• 제목/요약/키워드: Choi criteria

검색결과 2,154건 처리시간 0.032초

석유화학 플랜트의 배관계 설계기준에 대한 연구 (A Study on Design Criteria of Piping System in Petrochemical Plant)

  • 민선규;최명진
    • 한국정밀공학회지
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    • 제19권6호
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    • pp.192-199
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    • 2002
  • Largely, there are three kinds of the design criteria of piping system in petrochemical plant. The first is on the pipe thickness in accordance with the design pressure of piping system. The second is on the static state evaluation by thermal growth and the other is on the dynamic evaluation by piping vibration. According to the ASME B31.3 code, the internal pressure design thickness fur straight pipe shall be calculated as a code formula. And the static design by thermal displacement is defined 7000 cycles of fatigue life in operating the piping system with a design condition. However, the dynamic design evaluation in comparative with small displacements of high frequencies to the static condition has not established clearly the method, yet. So, this study purposes to present the trial of a proposal of dynamic design criterion on the basis of static design method.

침 금속재료에 대한 생체적합성 연구 - 생물학적 특성을 중심으로(2) - (A Study of Biocompatibility of Acupuncture's Metal Materials - Focused on Biological Character (2) -)

  • 정인태;강중원;백용현;이상훈;이재동;최도영
    • 대한한의학회지
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    • 제26권2호
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    • pp.166-175
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    • 2005
  • Objecitve: To present criteria for acupuncture standardization, which will improve the quality of acupuncture and secure safety, through studies of the biocompatibility of acupuncture needles. Methods: Acupuncture needles distributed in Korea were studied. Acute poisonous tests and pyrogenicity materials tests were executed to study the biocompatibility of acupuncture needles. Results & Conclusions: All 3 brands of acupuncture needles commonly distributed in Korea were found suitable for medical use, through acute poisonous tests and pyrogenicity materials tests. However, the medical instrument standards of the Korea Food and Drug Administration for acupuncture lack criteria concerning acute poisonous tests and pyrogenicity materials tests. The criteria for these tests should be standardized in order to secure the biocompatibility of acupuncture needles.

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다양한 형태의 데이터 입력을 지원하는 AHP 시스템 개발 및 전략적 의사 결정에의 응용 (Development of Various Input Supporting AHP System and Its Application to Strategic Decision Making)

  • 최상현;김진욱;한관희
    • 산업공학
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    • 제24권3호
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    • pp.210-219
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    • 2011
  • The traditional AHP(Analytic Hierarchy Process) is to evaluate subjectively the alternatives in the view point of each of criteria and has been widely used at the fields of real world application. The AHP has some drawbacks that makes it difficult to keep the consistency of decision makers' input and take too long to get accurate results because of requiring lots of pairwise comparison between criteria and alternatives. This research is to propose and develop a Hybrid-AHP system for complementing the critical points of traditional AHP methodologies. This system gets the quantitative information as well as qualitative inputs as the comparative ones between criteria and alternatives. We use the input as various type of information such as quantitative values, 9-scale ratings, and fuzzy-based inputs. Finally, we applied the system to the case of choosing strategic industries. The case study have shown the use of various input methods saves processing time, and reduces the input burden of users.

지하주차장 차량하중에 따른 구조체의 영향분석 (Structural Analysis of Underground Parking Garage Under Vehicle Load)

  • 김영진;이범식;최동섭;오효근;강창범
    • 복합신소재구조학회 논문집
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    • 제4권4호
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    • pp.22-29
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    • 2013
  • Accumulation of more than 20,000,000 vehicles since the establishment of the quality of life and economic development needs several parking lots and cause crack problem in Korea. Related structures in large cities due to the lack of parking garage attached to secure underground parking structures are actively being built, and the basement parking lot will continue to increase more stories and the trend is expected to be larger. But so far, construction of the underground parking structure is related to a number of problems, including cracks in the structure. Therefore, in this study, repair, reinforcement and a few non-economic losses in the current design criteria are presented. The review of the structure used to current design criteria is to minimize crack and maximize usability.

수치해석을 이용한 이중보온관 발파진동 관리기준에 관한 연구 (A Study on Blasting Vibration Control Criteria for Pre-insulated Pipe through the Numerical Analysis)

  • 최봉혁;조진우;김진만;유한규
    • 대한토목학회논문집
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    • 제33권4호
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    • pp.1471-1478
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    • 2013
  • 본 논문에서는 이중보온관의 발파진동 관리기준 제시를 위하여 이격거리와 매설심도를 변수로하여 수치해석을 수행하였다. 수치해석 적용 발파하중 모델은 현장시험 결과와의 비교를 통하여 검증하였다. 수치해석 결과, 이중보온관은 진동속도 4.0cm/sec 이상에서 발생 유효응력이 내관의 허용응력을 초과하거나 근접하는 것으로 나타났으며, 4.0cm/sec 이하에서 안정성이 확보되는 것으로 평가되었다. 따라서, 이중보온관의 진동관리기준은 4.0cm/sec를 초과하지 않도록 관리하여야 할 것으로 판단된다.

A Study on Voice Communication Quality Criteria Under Mobile-VoIP Environments

  • Choi, Jae-Hun;Seol, Soon-Uk;Chang, Joon-Hyuk
    • The Journal of the Acoustical Society of Korea
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    • 제28권2E호
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    • pp.35-42
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    • 2009
  • In this paper, we present criteria of objective measurement of speech quality to provide the mobile-VoIP services efficiently over wireless mobile internet. The mobile-VoIP service, which is based on mobility and is error-prone compared to conventional VoIP over wired network, is about to be launched, but there have not been adequate quality indexes and the Quality of Service (QoS) standards for evaluating speech quality of Mobile-VoIP. In addition, there are many factors influencing on the speech quality in packet network of which packet loss contribute directly to the overall voice communication quality. For this reason, we adopt the Gilbert-Elliot Channel Model for modeling packet network based on IP and assess the voice quality through the objective speech method of ITU-T P. 862 PESQ and ITU-T P. 862.1 MOS-LQO under various packet loss rates in the transmission channel environments. Our simulation results address the specific criteria and QoS for the mobile-VoIP services in terms of the various packet loss environments.

CC와 CEM의 평가요구사항 분석 (Analysis of Evaluation Requirement for CC and CEM)

  • 강연희;방영환;최성자;이강수
    • 디지털콘텐츠학회 논문지
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    • 제5권2호
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    • pp.95-100
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    • 2004
  • 정보보호 수준을 향상시키기 위해 정보보호시스템 평가$\cdot$인증에 대한 필요성이 높아지고 있으며 선진국에서는 정보화 역기능 위험 방지를 위해 제도적 일환으로 자국의 환경에 적합한 평가$\cdot$인증제도를 마련하여 정보보호시스템을 평가해 오고 있다. 그러나 상이한 평가기준의 적용으로 인한 시간 및 비용 소모의 문제점이 발생되었으며 이를 해결하기 위한 노력으로 현재 정보보호 시스템 평가를 위한 상호인증을 위해 공통평가기준(CC : Common Criteria)과 공통평가방법론(CEM : Common Evaluation Methodology)을 사용하고 있다. 선진화된 평가제도의 조기 정착과 효율적인 평가 준비 및 수행방법을 위한 정보보호시스템 평가 참여자들의 평가기준 및 방법론에 대한 유연하고 능동적인 해석이 필요하다.

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환경영향평가에서 있어서 신속영향평가(RIAM) 기법 적용방안 (Application of Rapid Impact Assessment Matrix for Environmental Impact Assessment)

  • 양원호;김임순;최원욱;한상욱
    • 환경영향평가
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    • 제11권3호
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    • pp.223-230
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    • 2002
  • The rapid impact assessment matrix (RIAM) might be a new tool for performance of an environmental impact assessment (EIA), comparing with many traditional methods of EIA, which have produced large reports setting out the subjective judgement reached by the assessors. The main criticisms of E1A are in part a natural result of the traditional method used. RIAM uses a structured matrix to allow for such judgement, both subjective and those based on quantitative data, to be made on a like-by-like basis, and provided a transparent and permanent record of the judgement made. Also, the computerized RIAM system using software program allows for the matrix to be shown in graphical form, which greatly enhances the clarity of the results produced by this method. RIAM provides a system by which development options and scenarios can be rapidly evaluated. To illustrate the use of RIAM, an example from an EIA study using application of scoping by assessment criteria in Environmental Impact Regulation of Korea was given. The criteria that might be used to evaluation EIA methods, and how RIAM measures up against these criteria, are discussed.

영아보육 프로그램의 질적 수준에 대한 보육시설의 자체평가 (Self-Evaluation of the Quality of Center-Based Infant/Toddler Care)

  • 최경애
    • 아동학회지
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    • 제25권5호
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    • pp.129-145
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    • 2004
  • This research aimed to analyze the quality of center-based infant/toddler programs in Korea. Scale for infant and toddler programs divide accreditation standards into 4 areas(physical environment, curriculum, health care, management system) with 60 standards. Standards can be divided into basic criteria and general criteria. The subjects are 149 day care centers(44 infant day care centers and 105 day care centers), and raters(teachers or principal) assessed the quality of each item on a 5-point Likert scale. The results of this study are as follows: 1) Self-evaluation result have marked 3.67 as average(range : 2.32~4.90), which barely meets basic criteria level. 2) Physical environment area has received worst score(3.41) and Health care area has received best score(3.92). 3) Each standard's score indicate the quality of infant/toddler care program: Feed care(4.29), Affectionate teacher-infant interaction(4.14) were highly rated while Nature environment/anmal/plant(2.75) and Teacher's facilities(2.74) were rated low. 4) Some variation factors showed differences in the qualitative level; number of child, education level of principal.

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천연가스 공급타당성 검토를 위한 영향요인 발굴 및 중요도 평가 (An Evaluation of the Weights and Investigation of the Impact Factors for Supplying LNG)

  • 홍성준;최봉하;이덕기;이정태;박수억
    • 한국수소및신에너지학회논문집
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    • 제20권1호
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    • pp.79-85
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    • 2009
  • In this paper, we investigated impact factors by brainstorming and survey research and calculated the weights of them using the Analytic Hierarchy Process(AHP) method in order to evaluate alternatives for supplying Liquefied Natural Gas(LNG). AHP is a useful method for evaluating multi-criteria decision making problems. We selected 3 criteria and 9 sub-criteria. According to the result in this study, the most important sub-criterion is the Government's Policy, and the second is the Province's Policy. The other side, the lowest important sub-criterion is the Investment Cost. This study may provide basic data to select the optimal alternative for supplying LNG.