• 제목/요약/키워드: , 1718)

검색결과 112건 처리시간 0.029초

직교이방성 무한평판 내부의 두 원공사이에 존재하는 균열의 해석 (Analysis of a Crack Approaching Two Circular Holes in an Orthotropic Infinite Plate)

  • 정성균;홍창선
    • 대한기계학회논문집
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    • 제17권7호
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    • pp.1710-1718
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    • 1993
  • This paper investigates the problem of a crack approaching two circular holes in an orthotropic infinite plate. The stress intensity factors were obtained by using the modified mapping-collocation method. The present results show excellent agreement with existing solutions for a crack approaching two circular holes in an isotropic infinite plate. In the numerical examples, various types of cross-ply laminated composites were considered. To investigate the effect of orthotropy and geometry(d/R and a/(d-R)) on crack tip singularity, stress intensity factors were considered as functions of the normalized crack length. It is expected that the modified mapping-collocation method can be applied to the analysis of various kinds of cracks existing around the stress-concentration region of composite laminate.

Improvement of Plastic Deformation in Hetrogeneous Atomic Cu-Zr Amorphous Alloy with Distributed Nanocrystals

  • 박준영
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.1718-1722
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    • 2008
  • This study explores the influence of volume fraction of nanocrystals of Cu-Zr amorphous alloys on shear band formation. As the number of crystals with very tiny size increases, the strain localization, i.e. shear band, decreases without large drop of flow stress. The DPRs also depict no sudden drop and relatively high values. The strain state during the deformation represents a few shear bands at low volume fraction while there are no distinguishable shear bands at high volume fraction of nanocrystals.

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Blumlein 회로로 구성한 단방향 구형파 펄스 발생기 (Directonal Square Pulse Generator construct for Blumlein lain)

  • 김정달;장기혁;주성철;정장근;이덕진;이용길
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 E
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    • pp.1779-1781
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    • 1998
  • We are going to design the Square Pulse Generator use of PCPS (Photo-Conductive Power Switch) for Blumlein lain. The circeuit is made of LC device and it is simulated by Schematics Evaluation Version 8.0 of MicroSim. After charged by DC voltage 15[kV]. When the switch is ON, Square pulse is generated after pause time 1.7857[${\mu}s$]. The square pulse is maximum peak voltage 13.987[kV], pulsed width 3.4017[${\mu}s$], rising time 0.7474[${\mu}s$], falling time 1.1718[${\mu}s$].

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뇌서지에 의한 전력통신선로의 전위상승 (A Rise in Electric Potential of Telecommunication Line for Electric Power System by Lightning Surges)

  • 이복희;장석훈
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 E
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    • pp.1718-1720
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    • 1997
  • This paper deals with n rise in electric potential of telecommunication line for electric power system by lightning surges. When $1.2/50{\mu}s$ and $8/20{\mu}s$ impulse voltage and current were applied on telecommunication cable, the voltage waveforms at the end terminal and equipment were measured. The telecommunication lines, which consist of 60 conductors and 3.5km in length, have some surge protectors such as preposition lightning arrester and TVSS. In each case, the rise in electric potential was measured for differential mode and common mode, respectively. Also, the rise in ground potential and the induced voltages were measured and analyzed. As a result, a significant rise in ground potential was observed for lightning surge. It can cause failure or malfunction of telecommunication systems.

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Synthesis and Spectroscopic Characterization of the New Sitting-atop Complexes from Reaction of Zirconyl Nitrate and Free Base meso-Tetraarylporphyrins in Mild Conditions

  • Dehghani, Hossein;Mansournia, Mohammad Reza
    • Bulletin of the Korean Chemical Society
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    • 제30권8호
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    • pp.1715-1718
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    • 2009
  • A series of sitting-atop (SAT) complexes, [(ZrO)$H_2t(X)pp(NO_3)_2$], have been prepared via the reactions of free base meso-tetraarylporphyrins, $H_2$t(X)pp, with zirconyl nitrate hydrate, ZrO(N$O_3)_2{\cdot}xH_2$O. The products have been characterized by a variety of methods including $^1H\;NMR,\;^{13}C$ NMR, IR and UV-Vis spectroscopies, elemental analysis and conductance measurements. The data indicate that the meso-tetraarylporphyrins coordinate with two pyrrolenine nitrogen atoms to the zirconyl cation located above the distorted porphyrin plane and two protons remain on the pyrrole nitrogens. Such half sandwich-type sitting-atop complexes may be considered as models for the initial steps of the metallation of the macrocycles.

소비자 구매의사 정보 재사용과 전자상거래 시스템의 효율적 관리를 위한 에이전트 개발 (A Development of Agent for he Consumer Descision Information Reuse and Efficient Management of EC System)

  • 서순모;양해술;김정호
    • 한국정보처리학회논문지
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    • 제7권5S호
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    • pp.1708-1718
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    • 2000
  • In the operating of electronic commerce system, the information about consumer purchasing intention to product through e-mail has caused the problems in the management aspects. These are the using of information again and response to the situations promptly in consumer purchasing intension, etc. Moreover, it has brought out the issues timely to operate the electronic commerce system strategically with reapplication of consumer intention information. In this studies, the agent system AWEC(Agent Windows for EC) was proposed as an alternative paln, which charges of he getting and transmitting information of consumers intension in the electronic commerce system. In this proposed AWEC, the functional structure and working allocation were executed. And also eh performance of the proposed system is analyzed and evaluated through experiment.

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Xe 분압비에 따른 AC PDP의 방전특성 연구 (A study of discharge characteristics by Xe content rates of AC PDP)

  • 이돈규;서동현;김동현;이호준;박정후
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 하계학술대회 논문집 C
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    • pp.1716-1718
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    • 2003
  • In order to realize the PDP that is better than CRT TV, high luminance and high efficient PDP panel should be fabricated. In order to meet these conditions it is inevitable trend to use high Xe% gas working gas. In this paper, we studied the relationships between the static margin, the discharge delay and jitter of PDP and Xe% in Ne gas.

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Analysis of the Effects of SD Plasma on Aerodynamic Drag Reduction of a High-speed Train

  • Lee, Hyung-Woo;Kwon, Hyeok-Bin
    • Journal of Electrical Engineering and Technology
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    • 제9권5호
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    • pp.1712-1718
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    • 2014
  • Experimental analysis according to the plasma actuator design variables was performed in order to verify the effects of sliding discharge plasma on aerodynamic drag reduction of a high-speed train. For the study, sliding discharge plasma actuator and high-frequency, high-voltage power supply were developed and experimented to figure out the best design variables for highest ionic wind velocity which could reduce the drag force. And then, 5% reduced-scale model of a high-speed train was built for wind tunnel test to verify it. From the results, it was confirmed that sliding discharge plasma had contribution to reduce the drag force and it had the potential to be applied to real-scale trains.

슬라이딩 모드를 이용한 로봇 매니풀레이터의 간접적응 자기조정 퍼지제어 (Indirect Adaptive Self-Regulating Fuzzy Control of Robot Manipulators Using Sliding Mode)

  • 박원성;양해원;정기철;김도우
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 제38회 하계학술대회
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    • pp.1718-1719
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    • 2007
  • In this paper, a fuzzy sliding mode control that combines with a adaptive self-regulating technique is proposed for manipulators with uncertainties. Especially the system uncertainties is approximated using fuzzy rule adaptation technique. The proposed controller is composed of the equivalent control that includes the approximation of the system uncertainties and the hitting control that is used to constrain the states of the system to maintain on the sliding surfaces and used to guarantee the system robustness. Simulation results are presented to show the effectiveness of the proposed controller

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Zn/Air Fuel Cell의 전기화학적 성능에 미치는 인자연구 (Factors Affecting on Electrochemical Performances for Zn/Air Fuel Cell)

  • 이창우;엄승욱;김현수;문성인;윤문수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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    • pp.1717-1718
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    • 2005
  • Zn/Air 전지는 방전하는 동안에 최종 방전 cut-off 전압에 이르기까지 평탄한 voltage profile의 전기화학적 특성을 보여준다. Air cathode 전극의 경우, 전극의 porosity에 따라 특성변화에 큰 영향을 가지는 것으로 보이며 이의 비교연구를 위해 사용되어지는 활성탄의 종류를 달리함으로써 이러한 인자의 영향을 이해하고자 하였다. 이러한 인자연구는 discharge voltage, specific capacity, 및 energy 등의 연구결과를 바탕으로 고찰되어졌으며 결과적으로 공기 유로를 통한 산소의 원활한 공급 여부가 주요 원인인 것으로 여겨진다.

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