Rasim Temur | Istanbul University-Cerrahpaşa (original) (raw)

Papers by Rasim Temur

Natural Hazards, 2021

The earthquake in Sivrice, the district of Elazığ, took place at 20:55 (with local time, GMT+3) o... more The earthquake in Sivrice, the district of Elazığ, took place at 20:55 (with local time, GMT+3) on January 24, 2020, with a magnitude of 6.8 in Turkey. This earthquake was felt in some districts and villages of Malatya as well as Elazig province and caused loss of life and property. After the earthquake, on-site investigations were carried out in the earthquake area. It was observed that liquefaction and lateral spreading occurred in alluvium soil deposits that are considered to be close to surface at lake shores and reservoir of the dams, but no soil-induced damage was observed in the city center. It is understood that extensive geotechnical investigations should be carried out in order to prevent damage to the structures due to soil problems in case of larger earthquakes. The common observed structural damages in the reinforced concrete (RC) buildings occurred due to short column effect, large and heavy overhangs, beam discontinuity, workmanship defects, and lack of control. Along...

2013 6th International Conference on Recent Advances in Space Technologies (RAST), 2013

Tensile integrity (tensegrity, tensegric) structures are suggested for possible use in outer spac... more Tensile integrity (tensegrity, tensegric) structures are suggested for possible use in outer space and on space bodies because of their minimal need for structural materials, ease of transfer and mounting. Structurally their behavior is non-linear. It has been shown here that their structural analysis can successfully be performed by total potential optimization using meta-heuristic algorithms (TPO/MA). The named method is an emerging technique that combines minimum energy principle of mechanics with metaheuristic algorithms. The technique thus defined has been shown to be very efficient, accurate and robust in analyzing structures. The success of the technique is especially profound for non-linear structures. In this study the named technique is applied to tensile integrity (tensegrity, tensegric) structures which are known to be highly nonlinear, thus difficult to analyze.

Case Studies in Construction Materials, 2015

In the analyses of truss structures, thermal loadings may to be critical effects in term of displ... more In the analyses of truss structures, thermal loadings may to be critical effects in term of displacement and additional stress in members, particularly for long spans. This paper present nonlinear analysis of truss structures subjected to thermal loading effects by Total Potential Optimization using Meta-heuristic Algorithms (TPO/MA) technique which is developed from the idea of using the optimization algorithm for obtaining the deformed shape of system with minimum potential energy instead of using matrix operations in conventional methods. This technique has been employed for solving problems such as linear /nonlinear behavior of plane and space truss structures, elasto-plastic behavior of truss systems, unilateral boundary condition, cable nets and tensegrity structures. Studies on application of beams, plates and shells studies are also continuing. In his study, besides describing the methodology of the TPO/MA in general terms, the application of truss structures under thermal effect is investigated to shown accuracy, robustness and reliability of the method.

During the design process of a structure, an important matter is to determine boundary condition ... more During the design process of a structure, an important matter is to determine boundary condition of the joint. Incorrectly specified boundary conditions can decrease the analyses time and can also cause incorrect results. According to displacement capability of the joint the most appropriate condition within the existing onesi.e. hinged, sliding, fixed etc., is selected and assigned to joint. Except the existing conditions; some special conditions, such as unilateral boundaries can also identify for a joint. The unilateral boundary condition can be observed at soil-structure interaction where both tensile and compressive stresses are occurred under the foundation because of axial force eccentricity. In this paper, behavior of the truss structures with unilateral boundary conditions is presented. The analyses are conducted by using Total Potential Optimization using Meta-heuristic Algorithms (TPO/MA) technique, that developed methodology based on improved In order to apply to the problem The methodology of the paper was developed based on an improved Particle Swarm Optimization(PSO) algorithm. The analyses results have proved that the applied technique is efferent and suitable for solving this kind of problem.

The nonlinear behavior of the structure is an important subject that must be taken into considera... more The nonlinear behavior of the structure is an important subject that must be taken into consideration during the structural design. This behavior can occur due to large deformations and/or material nonlinearity. Elasto-plastic behavior is a well-known idealization that makes the structure highly nonlinear. By using the method of Total Potential Optimization using Meta-heuristic Algorithms (TPO/MA), this behavior can be easily taken into consideration, whether the deformations are large or not. According to total potential energy theory, the structure is in equilibrium when the energy of the structure is minimum. The idea of using metaheuristic algorithms for this minimization process is resulted in the TPO/MA method. In this study, the TPO/MA method of analyses of truss structures are presented considering the elasto-plastic behavior. As a metaheuristic algorithm, the harmony search (HS) algorithm is employed. The analyses presented show that the technique is feasible, robust and effective in solving these kinds of problems.

Cable and tensegrity structures give an ability to create new structural forms in the architectur... more Cable and tensegrity structures give an ability to create new structural forms in the architectural designs which are light and flexible. Since their flexibility allows large structural displacements, a geometrically nonlinear solution method has to be used during the analysis of this type of structures. A further reason for adopting a nonlinear method is the unsymmetrical stress-strain behavior of the cables, since they do not carry compressive forces. It is also to be noted that these structures are usually designed in such a way that the elements are all pretensioned. In this study, the analyses of cable and tensegrity structures are carried on by Total Potential Optimization using Meta-heuristicAlgorithms (TPO/MA) which is an emerging method applied especially to trusses and truss-like structures. The TPO/MA method searches the displacements of structure where the minimum potential energy has been achieved. Energy equations are derived on the deformed shape of the structure. Thus, geometric nonlinearity has already been taken care of. The method has already been applied with various meta-heuristic algorithms. In the present study, Harmony Search (HS) algorithm is employed for the optimization process, and it has been shown that the applied technique is robust with respect to parameters adopted and the problems tackled.

Internal forces and displacement caused from the thermal effects can be important for structures ... more Internal forces and displacement caused from the thermal effects can be important for structures that can be subject to large temperature changes. For that reason, determining these effects accurately during the design process is essential for security of structural systems. In this paper, a methodology called total potential optimization using metaheuristic algorithms (TPO/MA) that has been successfully applied for analyzing different types of systems such as truss, cables and tensegrity structures, is presented for investigation of analyses of truss structures considering thermal effects. Teaching learning based optimization (TLBO) algorithm is employed as metaheuristic approach. Results are compared with other methods that used wellknown metaheuristic approach harmony search (HS) and finite element method (FEM). According to results, proposed approach is accurate, robust and reliable for the analyses of this kind of problem.

Total Potential Optimization using Meta-heuristic Algorithms (TPO/MA) is an analyses technique de... more Total Potential Optimization using Meta-heuristic Algorithms (TPO/MA) is an analyses technique developed by implementation of metaheuristic algorithms for finding an equilibrium state of a structural system according to the well-known principle of minimum total potential energy. According to this theory, a system is in equilibrium state only if total potential energy of it which means sum of the strain energy and work done by external loads is minimum. This paper presents a methodology for TPO/MA analyses of truss structures considering elastoplastic behavior of material and geometrical nonlinear behavior of system. Methodology is developed based on one of the recently proposed metaheuristic algorithm called teaching learning based optimization (TLBO) method. In order to put for the effectiveness or ineffectiveness of presented method for problem, results are compared with existing ones from the literature. According to results, TLBO is more effective in computational cost than others.

Particle swarm optimization (PSO) algorithm is a heuristic optimization technique based on colony... more Particle swarm optimization (PSO) algorithm is a heuristic optimization technique based on colony intelligence, developed through inspiration from social behaviors of bird flocks and fish schools. It is widely used in problems in which the optimal value of an objective function is searched. Geometrically nonlinear analysis of trusses is a problem of this kind. The deflected shape of the truss where potential energy value is minimal is known to correspond to the stable equilibrium position of the system analyzed. The objective of this study is to explore the success of PSO using this minimum total potential energy principle, in finding good solutions to geometrically nonlinear truss problems. For this purpose analyses are conducted on three structures, two plane trusses and a space truss. The results obtained show that in case of using 20 or more particles, PSO produces very good and robust solutions.

Determination of nonunique configurations of structures is a problem which cannot be treated read... more Determination of nonunique configurations of structures is a problem which cannot be treated readily using classical methods of analysis. In the literature, these kinds of problems are tackled for some simple problems, like trusses with a small number of joints and members, and with specially designed approaches. The recent method of analysis called Total Potential Optimization using Metaheuristic Algorithms (TPO/MA), on the other hand, provides an efficient tool for dealing with these kinds of problems, practically without recourse to any special arrangement. In this analysis, using Harmony Search as the metaheuristic algorithm, large truss structures with linear elastic members are investigated under large deflections as to the existence of more than one solution. The results have shown that for the two examples investigated, a tower truss with 25 members and a dome truss with 24 members, nonunique configurations do exist at quite unexpected levels of loads, and that only one of them can be found with normal applications of the well-known Finite Element method.

İstanbul Üniversitesi Cerrahpaşa Yerleşkesinde yer alan yapıların deprem etkileri açısından risk ... more İstanbul Üniversitesi Cerrahpaşa Yerleşkesinde yer alan yapıların deprem etkileri açısından risk analizinin yapılmasını amaçlayan çalışma kapsamında, hastane olarak servis veren 57 adet yapı irdelenmiştir. Emniyetinin belirlenmesi gereken yapı sayısının sahip olunan süre açısından oldukça fazla olması, söz konusu yapıların doğal olarak yapım yılı mimari alışkanlıkları ve kullanım amacı nedeniyle karmaşık, aynı zamanda düzensiz olmaları nedeniyle analizlerde Hızlı Durum Tespit (DURTES) Yöntemi kullanılmıştır. Üç temel aşamadan oluşan söz konusu çalışmanın ilk evresinde, saha etabına esas teşkil eden bilgilerin derlenmesi açısından değerlendirme kapsamındaki yapılara kimlik bilgilerinin atanması ve mevcut projelerinin tedarik edilmesi işlemlerini içeren arşiv çalışması gerçekleştirilmiştir. İlgili etabın tamamlanması ile birlikte oluşturulan saha ekipleriyle, kullanılan yöntemin veri toplama formları yardımıyla, kapsam dâhilindeki binaların yapısal karakteristiklerinin elde edilmesini içeren ikinci etap çalışmaları tamamlanmıştır. Mevcut çalışmanın son aşamasında ise sahadan gelen veriler, DURTES yönteminin algoritmasını kullanan ve söz konusu yöntem için özel olarak geliştirilen yazılıma girilerek, risk analizleri hızlı bir şekilde gerçekleştirilmiştir. Nümerik analizler neticesinde; ortak alan içerisinde yer alan ve tümü nitelikli yapılar olan binaların mevcut durumları deprem riski açısından konvansiyonel analizlere göre oldukça hızlı bir şekilde tespit edilmiştir. Her bir yapının risk seviyesi net bir şekilde belirlenmiştir. İnceleme kapsamındaki 19 binanın “Çok Yüksek Risk”, 24 binanın “Yüksek Risk”, 4 binanın “Orta Risk”, 5 binanın “Düşük Risk” ve 5 binanın “Minimum Risk” seviyesinde olduğu tespit edilmiştir.

Müzisyen doğaçlaması benzetimi ile üretilen sezgisel bir algoritma olarak tanımlanan Harmoni Aram... more Müzisyen doğaçlaması benzetimi ile üretilen sezgisel bir algoritma olarak tanımlanan Harmoni Arama (HA) yöntemi, en uygunluğun arandığı pek çok mühendislik probleminde uygulanan bir optimizasyon algoritmasıdır. Bu çalışmada, en uygunluğun, ulaştırmada talep tahmini konusunda incelemesi yapılmış, yarar fonksiyonuna göre değişkenlerin ağırlığını ifade eden katsayılar elde edilmiş ve gerçek değerler ile yakınlık sayısal olarak ifade edilmiştir. Çalışmada, regresyon analizi ile incelenmiş bir ulaşım problemi, HA metoduyla ele alınmıştır. Analizler sonucunda HA yönteminin gerçek verilere daha yakın değerler üretebildiği gözlenmiştir.

Current methods of analysis of trusses depend on matrix formulations based on equilibrium equatio... more Current methods of analysis of trusses depend on matrix formulations based on equilibrium equations which are in fact derived from energy principles, and compatibility conditions. Recently it has been shown that the minimum energy principle, by itself, in its pure and unmodified form, can well be exploited to analyze structures when coupled with an optimization algorithm, specifically with a meta-heuristic algorithm. The resulting technique that can be called Total Potential Optimization using Meta-heuristic Algorithms (TPO/MA) has already been applied to analyses of linear and nonlinear plane trusses successfully as coupled with simulated annealing and local search algorithms. In this study the technique is applied to both 2-dimensional and 3-dimensional trusses emphasizing robustness, reliability and accuracy. The trials have shown that the technique is robust in two senses: all runs result in answers, and all answers are acceptable as to the reliability and accuracy within the prescribed limits. It has also been shown that Harmony Search presents itself as an appropriate algorithm for the purpose.

istanbul.edu.tr

Deprem zararlarını azaltma stratejilerinin çekirdek kısmını oluşturan, mevcut yapıların deprem gü... more Deprem zararlarını azaltma stratejilerinin çekirdek kısmını oluşturan, mevcut yapıların deprem güvenliğinin belirlenmesi konusu kendine özgü şartlar sebebiyle yeni yaklaşımlar, yöntemler ve araçlar gerektirmektedir. Kısa sürede doğruya en yakın sonuçları elde etmeyi amaçlayan bu yöntemlerin hesap adımlarının fazlalığı ve karmaşıklığı nedeniyle yardımcı yazılımlar geliştirilmesine ihtiyaç duyulmaktadır. Mevcut çalışmada "Hızlı Durum Tespit Yöntemi(DURTES)" yazılımı için bilgi giriş, raporlama ve çizim modülleri geliştirilmiştir. Geliştirilen modüllerle puanlama ve röleve bilgilerinin girişinde harcanan süre azalmış, raporlama ve çizim seçenekleri geliştirilmiş, kullanım kolaylığı ve farklı yazılımlarla etkileşim sağlanmıştır. Oluşturulan data dosyası mevcut yazılımda da kullanılabilmektedir.

Natural Hazards, 2021

The earthquake in Sivrice, the district of Elazığ, took place at 20:55 (with local time, GMT+3) o... more The earthquake in Sivrice, the district of Elazığ, took place at 20:55 (with local time, GMT+3) on January 24, 2020, with a magnitude of 6.8 in Turkey. This earthquake was felt in some districts and villages of Malatya as well as Elazig province and caused loss of life and property. After the earthquake, on-site investigations were carried out in the earthquake area. It was observed that liquefaction and lateral spreading occurred in alluvium soil deposits that are considered to be close to surface at lake shores and reservoir of the dams, but no soil-induced damage was observed in the city center. It is understood that extensive geotechnical investigations should be carried out in order to prevent damage to the structures due to soil problems in case of larger earthquakes. The common observed structural damages in the reinforced concrete (RC) buildings occurred due to short column effect, large and heavy overhangs, beam discontinuity, workmanship defects, and lack of control. Along...

2013 6th International Conference on Recent Advances in Space Technologies (RAST), 2013

Tensile integrity (tensegrity, tensegric) structures are suggested for possible use in outer spac... more Tensile integrity (tensegrity, tensegric) structures are suggested for possible use in outer space and on space bodies because of their minimal need for structural materials, ease of transfer and mounting. Structurally their behavior is non-linear. It has been shown here that their structural analysis can successfully be performed by total potential optimization using meta-heuristic algorithms (TPO/MA). The named method is an emerging technique that combines minimum energy principle of mechanics with metaheuristic algorithms. The technique thus defined has been shown to be very efficient, accurate and robust in analyzing structures. The success of the technique is especially profound for non-linear structures. In this study the named technique is applied to tensile integrity (tensegrity, tensegric) structures which are known to be highly nonlinear, thus difficult to analyze.

Case Studies in Construction Materials, 2015

In the analyses of truss structures, thermal loadings may to be critical effects in term of displ... more In the analyses of truss structures, thermal loadings may to be critical effects in term of displacement and additional stress in members, particularly for long spans. This paper present nonlinear analysis of truss structures subjected to thermal loading effects by Total Potential Optimization using Meta-heuristic Algorithms (TPO/MA) technique which is developed from the idea of using the optimization algorithm for obtaining the deformed shape of system with minimum potential energy instead of using matrix operations in conventional methods. This technique has been employed for solving problems such as linear /nonlinear behavior of plane and space truss structures, elasto-plastic behavior of truss systems, unilateral boundary condition, cable nets and tensegrity structures. Studies on application of beams, plates and shells studies are also continuing. In his study, besides describing the methodology of the TPO/MA in general terms, the application of truss structures under thermal effect is investigated to shown accuracy, robustness and reliability of the method.

During the design process of a structure, an important matter is to determine boundary condition ... more During the design process of a structure, an important matter is to determine boundary condition of the joint. Incorrectly specified boundary conditions can decrease the analyses time and can also cause incorrect results. According to displacement capability of the joint the most appropriate condition within the existing onesi.e. hinged, sliding, fixed etc., is selected and assigned to joint. Except the existing conditions; some special conditions, such as unilateral boundaries can also identify for a joint. The unilateral boundary condition can be observed at soil-structure interaction where both tensile and compressive stresses are occurred under the foundation because of axial force eccentricity. In this paper, behavior of the truss structures with unilateral boundary conditions is presented. The analyses are conducted by using Total Potential Optimization using Meta-heuristic Algorithms (TPO/MA) technique, that developed methodology based on improved In order to apply to the problem The methodology of the paper was developed based on an improved Particle Swarm Optimization(PSO) algorithm. The analyses results have proved that the applied technique is efferent and suitable for solving this kind of problem.

The nonlinear behavior of the structure is an important subject that must be taken into considera... more The nonlinear behavior of the structure is an important subject that must be taken into consideration during the structural design. This behavior can occur due to large deformations and/or material nonlinearity. Elasto-plastic behavior is a well-known idealization that makes the structure highly nonlinear. By using the method of Total Potential Optimization using Meta-heuristic Algorithms (TPO/MA), this behavior can be easily taken into consideration, whether the deformations are large or not. According to total potential energy theory, the structure is in equilibrium when the energy of the structure is minimum. The idea of using metaheuristic algorithms for this minimization process is resulted in the TPO/MA method. In this study, the TPO/MA method of analyses of truss structures are presented considering the elasto-plastic behavior. As a metaheuristic algorithm, the harmony search (HS) algorithm is employed. The analyses presented show that the technique is feasible, robust and effective in solving these kinds of problems.

Cable and tensegrity structures give an ability to create new structural forms in the architectur... more Cable and tensegrity structures give an ability to create new structural forms in the architectural designs which are light and flexible. Since their flexibility allows large structural displacements, a geometrically nonlinear solution method has to be used during the analysis of this type of structures. A further reason for adopting a nonlinear method is the unsymmetrical stress-strain behavior of the cables, since they do not carry compressive forces. It is also to be noted that these structures are usually designed in such a way that the elements are all pretensioned. In this study, the analyses of cable and tensegrity structures are carried on by Total Potential Optimization using Meta-heuristicAlgorithms (TPO/MA) which is an emerging method applied especially to trusses and truss-like structures. The TPO/MA method searches the displacements of structure where the minimum potential energy has been achieved. Energy equations are derived on the deformed shape of the structure. Thus, geometric nonlinearity has already been taken care of. The method has already been applied with various meta-heuristic algorithms. In the present study, Harmony Search (HS) algorithm is employed for the optimization process, and it has been shown that the applied technique is robust with respect to parameters adopted and the problems tackled.

Internal forces and displacement caused from the thermal effects can be important for structures ... more Internal forces and displacement caused from the thermal effects can be important for structures that can be subject to large temperature changes. For that reason, determining these effects accurately during the design process is essential for security of structural systems. In this paper, a methodology called total potential optimization using metaheuristic algorithms (TPO/MA) that has been successfully applied for analyzing different types of systems such as truss, cables and tensegrity structures, is presented for investigation of analyses of truss structures considering thermal effects. Teaching learning based optimization (TLBO) algorithm is employed as metaheuristic approach. Results are compared with other methods that used wellknown metaheuristic approach harmony search (HS) and finite element method (FEM). According to results, proposed approach is accurate, robust and reliable for the analyses of this kind of problem.

Total Potential Optimization using Meta-heuristic Algorithms (TPO/MA) is an analyses technique de... more Total Potential Optimization using Meta-heuristic Algorithms (TPO/MA) is an analyses technique developed by implementation of metaheuristic algorithms for finding an equilibrium state of a structural system according to the well-known principle of minimum total potential energy. According to this theory, a system is in equilibrium state only if total potential energy of it which means sum of the strain energy and work done by external loads is minimum. This paper presents a methodology for TPO/MA analyses of truss structures considering elastoplastic behavior of material and geometrical nonlinear behavior of system. Methodology is developed based on one of the recently proposed metaheuristic algorithm called teaching learning based optimization (TLBO) method. In order to put for the effectiveness or ineffectiveness of presented method for problem, results are compared with existing ones from the literature. According to results, TLBO is more effective in computational cost than others.

Particle swarm optimization (PSO) algorithm is a heuristic optimization technique based on colony... more Particle swarm optimization (PSO) algorithm is a heuristic optimization technique based on colony intelligence, developed through inspiration from social behaviors of bird flocks and fish schools. It is widely used in problems in which the optimal value of an objective function is searched. Geometrically nonlinear analysis of trusses is a problem of this kind. The deflected shape of the truss where potential energy value is minimal is known to correspond to the stable equilibrium position of the system analyzed. The objective of this study is to explore the success of PSO using this minimum total potential energy principle, in finding good solutions to geometrically nonlinear truss problems. For this purpose analyses are conducted on three structures, two plane trusses and a space truss. The results obtained show that in case of using 20 or more particles, PSO produces very good and robust solutions.

Determination of nonunique configurations of structures is a problem which cannot be treated read... more Determination of nonunique configurations of structures is a problem which cannot be treated readily using classical methods of analysis. In the literature, these kinds of problems are tackled for some simple problems, like trusses with a small number of joints and members, and with specially designed approaches. The recent method of analysis called Total Potential Optimization using Metaheuristic Algorithms (TPO/MA), on the other hand, provides an efficient tool for dealing with these kinds of problems, practically without recourse to any special arrangement. In this analysis, using Harmony Search as the metaheuristic algorithm, large truss structures with linear elastic members are investigated under large deflections as to the existence of more than one solution. The results have shown that for the two examples investigated, a tower truss with 25 members and a dome truss with 24 members, nonunique configurations do exist at quite unexpected levels of loads, and that only one of them can be found with normal applications of the well-known Finite Element method.

İstanbul Üniversitesi Cerrahpaşa Yerleşkesinde yer alan yapıların deprem etkileri açısından risk ... more İstanbul Üniversitesi Cerrahpaşa Yerleşkesinde yer alan yapıların deprem etkileri açısından risk analizinin yapılmasını amaçlayan çalışma kapsamında, hastane olarak servis veren 57 adet yapı irdelenmiştir. Emniyetinin belirlenmesi gereken yapı sayısının sahip olunan süre açısından oldukça fazla olması, söz konusu yapıların doğal olarak yapım yılı mimari alışkanlıkları ve kullanım amacı nedeniyle karmaşık, aynı zamanda düzensiz olmaları nedeniyle analizlerde Hızlı Durum Tespit (DURTES) Yöntemi kullanılmıştır. Üç temel aşamadan oluşan söz konusu çalışmanın ilk evresinde, saha etabına esas teşkil eden bilgilerin derlenmesi açısından değerlendirme kapsamındaki yapılara kimlik bilgilerinin atanması ve mevcut projelerinin tedarik edilmesi işlemlerini içeren arşiv çalışması gerçekleştirilmiştir. İlgili etabın tamamlanması ile birlikte oluşturulan saha ekipleriyle, kullanılan yöntemin veri toplama formları yardımıyla, kapsam dâhilindeki binaların yapısal karakteristiklerinin elde edilmesini içeren ikinci etap çalışmaları tamamlanmıştır. Mevcut çalışmanın son aşamasında ise sahadan gelen veriler, DURTES yönteminin algoritmasını kullanan ve söz konusu yöntem için özel olarak geliştirilen yazılıma girilerek, risk analizleri hızlı bir şekilde gerçekleştirilmiştir. Nümerik analizler neticesinde; ortak alan içerisinde yer alan ve tümü nitelikli yapılar olan binaların mevcut durumları deprem riski açısından konvansiyonel analizlere göre oldukça hızlı bir şekilde tespit edilmiştir. Her bir yapının risk seviyesi net bir şekilde belirlenmiştir. İnceleme kapsamındaki 19 binanın “Çok Yüksek Risk”, 24 binanın “Yüksek Risk”, 4 binanın “Orta Risk”, 5 binanın “Düşük Risk” ve 5 binanın “Minimum Risk” seviyesinde olduğu tespit edilmiştir.

Müzisyen doğaçlaması benzetimi ile üretilen sezgisel bir algoritma olarak tanımlanan Harmoni Aram... more Müzisyen doğaçlaması benzetimi ile üretilen sezgisel bir algoritma olarak tanımlanan Harmoni Arama (HA) yöntemi, en uygunluğun arandığı pek çok mühendislik probleminde uygulanan bir optimizasyon algoritmasıdır. Bu çalışmada, en uygunluğun, ulaştırmada talep tahmini konusunda incelemesi yapılmış, yarar fonksiyonuna göre değişkenlerin ağırlığını ifade eden katsayılar elde edilmiş ve gerçek değerler ile yakınlık sayısal olarak ifade edilmiştir. Çalışmada, regresyon analizi ile incelenmiş bir ulaşım problemi, HA metoduyla ele alınmıştır. Analizler sonucunda HA yönteminin gerçek verilere daha yakın değerler üretebildiği gözlenmiştir.

Current methods of analysis of trusses depend on matrix formulations based on equilibrium equatio... more Current methods of analysis of trusses depend on matrix formulations based on equilibrium equations which are in fact derived from energy principles, and compatibility conditions. Recently it has been shown that the minimum energy principle, by itself, in its pure and unmodified form, can well be exploited to analyze structures when coupled with an optimization algorithm, specifically with a meta-heuristic algorithm. The resulting technique that can be called Total Potential Optimization using Meta-heuristic Algorithms (TPO/MA) has already been applied to analyses of linear and nonlinear plane trusses successfully as coupled with simulated annealing and local search algorithms. In this study the technique is applied to both 2-dimensional and 3-dimensional trusses emphasizing robustness, reliability and accuracy. The trials have shown that the technique is robust in two senses: all runs result in answers, and all answers are acceptable as to the reliability and accuracy within the prescribed limits. It has also been shown that Harmony Search presents itself as an appropriate algorithm for the purpose.

istanbul.edu.tr

Deprem zararlarını azaltma stratejilerinin çekirdek kısmını oluşturan, mevcut yapıların deprem gü... more Deprem zararlarını azaltma stratejilerinin çekirdek kısmını oluşturan, mevcut yapıların deprem güvenliğinin belirlenmesi konusu kendine özgü şartlar sebebiyle yeni yaklaşımlar, yöntemler ve araçlar gerektirmektedir. Kısa sürede doğruya en yakın sonuçları elde etmeyi amaçlayan bu yöntemlerin hesap adımlarının fazlalığı ve karmaşıklığı nedeniyle yardımcı yazılımlar geliştirilmesine ihtiyaç duyulmaktadır. Mevcut çalışmada "Hızlı Durum Tespit Yöntemi(DURTES)" yazılımı için bilgi giriş, raporlama ve çizim modülleri geliştirilmiştir. Geliştirilen modüllerle puanlama ve röleve bilgilerinin girişinde harcanan süre azalmış, raporlama ve çizim seçenekleri geliştirilmiş, kullanım kolaylığı ve farklı yazılımlarla etkileşim sağlanmıştır. Oluşturulan data dosyası mevcut yazılımda da kullanılabilmektedir.