• 가정과삶의질연구
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• 제15권1호
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• pp.173-190
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• 1997

The purpose of this study is to investigate social relationship and housework implementing of the elderly households in Chungbuk and to provide suggestion s from the perspective for the well-being of the elderly. The data of this study are collected through questionaire and the data of 244 respodents are analyzed using Frequency Contingency analysis one-way ANOVA. The results are as follows: firstly most elderly tend to have a close relationship with their neighbors in their houses. The activity of social relationship is routine behavior and the satisfaction of social relationship with their neighbors is high, The older the age the lower the education level and the poorer in physical health the more frequently they meet their neighbors and friends the more frequently they go to establishments for elderly and tend to play games such as a flower cards game. Secondly the average time implementing housework by elderly women is about 3.63 hours. The attitude toward housework is a l ttle negative. The average housework eqipments owned by them are 4.8 The older the poorer in physical health the lower level of owning housework equipments the shorter is the time implementing housework and the more negative is the attitude toward housework.

• 전기학회논문지
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• 제58권12호
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• pp.2335-2341
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• 2009

High technique growth of modem times and high industrial facility in consequence of buildings demand for electric power of an extensive scale with stability supply and maintenance of high quality. But, power system always have risk of network contingency. When power system break out disturbance, it circumstantially happen like uncontrolled loss of load developing from of cascading. Severely which would be raised wide area blackout, plan to prevent, which make stability through a little of load shedding and multi-level UnderVoltageLoadShdding should work. This paper presents target, sensitivity of bus voltage have choose appropriating load shedding location and load shedding decision making logic with considering rate of change of voltage have studied multi-level under voltage load shedding scheme. Calculation of rate of change of voltage applied method of least square. As a result, we are studied an dynamic analysis of 2008 summer peak data. We have been known that network analysis is a little development and developing UnderVoltageLoadShedding scheme.

• 산업공학
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• 제19권2호
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• pp.106-116
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• 2006

In this study, the priority of risk factors in supplying water through water supply pipeline network was evaluated by PROMETHEE and ANP multi-criteria decision analysis. We chose 'corrosion', 'burst' and 'water pollution' in pipe as major reference criteria and selected eight risk factors to evaluate the priority, and then we compared the results of PROMETHEE with those of ANP. We also analyzed the results of the sensitivity analysis by changing the weights and parameters of preference functions in PROMETHEE. We investigated the possibility of integrating two methods by using the results of ANP as the weights of preference function in PROMETHEE. The priority of risk factors for supplying municipal water which is evaluated by this study may provide basic data to establish a contingency plan for accidents, or to establish the specific emergency response procedures.

• Journal of Information Technology Applications and Management
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• 제24권3호
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• pp.73-92
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• 2017

Usability is one of the most important concepts regarding software quality. It can be interpreted as the goodness associated with using the software product. This paper distinguishes the goodness of an individual using experience and the goodness of a product for using. This paper proposes a software quality view model which classifies software quality views into two broad categories of end view and means view. End view includes long-term view and short-term view which is classified further into performer's view on software activity and third party's view on software activity. Means view includes intrinsic view and contingency view. The analysis of ISO 25000 Series SQuaRE demonstrates the necessity to decompose product quality model and quality in use model into five models corresponding to the software quality views respectively. The analysis on playability shows that the universal definition of usability may be an illusion. The results provide the theoretical basis to build a comprehensive and consistent body of knowledge regarding software quality, which is consisted with the set of quality models and the theories explaining the relationships among the elements of the models.

• The Journal of Asian Finance, Economics and Business
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• 제6권1호
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• pp.91-105
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• 2019

The paper aims to combine balance sheet analysis at the firm level with the International Monetary Fund's public debt sustainability assessment framework to assess state-owned enterprises' (SOE) leverage as a contingent liability to the public sector. Based on company data and the interest coverage ratio as a measure of debt at risk, aggregate baseline scenarios are projected to gauge the magnitude of SOE debt as a contingency. SOE's financial and debt ratios are first bootstrapped to generate firm-level distributions and then averaged into a fan chart of the economy-wide SOE contingent liability. Applied to the People's Republic of China as an example, the study finds that by the end of 2015 SOE leverage had grown to a substantial liability. However arbitrary the assumptions underlying these projections, it would appear that even if authorities had to mop up as much as 20% of SOE debt at risk gone bad, this would have been manageable at roughly 2.7% of the gross domestic product in 2016 or 5.5% by 2021. This projection framework is fully amenable to alternative assumptions and settings, which makes it a useful analytical tool to monitor contingent liabilities from non-financial corporate debt that have been building in emerging and advanced economies alike.

• Nuclear Engineering and Technology
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• 제52권5호
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• pp.1051-1065
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• 2020

Safety analysis of nuclear power plant (NPP) especially in accident conditions is a basic and necessary issue for applications and commercialization of reactors. Many previous researches and development works have been conducted. However, most achievements focused on the safety reliability of primary pressure system vessels. Few literatures studied the structural safety of huge concrete structures surrounding primary pressure system, especially for the fourth generation NPP which allows existing of through cracks. In this paper, structural safety reliability of concrete structures of HTR-PM in accidental double-ended break of hot gas ducts was studied by Exceedance Probability Method. It was calculated by Monte Carlo approaches applying numerical simulations by Abaqus. Damage parameters were proposed and used to define the property of concrete, which can perfectly describe the crack state of concrete structures. Calculation results indicated that functional failure determined by deterministic safety analysis was decided by the crack resistance capability of containment buildings, whereas the bearing capacity of concrete structures possess a high safety margin. The failure probability of concrete structures during an accident of double-ended break of hot gas ducts will be 31.18%. Adding the consideration the contingency occurrence probability of the accident, probability of functional failure is sufficiently low.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전력기술부문
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• pp.46-48
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• 2005

This paper discusses a probabilistic method for power system security assessment. The security analysis relates to the ability of the electric power systems to survive sudden disturbances such as electric short circuits or unanticipated loss of system elements. It consists of both steady state and dynamic security analyses, which are not two separate issues but should be considered together. In steady state security analysis including voltage security analysis, the analysis checks that the system is operated within security limits by OPF (optimal power flow) after the transition to a new operating point. Until now, many utilities have difficulty in including dynamic aspects due to computational capabilities. On the other hand. dynamic security analysis is required to ensure that the transition may lead to an acceptable operating condition. Transient stability, which is the ability of power systems to maintain synchronism when subjected to a large disturbance. is a principal component in dynamic security analysis. Usually any loss of synchronism may cause additional outages and make the present steady state analysis of the post-contingency condition inadequate for unstable cases. This is the reason for the need of dynamic studies in power systems. Probabilistic criterion can be used to recognize the probabilistic nature of system components while considering system security. In this approach. we do not have to assign any predetermined margin of safety. A comprehensive conceptual framework for probabilistic static and dynamic assessment is presented in this paper. The simulation results of the Western System Coordinating Council (WSCC) system compare an analytical method with Monte-Carlo simulation (MCS).

• Journal of Astronomy and Space Sciences
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• 제33권4호
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• pp.323-333
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• 2016

In this study, the uncertainty requirements for orbit, attitude, and burn performance were estimated and analyzed for the execution of the $1^{st}$ lunar orbit insertion (LOI) maneuver of the Korea Pathfinder Lunar Orbiter (KPLO) mission. During the early design phase of the system, associate analysis is an essential design factor as the $1^{st}$ LOI maneuver is the largest burn that utilizes the onboard propulsion system; the success of the lunar capture is directly affected by the performance achieved. For the analysis, the spacecraft is assumed to have already approached the periselene with a hyperbolic arrival trajectory around the moon. In addition, diverse arrival conditions and mission constraints were considered, such as varying periselene approach velocity, altitude, and orbital period of the capture orbit after execution of the $1^{st}$ LOI maneuver. The current analysis assumed an impulsive LOI maneuver, and two-body equations of motion were adapted to simplify the problem for a preliminary analysis. Monte Carlo simulations were performed for the statistical analysis to analyze diverse uncertainties that might arise at the moment when the maneuver is executed. As a result, three major requirements were analyzed and estimated for the early design phase. First, the minimum requirements were estimated for the burn performance to be captured around the moon. Second, the requirements for orbit, attitude, and maneuver burn performances were simultaneously estimated and analyzed to maintain the $1^{st}$ elliptical orbit achieved around the moon within the specified orbital period. Finally, the dispersion requirements on the B-plane aiming at target points to meet the target insertion goal were analyzed and can be utilized as reference target guidelines for a mid-course correction (MCC) maneuver during the transfer. More detailed system requirements for the KPLO mission, particularly for the spacecraft bus itself and for the flight dynamics subsystem at the ground control center, are expected to be prepared and established based on the current results, including a contingency trajectory design plan.

• Asian Pacific Journal of Cancer Prevention
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• 제16권6호
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• pp.2361-2368
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• 2015

Objective: To evaluate the diagnostic accuracy of contrast-enhanced ultrasonography (CEUS) in differentiating between benign and malignant enlarged lymph nodes using meta-analysis. Materials and Methods: Pubmed, Embase, SCI and Cochrane databases were searched for studies (up to September 1, 2014) reporting the diagnostic performance of CEUS in discriminating between benign and malignant lymph nodes. Inclusion criteria were: prospective study; histopathology as the reference standard; and sufficient data to construct $2{\times}2$ contingency tables. Methodological quality was assessed using Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). Patient clinical characteristics, sensitivity and specificity were extracted. The summary receiver operating characteristic curve was used to examine the accuracy of CEUS. A meta-analysis was performed to evaluate the clinical utility in identification of benign and malignant lymph nodes. Sensitivity analysis was performed after omitting outliers identified in a bivariate boxplot and publication bias was assessed with Egger testing. Results: The pooled sensitivity, specificity and AUROC were 0.92 (95%CI, 0.85-0.96), 0.91 (95%CI, 0.82-0.95) and 0.97 (95%CI, 0.95-0.98), respectively. After omitting 3 outlier studies, heterogeneity decreased. Sensitivity analysis demonstrated no disproportionate influences of individual studies. Publication bias was not significant. Conclusions: CEUS is a promising diagnostic modality in differentiating between benign and malignant lymph nodes and can potentially reduce unnecessary fine-needle aspiration biopsies of benign nodes.

• 한국건설관리학회논문집
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• 제2권2호
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• pp.98-108
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• 2001

본 연구에서는 프로젝트의 성공적 이행을 보장하기 위하여 리스크분석모델을 제안하였다. 리스크분석 모델은 CRAS라 칭하였으며, 시공자가 RBS를 통해서 리스크를 체계적으로 확인하고 분석하고 관리하는데 도움을 줄 수 있도록 설계되었다. 제안된 CRAS모델은 크게 3단계의 분석과정으로 이루어진다. 첫 단계는 시공자가 프로젝트와 관련된 리스크를 확인하고 분석해서 입찰여부를 판단하는 것이다. 두 번째 단계는 영향도, 의사결정나무, Monte Carlo 시뮬레이션을 이용하여 리스크를 정량적으로 평가하여 예비비를 산정하는 것이며, 세 번째 단계는 확률 노드, 확률 칼렌다 등의 일정관리기법과 시뮬레이션을 통해 공사일정상의 리스크를 파악하여 프로젝트의 성공여부를 판단하는 것이다. 결과적으로 본 모델은 시공자로 하여금 프로젝트에 내재된 리스크가 프로젝트의 공기와 공사비에 미치는 영향을 정량적으로 평가할 수 있도록 함으로서 시공자가 이들 리스크를 제거하는데 필요한 여러 대안을 고려할 수 있도록 하였다.