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Öğe EXPERT SYSTEM BASED IDENTIFICATION AND EXTRACTION OF DETAILED DIMENSIONS FOR GEARS(Gazi Univ, Fac Engineering Architecture, 2008) Çiçek, AdemIn this paper, an expert system software has been developed and integrated to identify the spur and helical gears, and to extract their detailed dimensions from solid models designed in a CAD system. The STEP files of CAD models of gears have been used as input to the whole system. The algorithm is executed in two main stages. In the first stage, the spur and helical gears are identified by expert system by reasoning STEP physical file of CAD model belonging to any gear and rules represented in a knowledge base constructed for the expert system. In the second stage, detailed dimensions of the identified gears are extracted via data obtained from STEP file. Although the developed approach is only applied to spur and helical gears in this study, it can be successfully implemented to different part families such as bolts, nuts, washers, pipes etc. for other CAD/CAM applications.Öğe Development of a 3-axis Parallel Kinematic Machine for Milling Wood Material - Part 1: Design(North Carolina State Univ Dept Wood & Paper Sci, 2017) Ayyıldız, Elmas Aşkar; Ayyıldız, MustafaA 3-axis parallel kinematic machine tool and advanced control system with programming in G-code for the milling of wood material are described in detail. This parallel kinematic machine is based on a 3-PSS (prismatic link, spherical link, and spherical link) parallel mechanism. A programming system and control based on a real-time PC windows platform and Mach3 software system was implemented for this tool. Finally, a model application of a programming system developed for a three-degree-of-freedom linear delta parallel machine was presented, and the workability for milling wood material (medium-density fibreboard) was shown.Öğe Selection of optimal machining conditions for the composite materials by using Taguchi and GONNs(Elsevier Sci Ltd, 2014) Erkan, Ömer; Demetgül, Mustafa; Işık, Birhan; Tansel, İbrahim NurMilling has been widely used in industry for machining parts to their final dimensions without requiring additional operations. Extensive experimental work is necessary to determine the optimal cutting conditions of glass-fiber reinforced polymer composite (GFRP) materials to achieve the desired surface quality. In this study, a series of machining operations were done for data collection by varying the flute number, feed rate, depth of cut and cutting speed. The relationship between the cutting parameters of end milling operations and the surface roughness of the machined surface was studied. For the analysis of the data and selection of the optimal cutting parameters the Taguchi method and genetically optimized neural network systems (GONNs) were used. Published by Elsevier Ltd.Öğe RECOGNITION OF 3D MACHINING FEATURES USING FEATURE MATRICES(Gazi Univ, Fac Engineering Architecture, 2010) Çiçek, Adem; Aslantaş, KubilayFeature recognition is regarded as an ideal solution to integrate the component design and manufacturing processes. Integration of computer aided design (CAD) and computer aided manufacturing (CAM) systems is a vital importance in the building of computer integrated manufacturing (CIM) systems. In this paper, a matrix based feature recognition approach is developed for CAD and CAM integration. In feature recognition system, STEP AP-203 graphic standard is used to obtain geometric and topological data from 3D CAD models. Adjacency relations belonging to all faces on a component are extracted by use of entities represented in the STEP file and represented in a square matrix called as component matrix. Also, machining features are coded into a matrix called feature matrix, which will be located into database. In the developed system, the machining features are recognized by retrieving feature patterns corresponding to feature matrices within the component matrix. The developed algorithm is applied to interacting features, and is used a matrix matching process to recognize the interacting features on the component. The algorithm has been implemented to individual and interacting polyhedral features. The obtained results are very efficient for the implemented feature types.Öğe Predictive modeling of geometric shapes of different objects using image processing and an artificial neural network(Sage Publications Ltd, 2017) Ayyıldız, Mustafa; Çetinkaya, KerimIn this study, an artificial neural network model was developed to predict the geometric shapes of different objects using image processing. These objects with various sizes and shapes (circle, square, triangle, and rectangle) were used for the experimental process. In order to extract the features of these geometric shapes, morphological features, including the area, perimeter, compactness, elongation, rectangularity, and roundness, were applied. For the artificial neural network modeling, the standard back-propagation algorithm was found to be the optimum choice for training the model. In the building of the network structure, five different learning algorithms were used: the Levenberg-Marquardt, the quasi-Newton back propagation, the scaled conjugate gradient, the resilient back propagation, and the conjugate gradient back propagation. The best result was obtained by 6-5-1 network architectures with single hidden layers for the geometric shapes. After artificial neural network training, the correlation coefficients (R-2) of the geometric shape values for training and testing data were very close to 1. Similarly, the root-mean-square error and mean error percentage values for the training and testing data were less than 0.9% and 0.004%, respectively. These results demonstrated that the artificial neural network is an admissible model for the estimation of geometric shapes using image processing.Öğe PARAMETRIC GEAR WHEEL APPLICATIONS IN COMPUTER AIDED DESIGN(Gazi Univ, Fac Engineering Architecture, 2010) Ayyıldız, Mustafa; Çiçek, Adem; Kara, FuatIn this study, a software has been developed to parametrically draw and model the gear wheels and gear wheel pairs in a CAD (Computer Aided Design) environment. In the software development, a hybrid programming structure using Visual BASIC and AutoLISP programming languages is used for the proposed software. The programming languages are easy and commonly used. In the software system, gear wheels or gear wheel pairs are sized by inputting parameters such as modules, transmission ratios, teeth numbers, etc. and then they are automatically drawn and modeled in CAD environment. This study presents an auxiliary program which is rapid and functional to the designer for drawing and modeling of gear wheels.Öğe Modeling for prediction of surface roughness in milling medium density fiberboard with a parallel robot(Emerald Group Publishing Ltd, 2019) Ayyıldız, MustafaPurpose This paper aims to discuss the utilization of artificial neural networks (ANNs) and multiple regression method for estimating surface roughness in milling medium density fiberboard (MDF) material with a parallel robot. Design/methodology/approach In ANN modeling, performance parameters such as root mean square error, mean error percentage, mean square error and correlation coefficients (R-2) for the experimental data were determined based on conjugate gradient back propagation, Levenberg-Marquardt (LM), resilient back propagation, scaled conjugate gradient and quasi-Newton back propagation feed forward back propagation training algorithm with logistic transfer function. Findings In the ANN architecture established for the surface roughness (Ra), three neurons [cutting speed (V), feed rate (f) and depth of cut (a)] were contained in the input layer, five neurons were included in its hidden layer and one neuron was contained in the output layer (3-5-1).Trials showed that LM learning algorithm was the best learning algorithm for the surface roughness. The ANN model obtained with the LM learning algorithm yielded estimation training values R-2 (97.5 per cent) and testing values R-2 (99 per cent). The R-2 for multiple regressions was obtained as 96.1 per cent. Originality/value The result of the surface roughness estimation model showed that the equation obtained from the multiple regressions with quadratic model had an acceptable estimation capacity. The ANN model showed a more dependable estimation when compared with the multiple regression models. Hereby, these models can be used to effectively control the milling process to reach a satisfactory surface quality.Öğe Comparison of four different heuristic optimization algorithms for the inverse kinematics solution of a real 4-DOF serial robot manipulator(Springer London Ltd, 2016) Ayyıldız, Mustafa; Çetinkaya, KerimIn this study, a 4-degree-of-freedom (DOF) serial robot manipulator was designed and developed for the pick-and-place operation of a flexible manufacturing system. The solution of the inverse kinematics equation, one of the most important parts of the control process of the manipulator, was obtained by using four different optimization algorithms: the genetic algorithm (GA), the particle swarm optimization (PSO) algorithm, the quantum particle swarm optimization (QPSO) algorithm and the gravitational search algorithm (GSA). These algorithms were tested with two different scenarios for the motion of the manipulator's end-effector. One hundred randomly selected workspace points were defined for the first scenario, while a spline trajectory, also composed of one hundred workspace points, was used for the second. The optimization algorithms were used for solving of the inverse kinematics of the manipulator in order to successfully move the end-effector to these workspace points. The four algorithms were compared according to the execution time, the end-effector position error and the required number of generations. The results showed that the QPSO could be effectively used for the inverse kinematics solution of the developed manipulator.Öğe Application of Taguchi method for determining optimum surface roughness in turning of high-alloy white cast iron(Elsevier Sci Ltd, 2013) Günay, Mustafa; Yücel, EmreThis paper focused on optimizing the cutting conditions for the average surface roughness (R-a) obtained in machining of high-alloy white cast iron (Ni-Hard) at two different hardness levels (50 HRC and 62 HRC). Machining experiments were performed at the CNC lathe using ceramic and cubic boron nitride (CBN) cutting tools on Ni-Hard materials. Cutting speed, feed rate and depth of cut were chosen as the cutting parameters. Taguchi L-18 orthogonal array was used to design of experiment. Optimal cutting conditions was determined using the signal-to-noise (S/N) ratio which was calculated for R-a according to the "the-smaller-the-better" approach. The effects of the cutting parameters and tool materials on surface roughness were evaluated by the analysis of variance. The statistical analysis indicated that the parameters that have the biggest effect on R-a for Ni-Hard materials with 50 HRC and 62 HRC are the cutting speed and feed rate, respectively. Additionally, the optimum cutting conditions for the materials with 50 HRC and 62 HRC was found at different levels. (C) 2012 Elsevier Ltd. All rights reserved.Öğe CNC tel erozyon için tasarlanan DXF tabanlı bir BDT/BDİ sistemi(2008) Çiçek, AdemBu makalede, CNC tel erozyon tezgahı için geliştirilen DXF tabanlı bir BDT/BDİ sistemi sunulmuştur. BDT/BDİ sistemi, BDT ortamında tasarlanan 2 boyutlu çizimler için hem bir otomatik CNC kod türetme modülünü, hem de takım yolunu canlandıran bir simülasyon modülünü içermektedir. Bilgisayarda yazılım geliştirmek için Visual BASIC ve Visual LISP programlama dilleri kullanılmıştır. Geliştirilen programla, BDT ortamında tasarlanan 2 boyutlu çizimler otomatik olarak DXF formatına dönüştürülmüş ve bu formatta temsil edilen geometrik unsurlar değerlendirilerek çizime ait bilgiler çıkarılmıştır. Bu bilgiler kenar eğrisi tipi (doğru, çember, yay, vs.), kenar eğrilerinin koordinatları (başlangıç ve bitiş noktaları, merkez noktaları, vs.) ve bazı kenar eğrisi nitelikleridir (yarıçap, yayın başlangıç ve bitiş açıları, vs.). Bu bilgiler kullanılarak BDT ortamında kullanıcı tarafından tasarlanan herhangi bir çizim için takım yolu oluşturulabilmekte ve FANUC formatına uygun CNC kodları türetilebilmektedir. Aynı zamanda, takım yoluna uygun olarak takım hareketi BDT ortamında canlandırılabilmektedir.Öğe Dişlilerin uzman sistem tabanlı tanımlanması ve detaylı boyutlarının çıkarılması(2008) Çiçek, AdemBu makalede, bir BDT sisteminde tasarlanan katı modellerden düz ve helis dişlileri tanımlamak ve detaylı boyutlarını çıkarmak için bir uzman sistem yazılımı geliştirilmiş ve dişli tanımlama sistemine entegre edilmiştir. Dişlilere ait BDT (Bilgisayar Destekli Tasarım) modellerinin STEP (Standard for the exchange of product data model) dosyaları tüm sisteme girdi olarak kullanılmıştır. Algoritma iki aşamada yürütülmektedir. İlk aşamada, uzman sistem için tasarlanan bir bilgi tabanında temsil edilen kurallar ve herhangi bir dişliye ait BDT modelinin STEP fiziksel dosyası muhakeme edilerek düz ve helis dişliler uzman sistem tarafından tanımlanmaktadır. İkinci aşamada, tanımlanan dişlilerin detaylı boyutları, STEP dosyasından elde edilen veri sayesinde çıkarılmaktadır. Geliştirilen yaklaşım, bu çalışmada sadece düz ve helis dişlilere uygulanmasına rağmen, farklı BDT/BDİ (Bilgisayar Destekli İmalat) uygulamaları için cıvata, somun, rondelâ, boru, vs. gibi farklı parça ailelerine başarı ile uygulanabilir.Öğe Fe-Cu-C çeliklerine mangan ilavesinin mekanik özelliklere etkisi(2007) Uygur, İlyasBu çalışmada, farklı oranlarda Cu, C, ve ferromangan tozları karıştırılarak Fe-Cu-Mn-C çelik parçalar, toz metalurjisi yöntemi ile üretilmiştir. Karıştırılan tozlar, farklı presleme basınçlarında, 1120 C sıcaklıkta ve amonyak atmosferinde 30 dakika süreyle sinterlenmiştir. Üretilen parçalarda, presleme basıncının gözenekliliğe ve çekme mukavemetine; toz element oranlarının ise sertlik, tokluk ve çekme mukavemetine etkisi incelenmiştir. Presleme basıncının artışı, üretilen ürünlerde gözenekliliğin azalmasını ve çekme dayanımının artmasını sağlamıştır. Çekme deneylerinde, elde edilen mukavemet değerleri, karışım içerisindeki, Cu, C ve mangan oranlarının artışı ile artmaktadır. Ayrıca karışım içerisindeki bu elementlerin varlığı sertliği de artırmaktadır. Kırılama tokluk değerleri ise sertlik ve çekme dayanımına bağlı olarak azalmaktadır.Öğe Bilgisayar destekli tasarımda parametrik dişli çark uygulamaları(2010) Ayyıldız, Mustafa; Çiçek, Adem; Kara, FuatBu çalışmada, dişli çark ve dişli çark çiftlerinin BDT (Bilgisayar Destekli Tasarım) ortamında parametrik olarak çizimi ve modellenmesi için bir yazılım geliştirilmiştir. Yazılım geliştirmede, yaygın bir kullanım alanına sahip ve diğer programlama dillerine göre oldukça basit olan Visual BASIC ve AutoLISP programlama dillerinin etkileşimli olarak kullanıldığı karma bir programlama yapısı tercih edilmiştir. Sistemde, modül, diş sayısı, iletim oranı vb. gibi parametreler kullanıcı tarafından girilerek, dişli çark veya dişli çark çiftleri boyutlandırılmakta ve daha sonra BDT ortamında dişli çarkların çizimi veya modellenmesi otomatik olarak yapılabilmektedir. Bu çalışma, dişli çark çizimi ve modellenmesi için tasarımcıya hızlı ve işlevsel bir yardımcı program alternatifi sunmaktadır.Öğe Al ve Yerleştir Robot Otomasyonu İçin Bir Çerçeve Çalışması(2018) Ayyıldız, MustafaRobotik uygulamalarda görme destekli sistemlerin kullanımı giderek yaygınlaşmakta ve görüntü işleme metodu kullanılarak robotikdestekli al ve yerleştir uygulamaları geliştirilmektedir. Bu çalışmada, al ve yerleştir robotun imalatı yapılmış ve üretim hattı üzerindekiürünlerin anlık resim bilgileri bir kamera yardımıyla alınmıştır. Robotun çalışma alanı içerisine giren ürünlerin çalışma hattındanalınarak çıkış hattına yerleştirilmesi için robotun yörünge planlaması yapılmıştır. Bunun için ürünün ağırlık merkezinin koordinatlarıve üretim hattında bulunduğu konumun koordinatları bulunarak robota gönderilmiştir. Robota gelen koordinat bilgilerine göre al veyerleştirme işlemi gerçekleştirmektedir. Bu çalışma ile otomasyon sektöründeki küçük ve orta ölçekli işletmeler için ihtiyaca yönelikistenen tüm uyarlamaların görüntü işleme fonksiyonlarıyla kolaylıkla yapılabilecek bir sistem geliştirilmesi amaçlanmaktadır. Özellikleseri üretim yapılan plastik şişe, boru gibi parçaların form kontrolü, en boy ölçümü gibi kontrolleri, eksik parça kontrolü, modele göremontaj hatası kontrolü gibi uygulama alanı olan sektörlere adapte edilebileceği düşünülmektedir.Öğe The effect of parity on bone mineral density in postmenopausal turkish women [Postmenapozal kadinlarda do?um sayisinin kemi?k mi?neral yo?unlu?u üzeri?ne etki?si?](2010) Baş, Ersun; Yazıcı, Selma; Baki, Ali Erdem; Çalık, Yalkın; Yavuz, Metin; Önder, Elif; Ataoğlu, SafinazA lot features, belonging to reproductive periods of women can affect the development of osteoporosis. We have aimed to search whether one of the reproductive factors, which is parity, is a risk factor for the progression of postmenopausal osteoporosis or not. This research has been realized on 328 postmenopausal women who have applied to Physical Medicine and Rehabilitation Polyclinic. Patients, who have secondary osteoporosis and risk factors, have not been included in this research. The patients have been categorized into 4 groups, such as patients who have never given birth, given birth once and twice, three and four times, five times and over. Bone mineral density of the patients have been examined from femoral neck and lomber vertebrae region (L1-L4). As a result of statistical analysis, a negative correlation has been found both in bone mineral density of femoral neck and lomber vertebrae with parity (p=0.002, p=0.010, respectively). When the patients are examined according to their age group, a significant relation has been found between parity and bone mineral density only in 50-60 age group. A significant relation has not been found between parity and osteoporotic fracture. It has been found that increased parity is a factor, decreasing the bone mineral density. We have concluded that the early detection and treatment of osteoporosis can be realized with the search of the parity, while the risk factors for osteoporosis are being examined on women who are in postmenopausal period. Finally, it has been concluded that since many different results have been concluded from this subject, new studies must be done so as to enlighten this subject.Öğe Drag chain pallet transport system design and implementation(2013) Ayyıldız, Mustafa; Çetinkaya, KerimMaterial handling systems, the most important part of today's production systems, plays an ever increasing role in the productivity of factories. Although the manufacturing industry has grown a lot, selection of the material transportation system that can meet the requirements of the industry is rather difficult and complicated. This article presents an alternative drag chain pallet conveyor design and micro controller based experimental study by checking the speed and direction through the use of PC interface. The system displays five different working speeds and cycle times with load and no load for weight and pallet numbers. Cycle times for the conveyor display a good performance for practical applications. © Sila Science.Öğe An evaluation on machining processes for sustainable manufacturing(2013) Günay, Mustafa; Yücel, EmreSustainable manufacturing consists of environmental protection, profitability and societal benefit for all industrial areas. Manufacturing practices are investigated for optimize production efficiency while minimizing environmental impact and maintaining social equity. It can be achieved through changes in products, processes and systems related to the sustainability issues. In sustainable manufacturing process, the natural resources which are key elements of sustainability must be used prudently by academic, scientific, cultural and human organizations. In this context, sustainable machining can be defined as a process which has been performed of sustainable manufacturing by using alternative machining technologies such as cryogenic machining, high pressure jet assisted machining. Sustainable machining investigates the conflict and synergy between economical and environmental considerations as well as the effect of system boundaries in determining optimum machining conditions. This paper presents a general evaluation on the importance of sustainable machining technologies in obtaining sustainable manufacturing objectives.
