• Nuclear Engineering and Technology
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• 제36권6호
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• pp.485-496
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• 2004

Typical probabilistic safety assessment (PSA) results were used to estimate the performance indicator (PI) thresholds of unplanned reactor scram (URS) and safety system unavailability (SSU) for Korean nuclear power plants (NPPs). The changes in core damage frequency (${\Delta}$CDFs) of $10^{-6}/yr$, $10^{-5}/yr$, and $10^{-4}/yr$ were adopted as the risk criteria in setting up the PI thresholds. The PI thresholds for the URS were estimated using information pertaining to the initiating event frequencies, the CDF, and the CDF contribution of each initiating event. The PI thresholds of the SSU were estimated using information on the unavailability, the Fussell-Vesely importance, and the CDF.

• 교육시설 논문지
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• 제22권1호
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• pp.37-45
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• 2015

Over the years, great attention has been shown to the function of the campus facilities that should be well-equipped, operated and maintained to better support university's two main goals: providing education and supporting research. Properly managing campus facilities is the initial step to be prepared to meet the rapidly changing global educational standard. However, so far, no definitive answer has been given to the question of what service level/scope is appropriate for the effective campus facility management (FM) in Korea. Therefore, at the outset, it is imperative to establish the framework for the standardized campus FM services. The main focus of this research is to provide comprehensive understanding on the campus FM by establishing the framework in the form of FM performance indicator (PI). As the first step, FM standards set by Korean Agency for Technology and Standards (KATS) has been thoroughly reviewed and analyzed to establish the framework for FM standards applicable to campus facility management. Secondly, extensive literature review on the development of performance indicator (PI) for the educational facilities has been conducted to classify PI types and complement FM_KS. Finally, specific guideline and PIs developed by APPA which is globally well-known association in the field of FM for higher education facilities has been added to the combined PI which is the mixed form of FM_KS and PIs from the previous literature. This research provides campus facility managers and FM outsourcing service providers with framework in the form of PI to support future directions of effective campus FM services.

• 상하수도학회지
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• 제20권3호
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• pp.411-429
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• 2006

To improve Service quality for water and wastewater works, most water and wastewater utility effort to develop not only facility construction but also operation optimization. The operation is optimized by accurate estimation for ongoing situation. And from the accurate estimation, utility operator gain a information about their service quality and problems, So we developed a evaluation tool (Performance Indicators: PI) for service activity of water and wastewater works. The PI was developed in many countries and some international organizations (World Bank, IWA etc.) for service benchmarking. And ISO (international organization for standardization) just has been making a service standard for water and wastewater system (So called ISO/C224). This proceeding for making a service standard is ongoing now and will be launched in 2007. In our study, PI was composed of 6 parts (A human resource, facility management, operation, service quality, finance and environment). To evaluate water utilities, performance indicators for water was consisted of 100 items. Each 2 water utilities were estimated by this performance indicator. From the study, we just know that the performance indicator was a very useful tool to estimate utility service quality. And from the result, it is possible to know the strong and weak point of estimated utilities.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.752-757
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• 2001

To reduce stress concentration around the intersection between a spherical pressure vessel and a cylindrical nozzle under various load conditions using less material, the optimization for the distribution of reinforcement has researched. The ranked bidirectional evolutionary structural optimization(R-BESO) method is developed recently, which adds elements based on a rank, and the performance indicator which can estimate a fully stressed model. The R-BESO method can obtain the optimum design using less iteration number than iteration number of the BESO. In this paper, the optimized intersection shape is sought using R-BESO method for a flush and a protruding nozzle. The considered load cases are a radial compression, torque and shear force.

• 대한기계학회논문집A
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• 제25권9호
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• pp.1444-1451
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• 2001

The evolutionary structural optimization(ESO) method has been under continuous development since 1992. The bidirectional evolutionary structural optimization(BESO) method is made of additive and removal procedure. The BESO method is very useful to search the global optimum and to reduce the computational time. This paper presents the ranked bidirectional evolutionary structural optimization(R-BESO) method which adds elements based on a rank, and the performance indicator which can estimate a fully stressed model. The R-BESO method can obtain the optimum design using less iteration number than iteration number of the BESO.

• 한국산학기술학회논문지
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• 제22권3호
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• pp.707-725
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• 2021

에너지경영시스템은 생산 중심으로 발전하는 한국의 경제구조에서 에너지경영의 역할을 강조하여 지속 가능한 에너지 절약 및 온실가스 감축에 기여하고 있다. 에너지 성과에 대한 측정 방법론을 이해하는 것은 기업이 성공적인 에너지경영시스템을 구축하는 데 핵심 요소이지만, 적용 방법론, 적용 가능성 및 실제 활용도를 조사하려는 시도는 국내에서 찾아보기 어렵다. 본 연구는 에너지경영시스템에 관한 국제표준인 ISO 50006에서 제안한 4가지 에너지 성과 지표(EnPI)인 ①측정 된 에너지 값, ②측정 된 값 간의 비율, ③ 선형 회귀 모델, ④ 비선형 회귀 모델에 초점을 맞추어 에너지성과 측정에 대한 이해를 심화시키고, 효과적으로 확산시키기 위한 정책과 적정 관리 지표를 제시하는 것을 목표로 한다. 41명의 전문가들의 설문조사를 통해 수집된 데이터를 활용하여, EnPI에 대한 선호도와 산업 분류별, 조직규모, 전문가 유형별로 EnPI의 주요 선책 기준을 분석하였다. 연구 결과에 따르면 가장 선호되는 EnPI는 측정 된 값과 측정 된 에너지 값 사이의 비율이며 EnPI를 선택하는 기준은 사용 편의성이 가장 중요하다고 분석되었다.

• Journal of Korean Neurosurgical Society
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• 제39권1호
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• pp.20-25
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• 2006

Objective : The authors analyze prospectively the result of transcranial doppler[TCD] in normal pressure hydrocephalus and compared its cerebral blood flow parameters to radionuclide cerebrospinal fluid[CSF] flow study, postoperative brain computed tomography[CT] findings and clinical outcome, and studied the relationship between cerebral hemodynamics and clinical performance. Methods : Twenty five patients with hydrocephalus undertook pre- and post-operative TCD but only preoperative CSF flow study was performed. Mean flow velocity[Vm], pulsatility index[PI] and resistance index[RI] were assessed through TCD and changes in ventricle size and cortical gyral atrophy were checked through brain CT. Results : Postoperative hydrocephalus showed an increase in Vm[ACA P=0.037, MCA P=0.034], decrease in PI[ACA P=0.019, MCA P=0.017] and decrease in RI [ACA P=0.017, MCA P=0.021] compared to preoperative TCD parameters in the postoperative improvement group. In the postoperative improvement group, postoperative TCD parameters correlated with CSF flow study grade [Vm : $R^2=-0.75$, PI : $R^2=0.86$, RI : $R^2=0.78$] and ventriculocranial ratio change correlated with PI change [$R^2=0.73$]. The convexity gyral atrophy and initial TCD parameters showed close relationship to outcome. Conclusion : PI and RI can be used as an indicator of post operative prognosis, and with the addition of CSF flow study values, can also be used as a tool to predict pre-op and post-op patient status and successful shunt surgery.

• 상하수도학회지
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• 제21권4호
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• pp.453-465
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• 2007

With rapid expansion of the water market and growth of water companies, the recent trends in international water industry show that standardization of service activities concerning management of water and wastewater system (ISO/TC 224, to be issued in the second half year of 2007) is expected to have a large influence on the global water market including liberalization of water service market. In the Draft International Standard(DIS) of ISO/TC224, Performance Indicators(PIs) are suggested to estimate the service activities relating to water and wastewater treatment facilities. PIs have been developed in many countries including some international organization(World Bank, IWA and etc.) for service benchmarking. To evaluate public service level and establish plans to improve service level of wastewater utilities, we developed PIs for 120 items and applied them to 10 sewage utilities in the consideration of their scales, circumstances and conditions. In this study, we verified the applicability of the developed performance indicators(PIs). So, we concluded that PIs developed for the purpose of this study can be a useful tool applicable to objective evaluation of the service level of sewage utilities. Using the evaluation tool of PIs developed, it can also be used as a benchmarking tool in this industry as well as for enhancing the efficiency of operation and management of the sewage system. It will also contribute to the water resource management through determination of investment priorities based on the evaluation results and to raising international competitiveness of the domestic sewage utilities to meet the future opening of the water market.

• 상하수도학회지
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• 제23권6호
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• pp.871-879
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• 2009

The Korea has high population density, so the precipitation per capita is only one tenth to world average. The water resource in Korea is insufficient. But the leakage in the water distribution system is about 25%, and it is lower than other countries where water utilities are managed well. The pipelines' management also is getting worse because the leakage in the pipelines lower the ground density surrounding pipes. So, managing the leakage in the water distribution system is very important in the view of increasing the water resources and doing the efficient management of the pipeline system. Accordingly this study aimed to conduct a cause-analysis with scientific approaches considering key local factor related to water loss of distribution system and derive better performance indicators which are able to evaluate the real state of water loss management reasonably. Also this research aimed to develop a methodology capable of judging condition of infrastructure of water distribution system.

• 한국도로학회논문집
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• 제18권6호
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• pp.115-122
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• 2016

OBJECTIVES : This study develops an evaluation method, which is useful to inspect pavement condition of specific boroughs. This is because pavement condition is broadly divided into five grades via visual inspection, which does not consider the types of deteriorations, and is decided by an investigator having a subjective viewpoint. This visual inspection method is not a satisfactory method for accurate maintenance when various deteriorations occur. METHODS : The performance model considers several factors such as crack, rutting, and IRI. This method is also modified from borough SPI based on SPI (Seoul Pavement Index). Considering limited budget of borough, PI (prediction index) is suggested, which is related to the grade of pavement condition evaluation and type of materials. Practical correlation review is also conducted with statistical verification by using the Monte Carlo simulation. RESULTS : The results of the study show that modified criteria are reasonable. First, the comparison between the visual inspection result and the SPI result indicates that the R-square value is sufficiently high. Second, through the common section, each evaluation method could be compared, and the result shows considerable similarity, which increases when the range is modified. Finally, PI for predicting remaining life and the random number SPI have common parts, which means that each indicator would be adequate to be used as an evaluation method. CONCLUSIONS : Comparison and analysis results show that the developed evaluation method is reasonable for specific boroughs where financial support is inadequate for the evaluation process by using the newer equipment. Moreover, for more accurate evaluation method, previous visual inspection data should be utilized, and the database of inspection equipment have to be collected.