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A Case Study of Shape Optimization Using Grasshopper Optimization Algorithm
No full textStructural optimization is a popular topic in today’s engineering and industry to reduce costs and obtain more ideal designs. In the structural optimization problem, the lightest design under conditions is investigated. Increasing studies in recent years have proven the success of metaheuristic optimization algorithms in structural optimization problems. Unlike the traditional method, metaheuristic methods use stochastic methods and do not need derivative information of the problem. This makes them more flexible and easy to use. In this study, a solid part’s shape optimization is performed by using the Grasshopper Optimization Algorithm (GOA). The design values and results found by the algorithm are discussed
Investigation and improvement of the effect of geometric dimensions and boundary conditions on critical buckling strength for thin plate structural parts in aerospace industry
No full textHavacılık sektöründe ve farklı sektörlerde ince kesit içeren yapısal parçalarda, yapının hafifletilmesi, erişim kolaylılığı ve sistem gereksinimleri gibi amaçlardan dolayı delik sıklıkla tercih edilen geometrik unsurlardan birisidir. Deliğin yapı üzerinde konumu, şekli, sayısı, boyutu, delik kenarında güçlendirme olup olmaması gibi farklı özellikler yapının dayanımı ve yapı üzerinde oluşan gerilim dağılımı değiştirerek burkulma dayanımını etkilemektedir. Geometrik unsurlar ile birlikte yapıya uygulanan yükleme türü, sınır koşulları, plakanın en/boy oranı gibi özellikler de yapısal parçanın burkulma dayanımını değişmektedir. Farklılık gösteren plaka özellikleri ve sınır koşullarından dolayı, yapısal parçalarda burkulmadan kaynaklı oluşabilecek hasarı göz önünde bulundurarak tasarımları boyutlandırmak havacılık endüstrisinde oldukça önemlidir. Yükleme türündeki farklılık ve yapı üzerinde delik olması durumu için farklı çalışmalar literatürde yer almaktadır. Tez kapsamında basit mesnetli ve sabit mesnetli sınır koşulları için basma ve kayma gerilimleri için sonlu elemanlar metodu ile iki boyutlu modeller oluşturarak analiz simülasyonları gerçekleştirilmiştir. İki boyutlu analiz simülasyonlarından burkulma katsayıları ve kritik burkulma yükleri elde edilmiştir. Gerçekleştilen çalışmada ayrıca diğer bir geometrik unsur olan konvansiyonel üretim yöntemleri ile üretilen parçalarda yer alan köşe radyus yarıçapının; delik çapı ve yapının en/boy oranı ile ilişkisi üç boyutlu sonlu elemanlar modeli kullanılarak incelenmiştir. Ek olarak parçanın çalışma koşullarında maruz kalacağı yük ve sınır koşullarına uygun daha hafif ve burkulma dayanımı açısından isterleri sağlayan radyus yarıçapı ve delik çapı boyut optimizasyonları gerçekleştirilmiştir.In the aviation industry and different sectors, holes are a frequently preferred geometric element in structural parts containing thin sections, such as lightening the structure, ease of access, and system requirements. Different characteristics, such as the hole's location on the structure, shape, number, size, and reinforcement on the hole edge, change the structure's strength and stress distribution on the structure. Along with geometric elements, features such as the type of loading applied to the structure, boundary conditions, and the plate's aspect ratio also change the structural parts' buckling strength. Due to these different plate properties and boundary conditions, it is essential to dimension the designs by considering the damage that may occur due to buckling in structural parts in the aviation industry. Different studies are available in the literature regarding the difference in the type of loading and the presence of holes on the structure. Within the thesis scope, buckling coefficients and critical buckling loads were obtained by performing analysis simulations with the two-dimensional finite element model method for compressive and shear stresses for simply supported and fixed supported boundary conditions. In the study carried out, the corner radius in the parts produced with conventional production methods, which is another geometric element; The relationship between the hole diameter and the structure's aspect ratio was examined using a three-dimensional finite element model. In addition, radius and hole diameter dimension optimizations that are lighter and meet the requirements in terms of buckling strength have been carried out by the load and boundary conditions that the part will be exposed to under operating conditions.Türk Havacılık ve Uzay Sanayii A.Ş. (TUSAŞ
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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