• Title/Summary/Keyword: Best Value

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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

THE STUDY OF MULI-LEVEL PERFORMANCE MEASUREMENT APPROACH FOR VALUE MANAGEMENT OF CIVIL INFRASTRUCTURE PROJECTS

  • Jong-Kwon Lim;Min-Jae Lee;Dong-Youl Lee
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.1294-1299
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    • 2009

  • Best value in value engineering has relation to cost and performance. But a severe problem in VE study of a project is to reduce value due to loss of performance, caused by focusing on cost reduction. Also a lack of understanding performance concept, no trial VE workshop as well as cost saving-based policy have not satisfied customer needs. A efficient and practical methodology for accomplishing best value in construction projects is proposed. This study developed a more objective approach for performance measurement approach of mega projects and suggested a systematic process of performance quantitative analysis verifying value improvement. The proposed performance measurement method would be very useful for better communication and consensus between stakeholders and VE team especially through value engineering.

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Contractor Selection Method for Public Design-Build Projects (대형 공공 일괄입찰사업의 낙찰자 선정방식에 관한 연구)

  • Jung Dae-Won;Koo Kyo-Jin;Hyun Chang-Taek
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2006.05a
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    • pp.119-124
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    • 2006

  • Design-Build, one contractor is responsible for both the design and construction, has become more popular since the government framed the policy on how to activate the design-build projects in 1996. The reality is, however, there are many problems encounted on Contractor Selection Method for Public Design-Build Projects. The purpose of this paper is to improve the problems, no way to meet the goal(value) the owners expect from the design-build projects, for instance, not fully reflecting the characteristics of projects and owners intention, not systematical enough to judge if bidders could carry out the contract. This study will insist we introduce Best Value Procurement, which is being commonly used in some advanced countries recently, so that we would properly select the contractor suitable for Best Value concept which totally depends on the owners, types of work and specified conditions. Furthermore, by passing through the Two-Step Procedures following Pre-qualification in Best Value Procurement, we expect it lighten the bidders' burden for proposal and the owners' complicate bid administration.

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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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Evaluation of the effect of abutment preparation angles on the repeatability and reproducibility using a blue light model scanner

  • Kim, Dong-Yeon
    • The Journal of Advanced Prosthodontics
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    • v.12 no.4
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    • pp.210-217
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    • 2020

  • PURPOSE. The purpose of the study is to evaluate the repeatability and reproducibility of the abutment angle using a blue light scanner. MATERIALS AND METHODS. 0°, 6°, and 10° wax cast abutment dies were fabricated. Each of the silicone impression was produced using the replicable silicone. Each study die was constructed from the prepared replicable stone used for scans. 3-dimensional data was obtained after scanning the prepared study dies for the repeatability by using the blue light scanner. The prepared 3-dimensional data could have the best fit alignment using 3-dimensional software. For reproducibility, each abutment was used as the first reference study die, and then it was scanned five times per each. 3-dimensional software was used to perform the best fit alignment. The data obtained were analyzed using a nonparametric Kruskal-Wallis H test (α=.05), post hoc Mann-Whitney U test, and Bonferroni correction (α=.017). RESULTS. The repeatability of 0°, 6°, and 10° abutments was 3.9, 4.4 and 4.7 ㎛, respectively. Among them, the 0° abutment had the best value while the 10° abutment showed the worst value. There was a statistically significant difference (P<.05). The reproducibility of 0°, 6°, and 10° abutments was 6.1, 5.5, and 5.3 ㎛, respectively. While the 10° abutment showed the best value, the 0° abutment showed the worst value. However, there was no statistically significant difference (P>.05). CONCLUSION. In repeatability, the 0° abutment showed a positive result. In reproducibility, the 10° abutment achieved a positive result.

  • https://doi.org/10.4047/jap.2020.12.4.210 인용 PDF KSCI

Changes in Color and Textural Properties of Acorn Bread According to Added Amount of Soymilk (두유 첨가에 따른 도토리식빵의 색도 및 조직감 특성 변화)

  • Kim, Jeong-Mee;Yoon, Gye-Soon;Jo, Jung Im
    • Journal of the Korean Society of Food Culture
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    • v.31 no.6
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    • pp.605-615
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    • 2016

  • The objective of this study was to prepare acorn bread added with soymilk in order to improve its quality and develop the best possible recipe. The loaf volume, color, texture and sensory evaluation of acorn bread added with soymilk 10~40% were measured during the storage period. The L-value significantly decreased upon addition of 40% soymilk. A-value increased, but b-value decreased. During the storage period, the L- and a- values increased except 2 days at room temperature and 7 days in a freezer, whereas b-value decreased. For textural measurement, hardness, springiness, gumminess and brittleness increased significantly upon addition of soymilk. However cohesiveness decreased for 2 days of storage, whereas gumminess and brittleness for 1 day of storage at room temperature. Freezer storage for 1 day reduced cohesiveness, and gumminess for 4 and 7 days, respectively, and brittleness after all storage periods. The sensory evaluation showed that acorn bread added with soymilk 20% produced the best results in color and taste. The bitter aftertaste increased according to addition of soymilk with lower scores. Softness, chewiness and overall preference decreased significantly. Therefore, 10% soymilk addition got the best scores in aftertaste, softness, chewiness and overall acceptances.

  • https://doi.org/10.7318/KJFC/2016.31.6.605 인용 PDF KSCI

HS-PSO Hybrid Optimization Algorithm for HS Performance Improvement (HS 성능 향상을 위한 HS-PSO 하이브리드 최적화 알고리즘)

  • Tae-Bong Lee
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.16 no.4
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    • pp.203-209
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    • 2023

  • Harmony search(HS) does not use the evaluation of individual harmony when referring to HM when constructing a new harmony, but particle swarm optimization(PSO), on the contrary, uses the evaluation value of individual particles and the evaluation value of the population to find a solution. However, in this study, we tried to improve the performance of the algorithm by finding and identifying similarities between HS and PSO and applying the particle improvement process of PSO to HS. To apply the PSO algorithm, the local best of individual particles and the global best of the swam are required. In this study, the process of HS improving the worst harmony in harmony memory(HM) was viewed as a process very similar to that of PSO. Therefore, the worst harmony of HM was regarded as the local best of a particle, and the best harmony was regarded as the global best of swam. In this way, the performance of the HS was improved by introducing the particle improvement process of the PSO into the HS harmony improvement process. The results of this study were confirmed by comparing examples of optimization values for various functions. As a result, it was found that the suggested HS-PSO was much better than the existing HS in terms of accuracy and consistency.

  • https://doi.org/10.17661/jkiiect.2023.16.4.203 인용 PDF HTML

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$