• 정보과학회 컴퓨팅의 실제 논문지
• /
• 제22권9호
• /
• pp.473-478
• /
• 2016

가상화 기술은 한정된 물리자원을 추상화하여 다수의 가상 자원 형태로 사용자에게 제공하는 기술로써 자원 활용률을 높이고 유동적으로 서비스를 제공할 수 있다는 장점이 있다. 하지만 한정된 물리자원을 다수의 가상머신이 공유하는 가상화 기술의 특성상, 자원 공유로 인한 성능 간섭 현상이 발생하는 문제가 있다. 이는 호스트 운영체제의 CPU 스케줄러가 가상머신에서 실행중인 프로세스의 특성을 고려하지 않고 스케줄링 하기 때문이다. 이러한 문제를 해결하기 위해 다양한 연구들이 진행되었지만 실제 근본적인 성능 간섭의 원인 분석에 대해서는 다루고 있지 않다. 본 논문에서는 KVM 기반 가상화 환경에서 가상머신의 성능 간섭의 원인을 분석하기 위해 다양한 시나리오에서의 프로파일링을 수행하고, 그 결과를 분석하여 CPU 스케줄링 관점에서 성능 간섭 현상의 원인과 그 해결 방안을 제시한다.

• 한국항공우주학회지
• /
• 제31권10호
• /
• pp.10-20
• /
• 2003

본 논문에서는 임의의 방향각을 가지고 적층된 평직 복합재료에 대하여 미세구조를 모델링하고 수치실험을 통하여 등가물성치를 계산하였다. 층간 상호이동에 의한 평직복합재료의 섬유다발의 배열의 경우의 수는 무한대에 이르므로 여기서는 몬테 카를로법을 이용하여 지정된 경우의 수에 대하여 모델링과 해석을 수행하는 전략을 채택하였다. 또한 평직복합재료의 미세구조를 효과적으로 고려하고 모델링 및 계산시간을 절감하기 위하여 수정된 분할영역 적분에 의한 단일변위장 마크로요소를 사용하였다. 계산결과, 평직복합재료 적층판의 등가물성치는 적층간에 따라서 편차가 크게 나타날 수 있음을 확인하였다. 또한 고전적층판 이론으로 계산한 값과 비교하였을 때 $0^{\circ}$, $45^{\circ}$ 이외의 적층각에서 값의 차이가 크게 났는데, 이로부터 평직복합재료 구조물의 경우 고전적층판이론으로 계산한 등가물성치를 사용할 때 주의가 필요함을 알 수 있었다.

• The Journal of Korean Physical Therapy
• /
• 제24권2호
• /
• pp.98-106
• /
• 2012

Purpose: The goal of this study was to analyze the degree of stress and methods of coping with stress in mothers of cerebral palsied children and to provide a basic resource for the development of policies to improve the mental health of mothers with cerebral palsied children. Methods: 85 mothers with cerebral palsied children and 77 mothers of normal children completed a self-administered questionnaire that evaluated the degree of stress and methods of coping with stress. Cronbach's ${\alpha}$ score was used to determine the internal consistency of the acquired data and the discriminated validity was estimated by Pearson's correlation coefficient. Independent t-tests were conducted to compare the degree of stress and method of coping with stress between mothers of cerebral palsied children and mothers of normal children and one-way ANOVA was performed to analyze the effect of generalized characteristics on stress in mothers of cerebral palsied children. Results: The degree of stress in terms of anxiety response and roles as mother for mothers with cerebral palsied children was higher than mothers with normal children. However, there was no significant difference between two group in regards to the methods of coping with stress during a stressful episode. The degree of stress for mothers with cerebral palsied children was greater when the child was younger. Conclusion: Mothers of cerebral palsied children had higher stress than that of mothers with normal children and felt more stress when their child was younger. Therefore, these results suggest that health-based policies should be developed to improve the mental health of mothers with cerebral palsied children.

• 한국축산시설환경학회지
• /
• 제19권2호
• /
• pp.177-182
• /
• 2013

We studied the possibility to produce solid fuel using cattle manure and to apply TAO (Thermophilic Aerobic Oxidation) process of solid-liquid separation fraction. The physiochemical compositions of cattle manure solid fuel chip were analyzed as water 0.12%, low calorific value 3,510 kcal/kg, ashes 11.9%, chlorine 0.82%, sulfur dust 0.5%, mercury non-detection, cadmium 1.0 mg/kg, lead 2 mg/kg, arsenic non-detection. In treating cattle manure with TAO reactor the internal temperature of the reactor was increasing higher and $50^{\circ}C$ and over was maintained after 20 hours on. The physiochemical compositions of liquids increased from pH 7.3 to pH 9.18 and EC decreased from 4.6 to 3.48 mS/cm in treating process of cattle manure with TAO reactor. COD and SCOD decreased from 16,800 to 10,400 mg/L, from 4,600 to 2,040 mg/L respectively, which showed about 38% and 56% of remove efficiency respectively.

• Journal of Preventive Medicine and Public Health
• /
• 제36권2호
• /
• pp.163-170
• /
• 2003

Objectives : This study aimed to develop an evaluation protocol of disability weights using person trade-off, and to test the reliability of the developed protocol in a Korean context. Methods : To develop the valuation protocol, the Global Burden of Disease(GBD) and the Dutch studies were replicated and modified. Sixteen indicator conditions were selected from the Korean version of disease classification, which was based on that of the GBD Study, and the person trade-off method referred to the Dutch method. Results : The disability weights were valued in a two step panel sfudy. The first step was a carefully designed group process by three panels, using person trade-off to establish the disability weights for sixteen selected indicator conditions. The second step consisted of interpolation of the remaining diseases, on a disability scale, by the individual members of three panels. The members of three panels were all medical doctors, with sufficient knowledge of the consequences of a broad variety of diseases. The internal consistency of the Korean disability weights was satisfactory. Considerable agreement existed within each panel and among the panels. Conclusions : It was feasible to use a modified evaluation protocol from those used in GBD and Dutch studies, This would provide a rational basis for an international comparative study of disability weights.

• 한국물환경학회지
• /
• 제36권1호
• /
• pp.55-68
• /
• 2020

Because of the intensified environmental problems such as climate change and resource depletion, sewage treatment technology focused on energy management has recently attracted attention. The conversion of primary sludge from the primary sedimentation tank and excessive sludge from the secondary sedimentation tank into biogas is the key to energy-positive sewage treatment. In particular, the primary sedimentation tanks recover enriched biodegradable organic matter and anaerobic digestion process produces methane from the organic wastes for energy production. Such technologies for minimizing oxygen demand are leading the innovation regarding sewage treatment plants. However, sewage treatment facilities in Korea lack core technology and operational know-how. Actually, the energy potential of sewage is higher than sewage treatment energy consumption in the sewage treatment, but current processes are not adequately efficient in energy recovery. To improve this, it is possible to apply chemically enhanced primary treatment (CEPT), high-rate activated sludge (HRAS), and anaerobic membrane bioreactor (AnMBR) to the primary sedimentation tank. To maximize the methane production of sewage treatment plants, organic wastes such as food waste and livestock manure can be digested. Additionally, mechanical pretreatment, thermal hydrolysis, and chemical pretreatment would enhance the methane conversion of organic waste. Power generation systems based on internal combustion engines are susceptible to heat source losses, requiring breakthrough energy conversion systems such as fuel cells. To realize the energy positive sewage treatment plant, primary organic matter recovery from sewage, biogas pretreatment, and co-digestion should be optimized in the energy management system based on the knowledge-based operation.

• 한국자동차공학회논문집
• /
• 제23권2호
• /
• pp.161-168
• /
• 2015

Recently, due to various environmental problems such as global warming, increases of international oil prices, exhaustion of resource, a paradigm of world automobile market is rapidly changing from conventional vehicles using internal combustion engine to eco-friendly vehicles using electric power such as EV, HEV, PHEV and FCEV. Generally, in order to measure fuel consumption and pollutant emissions of cars, chassis dynamometer tests are performed on various driving cycles before actual driving test. There are many driving cycles for performance evaluation of conventional vehicles. However, there is a lack of researches on driving cycle for EV. In this study, the urban driving cycle for performance evaluation of electric vehicles was developed. This study is composed of two parts. In the part 1, the urban driving cycle 'GUDC-EV(Gwacheon-city Urban Driving Cycle for Electric Vehicles)' was developed by using driving data, which were obtained through actual driving experiment, and statistic analysis with chronological table. In this paper part 2, in order to verify the developed driving cycle GUDC-EV, virtual EV platforms were configured and simulations were performed with actual driving data using In addition, simulation results were compared with existing driving cycles such as FTP-72, NEDC and Japan 10-15.

• 공학교육연구
• /
• 제22권6호
• /
• pp.28-39
• /
• 2019

In order to improve this, Korean universities should reorganize their curriculum such as job system research and job - based program development according to the demand of industry in order to improve their working ability due to the decrease of the school - age population and the youth unemployment rate. In this study, first, conceptualization of friendly education and definition of industry - university cooperation and analysis of cases related to friendly - educational cooperation between industry and academia, second, analysis of fusion healing majors in Healing Bio - I want to conduct research. Konkuk University Healing Bioresource College conducted a survey based on demand such as experts and industry for the development of industry - academic cooperation - friendly curriculum. As a result of this process, I developed a curriculum development committee to study the internal and external environment through the literature survey, focus group interviews, and Delphi research. The purpose of this study is to develop competitiveness curriculum reflecting competitiveness of human resource development in Korea, to develop competitiveness curriculum that reflects customized opinions of societal demand, to organize systematic curriculum to have practical ability, to strengthen the employment link through development of curriculum in accordance with the direction of human resources development, We will make contribution to build the system of operation from the center to the consumer center, evaluation of the practical ability through the curriculum and the feedback system.

• 보건행정학회지
• /
• 제16권1호
• /
• pp.17-40
• /
• 2006

With the prospect of rapidly growing health insurance expenditures, particularly spending for ambulatory care, the introduction of a case-based payment method is discussed as an alternative to the current fee-for-service based method. A system to measure case mixes of providers is a core component of such payment systems. The objective of this study were to develop a classification system for ambulatory care, Korean Ambulatory Patient Group (KAPG) based on the U.S. APG version 2.0 and to evaluate the classification accuracy of the system. A database of 64,258,386 records was constructed from insurance claims submitted to the Health Insurance Review Agency (HIRA) during three months from August 2002. A total of 41,347,307 records with a single visit was used for the development and 7% random sample of the database was used for the evaluation. Additional groups were defined to include both physician and hospital fees in the classification, age splits were added to classify the entire population as well as the population older than 65, and the definition of medical groups used by the HIRA was adopted. The variance reduction in charges achieved by KAPGs was computed to evaluate the accuracy of classification. A total of 474 KAPGs was defined compare to 290 groups in the U.S. APG. The variance reduction for charges of all visits ranged from 20% to 37% depending on the type of provider, and ranged from 22% to 42% for non-outliers, that were better than those achieved by the system currently used by the .HIRA for its internal review purpose. Although further study is required to improve the classification for complicated care in larger hospitals, the results indicated that KAPGs could be used for better management of costs for ambulatory care.

• 디지털융복합연구
• /
• 제14권6호
• /
• pp.245-251
• /
• 2016

3차원 모델링을 이용하여 연료전지의 유로형상과 유체의 흐름 방향에 따른 연료전지의 성능에의 영향성을 분석을 수행하였다. 본 연구에서 연료전지 내부의 각 유로형상과 유동장의 변화에 전류밀도와 온도의 분포가 어떻게 이루어져 있는지를 분석하였고, 연료전지 단위셀의 전체적인 성능을 분석하였다. 3차원 모델링을 수행하기 위하여 Navier-Stokes 방정식을 전산유체역학을 이용하여 풀었다. 전산유체역학에 전기화학반응의 모델을 융합하여 계산을 수행하였다. 또한, 본 연구에서는 직선유로와 실제 사용되는 형태인 직사각형 모양의 유로형태를 모사하여 유로구조의 영향성을 분석하였다. 그리고 유체의 유동장을 변형시켜 그 영향성과 결과를 비교해 보았다. 본 전산모사 연구를 통하여 연료가 풍부한 부분보다는 산소가 풍부한 부분에서 전류밀도가 보다 높은 것을 확인할 수 있었다. 또한 전반적으로 전류밀도가 높은 곳에서 온도가 높은 것으로 확인할 수 있었다. 본 연구를 통하여 온도의 분포와 유로형상과 유동장 그리고 전류밀도의 연관성을 확인할 수 있었다.