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Parametric Study on Properties of bridge by CWR(Continuous Welded Rail) and Bridge Interaction Analysis (장대레일과 교량의 상호작용 해석을 통한 교량제원 매개변수 분석)

  • Kim, Jong-Min;Han, Sang-Yun;Lim, Nam-Hyoung;Kang, Young-Jong
    • Proceedings of the KSR Conference
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    • 한국철도학회 2007년도 춘계학술대회 논문집
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    • pp.1460-1465
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    • 2007
  • CWR(Continuous Welded Rail) and bridge interaction produce rail force, bridge displacement and rail/bridge relative displacement. Each of these has limitation by many codes. In this paper, analysis of interaction has been carried out by using foreign codes(UIC 774-3 R code of Europe etc.) because there is no code about interaction between rail and bridge in Korea. Recently, railway bridges with CWR has been constructed for structural and economical reasons. When designer plans railway bridges, design a bridge model first and then investigate railway forces and displacement by interaction analysis. If these results go out bounds from limitation, designer plans railway bridges again and again. In this paper, using the parametric study on CWR and railway bridge interaction, railway bridge parameters such as length of bridge span, area of bridge, moment of inertia, stiffness of pier, etc. are presented. It helps preliminary design of railway bridges.

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Effect of Axial Loads on Natural Frequencies of Timoshenko Beam (축하중이 티모센코 보의 고유진동수에 미치는 영향)

  • Koo, Kyo-Nam
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • 제21권6호
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    • pp.580-586
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    • 2011
  • This paper addresses the effect of transverse shear deformation and rotary inertia on the natural frequency of beams under axial loads. It has been reported in the author's paper using a finite element analysis that the Timoshenko effect in a rotating disk deceases and then increases again with increasing rotation speed. To validate the phenomenon, the simply-supported beams under uniform tension are selected in this study since they have exact solutions in vibration problem. The results show that the axial tension in beams would not make the Timoshenko effect decrease monotonically but could make the effect increase again unlike the results reported in the other studies for beams.

A Study of Green and Its Imagery in Western Costume

  • Park, Mi-Yeon;Cho, Kyu-Hwa
    • Journal of Fashion Business
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    • 제7권6호
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    • pp.67-75
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    • 2003
  • In fashion history, the color "green" has been used from ancient to modern times constantly. Especially nowadays, the worth of green in fashion is becoming bigger than ever before to express the longing for pure nature. The purpose of this study is to define green's imageries in western costume history. For the basic about green, first of all, this study researched green of origin, effect and costumes in western history, then classified green's imageries. Green's imageries expressed in western costumes can be divided mainly into a 'nature imagery' and a 'religious divinity imagery'. Nature imagery was extended again into 'youth, devil, citizen and ecology image'. Youth image came from the luxurious feature of nature and it was extended again into 'innocent love, virgin and immaturity'. Religious divinity imagery has been represented in the ancient Egypt, Islam and Christian religion. In those cultures, green was considered as a sacred color of Osiris, Mahomet and Holy spirit.

Tasi vs. Tto (‘다시’와 ‘또’)

  • Yoon, Jae-Hak
    • Language and Information
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    • 제11권2호
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    • pp.1-22
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    • 2007
  • This paper examines tasi and tto, two Korean adverbs with roughly the same semantic value of again. It presents two empirical generalizations: (i) semantically tasi can mark the recovery of the original state, modifying an eventuality that is token-identical to a contextually-given eventuality, whereas tto is only limited to mark a simple repetition, thus modifying a type-identical event; (ii) functionally tasi can modify result states, but tto cannot. Then, it illustrates how the functional difference of result state modification can be accounted for by the notion of default events.

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Synthesis of Copoly(amide-imide)s Based on Silica Nano Particles-polyacrylamide

  • Min, Jun Ho;Park, Chan Young;Min, Seong Kee
    • Elastomers and Composites
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    • 제51권2호
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    • pp.138-146
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    • 2016
  • It is an inconvenience for silica nano-particles to dry again when using it in that they cohere each other through moisture in the air. Acrylamide groups were introduced to improve such inconvenience and copolymerized with silica nano-particles and then we copolymerized again with polyamic acid in order to increase thermal characteristic. Amide block copolymers were prepared using silica and (3-mercaptopropyl) trimethoxysilane (MPTMS) with a siloxane group, using 2,6-Lutidine as a catalyst. Amide block polymers and copolymers were synthesized via ATRP after brominating pyromellitic dianhydride (PMDA) and polyamic acid of methylene diphenyl diamine (MDA), using ${\alpha}$-bromo isobutyryl bromide. Characteristic peaks of copolymer with amide and imide groups and patterns of amorphous polymers were researched by FT-IR and XRD analyses and the analysis of surface characteristic groups was conducted via XPS. A change in thermal properties was examined through DSC and TGA and solubility for solvents was also researched.

Parametric Study on Rail and Bridge Interaction (레일과 교량의 상호작용 매개변수 분석 연구)

  • Kim, Jong-Min;Han, Sang-Yun;Lim, Nam-Hyoung;Kim, Jung-Hun;Kang, Young-Jong
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 한국전산구조공학회 2007년도 정기 학술대회 논문집
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    • pp.445-450
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    • 2007
  • CWR(Continuous Welded Rail) and bridge interaction produce rail force, bridge displacement and rail/bridge relative displacement. Each of these has limitation by many codes. In this paper, analysis of interaction has been carried out by using foreign codes(UIC 774-3 R code of Europe etc.) because there is no code about interaction between rail and bridge in Korea. Recently, railway bridges with CWR has been constructed for structural and economical reasons. When designer plans railway bridges, design a bridge model first and then investigate railway forces and displacement by interaction analysis. If these results go out bounds from limitation, designer plans railway bridges again and again. In this paper, using the parametric study on CWR and railway bridge interaction, railway bridge parameters such as length of bridge span, area of bridge, moment of inertia, stiffness of pier, etc. are presented. It helps preliminary design of railway bridges.

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Small-Scale Distribution Automation System Training Simulator Development (소규모 배전자동화 시스템 교육훈련용 시뮬레이터 개발)

  • Kim, Jae-Sung;Lee, Tae-Hyung;Kang, Suk-Kyun;Song, Wan-Seok
    • Proceedings of the KIEE Conference
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    • 대한전기학회 2000년도 하계학술대회 논문집 D
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    • pp.2889-2891
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    • 2000
  • We developed the training simulator for KEPCO operators to maintain small-scale distribution automation system effectively. The training simulator has the same screen form and operating environments in comparison with using system in field. It is to be wished that the operating techniques of KEPCO operators will progress to solve the fear of system operation and to training simulations of distribution conditions again and again.

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Behavior Analysis of Elevator Door (엘리베이터 도어의 거동해석)

  • Lee, Jong-Sun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • 제8권5호
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    • pp.991-994
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    • 2007
  • Recently, there has been major issue in safety of elevator. In the view of safe management of elevator, the corresponding research must be done since accidents related elevator include not only actual accident but also possible accident in order to protect user from dangerousness. This research aims to seek an analytical solution for safety apparatus which caused accident again and again among dangerous factors of an elevator. In order to assure safety of door, ANSYS, a commercial software was applied and evaluate safety qualitatively by calculating stress and strain deformed under the loads of 40 to 100kg.

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A Method of Using Discourse Analysis Activity in Task-based Korean Speaking Class (과제 수행 중심의 한국어 말하기 수업에서 담화 분석 활동의 활용 방안)

  • Kim, Jiyoung
    • Journal of Korean language education
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    • 제25권1호
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    • pp.29-52
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    • 2014
  • The purpose of this paper is to suggest a discourse analysis activity that can be used in the stage after performing tasks in task-based Korean speaking class and show its pedagogical advantages. A discourse analysis activity is an metadiscourse activity in which learners speak what they have spoken. By analyzing discourse and performing tasks again, learners can enhance their fluency and accuracy, make their knowledges in target language more stable and extend them, and develop problem solving skills. Consequently, this facilitates learners' acquisition of Korean language. This paper reviewed theoretical background of proposing discourse analysis activity, suggested the pedagogical advantages of the analysis, and examined discourse analysis activity in Korean speaking class. And it included the discourse sample of learners in actual class.

A Basic Study on Sugar Beet Culture in Reclaimed Salty Area 1. On the Sugar Accumulation of Sugar Beet in Reclaimed Salty Area (간척지에 있어서의 사탕무우 재배에 관한 기초적 연구 1. 간척지에서 사탕무우의 당축적에 관하여)

  • 임형빈
    • Journal of Plant Biology
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    • 제20권1호
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    • pp.23-27
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    • 1977
  • In order to investigate the possibility of sugar beet culture in reclaimed area of our country and the salt tolerance of sugar beet, a variety Kawemegapoly was used for experimentation in plots of various salt concentration arranged in Kimpo reclaimed area located at Kyongkido Province. The salt concentration of cultivating layer of the field in the west coast of Korea began to decline from the middle of June and rises again in the middle of October growing season of sugar beet as generally seen in relaimed paddy fields of Korea. The soil of less than 0.5% salt concentration is most suitable for the culture of sugar beet has bery strong salt tolerance. The sugar accumulation of sugar beet in each plot declined once in the middle part or in latter September and began to proceed again from the early of October. Such temporary retrocession of sugar accumulation was observed.

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