarda bulunan üreticilerden, kalite tiplerine göre ayrılmış çiğ sütlerin, çok tanka sahip tankerler aracılığı ile toplanması ile ilgilenmektedir. Bu çalışmada; farklı noktalarda bulunan farklı kalitede ki çiğ sütlerin, çok tanka sahip tankerler aracılığı ile belirlenen zaman limiti altında toplanmasını sağlayacak bütünleşik bir matematiksel model oluşturulmuştur. Varsayımsal bir vaka çalışmasının ILOG CPLEX ile çözülmesi ile elde edilen sonuçlar göstermektedir ki önerilen model farklı kalitedeki çiğ süt tiplerinin karıştırılmadan en etkin şekilde toplanmasına izin vermektedir. Böylece daha yüksek kalitede süt ürünleri üretilmesi mümkün olabilecektir.

The number of microorganisms and chemical values of the milks separated according to their quality are different from each other. In case of mixing different quality types of milk, composed milk quality is considered equal to the lowest quality milk type among the types of milk added to the mixture. Therefore, different types of raw milk should not be mixed during collection. The problem of milk collection is related to the collection of raw milk, which is separated according to the quality types, from the producers at different points by multi-tank tankers. In this study, an integrated mathematical model has been developed to collect different quality types of raw milk at different points under the specified time limit by means of tankers having multiple tanks. The results obtained by solving a hypothetical case study with ILOG CPLEX show that proposed model allows to optimally collect different type of raw milks without mixing. Thus, it will be possible to produce higher quality dairy products.

Bu çalışmada bir organik gübre çeşidi olan solucan gübresi üretiminin yaygınlaşması amacıyla, bu alanda yatırım yapmayı düşünen karar vericilere, yatırımın olurluluğu, farklı kısıtlar (bütçe, alan, teknik vb.) altında üretilecek gübre miktarı, oluşacak maliyetler ve grafik ile desteklenmiş ekonomik analizler açısından destek verecek bir karar destek sistemi geliştirilmiştir. Geliştirilen karar destek sisteminin karar vericiye sunacağı bilgilerin doğruluğunu sağlamak üzere öncelikle, Eskişehir il sınırlarında yer alan bir tesis ayrıntılı bir şekilde incelenmiş, solucan miktarının zaman içindeki değişimini tahmin edebilecek bir tahmin modeli oluşturulmuş ve bir solucan gübresi tesisinin olurluluk çalışmasında yer alması gereken tüm maliyet kalemleri belirlenmiştir. Ayrıca bütçe kısıtı altında üretilen solucan gübresi miktarını eniyileyecek ve seçilmesi gereken üretim yöntemi ve üretim kapasitesini belirleyecek bir karar modeli geliştirilmiştir. Geliştirilen karar destek sistemi yatırımcıların olurluluk ve ekonomik analizleri kolayca yapabilmelerini sağlayacağından, solucan üretiminin yaygınlaşmasına katkı sağlaması beklenmektedir. Bu da ülke ekonomisi, çevre ve insan sağlığı açısından olumlu sonuçlar doğuracaktır.

Copyright of Erzincan University Journal of Education Faculty / Erzincan Üniversitesi Egitim Fakültesi Dergisi is the property of Erzincan University Faculty of Education Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Turkish Operations Management (JTOM) is the property of Ankara Yildirim Beyazit University Journal of Turkish Operations Management (JTOM) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Turkish Operations Management (JTOM) is the property of Ankara Yildirim Beyazit University Journal of Turkish Operations Management (JTOM) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The subject of this study is to decide to which shelf space the raw materials will be allocated and assign the maximum amount. One should consider that space is limited, all raw materials do not have the same level of importance among themselves, and have different stock and pallet sizes. In current studies, shelf dimensions and pallets are calculated with standard dimensions. However, shelf and pallet sizes have different measurements, so in this study, a model of all situations is created. Firstly, raw materials in Class A were determined using ABC Analysis. The importance coefficients of these raw materials were determined with the multi-criteria decision-making method and the main criteria were determined so that 4 different experts could classify the raw materials in order to create the objective function of the linear model. The Fuzzy Analytical Network Process was used to create the model without ignoring these different opinions and the relationships between the criteria determined for the raw materials. The constraint equations of the model were created according to the changing capacities of the cells of the block rack systems and the maximum-minimum stock values of the raw materials. [ABSTRACT FROM AUTHOR]

Municipalities make regular strategic plans in order to use their resources effectively, indicate their objectives and goals in a more systematic manner and respond to the needs of the people living in that municipality. This study focuses on the goals proposed in the strategic plan of a municipality and aims to prioritize these goals. To this end, a two-phase solution approach is proposed. In the first phase, a trapezoidal type-2 fuzzy AHP algorithm is used to determine the weights of the goals, whereas in the second phase, an exact solution approach (mathematical model) is proposed to determine which goals should be selected by the municipality under a limited budget. Proposed models and computational results bring various managerial insights. [ABSTRACT FROM AUTHOR]

The textile industry has a huge market worldwide. While customer needs and expectations are increasing day by day, textile factories must be able to respond quickly to customer requests. In this study, assembly line balancing and performance-based worker assignment problems in a sewing workshop of a textile factory are discussed together. Three different mathematical models have been developed for the solution of the problem: M1, M2 and M3.In the M1 model, assembly line balancing and worker assignment were made so that the number of stations to be opened and the completion time of the works were minimized by taking the number of jobs and workers equal.M2 model is a nonlinear mathematical model where one or more workers can be assigned to each job in line with the data received from the business. The last model (M3) is an alternative linear model obtained by addingthe constraint that calculates the average time of the workers assigned to a job instead of the constraint that disrupts the linearityin the nonlinear model (M2). Using the pants line data, the solutions of the M1, M2 and M3 models obtained in the GAMS program were compared and discussed. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agriculture & Nature / Kahramanmaraş Sütçü İmam Üniversitesi Tarım & Doğa Dergisi is the property of Kahramanmaras Sutcu Imam Universitesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bu araştırmanın amacı, okul öncesi öğretmen adaylarının öğrenme stillerinin, matematiksel bir algoritma yöntemi kullanılarak modellenmesidir. Çalışma 2015-2016 akademik yılında Ankara ilinde bulunan bir devlet üniversitesinin okul öncesi eğitimi anabilim dalında öğrenim gören 159 lisans öğrencisi ile yürütülmüştür. Araştırmada veri toplama aracı olarak Felder ve Soloman (1994)’ın Öğrenme Stilleri Envanteri kullanılmıştır. Araştırma sonuçlarına göre öğretmen adaylarının sağ yarıküre kontrolündeki aktif, algısal ve görsel öğrenme stillerini ağırlıklı olarak tercih ettikleri saptanırken; sol yarıküre kontrolündeki sıralı (analitik) öğrenme stilini de bütüncül (global) öğrenme stiline oranla daha fazla kullandıkları ortaya çıkmıştır. Bununla beraber araştırmada yer alan öğretmen adaylarının öğrenme stillerinde yaklaşık olarak % 11 oranında sağ yarıküre temelli stillere kaydıkları belirlenmiştir. Bununla beraber geliştirilen modelleme sonucunda sapmanın fazla olduğu öğrenme stili güçlerinin de % 12 yansıtıcı/aktif ve % 16 işitsel/görsel alt boyutlarında kayba uğradığı hesaplanmıştır.

Metal cutting is widely used than other production methods. Cutting forces are the leading parameters that determine process efficiency in machining operations. Cutting forces inform us about the magnitude of energy consumption during the operation. By providing certain conditions, the creation of low cutting forces reduces the costs. This is due to the accurate determination of the cutting parameters. In this study, the experiments were performed with three different cutting speeds, three different feed rates and three different cutting depths by using of AISI 1050. As a result of the experiments, the most effective cutting parameters were determined in order to keep under control of cutting forces values and get the best results. New concepts are defined by analyzing the build-up factor. These defined concepts and the relationship between machining parameters and cutting forces are expressed by mathematical models. Thanks to the mathematical models developed with this study, the force formation is explained through parameters and the appropriate processing parameters are provided for the ideal force values. [ABSTRACT FROM AUTHOR]

Copyright of Ondokuz Mayis University Journal of Education is the property of Ondokuz Mayis University Faculty of Education and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

There are many parameters that determine the product quality in metal cutting operations. Surface roughness is the leading parameter. Surface roughness effects the work piece properties such as tribological, sealing, hydrodynamic, electrical conduction and thermal conduction. In order to obtain the ideal roughness values, the cutting parameters must be determined accurately. In this study, the experiments were performed with three different cutting speeds, three different cutting depths, three different feed rates by using AISI 1050 steel. As a result of the experiments, most effective cutting parameters were determined for surface roughness. The relation between cutting parameters and surface roughness was stated with mathematical models and equations. The effects of cutting parameters on chip formation were investigated and how different cutting parameters change chip formation was explained. [ABSTRACT FROM AUTHOR]

Copyright of Mediterranean Agricultural Sciences is the property of Akdeniz Universitesi Ziraat Fakultesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Yapılacak olan çalışmada meteorolojik veriler ile doğru üretim tahmini yapan matematiksel modellerin oluşturulması amaçlanmıştır. Yenilenebilir enerji kaynaklarında, üretim tahminlerini doğru olarak yapabilen modeller bulunmamaktadır. Bu çalışma ile üretilecek modeller sayesinde geleceğe yönelik doğru tahminler yapılmış olup, en uygun yöntem kullanılarak üretilen matematiksel modellerin doğruluğu test edilmiştir. Elde edilen tahmin modelleri ile rüzgâr ve güneş enerjisi santrallerinde kısa dönem enerji üretim tahmini yapılmıştır. Geliştirilen matematiksel modellerin doğruluğu çoklu regresyon analizi kullanılarak incelenmiştir. Bu modeller ile üretim planlaması daha kolay ve doğru bir şekilde tahmin edilmiştir.

Copyright of Beykent Üniversitesi Fen ve Mühendislik Bilimleri Dergisi is the property of Beykent Universitesi Fen Bilimleri Enstitusu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The number of microorganisms and chemical values of the milks separated according to their quality are different from each other. In case of mixing different quality types of milk, composed milk quality is considered equal to the lowest quality milk type among the types of milk added to the mixture. Therefore, different types of raw milk should not be mixed during collection. The problem of milk collection is related to the collection of raw milk, which is separated according to the quality types, from the producers at different points by multi-tank tankers. In this study, an integrated mathematical model has been developed to collect different quality types of raw milk at different points under the specified time limit by means of tankers having multiple tanks. The results obtained by solving a hypothetical case study with ILOG CPLEX show that proposed model allows to optimally collect different type of raw milks without mixing. Thus, it will be possible to produce higher quality dairy products. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering & Architectural Faculty of Eskisehir Osmangazi University / Eskişehir Osmangazi Üniversitesi Mühendislik ve Mimarlık Fakültesi Dergisi is the property of Eskisehir Osmangazi University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Malaysian football is witnessing a decrease in the number of supporters at their stadiums. Therefore, league administrators give the higher priority to this issue. We hypothesize that spectators would prefer to watch more important matches at stadiums and no matter when they are. We propose to define an importance level for each fixture. The Analytic Hierarchy Process (AHP) is utilised to obtain these importance levels. We also develop an integer programming model to assign fixtures to the timeslots in a way to maximize the number of supporters that attend matches. The outcome of the first process is used as input to this optimization model. We apply the methodology to a real case from the Super League Season in Malaysia and we believe that we produced a superior schedule which will maximize gate receipts. [ABSTRACT FROM AUTHOR]

Copyright of Journal of International Social Research is the property of Journal of International Social Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of DSI Technical Bulletin / DSİ Teknik Bülteni is the property of DSI Technical Bulletin / DSI Teknik Bulteni and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Faculty of Educational Sciences is the property of Ankara University, Faculty of Educational Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ÖZ: Müşteri tatmininin her geçen gün daha da zorlaştığı hizmet sektörlerinde, işverenler sunulan hizmetin kalitesini arttırmak ve hizmetin devamlılığını sağlamak için yeni arayışlar içine girmekteler. İşverenler, müşteriden önce hizmeti sunan kişilerin memnuniyetini sağlayarak rekabet gücünü arttırma yollarına başvurmaktadırlar. Bu yollardan biri de çalışma sürelerinin esnekleştirilmesidir. Bu çalışmada, hizmet sektörleri arasında önemli bir yere sahip olan hastanelerde ki hemşire çizelgeleme problemi için tam sayılı matematiksel bir model oluşturulmuştur. Oluşturulan modelde, klasik çizelgeleme modellerinin aksine hemşirelerin işe başlama saatlerine esneklik getirilmiştir. Modelin başlıca amacı, hemşirelerin kendi tercihlerine göre haftalık çizelgelerinin oluşturulmasıdır. Oluşturulan model, gerçek veriler kullanılarak bir üniversite hastanesinin genel cerrahi bölümünde denenmiştir. Modelin, %99,6 oranında hemşire tercihlerini yerine getirdiği görülmektedir. Anahtar Kelimeler: Esnek Çalışma Saatleri, Hemşire Çizelgelemesi, Matematiksel Model, Tam Sayılı Programlama. ABSTRACT: In the service industry, customer satisfaction becomes more difficult with each passing day, employers have looked for new paradigms and ways to make service quality better and to keep service facilities reliable. Therefore, with the purpose of increasing their competitive power, employers give more importance to their employees who have direct relation with customers than they do to their customer. One of the new paradigms is make working hours flexible. In this study, an integer programming model is proposed for the nurse scheduling problem in the hospitals which are one of the most important service industries. On the contrary of classical nurse scheduling model, developed model has made flexible to starting time. The main aim of the model is make a schedule for nurses according to their preferences. The developed model is applied on a surgery department of one university hospital with real data. According to results, model can satisfy 99,6% of the nurses with their schedule based on their preferences. Keywords: Flexible Working Hours, Nurse Scheduling, Mathematical Model, Integer Programming.

The problem of exam scheduling is a kind of scheduling problem that is studied academically, in which the exams of a certain number of courses is assigned to specific time intervals taking certain constraints into consideration. In most faculties of universities, exam schedules are made manually, which is both time-consuming and errorprone. The objective of this study is to develop a mathematical model that can solve exam scheduling problem in a shorter time than manual schedules and without error. Minimizing total number of classrooms assigned is determined as the objective function of the model. When the total number of classrooms assigned is minimized, the number of tasks per exam invigilator (exam superviser or assistant, proctor) is also minimized. A binary integer programming model is developed for this purpose. [ABSTRACT FROM AUTHOR]

Copyright of Journal of International Social Research is the property of Journal of International Social Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, it is described the general forms of fractional-order differential equations and asymtotic stability of their system’s equilibria. In addition that, the stability analysis of equilibrium points of the local bacterial infection model which is fractional-order differential equation system, is made. Results of this analysis are supported via numerical simulations drawn by datas obtained from literature for mycobacterium tuberculosis and the antibiotics isoniazid (INH), rifampicin (RIF), streptomycin (SRT) and pyrazinamide (PRZ) used against this bacterial infection. [ABSTRACT FROM AUTHOR]