• Title/Summary/Keyword: Choi criteria

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Floor Vibration Analysis of Economic Steel (ES) Beam Using Field Measured Acceleration Responses (진동특성을 고려한 ES-빔 공법의 사용성능 평가)

  • Woo, Jong-Yeol;Park, Soo-Yong;Kim, Min-Jin;Hong, Seong-Wook;Doh, Sun-Boong;Choi, Tae-Ho
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.11a
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    • pp.83-84
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    • 2011
  • This study provides floor vibration analysis for a factory constructed by ES-beam using field measured acceleration data. The natural frequencies of the first two modes of floor are extracted from measured data. With this information, a system identification has been performed to produce a numerical model representing existing floor. The peak magnitudes of acceleration for one man walking heel drop load from experiment and numerical model are analyzed using ISO vibration criteria and AIJ vibration performance criteria. The results show that there is no problem in use of ES-beam.

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Characteristics of the Running behavior and Safety for Tilting train due to Vertical Alignment (틸팅열차의 주행안전성과 고저틀림의 상관성 분석)

  • Choi, Il-Yoon;Um, Ju-Hwan;Lim, Yun-Sik
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.1937-1942
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    • 2010
  • Vehicle dynamic behavior should be investigated to establish the track irregularity criteria because they have an impact on vehicle dynamic behavior. The tilting train which have been developed in Korea will be operated on the conventional line. Therefore, it should be checked that the track irregularity criteria of conventional line is still available for the new vehicle. In this paper, the influence of vertical alignment on running behavior and safety for tilting train was instigated by numerical analysis. The wavelength and amplitude of vertical alignment were considered in scenario of this numerical analysis. This research is based on just numerical analysis and the final result which include measurement will be published in the future.

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A Study on New Village Planning in the Farming Zone of Saemangeum Reclaimed Area (새만금간척지 신농촌마을 계획수립연구)

  • Shim, Hwan-Hwi;Choi, Soo-Myung;Cho, Joong-Hyun
    • Journal of Korean Society of Rural Planning
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    • v.17 no.4
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    • pp.61-74
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    • 2011
  • Based on the critical review of previous new village planning proposals in Saemangeum Farming Zone, this study tried to derive rational and realistic planning/design criteria for new villages firstly through home-and-abroad case studies analysis, interview works on farmers in two villages located in the existing reclaimed farming areas and influential zone analysis from neighborhood villages in old land. By applying these criteria(population structure, farming size, maximum distance between farmland and home, village site size, number of new villages planned) on Saemangeum Farming Zone, basic new village planning framework was proposed finally.

Optimum Design Criteria for Maximum Torque Density & Minimum Torque Ripple of SynRM according to the Rated Wattage using Response Surface Methodology (반응표면법을 이용한 동기형 릴럭턴스 전동기의 고토크밀도 및 저토크리플을 위한 용량별 최적설계)

  • Choi, Yun-Chul;Mun, Sung-Ju;Lee, Jung-Ho
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.780-781
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    • 2008
  • This paper deals with optimum design criteria for maximum torque density & minimum torque ripple of Synchronous Reluctance Motor (SynRM) according to the rated wattage using response surface methodology (RSM). The RSM has been achieved to use the experimental design method in combination with Finite Element Method and well adapted to make analytical model for a complex problem considering a lot of interaction of design variables. The proposed procedure allows to define the rotor optimum shape for maximum torque density & minimum torque ripple starting from an existing motor or a preliminary design.

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On the Relationship Between the Performance Criteria of Unitary Space-Time Codes with Noncoherent and Coherent Decoding

  • Cheun, Kyung-Whoon;Kim, Jeong-Chang;Choi, Soong-Yoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.12A
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    • pp.1145-1151
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    • 2010
  • Hochwald et al. introduced unitary space-time codes for quasi-static Rayleigh fading channels which allows for noncoherent decoding when the channel response is not known at the receiver. However, when reliable information on the channel response is available, coherent decoding is preferable for improved performance. Here, we study the relationship between the performance criteria on the diversity and coding advantages provided by unitary space-time codes with noncoherent and coherent decoding. We show that when a unitary space-time code achieves full spatial diversity with noncoherent decoding, full spatial diversity is also guaranteed with coherent decoding.

Effect of Maunfacturing Methods on Content Uniformity of Tablets (제제방법(製劑方法)이 정제(錠劑)의 함량균일성(含量均一性)에 미치는 영향(影響))

  • Lee, Min-Hwa;Choi, Hoo-Kyun;Kim, Kil-Soo
    • Journal of Pharmaceutical Investigation
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    • v.11 no.1
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    • pp.6-14
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    • 1981
  • Safety, efficacy and reliability are the three basic criteria that define the quality of any well-designed pharmaceutical dosage form. Content uniformity directly bears on each of the three criteria defining the quality of drug product. Effect of manufacturing methods and physicochemical properties of the drug on content uniformity of tablets was investigated. Chlorpheniramine maleate and micronized salicylic acid were used as main ingredients. Three different methods for incorporation of main ingredients with diluents were solvent mixing method, geometric dilution method, and simple mixing method. The solvent mixing method was the best one of the three.

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Phonological Analysis of Phonological Disorders and Normal Children by Whole-Word Approach (단어 단위 접근법을 이용한 음운장애 아동과 정상 아동의 음운 분석)

  • Kim, Young-Eun;Choi, Sung-Il;Park, Sang-Hee
    • Speech Sciences
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    • v.13 no.4
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    • pp.143-155
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    • 2006
  • Recently, many researchers have been interested in children with phonological disorders. The purpose of this study was to examine those children in comparison with normal children and to find better assessment criteria of the whole-word approach. Three children with phonological disorders and three normal children of 5 to 7 years old participated in the picture description tasks. Results of this study were as follows: there was a significant difference in the whole-word assessment between normal and phonological disorder children. Such criteria as whole-word correctness, whole-word complexity, whole-word intelligibility proved to be good for diagnosing children's phonological disorders. Further studies would be desirable to apply the approach to more children of various age groups.

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Design of Substation Grounding Grid for Reduction of Touch Voltage (접촉전압 저감을 위한 변전소 접지망 설계)

  • Choi, J.K.;Kee, H.C.;Jung, G.J.;Kim, B.J.
    • Proceedings of the KIEE Conference
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    • 1999.07e
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    • pp.2352-2354
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    • 1999
  • The purpose of substation grounding system is to provide reference potential with power system and protect field workers from electrical shock resulted from unsymetrical power system faults. For this purpose, grounding grid should be designed to maintain max, touch voltage under safety criteria in fault conditions. It is difficult, however, to design a safe grounding grid at very resistive or narrow area. This paper describes an example of substation grounding grid design procedures in such areas with very severe design conditions. By using grounding conductors, which is located close to earth surface, earth surface potential could be controlled effectively, so that maximum touch voltages is to be maintained under safety criteria.

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A Study on the Development of Performance Audit Model Using the System Dynamics (시스템다이내믹스 기법을 이용한 공공정책 성과감사 모형개발에 관한 연구)

  • Choi, Nam-Hee
    • Korean System Dynamics Review
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    • v.12 no.3
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    • pp.25-46
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    • 2011
  • Recently, performance auditing system of governmen is carried out as most promising framework of government audit. Performance audit by the Board of Audit and Inspection of Korea involves assessing the causes and effects of government policies, programs, and Institutions with the criteria of economy, efficiency, effectiveness. Performance auditing will contribute to strengthening the values of objective assessments of whether public resources are responsibly and effectively managed to achieve intended results. Nevertheless, there seems to be a problems appears in implementation of audit. That is the problems of tendency return to legitimacy audit which is result from the lack of strong approach and methodology. So, this study purpose to developing stronger audit concepts and methods that add to the process and framework of traditional performance auditing system. First, this study evaluates the limitation of current performance auditing system with the perspective of systems thinking. Second, this study analyzes the process and method of current system and develop the conceptual model of the Dynamics Audit System using the system dynamics methodology, which focused on the appropriate auditing process and framework.

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A Study on the Water Resource and Environmental Pollution Level of Education Facilities in Green Building Certification Criteria (학교시설 친환경건축인증 사례를 통한 수자원 및 환경오염 평가항목 연구)

  • Kwag, Moon-Geun;Choi, Chang-Ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.12
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    • pp.678-687
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    • 2009
  • The purpose of this study is to develop the assessment category, items, a detail standard for environmentally friendly evaluation on the school. and to analyze the plan to improve the level of certification criteria on the School's water resource and environmental pollution. The results of this study brings on promoted environmentally friendly appreciation, resource con servation, reduction of contaminant, accordance in and around building, etc. For this purpose, analysis of domestic and foreign environmental friendly architectural citation screening system-BREEAM (1991), LEED 2.0(2001) etc.-was preceded, and through interview, survey and forum with professional group, developed evaluation item was verified and reappraised. Developed evaluation item were composed of 40 schools about water resource and environmental pollution.