• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.486-492
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• 1999

One of the purpose of the reservoir operation is minimizing theinnudation area in the downstream reaches during flood period.l To execute the gate operation properly , it requires lots of real-time data such as rainfall, reservoir level, and water level in the downstrea. Gate operation model was developed with the flood discharge obtained from real-time flood forecasting model and the criterion prepared from the past history of gate operation. Water level in the downstream would be increased by the releasing discharge from the spillway and the area of paddy land flooded in a certain detph and time would be estimated usnig GIS map. Gate operation model was applied to the Yedang reservoir, and the flooded area, depth and time in the paddy land was estimaged.

• Journal of KSNVE
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• v.11 no.2
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• pp.249-256
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• 2001

In this paper the characteristics of vibration induced by subway trains running on track is discussed. The quantitative prediction of the vibration level and the countermeasure for reduction of necessary, is of importance for the better environment. It was made the constructed Bundang line as first step with the modified Young-Dan type to basis on the Japanese Young-Dan type. In this paper it was measured and analyzed to two region ($ \circled1$Susuh-Bokjung. $ \circled2$Chorim-Suhyun region) of this. at present, operational Bundang line when averaging velocity of train is 60 (km/h). As the response characteristics of frequency Induced by subway operation, it was confirmed that frequency band of neighborhood of 30~80 Hz in generally dominant. Also to assess the quantitative nitration as response level to be measured for each point of two region in subway operation, the vibrational response level was measured at the state to be not subway operation. And the level was approximately $\fraction one-fifth~\fraction one-ten$ level comparing to subway operation.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.5
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• pp.160-170
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• 2007

This study predicts Life Cycle Cost of RC Slab bridge case in maintenance and operation level and calculated economic efficiency by the avoidable costs of a bridge. This result of the study can be summarized as follow: (1) LCC analysis model on the bridge case is suggested. (2) Maintenance and operation level of a bridge have been divided, and LCC of the bridge case has been predicted at current maintenance and operation level and required maintenance and operation level. (3) Reduction costs is predicted by LCC of the bridge case, and its economic efficiency is calculated.

• The Korean Journal of Community Living Science
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• v.26 no.4
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• pp.683-696
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• 2015

This study measures patients' meal satisfaction according to the type of operation (self-operation and contract operation) and identifies improvement areas. A survey was conducted using 183 contract operation patients and 60 self-operation patients receiving general meals. The mean score for satisfaction for the whole sample was 3.42 (self-operation = 3.51; contract operation = 3.39), and self-operation satisfaction was significantly higher than contract operation satisfaction. Mean scores were 2.98 for food, 3.26 for menu composition, 3.57 for sanitation, 3.78 for distribution meal services, and 3.50 for menu information. Self-operation showed a higher satisfaction level than the contract operation in food and menu composition. The ccontract operation showed a higher level of satisfaction than self-operation in sanitation, distribution meal services, and menu information. In terms of feeling dissatisfaction with meal services, both groups showed the highest dissatisfaction with food and menus, and both groups agreed on food and menus that required the greatest improvement. Based on the results, contract operation managers should develop and apply menus considering their preferences. Dietitians of self-operation strengthen communication between meal service staff and patients by carrying out periodic and systematic service education on self-operation.

• The Korean Journal of Health Service Management
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• v.4 no.1
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• pp.11-22
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• 2010

The purpose of this study is to approving the usefulness on Customer Satisfaction of Human Bridge. To achieve this purpose, we conduct a survey of 385 Customer to have a new operation analysis that so-called Human Bridge. The results of this study as follow. First of all, It's appeared that dependence on mass communication has a high level Because that Some 66% of the people surveyed say that they have Human Bridge operation by mass communication. Secondly, In case of satisfaction level connected with operation, some 66% of the respondents say that it is inconvenient or not at all in the Human Bridge operation and some 81% of the respondents say that it is very healthy or the same in the gum condition. On the other hand, Some 64% of the people surveyed say that it is inconvenient or extra comfortable in the masticate their's food well. Thirdly, In case of the level of teeth shaking, Some 90% of the people surveyed say that it is no change or small to contrast beginning, and in aesthetic satisfaction after operation, a surprising 93% of the people surveyed say that it is satisfaction.

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.294-296
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• 2000

Energy recovery in the regenerative region is very important when SRM(Switched Reluctance Motor) is used in traction drive. This is because that to reduce energy loss during mechanical braking and/or to have a high efficiency drive during braking. To control excitation voltage in motor operation and regenerative voltage in the generator operation in the SRM, multi-level voltage control is effective. This paper suggests multi-level inverter which is useful for motoring and regenerative operation in SRM.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.9
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• pp.1240-1248
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• 2013

This paper describes a switching-level operation analysis of BTB(Back-To-Back) converter for HVDC(high voltage DC) application based on MMC(modular multi-level converter). A switching-level operation analysis for BTB converter is very important to understand the converter operation in detail and check the voltage and current transients in each components. However, the development of switching-level simulation model for the actual size BTB Converter is very difficult because the MMC normally has more than 150 sub-modules for each arm. So, a switching level simulation model for the 11-level MMC-based BTB converter was developed with PSCAD/EMTDC software, which has 12 sub-modules for the positive arm and another 12 sub-modules for the negative arm. The DC-voltage balance algorithm, the circulating-current reduction algorithm, the harmonic reduction algorithm, and the redundancy operation algorithm were included in this simulation model. The developed simulation model can be utilized to analyze the MMC-based BTB converter for HVDC application in switching level and to develop the protection scheme for the MMC-based BTB converter for HVDC application.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.461-463
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• 2016

Information security and preservation of customer's data privacy are key factors for further wide spread adoption of microgrid (MG) technology. However, strong coupling between the operation cost of multi-microgrid (MMG) system and privacy of customer data makes it more challenging. A nested energy management system (EMS) has been proposed in this paper. The surplus/shortage information from the inner level MGs is included in processing the optimal operation of outer level MGs. This type of optimization ensures a layered privacy-preservation to customer at each MG level. The proposed EMS architecture is a better trade-off architecture between the operation cost of the MMG system and customer privacy-preservation at each level of MG.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.337-342
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• 2018

A rain water pumping station is a structural countermeasure to inland flooding of domestic water generated in a urban watershed. In this study, the optimal operation water level of the pump with the minimum overflow was determined based on the opinions of the person in charge of the operation of the rain water pump station. A GA (Genetic Algorithm), which is an optimization technique, was used to estimate the optimal operation water level of the rain water pump station and was linked with SWMM (Ver.5.1) DLL, which is a rainfall-runoff model of an urban watershed. Considering the time required to maximize the efficiency of the pump, the optimal operating water level was estimated. As a result, the overall water level decreased at a lower operating water level than the existing water level. For most pumps, the lowest operating water level was selected for the operating range of each pump unit. The operation of the initial pump could reduce the amount of overflow, and there was no change in the overflow reduction, even after changing the operation condition of the pump. Internal water flooding reduction was calculated to be 1%~2%, and the overflow occurring in the downstream area was reduced. The operating point of the pump was judged to be an effective operation from a mechanical and practical point of view. A consideration of the operating conditions of the pump in future, will be helpful for improving the efficiency of the pump and to reducing inland flooding.

• Journal of Korean Neurosurgical Society
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• v.53 no.2
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• pp.125-128
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• 2013

A 65-year-old man who had lateral cervical disc herniation underwent cervical posterior laminoforaminotomy at C5-6 and C6-7 level right side. During the operation, there was no serious surgical bleeding event. After operation, he complained persistent right shoulder pain and neck pain. Repeated magnetic resonance image (MRI) showed diffuse cervical epidural hematoma (EDH) extending from C5 to T1 level right side and spinal cord compression at C5-6-7 level. He underwent exploration. There was active bleeding at muscular layer. Muscular active bleeding was controlled and intramuscular hematoma was removed. The patient's symptom was reduced after second operation. Symptomatic postoperative spinal EDH requiring reoperation is rare. Meticulous bleeding control is important before wound closure. In addition, if patient presents persistent or aggravated pain after operation, rapid evaluation using MRI and second look operation is needed as soon as possible.