• Journal of Korean Society of Water and Wastewater
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• v.11 no.1
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• pp.109-118
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• 1997

In this study, we examined the structural analysis of water demand fluctuation for water distribution control of water supply network. In order to analyze for the length of stationary time series, we calculate autocorrelation coefficient of each case equally divided data size. As a result, it was found that, with the data size of around three months, any case could be used as stationary time series. we analyze cross-correlation coefficient between the daily water consumption's data and primary influence factors. As a result, we have decided to use weather conditions and maximum temperature as natural primary factors and holidays as a social factor. Applying the multiple ARIMA model, we obtains an effective model to describe the daily water demand prediction. From the forecasting result, even though we forecast water distribution quantity of the following year, estimated values well express the flctuations of measurements. Thus, the suitability of the model for practical use can be confirmed. When this model is used for practical water distribution control, water distribution quantity for the following day should be found by inputting maximum temperature and weather conditions obtained from weather forecast, and water purification plants and service reservoirs should be operated based on this information while operation of pumps and valves should be set up. Consequently, we will be able to devise a rational water management system.

• Korean Journal of Occupational Health Nursing
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• v.21 no.3
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• pp.229-238
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• 2012

Purpose: The purpose of this study was to measure the fatigue of operating room nurses and examine factors contributing to their fatigue. Methods: The subjects of this study were 115 nurses who worked in operating rooms of three hospitals. Data were collected from September 15, 2009 to September 30, 2009. Fatigue and job stress were measured by using the Symptom's Fatigue Scale and the job stress measurement tools in operating room nurses. Results: The mean score of fatigue level was $3.10{\pm}0.61$. We analyzed fatigue according to characteristics of subjects and found that there were significant differences in marital status, number of children and sleeping hours in general characteristics. Career, daily participation hours in the surgery relating to job related characteristics. Significant positive correlations were found between job stress and fatigue(r=.233, p= .012). Three significant variables influencing fatigue of operation rooms nurses were job stress, daily participation hours in the surgery, and sleeping hours (Adj. $R^2$=0.284, F=4.773, p<.001). Conclusion: An integrative care program that takes job stress, daily participation hours in the surgery and sleeping hours into consideration is essential to reduce fatigue in operating room nurses.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.4
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• pp.717-725
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• 2011

In the power system with an electric storage system that can increase utilization rate of the source of such new renewable energy, this paper introduces the approach on the daily unit commitment scheduling that determines simultaneously optimum operational condition and output of thermal generators and electric storage device. The unit commitment is one of the most important issues in economic operation and security of short-term operational plan of the power system. It is to determine on/off status of generator to minimize operational cost during the given period. The committed generator should satisfy various operational limitation such as estimated demand by system, spinning reserve condition within minimum operational cost. In order to determine on/off or charge/discharge/idle condition and output level of units and electric storage system, the MILP(Mixed Integer Linear Programming) is suggested. The proposed approach is the mixed method between LP(Linear Programming) and IP(integer programming) which seeks the value of real number and integer that maximize or minimize function objective within given condition. The daily unit commitment problem with the electric storage system is applied to MILP algorithm through linearization and formulation process. The proposed approach is applied to the test system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.12
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• pp.2215-2220
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• 2011

The accurate short-term load forecasting is essential for the efficient power system operation and the system marginal price decision of the electricity market. So far, errors of load forecasting for Chuseok Holiday are very big compared with forecasting errors for the other special days. In order to improve the accuracy of load forecasting for Chuseok Holiday, selection of input data, the daily normalized load patterns and load forecasting model are investigated. The efficient data selection and daily normalized load pattern based on fuzzy linear regression model is proposed. The proposed load forecasting method for Chuseok Holiday is tested in recent 5 years from 2006 to 2010, and improved the accuracy of the load forecasting compared with the former research.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.507-510
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• 2003

The development of a basin-wide runoff analysis model is to analysis monthly and daily hydrologic runoff components including surface runoff, subsurface runoff, return flow, etc. at key operation station in the targeted basin. A short-term water demand forecasting technology will be developed taking into account the patterns of municipal, industrial and agricultural water uses. For the development and utilization of runoff analysis model, relevant basin information including historical precipitation and river water stage data, geophysical basin characteristics, and water intake and consumptions needs to be collected and stored into the hydrologic database of Integrated Real-time Water Information System. The well-known SSARR model was selected for the basis of continuous daily runoff model for forecasting short and long-term natural flows.

• Journal of the Korean Solar Energy Society
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• v.29 no.5
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• pp.1-7
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• 2009

Energy demands for offices in Korea are surveyed and analyzed to generate communicational models for simulations. Daily energy loads of 13 office buildings scattered in the 6 largest cities in the country are surveyed and analyzed based on energy consumption log sheets. Detailed hourly loads that are frequently required when a detailed operation simulation is performed are measured using remote data acquisition processes for 3 offices. The complete load demand models of electricity, cooling, heating and hot water are established by combining the daily and hourly patterns based on the statistical behavior of the hourly patterns.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.2 no.2
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• pp.83-91
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• 1979

The purpose of this study is to analyze the direct relationship between doctors and number of patients to be treated by applying many kinds of I E's techniques. Generally, doctors in this research work both at OPD & IPD. Under the hospital manegement system that they are applying in, doctor's daily working schedules are instable because the numbers of OPD patients very daily. Therefore, the amount of time they spend for inward Patients are variable too. So the numbers of Patients have great influence to the whole hospital system management. In the first place, the author researched and analyzed a QC of administrative system. Tn the second place, the author carried out Work Sampling with a view for understanding quantity of a doctor's operation. The author suppose this research and analysis is one approach for improving systematic lay-out planning at outpatient waiting room where has many problems to be solved and suggest several process for improvement.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.2 no.2
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• pp.63-81
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• 1979

The purpose of this study is to analyze the direct relationship between doctors and number of patients to be treated by applying many kinds of I E's techniques. Generally, doctors in this research work both at OPD & IPD. Under the hospital manegement system that they are applying in, doctor's daily working schedules are instable because the numbers of OPD patients very daily. Therefore, the amount of time they spend for inward Patients are variable too. So the numbers of Patients have great influence to the whole hospital system management. In the first place, the author researched and analyzed a QC of administrative system. Tn the second place, the author carried out Work Sampling with a view for understanding quantity of a doctor's operation. The author suppose this research and analysis is one approach for improving systematic lay-out planning at outpatient waiting room where has many problems to be solved and suggest several process for improvement.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42
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• pp.1-8
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• 2000

To examine the irrigation water uses in Sunjin river basin, existing status and operation records of headworks facilities including reservoirs, pumping stations, tube wells, and diversion dams were surveyed and analyzed for the period of 1994∼1998. Daily irrigation demand and water use were estimated for the irrigated paddy field using penman equation, Thank model, reservoir water balance model and daily pumping rate of pumping stations. Irrigation water use from multi-purpose dams in the basin was not included in this study.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.858-860
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• 1998

Daily generation scheduling system (DGSC) is a main tool in the power system operation. In Korea, a DGSC was developed in 1982 and it was updated continuously. However, as new type of generators and the number of constraints are introduced. it is very difficult to use the old DGSC. This paper presents a proposal for the development of new DGSC. In the Proposed proposal, line flow constraint and dispatch of combined cycle plant are included.