Accelerating Translational Image Registration for HDR Images on GPU

High Dynamic Range (HDR) images are generated using multiple exposures of a scene. When a hand-held camera is used to capture a static scene, these images need to be aligned by globally shifting each image in both dimensions. For a fast and robust alignment, the shift amount is commonly calculated using Median Threshold Bitmaps (MTB) and creating an image pyramid. In this study, we optimize these computations using a parallel processing approach utilizing GPU. Experimental evaluation shows that the proposed implementation achieves a speed-up of up to 6.24 times over the baseline multi-threaded CPU implementation on the alignment of one image pair. The source code is available at https://github.com/kadircenk/WardMTBCudaComment: Submitted for Consideration for Publication in High Performance Computing Conference 202

Seven Years of Retention of Severe Mandibular Prognathism Treated With Bimaxillary Surgery: Two Case Reports

These case reports describe the surgical treatment of 2 male adult patients with severe mandibular prognathism. For both patients, anterior repositioning of the maxilla by Le Fort I osteotomies with and without impaction and mandibular posterior repositioning by sagittal split ramus osteotomies were performed. The aim of this case report is to identify successfully treated surgical cases maintaining the results throughout the follow-up period of 7 years

Creep modelling of polypropylenes using artificial neural networks trained with Bee algorithms

Polymeric materials, being capable of high mouldability, usability of long lifetime up to 50 years and availability at low cost properties compared to metallic materials, are in demand but finite element-based design engineers have limited means in terms of the limited material data and mathematical models. In particular, in the analysis of products with complex geometry, the stresses and strains of various amounts formed in the product should be known and evaluated in terms of a precise design of the product to fulfil life expectancy. Due to time and cost constraints, experimental data cannot be available for all cases required in analysis, therefore, finite element method-based simulations are commonly used by design engineers. This is also computationally expensive and requires a simpler and more precise way to complete the design more realistically. In this study, the whole creep behaviour of polypropylene for all stresses were obtained with 10% accuracy errors by artificial neural networks trained using existing experimental test results of the materials for a particular working range. The artificial neural network model was trained with traditional as well as heuristic based methods. It is demonstrated that heuristically trained ANN models have provided much accurate and precise results, which are in line with 10% accuracy of experimental data

Yapıştırıcı bağlı silindirik bindirme bağlantılarda gerilme analizi

Bu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır

Sonlu eleman gerilme analizinde fuzzy mantığı

Bu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır.Fuzzy mantığı, Sonlu eleman, Gerilme analizi, Yapıştırıcı bağlantılar SONLU ELEMAN GERİLME ANALİZİNDE FUZZY MANTIĞI Eskiden, yapının emniyetini garantiye alan tek şey sorumlu ustanın tecrübesiydi. Ancak, bu yüzyıl boyunca mühendislik uygulamalarından elde edilen tecrübe emniyet bölgesinin sınırlarını belirlemenin temelini oluşturmuştur. Şimdi ise mühendis, fuzzy küme teorisi sayesinde, bu tecrübeyi analizde kullanabilmektedir. Bu çalışmada amaç, sonlu eleman gerilme analizinde fuzzy mantığı kullanılmasına imkan veren yeni bir malzeme matrisi tanımlamak ve bu matris sayesinde tek bindirme yapıştırıcı bağlantının fuzzy sonlu eleman gerilme analizini gerçekleştirmektir. Matris, sonlu eleman gerilme analizinde kullanıldığında alt ve üst sımr yerdeğiştirmeleri verecek şekilde tanımlanmıştır. Malzemelere ait mühendislik sabitlerinde bulunan belirsizlikleri hesaba katmak amacıyla, fuzzy küme teorisine dayanan yeni bir model sunulmuştur. Verilen bu modelde, zorlanma-gerilme matrisindeki elastisite modülü ve Poisson oram fuzzy sayılar olarak alınmıştır. Fuzzy sayılan, üçgen üyelik fonksiyonları ve ^--üyelik fonksiyonları kullanılarak modellenmiştir. Tanımlanan bu matris tek bindirme yapıştırıcı bağlantının fuzzy sonlu eleman gerilme analizinde kullanılmıştır. Yapıştırıcı bölgesinde seçilen bir noktada, düzlem yerdeğiştirme bileşenlerinin, düzlem gerilme bileşenlerinin ve von Mises gerilmesinin mümkün dağılımları grafiklerle gösterilmiştir. Ayrıca, bağlantıda eşdeğer gerilmenin maksimum olduğu Gauss noktasında von Mises gerilmesinin mümkün dağılımları verilmiştir. Sonlu eleman ağından kaynaklanan hatalar dikkate alınıp, fuzzy mantığında çıkarım kuralı kullanılarak sonlu eleman sonuçlarına ait toplam üyelik fonksiyonu elde edilmiştir. Son olarak, üyelik derecelerinin filtrelenmesine ilişkin bir yöntem gösterilmiştir.Keywords: Fuzzy logic, Finite element, Stress analysis, Adhesive joints. FUZZY LOGIC IN THE FINITE ELEMENT STRESS ANALYSIS In the old days the experience of master builders guaranteed the safety of structures. During this century the experience obtained from practising engineering created the basis for the use of safety margins. By means of fuzzy set theory, now, the engineer could use the experience in the analysis. The aim of this study is to define a new material matrix for fuzzy finite element stress analysis and by using the matrix to carry out fuzzy finite element stress analysis of adhesively bonded single lap joint. The material matrix is defined such a way that it gives the bound of displacements when it is used in the finite element stress analysis. A new model based on theory of fuzzy sets is presented. It takes the uncertainty into account for the engineering constants of the joint materials. In the model given, elasticity modulus and Poisson's ratio are taken as two fuzzy numbers in the strain- stress matrix. Fuzzy numbers are modelled by using triangular membership functions and extended ^-functions. The material matrix, then, can be used in the fuzzy finite element stress analysis of adhesively bonded single lap joint. At a selected point in the adhesive layer, possibility distribution of displacement components, plane stress components and von Mises stress are depicted by graphics. At the Gauss point where maximum von Mises stress value appears, possibility distributions of von Mises stress are also given. By means of a fuzzy inference scheme, total membership function of the finite element results are determined by considering the estimated error resulting from the mesh discretization. Lastly, a method for filtering the element grades is introduced. XVI

EFFECT OF RIM THICKNESS ON THE ROOT STRESSES OF SPUR GEAR TOOTH

In this study, root stresses of spur gear tooth are analysed as plane stress problem by the finite element method (FEM). The effects of rim thickness of spur gear on the root stresses is investigated. The computer program which produces a profile of the gear tooth for obtaining mesh region presenting the problem is prepared. In order to examine the effect of the rim thickness on the root stresses, the stress analysis is made on single tooth models varying the rim thickness in steps. On the basis of these investigations a suitable rim thickness of gear model for stress analysis by FEM is proposed

A METHOD FOR STIFFNESS MATRIX OF TRIANGULAR TORUS ELEMENT

The matrices of constants for the stiffness matrices of triangular torus elements family are generated on computer by using the expression given in literature. After the matrices are generated once, it is easy to obtain the stiffness matrices for all member of family of triangular torus elements without need for numerical integration

Torsional Stresses in the Transverse Fillet Weld Tubular Joints

Torsional stresses, τrθ and τθz, in the transverse fillet tubular weld joint subjected to torsional load have been analyzed by the finite element method using triangular and quadrilateral izoparametric axisymmetric fourier type torus finite elements. There is an axisymmetry with respect to geometry and material properties but no axisymmetry with respect to the loading. With respect to material properties, two kinds of joints are considered in the study. One consists of steel tubes and steel weld material, the other steel tubes and brass weld material. All of the materials used are assumed linear-elastic. Changing the torsional stresses, along the weld legs and the weld throat, are plotted in dimensionless coordinates

The Effects of Addendum Modification Coefficient on Tooth Stresses of Spur Gear

The effects of addendum modification coefficient on the root stresses of spur gear are investigated. By considering positive and negative addendum modificated gears, distributions of root stresses are determined by the finite element method. The root stresses of addendum modificated gears are compared with those of standard gears. The problem is analyzed as one in the plane stress and, also the plane strain

Efficiency and safety of phenylephrine and tropicamide used in premature retinopathy: A prospective observational study

Background: To determine effects and side effects of topical application of phenylephrine 2.5% and tropicamide 0.5% combination in preterm infants. Methods: In this prospective observational study, 60 infants undergoing retinopathy of prematurity (ROP) screening were prospectively observed. Pupillary diameter, blood pressure, heart rate, and oxygen saturation were monitored before and after up to 24 h during ROP screening examinations. Results: The mean pupillary diameter 1 h after the instillation of drops was 5.58 ± 0.75 mm for both eyes. The mean systolic and diastolic pressure and oxygen saturation of infants did not change statistically until the end of the study. The average heart rate decreased by a mean of 4.96 beats/minute from the baseline following eye drops instillation. General condition deterioration, fall in oxygen saturation and bradycardia were observed in 4 infants that already had respiratory distress syndrome. Conclusion: The phenylephrine 2.5% plus tropicamide 0.5% drop is effective and safe as mydriatic combination for retinopathy of prematurity screening. In infants with an additional systemic disease such as respiratory distress syndrome, the side effects of mydriatic drops may be more common. Such babies should be kept under close observation. Trial registration: The trial was retrospectively registered on 28 February 2018. The ClinicalTrials.gov Identifier is NCT03448640. © 2019 The Author(s)