• 제목/요약/키워드: Analysis

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On the Relationship between $\varepsilon$-sensitivity Analysis and Sensitivity Analysis using an Optimal Basis

  • Park, Chan-Kyoo;Kim, Woo-Je;Park, Soondal
    • Management Science and Financial Engineering
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    • 제10권2호
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    • pp.103-118
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    • 2004
  • $\epsilon$-sensitivity analysis is a kind of methods for performing sensitivity analysis for linear programming. Its main advantage is that it can be directly applied for interior-point methods with a little computation. Although $\epsilon$-sensitivity analysis was proposed several years ago, there have been no studies on its relationship with other sensitivity analysis methods. In this paper, we discuss the relationship between $\epsilon$-sensitivity analysis and sensitivity analysis using an optimal basis. First. we present a property of $\epsilon$-sensitivity analysis, from which we derive a simplified formula for finding the characteristic region of $\epsilon$-sensitivity analysis. Next, using the simplified formula, we examine the relationship between $\epsilon$-sensitivity analysis and sensitivity analysis using optimal basis when an $\epsilon$-optimal solution is sufficiently close to an optimal extreme solution. We show that under primal nondegeneracy or dual non degeneracy of an optimal extreme solution, the characteristic region of $\epsilon$-sensitivity analysis converges to that of sensitivity analysis using an optimal basis. However, for the case of both primal and dual degeneracy, we present an example in which the characteristic region of $\epsilon$-sensitivity analysis is different from that of sensitivity analysis using an optimal basis.

Bi-directional fault analysis of evaporator inspection system

  • Kang, Dae-Ki;Kang, Jeong-Jin
    • International journal of advanced smart convergence
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    • 제1권1호
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    • pp.57-60
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    • 2012
  • In this paper, we have performed a safety analysis on an automotive evaporator inspection system. We performed the bi-directional analysis on the manufacturing line. Software Fault Tree Analysis (SFTA) as backward analysis and Software Failure Modes, Effects, & Criticality Analysis (SFMECA) as forward analysis are performed alternately to detect potential cause-to-effect relations. The analysis results indicate the possibility of searching and summarizing fault patterns for future reusability.

문헌정보학분야에서 메타분석 연구에 관한 고찰 (A Review of the Meta-Analysis in Library and Information Science)

  • 노정순
    • 한국문헌정보학회지
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    • 제42권1호
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    • pp.45-61
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    • 2008
  • 메타분석(Meta-Analysis)이란 분석에 대한 분석(analysis of analysis)이란 의미로, 특정 연구문제에 대해 독립적으로 수행된 선행연구들의 일치하지 않은 결과들을 통합하여 결론을 내리기 위해 개개 연구의 분석결과들을 수학적으로 합성하여 통계적으로 결론을 내리는 방법이다. 본 연구는 메타분석의 특성과 기본원리, 분석 절차, 대표적인 분석모델을 소개하고, 문헌정보학분야에서의 메타분석연구를 고찰하였다. 다른 학문에 비해 문헌정보학에서 메타분석연구는 매우 소량 수행되었고 국내 문헌정보학분야에서는 전무한 상태이다. 문헌정보학에서 메타분석을 수행하는데 문제점과 메타분석연구를 활성화하기 위해 연구자가 보고서 작성시 유의해야 할 내용을 논의하였다.

원자로용 수중탐상기의 구조해석 (Structural Analysis of RIROB(Reactor Inspection Robot))

  • 권영주;최석호;김재희
    • 한국CDE학회논문집
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    • 제8권1호
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    • pp.19-26
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    • 2003
  • This paper presents the structural analysis of RIROB(Reactor Inspection Robot). Actually, several analyses such as kinetodynamics analysis, fluid mechanics analysis and structural mechanics analysis etc. should be carried out in the design of RIROB. These analyses are executed through the use of com-puter aided engineering(CAE) systems. The kinetodynamics analysis is carried out using a simple fluid dynamic analysis model for the water flow over the sensor support surface instead of difficult fluid mechanics analysis. Simultaneously the structural mechanics analysis is carried out to obtain the mini-mum thickness of the RIROB housing. The minimum thickness of the RIROB housing is evaluated to be 1.0 ㎝ for the safe design of RIROB. The kinetodynamics analysis of RIROB is performed using ADAMS and the static structural mechanics analysis of RIROB is performed using NISA.

예방접종의 경제성 평가방법과 사례 (Economic Evaluation of Vaccinations - a Methodologic Review)

  • 천병철
    • Pediatric Infection and Vaccine
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    • 제15권1호
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    • pp.20-29
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    • 2008
  • The basis of the economic evaluation of vaccination is the balance between the use of the resources (input) and the improvements that result from the vaccination (output). Techniques used for economic evaluation of vaccination are cost analysis, cost-minimization analysis, cost-effectiveness analysis, cost-utility analysis and cost-benefit analysis. Cost analysis seeks to characterize the costs of a given vaccination program. Cost-effective analysis is to helps policy-makers decide on the best use of allocated resources, whether cost-benefit analysis is to helps policy-makers decide on the overall allocation of resources. Cost-utility analysis is a specific form of cost-effective analysis in which outcomes are reduced to a common denominator such as the quality-adjusted life year (QALY) or disability-adjusted life year (DALY). Many economic analyses have been conducted on vaccines in the world, but there have been a little studies on economic evaluation on vaccines in Korea. This paper reviewed the methodology used to economic evaluation on vaccines and immunizations and addressed some examples of the methods.

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도시철도 지중 콘크리트 구조물의 내진해석법 적용에 관한 연구 (A Study of seismic analysis method of urban rail transit's underground concrete structure)

  • 이희영;이동호;김은겸
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2005년도 추계학술대회 논문집
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    • pp.1159-1164
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    • 2005
  • Seismic analysis methods in use on ground structure are equivalentstatic analysis, response-displacement method and dynamic analysis etc. Equivalentstatic analysis does not considerdynamic effect, and dynamic analysis process is very complex. then 'Urbanrail transit earthquake-resistance design standard (2005.06)' is persuading that analyze by response displacement method that consider enough dynamic effect of ground structure statically. But, It is very complex and difficult to apply response-displacement method in the field. So, modified equivalentstatic analysis or pseudo static analysis that is easy to apply in the field and have rationality of design is practically used. In this study, I try to prescribe the applicable scale of structure and static analysis that have calculative effectiveness about response-displacement method by comparing and analyzing the result of each analysis method according to the scale of urban rail transit' box type concrete structure and by performing seismic analysis that apply modified equivalentstatic analysis, pseudo static analysis and response-displacement method changing the kind of ground, depth of bedrock, size of structure.

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외식프랜차이즈기업 부실예측모형 예측력 평가 (Evaluating Distress Prediction Models for Food Service Franchise Industry)

  • 김시중
    • 유통과학연구
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    • 제17권11호
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    • pp.73-79
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    • 2019
  • Purpose: The purpose of this study was evaluated to compare the predictive power of distress prediction models by using discriminant analysis method and logit analysis method for food service franchise industry in Korea. Research design, data and methodology: Forty-six food service franchise industry with high sales volume in the 2017 were selected as the sample food service franchise industry for analysis. The fourteen financial ratios for analysis were calculated from the data in the 2017 statement of financial position and income statement of forty-six food service franchise industry in Korea. The fourteen financial ratios were used as sample data and analyzed by t-test. As a result seven statistically significant independent variables were chosen. The analysis method of the distress prediction model was performed by logit analysis and multiple discriminant analysis. Results: The difference between the average value of fourteen financial ratios of forty-six food service franchise industry was tested through t-test in order to extract variables that are classified as top-leveled and failure food service franchise industry among the financial ratios. As a result of the univariate test appears that the variables which differentiate the top-leveled food service franchise industry to failure food service industry are income to stockholders' equity, operating income to sales, current ratio, net income to assets, cash flows from operating activities, growth rate of operating income, and total assets turnover. The statistical significances of the seven financial ratio independent variables were also confirmed by logit analysis and discriminant analysis. Conclusions: The analysis results of the prediction accuracy of each distress prediction model in this study showed that the forecast accuracy of the prediction model by the discriminant analysis method was 84.8% and 89.1% by the logit analysis method, indicating that the logit analysis method has higher distress predictability than the discriminant analysis method. Comparing the previous distress prediction capability, which ranges from 75% to 85% by discriminant analysis and logit analysis, this study's prediction capacity, which is 84.8% in the discriminant analysis, and 89.1% in logit analysis, is found to belong to the range of previous study's prediction capacity range and is considered high number.

Electromagnetic Forming Process Analysis Based on Coupled Simulations of Electromagnetic Analysis and Structural Analysis

  • Lee, Man Gi;Lee, Seung Hwan;Kim, Sunwoo;Kim, Jin Ho
    • Journal of Magnetics
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    • 제21권2호
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    • pp.215-221
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    • 2016
  • We conducted a phased electromagnetic forming process analysis (EFPA) over time through a coupling of electromagnetic analysis and structural analysis. The analysis is conducted through a direct linkage between electromagnetic analysis and structural analysis. The analysis process is repeated until the electric current is completely discharged by a formed coil. We calculate the forming force that affects the workpiece using MAXWELL, a commercial electromagnetic finite element analysis program. Then, we simulate plastic behavior by using the calculated forming force data as the forming force input to ANSYS, a commercial structure finite element analysis program. We calculate the forming force data by using the model shape in MAXWELL, a commercial electromagnetic finite element analysis program. We repeat the process until the current is fully discharged by the formed coil. Our results can be used to reduce the error in data transformation with a reduced number of data transformations, because the proposed approach directly links the electromagnetic analysis and the structural analysis after removing the step of the numerical analysis of a graph describing the forming force, unlike the existing electromagnetic forming process. Second, it is possible to simulate a more realistic forming force by keeping a certain distance between nodes using the re-mesh function during the repeated analysis until the current is completely discharged by the formed coil, based on the MAXWELL results. We compare and review the results of the EFPA using the peak value of the forming force that acts on the workpiece (which is the existing analysis method), and the proposed phased EFPA over time approach.

″Issues in designing a Knowledge-based system to support process modeling″

  • Suh, Eui-Ho;Kim, Suyeon
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회 2001년도 추계학술대회 논문집
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    • pp.50-54
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    • 2001
  • Information systems development entails planning, analysis, design and construction phases. The analysis phase identifying user requirements is the most important of these phases. Since unidentified defects in the early phase causes increased work and costs as development proceeds, the quality of analysis results affects the quality of the resultant system. Major tasks in the analysis phase are data modeling and process modeling. Research on building a knowledge-based system for data modeling have been conducted much, however, not sufficiently for process modeling. As a system environment with high user interaction increases, research on process modeling methods and knowledge- based systems considering such environment are required. In this research, a process modeling framework for information systems with high user interaction is suggested and a knowledge-based system for supporting the suggested framework is implemented. A proposed model consists of the following tasks: event analysis, process analysis, and event/process interaction analysis. Event analysis identifies business events and their responses. Process analysis break down the processes of an enterprise into progressively increasing details. Decomposition begins at the function level and ends when the elementary process level is reached. Event/process interaction analysis verifies the results of process analysis and event analysis. A knowledge-based system for supporting a proposed process modeling framework is implemented in a web-based environment.

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2차원 수치해석모형을 이용한 낙동강 중류구간의 하천흐름 해석 (Analysis of Hydraulic Characteristics in the Middle Reaches of Nak-Dong River using 2-Dimensional Numerical Analyis Model)

  • 한성대;최현;안창환;이제윤
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2008년도 학술발표회 논문집
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    • pp.1732-1736
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    • 2008
  • The characteristics of a river flow analysis are significant for river maintenance plan. At the present time, HEC-RAS, 1-Dimensional Numerical Analysis Model, is mainly applied to analyze the character of a river flow. The shape of a river is somewhat in longitudinal linear form. It was suspected that the usage of 1-dimensional numerical analysis model is more economical. Development of numerical analysis models and computers are possible to calculate large volume. Hence, it is possible to adapt the analysis of the key stations by 2-dimensional numerical analysis model. The limitation of 1-Dimensional Numerical Analysis Model is that it is hard to evaluate structure affection of numerical simulation by energy loss coefficient at river structure analyzing. When adaptation of the 2-dimensional numerical analysis model in river structure ensues, it takes more objective analyzing than 1-dimensional numerical analysis model for flow affection by river structure. 2-dimensional numerical analysis model consults with the different structure position of hydraulic characteristics and different water depth of shape and scope in vertical flow. 1-dimensional numerical analysis model is possible to simulate with only energy loss coefficient for sudden river section changing, sudden waterway changing by curved. 2-dimensional numerical analysis model use original geographical features. So the model removes technical subjectivity of faulty judgment. It is an objective analysis.

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