• 전기학회논문지P
• /
• 제61권4호
• /
• pp.180-185
• /
• 2012

Tidal power is one of new and renewable energy sources. The seawater is stored inside a tidal embankment built at the mouth of a river or bay, where tides ebb and flow. The water turbine-generators produce power by exploiting the gap in the water level between the water outside and inside the embankment. Tidal power plant is a large plant that is installed on the sea. And then, the facility's operations and a separate control system for monitoring and maintenance is required. However, this plant predictive control of building systems and technologies have been avoided the transfer of technology from advanced global companies. Accordingly, the control system for core technology development and localization is urgently needed. This paper presents modeling and simulation using by PSS/E about generator, governor, exciter, and power system stabilizer for control system in Sihwa tidal power plant to improve the efficiency and develope of core technology. And the dynamic characteristics of governor and exciter were analyzed.

• 한국건축시공학회지
• /
• 제9권2호
• /
• pp.69-76
• /
• 2009

Recently, the twenty-first century is called "the age of localization and regionalization" in Korea. So, local government should need to keep balance between the existing administrative management and new management strategies based on CEO's mind in order to deal with the situation of such that(the age of localization and regionalization) and improve efficiency of public service. In addition, they build public buildings after that they should operate and maintain them regularly. However, Korea local governments have tried to run many projects to expand insufficient local finance that was only for profit oriented public projects without considering management. Therefore, this paper is a basic study to establish and suggest the reasonable operation plan for local government by examining and reviewing actual operation condition in the public buildings. With the evaluation method which is demanded from public construction management to introduce a civil management technique manages an investment mind standard and management basis of assessment, proposes 8 sides of financial affairs, real estate maintenance and facility management, achievement evaluation, environmental safe crisis management, judiciary and explanation responsibility with base.

• 설비공학논문집
• /
• 제5권3호
• /
• pp.226-233
• /
• 1993

Thermosyphons are simple devices that can passively transport thermal energy over relatively large distance with little temperature degradation. Especially, the thermosyphon system requires no costly energy input and is completely maintenance free. These attributes permit the use of low grade thermal energy for thermal control of structures including the stabilization of highway foundations. This paper presents the experimental results of the snow melting system in which thermosyphon was utilized to ransfer the earth energy to the pavement to remove snow and ice. The test facility, three earth heated and one unheated test panels, is designed to investigate the variables associated with removing snow and ice from pavement surfaces. The results of these test show that the earth heated panel surface temperature is higher $2{\sim}6^{\circ}C$ than unheated panel when the ambient air temperature is $-7^{\circ}C$. The thermal performance of this earth source thermosyphon system for road heating showed that there was no snow on the heated test panels when the snowfall was 5cm average for the region.

• 대한안전경영과학회지
• /
• 제8권3호
• /
• pp.77-86
• /
• 2006

After conducting an investigation of a specific workplace, 372 labor workers, who are employed at a certain domestic petrochemical company valve operating and maintenance processing section, were personally questioned about specific work-related ailments. According to the results, 57% of workers who were working in the petrochemical industry have suffered from pain-related musculoskeletal disorders in, at least, more than 1 body part. Specifically, there are more than 28% of workers suffering from pain in more than two body parts. Among the total work population, 18.8 % of workers are assumed to have a high probability of being diagnosed with musculoskeletal disorder. Also, according to the RULA checklist which evaluates environmental improvement conditions of the workplace, 76.7% of workplaces among the inspected areas have high hazardous work factors that are related to musculoskeletal disorder and needs to be improved upon and observed right away or in the foreseeable future. The prior factor has a high correlation and pain rate which is due to an improper work posture. Originally, this improper work posture is caused mostly by ergonomically incorrect facility design. Furthermore, the structure of the workplace does not consider the worker's individual build.

• 대한안전경영과학회지
• /
• 제14권1호
• /
• pp.225-233
• /
• 2012

The research discusses interrelationship of structural and reliability importance measures which used in the probabilistic safety assessment. The most frequently used component importance measures, such as Birnbaum's Importance (BI), Risk Reduction (RR), Risk Reduction Worth (RRW), RA (Risk Achievement), Risk Achievement Worth (RAW), Fussel Vesely (FV) and Critically Importance (CI) can be derived from two structure importance measures that are developed based on the size and the number of Minimal Path Set (MPS) and Minimal Cut Set (MCS). In order to show an effectiveness of importance measures which is developed in this paper, the three representative functional structures, such as series-parallel, k out of n and bridge are used to compare with Birnbaum's Importance measure. In addition, the study presents the implementation examples of Total Productive Maintenance (TPM) metrics and alternating renewal process models with exponential distribution to calculate the availability and unavailability of component facility for improving system performances. System state structure functions in terms of component states can be converted into the system availability (unavailability) functions by substituting the component reliabilities (unavailabilities) for the component states. The applicable examples are presented in order to help the understanding of practitioners.

• 한국태양에너지학회 논문집
• /
• 제22권4호
• /
• pp.97-106
• /
• 2002

The purpose of this study is to analyze the life cycle cost of primary cooling system by systematic support cost. Life Cycle Cost(LCC) is the process of making an economic assessment of an item, area, system, or facility by considering all significant costs of ownership over an economic life, expressed in terms of equivalent costs. The essence of life cycle costing is the analysis of equivalent costs of various alternative proposals. In order to select economical primary cooling system in early heat source plan stages, the research investigates cost items and cost characteristics during project process phases such as planning/design, construction, maintenance /management, and demolition/sell phases. The study also analyze the life cycle cost by capacity leading to suggest the most economical primary cooling system by systematic support cost.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
• /
• 제14권4호
• /
• pp.39-46
• /
• 2008

Construction and operation of Germ Free Pigs' facilities are very expensive because pigs' rooms and other major rooms of the facility require germfree environments. Especially, running the HVAC system of aseptic facilities requires a lot of expenses. However, proper location and efficient shape of outlets/inlets for the ventilation of the room can reduce the excessive running cost. In order to do that, this study proposes alternative location and shape of ventilation outlets/inlets to the existing design pattern in germfree pigs' room. The design condition of this study is the maintenance of adequate temperature(24$^{\circ}C$, $NH_3$concentration level(below 1.5 ppm), and air stream speed(below .25m/sec) in the pigs' room for the summer and the winter together. As the Software Program, FLUENT(Ver. 6.2) has been used for the analysis of proposed ventilation patterns. In conclusion, wall inlets and ceiling inlet/outlet are advisable in summer, wall inlets and ceiling outlets is advisable in winter. As far as the shape is concerned, diffuser type for the ceiling outlet is desirable.

• 정보화연구
• /
• 제9권1호
• /
• pp.67-78
• /
• 2012

현대의 조직들은 각 부서별로 응용프로그램 서버, 웹 서버, 데이터베이스 서버, 메일 서버 등과 같은 수많은 서버들을 보유하고 있다. 이로 인한 서버 과다보유는 이제 공공기관과 사기업을 막론하고 정보시스템 센터에서는 일반화된 현상이다. 서버 과다보유는 단일 응용프로그램만을 지원하는 전용서버의 도입이 주요 원인이며, 이로 인해 낮은 자원 활용률, 대규모 공간 사용, 높은 관리비용 등과 같은 문제가 발생하는데, 하드웨어, 소프트웨어, 유지보수비용, 설비, 인건비 등의 절감을 통해 이러한 문제를 해결해 줄 수 있는 서버통합이 그 해결책이다. 본 연구에서는 재난관리시스템의 사례연구를 통해 공공기관의 서버통합 기법을 제안하였다.

• 한국정보통신학회논문지
• /
• 제19권11호
• /
• pp.2731-2738
• /
• 2015

막대한 인명과 재산피해를 발생시키는 홍수재해를 사전 예측하고 예방하기 위한 재해 관측설비 및 시스템의 중요성이 전 세계적으로 부각되고 있는 추세이다. 본 논문에서는 수문관측설비에 대한 장비성능, 호환성, 적용성, 신뢰성 등의 안정성 검증 및 S/W, 백신 등 신규 프로그램 적용 안정화 시험 등을 목적으로 수문관측 성능시험센터를 구축하였으며, 이를 통하여 시험항목, 시험절차서, 시험 기준값의 정립 등 성능시험 표준가이드라인을 개발하여 설비의 표준검증체계를 구축하고자 하였다. 또한 설비의 특성 분석 및 유지보수 이력관리, 성능시험 데이터에 대한 데이터베이스화, 시험 후의 성적서를 발행할 수 있도록 프로그램을 개발하였으며, 이를 통하여 수문관측설비에 대한 과학적인 관리 및 운영의 효율성을 높이고자 하였다.

• 설비공학논문집
• /
• 제18권10호
• /
• pp.791-799
• /
• 2006

The fault diagnosis technologies may be applied in order to decrease the energy consumption and the maintenance cost of an air-conditioning system. In this paper, a fault diagnosis algorithm was developed by using a neural no-fault model and a dual fuzzy logic. Five different faults, such as the compressor valve leakage, the liquid line blockage, the condenser fouling, the evaporator fouling, and the refrigerant leakage of an air-conditioning system, were considered. The fault diagnosis algorithm was tested by using a fault simulation facility. Test results showed that the algorithm developed for this study was effective to detect and diagnose various faults. Therefore, this algorithm may be practically used for the fault diagnosis of an air-conditioning system.