• Title/Summary/Keyword: Lee Sam

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A Study on the Establishing System of Truck Collaboration for Transportation Enterprises (화물자동차의 공동수배송시스템 구축에 관한 연구)

  • Lee, Sam-Jae;Kang, Kyung-Sik
    • Journal of the Korea Safety Management & Science
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    • v.9 no.6
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    • pp.137-146
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    • 2007
  • The objective of this paper is to study the establishing system of truck collaboration and to reduce traffic cost for participating transportation enterprises. The system of truck collaboration can enhance the transport efficiency and to reduce traffic cost without new investment for trucks and equipments. The type of truck collaboration should be enumerated (1) the system of head and branch base (2) the system of central terminal (3) the system of separating collection and delivery for cargo (4) the system of cooperating cargo order and truck allocation. The efficiency of truck collaboration is possible to be realized for transportation enterprises, receiver and sender of cargo.

A study on Noise Generation and Awareness of the Fire Alarm Sound in the Factory (공장소음으로 인한 화재 경보음 인지 영향정도에 관한 연구)

  • Lee, Young-Sam
    • Journal of the Korea Safety Management & Science
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    • v.17 no.4
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    • pp.97-103
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    • 2015
  • The people who are in the noise factory are difficult to hear and recognize about fire and to evacuate quickly when a fire occurs. This study was conducted to analyze workplace's background noise of 31 factories in Incheon and to know the workplace noise level comparing to fire alarm sound level. The measured average noise level was 96.8dB(A). Noise level of measured result was exceeded as 6.8dB(A) comparing to NFSC (National Fire Safety Code) noise level of 90dB. NFPA suggests that when background noise exceeds 85dB or more than that, other methods should be considered to know alarm sound. Also fire alarm sound should exceed more than 15dB(A) comparing to background noise level. Therefore it was concluded that the design of the fire alarm systems should not be applied to the workplace without considering background noise and it needs to be improved with regulations and the systems.

A study on awareness rate of the fire alarm sound using Background noise in the factory (사업장의 소음분석을 통한 화재경보음 인지정도에 관한 연구)

  • Lee, Young-Sam;Rie, Dong-Ho
    • Proceedings of the Safety Management and Science Conference
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    • 2013.04a
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    • pp.409-420
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    • 2013
  • 본 연구에서는 인천광역시의 37개 사업장(공장)을 대상으로 작업현장의 소음을 측정 및 분석하여 소음이 화재경보음 인지에 미치는 영향을 분석하였다. 측정결과 평균소음이 95.8dB(A)나왔다. 이는 국내 경보장치 음량기준(화재경보음 발생장치에서 1m떨어진 곳에서 90dB이상)보다 5.8dB(A)높게 나왔다. 미국방화협회(NFPA)에 따르면 암소음(기기음)이 85dB(A)이거나 이상일 경우 화재경보음 인지정도가 미흡하기 때문에 다른 방법을 강구하도록 되어 있다. 또한 화재경보음은 암소음보다 15dB(A) 높아야 한다고 하고 있다. 따라서 주변의 환경을 무시한 획일적인 화재경보음 설계에 대해서 제도적 및 법적 개선이 필요하다고 사료된다.

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A simulation study on predicting the current collection performance in 400km/h on establishing the maximum speed test plan of the next Korean high speed train development project (차세대 고속철도의 최고속도 시험 계획 수립을 위한 집전 성능 예측 시뮬레이션)

  • Kwon, Sam-Young;Park, Chun-Soo;Cho, Yong-Hyeon;Lee, Ki-Won;Park, Young
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.428-432
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    • 2008
  • The next Korean high speed train development project is started. In testing stage of this project, the 400km/h maximum speed test will be conducted. In Korean railway infrastructure conditions the 400km/h seems to be a critical speed especially in the aspect of the overhead contact lines. The current collection performance of the 400km/h which is predicted by dynamic interaction simulation are described in this paper. To discuss the permissible criteria of contact forces, displacements and percentage contact loss, the French 575km/h current collection conditions are simulated. Furthermore, review of the simulation results of the Korean 400km/h current collection conditions is conducted through comparison with that of the French 575km/h.

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Synthetic $\beta$-Lactam Antibiotics IV. Antibacterial activity of some 7 $\beta$-[2-(2-Aminothizol-4-yl)-2-(methoxyimino) acetaido]-3-(1-alkyl-1H-terazol-5-yl)thiomethyl-cephalospoins

  • Lee, Duck-Hyung;Kim, Sam-Min;Park, Sang-Woo;Kim, You-Seung
    • Archives of Pharmacal Research
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    • v.13 no.4
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    • pp.385-387
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    • 1990
  • 3-[(1-Methyl-1H-tetrazol-5-y)thiomethyl] is one of the most important side chains in cephaloporins. This side chain which occures in numerous antibacterial agents, suc as cefamandole, latamoxef, cefoperazone, and cefmenoxime, contributes remarkable potency and broad spectrum. For the continuous work of study on the development of broad spectrum cephalosporins, we become interested in the effect of structural modification of the substituent at the N-1 position of mercaptoterazole toward biological activity because our recent work had demonstraated that the arylsubstituted mercaptotetrazoles (Fig. 1) had favorable effect on the activity against gram-positive bacteria. The main focus of this report was to investigate the relationship between activity and functional groups in the mercaptotetrazole.

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The Modeling of Power conversion system with PEM fuel cell (연료전지를 이용한 전력변환장치 시스템 모델링)

  • Han, Kyung-He;Kwon, Sam-Yung;Park, Hyun-June;Lee, Byung-Song;Baek, Soo-Hyun
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.1984-1989
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    • 2008
  • A powered system with fuel cell is regarded as a high current and low voltage source. Effects of the loads on the electrical power source are important to optimize the integrated power system. The design parameters of the system should be chosen by taking into account the characteristics of the fuel cell, so the costs of the power system at given operating conditions can be reduced. Furthermore, the dynamics characteristic of the system is crucial to acquire performance in applications, particularly interactions between loads and the fuel cell system. Currently, no integrated simulation has been approached to analyze interrelated effects. Therefore, the dynamic models of power conversion system with a PEM fuel cell that includes the PEM fuel cell stack, DC/DC converter and associated controls is developed. Electric lads for the system are derived by using a power theory that separates a load current into active, reactive, distortion or a mixed current component. Dependency of the DC capacitor on the loads are analyzed.

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Characteristic Analysis of a rotary small-scale model of a linear induction motor used for an urban railway transit (철도차량용 LIM의 회전형 축소모델의 특성 해석)

  • Yang, Won-Jin;Park, Chan-Bae;Lee, Hyung-Woo;Kwon, Sam-Young;Park, Hyun-June;Won, Chung-Yeun
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.2011-2014
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    • 2008
  • A linear induction motor for urban railway transit is accompanied with the end-effect and large air-gap comparing with a rotary induction motor. These cause amount of difference between simulation results and experiments. In order to figure out the difference, experiments based on a real-scale test bed are indispensable, however building a test-line and a test vehicle is so difficult that authors are going to make a small-scale model and simulate it for comparison. In this paper, A rotary-type small-scale model of a linear induction motor is designed. Thrust and normal force of the model have been analyzed with the variation of frequency and speed by using a Finite Element Method(FEM).

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A Shape Finding and Cutting Pattern Determination for Membrane Structures (막 구조물에 관한 형상 탐색과 재단도 결정법)

  • Choi, Ho;Lee, Jang-Bog;Kim, Jae-Yeol;Sur, Sam-Uel;Kwon, Taek-Jin
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.04a
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    • pp.175-182
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    • 1998
  • The object of this study is shape finding and cutting pattern generation of membrane structures under the following assumptions : (1) material is linearly elastic (2) stress state is plane stress. Cable and membrane structures should introduce the nonlinear analysis considering geometric nonlinearity because these structures deform largely under the external loads. The analysis procedure is consisted of three steps considering geometric nonlinearity unlike any other structures. First step is the shape finding analysis to determine the initial equilibrium shape. Second step is the stress-deformation analysis to investigate the behaviors of structures under various external loads. Once a satisfactory shape has been found, a cutting pattern based on the shape finding analysis may be generated from the view point of construction. In this paper, (1) shape finding analysis formulation and an example, (2) cutting pattern determination procedure using weighted least-square minimization flattening method and some results are presented.

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A Study on the Cutting Pattern Determination for Fabric Structures (막 구조물의 재단 패턴 결정에 관한 연구)

  • Choi, Ho;Lee, Jang-Bog;Kim, Jae-Yeol;Sur, Sam-Uel;Kwon, Taek-Jin
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.10a
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    • pp.266-273
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    • 1998
  • The object of this study is shape finding and cutting pattern generation of membrane structures under the following assumptions: (1) material is linearly elastic (2) stress state is plane stress. Cable and membrane structures should introduce the nonlinear analysis considering geometric nonlinearity because these structures deform largely under the external loads. The analysis procedure is consisted of three steps considering geometric nonlinearity unlike any other structures. First step is the shape finding analysis to determine the initial equilibrium shape. Second step is the stress-deformation analysis to investigate the behaviors of structures under various external loads. Once a satisfactory shape has been found, a cutting pattern based on the shape finding analysis may be generated from the view point of construction. In this paper, after shape finding analysis, cutting pattern determination procedure using weighted least-square minimization flattening method and some results are presented.

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