• The Journal of Korean Society for Radiation Therapy
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• v.6 no.1
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• pp.21-30
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• 1994

To analyze the states of operation of radiotherapy facilities in the period from 1979 to 1992 and to get the base for efficient operation and maintenance of the radiotherapy facilities. Data on the records of annual number of patients operated by each facility; span of suspension of operation, the cost and span of repairing, and parts of oui-of-order in the period from 1979 to 1992 were analyzed. We made a comparative analysis of average annual number of patients, annual span of the suspension of operation, annual cost ratio of repair, span of repairing per break down, and total number of broken parts. We could get following annual number of patients(day), span of the suspension of span ($\%$)(day). annual cost ratio fo repair($\%$), span of repairing per break down(Min-Max, day), and number of broken parts from this analysis. 1. Cobalt unit (Picker C-9) : 10,389(43), 0.4(0.83) 0.07, 1hr-2, 3 2. Linac(Clinac 6/100) : 11,492(50), 4.0(9.57), 0.98, 1hr-30, 12 3. Linac(Clinac 18) : 9.115(44), 12.7(30.5), 3.54, 1hr-108. 41 4. Simulator(Picker Ther-X) : 2,017(9), 0.51(1.3), 0.24, 1hr-2, 7 5. RTP(Capentec Cap-plan) : 528(2), 0.4(0.93), - hrs, - The conclusion obtained from statistical analysis above are as follows. 1. The rate of operation of Cobalt unit($99.6\%$) was higher that of Linear Accelerators ($87.3\%$). The rates operation of Simulator and RTP computer were very close to that of Cobalt unit. 2. In order to raise up the working ratio of accelerator. it is desirable that we keep our engineer to learn a sufficient technical skill and the equipment agent to stock sufficient spare parts. 3. In order to maintain Linear Accelerator efficiently, it is desirable to have annually $2.3\%$ of the purchase price of equiment for repairing.

• Journal of Korean Institute of Architectural Sustainable Environment and Building Systems
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• v.12 no.6
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• pp.669-679
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• 2018

Energy consumption savings in buildings should be reviewed in diverse areas such as air conditioning system and lighting responsible for cooling and heating, and energy management systems such as BAS (Building Automation System) and BEMS (Building Energy Management System) are introduced to improve energy consumption efficiency and to promote economic control of related facilities by integrated management of energy generated and consumption in buildings. The measured building of this study uses regenerative geothermal system. Measured values of heat pump and system COP were 4.7 and 4.2 respectively, and they were found to be higher 11.9% and 23.5% than rated values. As a result of analyzing the air conditioning and lighting energy from the first floor to the fourth floor performing the air conditioning, the second and third floors, which have a high frequency of use, are compared with the first and fourth floors 50% higher energy consumption ratio. On the other hand, the general heat storage system uses the nighttime power of the previous day to store heat and use it the next day. The total number of days of abnormal operation during the summer season is 61 days. The electricity cost corresponding to the abnormal operation is 1,840,641 KRW, and the normal operation using the nighttime power is 1,363,561 KRW, which is difference of 477,080 KRW, 35% increase in cost. We will utilize it as the main data of BEMS through analysis of winter operation characteristics as well as summer operation characteristics.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.6
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• pp.850-861
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• 2013

This study aimed at investigating any differences perceived between the contractor and the contractee based on an importance-performance analysis (IPA) of foodservice quality attributes. Questionnaires were distributed to 200 personnel concerned in the Busan, Ulsan and Kyungnam areas and a total of 134 valid responses were used for analysis. Of the 23 foodservice quality attributes, the factors of 'food quality', 'employee service', 'hygiene and safety', 'customer orientation' and 'operation quality' were induced from a scale purification process through the exploratory factor analysis. The level of importance (p<0.01) of the 'hygiene and safety' factor and 'employee service' factor was not found to be significantly different between the groups. In the level of performance, the factors of 'food service', 'employee service', 'customer orientation' and 'operation quality' were found to be perceived significantly lower than expected by the contractor group. In the importance level, 'food quality', 'employee service', 'hygiene and safety', 'customer orientation' and 'operation quality' were rated by the contractor as 4.03, 4.30, 4.27, 4.01 and 4.12 points, respectively. In contrast, in the performance level, perceived 'food quality', 'employee service', 'hygiene and safety', 'customer orientation' and 'operation quality' were evaluated as 3.57, 3.94, 4.06, 3.83 and 3.95 points, respectively.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.4 s.27
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• pp.233-239
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• 2006

This paper aims to evaluate the operation efficiency of Korean RCC(Rescue Co-ordination Center)/RSC(Rescue Sub-Center) using DEA(Data Envelopment Analysis). for this evaluation, this paper use the quantitative data for DEA analysis with two inputs and four outputs and a qualitative data analysis with the use of expert assessment. The tool for integrating heterogeneous data is fuzzy logic model to decision support system. In this paper, therefore, RCC/RSC evaluates the priority for operation efficiency. The result are found as order as Inchon, Mokpo, Jeju, Donghae, Busan, Pohang, Yosu, Sokcho, Tongyeong, Ulsan, Taean, Gunsan RSC.

• Journal of Korean Society on Water Environment
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• v.28 no.6
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• pp.851-858
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• 2012

This study conducted a result analysis on operation of 26 Rural Community Sewage Treatment Plant (RCSTP) newly constructed in Yeong-yang, Bong-hwa and An-dong areas which are located at the upper region of An-dong Dam and Im-ha Dam. Based on operation result, an analysis on characteristics of sewage in each area and the treatment efficiency of the installed treatment process was conducted. The result of analysis on characteristics of sewage has shown the difference in concentration of the sewage according to area characteristics. Sewage in areas with frequent occurrence of agricultural water and livestock wastewater had high concentration. It is important to select the most suitable treatment process when selecting a treatment process for RCSTP according to properties of sewage in each area. As a result of operation, the disposal efficiency for organic matter and suspended solids was stable with less fluctuation, but the disposal efficiency for nitrogen and phosphorus showed high fluctuation. This signifies that it is necessary to pay attention to operation condition management of nitrogen and phosphorus when operating RCSTP.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.2
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• pp.45-53
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• 1998

This paper describes the development of educational and training package with Integrated graphic environment for power system analysis '||'&'||' operation. This package runs on a personal computer with interactive scheme and includes a graphic editor for modeling of power system, a database system, the various graphic illustration '||'&'||' animation modules to represent the simulation results, and the application module of the power system analysis '||'&'||' operation. The proposed package is tested on a sample system, the package will be useful for the education and training of power system analysis and operation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.10C
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• pp.921-932
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• 2002

In this research, we seek to identify an effective operation management strategy of telecommunication systems. In order to develop operation management strategies, we implement a quantitative techno-economic analysis. We evaluate related issues and factors, and apply the developed method to PSTN switching systems. In the proposed techno-economic modeling, we apply a well-known factor analysis technique-analytic hierarchy process-to evaluate PSTN operation management strategies. Then, we implement a decision analysis methodology to evaluate the cost of proposed strategies. We evaluate the proposed methodology by using available real data of the PSTN system. The primary impact of this research will be realized in helping PSTN operator select the best operation management strategy of PSTN system.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.4
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• pp.269-279
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• 2019

This study would present a risk analysis method to evaluate stable tap water supply in a multi-regional water supply system and propose a measure for the evaluation of the effect of the conjunctive operation of the multi-regional water supply system using this. Judging from the vulnerability for the crisis response of the entire N. multi-regional water supply system, as compared to the result of Scenario 1 in which no conjunctive pipes were operated, it was found that in Scenario 2, in which conjunctive pipes were partially operated, the vulnerability of crisis response decreased by about 30.6%, and as compared to Scenario 3, the vulnerability of crisis response decreased by 86.2%. In setting a plan for stable tap water supply in N multi-regional water supply system, using the estimated value and the method for the evaluation of the vulnerability of crisis response by pipe, by interval and by line, it is judged that this can be utilized as a basis for the judgment of the evaluation of the operation or the additional installation of conjunctive pipes.

• Journal of the Korean Society of Safety
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• v.35 no.1
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• pp.12-17
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• 2020

This paper analyzes functions of component parts of D-Urban Railway's door system along with operation obstacle risks on frequency(the number of occurrences/year) and severity(delay time/the number of occurrences). Based on this, the paper presents improvements and current system's problems after obstacle risks of EMU and door system are appled. The obstacle of door system causes corrosion of main parts such as DCU due to heat problem of operation environment, problems of maintenance methods and deterioration. DCUs on PCBs with more than 50% pattern corrosion cause problems. Even though the number of door system's obstacle occurrences for the last 5 years is 42, along with 104 minutes of operation obstacle, EMU operation obstacle risk is low(Level 1), which indicates there is limit in matrix of railway risks presented by the standard of railway safety management system. Therefore, it is necessary to have railway risk matrix suitable for the field. Finally, the paper deducts the obstacle risks through frequency and severity. Since 2017 when the risks of EMU and door system's obstacle, that of EMU has been 24(47% reduced) and that of door system has been average 9.5 per year(23% reduced).

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.14 no.2
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• pp.15-22
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• 2018

As heat pump application has been extending to residential, commercial, and industrial fields, the heat pump should have many operation modes. It is required to optimize refrigerant charge amount at all operation modes in order to enhance the annual performance of heat pumps. In this study, the performance analysis of the heat pump which has cooling, heating, cooling-hot water, heating-hot water, and hot water modes was executed with the variation of refrigerant charge amount. As the refrigerant charge amount changed, the maximum COPs of the heat pump at different operation modes were changed within ${\pm}10%$. Therefore, it is highly recommended to select optimum charge amount for the heat pump based on the analysis of annual load for each operation modes.