• Journal of Electrical Engineering and Technology
• /
• 제8권3호
• /
• pp.453-463
• /
• 2013

The probabilistic nature of renewable energy, especially wind energy, increases the needs for new forms of planning and operating with electrical power. This paper presents a novel approach for determining the short-term generation schedule for optimal operations of wind energy-integrated power systems. The proposed probabilistic security-constrained optimal power flow (P-SCOPF) considers dispatch, network, and security constraints in pre- and post-contingency states. The method considers two sources of uncertainty: power demand and wind speed. The power demand is assumed to follow a normal distribution, while the correlated wind speed is modeled by the Weibull distribution. A Monte Carlo simulation is used to choose input variables of power demand and wind speed from their probability distribution functions. Then, P-SCOPF can be applied to the input variables. This approach was tested on a modified IEEE 30-bus system with two wind farms. The results show that the proposed approach provides information on power system economics, security, and environmental parameters to enable better decision-making by system operators.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2015년도 제46회 하계학술대회
• /
• pp.331-332
• /
• 2015

Since $20^{th}$ century, along with the rapid industrial advancement, the concentrated urban development in specific large cities have made people migrate to those cities, thus causing problems in the power system stability. In case of Korea, more than 40% of the power system demand comes from the consumers in Seoul Metropolitan area and the rate is expected to increase. With the continuous increase of power demand, in order to meet the demand for system reliability improvement, the power system was multi-looped for reliability enhancement, the problem of fault current happened. In this situation, there are several methods for fault current reduction likes current limiting reactor, replacing circuit breaker, splitting busses, etc. But these methods reached its limit, power system needs more fundamental solutions such as grid segmentation. In this paper, we assume grid segmentation already has been progressed using VSC BTB HVDC. Then, this paper discusses operating point of HVDC in metropolitan area considering loss minimization and handy flow control. The simulation is proceeded on 2027 KEPCO system.

• 한국경영과학회:학술대회논문집
• /
• 대한산업공학회/한국경영과학회 1991년도 춘계공동학술대회 발표논문 및 초록집; 전북대학교, 전주; 26-27 Apr. 1991
• /
• pp.357-365
• /
• 1991

Military material-supply problem is one of the most important logistic problems under conscription system. Formally, two approaches were followed lowed to this problem. (1) Needs for material per soldier is estimated by past experience. The total demand for the material is estimated by multiplication of this coefficient and the number of soldiers given in the governmental programme. (2) The total demand for the material is estimated by the forcast based on the past statistics. The material supply system based on these estimates, however, relies too much on past statistics ;lack of flexibility is feared to adapt itself to changes in conscription programme, life-time of materials and so on. In this paper, the author has followed new approach : The conscription system itself is a linear input-output system, in which sequences of enlistment and dischargement are regarded as input and output. And the sequencial demands for the material are related by another linear transformation to the former sequences. In this regard z-transformation is applied to construct to transfer functions associated with this system. With these transfer functions, methods are established to determine the material demand corresponding to conscription programme and life-time distribution. Numerical methods by computers are also prepared.

• 한국생활과학회지
• /
• 제14권6호
• /
• pp.883-898
• /
• 2005

This study was to find out the demand for the education of elder marital couples to improve their relationship. The results of this study were as follows. 1. Marital satisfaction was affected by four elements such as confidence and affinity, mutual respect, communication, and cohesion. Each element showed significant differences by the socio-demographic variables. Out of these variables, age, academic career, health, occupation, and salary showed significant difference in all 4 elements affecting the marital satisfaction. 2. The couples with shorter marriage period, with religion, and belonging to a nuclear family, and doing social activities were recognized the necessity of education highly. 3. The higher the confidence and affinity, and cohesion between couple, the higher the demand for education program. The lower the score of communication between couple, they participated more often in the educational program. For the improvement of confidence and affinity between couple, the educational program with partners is necessary.

• KIEAE Journal
• /
• 제13권2호
• /
• pp.101-106
• /
• 2013

As the number of aged people increase, hospitals specializing in elderly cares have also increased very rapidly. Therefore it is necessary to improve the quality of these hospitals for the elderly people in order to enhance the function of these hospitals not only for conventional treatment but also for recovery and convalescence. To study such trend and needs, this study researched on planning for Elderly Hospital's Atrium that provides a space for the elderly people so that they may enjoy the natural environment while being supported from diverse aspects for long term cares and sustained living, and tried to find out design solutions based on users' demand through questionnaire survey and interviews both with the management of the elderly hospital and the inpatients or the users. As a result of this study, it was revealed that each user showed his or her own respective characteristics concerning his or her expectation about the environment of their using spaces, and according to this result the strategic direction and design plan could be drawn. Based on plans for this Elderly Hospital's Atrium specializing in cares for the elderly people, useful information will be provided for caring, treatment and recovering environment of the elderly hospitals in future considering not only the conventional medical and technical services but also the inpatients' or the users' physical, psychological and social factors.

• 농촌계획
• /
• 제15권4호
• /
• pp.1-10
• /
• 2009

Rural amenity is regarded as a breakthrough that can revitalize the rural communities. The demand for rural amenity development is also increasing since the urban people have growing incomes and leisure time. This study was implemented to survey the needs and application directions of rural amenity database. The survey questionnaires were collected from various related groups including industry, universities, administration and research institute. Two kinds of analysis of variance (ANOVA) were carried out in order to prioritize the building rural amenity resource map among four user groups and ten rural amenity resources. The result of survey showed that most of respondents had been aware of amenity resources and the industry group had the highest level of utilization in making decisions for rural development. Although the significant difference among groups was not shown in the priority, the priority in the construction of information map was shown the significant difference among 10 kinds of amenity resources. Landscape's map and traditional resource map were relatively higher priority than the other resource map.

• 한국시뮬레이션학회논문지
• /
• 제15권4호
• /
• pp.153-160
• /
• 2006

국내 이동통신 서비스 시장은 급속하게 발전해왔다. 이러한 성장에 맞춰 WCDMA 서비스가 중요한 성장 동력으로 기대했으나 해외에 비해 국내 보급률은 더딘 실정이다. 하지만 HSDPA의 상용화가 이루어지면서 정체된 WCDMA 단말기의 수요를 이끌 것으로 예상된다. 따라서 신규 WCDMA 서비스의 수요를 예측하고 그에 맞는 새로운 이동통신 사업 전략을 세우는 것이 필요할 것이다. 본 논문은 이동통신 단말기의 가격과 성능에 따른 소비자의 구매 효과를 반영하고, 변형된 Lotka-Volterra 예측 모형을 개발하여 향후 WCDMA 서비스 가입자를 예측하였다.

• 농촌지도와개발
• /
• 제17권3호
• /
• pp.447-473
• /
• 2010

Japan is very similar with Korea in aspect of decreasing population of rural areas and increasing demand of urbanites' migrating to rural areas. Therefore, government ministries of Japan including Ministry of Agriculture, Forestry and Fisheries have performed policies for popularizing stay in rural area and rural in-migration as a new lifestyle since the early 2000s. The purpose of this study is to find implication for rural repopulation in Korea though reviewing Japan's policy for urban-rural interchange. In Japan, demand of urban-rural interchange was segmented by the length and purpose of stay, and the policy was made by the way of meeting the needs of each segmented group. After two cases of policy implementation in Kochi and Fukushima prefecture were studied, a few implications were discussed. For rural repopulation, comprehensive vision and strategy of urban-rural interchange including from rural tourism to rural inmigration and diverse programs for satisfying various kinds of demand of urban-rural interchange need to be developed.

• 가정간호학회지
• /
• 제24권2호
• /
• pp.151-159
• /
• 2017

Purpose: The purpose of this study was to identify nursing demands according to general characteristics and diseases of inpatients to whom comprehensive payment systems apply. Methods: This study was designed as a retrospective research study using the electronic medical records of Hospital Information Systems (HIS). Participants were 836 subjects who received seven Diagnostic-Related Group diagnoses among inpatients of one tertiary hospital from January 1, 2015 to June 30, 2015. Data were analyzed using SPSS 23.0. Results: Nursing demand among inpatients'seven Diagnostic-Related Group diagnoses was relatively higher for appendectomy, cataract surgery, and hysterectomy, while there was a significant difference depending on the age, duration of admission, admission path, hospital entry method and Diagnostic-Related Group. Conclusion: The results can be utilized as basic data on accurate nursing demands that reflect various features of patients.

• 토지주택연구
• /
• 제14권1호
• /
• pp.17-32
• /
• 2023

본 연구에서는 수요에 기반한 해외산업단지 조성을 위해 베트남과 인도네시아를 대상으로 제조업 부문 투자유치 분야와 한국기업의 해외진출 현황을 살펴보았다. 또한, 산업단지 등에 입주한 국내기업을 대상으로 설문조사를 실시하여 해외진출의향에 대한 세부사항을 분석하였다. 그리고 앞서 조사한 투자유치 분야와 해외진출 희망업종 및 기진출 업종을 상호 연계함으로써 기진출 업종과의 연계, 신규시장 개척을 위한 유치분야 진출, 국가별 특화전략 도출 등 해외산업단지 조성방안을 제시하였다. 이러한 특화전략은 중점국가를 대상으로 국내외 니즈를 반영한 해외산업단지 기업유치계획 수립 시 기초자료로 유용하게 활용될 수 있을 것이다.