• Magazine of the Korean Society of Agricultural Engineers
• /
• v.36 no.2
• /
• pp.44-55
• /
• 1994

This paper describes the development of real-time irrigation reservoir operation models that adequately allocate available water resources for paddy rice irrigation. Water requirement deficiency index(WRDI) was proposed as a guide to evaluate the operational performance of release schemes by comparing accumulated differences between daily release requirements for irrigated areas and actual release amounts. Seven reservoir release rules were developed, which are constant release rate method (CRR), mean storage curve method(MSC), frequency analysis method of reservoir storage rate(FAS), storage requirement curve method(SRC), constant optimal storage rate method (COS), ten-day optimal storage rate method(TOS), and release optimization method(ROM). Long-term forecasting reservoir operation model(LFROM) was formulated to find an optimal release scheme which minimizes WRDIs with long-term weather generation. Rainfall sequences, rainfall amount, and evaporation amount throughout the growing season were to be forecasted and the results used as an input for the model. And short-term forecasting reservoir operation model(SFROM) was developed to find an optimal release scheme which minimizes WRDIs with short-term weather forecasts. The model uses rainfall sequences forecasted by the weather service, and uses rainfall and evaporation amounts generated according to rainfall sequences.

• Proceedings of the KIEE Conference
• /
• 2003.07d
• /
• pp.2358-2361
• /
• 2003

In this paper, parallel control method that enables coordinating operations of multiple mini ice storage air conditioner is proposed based on LonWorks system. The proposed parallel control method is a kind of master/slave control method based on LonTalk network communication. In the control method, master controller leading whole system operations is determined by date to avoid the disproportion of outdoor unit operations. In addition to the above, duty shift control method is proposed to avoid redundant operations of outdoor units and to equalize the operation frequencies of them. Through some simulation tests, the proposed parallel control method and the duty shift control method are evaluated and the efficiencies of them are validated by comparing with existing methods.

• Science of Emotion and Sensibility
• /
• v.14 no.1
• /
• pp.7-16
• /
• 2011

This is a study on operation system's application method for leading-in public bike operation system through researching on case study at home and abroad, and situation research in Naju city. In the 1st research, studied about the main problems showed at application cases of public bike system at domestic and overseas, such as using time, danger for be stolen and damaged. 2nd research focuses on necessarily of leading-in operation system to be used easily by city residents and travelers of Naju City which is the scheduled city for leading-in public bike system. 3rd research is on the basis of the result showed in 1st and 2nd research, supplied some problems' solving method for France Veblib System, such as lending and rental process using mobile, system operation process, communication process. Also, supplied the application method for problems showed at 1st and 2nd research and civil service proposal. The leading-in method study on public bike operation system was done through above research, also case study at home and abroad, situation study, and rental program module development, and this operation system is worked as an model operation system in Naju City. The future study of leading-in operation system will be more effective by means of summing up test running result.

• Architectural research
• /
• v.7 no.1
• /
• pp.11-18
• /
• 2005

In today's building industry the emphasis has been geared more towards construction, thus building maintenance and life cycle have been neglected until now. A direct result of this neglect is the rapid aging of building, which leads to more cost-effective decision making methods for the prolongation of building life span. The following study is conducted in the area of Daegu and Seoul in order to develop the estimation analysis method of the annual operation cost of the Korean high-rise condominiums for the cost-effective decision making support through mathematical and statistical analyses including the present value and standardized measurement corrections. Based on the assumption that the life expectancy of the high rise condominium is 50 years, initial cost is ￦421,212/$m^2$, and a total sum of yearly operation cost during life expectancy is ￦2,154,499//$m^2$), yearly accumulated operation cost is shown as below: $AOC=0.7097t^4-38.803t^3+806.95t^2+11045t-496.52$ ($R^2=0.98$) (Here, AOC = Accumulated Operation Cost, t = given years)

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.16 no.4
• /
• pp.24-30
• /
• 2020

Ground source heat pump (GSHP) systems are actively introduced as cooling and heating conditioning systems of buildings due to annual stable performance and easily maintenance. However, ground temperature imbalance is occurred when the GSHP is used for a long period. Therefore, in this study, we proposed the operation method of the system that considered the recovery time of heat source temperature. The entering water temperature (EWT) and heat exchange rate (HER) were comparatively analyzed according to the continuous and intermittent operation. Furthermore, the underground thermal environment was evaluated by numerical analysis model. As the result, the intermittent operation was a maximum of 12.3% higher HER during the heating period than the continuous operation. In addition, the overall ground heat source temperature at the intermittent operation was higher than it at the continuous operation.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.05a
• /
• pp.341-343
• /
• 2012

This study introduces a method for computation of process and operation gap in the specific construction operation(i.e., RC frame construction applying a block-grouping scheme) using CYCLONE-based simulation modeling and analysis technique. Since uncertainty of construction environment exists, a thoughtful production planning is required to effectively deal with a risk resulting in schedule delay in advance. This study presents the concepts of a time delay occurred in a process level and operation level in a operation model, and a method of measuring gap-times in each level while the simulation progresses. It helps a site manager to decide how many segmentation in a construction block is suitable for eliminating unproductive time-delays under the constrained resources (e.g., laborer, equipment). A case study presents a network model representing a three segmented RC frame work, and result obtained from the simulation experiment.

• Proceedings of the KSR Conference
• /
• 2003.10c
• /
• pp.145-150
• /
• 2003

The national subway went under construction in 1971, and after three years of endeavor, Seoul subway line number one opened for traffic in 1974. Line number two went under construction in 1978 and it opened for traffic in 1984. With the use of safety operation for more than 20 years, the life cycle nearly came to an end. Therefore the improvements for the safety operation are unavoidable. The total system should not be affected when the new and conventional systems are overlapped, the system operation is in the initial stage, and it confronts the situation of abnormal operation. However, there is a total lack of experience in construction and improvement for the trains that are in the use of large transport and density headway. In this paper, we propose an improvement method of the subway signalling system using ATO (Automatic Train Operation control scheme) to which the latest Digital ATC is applied, and examine the first application model of ATO system.

• Journal of the Korean Society of Safety
• /
• v.29 no.4
• /
• pp.191-198
• /
• 2014

In the event of continued train operation being impossible as the result of a breakdown, it will be essential to dispatch a relief train to recover the broken down train. Operation of relief train carries with the risk of collision in the process of connection with broken down train. The present study looks at the suitability of risk management procedures and associated problems in the light of case studies of relief train operation, and of national legal standards and railroad company regulations. It looks at appropriate methods of risk management and the problems that can arise. Based on the study a method is proposed of operating the relief train which is consistent with appropriate risk management. The proposed method will improve the safety of relief train operation, It is hoped that the results of the study will be reflected in relevant laws and operating company regulations, and so contribute to enhancing the overall level of railroad safety.

• International Commerce and Information Review
• /
• v.10 no.4
• /
• pp.203-219
• /
• 2008

This study shows the following results. First, the assessment items of the whole exhibition operation, workforce, counselor's ability, facility and environment were important analysis factors for exhibition recognition, quality of human operation and quality of exhibition facility and environment. Second, exhibition recognition was found to be the most significant factor that influenced exhibitor's cognitive achievement, exhibition employee operation and exhibition facility. Third, exhibitors' satisfaction simultaneously increased as exhibition recognition and employee operation quality were raised. However, exhibition facility didn't strongly influence exhibitors' satisfaction. Fourth, high exhibition recognition, employee operation and exhibition facility resulted in high cognitive achievement and exhibitor's loyalty. Fifth, exhibition recognition is a highly influential factor to mediate exhibitor's cognitive achievement and exhibitors' loyalty. It implied that exhibitors' cognitive achievement and satisfaction were significantly related to the exhibition quality factor. Moreover, it indicated the effective and efficient operational method to strengthen promotional strategy, enhance the quality of employee operation, exhibition facility and environment. Thus, the results suggest a new method to evaluate exhibitor's satisfaction in the exhibition industry.

• Journal of the Korean Society of Industry Convergence
• /
• v.25 no.6_2
• /
• pp.1003-1008
• /
• 2022

This paper proposes a method related to fault tolerance operation and characteristic analysis of asymmetric 6-phase permanent magnet synchronous motor. In general, motor drive systems with multi-phase structures can be continuously operated despite a reduction of power and speed by using a phase changeover or control techniques according to the failures. As a result, it is widely used in industrial fields such as aviation and defense, which require high efficiency and high reliability. In this paper, the second order ripple of the electrical fundamental freuqnecy occurs in the dq-axis currents of the synchronous coordinate system through mathematical analysis according to the switch open of the dual 3-phase inverter. Therefore, the fault tolerant operation method is presented by applying the fault detection method with a constant cycle for continuous operations. The effectiveness of the proposed fault tolerance operation method is verified through the several experiments.