• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1188-1195
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• 2007

The vertical forces in rail fasteners at areas of bridge transitions near the embankment and on the pier will occur due to different deformations of adjoining bridges caused by the trainloads, the settlement of supports, and the temperature gradients. The up-lifting forces is not large problem in the blast track because the elasticity of blast and rail pad buffs up-lifting effect. But, it is likely to be difficult to ensure the serviceability of the railway and the safety of the fastener in the end in that concrete slab track consist of rail, fastener, and track in a single body, delivering directly the up-lifting force to the fastener if the deck is bended because of various load cases, such as the end rotation of the overhang due to the vertical load, the bending of pier due to acceleration/braking force and temperature deviation, the settlement of embankment and pier, the temperature deviation of up-down deck and front-back pier, and the rail deformation due to wheel loads. The analysis of the rail fastener is made to verify the superposed tension forces in the rail fastener due to various load cases, temperature gradients and settlement of supports. The potential critical fasteners with the highest uplift forces are the fastener adjacent to the civil joint. The main influence factors are the geometry of the bridge such as, the beneath length of overhang, relative position of bridge bearing and fastener, deflection of bridge and the vertical spring stiffness of the fastener.

• 소성∙가공
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• 제18권4호
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• pp.336-341
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• 2009

Hydroformed parts have higher dimensional accuracy, structural strength, and dimensional repeatability. Particularly in the automotive industry, manufacturing of parts with complex shapes from tubular materials sometimes requires one or more pre-forming operations such as bending before the hydroforming process. The pre-bending process is an important process for the successful hydroforming in the case where the perimeter of the blank is nearly the same as that of final product. The bendability of a tube depends on the parameters such as the bending radius, welding methods, mechanical properties and hardness. Through the stainless steel tubes bent by rotary draw bending machine, this study shows the following : (1) The influence on spring back ratio variation with stress level in the welded bent tube. (2) The Cross-section ovality variation with weld seam position and bending radius. (3) The relation between elongation and thickness reduction of tension zone with weld seam position and bending radius. (4) Workability evaluation of bent stainless steel tubes through the hardness of materials and hardness increment. The results of this study may help to understanding of characteristics on bendability of stainless steel tubes.

• 한국생산제조학회지
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• 제24권3호
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• pp.342-347
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• 2015

The launcher pod for missiles capable of carrying a range of different warheads has been designed to be mounted on the tracked vehicle of the hybrid weapon system (HWS). In the development of this launcher pod, its structure was designed to be resilient to damage caused by shock and vibration, as well as preventing assembly errors due to the spring-back of the main composite cover and interfacing parts. This study investigated the design of the newly developed launcher pod, with its hybrid composite-metal structure, through simulation and experiment. Both simulation and actual experiments showed that the structure of the launcher is resilient to vibration and shock. The launcher pod was also subjected to vibration and shock tests to verify its performance.

• 한국식생활문화학회지
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• 제32권5호
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• pp.333-360
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• 2017

This study aims to examine the contents of "Juchochimjeobang", a cookbook about Jeotgal kimchi, and review its value in the history. This cookbook was published between about 1500s and early 1600s, and its book title is unknown because both the front and the back covers thereof are missing. However, the cookbook contains many wine and kimchi recipes, accounting for 66%, and "Juchochimjeobang" was thus named after the recipes. "Juchochimjeobang" has 126 recipes in 120 categories, and this study examines 20 kimchi recipes and 7 recipes for preserving vegetables. "Juchochimjeobang" has a specific recipe for making Jahajeot and Baekajeot kimchi which are described in literature published between 1400s and 1500s. Although the recipes for making the aforementioned two types of Jeotgal kimchi are simple because jeotgal is just mixed with main materials, they are different from the recipe for Seokbakji described in Gyuhapchongseo, a cookbook written in the 19th-century Joseon Dynasty. Seokbakji described in Gyuhapchongseo is made by mixing spices of ginger, spring onion, chili powder with other materials. This implies changes of making Seokbakji over time. Moreover, "Juchochimjeobang" is a very valuable historical cookbook because it has unique recipes, for example, adding sesame liquid, chinese pepper, willow and the like.

• 소성∙가공
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• 제17권8호
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• pp.570-578
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• 2008

A flexible forming apparatus is composed a number of punches which have spherical pin tip shape instead of conventional solid die. The flexible forming tool consisted of punch array in a matrix form was proposed as an alternative forming method to substitute the conventional line heating method which use heat source to induce residual stress along specified heating lines. In this study, application of the flexible forming process to the small scale curved plate forming was conducted. Numerical simulations for both solid and flexible die forming process were carried out to compare the shape of the products between flexible and conventional die forming process. In addition, spring-back analysis was conducted to figure out the feasibility of the flexible forming process comparing with the die forming process in view of final configuration of the specimens. Moreover, experiment was also carried out to confirm the formability of the process. Consequently, it was confirmed that the flexible die forming method has capability and feasibility to manufacture the curved plates for shipbuilding.

• 한국자동차공학회논문집
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• 제8권3호
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• pp.171-180
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• 2000

This paper deals with the whole-body vibration and ride quality evaluation in the vertical direction. The responses of the floor, hip, back, and head in four subjects were measured for various seats when the floor was excited by random vibration with r.m.s of 1.2m/s2 in the vertical direction. In the transmissibility between the hip and floor, the fundamental mode is observed at 4.4 Hz. In the transmissibility between the head and floor, the fundamental mode at 4.4Hz and the second mode at 7.6Hz are observed. It is shown that the head motion is 41% larger than the hip motion and the response of female subject is larger than that of male subject. The response without backrest also was compared with that with backrest. From these human responses ride quality of five seats were evaluated by the ride value such as transfer ration having frequency weighting function is the statistical sense. It is observed that the seat having high damping property can reduce the most acceleration exposed to hip in the statistical sense for all ride valves, while the seat having different seat spring doesn't show statistical difference.

• 아태비즈니스연구
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• 제8권2호
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• pp.41-55
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• 2017

This exploratory research compares two particular features of coffee culture, namely the reason why a particular coffee shop is frequented and the reason for going to the chosen coffee shop in Italy and South Korea. A survey was carried out targeted at current undergraduate university students in both countries with data being collected in the late spring and early summer of 2017. The main impetus for this research was to investigate the aforementioned areas given the fact that Italy has such a long standing coffee culture that dates back centuries and is still an industry dominated by independent coffee houses while the Korean coffee industry started developing in the early 1980s and taking off after the 1988 Olympic Games. The Korean coffee industry, in contrast, is driven by the franchise coffee shops such as Starbucks, $Caf{\acute{e}}$ Benne, and The Coffee Bean among others. While both countries have well developed coffee cultures, they developed along very different lines. Data collected from respondents are tabulated and presented followed by an analysis and interpretation of the data. Finally, some suggestions on how to conduct further research in order to better understanding the underpinnings and contributing factors in understanding consumer choice and coffee culture in both Italian and Korea are suggested.

• 복식문화연구
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• 제2권1호
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• pp.123-143
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• 1994

The aim of this research analyze women's preference in types and formation of skirt lines by their ages and body shapes. The aim of this study is for women to select clothing which can cover their shortcomings and to present the practical and positive data about skirt design to clothing maker. The results of this research are summarized as followed : Tight skirt is the beest preferred and flare is the next. Narred silhouettes re preferred about th width of each kind of skirt, but as for the gored and flare skirts middle-width silhouettes are preferred. Preferred lengths of the skirts are different from ages; the middle like minilines, the thirties like miniline, the thirties and the forties natural line, and the fifties midiline, and according to body shapes, the skinny or standard shape like natural line and the fat midiline. All age prefer natural waist line, and twenties and the skinny like high waist line and belt compared to fifties and the fat. All ages like dart-treated skirt waist and wrinkle-decoration with narrow vertical lines or tuck-decoration with narrow horizontal line. White and blue are preferred colors of skirts in spring and summer, the skinny and the standard like blue, whereas the fat like black. All ages like soft materials and one-colored skirts without patterns Adult women like jipper to open waist of a skirt. Most of them like back positioned one, but fifties and the fat prefer side positioned ones.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.158-163
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• 2009

Titanium alloy sheets have excellent specific strength and corrosion resistance as well as good performance at high temperature. Recently, titanium alloys are widely employed not only aerospace parts but also bio prothesis and motorcycle. However, due to the low formability and large spring back at room temperature, titanium alloy sheets were usually formed by slow forming or hot forming with heating die and specimen. In the sheet metal forming area, FE simulation technique to optimize forming process is widely used. To achieve high accuracy FE simulation results, Identification of material properties and deformation characteristic such as yield function are very important. In this study, uniaxial tensile and biaxial tensile test of Ti-6Al-4V alloy sheet with thickness of 1.0mm were performed at elevated temperature of 873k. Biaxial tensile tests with cruciform specimen were performed until the specimen was breakdown to characterize the yield locus of Ti-6Al-4V alloy sheet. The experimental results for yield locus are compared with the theoretical predictions based on Von Mises, Hill, Logan-Hosford, and Balat's model. Among these Logan-Hosford's yield criterion well predicts the experimental results.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.310-313
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• 2007

In roll forming process, a sheet metal is continuously progressively formed into a product with required cross-section and longitudinal shape, such as a circular tube with required diameter, wall-thickness and straightness, by passing through a series of forming rolls in arranged in tandem. In this process, each pair of forming rolls installed in a forming machine play a particular role in making up the required cross-section and longitudinal shape of the product. In recent years, that process is often applied to the bumper rail in the automotive industries. In this study, a optimal roll flower model and proper roll-pass sequence can be suggested by analyzing courcenter strain and longitudinal strain according to the roll-pass with FEM simulation. And also effects of the process parameters on the final shape formed by roll forming defects a evaluated.