• Title/Summary/Keyword: auxiliary method

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Auxiliary domain method for solving multi-objective dynamic reliability problems for nonlinear structures

  • Katafygiotis, Lambros;Moan, Torgeir;Cheungt, Sai Hung
    • Structural Engineering and Mechanics
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    • v.25 no.3
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    • pp.347-363
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    • 2007
  • A novel methodology, referred to as Auxiliary Domain Method (ADM), allowing for a very efficient solution of nonlinear reliability problems is presented. The target nonlinear failure domain is first populated by samples generated with the help of a Markov Chain. Based on these samples an auxiliary failure domain (AFD), corresponding to an auxiliary reliability problem, is introduced. The criteria for selecting the AFD are discussed. The emphasis in this paper is on the selection of the auxiliary linear failure domain in the case where the original nonlinear reliability problem involves multiple objectives rather than a single objective. Each reliability objective is assumed to correspond to a particular response quantity not exceeding a corresponding threshold. Once the AFD has been specified the method proceeds with a modified subset simulation procedure where the first step involves the direct simulation of samples in the AFD, rather than standard Monte Carlo simulation as required in standard subset simulation. While the method is applicable to general nonlinear reliability problems herein the focus is on the calculation of the probability of failure of nonlinear dynamical systems subjected to Gaussian random excitations. The method is demonstrated through such a numerical example involving two reliability objectives and a very large number of random variables. It is found that ADM is very efficient and offers drastic improvements over standard subset simulation, especially when one deals with low probability failure events.

Characteristics for Ground Impedance of Counterpoise according to Position of Auxiliary Probe and Frequency (보조전극의 배치 및 주파수에 따른 매설지선의 접지임피던스 특성)

  • Gil, Hyoung-Jun;Kim, Dong-Woo
    • Journal of the Korean Society of Safety
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    • v.27 no.4
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    • pp.33-37
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    • 2012
  • This paper describes the characteristics for ground impedance of counterpoise according to position of auxiliary probe and frequency using the fall-of-potential method and the testing techniques to minimize the measuring errors are proposed. The fall-of-potential method is theoretically based on the potential and current measuring principle and the measuring error is primarily caused by the position of auxiliary probes. In order to analyze the effects of ground impedance due to the distance of the current probe and frequency, ground impedances were measured in case that the distance of current probe was located from 10[m] to 100[m] and the measuring frequency was ranged in 55 [Hz], 128[Hz], 342[Hz], and 513[Hz]. The results could be help to determine the position of auxiliary probe when the ground impedance was measured at grounding system.

Precise Stereo Matching Technique Based on White Auxiliary Stripe (백색 보조 띠 기반의 정밀 스테레오 정합 기법)

  • Kang, Han-Sol;Ko, Yun-Ho
    • Journal of Korea Multimedia Society
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    • v.22 no.12
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    • pp.1356-1367
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    • 2019
  • This paper proposes a novel active stereo matching technique using white auxiliary stripe pattern. The conventional active stereo matching techniques that uses two cameras and an active source such as projector can accurately estimate disparity information even in the areas with low texture compared to the passive ones. However, it is difficult that the conventional active stereo matching techniques using color code patterns acquire these patterns robustly if the object is composed of various colors or is exposed to complex lighting condition. To overcome this problem, the proposed method uses an additional white auxiliary stripe pattern to get and localize the color code patterns robustly. This paper proposes a process based on adaptive thresholding and thinning to obtain the auxiliary pattern accurately. Experimental results show that the proposed method more precisely measures the stepped sample whose depth is known in advance than the conventional method.

A study on the arc suppressing method of switch gear using auxiliary contactor (보조접점에 의한 차단기의 arc억제에 관한 연구)

  • 노창주
    • Journal of Advanced Marine Engineering and Technology
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    • v.8 no.2
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    • pp.67-73
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    • 1984
  • The Author researched and published its results on how effectively the arcs suppressed when the contactors are opened at current zero point which indispensively exsists in AC circuits. In order to increase the effectiveness of suppressing the arcs in larger current, the author suggests a new suppressing method using auxiliary contactor which contains resistance which is connected in parallel with main contactor. The author's firm belief is that the arcs are suppressed remarkably, but there are several problems, especially how to determine the optimal resistance connected in series with auxiliary contactor.

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A Study on Establish the Foundation of Electronic Payment System for the Auxiliary Costs of Foreign Trade - Focused on Logistic and Customs Clearance Areas - (수출입 부대비용의 EPS 기반구축에 관한 연구 - 물류.통관부문을 중심으로 -)

  • Shim, Chong-Seok;Yang, Jung-Ho
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.47
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    • pp.185-212
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    • 2010
  • This study aims to derive practical suggestions to apply application methods by auxiliary costs, especially application of logistics and customs clearance areas in order to establish EPS support system of auxiliary cost occurred from export/import. For the propose, this study has analyzed types and situation of auxiliary costs, application method by auxiliary costs, payment situation of logistics auxiliary costs and clearance auxiliary costs and suggested the relevant problems and their application methods. Especially, in case of logistics auxiliary costs through connection to the attached general documents required for negotiation by reflecting characteristics of B2B transactions. In addition, it has suggested that those services by the said system should be conveniently used commonly by the export companies and logistics companies through provision of various payment measures, support of foreign currency payment, etc. and security of reliability/system stability, etc. for the compatible payment with other systems as the prerequisite for the successful settlement of the auxiliary costs EPS. It is expected that satisfaction of the uTradeHub users such as export/import companies and logistics companies will be increased, user-oriented customized information services such as raw cost prediction service through calculation of auxiliary costs could be available in the future and efficiency of work processes related to auxiliary costs will be increased, by providing the EPS through various single window based payment measures through establishment of the export/import auxiliary costs payment system.

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The Flicker Control by Feed-forward for Stabilization of CVCF Inverter (철도차량용 보조전원장치의 전향제어를 이용한 Flicker 제어)

  • 박채운;신형진;조국춘;원충연
    • Proceedings of the KSR Conference
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    • 1999.11a
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    • pp.267-272
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    • 1999
  • The auxiliary power supply system fur passenger service of railway car has been developed from MA(Motor-Alternator) to CVCF Inverter (Static Inverter). Generally, a customer wants to apply tile new control method and device for auxiliary power supply of railcar However, if the auxiliary power supply is supplied to extended existing line, the maintenance cost of the old system is less expensive than new developed system, so, the customer specifies that the auxiliary power supply has compatibility with existing one completely. At that time, the hardware is nearly same as existing system except small changes of accessories for better performance. This paper describes the flicker control using feed-forward method of auxiliary power supply system for new 50 electric railcars, which are delivered to Korean National Railroad (KNR) Kwa-chon Line. The existing power supply system has damping resistor box to stabilize the DC input (1.5 ㎸). At this time, for better system efficiency the new system has not include resistor box but new control method including feed-forward control is applied. This control algorithm realizes the better stabilization of input power compared to the result of the existing system, which includes resistor box

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Soft Switching boost converter for reduction of switch stress (스위치 스트레스 저감이 가능한 소프트 스위칭 부스트 컨버터)

  • Park, Seung-Won;Kim, Jun-Gu;Kim, Jae-Hyung;Eom, Ju-Kyoung;Won, Chung-Yuen;Jung, Yong-Chae
    • Proceedings of the KIPE Conference
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    • 2009.11a
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    • pp.155-157
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    • 2009
  • This paper proposed a soft switching boost converter with an auxiliary circuit, and a modified control method for reduction of switch stress. The proposed converter applies an auxiliary circuit, which is added to the conventional boost converter and used to achieve soft switching for both a main switch and an auxiliary switch. The auxiliary circuit consist of a resonant inductor and two capacitors, an auxiliary switch. The main switch is operated ZVS turn-on, turn-off also auxiliary switch is operated ZCS turn-on, ZVS turn-off. The proposed soft switching boost converter has lower switch loss and higher efficiency than conventional soft switching boost converter.

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Effectiveness of a Heat Transfer Characteristics of an Auxiliary Chamber for Performance of an Air Spring (보조용기의 열전달특성이 공기스프링의 성능에 미치는 영향)

  • Jang, Ji-Seong
    • Journal of Power System Engineering
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    • v.17 no.2
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    • pp.121-127
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    • 2013
  • The air spring is used widely because of the easy change of spring constant, and, a superior vibration and shock insulation performance. Among the apparatus using the merits of that, the air spring connected an auxiliary chamber has been developed and used as a component of suspension system for an automobile and a railroad car. The purpose of this study is to suggest a design method reflecting heat transfer effect for an air spring system connected auxiliary chamber. In order to do so, this study investigates change of reaction force along with variations in heat transfer coefficient, and, analyzes an effectiveness of a heat transfer characteristics of an auxiliary chamber for external force attenuation characteristics and impedance characteristics of an air spring connected an auxiliary chamber.

Stereoscopic Video Coding Using MPEG-4 Multiple Auxiliary Component (MPEG-4 MAC(Multiple Auxiliary Component) 기반 스테레오스코픽 비디오 부호화)

  • 조숙희;윤국진;안충현
    • Proceedings of the IEEK Conference
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    • 2003.11a
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    • pp.167-170
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    • 2003
  • We propose stereoscopic video coding method using the syntax of MAC(Multiple auxiliary component) that was added to the MPEC-4 visual version 2 in order to describe the transparency of the video object. We also define the novel MAC's semantics in MPEG-4 that should support the proposed coding method. The major difference between the existing coding method and the proposed coding method is the addition of the residual texture coding. The proposed coding method assigns disparity map and residual texture to 3 components of MAC: one component for disparity map and the rest 2 components fer the luminance and chrominance data of the residual texture, respectively. The performance of the proposed method is evaluated in terms of PSNR by computer simulations.

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A Study on Safety Design of Auxiliary tank in a high-pressure air compressor (고압공기압축기의 보조탱크 안전설계에 관한 연구)

  • 강동명;오진수;이장규;우창기
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • 1997.11a
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    • pp.31-36
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    • 1997
  • Strength test using strain rosette gage have been conducted to investigate safety of an auxiliary tank in a high-pressure air compressor. Thickness of auxiliary tanks in 6063-T5 aluminum at toy are 9mm and 17mm. The result of strength test make a comparison the design in strength of materials by nominal stress and the design in fracture mechanics with consideration of crack size. Summarizing the result: Comparing with the safe working pressure of the strength test and that of the design method in strength of materials by nominal stress with the experimental values, it makes difference 11% and 39% for 9mm and 17mm thickness of auxiliary tanks, respectively, and that of the design method by fracture mechanics, it makes difference 4% and 5% for them, respectively. It is confirmed that the design by fracture mechanics is more economical and safe design than the design in strength of materials by nominal stress.

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