• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2007년도 춘계학술대회
• /
• pp.639-643
• /
• 2007

Tidal regime change with general hydrolic condition change is examined, according to Garolim Tidal Power Plant (TPP) operation. Numerical model has been developed for the Yellow and East China Seas region, in order to consider the tidal regime change by the TPP operation. The changes of tidal elevation and tidal current inside the Garolim bay are also investigated in details, along with examining the change of the tidal flat area with operation. The field measurement for the tide and current have been carried out for the validation of the numerical model and for understanding the state of current system in the present state.

• 신재생에너지
• /
• 제3권2호
• /
• pp.3-10
• /
• 2007

Tidal regime change with general hydrolic condition change is examined, according to Garolim Tidal Power Plant (TPP) operation. Numerical model has been developed for the Yellow and East China Seas region, in order to consider the tidal regime change by the TPP operation. The changes of tidal elevation and tidal current inside the Garolim bay are also investigated in details, along with examining the change of the tidal flat area with operation. The field measurement for the tide and current have been carried out for the validation of the numerical model and for understanding the state of current system in the present state.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 추계학술대회 논문집 전력기술부문
• /
• pp.153-156
• /
• 2001

The transformer and the OF cable are cooled and insulated by insulating oils in their body. The insulating oil expands or contracts with the heat transfer according to the operating conditions of the electric facilities. So we install the $N_2$ gas tank connected with the insulating oil system to overcome the change. The change of the insulating oil volume for the operation temperature range must be calculated to decide the $N_2$ gas volume and to set the alarm point for safe operation. It is known that this change is proportional to the temperature change and to the insulating oil volume if the temperature change is small enough.[1][11] However this proportional formula has been accepted generally in the design of electric facilities for wide operation temperature range such as $40^{\circ}C{\sim}125^{\circ}C$. Hence, it makes large errors in calculation which car result in serious damage against safe operation of the electric facilities. This paper presents a improved method of calculating the accurate change of the insulating oil volume to insure the safe operation of electric facilities.

• 한국농공학회논문집
• /
• 제47권6호
• /
• pp.15-24
• /
• 2005

The normalization on the characteristics of water level change at the upstream gauging station was attempted according to the operation of drainage sluice gate of the Geumgang estuary dam. The characteristics were normalized by the analysis of water level change and by the linear-regression of the water level data measured at the inner station of Geumgang estuary dam and upstream gauging station. The results of normalization may be referred to the management of Geumgang estuary lake, the operation of pumping and drainage stations in the shore of the lake. The mean response time of water level change on Ibpo, Ganggyeong and Gyuam water level station were 39,81 and 160 minutes, when sluice gate was opened respectively. The mean velocity of surface wave, the mean displacement of water level change, the mean time of water level change and the mean rate of water level change varied largely depending on the location of gauging station and the characteristics of stream section of the water level gauging station.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2015년도 학술발표회
• /
• pp.232-232
• /
• 2015

Land use and climate changes are the important factors to determine the runoff and sediment loads from the watershed. The changes also affected to runoff volume/pattern to the dam operation and may cause flood and drought situations in the downstream area. Sirikit Dam is one of the biggest dams in Thailand which cover about 25 % of the runoff into the Central Plain where the Bangkok Capital is located. The study aims to determine the effect of land use change to the runoff/sediment volume pattern and the rainfall-runoff-sediment relationship in the different land use type. Field measurements of the actual rainfall, runoff and sediment in the selected four sub-basins with different type of land use in the Upper Nan Basin were conducted and the runoff ratio coefficients and sediment yield were estimated for each sub-basin. The effect of the land use change (deforestation) towards runoff/sediment will be investigated. The study of the climate change impact on the runoff in the future scenarios was conducted to project the change of runoff volume/pattern into the Sirikit Dam. The improvement of the Sirikit Dam operation rule was conducted to reduce the weakness of the existing operation rules after Floods 2011. The newly proposed dam operation rule improvement will then be evaluated from the water shortage situations in the downstream of Sirikit Dam under various conditions of changes of both land use and climate when compared with the situations based on the existing reservoir operation rules.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
• /
• pp.2286-2291
• /
• 2011

Technology on the rolling stock is very composition and system engineering. We have to consider to many parameters on the rolling stock design. High speed train is interface between rolling stock and infra system of rail, signal, communication etc. For many years testing operation has experienced substantial growth based on various advanced new technology. Recently some problems was clearly stated on effective management, practical use and testing operation of the the rolling stock on the technology change. This paper presents some results of the study on necessary requirements of the operation testing for rolling stock technology change. We propose a general plan to suggest the operation testing and the parameters of the rolling stock on the technology change in the text.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 1999년도 추계학술대회논문집
• /
• pp.123-130
• /
• 1999

The bus as a feeder trip should supply equality service to the whole community. But in spite of the change of latent demand to the bus by the variety of regional structural change, the existing bus route can not supply effective feeder service. For cope with the latent demand to the bus, this study establish a concept that frame of the bus operation and management. This study tackled to evidence this fact by analyzing the bus transport problems in terms of the urban growth, and following issues were discussed: 1) the strategy for improvement of bus operation, 2) the land use control which is appropriate for the public transport network, 3) the economical range to justify the bus operation, 4) the allowance for the private transport mode. On the second part of this study, the difference on the bus operation was compared to determine the range within which the bus operation can be justified. This would provide the direction to improve the management for bus operation and fundamental information to develop the bus operation system.

• 한국정보통신학회논문지
• /
• 제8권6호
• /
• pp.1257-1265
• /
• 2004

온톨리지는 시맨틱 웹의 핵심 요소이며 시간이 흐름에 따라서 변화하는 특징을 가지고 있다. 온톨리지에서 발생하는 변화는 도메인 변화, 개념 변화, 메타데이터 변화 등이 있다. 이 논문에서는 이들 변화와 시간차원을 기반으로 하는 변경 집합을 제안한다. 온톨리지 버전은 대량의 정보를 저장하고 관리해야 하는데 이를 위해서 변경 집합을 이용한 버전 저장 방법들 제안한다. 제안하는 방법들 사이에 성능을 비교하고 평가한다.

• 대한영양사협회학술지
• /
• 제6권1호
• /
• pp.33-43
• /
• 2000

Environmental pressures from such sources an economic condition, the government and inter-institutional competition create managerial challenges. Economic pressures may be forcing dietetic dept, in hospital to utilize cost∙benefit analysis to assist them in their problem solving. Cost∙benefit analysis have been widely used in business, industry and many other fields with only limited application to foodservice. Due to the lack or this information the purposes of this study were to identify use of cost∙benefit analysis in hospital foodservice system to evaluate the economic efficiency of alternatives, and to make recommendation for operation system change. Using the cost∙benefit method, cash flows are separated into cost and benefits. For an alternative to be selected, indicators, such as NPV, benefit-cost ratio (B/C ratio) with 5% discount rate per annum. The sensitivity analysis was also conducted with difference rate 3%, 7% respectively and reduced employee payroll change. The result of this study can be summarized as follows : 1. The total cost of investment for operation system change was 390,570 thousand won and the total benefit through operation system change was 865,808 thousand won. 2. Net present value(NPV) for 5 years was 475,239 thousand won and benefit-cost ratio was 2.22. 3. In sensitivity analysis with different discount rate 3%, 7%, benefit-cost ratio was 2.25, 2.18 respectively, with total reduced employee payroll change, benefit-cost ratio was 2.86. In conclusion, total benefits were exceeded total costs. Therefore, the project of operation system change in hospital foodservice was found to be economically efficient.

• 한국습지학회지
• /
• 제21권spc호
• /
• pp.9-15
• /
• 2019

기후변화에 따른 강우패턴의 변화로 인해 가뭄의 발생주기가 짧아지고 있으며 다목적댐의 운영 또한 변화하고 있다. 다목적댐의 물 부족을 사전에 방지하고 안정적인 용수공급을 위한 운영에 대한 중요성은 증가하고 있는 실정이다. 본 연구에서는 현재 다목적댐에 적용중인 운영기준을 기반으로 기후변화 시나리오가 반영된 운영기준을 개발하고 평가하였다. 기후변화가 반영된 기준저수량은 기존대비 평균적으로 34% 증가하는 것으로 분석되었으며, 기존 기준과의 평가결과 기후변화 반영 다목적댐 운영기준을 적용할 경우 용수공급에 어려움이 없을 것으로 분석되었다. 본 연구 결과는 향후 기후변화를 반영한 다목적댐의 기준수립에 도움이 될 것으로 기대한다.