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Detection and localization of emitters in the presence of multipath
Get PDFYön bulma işlemi kısaca DF (Direction Finding, Yön Bulma) veya AOA (Angle of Arrival, Geliş Açısı) olarak ifade edilmektedir. Antenler, alıcı, sayısal kart ve bilgisayardan oluşan sisteme de DF (Direction Finding, Yön Bulma) sistemi denmektedir. DF sistemi tek olarak sadece vericilerin yönünü tespit edebilmektedir. Eğer amaç vericilerinin konumunun belirlenmesi ise ortamda en az iki DF sistemi bulunması gerekmektedir. Bu çalışmada telsiz vericilerinin sayılarının ve yerlerinin tespiti için yeni bir yöntem önerilmiştir. Telsiz vericilerinin sayısının ve yerinin tespitinde MDL (Minimum Description Length, Minimum Tanımlama Uzunluğu) tabanlı ITC (Information Theoretic Criteria) algoritması ile önce ortamdaki yol sayısının daha sonra MUSIC (Multiple Signal Classification, Çoklu İşaret Sınıflandırma) algoritması ile vericilerin yönlerinin belirlenmesi önemli bir aşamadır. MUSIC spektrumundaki her bir tepe her bir yolun geliş açısına karşılık gelecektir. Fakat çoklu yansımalı ortamlarda bir vericiden birden fazla yoldan işaret yayılacağından DF için ek çalışmalar gerekecektir. MVBF (Minimum Variance Beamforming, Minimum Varyans Huzme Şekillendirme) huzme şekillendirme algoritması kullanılarak her yoldan gelen işaretlerin zaman ekseni verileri elde edilir ve aralarındaki korelasyon katsayıları hesaplanır. Bu korelasyon katsayıları kullanılarak işaretlerin aynı kaynaktan yayılıp yayılmadıklarına karar verilir. Böylece verici sayısı ve onların yönleri tespit edilmektedir. Performans analizleri gerçek zamanlı deneylerle elde edilerek sunulmaktadır. Önerilen tekniğin etkinlik testi, tam yansımasız oda içerisinde iki kaynaklı denemelerle gerçekleştirilmiştir. Dış ortamda da başarılı denemeler yapılmıştır. Anahtar Kelimeler: DF, dizilim anten, huzme şekillendirme, yön tespit.Direction Finding (DF), or in other words, estimation of Angle of Arrival (AOA), has been an active research area since the beginning of the 20th century. DF has several application areas such as, military applications, GSM with improved channel capacity, localization of illegal transmitters such as TV and radio stations, or, of a mountaineer losing his/her path, in addition to spectrum monitoring.When multiple sources are incident on an antenna array simultaneously, classical DF methods, such as interferometry and Doppler cannot resolve these sources. An effective solution to the problem is to use high-resolution subspace-based algorithms. Multiple Signal Identification and Classification (MUSIC) is the most powerful and widely used subspace-based method. MUSIC is known to successfully resolve two or more sources if they are incoherent. However, in practice, signals often propagate in multipath environments. Thus, a source signal is incident on the array from many paths, which implies that coherent signals at different angles will be received by an array.For source localization with MUSIC in a multipath environment, it is critical to initially detect the number of incident paths. The simplest such algorithms are based on counting the smallest eigenvalues of the array covariance matrix. Information Theoretic Criteria (ITC) is advanced algorithm for path enumeration widely used, such as the Akaike Informatin Criteria (AIC) and Minimum Description Length (MDL). Just as in MUSIC, these ITC algorithms are also affected in a multipath environment. This is due to the fact that signal coherence in a multipath environment alters the eigenstructure of the sensor array's correlation matrix, which in turn affects the performance of both MUSIC and ITC. MDL was proposed for source enumeration in the presence of multipath and signal coherence. A recent solution proposed for the problem of signal coherence is the Spatial Smoothing (SS) preprocessing algorithm. SS essentially removes the effect of coherency between incoming signals in the eigen-structure of the correlation matrix. Therefore, source localization process involves the following steps: First, the array antenna output is processed to form a sample covariance matrix, then SS is applied to this matrix, after which the number of signals are estimated and finally, based on these, MUSIC is used to generate an angle spectrum.It is important to note that in a multipath environ-ment, ITC with spatial smoothing merely detects the number of paths, i.e., the signals originating from sources directly or incident from the reflectors, and then the MUSIC algorithm localizes all these signals in the angle/AOA pseudospectrum. In other words, ITC and/or the MUSIC-AOA pseudospectrum, indicate the number of paths and not the number of independent sources present in a multipath environment. This is a significant problem if the objective is to localize actual independent sources in a multipath environment.In this study, the minimum description length information-theoretic algorithm is used for the joint detection and localization of multiple RF transmitters in a multipath environment is to enumerate the number of paths and then to measure the angle of arrival of each path using an antenna array with a high resolution direction finding algorithm such as MUSIC. Those possible propagation paths are the angles corresponding to the peaks of the MUSIC pseudospectrum. Since more than one path may correspond to a single emitter source, further processing is required. The time domain signals of these paths are then extracted with minimum variance beamforming in order to estimate their corre-lation coefficients with each other. These correlation coefficients are used to decide whether or not these paths correspond to the same emitter. Hence, the number of emitters and their angle of arrivals are jointly estimated. Performance analysis of the method is presented via real-time laboratory experimentation and discussed in this paper. To demonstrate the effectiveness of the proposed technique, experiments with two sources are conducted in an anechoic test chamber. Keywords: DF, direction finding, array antenna, beamforming, MVBF
P and PI controller design for systems with unstructured uncertainty
Get PDFBu çalışmada, yapısal olmayan belirsizliğe sahip tek girişli-tek çıkışlı doğrusal zamanla değişmeyen sistemleri kapalı çevrimde dayanıklı kararlı kılan oransal (P) ve oransal-integral (PI) kontrolörlerin tam bir kümesini bulmak için yeni yöntemler önerilmiştir. Böyle bir sistemi dayanıklı kararlı kılan tüm oransal kontrolörleri hesaplamak için önerilen yöntem, temelde Nyquist teoreminin bir genelleştirilmesine dayanır. Yapısal olmayan belirsizliklere sahip bir sistemin Nyquist eğrisi, tek bir eğri olmayıp reel ekseni bölgeler biçiminde kesen bir eğri ailesi biçimindedir. Bu eğri ailesi, belirsizlik disklerinden oluşan bir bantın içinden geçer. Nominal sistemi kararlı yapan kazançlar ile belirsizlik bantının reel ekseni kesim yerlerinden bulunan belirsizlik kazanç kümelerinden yararlanarak sistemi kapalı çevrimde dayanıklı kararlı kılan kazançların hesabı hızlıca yapılabilir. İki reel polinomun köklerinin hesabını gerektiren bu yöntemin bir parametre üzerinde herhangi bir tarama yapmayı gerektirmemesinden dolayı literatürdeki yöntemler üzerine avantajı da vardır. PI kontrolör parametrelerinin kutupsal koordinatlarda yazılmasıyla bulunan yeni sistem için birim daire taratılarak ve bu yöntemden elde edilen sonuçlardan da yararlanılarak dayanıklı kararlı yapan PI kontrolörlerin tam bölgesi hesaplanabilir. Ayrıca yapısal olmayan belirsizlik içeren sistemi dayanıklı kararlı kılan PI kontrolörleri bulmak için parametre uzayı yaklaşımını kullanan geometrik tabanlı iki yeni yöntem de önerilmiştir. Bu yöntemler, belirsizlik disklerinin orijini içermesi ve içermemesine göre iki aşama içerirler. Birinci yöntem, dayanıklı kararlı yapan PI kontrolörlerin tam bölgesini hesaplayan yavaş bir yöntemken; diğeri ise dayanıklı kararlı yapan PI kontrolörlerin yaklaşık bölgesini veren hızlı bir yöntemdir. Anahtar Kelimeler: P ve PI kontrol, dayanıklı kontrol, Nyquist teoremi, parametre uzayı yaklaşımı.In controller design, it is essential to achieve stability of the closed-loop system and various performance specifications. Frequency domain criteria such as gain margin, phase margin and norms of the closed-loop transfer functions as well as time domain criteria such as settling time, rise time and overshoot can be counted among important performance specifications. Most of the controllers used in the practical world are low order controllers such as P, PI and PID controllers. It is possible to see that methods for finding stabilizing low order compensators can be considered in three main categories: methods based on Nyquist theorem, methods based on a generalized version of the Hermite-Biehler theorem, and methods based on parameter space and the concept of singular frequencies.Robust stabilization of continuous time single-input single-output (SISO) linear time invariant (LTI) systems with multiplicative uncertainties is considered in this study. In particular, it has been shown that all P and PI controllers that robustly stabilize a given uncertain SISO LTI system can be found by utilizing a generalization of the Nyquist theorem and the parameter space approach, respectively. The generalization of Nyquist stability criterion suggests to determine the number of the unstable poles for gain intervals obtained by calculating the location and direction of the crossing of the Nyquist plot with the real axis. A stable characteristic polynomial, whose roots are in the left half plane, becomes unstable if and only if at least one root crosses the imaginary axis. The parameter values of the root crossing form the stability boundaries in the parameter space, which can be classified into three cases: the real root boundary, where a root crosses the imaginary axis at the origin (substitute and in the characteristic polynomial), the infinite root boundary, where a root leaves the left half plane at infinity (for ) and the complex root boundary, where a pair of conjugate complex roots crosses the imaginary axes (for ). These stability boundaries seperate regions in which the number of closed loop system unstable poles do not change in the parameter space.Sometimes, it is not possible to represent uncertainties in a system model with parametric uncertainties. Such uncertainties are usually encapsulated in a norm bounded system block that acts on a nominal system in an additive or multiplicative manner. Although it is possible to find robust controllers that can stabilize systems with such uncertainties by the help of control theory, the resulting compensators are usually of high order (at least as high as the order of the plant) and therefore impractical in many cases. Several attempts exist to put constraints on the order of controllers in the literature. However, many of these approaches suffer from computational intractability. In many practical cases direct determination of the set of P and PI controllers that provide robust stability of SISO LTI systems with unstructured uncertainty is required. To the best knowledge of authors, there is no such direct methods available in the literature for this purpose. The main aim of this paper is to provide such methods. Nyquist plot of a system with multiplicative uncertainties is a family of curves rather than a single curve and crosses the real axis in segments of the real axis instead of at single points. Actually, the frequency response of a system with unstructured uncertainty at a given frequency is a disk. A new method is proposed to determine all stabilizing P and PI controllers for a given system with multiplicative uncertainty. The method is applicable to systems with unstable or nonminimum phase transfer functions and/or weight functions. Proposed method involves calculation of roots of two real polynomials and does not require any search or gridding over a parameter (for P control), and as a result offers computational advantages over existing methods in literature. Although it is assumed that the nominal system does not have any poles on the imaginary axis in derivations of formulations, it is actually possible to extend the results to cover such cases rather easily. In this study, two new geometric methods are also proposed to find the set of PI controllers that robustly stabilize a given system with unstructured uncertainty. The first method gives exact set of robustly stabilizing PI controllers; but it is slow. An alternative method suggests approximation set of robustly stabilizing PI controllers; but it is faster than the first one. Keywords: P and PI control, robust control, Nyquist theorem, parameter space approach.
Expansion of non-spherical media during fluidization
Get PDFLiquid-solid fluidization has a number of applications in engineering. The expansion of granular filter media during backwashing is of particular interest. Another area of application that is of growing importance is fluidized-bed reactors used in wastewater treatment. It is important to have an understanding of fluidization principles and an ability to predict bed expansion as a function of liquid velocity to design such systems properly. More often than not, the media involved are not spherical and it is necessary to have an expansion model that can be applied to beds of non-spherical particles. Numerous equations have been proposed to predict the expansion of liquid fluidized beds of spherical particles. Very few general equations exist, however, for non-spherical media. Furthermore, the accuracies of the expansion models for non-spherical media have not been evaluated or compared in a conclusive manner to this date. This study considers the expansion of beds of possibly non-spherical particles during particulate fluidization. New experimental data with both spherical and non-spherical media are presented. Fluidization experiments have been carried out with glass balls of eight different sizes (1.11, 1.19, 2.03, 2.99, 3.18, 4.03, 4.98 and 6.01 mm), plastic balls of three different sizes (1.97, 2.48 and 2.87 mm), ten sieved fractions of silica sand, eleven sieved fractions of crushed glass, and seven sieved fractions of perlite. Perlite and crushed glass were included in this study because their properties (densities and sphericities) are different than those of silica sand, and as such they can provide additional fluidization data. It may also be noted that both materials have been considered as substitutes for silica sand in rapid filters. To obtain additional fractions of crushed glass material, particles retained in the topmost sieve tray were crushed again and sieved. In this manner sufficient quantities of additional fractions of crushed glass were obtained. Glass fractions obtained by repeated crushing and sieving were observed to have higher sphericity values. Using this procedure, crushed glass fractions with approximately the same size and density but different sphericities were produced. This allowed the collection of additional fluidization data to investigate the effect of shape on expansion behavior.The sand, perlite, and crushed glass fractions were obtained by a manual sieving procedure followed by an additional 1 minute of manual sieving such that the change in weight during the latter was less than 1% for each fraction. Densities were measured by a water-displacement technique. Equivalent diameters have been measured by counting and weighing 200 grains of each fraction. Porosities were calculated from bed weight, bed height, and density values. Sphericity of each material was determined using fixed-bed head loss data in conjunction with the Ergun equation. For all the materials studied in this work, sphericity values calculated using fixed-bed head loss measurements and the Ergun equation allowed successful prediction of the effect of particle shape on bed expansion during fluidization. Sphericity values of the materials studied was found to be 0.74, 0.66, 0.42 and 0.55 for sand, perlite, crushed glass and crushed glass produced by repeated crushing, respectively. For the eight different sizes of glass and plastic balls, the calculated sphericities by using the Ergun equation were always close to 1.0. A new equation is developed by analyzing fluidization data from the literature and the data collected in this work. The proposed equation represents the mentioned data very accurately and can be used to predict the expansion of both spherical and non-spherical media.The non-spherical particle data fall below the curve for spheres on the friction factor versus the modified Reynolds number diagram. For the materials studied, it has been observed that this shape effect depends on the Reynolds number and is considerably stronger than documented previously in the literature. The proposed equation can be used to predict the expansion of both spherical and non-spherical media. When applied to the non-spherical particle data obtained in this work (bed expansions from 20% to about 100%, sphericities between 0.410 and 0.757), the mean error in the predicted porosity values is 2.45%. The corresponding mean error that results from Dharmarajah-Cleasby (1986) equation is 4.4%. Keywords: Filter backwash hydraulics, fluidization, filter material, sphericity.Akışkan yatakların genişlemesi sırasındaki hız-gözeneklilik ilişkileri üzerine önerilen pek çok denklem mevcuttur. Bununla birlikte bu denklemlerin tamamına yakını sadece küresel malzemelere uygulanabilir nitelikte olup küresel olmayan tanecikler için önerilen az sayıda modelin büyük çoğunluğu da ampiriktir ve şekil faktörü etkisini açık bir şekilde ortaya koymamaktadırlar. Ayrıca küresel olmayan tanecikler için geçerli genişleme modellerinin doğrulukları sistematik bir şekilde değerlendirilmemiş ve karşılaştırılmamıştır. Bu çalışmada küresel olmayan malzemeler ile ilgili akışkanlaşma deneyleri yürütülmüştür. Bu amaçla 10 farklı kum, 7 farklı perlit ve 11 farklı kırılarak oluşturulmuş cam fraksiyonu hazırlanmış, malzemelerin şeklinin akışkanlaşma sırasındaki davranışları üzerine etkisini belirlemek amacıyla sabit yatak yük kayıpları ve Ergun denklemi kullanılarak elde edilen küresellik katsayıları tespit edilmiştir. Bu şekilde her malzeme için ayrı ayrı hesaplanan küresellik parametresi akışkanlaşma çalışmalarının modellenmesinde oldukça iyi neticeler vermiştir. Çalışılan malzemelerin küresellik katsayıları kum, perlit, tek seferde kırılarak oluşturulmuş kırık cam ve tekrarlı kırma suretiyle oluşturulmuş kırık cam fraksiyonları için sırasıyla yaklaşık 0.74, 0.66, 0.42 ve 0.55 olarak bulunmuştur. Literatürde sıklıkla atıf alan küresel olmayan malzemelerin akışkanlaşma sırasındaki hız-gözeneklilik ilişkisini veren Dharmarajah-Cleasby (1986) denklemi bu çalışmada elde edilen deneysel veriler kullanılarak irdelenmiş ve küresel ve küresel olmayan malzemelerin genişlemiş yatak yükseklikleri ve gözenekliliklerinin tahmininde kullanılacak alternatif yeni bir denklem ile karşılaştırılmıştır. Geliştirilen yeni modelin Dharmarajah-Cleasby (1986) denklemine göre çok daha tutarlı sonuçlar verdiği görülmüştür. Anahtar Kelimeler: Filtre geri yıkama hidroliği, akışkanlaşma, fitre malzemesi, küresellik.  
A new modification method for triglyceride homopolymerization
Get PDFYağlar bitki ve hayvanların içyapılarında oluşan, suda çözünmeyen ve ana komponenti trigliseridler olan doğal maddelerdir. Yapısal olarak trigliseridler, bir gliserol molekülünün üç yağ asidi molekülü ile oluşturduğu kondenzasyon ürünüdür. Boya endüstrisinde kullanılan, doymamış yağ asidi içeriği fazla olan keten yağı ve ayçiçek yağı gibi kuruyan ve yarı kuruyan yağlar zayıf film özelliklerine sahiptir. Yüzey kaplama uygulamalarında doğrudan olarak kullanılamayan bu yağlar alkaliye, aside, suya dayanıklılık ve yapışma gibi bazı özelliklerinin geliştirilmesiyle yüzey kaplama uygulamalarına elverişli hale getirilebilirler. Yağların homopolimerizasyon veya uygun vinil monomerleri ile kopolimerizasyonları sonucunda yüzey kaplama malzemesi olarak kullanılabilir hale dönüştürülürler. İyi film özelliklerine sahip bir organik yüzey kaplayıcı üretmek için bitkisel yağlarla yapılan kopolimerizasyon reaksiyonlarında en yaygın kullanılan monomer stirendir. Bu çalışmada, yarı kuruyan bitkisel yağların polimerizasyonu yeni bir yöntem ile yapılmıştır. İlk olarak bitkisel ayçiçek yağı belli bir oranda gliserin ile reaksiyona sokularak kısmi gliserid karışımı elde edilmiştir. Daha sonra elde edilen bu kısmi gliserid karışımı ile toluen diizosiyanat ve 2-hidroksietil metakrilat’ın reaksiyona girmesi sağlanarak makromer üretilmiştir. Bu makromerin yapısı FTIR ve GPC analizleri ile tespit edilmiştir. Elde edilen makromerin polimerizasyon ürünü elde edilmiş ve film özellikleri belirlenmiştir. Yapılan analizler sonucunda, bu ürünün film özellikleri açısından kaplama malzemesi olarak kullanılabilecek nitelikte olduğu anlaşılmıştır. Anahtar Kelimeler: Modifiye yağlar, makromer, homopolimerizasyon, trigliseridler.Oils are the natural substances, unsoluble in water, found in the inner structures of the plants and animals and whose main component is triglycerides. The fatty acids contribute from 94-96% of the total weight of one molecule triglyceride oil. Among the triglyceride oils, linseed, sunflower, castor, soybean, oiticica, palm, tall and rapseed oils are commonly used for synthesis of oil-modified polymers. Although fatty acid pattern varies between crops, growth conditions, seasons, and purification methods, each of triglyceride oils has special fatty acid distribution. Linseed oil, for example, consists of largely linoleic and linolenic acids. In castor oil, the greater part of fatty acids is ricinoleic acid (12-hydroxy-9-octadecenoic acid).Depending on the fatty acid distribution, each type of oil has specific physical and chemical properties. One of the most dominant parameter affecting of fatty acid and oil properties is the degree of unsaturation. The average degree of unsaturation is measured by iodine value. It is calculated from the amount of iodine (mg) reacted with double bondsfor 100 g sample under specified conditions. Triglyceride oils are divided into three groups depending on their iodine values; drying, semi-drying and nondrying oils. The iodine value of a drying oil is higher than 130. This value is between 90 and 130 for semidrying oils. If the iodine value is smaller than 90, oil is called non-drying oil. Since triglyceride oils vary widely in their physical properties depending on fatty acids in their structure, the choice of triglyceride oil plays an important role on polymer properties. Linseed oil, for example, is commonly used for the preparation of paint binder, because it consists of reactive unsaturated fatty acids curing with atmospheric oxidation. Castor oil is an important reactant for interpenetrating polymer networks (IPNs) because it contains hydroxyl groups capable of reacting with isocyanate and carboxyl groups. It is possible to select fatty acid distribution function of oils via computer simulation and the molecular connectivity in order to produce linear branched, or cross-linked polymers. Materials prepared by this way can be used to produce pressure-sensitive adhesives, elastomers, rubbers and composites. The most widely used method to characterize material is infrared spectroscopy, particularly Fourier transform infrared (FTIR) spectroscopy. It can also be used for the structural analysis of oils. Nuclear magnetic resonance (NMR) spectroscopy is another important technique for the descriptions of the chemical microstructure of an organic material. It is possible to calculate the fatty acid content of triglyceride oil from NMR data. The calculation of the surfaces of the peaks corresponding to the methylene groups, for example, gave an assessment of the linoleic acid content. Gas chromatography is also widely used for the determination of fatty acid composition of the oils. Triglyceride oils are widely used in the production of organic coating materials. Although oils can not be directly used as surface coatings, after a number of modifications they can be used for surface coating applications because of having much more properties such, drying time, resistance to alkali, acid, water and adhesion. In order to obtain better film properties in coating applications, oils are modified with various methods. Among these methods homopolymerization and copolymerization of oils with vinyl monomers occupies an important place, styrene being the most widely used monomer. In the classical styrenation process, homopolystyrene formation is likely to occur and the presence of homopolymer leads to poor film properties. By taking this fact into account, the methods by which homopolymerization was minimized and polymer structure was controlled, were previously developed in our laboratory. In this study, by using homopolymerization method, it is purposed to produce polymer modified with triglyceride oils obtained from sunflower oil. For this reason, oil has been reacted first with glycerol and obtained partial glyceride mixture. In order to prepare oil based macromonomer, partial glyceride and 2-hydroxyethyl methacrylate (HEMA) were combined through urethane linkage by the reaction with Toluene diisocyanate (TDI). The characteristic properties of the macromonomer such as molecular weight, polydispersity and molecular structure were determined by Gel Permeation Chromatography (GPC) and Fourier Transform Infrared (FTIR) analysis. The resulting macromonomer subjected to polymerization and the corresponding homopolymer were prepared. Film properties of the resulting sample was determined according ASTM and DIN standards as well. The polymer sample showed good alkali and water resistance and good adhesion and flexibility. Keywords: Modified triglyceride, macromer, homopolymerization, triglyceride oil
Capacity acquisition and task allocation with tax-band pricing in telecom networks
Get PDFBu çalışmada bir şirketin, birden fazla tedarikçiden ağ kapasitesi kiralarken karşılaşılacağı eniyileme problemi incelenmiştir. Problem ele alınırken, bir firmanın veri ağları üzerinde gerçekleştirebileceği işler sabit zamanlı ve sabit boyutlu işler olmak üzere başlıca iki kategoriye ayrılmıştır. Bu iki kategorideki işlerin ihtiyaç duydukları zaman ve bant genişlikleri ile kalite gereksinimleri oldukça farklıdır. Bu nedenle çalışmada; farklı fiyat, kalite ve görev dağılımlarının firmaların optimal davranışını nasıl etkilediği analiz edilmiştir. Problemin karmaşıklığını biraz olsun azaltmak amacıyla, kaynak ve talep hazır olduğu sürece, kapasite için bir üst limit bulunmadığı ve kapasitenin limitsiz olduğu varsayılmıştır. Firmaların bu maliyet en küçültme problemi modellenirken, Courcoubetis ve diğerlerinin (2000a) önerdiği her bir tedarikçinin doğru parçalarından oluşan dışbükey doğrusal amaç fonksiyonuna sahip olduğu kademeli (tax-band) fiyatlandırma politikası dikkate alınmış ve amaç fonksiyonu iki tür maliyeti yansıtacak şekilde oluşturulmuştur. Bu maliyetlerden ilki, tedarikçilerin farklı fiyat seviyelerini yansıtan satın alma maliyetidir. İkinci maliyet ise, son teslim tarihlerinin kaçırılması veya vadelerin geçirilmesi, kalitenin düşmesinden kaynaklanan maliyetler ve karar merci bilinçli olarak hizmet niteliği düzeyini düşürdüğünde veya başka bir tedarikçiye yöneldiğinde meydana gelen hizmet niteliği değişim maliyeti gibi olası fırsat maliyetleridir. Ayrıca, gevşetilmiş problemin çözümünde daha iyi bir alt sınır elde etmek için Genelleştirilmiş Bender Ayrıştırma (Generalized Bender’s Decompomposition – GBD) algoritması uygulanmıştır. Anahtar Kelimeler: Telekomünikasyon ağları, hizmet niteliği, kademeli (tax-band) fiyatlandırma.Usage of data networks encompasses not only the traditional data applications but also newer applications such as real-time audio/video streaming, voice over TCP/IP, real-time transactions, asynchronous messaging and other batch transactions over digital networks. Each application has different capacity and quality of service (QoS) requirements. Each is affected differently by network reliability and speed. Major network providers have already started efforts to accommodate the QoS demand generated by these applications. Providers charge differently for the capacity they sell. For example, Internet service providers (ISPs) offer a combination of fixed price for a fixed maximum bandwidth (all-you-can-send) or pay per hour (or minute) for again a maximum bandwidth. Wireless phone companies charge for text messaging based on bytes sent. Certain calling plans offer different per minute charges for phone conversations depending on when the call is placed. A firm uses data networks to perform and support business operations, which we will call tasks. For example, a videoconference is a type of task, so is a remote web site update. The obvious commonality is that both tasks require network resources. A network resource is characterized by its capacity (bandwidth and duration) and QoS. We assume that the contract signed between the firm and the provider specifies the amount of bandwidth and quality guaranteed at a given time. Duration specifies the period during which the resource is available. There are two types of costs associated with using data networks. The first one is the resource (i.e., bandwidth, capacity) acquisition cost. The second is the opportunity cost incurred due to insufficient quality realized in performing certain tasks such as video conferencing. Given a heterogeneous set of tasks and resources that differ in bandwidth and quality requirements, it might be in the firm's best interest to use either multiple providers or sign multiple contracts with different bandwidth and quality requirements. For example, while resources with lower quality can be used for data applications, more expensive resources might be utilized for real-time applications with high QoS requirements. Therefore, the problem that the firm has to solve is a cost minimization problem that reflects a trade off between the cost of acquiring resources and the opportunity cost of degradation in realized quality of tasks performed. The quality of service of the resource affects the customer in two ways. First, size-fixed tasks might be delayed beyond acceptable deadlines. Second, the realized quality of a time-fixed task such as a videoconference might be unacceptable creating an opportunity cost for the customer. In general, opportunity cost reflects the importance of a task. The more important the task is, the higher the penalty for not achieving desired targets (such as audio or visual quality). The decision maker will minimize the total cost by considering the trade-off among these costs when assigning tasks to resources. In our study we formulate a cost minimization problem subject to QoS and capacity constraints. We consider the tax-band pricing scheme suggested by Courcoubetis et al. (2000a) in which each supplier has a convex piecewise-linear cost function for each resource offered. Courcoubetis et al. (2000a) claim that tax-band pricing reduces bursty traffic since customers are likely to reduce such demand to avoid paying more. Suppliers in general would prefer having more customers with less capacity demand rather than fewer customers with high capacity demand. Given this pricing structure the customer has to decide how much capacity to acquire and how to allocate tasks. For tractability we relax the due date constraints and assume that all tasks and resources are available at time zero. We also assume that real-time applications have desired transmission rates and any deviation from that creates an opportunity cost for the customer. In spirit, this is the same objective function used in Kasap et al. (2007) that trades the quality cost with the capacity cost but the cost structure for capacity is quite different in this problem. In this study, firstly, we present tax-band pricing. Secondly, a formulation and a solution procedure based on GBD are described. Keywords: Telecommunication networks, quality of service (QoS), tax-band pricing
Pre-Loaded high strength bolted connections of aluminium members with steel members
Get PDFBu araştırmada alüminyum ve çelik iki farklı malzemenin öngerilmeli yüksek mukavemetli bulonla sürtünme ile yük aktaran birleşimi incelenmiştir. Sürtünme ile yük aktaran birleşimlerin davranışını belirlemek amacı ile, iki farklı grup deney gerçekleştirilmiştir. Bunlar, kısa süreli ve uzun süreli kayma deneyleridir. Kısa süreli kayma deneyleri ile öngerilmeli yüksek mukavemetli bulonlu birleşimlerde, hem alüminyum ve hem de galvanizli çelik temas yüzeylerine herhangi bir işlem yapılmadan sadece yüzeyler yağdan arındırılmış durum için ve alkali silikat çinko boya ile boyanmış durum için, sürtünme katsayısı belirlenmiştir. Yukarıda belirtilen iki farklı temas yüzeyi haline ait yük-yer değiştirme diyagramları, kayma yükü ve sonrasında kopma haline kadar incelenmiştir. Deney sırasında yük altında bulonlardaki öngerilme kuvvetindeki değişim araştırılmıştır. Kısa süreli deneylerde sürtünme yüzeylerine boya kullanılmaması durumunda birleşimler ekonomik olmaktan uzaktır. Sürtünme arttırıcı alkali silikat çinko boya kullanılması durumunda bir bulonun sürtünme ile taşıyabileceği kuvvet yaklaşık olarak 3.5 kat daha fazladır. Yapılan ondört adet kısa süreli deneyden elde edilen verilerden yararlanılarak uzun süreli deney sistemi hazırlanmış ve toplam onbeş adet uzun süreli birleşim numunesi bir yıl boyunca üç farklı çerçevede 90 kN, 78 kN ve 60 kN’luk sürekli yük altında gözlenmiştir. Bu deney sonuçlarının irdelenmesinde daha önce literatürde rastlanmayan sabit aralıklı ayrıklaştırma uygulanmak suretiyle elli yılsonundaki davranış tahmin edilmeye çalışılmıştır. Bu araştırma ile alüminyum ve çelikten oluşan farklı iki malzemenin birleşimi için alkali silikat çinko boyanın kullanılabileceği ve sürtünme katsayısını arttırdığı gösterilmiştir. Anahtar Kelimeler: Birleşim, öngerilmeli yüksek mukavemetli bulon, alüminyum elemanlar.A certain amount of research and studies has been done on the connections of the same kind of material such as aluminum to aluminum or steel to steel connections. However, as far as the connections of two different materials are concerned, there are no systematic works on the subject. In order to connect hot dip galvanized steel material with aluminum material, it is necessary to use high strength pre-loaded bolts. The use of weld is not possible because of the different properties of materials. The presented work is the result of the studies conducted on two different materials- aluminium and steel and their friction grip pre-loaded high strength bolted connections. For this reason, two different types of experiments have been done. These tests are the short-term and the long-term tests, performed on four different dimensions of thickness: 10.0 mm, 9.7 mm, 8.0 mm and 5.0 mm, and on three different aluminum alloys: AlMgSi1 (6082), AlMgSi0.5 (6063) and AlZn4.5Mg1 (7020). In each specimen two 10.9 M16 bolts have been used. In the first five tests of the short-term tests, friction surfaces are only treated oil-free and in the latter 9 test specimens are painted with alkali silicate zinc. In pre-loaded high strength bolted connections, the friction coefficient had been determined for the aluminum and steel specimens with oil-free contact surfaces and also for the alkali silicate zinc painted contact surfaces. For the above mentioned two different cases of treatment of the contact surface, loading-displacement diagrams are studied for shear loads and after it then, up to the occurrence of the rupture. After having subjected the bolts to pre-loading, the loss of pre-load had been studied for 30 min. prior to the beginning of the test. During the test under load, the specimen was monitored to determine whether a sudden loss in pre-load occurred. In the short-term tests after applying the pre-loading to the bolts, no big loss on the pre-load was noticed, because of the creep behavior of aluminum in time. In the short-term tests, when no paint on the friction surfaces was used, the number of the bolts necessary for the proper connections would be too high to be considered economical. In case of using the friction-increasing alkali silicate zinc paint, the limit friction force of one bolt increases 3.5 times. A change of the thickness has no effect on the friction coefficient in short-term tests. When the aluminum alloy has lower yield stress than the steel, an indent under the washer will be observed. This observation is valid only for the AlMgSi0.5 (6063) alloy. That's why it is necessary to transfer the pre-load to a greater surface. To prevent the indent from happening, a thicker and wider washer could be used. After evaluating the short-term test results statistically, it has been noticed that the standard deviation of the distribution of friction coefficient does not exceed 10% limit. With the help of the results of fourteen short-term tests that were conducted, a long-term testing system was prepared and a total of fifteen long-term connection specimens in three different frames with 90 kN, 78 kN and 60 kN of continuous loading was monitored. The loading on each frame was determined so that the friction surface of each specimen was loaded with 75%, 65% and 50% ratios. To prepare the friction surfaces of long-term test specimens, all surfaces were treated with alkali silicate zinc paint. The long-term test had been carried out within one - year time span, during which the loading of each frame, the pre-loading on bolts and the slip between aluminum and steel plates were observed. The effect of small thickness on friction in the long-term tests causes the slip of contact surfaces in time. By using thinner aluminum plates, contact pressure was distributed on a smaller area of contact surface. This explains the earlier shear observed in the long-term tests under constant tension force. The thinner the specimen, the earlier the slip occurs. For the study of the long-term test results using constant distance separation - a method not found in the literature, an attempt has been made to predict the behavior of specimens within 50 years onwards. Inspecting of the 10 mm thick aluminum plate specimens after the period of one year shows that the predicted displacement in 50 years' time will be within the 0.30 mm slip limit range. The conclusion can be drawn that the alkali silicate zinc paint increases the friction coefficient of connections made of two different materials- aluminum and steel. Keywords: Connections, high strength bolts, aluminum members
A model proposal for evaluating manufacturing performance
Get PDFGlobal rekabetin artışı, değişen ve yeni ortaya çıkan pazarlar, kısalan ürün yaşam eğrileri ve imalat teknolojilerindeki gelişmeler, imalat firmalarını karmaşık ve belirsiz bir çevre içerisinde rekabet etmek zorunda bırakmıştır. İmalat firmaları, içinde bulundukları bu dinamik çevrede rekabet edebilir olmak, rekabetçi konumlarını koruyabilmek ve işletme performanslarını arttırmak için rekabet stratejilerini, operasyon, süreç ve prosedürlerini sürekli olarak gözden geçirmek, yeniden tasarlamak ve imalat performanslarını sürekli olarak değerlendirmek zorundadırlar. İmalat performansının değerlendirilmesi, üretim/işlemler yönetimi literatüründe sıkça yer verilen bir konudur. İmalat performansının iyileştirilebilmesi ancak değerlendirilmesi ve içinde bulunulan durumun tespit edilmesi ile mümkündür. Yapılan literatür araştırmasında, imalat performansını değerlendirmede rekabetçi imalat öncelikleri adı verilen unsurların kullanıldığı tespit edilmiştir. Rekabetçi imalat öncelikleri için farklı yazarlar tarafından farklı ölçütlerin önerildiği ya da kullanıldığı görülmüştür. Bu çalışmada öncelikle farklı yazarlar tarafından önerilen farklı imalatçı rekabet önceliklerini bütünsel bir bakış açısı ile ele almak amaçlanmıştır. Ayrıca, literatür incelendiğinde, imalat performansını etkileyen pazar dinamizmi, rekabet stratejisi, stratejik imalat kararları ile imalat performansından etkilenen işletme performansını bütünsel bir bakış açısıyla ele alındığı bir çalışmanın olmadığı tespit edilmiş ve bu nedenle bu eksikliği gidermek amacıyla bu çalışmada imalat performansını etkileyen ve imalat performansından etkilenen bu unsurların bütünsel olarak ele alındığı ve imalat firmalarının imalat performanslarını değerlendirmede kullandıkları rekabetçi imalat önceliklerini açıklayan bir sentez modelin oluşturulması amaçlanmıştır. Anahtar Kelimeler: İmalat performansı, rekabetçi imalat öncelikleri, pazar dinamizmi, rekabet stratejisi, stratejik imalat kararları, işletme performansı.Global competition, shortened product life cycles and developments in manufacturing technologies force manufacturing firms to compete in complex and dynamic markets. In such a competitive and dynamic area, firms have to review and redesign their competition strategies, operations, processes and procedures and evaluate their manufacturing performance in order to be competitive and/or sustain their competitiveness. Needs of customers and firms growing intentions to meet those needs are considered, it turns out to be an undeniable fact that the firms reducing costs, time-to market, and increasing quality and delivery get the highest manufacturing and firm performance. In production and operations research literature, factors used as a means of evaluating manufacturing performance have been called in many different ways such as manufacturing tasks, competitive priorities, order winners and qualifiers, etc. Since the name ?competitive manufacturing priorities? is mostly used in the literature, it is determined to call the factors used in evaluating manufacturing performance as competitive manufacturing priorities in this study. It is also observed that different authors have proposed or used different measures for competitive manufacturing priorities. In this study, the primary aim is to deal with different competitive manufacturing priorities proposed by different authors integrally, and to determine the measures and sub-measures of competitive manufacturing priorities used by manufacturing firms to evaluate their manufacturing performance. By reviewing literature, it is observed that the generally used competitive manufacturing priorities are cost, quality, delivery and flexibility. There are also additional priorities taking place in recent studies. After examining all of the competitive manufacturing priorities used by authors, four commonly used priorities (cost, quality, delivery and flexibility) and four additional manufacturing priorities were decided to use in this study. The additional competitive manufacturing priorities that have vital importance in today's global and dynamic markets in which the manufacturing firms compete are production time, new product development, customer satisfaction, and supplier performance. In literature review, the factors that affect manufacturing performance and that is affected by manufacturing performance were also surveyed. The factors that affect manufacturing performance are market dynamism, competitive strategy, strategic manufacturing decisions and the factor that is affected by manufacturing performance is firm performance. There are only few studies that have dealt with the relationship between these factors and manufacturing performance in an integrated manner is encountered. Therefore, developing a synthesis model that explains the factors that affect manufacturing performance and the factors that are affected by manufacturing performance was determined as another aim of this study. The model composed of three main parts. First part of the model is dealt with the relationship between market dynamism, competitive strategy and strategic manufacturing decisions. Extensive global competition and customer's expectation about rapid introductions of new, high-value, high-quality products make markets more dynamic. In order to compete in such a global and dynamic market, manufacturing firms make, implement and/or revise their strategic manufacturing decisions and set their competitive manufacturing priorities based on their competitive strategy. In the second part the relationship between strategic manufacturing decisions and manufacturing performance was discussed. And the last part of the model is dealt with the relationship between manufacturing performance and firm performance. The measures and sub-measures of market dynamism, competitive strategy, strategic manufacturing decisions and firm performance were also reviewed as well as manufacturing performance. Firm performance has been measured in different ways but the most important measurement of firm performance is the financial dimension. Therefore measures of firm performance used in this study are financial performance measures. In this study, concepts related with manufacturing performance are discussed. Primary object of the study is delineating dimensions of manufacturing performance. Second contribution of the study is satisfying a need for a synthesis model covering both the factors that affect manufacturing performance and the factor that is affected by manufacturing performance. Accordance to these aims the study is structured in the following way. Firstly, the competitive manufacturing priorities which are used for evaluating manufacturing performance are defined in details. Later, the factors that affect manufacturing performance including market dynamism, competitive strategy, strategic manufacturing decisions and the factor that is affected by manufacturing performance firm performance were discussed. Finally, a synthesis model dealing with the relationship between market dynamism, competitive strategy, strategic manufacturing decisions, manufacturing performance and firm performance was conducted. Keywords: Manufacturing performance, competitive manufacturing priorities, market dynamism, competition strategy, strategic manufacturing decisions, firm performance
Alüminyum köpük üretiminde alaşım elementlerinin etkisi
Get PDFDuring the last ten years, the subgroup of functional materials, foams are coming forth with their combined features such as light weight, high specific strength, large surface area and high absorbing capabilities. These structures consist of two branches: open cell foams with enormous surface area enabling fluids to flow through and closed cell foams having the ability of absorbing various kinds of energies (sound energy, impact energy, magnetic energy, vibration energy, radiation). Closed cell aluminum foams are largely investigated metal foams because of base metal’s advantages like low density, low melting point, low cost, recyclability and being incorporated by several kind of alloys. As for the closed cell aluminum, pores have to be generated usually by gases, either introducing the gas into the melt or creating a gas pressure inside the semi-molten compact. The latter is also referred as powder route production, where metallic hydrides or carbonates act as foaming agents releasing gases into the compressed precursor by decomposing in certain temperatures. In literature, mostly titanium hydride (TiH2) is preferred as the foaming agent due to its high decomposition temperature. Also heat treating to titanium hydride can even delay the decomposition temperature. Thus, it enables proper foaming without cracks. As the nature of the structural material, 6000 series alloys are of special interest due to their heat treatable nature and positive effects on foaming. In this research, three factors, Mg, Si and TiH2 at three levels are examined according to the designed experimental plan. The three levels of Mg and Si are 0.5-1-1.5% (wt) and 0.4-0.6-0.8% (wt) for TiH2. Response surface methodology is used to analyse the effects of these factors on foaming and these effects are demonstrated on the selected response: micro hardness. The aim of this work is to evaluate the effects of the factors determined in the designed experimental plan and to realize the alloying during foaming. In the total of 16 experiments, powder compositions are varied while the other conditions are held constant for the sake of meaningfullness of the results. Briefly, each powder composition are weighed as accurate as possible with a high precision balance that can recognize 0.0001th of a gram, then mixed separately for half an hour and finally they are compacted with uniaxial press to get the closest theoretical density value (least 99.5% is reached for any precursor is achieved). The theoretical density of the precursıor’s are tested by Archimedes’ Principle. Lastly, precursors are foamed in an atmospheric furnace at 715° for 12 minutes. Then the foaming mold is placed on a copper plate which is continuosly cooled with water to solidify the all body as soon as possible. The so called importance of theoretical density comes from the necessity of imprisoning the foaming gas within the precursor. It is important when the released gas is H2 with low molecular diameter which can easily escape from any cracks or holes. Also the decomposition temperature of TiH2 (~400°C) when compared to metal’s melting point (~660°C) can cause release of the gas which is an issue because the decomposition takes place in solid phase makes difficult to keep the gas inside the precursor. Another point to be stressed in this study is alloying that is expected to happen during the foaming process without applying any pre-alloying procedure. To investigate that, responces are analysed with statistical tools and microstructure of the foams are investigated. Produced aluminum foams are cut into half to obtain micrographs with optical microscope (OM) and scanning electron microscope (SEM), and also to run microhardness tests. Statistical analysis (ANOVA and Regression) show quite good correlations (R2 and R2 adjusted being 89.3% and 86.28%) between mesaured microhardness values and calculated ones. It is found that silicon has a parabolic effect on microhardness where magnesium rises the hardness in a linear manner. 1.5 % Mg and 1.5% Si is the foam that gives the hardest composition. As expected, the foaming agent, TiH2, does not show significant effect on the microhardness. Microstructural characterizations show that powders are sintered and formed grains. And, plate like b-AlFeSi phases have formed at the grain boundaries. No Mg2Si phase is detected since the foams underwent no heat treatment procedure. Consequently, all these statistical and microstructural analysis reveals that alloying during foaming is achieved in the coherence with literature. Keywords: Aluminum Foam, Response Surface Analysis, 6000 series aluminum alloys.Kapalı hücreli metal/metalik köpükler arasında alüminyum köpükler düşük yoğunlukları, ısıl işlemle mekanik özelliklerinin geliştirilebilmesi, sesi, titreşimi, radyasyonu, darbe enerjisini ve manyetik enerjiyi sönümleme yetenekleri ve düşük maliyetle üretilmeleri nedeniyle teknolojik uygulamalara yatkın fonksiyonel malzemeler olarak ön plana çıkmaktadır. Bu çalışmada, kapalı hücreli alüminyum köpük üretiminde alaşım elementlerinin ve köpükleştirici oranının köpükleşme mekanizmasına etkisi yanıt yüzey analizi yöntemi ile irdelenmiştir. Alüminyum tozuna magnezyum ve silisyum alaşım elementleri toz olarak ilave edilmiş ve 6000 serisi yaşlandırılabilen alüminyum alaşımı köpük halinde üretilmiştir. Köpükleştirici ajan olarak titanyum hidrür kullanılmıştır. Tozlar herhangi bir alaşımlandırma işlemine tabi tutulmaksızın karıştırılıp hazırlanmış ve 450°C’de sıcak preslenerek köpükleşmeye hazır kompaktlar haline getirilmiştir. Köpükleştirme 715°C’de atmosferik ortamda ve 12 dakika süre ile yürütülmüştür. Elde edilen alüminyum köpüklerin sertlikleri ölçülmüş ve sonuçlar ANOVA ve regresyon analizleri kullanılarak istatistiki olarak değerlendirilmiştir. Deneyler sonucunda başlangıç malzemesi olarak saf elementer tozlar kullanılarak alaşımlı alüminyum köpük üretilmiş ve üretilen köpüklerin sertliği üzerinde kullanılan köpükleştici ajanın etkisi olmadığı ancak magnezyum yüzdesi arttıkça sertliğin lineer olarak arttığı, silisyum yüzdesi arttıkça ise sertliğin parabolik bir eğilimle değiştiği görülmüştür. Saf elementer tozlardan elde edilen köpüklerin mikroyapı çalışmalarında oluşan fazların morfolojileri optik mikroskop ve taramalı elektron mikroskobu ile karakterize edilmiş ve tane sınırlarında yoğunlaşmış çubuksu fazlara rastlanmıştır. Bu fazların kimyasal analizi sonucunda b-AlFeSi olduğu tespit edimiştir. Anahtar Kelimeler: Alüminyum Köpük, Yanıt Yüzey Analizi, 6000 serisi alüminyum alaşımları
The ratio and structure relationship in Lüleburgaz Sokollu Mehmed Paşa Mosque
Get PDF16. yüzyıl boyunca Mimar Sinan ekolünün ortaya koyduğu anıtsal cami yapılarında uygulanan ana plan şemaları arasında, en önemlilerinden biri karedir. Sinan, Lüleburgaz Sokollu Mehmed Paşa Camii’nde bu kare plan yorumunu, hiç yüzey alanı kaybetmeden ve işlevsel unsurlara hacimsel bütünlük içinde algılanabilen ölçüler vererek uygulamıştır. İç mekanda, kubbeyi taşıyan derin kemerler altında oluşan hacimler, iki katlı mahfil düzenlemesiyle orta mekanla bütünleşmekte ve dört köşede yer alan payeleri üst bitimlerinde birbirlerine bağlayarak ana strüktüre doğrudan katılmaktadırlar. Böyle bir yorumun, başkentten uzak bir menzil külliyesinin en önemli yapısı olan bu camide, İstanbul’daki anıtsal mimari örneklerde olduğu gibi, aynı titizlikle uygulanması, Lüleburgaz Sokollu Mehmed Paşa Camii’nin önemini ortaya koymaktadır.The square plan is one of the most important main forms among the diagrams that were applied in monumental mosque structures laid by Mimar Sinan style during the sixteenth century. Sinan’s interpretation of square plan at Lüleburgaz Sokollu Mehmed Paşa mosque was applied without losing any surface area and he used all functional elements within the boundaries of perceptible measures. In interior space, the spaces constituted under the thick arches are connected to the middle space via the double-storey gallery design. These galleries connect the top endpoints of the piers located on all four corners. By this way, the galleries become direct members of the main structure. In exterior space, the static problem is solved by upper structure elements. High arches on all four directions are bordered by cornices with profiles, reflected on the frontages as stepped frontals, and elevated to the tambour. Viewing the structure on a whole, strong piers on all corners are not perceived in the interior space with their grand mass; however, on the exterior space, they are expressed as load towers covered with little cupolas that are built on a polygon-based plan. The sensitive application of this interpretation to this structure, which is an important part of a complex that is far from the capital, brings the significance of Lüleburgaz Sokollu Mehmed Paşa mosque into light
Relation of the house preferences with space syntax parameters
Get PDFEvler kendi iç düzenlerinden, oluşturdukları şehir ölçeğindeki çevrelere kadar, insan yaşamını, insan davranışlarını ve toplum düzenini etkileyecek güce sahiptir. Makale konut kullanıcısının kendi davranışları ile mekanın dizinsel verileri arasındaki ilişkinin varlığını ve niteliğini araştırmayı hedeflemektedir. Konut kullanıcılarının mekansal davranışları ve konutun mekansal dizin özellikleri arasındaki ilişkilerin, konut tercihlerini etkilediği hipotezini desteklemek üzere çeşitli ölçütler belirlenmiştir. Bu ölçütler konut kullanıcılarının sosyodemografik özellikleri, yaşam biçimleri ve konuta ait mekansal özellikleridir. Bu makalede konutların kullanıcılarının yaşam biçimi, sosyal statüsü ve mekansal tercihleri arasındaki ilişkileri yansıttığı; diğer yandan, kullanıcıların da konutun olanaklarına ya da kısıtlamalarına uyum sağladığı ortaya koyulmuştur.Houses can form spaces in various scales, which are consequently capable of affecting human behaviour and communal organizations. The paper aims to examine the existence and quality of relations between the behavioural inclinations of the user and the spatial syntax of the house. Space syntax is a theory and a mathematical based method that generates different spatial arrangements, in order to define the structural environment. The essential concept of syntactic approach assumes that the interior and exterior forms of spaces are shaped according to certain cultural considerations and these forms also affect social relations. In order to support the hypothesis, which indicates that the relations between the user's spatial behaviours and the syntactic properties of the space affects to the house preferences, there were some criteria determined through a two staged case study performed in Atasehir Satellite City, Istanbul. These critera are the sociodemographic characteristics of the users, life styles of the users and the syntactic characteristics of the house. The results of the case study provide data about the socio demographic background of the users, their life styles and spatial preference, living room usage and furniture grouping, which were substantially converted to numerical database in order to be analysed by "Georgia Institute of Technology" licensed "Spatialist" software. In this paper it is exposed that the houses reflect and demonstrate the relationship between parameters such the social status, life style and the spatial preferences of the occupiers. On the other hand, the occupiers also adjust to the possibilities or restrictions provided by the houses
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