Discrete H? model matching problem by dynamic state feedback

Bu çalışmada bir ön kontrolörün eşdeğeri olan dinamik durum geribeslemesi ile ayrık H¥ model eşleme probleminin doğrusal matris eşitsizlikleri yaklaşımı ile çözümü amaçlanmıştır. Ayrık H¥ model eşleme problemi, ayrık H¥  optimal kontrol probleminin özel bir halidir. Bu nedenle ayrık H¥ optimal kontrol probleminin doğrusal matris eşitsizlikleri ile elde edilen çözümü ayrık H¥ model eşleme probleminin çözülmesi için kullanılabilir. Makalede ayrık H¥ model eşleme probleminin dinamik durum geribeslemesi ile çözümünün tek doğrusal matris eşitsizliğine  indirgenebildiği gösterilmiş ve kontrolör tasarımı için gereken sentez teoremi ve algoritma verilmiştir.Anahtar Kelimeler: H¥ kontrol, H¥ model eşleme problemi, doğrusal matris eşitsizlikleri.The model matching problem is one of the most familiar problems in the control theory. Let Tm(z) and T(z) be stable and proper transfer matrices. The discrete H¥ model matching problem is to find a controller transfer matrix R(z) which is stable and causal, to minimize the H¥ norm of Tm(z)-T(z)R(z). The interpretation is this: Tm(z) and T(z) are given as the model and the given system transfer matrices, respectively. Thus, the closed-loop performance T(z)R(z) approximates the desired performance Tm(z). In this paper, we consider the discrete H¥ model matching problem with dynamic state feedback in the sense of H¥ optimality criterion by using linear matrix inequalities approach. The main contribution could briefly be explained as to reformulate the discrete H¥ model matching problem as a special discrete H¥ optimal control problem in the formulation of linear matrix inequality, to derive a solvability condition for this special case and to give a design procedure for the controller of the discrete H¥ model matching problem. It may be noted that the linear matrix inequality based parameterization of the controller provides the best performance of the discrete H¥ model matching problem in the sense of H¥ and the controller can be determined through the solution of only one linear matrix inequality. Keywords: H¥ control, H¥ model matching problem, linear matrix inequalities

The Reflection of Production on Space in Gaziantep Traditional Housing in the Context of the Relationship Between Housing and Culture

Konut ve barınma olgusu, insan varlığının en belirgin temsili olarak, tarihsel, sosyal, kültürel odaklı pek çok çalışmanın konusu olmuştur. Konutu, kültür zemininde merkezine alan çalışmaların ilgisi, konut mekânın bir kültür bileşeni olmasına, maddi ve manevi kültürel değerlerin mekânda vücut bulmasına bağlanabilir. Bu çalışmada ise konutun kültürle ilişkisi, geleneksel konutun mekânsal özelliklerinin geleneksel üretimle olan ilişkisi bağlamında ele alınmıştır. Çalışma, geleneksel Gaziantep evi aracılığıyla, geleneksel yaşam kültürünün konut mekânının biçimlenişine etkisini, üretim ve mekân ilişkisi yardımıyla değerlendirmeyi amaçlamıştır. Gaziantep’in oldukça zengin, çeşitliliğiyle dikkat çeken, hemşerilik bilinciyle korunan ve sürdürülmeye çalışılan kültürel değerleri, kentin çalışma alanı olarak seçilmesinde etken olmuştur. Kentin geçmişinde tarıma dayalı üretimle birlikte çeşitli el sanatlarının ve dokumacılık üretiminin geliştiği ve ticaretinin yaygınlaştığı bilgisinden hareketle özellikle tarımsal ve el sanatlarına dair üretimin geleneksel konut mekânındaki izleri aranmaya ve konut kullanımındaki etkisi belirlenmeye çalışılmıştır. Böylece geleneksel konutun bir üretim mekânı olarak tartışılması ve üretim kültürünün konut mekânının biçimlenişine etkisinin sorgulanması hedef- lenmiştir. Belirlenen amaç doğrultusunda öncelikle kültür kavramına, konut ve kültür ilişkisine değinilmiş ve Gaziantep kentinin tarihçesine yer verilmiştir. Ardından Gaziantep evinin üretimle olan ilişkisini değerlendir- mek maksadıyla, yörenin geleneksel üretim unsurları tespit edilmiş, el sanatları ustalarıyla sözlü görüşmeler yapılmış, seçilen geleneksel konut örneklerinde yapılan yerinde tespit ve gözlem çalışmalarıyla geleneksel üretime dair izler, unsurlar ve alanlar belirlenmeye çalışılmıştır. Tespit çalışmasında geleneksel üretimin mekanla ilişkisini anlayabilmek için konutta kullanım alanları konut içi ve konut dışı mekânlar olarak grup- lanmıştır. Bu gruplamaya göre Geleneksel Gaziantep evinde konut içi mekânlar odalar ve livan-eyvan, konut dışı mekânlar ise hayat, mutfak-ocaklık, mağara-kiler-hazna olarak ayrılmıştır. Ulaşılan sonuçlar, geleneksel Gaziantep evinin, çok katmanlı ve çok fonksiyonlu mekân kullanımıyla, Türk evinin karakteristik özellikleri- ne sahip olduğunu göstermektedir. Yanı sıra Türk evinde sürdürülen ataerkil aile yaşantısının izleri Gaziantep geleneksel evinde belirgin biçimde izlenebilmektedir. Çalışmada, Geleneksel Gaziantep evinin bir üretim mekânı olduğu, günümüzde fabrikalarda gerçekleştirilen üretimlerin bir bölümünün geleneksel konutta ger- çekleştirildiği, bunlara ek olarak üretimin niteliğine bağlı olmakla birlikte, konutun hemen hemen tüm mekân- larının, geleneksel üretimin bir aşamasında etkin rol aldığı sonucuna varılmıştır. Ayrıca üretimde kullanılan tabaka, sal teknesi, gane gibi mekân bileşenlerinin ve dokuma tezgâhı gibi donatıların da konut alanlarında yer aldığı belirlenmiştir. Sonuçlar, evin geleneksel yaşamın bir uzantısı olduğunu, evin bir barınak, bir dinlenme ve güne hazırlık mekânı olmanın ötesinde, yaşantının kendisini barındırdığı, kışı geçirmek için gıdanın üretil- diği, sermek için kilimin örüldüğü, giyilmek için kumaşın dokunduğu, misafirin ağırlandığı, düğün ve eğlen- cenin yapıldığı yer olduğunu işaret etmektedir. Bu açıdan geleneksel konutun, yaşam kültürünün bir yansıma- sı olduğu, yaşantının gerektirdiği ihtiyaçları karşılamak amacıyla üretim mekânı olarak biçimlendiği belirlen- miştir.The phenomenon of housing and accommodation, as the most prominent representation of human exist- ence, has been the subject of many historical, social and cultural-oriented studies. The reason for the interest of the studies that put the housing to its center on the cultural context can be attributed to the fact that the housing space is a cultural component and the material and nonmaterial cultural values come into being in the space. In this study, it is aimed to evaluate the relationship of housing with culture in the context of the rela- tion of spatial characteristics of traditional house with the traditional production. The study aims to examine the effects of the traditional living culture on the formation of the housing space through the relationship between production and space in the scope of traditional Gaziantep house. The rich cultural values of Gazian- tep city are noticing with its' diversity, which are protected and tried to be maintained with the awareness of citizenship, have been a factor in the selection of the city as a research area. Based on the knowledge that various handicrafts and weaving production developed and trade became widespread with agriculture-based production in the past of the city, the traces of agricultural and handicraft production in the traditional housing space were tried to be sought and the effect on housing use was determined. In this manner the traces of traditional life in the city, especially agricultural production and handicraft, in the traditional housing space were searched and the effect on the formation of the housing scheme was tried to be determined. Thus, it is aimed to discuss the traditional house as a production space and the effect of production culture on the for- mation of the housing space. In line with the purposes of the study, the concept of culture and its relationship with housing was mentioned and the history of Gaziantep city was given briefly. In order to evaluate the relationship of the traditional house with production, the traditional production elements of the region were determined, oral interviews with the handicraft masters of the region were made and on-site observations were realized. In the study, the areas in the traditional house are grouped as indoor residential used and outside residential used spaces. According to this grouping, in the traditional Gaziantep house, indoor spaces are divided into rooms and livan-eyvan, and non-residential use spaces are divided into hayat, kitchen-ocaklik, cave-kiler-hazna. The result shows that the traditional Gaziantep house has the characteristics of a Turkish house with its multi-layered and multi-functional use of space. In addition, the traces of the patriarchal family life in the Turkish house can be observed in the traditional Gaziantep house. In addition, it has been deter- mined that spatial components such as tabaka, sal basin, gane, and equipment such as hand loom used in production are also located in the traditional housing space. It has been determined that some of the produc- tions carried out in the factories recently are carried out in the traditional housing in the past, and in this respect almost all spaces of the house take an active role in one of the phases of traditional production. The results revealed that the house is an extension of the traditional life, it is not only a shelter or a place of rest and preparation for the day, but also it is a place where food is produced for the winter times, and the fabric is woven to be worn. It is also a place where the guests are hosted or a wedding and entertainment is held. In this respect, it has been determined that traditional house is a reflection of the living culture, and formed as a production space in order to meet the needs of life

Doğrudan ayrık tasarım ile Hamiltonian sistemlerde bozucu bastırma

In last decades, there are many ongoing researches on the subject of the modelling and control of complex nonlinear systems. The port-controlled Hamiltonian (PCH) approach is an important modeling and control technique which has been proposed for complex nonlinear systems, especially where electrical and mechanical sub-systems have to be considered together. Besides, the disturbance attenuation problem and the design of controllers under parametric and/or structural uncertainties are important issues in practical applications. In the literature, the H approach has been used to solve the disturbance attenuation problem and to provide robust control for nonlinear systems. While the disturbance attenuation problem characterized by means of the so-called L2 gain of a general non-linear system is required to solve the Hamilton-Jacobi-Isaacs (HJI) partial differential inequality, the same problem for Hamiltonian systems can be reduced to solve an algebraic HJI. For this reason, in literature, some nonlinear H control problems for Hamiltonian systems have been defined and some sufficient conditions have been presented to solve the proposed problems. On the other hand, it is well known that nowadays computer-controlled systems using industrial processors are preferred in engineering practice because of the simplicity and flexibility of their implementation. Therefore, it has been gained more importance to develop modeling and control techniques for discrete-time nonlinear systems. In literature, there are several studies on discrete time nonlinear systems, which can be classified, roughly, in two groups. While one group deals with the concepts of the losslessness, the feedback equivalence and the global stabilization of discrete-time non-linear systems, the other group works deriving the discrete-time counterpart of the H control techniques which are developed using the exact model of the system. It should be noted that a direct discrete-time PBC (Passivity Based Control) control method by using an approximate discrete-time Hamiltonian model has been developed by Astolfi and Laila (2005,2006b), recently. In this study, the discrete-time counterpart of disturbance attenuation problem for a class of Hamiltonian systems (n-dof mechanical systems) is investigated and a sufficient condition for the solution of the problem is given To fulfill, firstly a discrete-time equation, which corresponds to the given Hamiltonian system, is derived by a gradient based discrete-time modeling technique. For this purpose an appropriate discrete gradient definition is presented. Afterwards, using this equation, the disturbance attenuation problem characterized by the means of L2 gain is defined and the results are presented as a theorem, which provides a sufficient condition on the existence of the solution of the proposed problem. In order to obtain the discrete-time version of disturbance attenuation problem for the Hamiltonian systems, a term corresponding to the discrete version of the gradient term in the continuous Hamiltonian model is needed. For separable Hamiltonian systems, the discrete gradient defined in this study satisfies both of the discrete-gradient conditions given in (Gonzales, 1996), but it does not satisfy the first condition precisely, for non-separable case. The main results of this study presented as a theorem is derived under the assumption such that, there exists a discrete gradient which satisfies the discrete-gradient conditions exactly. A detailed discussion is also given for the case where the conditions are not precisely satisfied. The given discussion should be taken into account while the condition HJ1in the theorem is used for the design of discrete-time control rule, especially when slow sampling is used. The proposed direct discrete-time design method is utilized to solve the disturbance attenuation problem of the double pendulum system and tested by simulations. The simulation results have demonstrated that the controller obtained using the method developed in this paper has better performance than the emulator controller for sampled data Hamiltonian systems. It should be noted that the computational complexity of the discrete control rule obtained in this is nearly same as the computational complexity of the emulation controller. This property might provide an important advantage especially in industrial applications. Keywords: Hamiltonian Systems, Discrete-gradient, Discrete-time control, H -optimal control, Disturbance Attenuation.Bozucu bastırma problemi pratik uygulamalar için önemli bir konudur. Literatürde, H∞ yaklaşımı hem doğrusal hem de doğrusal olmayan sistemlerin bozucu bastırma probleminin çözümünde kullanılan tekniklerden biridir. Kapı-kontrollü Hamiltonian (PCH, port-controlled Hamiltonian) yaklaşımı ise mekanik ve elektrik alt sistemlerden oluşan karmaşık doğrusal olmayan sistemlerin modellenmesi ve kontrolü için önerilmiş güçlü bir tekniktir. Ayrıca, teknolojinin gelişim yönüne koşut olarak günümüzde mühendislik uygulamalarında bilgisayarlı kontrol sistemleri tercih edildiğinden, ayrık zamanlı doğrusal olmayan sistemler için modelleme ve kontrol yöntemleri geliştirmek önemli olmuştur. Bu çalışmada n-serbestlik dereceli Hamiltonian sistemler için ayrık zamanlı bozucu bastırma problemi ele alınmış ve bir doğrudan ayrık tasarım yöntemi önerilmiştir. Ele alınan problemin çözümüne ilişkin koşulları verebilmek için öncelikle, verilen Hamiltonian sistemin ayrık zamanlı dinamiklerini gradyan temeli bir ayrık zamanlı modelleme yöntemi ile türetmeye olanak sağlayan uygun bir ayrık-gradyan tanımlanmıştır. Ele alınan sistemler için bozucu bastırma problemi ayrık zamanda ifade edilmiş ve bir doğrusal olmayan durum geribesleme kontrol kuralı ile çözümün varlığına ilişkin yeter koşul bir teorem ile verilmiştir. Genel doğrusal olmayan sistemler için kısmı diferansiyel bir HJI (Hamilton-Jacobi-Isaacs) eşitsizliği olan yeter koşul bu çalışmada bir cebirsel HJI eşitsizliği olarak elde edilmiştir. Önerilen doğrudan ayrık tasarım yöntemi çift sarkaç sisteminin bozucu bastırma probleminin çözümünde kullanılmış ve benzetim yoluyla başarımı sınanmıştır. Benzetim sonuçları, bu çalışmada önerilen doğrudan ayrık tasarım ile elde edilen ayrık zamanlı bozucu bastırma kontrol kuralının emulatör kontrol kuralına göre daha yüksek başarıma sahip olduğunu göstermektedir. Ayrıca, önerilen kontrol kuralının hesap karmaşıklığı, emulatör kontrolün karmaşıklığı ile hemen hemen aynıdır. Anahtar Kelimeler: Hamiltonian sistemler, Ayrık-gradyan, Bozucu bastırma

A modeling and realization method for the control of Discrete Event Systems

Sonlu durum makineleri ya da otomatlar, Ayrık Olay Sistemlerinin (AOS) analiz, tasarım ve kontro-lüne yönelik formal yöntemlerin yer aldığı uygulamalarda yaygın olarak kullanılmaktadır. Ayrık olay sistemlerinin geribeslemeli kontrolü için kuramsal bir yapı tanımlayan Üstdenetim Kuramı ve bu kurama ilişkin uygulamalar buna örnek olarak verilebilir. Otomatın standart tanımının, tasarıma ilişkin ayrık olay sistem davranışını ifade edebilmesine rağmen, zamanlama ve sayma gibi bazı davranışları bu modelleme biçimi ile ifade etmek kolay değildir. Bu çalışmanın temel amacı, AOS davranışlarının, özel olarak kontrole yönelik davranış kurallarının tasarımını ve ifadesini mümkün kılan durum tabanlı bir modelleme biçiminin geliştirilmesi ve bu modele dayanarak tasarlanmış davranışın uygulanabilmesi için bir yöntemin elde edilmesidir.  ZS-otomat olarak anılan yeni mo-delleme biçimi, uygulamada sıklıkla karşılaşılan zamanlama ve sayma davranışlarının durum gös-terimi ile ifade edilmesini mümkün kılan Zamanlama ve Sayma Yapısına sahiptir. Modelin önemli bir özelliği, gerçekleme aşamasında kullanılan teknolojik araçlarda doğrudan uygulanabilecek yapısal bileşenler içermesidir. Bu çalışmada, modelleme biçiminin yanı sıra, bir gerçekleme yöntemi de tanıtılmaktadır. Gerçekleme yöntemi, ele alınan bir AOS için tasarlanmış kontrolörün ya da üstdenetleyicinin Programlanabilir Lojik Kontrolörlerle (PLC) gerçeklenmesine yönelik adımları sistematik olarak tanımlamaktadır. Yöntemin, tasarım davranışını yanlış olarak gerçeklemeye neden olan “çığ etkisi” adlı bir problem için çözüm oluşturduğu da gösterilmiştir. Geliştirilen yöntemle, tasarımda öngörülen zamanlama ve sayma davranışları, PLC’lerde kullanılan Zamanlayıcı ve Sayıcı bloklarını doğrudan kullanılmasını mümkün kılmaktadır. Sistematik olarak tanımlanan bu yöntem, programlanarak otomatik kod üretimini mümkün kılan bir yapıdadır.   Anahtar Kelimeler: Ayrık olay sistemleri, gerçekleme, Programlanabilir Lojik Kontrolör.When formal methods are applied in control design of Discrete Event Systems (DES), it becomes necessary to model the system behavior and specifications by a formalism such as automata or Petri nets. For example, the supervisory control theory (SCT) introduced by Ramadge and Wonham in 1987, uses formal languages to model system behavior and, specifications and formal languages are often expressed by automata. The synthesized controllers or supervisors are also represented by automata which are then needed to be realized by a programmable device. Standard definition of the automaton is capable of describing the DES behavior of a design; however some behaviors like timing and counting can not directly or easily be represented in the standard formalism.Implementing a timing mechanism is necessary for discrete event control systems when a certain amount of delay is required to make a decision after an event occurs. A green traffic light, turning on after a certain time period following the red light could be an example. Likewise, a counting mechanism is applied if it is necessary to count the occurrence of a particular event for a number of times before issuing a control signal. For the case of manufacturing systems, packaging the products when a certain number of products are reached could be an example for the requirement of counting mechanism. While it is possible to implement the timing and counting requirements easily with the technological elements, formal definition of the standard automaton does not include such kind of mechanisms. However, it is possible to realize a time delay when utilizing formal methods. It is straightforward to define a time delay by assigning an event to indicate that a predetermined time has elapsed. However, in this case, a timing mechanism is required in the realization stage which is not a part of the formal structure. For counting an event for n times, n successive states in the automaton representation of the supervisor could be used, but in the general case, this may necessitate using large number of states. Therefore, a structure that is capable of representing the timing and counting behavior without using external mechanisms and excessive number of states is required. Another requirement regarding the implementation of formal supervisors is an output mechanism that would issue control signals (enabling or disabling signals for the example of Supervisory Control Theory) or events to drive the DES system being controlled. This requirement is generally met by employing automata with outputs for the representation of the supervisor.When implementing a DES control strategy for discrete event systems, timing and counting behaviors are frequently applied by using predefined objects of the technological device which is used for the realization of control strategy. Programmable Logic Controllers (PLCs) have been used in industrial applications for more than 35 years, and in today's industrial control systems Programmable Logic Controllers (PLCs) are extensively used for realizing control strategies. PLCs make it possible to realize timing and counting behaviors easily by utilizing ready-made objects called timers and counters. In this study, a formalism that enables designing and expressing DES behavior is developed, and a methodology that implements the designed behavior based on the introduced formalism is obtained. The new formalism, named TC-automaton, has a so called Timing and Counting Structure that enables the designer to assign timing and counting behaviors to the state based representation. An output function structure which enables outputting events depending on the states and/or on Timing-Counting Structure of the TC-automaton is also defined. TC-automaton is defined in such a way that, in the realization stage, it is possible to make use of the tools provided by the physical realization platform, i.e. PLCs. The implementation methodology introduced for the new formalism systematically defines the steps for realizing the designed controller or supervisor via PLCs. This systematic setting makes it possible to program the methodology, which is a step toward automatic code generation. It is also shown that, the methodology resolves "avalanche effect" problem, which might be encountered due to a particular structure of the automaton representation of the control behavior. PLC programs obtained by utilizing the methodology are also modular in structure which enhances program readability. Keywords: Discrete Event Systems, realization, Programmable Logic Controllers

Systems approaches to sustainable advancement of developing countries: Recent contributions

Dimirovski, Georgi M. (Dogus Author) -- Conference full title: 17th World Congress, International Federation of Automatic Control, IFAC; Seoul; South Korea; 6 July 2008 through 11 July 2008.Advanced information technologies resulting from automation of control and decision expertise and their respective scientific disciplines have essential impacts on the development of national economies within the more and more globalized economy hence a decisive role in ameliorating current socioeconomic problems in developing countries. Recent developments have put new emphasis on the IFAC activities dedicated to help improving the technological background of developing countries so as to assists their sustainable but accelerated developments. It is important to keep the focus should be on innovative systems approaches to combined knowledge and technology transfer to developing countries that may remedy their current state of the matters

LC-HRMS Profiling and Antidiabetic, Anticholinergic, and Antioxidant Activities of Aerial Parts of Kınkor (Ferulago stellata)

Kınkor (Ferulago stellata) is Turkish medicinal plant species and used in folk medicine against some diseases. As far as we know, the data are not available on the biological activities and chemical composition of this medicinal plant. In this study, the phytochemical composition; some metabolic enzyme inhibition; and antidiabetic, anticholinergic, and antioxidant activities of this plant were assessed. In order to evaluate the antioxidant activity of evaporated ethanolic extract (EEFS) and lyophilized water extract (WEFS) of kınkor (Ferulago stellata), some putative antioxidant methods such as DPPH· scavenging activity, ABTS•+ scavenging activity, ferric ions (Fe3+) reduction method, cupric ions (Cu2+) reducing capacity, and ferrous ions (Fe2+)-binding activities were separately performed. Furthermore, ascorbic acid, BHT, and α-tocopherol were used as the standard compounds. Additionally, the main phenolic compounds that are responsible for antioxidant abilities of ethanol and water extracts of kınkor (Ferulago stellata) were determined by liquid chromatography-high-resolution mass spectrometry (LC-HRMS). Ethanol and water extracts of kınkor (Ferulago stellata) demonstrated effective antioxidant abilities when compared to standards. Moreover, ethanol extract of kınkor (Ferulago stellata) demonstrated IC50 values of 1.772 μg/mL against acetylcholinesterase (AChE), 33.56 ± 2.96 μg/mL against α-glycosidase, and 0.639 μg/mL against α-amylase enzyme respectively