• 제목/요약/키워드: small area model

검색결과 1,025건 처리시간 0.023초

Bayesian hierarchical model for the estimation of proper receiver operating characteristic curves using stochastic ordering

  • Jang, Eun Jin;Kim, Dal Ho
    • Communications for Statistical Applications and Methods
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    • 제26권2호
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    • pp.205-216
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    • 2019
  • Diagnostic tests in medical fields detect or diagnose a disease with results measured by continuous or discrete ordinal data. The performance of a diagnostic test is summarized using the receiver operating characteristic (ROC) curve and the area under the curve (AUC). The diagnostic test is considered clinically useful if the outcomes in actually-positive cases are higher than actually-negative cases and the ROC curve is concave. In this study, we apply the stochastic ordering method in a Bayesian hierarchical model to estimate the proper ROC curve and AUC when the diagnostic test results are measured in discrete ordinal data. We compare the conventional binormal model and binormal model under stochastic ordering. The simulation results and real data analysis for breast cancer indicate that the binormal model under stochastic ordering can be used to estimate the proper ROC curve with a small bias even though the sample sizes were small or the sample size of actually-negative cases varied from actually-positive cases. Therefore, it is appropriate to consider the binormal model under stochastic ordering in the presence of large differences for a sample size between actually-negative and actually-positive groups.

The detection and diagnosis model for small scale MSLB accident

  • Wang, Meng;Chen, Wenzhen
    • Nuclear Engineering and Technology
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    • 제53권10호
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    • pp.3256-3263
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    • 2021
  • The main steam line break accident is an essential initiating event of the pressurized water reactor. In present work, the fuzzy set theory and the signal-based fault detection method has been used to detect the occurrence and diagnosis of the location and break area for the small scale MSLB. The models are validated by the AP1000 accident simulator based on MAAP5. From the test results it can be seen that the proposed approach has a rapid and proper response on accident detection and location diagnosis. The method proposed to evaluate the break area shows good performances for small scale MSLB with the relative deviation within ±3%.

HGLM과 EB 추정법을 이용한 질병지도의 작성 (HGLM and EB Estimation Methods for Disease Mapping)

  • 김영원;조나경
    • 응용통계연구
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    • 제17권3호
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    • pp.431-443
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    • 2004
  • 본 연구에서는 질병지도작성(disease mapping)을 위해 인접지역의 정보를 효과적으로 활용할 수 있는 EB(empirical Bayes) 추정 법과 HGLM(hierarchial generalized linear model)을 기초로 한 추정법을 다룬다. 사례연구로 이 추정방법들을 이용하여 2000년 사망원인통계자료를 이용해 경상도 및 전라도의 112개 시$.$$.$구 단위 행정자치구역별 45세 이상 폐암 사망률을 산출하고, 경상도 및 전라도 지역 폐암 사망률 지도를 작성한다. 아울러 제시된 방법들에 위해 얻어진 추정치들의 변동과 3년간 평균 사망률을 기준으로 구한 MSD(mean square deviation)를 이용하여 추정방법들의 특성을 비교 분석한다.

접촉식 시일장치의 밀봉 접촉면 형상에 대한 최적화 설계연구 (Optimization Design on the Sealing Surface Profiles of Contacting Seal Units)

  • 김청균
    • 한국생산제조학회지
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    • 제20권6호
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    • pp.761-766
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    • 2011
  • In this study, the optimized design profiles between a seal ring and a seal seat of contacting seal units has been proposed based on the FEM computed results. The maximum temperatures, the thermal distortions in axial and radial directions, and maximum contact normal stresses between a seal ring and a seal seat have been analyzed for various contact sealing profiles. The FEM computed results present that the contact area between seal rings and seal seats is very important for a good tribological performance such as low friction heating, low wear, high contact normal stress in a primary sealing components. The seal surface model III in which has a small sealing contact area shows low dilatation of primary sealing components, and high contact stress between a seal ring and a seal seat. This model with small contact surface of a seal ring produces high friction heating and contact stress. But the model III produces very small deformations of contacting sealing surface because of high convection heat transfer by cooling water circulation around the seal ring surface. Thus, the analysis results recommend a short width of a primary sealing unit rather than a big width of contact surfaces of contacting seal units for reducing a leakage and axial deformation of primary seal components.

선형 Model에 의한 소류역에 있어서의 무차원 단위도 유도에 관한 연구 (A study on the derivation of Dimensionless Unit Hydrographs by the Linear model in the small watersheds)

  • 이순혁;한중석
    • 한국농공학회지
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    • 제23권3호
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    • pp.78-87
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    • 1981
  • This study was attempted to get dimensionless unit hydrograph by linear model which can be used to the estimation of flood for the development of Agricultural water resources and laid emphasis on the application of dimensionless unit hydrographs for the ungaged watersheds by applying linear model. The results summarized through this study are as follows. 1.Peak discharge is found to be Qp= CAR (C =0. 895A-o.145) having high significance between peak discharge, Qp and effective rainfall, R within the range of small watershed area, 84 to 470km2. consequently, linearity was acknowledged between rainfall and runoff. Reasonability is confirmed for the derivation of dimensionless unit hydrograph by linear model. 2.Through mathematical analysis, formula for the derivation of dimensionless unit hydrograph was derived. qp--p=(tp--t)n-1[e-(n-1)](tp--t-1) 3.Moment method was used for the evaluation of storage constant, K and shape parameter, n for the derivation of dimensionless unit hydrograph. Storage constant, K is more closely related with the such watershed characteristics as length of main stream and slopes. On the other hand, the shape parameter, n was derived with such watershed characteristics as watershed area, river length, centroid distance of the basin and slopes. 4.Time to peak discharge, Tp could be expressed as Tp=1. 25 (√s/L)0.76 having a high significance. 5.Dimensionless unit hydrographs by linear model stood more closely to the observe dimensionless unit hydrographs On the contrary, dimensionless unit hydrographs by S.C. S. method has much difference in comparison with linear model at the falling limb of hydrographs. 6.Relative errors in the q/qp at the point of 0.8 and 1.2 for the dimensionles ratio by linear model and S. C. S. method showed to be 2.41, 1.57 and 4.0, 3.19 percent respectively to the q/qp of observed dimensionless unit hydrographs. 7.Derivation of dimensionless unit hydrograph by linear model can be accomplished by linking the two empirical formulars for storage constant, K, and shape parameter, n with derivation formular for dimensionless unit hydrograph for the ungaged small watersheds.

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중소 패션기업의 업무영역별 비즈니스 윤리 요소 도출 (Identifying business ethics components according to business area for small and medium-sized fashion companies)

  • 김수경;여은아
    • 복식문화연구
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    • 제27권5호
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    • pp.415-432
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    • 2019
  • The purpose of the present study was to generate a list of business ethics components according to business area for small and medium-sized fashion companies. Based on the literature review, 21 components of business ethics components were identified within five business areas. Ten CEOs(Chief Executive Officers) each participated in an in-depth interview, sharing ethical and unethical cases from their own businesses. Constant comparative analysis was used to generate important business ethics components from those cases. In results, important business ethics components for each business area are: 1) using human-friendly materials, strengthening sustainable technologies, using vegan materials, concerning safe process, and reducing waste in the material production and sourcing area, 2) enhancing an efficiency in design, developing recycle/reuse designs, avoiding to copy designs, and using messages for public interest in the product design area, 3) concerning fair-trade, reducing harmful substance, saving energy, and using ethical supply channels in the distribution and logistics area, 4) acquiring certifications, promoting consumer protection, avoiding exaggerative/false advertisements, and promoting social contributions in the management and marketing area, and 5) promoting workers' rights, complying with the law, and investing on employee educations in the labor management area. All of the ethical and unethical cases of the ten companies have involved aspects of the 21 components, thereby enhancing understandings on how each issue is being seriously considered and/or handled in the small and medium-sized fashion companies. Study findings may provide a basis for development of a research model for quantitative studies and/or educational programs related to business ethics in the fashion industry.

중규모 바람장 해석을 위한 Fine Mesh Model의 구성 (Composition of Fine Mesh Model for Explication of Mesoscale Wind Field)

  • 이화운;김유근
    • 한국환경과학회지
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    • 제4권2호
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    • pp.159-168
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    • 1995
  • To predict reasonably the movement and the concentration of the pollutants in the coastal area. A simulation model should be prepared considering detail topography with land-sea and the urban effects, and the resolution near the source. The explicit method can not be applied due to the instability of the numerical calculation in high horizontal-grid resolution, while the ADI scheme satisfied with the high horizontal grid resolution and can be used in the fine mesh system which shows the detail topography, atmospheric flow The ADI method which studied the high horizontal grid resolution was excellent. The two dimensional model used in the study using ADI method is proved as a reasonable model to predict the wind field in any small scale area including mountainous coastal urban area.

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해양플랜트 거주용 부선 실내공간계획 연구 (A Study on Interior Space Planning of Accommodation Barge for Offshore Plant)

  • 이한석;강영훈;도근영
    • 한국실내디자인학회논문집
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    • 제20권4호
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    • pp.201-210
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    • 2011
  • This study is on the space planning of accommodation area in accommodation barge, which is a kind of offshore plant supply vessel providing workers with exclusive accommodation facilities. Firstly, the space layout of accommodation area is analyzed using the general arrangement drawings of 10 actually-built accommodation barges currently in use. Secondary, the design guides and standards for living quarters of offshore plants issued from overseas classification societies such as ABS, NORSOK etc. are analyzed and based on the analysis design guidelines for accommodation area of accommodation barge are newly suggested. Thirdly, a model of accommodation area in accommodation barge is set up and space arrangements and movement lines for each deck of the accommodation area of the model are planned. Fourthly, cabins, dinning room and galley, recreation spaces, and sanitary spaces of the accommodation area of the model are planned. The results of this study may be summarized as follows. An accommodation barge has 'barge deck' for small scale work and material storage, and 'accommodation area' for the living and resting of workers. The accommodation area is made of workers accommodation sector, service sector, crew sector and business sector. The interior design guidelines for accommodation area of accommodation barge should be made soon by Korea Register of Shipping.

다중 회귀분석 기반 도시형 생활주택의 공사기간 산정 모델 개발 (Development of a Model for Calculating the Construction Duration of Urban Residential Housing Based on Multiple Regression Analysis)

  • 김준상;김영석
    • 토지주택연구
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    • 제12권4호
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    • pp.93-101
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    • 2021
  • 국내 소규모 가구가 점차적으로 증가함에 따라 소규모 가구를 위한 주거공급 정책에 대한 중요성이 높아지고 있다. 이러한 중요성에 따라 정부에서는 소규모 가구를 위한 도시형 생활주택을 지속적으로 공급해오고 있다. 도시형 생활주택은 공동주택, 일반 업무시설과 동일하게 분양 및 임대 사업이므로 발주자는 프로젝트 기획단계에서 적정공사기간을 산정하는 것은 중요하다. 그러나, 선행연구에서는 대규모 건축물의 공사기간을 산정할 수 있는 모델이 존재하나 도시형 생활주택과 같은 소규모 건축물에 대한 적정 공사기간 산정 모델은 부재한 것으로 분석되었다. 따라서 본 연구의 목적은 기획단계에서 발주자가 적정 공사기간을 산정할 수 있는 다중 회귀분석 기반 도시형 생활주택의 공사기간 산정 모델을 개발 및 검증하는 것이다. 개발된 모델에 입력되는 독립변수는 연면적, 수도권, 지하층수, 지상층수, 주 건축물 수, 강원권의 총 6개이며, 개발된 모델의 수정된 결정계수(Ra2)는 0.547로 분석되었다. 개발된 모델의 성능은 RMSE의 경우 171.26일, MAPE의 경우 26.53%로 도출되었다. 본 연구를 통해 개발된 모델은 발주자에게 신뢰성 있는 공사기간 산정 결과를 제공할 수 있을 것으로 기대된다.

중소기업을 위한 프로젝트 수행역량 평가모델 (A Project Competency Assessment Model for Small and Medium Enterprises)

  • 임형정;백동현
    • 산업경영시스템학회지
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    • 제35권3호
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    • pp.32-44
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    • 2012
  • The competitiveness of modern organizations highly depends upon organizational competencies rather than individual competencies. However, most of previous studies on project success focused on individual competencies, such as project manager's competency and leadership. Even though there are some assessment models for the organizational project competencies, they are limited in specific organizations and industries. Furthermore, it is difficult to apply them to domestic companies, especially to small and medium enterprises because some assessment items are inappropriate for them. The purpose of this study is to propose an organizational project competency assessment model that is suitable for evaluating small and medium enterprises. First, the assessment areas and items for each area are determined through extensive investigation of previous models including OPM3, CMMI, and PMBOK. Next, the weights of assessment areas and items are decided by AHP analysis of experts response in the field of the project management. Finally, a project competency assessment model with assessment sheets is proposed. The model proposed in this study might support managers of small and medium enterprises to find pros and cons of project competencies and to establish improvement plans.