Kafes Yapıların Modifiye Edilmiş Yapay Arı Koloni Algoritması İle Optimizasyonu

Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2013Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2013Bu çalışmada, kafes yapıların optimizasyonunda modifiye edilmiş yapay arı koloni algoritması (MABC) kullanılmıştır. Yapay arı koloni algoritması (ABC); arı kolonilerindeki çalışma mekanizması ve arıların nektar elde etmek için izledikleri stratejilerin taklit edilmesini esas alan sezgisel optimizasyon yöntemidir. Optimizasyon probleminin formülasyonunda; deplasman ve gerilme sınırlayıcıları altında minimum ağırlıklı kafes yapı’nın elde edilmesi amaçlanmaktadır. Yöntemin etkinliği daha önce standart yapay arı koloni algoritması ve farklı sezgisel optimizasyon yöntemleriyle kullanılarak optimum tasarımı yapılmış 200 elemanlı, 29 tasarım değişkenli kafes yapı üzerinde test edilmiştir. Yapılan kıyaslamalar; modifiye edilmiş yapay arı koloni algoritmasının, standart yapay arı koloni algoritması ve diğer optimizasyon yöntemlerine göre daha iyi bir tasarım elde ettiğini göstermiştir. Anahtar Kelimeler: Kafes yapılar, Modifiye edilmiş yapay arı koloni algoritması, Optimizasyo

Tight contact structures on hyperbolic three-manifolds

Let Sigma(g) denote a closed orientable surface of genus g >= 2. We consider a certain infinite family of Sigma(g)-bundles over circle whose monodromies are taken from some collection of pseudo-Anosov diffeomorphisms. We show the existence of tight contact structure on every closed 3-manifold obtained via rational r-surgery along a section of any member of the family whenever r not equal 2g - 1. Combining with Thurston's hyperbolic Dehn surgery theorem, we obtain infinitely many hyperbolic closed 3-manifolds admitting tight contact structures

Aksaraylı Bir Ermeni’nin Anıları

Kevork ŞAHİNYAN, şu anda İstanbul Kadıköy’de ikamet eden ve aslen Aksaraylı olan hemşerimizdir. Kendisiyle yaklaşık bir buçuk yıl önce tanıştık. Çok hoş sohbet birisi… Aksaray’ı ve burada bıraktığı arkadaşlarını çok özlediğini söyleyince anılarını yazmasını rica ettim. O da beni kırmadı. Tarafıma gönderilen mektup aşağıdaki gibidir: “Aksaray’a ait orada yaşamış bir Ermeni olarak hatıralarımı yazmaktan şeref duyarım. Ben 1936 Aksaray doğumlu Kevork Şahinyan. Aksaray’ımızda ben çocukken 30 haneye yakın Ermeni vardı. Büyükannemin anlattığına göre Aksaray’da yedi göbekten beri biz buranın yerlisiyiz derdi. Zaten Ihlara-göreme-Aksaray-Ürgüp-Kapadokya mıntıkası olarak bilinir. 500 sene evvel Hıristiyanların yoğun olarak yaşadıkları yerlermiş. Gelelim Aksaray’ımızdaki Ermeni halkının yaşantısına ve durumuna. Aksaray’da yaşayan Ermeni ailelerinin çoğu sanatkârdı. Terzi, soğuk demirci, marangoz, kunduracıydı. Sadece babam Garbis Şahinyan, Aram Piran’ın babası Artin Piran ve Vicen Şımarmaz tüccardı. Hububat, bakliyat, tiftik, yapağı ticareti yaparlardı. Köylülerden malları alır, İstanbul’a, Adana’ya vs illere satarlardı. Başka türlerden de tüccarlar vardı. Aramızda hiçbir şekilde rekabet, kıskançlık, münakaşa olmazdı. Bazen ortaklaşa mallar alır, beraber pazarlardık. Gelelim diğer vatandaşlarımıza

Antimicrobial activity of galls of Quercus infectoria

Objectives: Gall oak (Quercus infectoria) is a species of tree belonging to fagaceae family and its galls has been used in the treatment of burn wounds traditionally. In this study, it is aimed to investigate the antimicrobial activity of the extract of oak galls on some microorganisms.Materials and methods: With using microdilution method, a solution which was obtained by boiling the galls was studied on 20 staphylococci, 20 Pseudomonas aeruginosa and 20 Candida albicans isolates which were obtained from various clinical samples and the values of minimum inhibitor concentration (MIC) were detected.Results: At the end of incubation MIC50 and MIC90 values were determined as 0,5 and 1 μg/ml for staphylococci, 1 and 2 μg/ml for Pseudomonas, 2 and 2 μg/ml for Candida, respectively.Conclusion: As a result, we concluded that galls of Q.infectoria has antimicrobial effect on common factors of burn wound infections. Larger studies about the antimicrobial and antiinflamatorial activity and in vivo effect of topical treatment of Q.infectoria will obtain more accurate data about using this plant in the treatment of burn wounds

Physically based deformable object modeling and soft tissue deformation

Bilgisayar destekli sanal ameliyat benzetimleri ve farklı alanlardaki uygulamaları, birçok parametrenin olası en doğru biçimde belirlendiği ve uygulandığı matematiksel modellerle mümkündür. Bu parametreler benzetimi yapılacak biyolojik yapıların geometrik sınırlarının, organ özelliklerinin, farklı kuvvetler altındaki davranışlarının ve en önemlisi dokuya ait malzeme parametrelerinin olası en doğru biçimde belirlenmesi ile elde edilir. Bu çalışma yumuşak dokuların doğrusal olmayan, viskoelastik davranışlarının matematiksel olarak modellenmesi ve önerilen bu modelin sonlu elemanlar yöntemi kullanılarak sayısal olarak çözülmesine odaklanmıştır. Örnek organ olarak seçilen insan karaciğerine ait malzeme katsayıları, hastane ortamında canlı dokular üzerinde yapılan deney sonuçları kullanılarak doğrusal olmayan eniyileme yöntemi ile elde edilmiştir. Uygulanan genel yaklaşımlardan farklı olarak benzetim sonuçlarının çözümden önce yani modelleme aşamasında yapılan ön basitleştirmelerden etkilenmemesi ilkesi benimsenmiştir. Bu nedenle, modelleme aşamasında uygulanan ve gerçeklikten uzaklaşılması ile sonuçlanan geleneksel basitleştirme adımları uygulanmamış, bu yaklaşım yerine tam çözümü veren benzetim sonuçları üzerinde model indirgeme teknikleri uygulanmıştır. İlk aşama olarak yumuşak dokuların önemli özelliklerini içeren bir model önerilmiş, sonrasında oluşturulan bu model sonlu elemanlar yöntemi kullanılarak analiz edilmiştir. Analiz sonrası elde edilen sonuçlar bir sonraki aşamada kullanılmak üzere saklanmıştır. İkinci adımda saklanan sonuçlar üzerinde Karhunen Loeve model indirgeme yöntemi kullanılarak, ilk adımda elde edilen sonuçlara yakın değerleri gerçek zamanlı sunabilen bir çözüm elde edilmiştir. Son adımda ise basitleştirilmemiş model ile indirgenmiş model sundukları hızlar ve sonuçların doğrulukları açısından karşılaştırılmıştır. Anahtar Kelimeler: Yumuşak dokular, sonlu elemanlar yöntemi, model indirgeme, viskoelastisite.As indicated by The Institute of Medicine Report, 44,000 to 98,000 people die annually as a result of procedure mistakes in surgery. The main reason cited was the young surgeons' insufficient experience of new techniques before facing real-world surgical operations. With the use of virtual surgery, surgeons have the opportunity to test different critical surgical procedures in a low- cost, ethically sound environment. The virtual surgery simulators equipped with physically based modeling engines are outstanding candidates for the simulation of deformable human organs. The real time soft tissue simulation has gained a great interest recently as a result of advancements in areas such as surgery planning and the surgical simulations. Linear deformation models may not provide the required accuracy in such areas whilst nonlinear models do not serve the real time needs. Therefore, there is a common need for a computationally simplified yet accurate, nonlinear, large deformable viscoelastic model of soft tissues to be used in these real time applications. Computer aided surgery and surgery simulation applications require accurate form and feature description as well as proper material and behavior descriptions of the biological tissues in a mathematically formulated model. This study focuses on mathematical formulation and numerical implementation of a nonlinear viscoelastic model of soft tissues using Finite Element Method (FEM). As an object, a human liver is selected in our study. The necessary material parameters are extracted from results of in vivo material tests on human liver using a nonlinear optimization method. Due to the technology limitations, today's physics based surgery simulators are forced to use different simplification methods to obtain satisfactory visual effects and response time in delivering an acceptable visual and haptic user experience. Thus, previous approaches to this problem involve techniques in the simplification of the mathematical models prior to obtain the necessary numerical solutions. The model simplification is necessary to achieve the required computational speeds however; these simplifications will inevitably result in reduced accuracy. Unlike the above mentioned approaches, our research is based on the opposite view that accuracy should not unduly influenced due to premature model simplifications prior to the analysis. Therefore, simplification step that is applied in the modeling phase, resulting in inaccurate outcome, is displaced to be applied after the solution phase. This aims to limit the degradation of already calculated values. As the first step, a complete soft tissue model is created. Subsequently this model is analyzed using Finite Element Method (FEM) and the results are stored and are used as the input to the next stage. Then, the Karhunen-Loeve decomposition technique is used to simplify the previously obtained data resulting in the final simulated model. Simplification technique is necessary to achieve acceptable real-time update rates due to the computing power available. Finally, a complete (unsimplified) model is compared with the simplified model in terms of accuracy and speed. Since soft tissues undergo large deformations under applied load and required volume preservation behavior, the use of linear strain tensor is not suitable for the accurate modeling of the resulting large deformations involved. Limitation of using a linear strain tensor is overcome by the use of nonlinear Green strain tensor in our customized FEM code. Standard material tests on human liver reveal the material nonlinearity relationship between applied forces and the resulting displacements. This nonlinear behavior is necessitated the use of hyperelastic strain energy density function in our FEM implementation. Viscoelastic behavior is also a predominant feature of soft tissues that must be included in any soft tissue deformation simulation. Therefore, the quasi-linear viscoelastic behavior of a human liver is added to our implementation to provide for this need. To implement time dependent viscoelastic behavior in improved the reduced order model, the surface nodes and its neighboring nodes are determined inside the Radius of Influence (ROI). Then, a constant unit force is applied to each of surface nodes for a period of 20 seconds. It is assumed that the creep response of the soft tissue lasts for 20 seconds due to the limitations of data storage and higher computational costs. Our proposed model, when employed, results in a final constitutive equation that successfully produces accurate results while catering for the whole previously mentioned phenomenon namely; geometric and material nonlinearity, volume preservation, viscoelasticity. Keywords: Real-time simulation; deformable models; model order reduction; nonlinear simulations; soft tissue; viscoelasticity

Proximal aortic arch cannulation for proximal ascending aortic aneurysms

Introduction: Different arterial inflow sites have been reported to date for particularly challenging cardiac operations. The ascending aorta, femoral artery, and subclavian artery are the most commonly used sites. Although its use has been reported, the aortic arch has not gained popularity in the performance of cannulation. According to a search performed in the PubMed database, aortic arch cannulation for ascending aorta replacement has not been examined in a separate study before. In the present study, we report the treatment outcomes of patients with ascending aortic aneurysms in whom the aortic arch was cannulated for arterial inflow. Material and methods: Twenty-seven patients with aneurysmal dilatation of the ascending aorta underwent ascending aorta replacement from April 2010 to March 2013. The mean age of the patients was 64 years. All operations were carried out by cannulating the aortic arch distally from the origin of the innominate artery. Results: There was no mortality or cannulation-related morbidity. In 23 patients, only the supracoronary ascending aorta was replaced, whereas in 4 patients, the button modification of the Bentall procedure was performed to replace the root and the ascending aorta. Conclusions: The technique of aortic arch cannulation distal to the origin of the innominate artery is worthy of consideration in the treatment of aneurysms limited to the ascending aorta due to its safety, simplicity, and low morbidity

Evaluation of the genotoxicity and cytotoxicity in the buccal epithelial cells of patients undergoing orthodontic treatment with three light-cured bonding composites by using micronucleus testing

Objective: This study evaluated the cytotoxicity and genotoxicity of fixed orthodontic treatment with three different light-cured orthodontic bonding composites by analyzing micronucleus (MN) formation in the buccal mucosa during a 6-month period. Methods: Thirty healthy volunteers were selected from consecutive patients referred for orthodontic treatment. Equilibrium 2 brackets and molar tubes (Dentaurum) were bonded with three different lightcured orthodontic bonding composites-Transbond XT (3M Unitek), Kurasper F (Kuraray Europe), or GrenGloo (Ormco Corporation)- to all teeth in both arches. Exfoliated buccal epithelial cells were scraped from the middle part of the inner cheeks with sterile cement spatulas before treatment and at 1, 3, and 6 months after treatment. MNs and nuclear alterations, such as karyorrhexis (KR), karyolysis (KL), and binucleated cells (BNs), were scored under a light microscope. Repeated measure ANOVA was used to calculate statistical differences in degenerative nuclear abnormalities. Results: MN rates did not significantly differ among different time points within the same cell type (p > 0.05). In contrast, the number of BNs in buccal epithelial cells significantly increased in all composite groups (p < 0.01, Transbond XT; p < 0.001, Kurasper F and GrenGloo). KL frequency significantly increased between the beginning and end of the study in the Kurasfer F (0.80 ± 0.79 to 1.90 ± 1.10; p < 0.05) and GrenGloo (1.30 ± 1.06 to 2.40 ± 1.08; p < 0.05) groups. Conclusions: After 6 months of fixed orthodontic treatment with different light-cured composites, morphological signs of cytotoxicity were observed but genotoxic effects were absent. © 2014 The Korean Association of Orthodontists

The trend of breeding value research in animal science: bibliometric analysis

This study aims to identify trends and hot topics in breeding value to support researchers in finding new directions for future research in that area. The data of this study consist of 7072 academic studies on breeding value in the Web of Science database. Network visualizations and in-depth bibliometric analysis were performed on cited references, authors, countries, institutions, journals, and keywords through CiteSpace. VanRaden (2008) is the most cited work and has an essential place in the field. The most prolific writer is Ignacy Misztal. While the most productive country in breeding value studies is the United States, the People's Republic of China is an influential country that has experienced a strong citation burst in the last 3 years. The National Institute for Agricultural Research and Wageningen University are important institutions that play a critical role in connecting other institutions. Also, these two institutions have the highest centrality values. “Genomic prediction” is the outstanding sub-study field in the active clusters appearing in the analysis results. We have summarized the literature on breeding value, including publication information, country, institution, author, and journal. We can say that hot topics today are “genome-wide association”, “feed efficiency”, and “genomic prediction”. While the studies conducted in the past years have focused on economic value and accuracy, the studies conducted in recent years have started to be studies that consider technological developments and changing world conditions such as global warming and carbon emission.</p

Initial Psychometric Evaluation of the Physical Health Attitude Scale and a Survey of Mental Health Nurses

INTRODUCTION: Nurses play an important role in improving the physical health of individuals with serious mental illnesses. The literature on the attitudes of mental health nurses towards physical healthcare provides a small amount of data. Assessing trends in nurses' attitudes through suitable surveys is important to ensure holistic care. AIM/QUESTION: This study sought to examine the Turkish version of the Physical Health Attitude Scale's (PHASe) validity and reliability and to survey Turkish mental health nurses' attitudes towards physical healthcare. METHOD: The sample consisted of 174 nurses working in acute psychiatric wards. Firstly, the psychometric properties of the scale were analyzed using factor analysis and measures of internal consistency and reliability. Then, the survey results of the attitudes of mental health nurses towards the physical health of patients with serious mental illnesses were determined using the Physical Health Attitude Scale (PHASe). RESULTS: The translated PHASe scale functioned best as a 24-item version and 4-factor solution that explains 51.3% of the variance. The internal consistency value was .83. The respondents' attitudes were generally positive about their role. There was less agreement for the involvement of nurses in practices of health promotion, such as sexual health, eye and/or dental examinations. The nurses surveyed also tended to use smoking for therapeutic purposes. IMPLICATIONS FOR PRACTICE: Mental health nurses' knowledge and attitudes should be enhanced by additional training in the ways of meeting patients' biopsychosocial needs. Obstacles to physical healthcare can be removed by implementing standard protocols nationwide. This article is protected by copyright. All rights reserved