• Environmental and Resource Economics Review
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• v.13 no.1
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• pp.1-32
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• 2004

Environmental Performance Index(EPI) has shown some limitation. Since it has lack of analysis for the relation between environmental performance and business performance, and public information. Therefore it could not provide valuable information for the shareholders to decide for the investment. In this paper by using Analystic Hierarchy Process (AHP), EPI was calculated giving some weighted scale for each environmental items. Improvement of pollution treatment, general management data such as EMS system, and environmental improvement for the products and process were the main three items when decision makers in bankings are considering the investment for a company. In empirical case, companies which has Environmental-Friendly Coorperation Award from MOE and ISO 14001 certification had shown strong relation between business performance and environmental performance.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.5
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• pp.506-517
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• 2000

In distributed real-time system, a task activated by the completion of its preceding task can be modeled as a periodic task with activation jitter. An activation jitter of a task is defined asthe difference between the worst case and the best case response time of its preceding task. Becausethe existing approaches assume that the best case response time is much smaller than the actual one,the activation jitter and the worst case response time of lower priority tasks are overestimated. Thispaper proposes a new analysis technique to calculate the best case response time more precisely andto reduce the activation jitter bounds. The proposed technique obtains the best case response time byconsidering the relative phase between tasks. The precise analysis of the activation jitters can reducethe worst case response time of other tasks and increase the schedulability. The simulation resultsshow that the proposed analysis technique improves the accuracy of the best case and the worst caseresponse time up to 40% and 6%, respectively.

• Journal of the Korean Society for Railway
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• v.12 no.6
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• pp.921-926
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• 2009

The RPN provides information which includes the risk level and the priority order of maintenance tasks for components. However, if there is no sufficient historical failure data, the historical failure data from other sources can be applied to the target system. And if we use historical data from other sources without any process, there will be concomitant problems according to a discord of each system characteristic, a difference between the present and the date of failure data, etc. In this paper, a new methodology is proposed to model the failure rate as a fuzzy function to resolve these problems. Taking advantage of this result, the RPN can be calculated by using the fuzzy operation. The proposed method is applied to the substation system.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1713-1716
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• 2008

최근 배출되는 미량유해물질로 1991년 페놀, 2004년 1,4-다이옥산, 2006년 퍼클로레이트 검출 등 빈번하게 원수수질 오염사고가 발생하고 새로운 미량유해 화학물질의 배출이 우려됨에 따라, 일부 시민단체, 시의회, 언론 등에서 깨끗하고 안전한 상수원수 확보를 위한 근본적인 대책을 요구하는 목소리가 커지고 있다. 이에 대한 대책의 일환으로 취수원 이전에 대한 타당성 등이 검토되고 있다. 이러한 요구를 바탕으로 본 연구에서는 K-WEAP 모형을 이용하여 낙동강수계 물수지 분석을 실시하였다. 관련된 기존자료를 이용하여 용수수요량을 산정하였으며, 갈수량시 물수지 분석을 실시하였다. 연구에 사용된 K-WEAP 모형은 SEI-B(Srockholm Environment Institute, Boston Center)에서 개발된 WEAP에 기반을 두고 우리나라에 특성에 맞게 모의형태를 개선하고 한글화한 모형으로 분석대상 지역으로서 도시지역과 농업지역, 단일 소유역이나 복잡한 하천유역의 물 수요-공급 시스템에 적용할 수 있다. 또한 K-WEAP 모형은 용수목적별 수요량 분석, 물 절약, 수리권과 배분 우선순위, 지하수와 하천유량 모의, 저수지 운영, 수력발전, 오염물질 추적, 생태계 필요수량 분석과 같은 광범위한 부문의 문제들까지 다룰 수 있다. 본 연구에서 물수지 분석에 사용된 대상구간은 낙동지점에서 고령교지점까지 약 120km이며, 낙동강에 유입되는 지류로는 감천과 금호강을 대상에 포함하였다. 대상구간에 대해서는 3가지의 시나리오를 바탕으로 모의를 진행하였다. 선정된 3가지 시나리오는 현재의 대구 인근지역의 취수와 방류를 고려하는 상태와 현실가능성이 있는 2가지의 대안에 대해서 분석을 실시해 보았다. 대안들은 각각의 대구 취수시설을 구미 상류로 이전하여 취수하는 상황과 구미지역 및 칠곡지역의 방류구 시설을 하류로 이전하여 방류하는 상황으로 가정하여 분석을 실시하였다. 분석결과 현재 상태의 시나리오에서만 갈수기시 만족할 만한 결과를 보여주었고 나머지 2가지의 시나리오에서는 유량이 부족함을 나타났다. 현재의 상태를 모의한 시나리오를 제외한 시나리오의 분석에서는 갈수기 시에 물 부족을 겪게 된다. 이는 낙동강 상류에서 추가방류가 없으면 해결되지 못하는 상황으로 다른 대안들(신규 댐 방류 등)에 대한 추가적인 시나리오 분석이 필요할 것으로 판단된다.

• Journal of Navigation and Port Research
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• v.38 no.6
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• pp.637-643
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• 2014

This study aims to explore a set of indicators to be used for purification management. by estimating the total quantity of depositied waste in coastal waters, Through 3 rounds of Delphi technique, this study sorts out the following 5 variables to be used as major indicators determining priorities for purification in coastal areas: the ratio of re-deposition after collection, the area where fishing gear are lost, the total quantity of depositied waste of each coastal water, the total quantity of deposited waste in the past, and the quantity of depositied waste by unit area. Although the fact that the delphi surveys were done only on 27 specialists limits its external validity, this study will serve as a base for in-depth studies with more expanded panels that will provide better indicators for purification management in coastal waters of Korea.

• Journal of Korea Water Resources Association
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• v.51 no.11
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• pp.959-969
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• 2018

The aging water pipes induce various problems, such as water supply suspension due to breakage, insufficient water pressure, deterioration of water quality, damage by sink holes, and economic losses due to water leaks. However, it is impractical and almost impossible to repair and/or replace all deteriorated water pipes simultaneously. Hence, it is required to quantitatively evaluate the deterioration rate of individual pipes indirect way to determine the rehabilitation order of priority. In this study, ANN(Artificial Neural Network)-Clustering method is suggested as a new approach to assess and assort the water pipes. The proposed method has been applied to a water supply network of YG-county in Jeollanam-do. To assess the applicability of the model, the evaluation results were compared with the results of the Numerical Weighting Method (NWM), which is being currently utilized in practice. The assessment results are depicted in a water pipe map to intuitively grasp the degree of deterioration of the entire pipelines. The application results revealed that the proposed ANN-Clustering models can successfully assess the water pipe deterioration along with the conventional approach of NWM.

• International Journal of Highway Engineering
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• v.8 no.4 s.30
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• pp.145-157
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• 2006

Generally, the method of the policy analysis has been used for making a policy decision of the development project of the road through the expert interview based on AHP. According to introducing PI, the study of the method of the integrating process for various opinion of the related groups is required. On this study I evaluate what is a difference between the results of integrated process and the AHP analysis on what is major considering factor in decision-making process. From the analysis, each evaluate factor is in level of significance by ANOVA. First, there is a significance level difference between Group A, C and Group B Second, there is also a significance level difference on the result of AHP analysis for each group in order to evaluate by integrated method. Finally, the method of AHP analysis which considers priority factor is expected as to be useful tool on decision-making of various group.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.4
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• pp.27-36
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• 2018

Although the current evaluation system has been revised four times since it was revised in 1996, it is insufficient to utilize it as a basis for predicting the performance degradation from the long-term viewpoint and prioritization decision for the budget input due to the evaluation system limited to securing the structural safety. Therefore, this study proposes a new evaluation system suitable for the performance evaluation of conventional (ASSM) tunnels among the various types of existing road tunnels using Delphi technique and AHP technique. Since the existing evaluation systems and evaluation items in domestic and overseas are limited in scope of evaluation criteria, the survey was conducted in conjunction with closed questionnaires on existing items and open questionnaires for eliciting new items. The validity of the questionnaire results were verified and the performance evaluation factors suitable for conventional (ASSM) tunnels were derived. After calculating weighted value of the derived evaluation item using AHP technique, a new evaluation system is proposed to meet the characteristics of the ASSM tunnel, so that they can be used as reference materials for revising and supplementing detailed guidelines of performance evaluation in the future.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.1 s.9
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• pp.27-40
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• 1997

Recently, with the demand for airservice increasing and localization accelerating, airport construction is booming. However, in the case of an unsuitable airport site selection, it might cause a reduction in airport service and a decrease in airport demand. Thus, it is necessary to construct a representative airport and choose a suitable site selection method for economical and efficient airports in order to make the utmost use of airport functions. In this study, GSIS was used to select the airport site and applied to case study areas. GSIS could present a new method for efficient and scientific analysis in airport site selection including various factors over an extensive area. The use of both, the paired comparison method and the delphi method, could improve the objectivity of analysis results in the process considering the relative weight grade of data and priority order of analysis factors, used in airport site selection.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.813-816
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• 2010

최근 지속가능한 개발의 개념은 국제적으로 경제 개발과 환경 보전 사이에서 논쟁이 중심이 되고 있으며, 수자원 개발과 관리는 이들 논쟁에서 중요한 부분을 차지하고 있다. 이와 더불어 유역을 관리함에 있어 수자원을 이수, 치수 및 수질의 단일 문제로 인식하는 것이 아니라 통합적으로 인식하는 유역통합관리(Integrated Watershed Management, IWM)의 필요성이 대두되고 있다. 이에 본 연구는 유역통합관리에 앞서 유역의 상태 및 문제점을 파악하기 위한 방법으로 EEA (European Environment Agency)에서 개발한 추진력(Driving force)-압력(Pressure)-상태(State)-영향(Impact)-반응(Response) (DPSIR) 개념 이용하여 3개의 세부 지표인 이수지표, 치수지표, 수질지표로 구성된 하나의 통합 지수인 유역수자원평가지수를 개발하였다. 세부지표인 이수지표는 연속무강우일수, 인구밀도, 용수수요, 물재이용률 등 16개의 구성요소, 치수지표는 홍수범람위험 지역 내 거주 인구수, 홍수방어시설용량, 개수율, 100 mm 이상 강수일수 등 15개의 구성요소, 수질지표는 BOD (Biochemical Oxygen Demend) 부하량, 수질 등급, 연중 목표 수질 달성일수 등 13개의 구성요소로 이루어져있다. 이를 북한강 유역 중 북한 지역을 제외한 유역 즉, 수자원단위지도 상의 춘천댐권역(1010) ~ 청평댐권역(1015)의 6개 중권역에 적용하여 비교하였다. 세부지표의 주된 요소인 유출량의 모의를 위해 장기유출모형인 HSPF (Hydrological Simulation Program - Fortran)를 사용하였다. 모형에 입력된 유역평균강수량 자료는 1973년 ~ 2008년까지의 37년의 자료기간을 갖는 북한강유역의 5개 기상관측소 자료를 Thiessen network를 이용하여 산정하였다. 본 연구를 통해서 북한강 유역의 현재 수자원의 상태를 지수화하여 나타내고 그 결과를 비교해보았다. 이 결과는 유역 수자원의 파악하여 유역통합관리시 유역의 문제점을 파악하고 이를 수정하기 위한 의사결정 우선순위를 정하는데 사용될 수 있다.