• Fashion & Textile Research Journal
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• v.11 no.2
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• pp.359-362
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• 2009

This study investigates the behavior of water vapor permeability of a layered system to find out a comfortable combination of a layered system for outdoor activities and examines the water vapor permeability of various types of outdoor clothing fabrics. The layered system includes the base layer such as sportswool and polyester/cotton fabrics, the middle layer such as single and double sided fleece fabrics, and the shell layer such as polyurethane-coated, PTFE-laminated and microfiber fabrics in this experiment. Results show that the layered system was applied, it was working together as a whole having some influence on each other layer, though every layer offered varying degree of water vapor permeability. Water vapor permeability of layered system exactly followed the same trend as the shell layer, which is all vapor permeable water repellent fabrics as a single layer. The rate of water vapor transfer through a layered system is mainly related to the type of vapor permeable water repellent fabrics used for the shell layer.

• Advances in concrete construction
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• v.14 no.1
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• pp.35-43
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• 2022

Based on novel Galerkin's technique, the theoretical study gives a prediction to estimate the vibrations of FG rotating cylindrical shell. Terms of ring supports have been introduced by a polynomial function. Three different laws of volume fraction are utilized for the vibration of cylindrical shells. Variation frequencies with the locations of ring supports have been analyzed and these ring supports are placed round the circumferential direction. The base of this approach is an approximate estimation of eigenvalues of proper functions which are the results of solutions of vibrating equation. Each longitudinal wave number corresponds to a particular boundary condition. The results are given in tabular and graphical forms. By increasing different value of height-to-radius ratio, the resulting backward and forward frequencies increase and frequencies decrease on increasing length-to-radius ratio. There is a new form of frequencies is obtained for different positions of ring supports, which is bell shaped. Moreover, on increasing the rotating speed, the backward frequencies increases and forward frequencies decreases.

• Steel and Composite Structures
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• v.36 no.4
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• pp.463-480
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• 2020

Although detailed shell analysis is suitable to predict the ductile crack initiation life of steel members, such detailed method adds time expense and complexity. In order to simply predict the ductile crack initiation life of stiffened steel bridge piers, a total of 33 cases are simulated to carry out the parametric analyses. In the analysis, the effects of the width-to-thickness ratio, slenderness ratio, plate thickness and so on are considered. Both shell analyses and beam analyses about these 33 cases are conducted. The plastic strain and damage index obtained from shell and beam analyses are compared. The modified factor β_s is determined based on the predicted results obtained from both shell and beam analyses in order to simulate the strain concentration at the base corner of the steel bridge piers. Finally, three experimental results are employed to verify the validity of the proposed method in this study.

• Fashion & Textile Research Journal
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• v.6 no.5
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• pp.648-654
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• 2004

The purpose of this study was to develops of brassiere pattern for middle school students (15 ages ${\mp}$ 3). In order to design a brassiere pattern, the body surface shell was used as the basic pattern. The foundation pattern and the four-piece brassiere pattern with wire were designed and sewed. The results of this study can be summarized as follows. 1. The foundation pattern of the size 75A was proved proper for the body by the wearing tests. Each angle and length of the parts on the base line of the breasts played an important role on setting the pattern. 2. As based on the body surface shell extracted from a plaster mold, the cups of brassiere pattern were applied to the body surface shell, and full side stretch -wings were applied to 8% reduced body size. 3. As the result of the wearing test, the excellence of the experimental brassiere was recognized objectively, with high marks in all the items of clothing compensation, body motion, clothing pressure and breasts growth. The experimental brassiere was covering the whole breasts to cope with change according to breasts growth, It was designed to support the breasts firmly, not to press the middle part of them. Simultaneously, this has the advantages that satisfy a characteristic of a figure and the purpose of putting it on.

• Steel and Composite Structures
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• v.10 no.4
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• pp.361-371
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• 2010

Enhancement in the seismic buckling capacity of steel tanks caused by the addition of fiber reinforced polymers (FRP) retrofit layers attached to the outer walls of the steel tank is investigated. Three-dimensional non-linear finite element modeling is utilized to perform such analysis considering non linear material properties and non-linear large deformation large strain analysis. FRP composites which possess high stiffness and high failure strength are used to reduce the steel hoop stress and consequently improve the tank capacity. A number of tanks with varying dimensions and shell thicknesses are examined using FRP composites added in symmetric layers attached to the outer surface of the steel shell. The FRP shows its effectiveness in carrying part of the hoop stresses along with the steel before steel yielding. Following steel yielding, the FRP restrains the outward bulging of the tank and continues to resist higher hoop stresses. The percentage improvement in the ultimate base moment capacity of the tank due to the addition of more FRP layers is shown to be as high as 60% for some tanks. The percentage of increase in the tank moment capacity is shown to be dependent on the ratio of the shell thickness to the tank radius (t/R). Finally a new methodology has been explained to calculate the location of Elephant foot buckling and consequently the best location of FRP application.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.31 no.3
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• pp.1-9
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• 2023

The overall Air Force's serious accident rate is decreasing, but the trainer's accident rate is on the rise from 0.24% in '00~'09 to 0.77% in '01~'19. Base on the SHELL model recommended by the ICAO, the risk factors of the introductory flight training course were analyzed, implications were examined, and safety promotion measures were proposed. A survey of 25 questions was organized based on regulations, guidelines, and related data for each component of the SHELL model in accordance with the introductory course of Air Force flight training. The survey was divided into a student group and instructor group and compared and analyzed into L-L, L-S, L-H, and L-E based on the results after conducting it, and implications for this were derived. Compared to other analysis factors, L-L showed that the average of the instructor group was relatively higher that of the student group in all questions.

• Korean Journal of Computational Design and Engineering
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• v.5 no.1
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• pp.1-11
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• 2000

The purpose of Computer Aided Design is to design good products as quickly as possible. To do this, it is important to reuse the old designs and build on them. Most engineering designers, therefore. hale studied methods for reusing old designs, and the results of their study hale been applied to new designs Unfortunately, this only involves reuse of geometric data without design knowledge. If they can design products with the geometric data, including design knowledge, of the old designed and share them through the Internet, design efficiency will be improved. In other words, one way to improve designer's productivity is to share design information that includes knowledge and scattered data across design offices. This paper introduces a shared design environment with distributed knowledge-base. A product design environment based on distributed knowledge-base is proposed, which integrates the CORBA, OLE and WWW as the network architecture, a 3D CAD system, and an expert system shell. A design example of the lens barrel of a projection television is implemented to verify the idea.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.1
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• pp.90-96
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• 2011

The shock absorber base assembly is one of the parts in the shock absorber equipment that controls the vehicle movement. It absorbs the shock and vibration to guarantee riding stability and comfort. It demands strength, reliability and strict airtightness of the welded section because the shock absorber base assembly is a container which resists pressure and needs durability by being filled with gas and oil. However, the current engineering needs a lot of production time, has a high cost and shows a low production rate. These problem due to the eight production processes, four of which are spot welding, reinforcement welding like metal active welding (MAG), prior process of the base assembly cap and tube for precision and pressing. We will analyze the manufacturing processes of the base assembly and suggest an improved manufacturing method that uses frictional welding. The results will show that the new method of the frictional welding is better than the previous welding technique. Through the use of this concept of frictional welding, the welding conjunction will be strengthened, measurements will be more precise, and the cost and the number of processes will be reduced.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.2 no.1
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• pp.42-51
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• 1972

Nine DETERGENT base materials have been examined in a series of in vivo and in vitro TESTS involving the use of HUMAn SKIN and various ANIMAL SKINS. Lack of agreement between the results from different tests was apparent and cautious approach to predictive SKIN-IRRITANCY testing with detergents is advocated.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.2
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• pp.25-34
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• 2003

In the present paper, formulation of a nine-node assumed strain shell element is modified and extended for analysis of actuator embedded/attached structures. The shell element can alleviate locking and has sic DOFs per node by discarding assumption of no thickness change. In modeling of the physicalquantities, we have assumed linear strain field through the whole thickness direction. The electric and mechanical quantities have been coupled through the constitutive equations. Unlike typical shell element, the present shell element allows thickness change. Thus, three-dimensional piezoelasticity can be accurately simulated. Base on the formulation, a finite element program is generated and the code is validated by solving numerical examples. The results from the present work are well agreed with those from other references.