• Title/Summary/Keyword: the best value system

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Experimental Research on Finding Best Slip Ratio for ABS Control of Aircraft Brake System (항공기용 제동장치의 ABS 제어를 위한 최적 슬립율 결정에 관한 시험적 연구)

  • Yi, Miseon;Song, Wonjong;Choi, Jong Yoon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.5
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    • pp.597-607
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    • 2017

  • The general control method for Anti-lock Brake System(ABS) is that the wheel slip ratio is observed and the braking force is controlled in real time in order to keep the wheel slip ratio under the value of the best slip ratio. When a wheel runs on the state of the best slip ratio, the ground friction of the wheel approaches the highest value. The value of best slip ratio, theoretically, is known as the value between 10 and 20 % and it is dependant on the ground condition such as dry, wet and ice. It is an important parameter for the braking performance and affects the braking stability and efficiency. In this thesis, an experimental method is suggested, which is a reliable way to decide the best slip ratio through dynamo tests simulating aircraft taxiing conditions. The obtained best slip ratio is proved its validity by results of aircraft taxiing tests.

  • https://doi.org/10.9766/KIMST.2017.20.5.597 인용 PDF KSCI

A Study on the Evaluation System for Bidders to According to the Best Value Bid System by Technology Proposal Method (기술제안방식의 최고가치낙찰제도 입찰자 평가체계에 관한 연구)

  • Yeo, Sang-Ku;Lee, Gun;Lee, Hyun-Chul;Go, Seong-Seok
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2009.04a
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    • pp.211-216
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    • 2009

  • Bidding systems in the domestic public construction work have been amended many times since the lowest-bidding system was implemented in 1951. However, this hasn't had much success. Competition in technical development among companies has declined as the contracts for buildings are given to company which submits the lowest price without considering traits of projects. In addition, as the construction market turns to the limitless competition system due to FTA(Free Trade Agreement), advanced techniques are needed to promote the national competitive power. Considering the needs of the times, Korean government announced that "Best Value Contract (Design-Bid-Build)" and "Bridging Contracts (Design-Build)" are included to 4 existing bidding systems in October 2007. Thus this study aims to suggest devised the evaluation criteria including major items for evaluating bidders, in order to establish and revitalize the best-value bid system successfully.

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TECHNICAL PROPOSAL BASED COST REDUCTION BIDDING SYSTEM FOR SUPPLYING AFFODABLE HOUSING

  • Seunghee Kang;Jeongseok Lee;Gunhee Cho;Jeongrak Sohn;Jongdae Bang
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.1433-1439
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    • 2009

  • Best value is the ultimate goal of the owner and can thus have diverse meanings according to the project characteristic, owner's purpose, user groups' payment capability, etc.. Recently, resettlement problems of the marginalized members in the urban regeneration area have been issued in Korea because they have no capability to purchase (or lease) redeveloped housing (or apartment). It means that a minimized production cost for reducing supply price of housing is a key factor in establishing the best value of the marginalized members. The lowest-price bidding system serves the purpose of ensuring a minimized production cost, but due to the low-cost investments, it creates various problems, such as sloppy construction, lowered quality, an increased LCC, and worsening profitability for builders. Thus, to help them resettle, it is necessary to supply affordable housing geared towards a certain appropriate quality and minimum construction costs. Towards this end, this study aimed to propose a cost reduction bidding system based on a technical proposal. The proposed technical-proposal-based cost reduction bidding system consists of the following components: work-unit-based, project-unit-based, and construction-period-reducing technical proposals. These components are evaluated to select the best bidder for a given project. The technical proposal based cost reduction bidding system proposed herein is expected to provide facilities with appropriate supply prices and appropriate quality levels, to bolster the technological competitiveness of builders.

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Automated Visual Inspection System of Double Gear using Inspection System (더블기어 자동 시각 검사 시스템 실계 및 구현)

  • Lee, Young Kyo;Kim, Young Po
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.7 no.4
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    • pp.81-88
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    • 2011

  • Mini Double Gears Frame is critical part of PDP and also produces couple hundred thousand every month. In the process of mass production, product inspection is very important process. Double Gear, one of the part of machine, was inspected by human eyes which caused mistakes and slow progress. To achieve the speed and accuracy the system was compensated by vision system which is inspecting automatically. The focus value is measured based on the fact that high contrast images have much high frequency edge information. High frequency term of the image is extracted using the high-pass filter and the sum of the high frequency term is used as the focus value. We used a Gaussian smoothing filter to reduce the noise and then measures the focus value using the modified Laplacian filter called a Sum modified Laplacian Focus values for the various lens positions are calculated and the position with the maximum focus value is decided as the focused position. The focus values calculated in various lens position showed the Gaussian distribution. We proposed a method to estimate the best focus position using the Gaussian curve fitting. Focus values of the uniform interval lens positions are calculated and the values are used to estimate the Gaussian distribution parameters to find the best focus position.

  • https://doi.org/10.17662/ksdim.2011.7.4.081 인용 PDF KSCI

A Study on the Bidder Evaluation System Using the Technology Proposal-Based Best Value System (기술제안입찰형 최고가치 낙찰제도 입찰자 평가체계에 관한 연구)

  • Yeo, Sang-Ku;Lee, Hyun-Chul;Go, Seong-Seok
    • Korean Journal of Construction Engineering and Management
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    • v.11 no.2
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    • pp.124-136
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    • 2010

  • International construction market has been depressed significantly after 2000. Exclusive techniques and advanced construction management methods are desperately in demand so as to ensure the competitiveness in unlimited competition. Although public construction delivery system has been revised several times starting with introduction of the lowest bidding system in 1951, there has been no remarkable achievement whenever new system was introduced. This study analyzed the successful stories of developed countries like Europe, USA and Japan to settle successful rating system down and vitalize the best value system in Korea, which was introduced in October 2007. We constructed the bidder evaluation system for domestic situation, and designed the evaluation tool which is useful in utilization. Since this study were analyzed on only same systems of developed countries and domestic similar cases, this study is limited to typical construction in Korea. The study of specialized rating system in the field related should be followed.

  • https://doi.org/10.6106/KJCEM.2010.11.2.124 인용 PDF KSCI

An Adaptive K-best Algorithm Based on Path Metric Comparison for MIMO Systems (MIMO System을 위한 Path Metric 비교 기반 적응형 K-best 알고리즘)

  • Kim, Bong-Seok;Choi, Kwon-Hue
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.11A
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    • pp.1197-1205
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    • 2007

  • An adaptive K-best detection scheme is proposed for MIMO systems. The proposed scheme changes the number of survivor paths, K based on the degree of the reliability of Zero-Forcing (ZF) estimates at each K-best step. The critical drawback of the fixed K-best detection is that the correct path's metric may be temporarily larger than K minimum paths metrics due to imperfect interference cancellation by the incorrect ZF estimates. Based on the observation that there are insignificant differences among path metrics (ML distances) when the ZF estimates are incorrect, we use the ratio of the minimum ML distance to the second minimum as a reliability indicator for the ZF estimates. So, we adaptively select the value of K according to the ML distance ratio. It is shown that the proposed scheme achieves the significant improvement over the conventional fixed K-best scheme. The proposed scheme effectively achieves the performance of large K-best system while maintaining the overall average computation complexity much smaller than that of large K system.

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GPS Surveying by A Point Positioning (일점측위에 의한 GPS측정)

  • Lee, Y.H.;Mun, D.Y.
    • Journal of Korean Port Research
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    • v.12 no.1
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    • pp.119-130
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    • 1998

  • As a satellite positioning system, GPS is designed to provide the information on three dimensional position, velocity, and time all over the world. The purpose of this paper is to obtain what day has the best accuracy and what time has the best accuracy of measuring of forteen-twenty mimutes for effective using of MAGELLAN G.P.S NAV DLX-10 system. The result of measurement maximum deviation value from November, 1997 to March, 1998 that latitude deviation is 3' .75 and longitude deviation is 2' .1 And the result of measurement maximum deviation value during fourteen minutes of April 29, 1998 that latitude deviation is 3' .75 and longitude deviation is 1' .9. The result of measurement maximum deviation value during twenty minutes of May 6, 1998 that latitude deviation is 4' .75 and longitude deviation is 2' .1 and that is provid 3' .25, 4' .1 to May 13, 1998. So, we expect efficient use of horizontal position for navigation.

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Design of Digital Controllers with Self-Validating Intelligent Sensors (Self-Validating 지능형 센서를 사용한 디지털 제어기의 설계)

  • 나승유;배희종
    • Proceedings of the IEEK Conference
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    • 2000.06e
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    • pp.51-54
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    • 2000

  • We are concerned with processing methods of the measurement values of sensors in the control system. When some faults happen to sensor components, the measurement value of sensors cause the malfunction of the plant. So it is necessary to detect and reduce the influence of faults to control with reliability for the overall system. The sensor status must be always good for best demonstration of the controller performance. A self-validating sensor detects the sensor state from the measurement value, reconstruct a soft sensor and can improve reliability of the sensor. If sensor faults, the sensor is detected and reconstructed with the best estimate from its correlation to other sensors and historical data. It is applied to the control of a flexible link system with the sensor fault problems in the light sensor module for position to show the applicability. In this paper, we propose a digital controller which reduces deflection of the moving set-point by reconstructing output of a sensor when the sensor fault is detected.

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A Study on the Optimized Architectural Space Planning by Searching Algorithm Method (탐색적 방법에 의한 건축공간 배치계획 최적화에 대한 고찰)

  • Lim, Myung-Gu;Kim, Su-Young
    • Journal of The Korean Digital Architecture Interior Association
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    • v.1 no.1
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    • pp.51-58
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    • 2001

  • The purpose of this study is to improve productivity of architectural space planning(A.S.P,) by computer system and to optimize ASP. A searching algorithm is the best way to slave optimized A.S.P. Because architectural design is too many various site situations and client's demands to specify the general solving methods. This method seek the best design case in all possibility and to be modeled as this; $\rightarrow$[$\rightarrow$$\rightarrow$