• 한국통신학회논문지
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• 제33권11B호
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• pp.961-967
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• 2008

Congestion control is one of major mechanisms to avoid dropped packets. Many researchers use optimization theories to find an efficient way to reduce congestion in networks, but they do not consider robustness that may lead to unstable network utilities. This paper proposes a new methodology in order to solve a congestion control problem for wired networks by using a robust design principle. In our particular numerical example, the proposed method provides robust solutions that guarantee high and stable network utilities.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.759-761
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• 2003

This test was performed to improve the cavitation property on hydro-turbine and the optimum quantity of aeration. Vibration and noise change according to hydro-turbine load. The results of aeration tests applied to chungju hydro-turbine.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.45-47
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• 1993

Load Management, is originated from efficiency improvement of energy use, or energy conservaion. Traditionally, electric utilities have constructed new power plants to meet the steadily increasing electricity demand. Power development planning, however, is becoming more difficult in the countries like Korea, Japan, and the United States, and increasing concerns about global environmental problems necessitate changes from existing supply-side options based on fossil-fuel to environmentally agreeable supply strategies. This paper discusses the demand side management strategy with emphasis on the concept, implementation scheme, and current practices employed in utilities.

• 전기저널
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• 8호통권92호
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• pp.28-31
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• 1984

• 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.

• 한국사회복지학
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• 제61권3호
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• pp.179-204
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• 2009

본 연구는 사회복지학에서의 실행연구 이해와 적용을 높이기 위해 실행연구의 연구 설계 과정에 따라 실행연구 사례를 소개하면서, 사회복지학에서의 유용성을 논의하고자 한 것이다. 즉, '장애인거주시설에서의 이용자 참여 매뉴얼 개발 연구'의 수행 과정을 설명하고, 실행연구과정에서 연구참여자들에게 어떠한 변화가 나타나는지 질적 양적 자료 분석을 통해 실행연구의 효과를 살펴보았다. 이와 함께 실행연구의 사회복지학에의 유용성은 무엇인지를 논의하였다. 이 연구는 국내 최초로 사회복지학에서의 실행연구를 적용한 연구 수행과정 및 그 효과를 탐색함으로써, 사회복지학 실행연구의 이해 및 확산에 기여할 것으로 본다.

• 한국환경교육학회지:환경교육
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• 제10권2호
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• pp.239-248
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• 1997

This survey is related to the status of education for environmental managers, who are taking charge of pollution control untilities, and its analyses. This survey is also discussing the improvements of educational course for the trainees, who have already been educated in environmental background as well as its problems. The 45% of in-service trainees were those who had graduated more than a junior college. But under the 50% of them were those who had school careers of less than a high a high school, which means that the trainees have trouble in acquiring the professional knowledges on environmental educations such as the lectures and the practice educations. All over the country, 46 junior colleges, and 65 universities which have a environmental education program, have produced the graduates who major in the environment. Therefore, it is demanded that they should be properly treated. In this research work, it is shown that the 76% of environmental managers have no certificate of environmental study. It is thought that this has resulted from the released environmental law; the untilities of the first and second grade need a manager with a certificate related with environment, the third grade utilities only need a manager with a non-specified certificate related with environment or a manager with more than 3 years environmental practice careers, the fourth and fifth grade utilities do not need the certificate related to environment. In view of relation between environment pollutions and the management of environmental utilities, it is thought that present environmental laws should be improved to be strict. The fact that the differences in regions or utilities are not considered in the contents of texts, has reduced the efficiency of education. Therefore, it is needed that the experts and the in-service managers should take part in the development of the text. In this survey, the more than 20% of trainees have negative opinions about the result of this education, which means that overall the environmental practice education should be reconsidered. In the educational methodology, more than 50% of trainees have the opinion that they want spot speciations, the audio-visual educations and the practice. Therefore, it is demaned that the subjects, syllabus, and the allotment of time ect, should be reorganized for the more practical education.

• 한국전자통신학회논문지
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• 제15권3호
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• pp.495-502
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• 2020

본 논문에서는 자기 에너지 하베스트를 이용하여 지하 공동구의 비상조명 LED를 구동하는 전력관리 회로를 설계하였다. 자기 에너지 하베스트는 하베스터 소자와 전력관리 회로로 구성되어 진다. 제안하는 회로는 정류기, 배터리 충전회로와 LED 구동회로로 만들어졌다. 평상시에는 만들어진 전력으로 배터리를 충전하고, 비상시에는 배터리에 충전된 에너지를 이용하여 LED를 구동한다. 측정 결과, 47 mF 커패시터를 충전하는 데 2분이 걸렸다. 이것은 약 3분 30초 동안 비상조명용 LED를 구동할 수 있는 전력량이다. 이를 통해, 본 논문에서 제안하는 자기 에너지 하베스트용 전력관리 회로를 이용하여 별도의 전원을 끌어오기 어려운 지하 공동구의 비상조명 LED 구동용 전원장치로 사용할 수 있는 것을 확인하였다.

• 한국식품조리과학회지
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• 제24권3호
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• pp.325-332
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• 2008

The purpose of this study was to analyze the gap in perceived sanitaion management importance-performance for school foodservice facilities and utilities. Questionnaires were delivered to 200 dietitians who are employed in school foodservice. A total of 108 were usable, resulting in an 54.0% response rate. Statistical analyses were performed using the SAS package program(version 8.2 for Windows) for descriptive analysis, t-tests, and importance-performance analysis (IPA). Among the respondents, 58.3% of the dietitians had more than 10 years of work experience, 81.5% were university graduates, and 64.8% worked in elementary schools. Also, 89.8% of the school foodservices provided meals once a day. According to the importance and performance analysis for 25 items, significant differences were found between importance and performance and the importance score was significantly higher than the performance score for all of the items. The results of IPA showed the following areas as improvement priorities: physical separation between the clean areas and the unclean areas to prevent cross-contamination, and proper management of the temperature and humidity within kitchens and food storage facilities. Overall, the IPA results indicated that the items in need of urgent need of improvement will require political support, and above all, continued research. Finally, better models of foodservice facilities and utilities are needed to improve and modernize the operating conditions of these various foodservice establishments.

• Korean Chemical Engineering Research
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• 제46권1호
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• pp.147-155
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• 2008

대부분의 화학공장에서는 유틸리티의 운용에 따라 경제성이 크게 좌우된다. 공장에서 이용되는 유틸리티는 중앙 집중화된 유틸리티 시스템에 의해 제공되는데 유틸리티 가운데 가장 큰 비중을 차지하는 것은 수증기로서 이의 효율적인 관리는 공장의 전력 및 용수의 수급에도 직접적인 영향을 미치게 된다. 이에 따라 대학교 4학년 학생 및 회사의 신입사원들이 유틸리티의 효율적 분배에 대한 개념을 바르고 신속하게 정립하고 실제 운전에 활용할 수 있도록 하는 것이 중요하다. OOUS(optimal operation of utility system)는 빠른 시간 내에 유틸리티, 특히 수증기의 효율적 생산과 최적 배분방법들을 학생들이나 신입사원들에게 교육시킬 수 있도록 구성된 시스템이다. OOUS에서는 다양한 유틸리티 관련장치 및 공정들을 다루고 있으며 유틸리티 관련 장치 모델과 운전지식 베이스를 기반으로 최적 운전조건이 제시되도록 함으로써 전체 유틸리티 플랜트의 조업 경비가 절감될 수 있도록 하였다.