• Title/Summary/Keyword: ease lengths

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Bond strength characterization and estimation of steel fibre reinforced polymer - concrete composites

  • Jahangir, Hashem;Eidgahee, Danial Rezazadeh;Esfahani, Mohammad Reza
    • Steel and Composite Structures
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    • v.44 no.6
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    • pp.803-816
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    • 2022
  • Composite materials are effective in forming externally bonded reinforcements which find applications related to existing structures repair, attributed to their high strength-to-weight ratio and ease of installation. Among various composites, fibre reinforced polymers (FRP) have somewhat been largely accepted as a commonly utilized composite for such purposes. It is only recently that steel fibres have been considered as additional members of the FRP fibre family, intuitively termed as steel reinforced polymer (SRP). Owing to its low cost and permissibility of fibre bending at sharp corners, SRP is rapidly becoming a viable contender to other FRP systems. This paper investigates the bond behaviour of SRP-concrete joints with different bonded lengths (50, 75, 100, 150 and 300 mm) and widths (15, 30, 40, 50, and 75 mm) using single-lap shear tests. The experimental specimens contain SRP strips with a fixed density of steel fibres (0.472 cords/mm) bonded to the face of concrete prisms. The load responses were obtained and compared in terms of corresponding load and slip boundaries of the constant region and the peak loads. The failure modes of SRP composites are discussed, and the range of effective bonded length is evaluated herein. In the end, a new analytical model was proposed to estimate the SRP-concrete bond strength using a genetic algorithm, which outperforms 22 existing FRP-concrete bond strength models.

Investigation of damaged formwork timber beam retrofitting with anchoraged CFRP strip under different loading

  • Abdullah TURER;Ozgur ANIL;Abdulkadir CEVIK;R. Tugrul Erdem
    • Steel and Composite Structures
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    • v.50 no.6
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    • pp.689-703
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    • 2024
  • Construction of high-rise structures, formwork systems that can be installed quickly, resistant to external loads, can be used more than once, have become a necessity. Timber and composite timber materials are preferred in the formation of such formwork systems due to their durability, ease of assembly, light weight and easy to use more than one time. Formwork beams are the most commonly used structural component in the formation of such formwork systems, and these beams can be damaged for different reasons during their lifetime. In this study, H20 top P type timber formwork beams with 1800 and 2450 mm length which is among the products of DOKA(c) company is damaged under the effect of static loading up to a high load level of 85% of the maximum ultimate capacity and after being retrofitted using anchored CFRP strips, performance and behavior of the beams under the influence of various loading types such as static, fatigue and impact are investigated experimentally. Two different lengths of retrofitted timber formwork beams were tested by applying monotonic static, fatigue and impact loading and comments were made about the effects of the retrofit method on performance under different loading types.

The Effect of Base Projecting Walls on the Bearing Capacity and Settlement of Shallow Foundations on Soft Ground (저면돌출벽을 이용한 연약지반상 얕은기초의 지내력 증대 효과)

  • Lim, Jongseok;Park, Seunghoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.4
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    • pp.1523-1528
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    • 2013
  • It is necessary to develop the simple and efficient technique that ease entry of man and equipment and take the role of foundations of temporary or small structures on the soft ground. This study intends to verify the effects on the increase of bearing capacity of base projecting walls under shallow foundations and to investigate the variance of the bearing capacity of the foundations according to the interval and length of the walls. For this, model soft ground in the chamber equipped with loading apparatus is made and the loading tests on the model foundations with base projecting walls of various intervals and lengths using the apparatus are performed with measuring the loads and settlements. The results show that the base projecting walls under shallow foundations on soft ground are effective on the increase of bearing capacity and the more the number and length of the walls the larger the effects. And, when the ratio of interval to length of the walls is 1, i.e. the shape forming the base of the foundation and the walls is square, the bearing capacity is increased by 25% and the effect is optimum.

Genetic Characteristics of 207 Microsatellite Markers in the Korean Population and in other Asian Populations

  • Choi, Su-Jin;Song, Hye-Kyung;Jeong, Jae-Hwan;Jeon, In-Ho;Yoon, Ho-Sung;Chung, Ki Wha;Won, Yong-Jin;Choi, Je-Yong;Kim, Un-Kyung
    • Molecules and Cells
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    • v.25 no.2
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    • pp.301-304
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    • 2008
  • Microsatellites, short tandem repeats, are useful markers for genetic analysis because of their high frequency of occurrence over the genome, high information content due to variable repeat lengths, and ease of typing. To establish a panel of microsatellite markers useful for genetic studies of the Korean population, the allele frequencies and heterozygosities of 207 microsatellite markers in 119 unrelated Korean, Indian and Pakistani individuals were compared. The average heterozygosity of the Korean population was 0.71, similar to that of the Indian and Pakistani populations. More than 80% of the markers showed heterozygosity of over 0.6 and were valuable as genetic markers for genome-wide screening for disease susceptibility loci in these populations. To identify the allelic distributions of the multilocus genetic data from these microsatellite markers, the population structures were assessed by clustering. These markers supported, with the most probability, three clustering groups corresponding to the three geographical populations. When we assumed only two hypothetical clusters (K), the Korean population was separate from the others, suggesting a relatively deep divergence of the Korean population. The present 207 microsatellite markers appear to reflect the historical and geographical origins of the different populations as well as displaying a similar degree of variation to that seen in previously published genetic data. Thus, these markers will be useful as a reference for human genetic studies on Asians.

Pattern Analysis and Determination of Body Dimension for Flight Suit Design (비행복 설계를 위한 패턴 분석 및 인체치수 설정)

  • Jeon, Eun-Jin;Park, Ji-Eun;Jeong, Jeong-Rim;Park, Sei-Kwon;Park, Jang-Un;You, Hee-Cheon;Kim, Hee-Eun
    • Fashion & Textile Research Journal
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    • v.11 no.2
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    • pp.286-292
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    • 2009
  • The purpose of this study is to analyze the pattern of the present flight suit, to select variables of human body and key dimensions for making pattern of the flight suit, and to decide the most appropriate size of human body and rate of ease for designing an overall flight suit. For analyzing the pattern of flight suit, we used "M95Special" (men ; chest circumference 92-97 cm ; height : above 177 cm), which was indicated as the standard of the Ministry of National Defense. We analyzed general appearance and the actual dimensions of the pattern of the flight suit. As a result of analyzing the pattern, flight suit was front-opened overall style which had a flat collar with rounded edges, two-pieced sleeves with lower height of the sleeve's cap, 3cm-width belt on the waist and 8 pockets. To decide the most appropriate size of human body, we selected 20 variables of human body in the 359 variables of the Size Korea by referring the previous studies. The 20 variables of human body were 9 circumferences (chest, waist, hip, neck, armscye, wrist, thigh, knee, and ankle), 9 lengths (stature, back interscye fold, waist back, crotch height, crotch, body rise, arm, outside leg and total), and 2 breadths (biacromial and chest). We drew out the size of 20 variables from the Size Korea and US Army anthropometry data and decided the most appropriate values from the drawn data for applying to the pattern of flight suit.

A Study on the Pattern Grading for School Boys (학령기 남아 예복의 그레이딩에 관한 연구)

  • Han, Jin-Yee;Jo, Jin-Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.8 s.145
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    • pp.1146-1157
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    • 2005
  • As individual family has fewer children, market sectors targeting children's goods upgrade their products quality and price. Children's wear used to be for casual activity or going to school. Recently, occasions in which children are dressed up are getting increase, such as wedding, concert or family gathering. Therefore, the industry sector of formal wears for school boys are growing. The purpose of this study is to research and grading of formal wears for school boys to improve their fit and comfort. The selected items as formal wear were tailored jacket, tuxedo, tail coat and pants. Based on the grading increments of the industry, grading was done far 7 years and 11 years old school boy for each item. Like the pattern alteration, grading increments were tested and altered through wearing tests. The final increments were suggested as the 'researched grading increments'. The results and conclusions are: 1. Appropriate size allowance, ease amount and lengths for boys are different from those far adults. The difference should be applied for boy's wear. 2. Grading increments for an age group are different from other age group. For example increments of 7 from 9 are different from that of 11 from 9. It is because a certain part grows faster during a certain age whereas other part grows faster during different period. Therefore grading for children should reflect their growth rather than same size increments which is common in adult size chart.

Development and validation of a non-linear k-ε model for flow over a full-scale building

  • Wright, N.G.;Easom, G.J.;Hoxey, R.J.
    • Wind and Structures
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    • v.4 no.3
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    • pp.177-196
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    • 2001
  • At present the most popular turbulence models used for engineering solutions to flow problems are the $k-{\varepsilon}$ and Reynolds stress models. The shortcoming of these models based on the isotropic eddy viscosity concept and Reynolds averaging in flow fields of the type found in the field of Wind Engineering are well documented. In view of these shortcomings this paper presents the implementation of a non-linear model and its evaluation for flow around a building. Tests were undertaken using the classical bluff body shape, a surface mounted cube, with orientations both normal and skewed at $45^{\circ}$ to the incident wind. Full-scale investigations have been undertaken at the Silsoe Research Institute with a 6 m surface mounted cube and a fetch of roughness height equal to 0.01 m. All tests were originally undertaken for a number of turbulence models including the standard, RNG and MMK $k-{\varepsilon}$ models and the differential stress model. The sensitivity of the CFD results to a number of solver parameters was tested. The accuracy of the turbulence model used was deduced by comparison to the full-scale predicted roof and wake recirculation zone lengths. Mean values of the predicted pressure coefficients were used to further validate the turbulence models. Preliminary comparisons have also been made with available published experimental and large eddy simulation data. Initial investigations suggested that a suitable turbulence model should be able to model the anisotropy of turbulent flow such as the Reynolds stress model whilst maintaining the ease of use and computational stability of the two equations models. Therefore development work concentrated on non-linear quadratic and cubic expansions of the Boussinesq eddy viscosity assumption. Comparisons of these with models based on an isotropic assumption are presented along with comparisons with measured data.

Comparison of Deep Learning Frameworks: About Theano, Tensorflow, and Cognitive Toolkit (딥러닝 프레임워크의 비교: 티아노, 텐서플로, CNTK를 중심으로)

  • Chung, Yeojin;Ahn, SungMahn;Yang, Jiheon;Lee, Jaejoon
    • Journal of Intelligence and Information Systems
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    • v.23 no.2
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    • pp.1-17
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    • 2017
  • The deep learning framework is software designed to help develop deep learning models. Some of its important functions include "automatic differentiation" and "utilization of GPU". The list of popular deep learning framework includes Caffe (BVLC) and Theano (University of Montreal). And recently, Microsoft's deep learning framework, Microsoft Cognitive Toolkit, was released as open-source license, following Google's Tensorflow a year earlier. The early deep learning frameworks have been developed mainly for research at universities. Beginning with the inception of Tensorflow, however, it seems that companies such as Microsoft and Facebook have started to join the competition of framework development. Given the trend, Google and other companies are expected to continue investing in the deep learning framework to bring forward the initiative in the artificial intelligence business. From this point of view, we think it is a good time to compare some of deep learning frameworks. So we compare three deep learning frameworks which can be used as a Python library. Those are Google's Tensorflow, Microsoft's CNTK, and Theano which is sort of a predecessor of the preceding two. The most common and important function of deep learning frameworks is the ability to perform automatic differentiation. Basically all the mathematical expressions of deep learning models can be represented as computational graphs, which consist of nodes and edges. Partial derivatives on each edge of a computational graph can then be obtained. With the partial derivatives, we can let software compute differentiation of any node with respect to any variable by utilizing chain rule of Calculus. First of all, the convenience of coding is in the order of CNTK, Tensorflow, and Theano. The criterion is simply based on the lengths of the codes and the learning curve and the ease of coding are not the main concern. According to the criteria, Theano was the most difficult to implement with, and CNTK and Tensorflow were somewhat easier. With Tensorflow, we need to define weight variables and biases explicitly. The reason that CNTK and Tensorflow are easier to implement with is that those frameworks provide us with more abstraction than Theano. We, however, need to mention that low-level coding is not always bad. It gives us flexibility of coding. With the low-level coding such as in Theano, we can implement and test any new deep learning models or any new search methods that we can think of. The assessment of the execution speed of each framework is that there is not meaningful difference. According to the experiment, execution speeds of Theano and Tensorflow are very similar, although the experiment was limited to a CNN model. In the case of CNTK, the experimental environment was not maintained as the same. The code written in CNTK has to be run in PC environment without GPU where codes execute as much as 50 times slower than with GPU. But we concluded that the difference of execution speed was within the range of variation caused by the different hardware setup. In this study, we compared three types of deep learning framework: Theano, Tensorflow, and CNTK. According to Wikipedia, there are 12 available deep learning frameworks. And 15 different attributes differentiate each framework. Some of the important attributes would include interface language (Python, C ++, Java, etc.) and the availability of libraries on various deep learning models such as CNN, RNN, DBN, and etc. And if a user implements a large scale deep learning model, it will also be important to support multiple GPU or multiple servers. Also, if you are learning the deep learning model, it would also be important if there are enough examples and references.

A Study on the Women's Bodysuit Sleeve Block Construction Using Stretch fabrics (Stretch 소재를 사용한 여성용 Bodysuit Sleeve 원형 설계에 관한 연구)

  • Park Gin-Ah
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.12 s.148
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    • pp.1535-1545
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    • 2005
  • The study aimed firstly, to develop the women's bodysuit sleeve block construction method adopting the appropriate pattern reduction rates according to the fabric stretch property. Secondly, the details applied to the bodysuit sleeve block drafting (Dr the educational and industrial usage were proposed. For these, several distinguishing bodysuit sleeve pattern making methods(i.e. Joseph-Armstrong: T1, Shoben & Ward: T2, Esmod: T3 and Mixed Joseph-Armstrong: T4) were analyzed and divided into two categories that adopt 1) the equally (i.e., T1) and 2) the differently(i.e., T2, T3 & T4) distributed front and back armhole length measurements. Women's sleeve samples were made for the research using the same stretch fabric($50\%\;and\; 70\%$ in wale and course each) to the previous research. A group comprising 5 relevant experts evaluated the fit and comfort features of the samples. Experiments analyzed the appearance of sleeve samples focused on total 13 evaluation parts(including the front/side/back fit tolerance, sleeve centre line, sleeve length, appropriateness of the sleeve appearance balanced with the bodysuit and etc.): and performed the comfort test evaluating three kinds(vertical-front/vertical-side/ horizontal) of arm movements. The most appropriate bodysuit sleeve to fulfil the original aims of the study was suggested. The findings and suggestions throughout the study were: 1) the measurements and required reduction rates for the bodysuit sleeve block developed: outer sleeve length (with 1.0 RR), crown height(with 0.7 RR), front and back armhole lengths measured on the bodysuit blocks ($0\%$ ease amount), elbow width(0.9/0.95 RR), wrist girth measurements(from $12\%\;to\;18\%$ tolerances can be given to): and 2) the differently distributed front and back armhole length measurements resulted in the better fit and comfort through the research.