• 제목/요약/키워드: case study methodologies

검색결과 348건 처리시간 0.023초

신제품 수요예측 방법론 연구 (A Study on the New Product Forecasting Methodology)

  • 임종인;오형식
    • 대한산업공학회지
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    • 제18권2호
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    • pp.51-63
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    • 1992
  • It is commonly accepted that the demand forecasting data play a vital role in deciding strategic variables such as the optimal market entry time, the price structure and the production capacity etc. In case of the new product, however, it is hard to apply the well known regression-type methodologies. In this study, we survey the characteristics of various types of new product demand forecasting(NPDF) methodologies which are useful in case the historical data are not available. Further, we explore the possibility of incorporating the NPDF methodologies and develope the unified infra-structure of the NPDF methodologies. Finally we propose an integrated prototype of the NPDF model.

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Improvement in the DNBR Modeling of RETRAN for Safety Analyses of Westinghouse Nuclear Power Plants

  • Cheong, Ae-Ju;Kim, Yo-Han
    • Nuclear Engineering and Technology
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    • 제34권6호
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    • pp.596-609
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    • 2002
  • Korea Electric Power Research Institute has developed the in-house safety analysis methodologies for non-LOCA(Loss Of Coolant Accident) events based on codes and methodologies of vendors and Electric Power Research Institute . According to the new methodologies, analyses of system responses and calculation of DNBR(Departure from Nucleate Boiling Ratio) during the transient have been carried out with RETRAN code and a sub-channel analysis code, respectively. However, it takes too much time to calculate DNBR for each case using the two codes to search for the limiting case from sensitivity study. To simplify the search for the limiting case, accordingly, RETRAN code has been modified to roughly calculate DNBR using hot channel modeling. The W-3 correlation is already included in RETRAN as one of the auxiliary DNBR models. However, WRB-1 and WRB-2 correlations required to analyze some Westinghouse type fuels are not considered in RETRAN DNBR models. In this paper, the RETRAN DNBR models using the correlations have been developed and the partial and complete loss of forced reactor coolant flow events have been analyzed for Yonggwang units 1 and 2 with the new methodologies to validate the models. The results of the analyses have been compared with those mentioned in the chapter 15 of the Final Safety Analysis Report.

개념 설계 도구로써의 공리적 설계와 트리즈의 상호보완 (A Review of TRIZ combined with Axiomatic Design Methodologies)

  • 안영준;이경원
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.848-854
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    • 2005
  • In mechanical design part, though many design methodologies have been developed, most of them are applicable for detailed design. Therefore, when people had to do conceptual design, they relied on their individual creativity. To improve this phenomenon, some methodologies are developed such as TRIZ and axiomatic design. In this paper, both TRIZ and axiomatic design methodologies will be reviewed. In addition, some papers which contain conceptual design case study will be also dealt with. These case studies are results of application both axiomatic design and TRIZ methodology.

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COBDA-콘크리트 교량의 노후화를 평가하는 전문가 시스템 (COBDA-An Expert System for Concrete Bridge Deterioration Assessment)

  • 김경수
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1996년도 가을 학술발표회 논문집
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    • pp.532-539
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    • 1996
  • Existing assessment methodologies present a considerable problem because of fuzzy situation of deterioration mechanism of concrete bridges; namely, qualitative, subjective or inconsistent. This paper discusses current assessment methods in aspect of uncertainty. The expert system, COBDA, is developed for consistent and fast assessment of deteriorantion of concrete bridges. Briefly introduced in this paper are the structure of expert system and several methodologies for decision making of deterioration situation and providing repair option. COBDA is configured by PROLOG for logic approach and expert system shell based on Bayesian subjective probability. The methodologies are illustrated and discussed by comparison of condition assessment results in a case study.

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A Review of Stream Assessment Methodologies and Restoration: The Case of Virginia, USA

  • Bender, Shera M.;Ahn, Chang-Woo
    • Environmental Engineering Research
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    • 제16권2호
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    • pp.69-79
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    • 2011
  • Rapid population growth and land use changes have severely degraded streams across the United States. In response, there has been a surge in the number of stream restoration projects, including stream restoration for mitigation purposes. Currently, most projects do not include evaluation and monitoring, which are critical in the success of stream restoration projects. The goal of this study is to review the current status of assessment methodologies and restoration approaches for streams in Virginia, with the aim of assisting the restoration community in making sound decisions. As part of the study, stream restoration projects data from a project in Fairfax County, Virginia was assessed. This review revealed that the stream assessment methodologies currently applied to restoration are visuallybased and do not include biological data collection and/or a method to incorporate watershed information. It was found from the case study that out of the twenty nine restoration projects that had occurred between 1995 and 2003 in Fairfax County, nineteen projects reported bank stabilization as a goal or the only goal, indicating an emphasis on a single physical component rather than on the overall ecological integrity of streams. It also turned out that only seven projects conducted any level of monitoring as part of the restoration, confirming the lack of evaluation and monitoring. However, Fairfax County has recently improved its stream restoration practices by developing and incorporating watershed management plans. This now provides one of the better cases that might be looked upon by stakeholders when planning future stream restoration projects.

Introduction to Industrial Applications of Low Power Design Methodologies

  • Kim, Hyung-Ock;Lee, Bong-Hyun;Choi, Jung-Yon;Won, Hyo-Sig;Choi, Kyu-Myung;Kim, Hyun-Woo;Lee, Seung-Chul;Hwang, Seung-Ho
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제9권4호
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    • pp.240-248
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    • 2009
  • Moore's law has driven silicon technology scale down aggressively, and it results in significant increase of leakage current on nano-meter scale CMOS. Especially, in mobile devices, leakage current has been one of designers' main concerns, and thus many studies have introduced low power methodologies. However, there are few studies to minimize implementation cost in the mixed use of the methodologies to the best of our knowledge. In this paper, we introduce industrial applications of low power design methodologies for the decrease of leakage current. We focus on the design cost reduction of power gating and reverse body bias when used together. Also, we present voltage scale as an alternative to reverse body bias. To sustain gate leakage current, we discuss the adoption of high-$\kappa$ metal gate, which cuts gate leakage current by a factor of 10 in 32 nm CMOS technology. A 45 nm mobile SoC is shown as the case study of the mixed use of low power methodologies.

Determinants of Foreign Direct Investment: Evidence from Provincial Level Data in Indonesia

  • MEIVITAWANLI, Bryna
    • The Journal of Asian Finance, Economics and Business
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    • 제8권5호
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    • pp.53-60
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    • 2021
  • Foreign direct investment (FDI) is especially important for developing countries. This study investigates the determinants of FDI in the case of Indonesia. Most empirical researches in this field used time series data of a single country or panel data of several countries. Although panel data analysis is more comprehensive, however results taken from cross-country analysis cannot be directly applied to any specific country in the dataset and therefore lacks practicality. In this research, panel data analysis of a single country is performed to overcome the aforementioned shortcomings. Five determinants of FDI are tested using panel data of 33 Indonesian provinces over 10-year period of time. Two methodologies are adopted, random/fixed effects model and Granger Causality. The results show that only market size significantly affects FDI when tested using both methodologies. Human capital and financial market development show significant result in one of the two methodologies. While, economic growth and infrastructure did not show any significant results at all. This research stresses the importance of comprehensive single country analysis since only one out of five commonly discussed determinants is applicable in the case of Indonesia. Governments should therefore carefully reconsider the use of cross-country analysis as a basis of their policy formulations.

국내 산림탄소상쇄 운영표준 및 VCS 방법론에 따른 산림경영 사업의 산림탄소흡수량 차이 분석 - 벌기령 연장 사업 방법론을 중심으로 - (Analysis of Forest Carbon Offset Credits from Forest Management Project based on to the Korean Forest Carbon Offset Standard and the VCS Methodology - Case Study on the Methodology for Forest Management through Extension of Rotation Age -)

  • 김영환
    • 한국기후변화학회지
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    • 제8권4호
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    • pp.369-375
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    • 2017
  • In this study, it was intended to compare the two methodologies for forest management project through extension of rotation age: Korean Forest Carbon Offset Standard (KFOS) and Verified Carbon Standard (VCS). The amount of carbon removals and offset credits based on the two methodologies and their trends were analyzed in this study. The major difference between two methodologies were found at the process of estimation of baseline carbon removals. For instance, average carbon stock during the project period was used for estimation of baseline carbon removals in KFOS, while average carbon stock change during the 100 years was used in VCS. Due to the different approach for estimation of baseline carbon removal, the estimated offset credits were also different according to the two methodologies. In this study, 15 project scenarios were considered for comparison of two methodologies : 5 major coniferous stands in Korea (Pinus densiflora in Gangwon region, Pinus densiflora in Central region, Pinus koraiensis, Larix leptolepis, Chamaecyparis obtusa) with 3 project periods (30, 35, 40 years). The results showed that estimated carbon offset credits based on the KFOS methodology were higher for all 15 scenarios compared to those based on the VCS methodology. The KFOS showed a steep decline in the annual offset credit as project period gets longer, thus it is not desirable for projects with longer period. VCS is more acceptable for longer projects with a small difference according to the project periods. The results also indicated that Pinus densiflora in Gangwon, Pinus koraiensis, and Larix leptolepis are more desirable species for forest management project through the extension of ration age.

단일 센서(Single Sensor)를 활용한 차량속도 추정에 관한 연구 (Estimation of Individual Vehicle Speed Using Single Sensor Configurations)

  • 오주삼;김종훈
    • 대한토목학회논문집
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    • 제26권3D호
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    • pp.461-467
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    • 2006
  • 노면에 차량 검지센서를 설치하여 개별차량의 속도자료를 수집하는 경우, 일반적으로 일정거리가 이격되게 설치한 두 개 이상의 차량 검지센서간의 반응시간을 활용하여 차량의 속도를 산출하게 된다. 본 논문에서는 차로당 센서 1개만을 설치하여 개별차량의 속도 산출을 함에 있어, 기존 방법인 파형의 기울기를 이용하여 속도 추정하는 방법(Case 1)과 평균차량길이를 적용한 속도산출(Case2), 새로 고안한 방법인 단일 테이프스위치(Tape Switch) 센서를 수평형으로 설치하고 평균축거를 적용하여 속도 추정하는 방법(Case 3), 그리고 테이프스위치 센서를 사선형으로 설치하고 차량의 평균윤거(Mean of tread)를 적용하여 속도 추정하는 방법(Case 4)에 대한 속도 추정정확도를 평가하였다. 4가지 방식 각각에 대해 현장에서 센서를 설치하고 기준값과 속도추정 값을 비교 분석을 했으며, 평가지표로는 등가계수(Equality Coefficient), 절대오차백분율(MAPE)을 통하여 평가하였다. 평가결과는 Case1 > Case 4 > Case 2, 3 순으로 양호한 결과를 보이는 것으로 분석되었다.

국내.외 이전적지 활용 사례에 관한 비교연구 (A Comparative Study on the Development Cases of Relocated Urban Sites at Home and Abroad)

  • 이화룡;동재욱;김진수
    • 한국디지털건축인테리어학회논문집
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    • 제11권4호
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    • pp.47-56
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    • 2011
  • In recent years, the change of urban function and the decrease in birth rate have given rise to merge, abolition and relocation of the existing building in cities. This study explores the possibilities for various land utilizations of relocated urban sites. In doing so, it compares the development methods and the utilization pattern between home and abroad. It analyses the land use categories and the development methodologies of 4 relocated urban sites happened in Seoul and 4 foreign sites. In addition, it analyzes the land utilization after relocation, development principals, area, building usage and changes in land use regulation. Finally, it proposes the directions for developing relocated site and each of roles among the parties concerned. This study concludes that it is available to exploit the relocated urban sites by the variety of development methodologies, especially in a metropolis like Seoul.