• Title/Summary/Keyword: Economic validity

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AHP Model for Selecting a Fish Farm Site (어류양식장의 입지선택을 위한 계층분석과정(AHP)모형)

  • Lee, Kang-Woo
    • The Journal of Fisheries Business Administration
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    • v.38 no.1 s.73
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    • pp.19-45
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    • 2007
  • There have not been many studies which considered both quantitative and qualitative location factors on the issues of site selection problems for a fish farm. This study develops AHP(analytic hierarchy process) model to resolve site selection problem for a fish raising farm by using quantitative and qualitative factors. In order to evaluate the validity of the location factors found in the literature review, the study used advice from fish raising farmers and related academic experts. Four major factors have been selected as economic factors, social factors, natural environmental factors and infrastructures. An AHP structural diagram has developed by considering the factors and potential sites proposed for fish farming. Through the survey on the preference of factors and potential sites, pairwise comparison matrices have been estimated and used to calculated the relative weights of each potential site. The AHP model process shown in the study can be applied to resolve site selection problems for fish raising farmers.

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Output Power Control of Wind Generation System by Machine Loss Minimization

  • Abo-Khalil Ahmed;Lee Dong-Choon
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.06a
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    • pp.51-54
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    • 2005
  • Generator efficiency optimization is important for economic saving and environmental pollution reduction. In general, the machine loss can be reduced by the decreasing the flux level, resulting in the significant reduction of the core loss. This paper proposesan model-based controller is used to decrement the excitation current component on the basis of measured stator current and machine parameters and the q-axis current component controls the generator torque, by which the speed of the induction generator iscontrolled according to the variation of the wind speed in order to produce the maximum output power. The generator reference speed is adjusted according to the optimum tip-speed ratio. The generated power flows into the utility grid through the back-to-back PWM converter. The grid-side converter controls the dc link voltage and the line-side power factor by the q-axis and the d-axis current control, respectively. Experimental results are shown to verify the validity of the proposed scheme.

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Investigation and Empirical Validation of Industry Uncertainty Risk Factors Impacting on Bankruptcy Risk of the Firm (기업부도위험에 영향을 미치는 산업 불확실성 위험요인의 탐색과 실증 분석)

  • Han, Hyun-Soo;Park, Keun-Young
    • Korean Management Science Review
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    • v.33 no.3
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    • pp.105-117
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    • 2016
  • In this paper, we present empirical testing result to examine the validity of inbound supply and outbound demand risk factors in the sense of early predicting the firm's bankruptcy risk level. The risk factors are drawn from industry uncertainty attributes categorized as uncertainties of input market (inbound supply), and product market (outbound demand). On the basis of input-output table, industry level inbound and outbound sectors are identified to formalize supply chain structures, relevant inbound and outbound uncertainty attributes and corresponding risk factors. Subsequently, publicly available macro-economic indicators are used to appropriately quantify these risk factors. Total 68 industry level bankruptcy risk forecasting results are presented with the average R-square scores of between 53.4% and 37.1% with varying time lag. The findings offers useful insights to incorporate supply chain risk to the body of firm's bankruptcy risk level prediction literature.

Evaluation of Environmental Toxicities for Priority Water Pollutants in a Small Watershed by Bioassays - Comparision between Lettuce Seed Germination Test and Microtox Bioassay - (생물학적 검정법을 이용한 소규모 수계내 수질 오염물질의 환경독성 평가 -상추씨 발아시험과 Microtox 시험 비교-)

  • 이지나;황인영
    • Environmental Analysis Health and Toxicology
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    • v.14 no.4
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    • pp.135-144
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    • 1999
  • Environmental toxicities of priority water pollutants were evaluated by two selected bioassays, Lettuce seed germination/elongation test and Microtox acute toxicity test. Toxic chemicals (heavy metals, polycyclic aromatic hydrocarbons, and phenolic compounds) inhibited the germination rate and root elongation of Lettuce seed, as well as the bioluminescence of Microtox bacteria. When test biota were exposed to target chemicals, the sensitivity of Lettuce bioassay was relatively lower than that of Microtox bioassay. However, Lettuce bioassay may be a good candidate for prescreening the environmental toxicities of priority water pollutants, since the testing method with Lettuce seed was relatively easier and more economic than with Microtox bacteria. Toxicity tests were conducted to compare the validity and sensitivity of both bioassays for sediment from a small stream passed through urban area as well as leachate from a municipal solid waste landfill. From experimental results, we found that Lettuce test and Microtox test are compensated each other as a battery of bioassay for evaluating the environmental toxicities of field samples obtained from a small stream contaminated by pollutants.

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Building a Product Design of Innovative Strategy for Creating Enterprise Development

  • Liao, Shih-Chung
    • The Journal of Industrial Distribution & Business
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    • v.5 no.1
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    • pp.17-25
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    • 2014
  • Purpose - Nowadays, the innovative design concept is being implemented in product design. In order to satisfy market trends and the demand for quality, designers should employ customer satisfaction questionnaires and analyze them with various experimental processes. Research design, data, and methodology - These methodologies would help designers have a better understanding of their customers and judge the market size and clustering validity, by diverse product strategies, for dealing with the rapid change prevailing in the market today. Results - By considering the innovative design with regard to telephones as an experimental case, the study investigates and demonstrates how the product can benefit from market-oriented and customized management concepts, when creative design ability is utilized for developing the product. Conclusions - Along with the benefit of having an innovative product value, the product can stimulate progress inthe development of the enterprise management, which has emerged as the main issue in the area of social and economic development in every developed country.

A Case Study on Simplified Assessment Method for Site Selection of the Waste Treatment Facilities (폐기물처리 시설 입지선정 효율화 방안을 위한 사례연구)

  • 장성호;손영일
    • Journal of environmental and Sanitary engineering
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    • v.15 no.2
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    • pp.85-94
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    • 2000
  • The comparative evaluation is the most effective method for site selection because the selection of waste treatment facility is to determine the optimum site out of limited candidate sites. This study adopted the ordinal scale evaluation, one of methods of comparative evaluation. The ordinal scale evaluation aims to determine the investigating items referring to the character of sites, to determine the importance factors for investigating items, and to determine the optimum site according to the quantitative evaluation. This study has focussed on reflecting the opinion of residents to the maximum extent with a weight on social and economic aspects, considering the state of confrontation against each other between the autonomous government organization and local residents, which is being emerged as a social issue relating to the evaluation rating on each item of site selection of an optimum site. Therefore, rational, and clear validity investigations and proper reduction of both time and expenses in site selection as well through this a study.

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음압을 이용한 선삭공정 상태 감시 및 제어

  • 이성일;정성종
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.269-273
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    • 1997
  • In order to maker unmanned machining systems with satisfactory performances, it is necessary to incorporate appropriate condition monitoring systems in the machining workstations to provide the required intelligence of the expert. This paper deals with condition monitoring for chatter, tool wear and fracture during turning operation. To develop economic sensing and identification methods for turning processes, sound pressure measurement and digital signal processing technique were proposed. We suppressed chatter by stability control methodology, which was studied through manipulation of spindle speeds regarding to chatter frequencies. It was shown that tool wear and fracture were identified and to be estimated by using the wear indices. The validity of the proposed system was confirmed through the large number of cutting tests.

Condition Monitoring of Tool wear using Sound Pressure and Fuzzy Pattern Recognition in Turning Processes (선삭공정에서 음압과 퍼지 패턴 인식을 이용한 공구 마멸 감시)

  • 김지훈
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1998.10a
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    • pp.164-169
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    • 1998
  • This paper deals with condition monitoring for tool wear during tuning operation. To develop economic sensing and identification methods for turning processes, sound pressure measurement and digital signal processing technique are proposed. To identify noise sources of tool wear and reject background noise, noise rejection methodology is proposed. features to represent condition of tool wear are obtained through analysis using adaptive filter and FFT in time and frequency domain. By using fuzzy pattern recognition, we extract features, which are sensitive to condition of tool wear, from several features and make a decision on tool wear. The validity of the proposed system is condirmed through the large number of cutting tests in two cutting conditions.

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Finite element simulation of sheet metal forming by using non-parametric tool description with locally refined patches (국소 분할된 패치를 갖는 비매개변수 금형묘사법을 이용한 3차원 박판성형공정해석)

  • 윤정환;양동열;유동진
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1995.03a
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    • pp.162-169
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    • 1995
  • An improved nonparametric tool description based on successive refined monparametric patches is proposed and therlated criterion for refinement is also discussed . In the proposed sheme, any required order of tool surface conformity can be achieved by employing successive refinements accoring to the suggested criterion. By using the suggested adaptive tool refinement technique based on the nonparametric patch tool description, the locally refined nonparametric tool surface with economic memory size and sufficient accuracy as well as with favorable charateristics for contact treatment can be obtained directly form the parametric patch related with commerical CAD system. Computation is carried out for a chosen complex sheet forming example of an actual autobody panel in order to verify the validity and the efficiency of the developed tool surface description.

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Compressive Strength of Horizontal Joints Pocket in Precast Concrete Large Panel System (대형판 PC 구조 시스템의 수평접합부 충전부위 구조성능에 관한 실험연구)

  • Yoo, Seong-Hoon;Cho, Seung-Ho;Park, Hyun-Soo;Euh, Yang-Suk;Chung, Lan
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.10a
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    • pp.597-602
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    • 1997
  • The compressive strength of horizontal joints in precast concrete large panel structures depends on parameters such as grout and panel strength, detail of joint, joint moment, width of grout column etc. As the panels are only connected at the pocket, it results in the reduction of compressive strength area. The purposes of this study are to develop the suitable grout material the joint pocket and to enable us to evaluate structural capacity. The validity of the design formulas provides us more economic system in construction. Test results of 15 specimens show that the proper construction procedure and grouting material develop the sufficient compressive strength of the wall as monolithic system.

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