• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.53 no.9
• /
• pp.481-486
• /
• 2004

In operation of distribution system, $DG_s$ Distributed Generations) are installed as an alternative of extension and establishment of substations and transmission and distribution lines according to increasing power demand. In operation planning of $DG_s$, determining optimal capacity and allocation gets economical pro(it and improves power reliability. This paper proposes determining a optimal number, size and allocation of $DG_s$ needed to minimize operation cost of distribution system. Capacity of $DG_s$ (or economical operation of distribution system estimated by the load growth and line capacity during operation planning duration, DG allocations are determined to minimize total cost with power buying cost. operation cost of DG, loss cost and outage cost using GA(Genetic Algorithm).

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.633-638
• /
• 2009

In this study the performance analysis and cooling capacity of desiccant cooling system incorporating regenerative cooler and direct evaporative cooler in the regeneration air inlet were investigated on the condition of low regeneration temperature and time rotation 180s and area ratio of regeneration to dehumidification section 0.7. The cooling capacity and COP are evaluated at various effectiveness values of the direct evaporative cooler or the regenerative evaporative cooler. As either of effectiveness of the regenerative and direct evaporative coolers of desiccant cooling system increases, both the cooling capacity and COP increase, but effectiveness value of regenerative cooler gives the opposite effect on the system performance. It is found that effectiveness of regenerative cooler less than 0.7 shows the optimum cooling capacity.

• Journal of Electrical Engineering and Technology
• /
• v.13 no.4
• /
• pp.1483-1493
• /
• 2018

Recently, more power facilities are needed to cope with the increasing electric demand. However, the additional construction of generators, transmission and distribution installations is not easy because of environmental problems and citizen's complaints. Under this circumstance, a microgrid system with distributed renewable resources emerges as an alternative of the traditional power systems. Moreover, the configuration of power system changes with more DC loads and more DC installations. This paper is written to introduce an idea of a genetic algorithm-based solution to determine the optimal capacity of the distributed generators depending on the types of system configuration: AC-link, DC-link and Hybrid-link types. In this paper, photovoltaic, wind turbine, energy storage system and diesel generator are considered as distributed generators and the feasibility of the proposed algorithm is verified by comparing the calculated capacity of each distributed resource with HOMER simulation results for 3 types of system configuration.

• STI Policy Review
• /
• v.2 no.1
• /
• pp.55-73
• /
• 2011

Intermediaries are presenting not only transactional information that orchestrates electronic transaction, but also market related information and knowledge useful for sellers' understanding of the market status. However, we do not have strong evidence that the market related information and knowledge is properly utilized by sellers and that it has an actual influence on sellers' performance. According to the research result, absorptive capacity and the pattern of information system utilization is statistically significant to sellers' performance mediated by operational efficiency and market knowledge creation. Especially, explorative utilization of information system and realized absorptive capacity has a stronger influence on sellers' performance mediated by market knowledge creation. With this research result, this study maintains that sellers are required to absorb and utilize market related information and knowledge more actively through explorative utilization of information system to achieve better performance in the e-marketplace. On the other hand, intermediaries are recommended to provide abundant and valuable market related information and knowledge for the sellers to build up better e-marketplaces.

• Journal of Advanced Marine Engineering and Technology
• /
• v.37 no.5
• /
• pp.467-476
• /
• 2013

Freeze concentration method has advantages of high thermodynamic efficiency, low energy consumption and purified water re-use. In this study, freeze concentration waste-water system which was designed as the small and medium sized capacity was analyzed about the rate of electric power consumption and the daily treatment capacity to suggest the direction of system development. At first, power consumption and operation time of the system with fresh water precooler or without it was calculated by computer modeling and analysis. Subsequently, the change of design treatment capacity was applied to the system with fresh water cooler. As a result, the rate of electric power consumption was higher as 0.6 Wh/kg but daily treatment capacity increased in quantity as 19 % in the system with fresh water precooler. As design treatment capacity increased, the rate of electric power consumption was lower and daily treatment capacity was larger in quantity.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.51 no.6
• /
• pp.290-295
• /
• 2002

The present assignment in installing the number of switches for distribution line was made on the basis of a normal feeder capacity 7,000kVA in KEPCO(Korea Electric Power Corporation), Korea. But the normal capacity is revised to 10000kVA in 1998. Even increasing limit of the operating capacity of the distribution lines enables us to give some benefit for the operation flexibility and investment cost of the distribution system. It is disadvantageous in the viewpoint of supply reliability. In distribution systems, switches are equipped to improve the reliability of distribution systems by minimizing the outage section due to fault and maintenance. Utility generally improves the reliability by minimizing the length of outage section, which is caused by fault and maintenance, through switch equipment on distribution system. In order to cope with the changes such as operation capacity, it is necessary to study whether the present criteria is reasonable or not, also to confirm whether the present criteria of installing switches in line is improved or not. In this study, we proposes the number of switch per feeder on the basis of present operation capacity in distribution system.

• IE interfaces
• /
• v.16 no.spc
• /
• pp.111-115
• /
• 2003

Railroad system is consisted of resources of rail track, signal system, and vehicles. Railway operation must use these limited resources and maximize resource utilization. Line capacity(number of trains throughput/day) is determined by such as parameters, line utilization rate($\alpha$), dummy rate for the break-through hour($\beta$), and dummy rate for the number of rail track intervals($\delta$). Line capacity simulation(LCS) determined the line capacity through simulation given $\alpha$, $\beta$, and $\delta$. This paper deals with the development of parameter evaluation simulation(PES). PES presents the decision maker with the relationship of line capacity and measurement of robustness for various scenarios in different parameters and then the decision maker can determine the appropriate parameters.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.59 no.6
• /
• pp.1070-1074
• /
• 2010

In this study we deal with a simple computer simulation algorithm to decide the PRT station capacity. PRT system is different from the conventional rail traffic system in such point that the station is off-line so as to guarantee a very short headway. This characteristic has correlation with the accurate prediction of the line capacity and with the scale of the off-line station. In this paper physical factors and vehicles per hour that are necessary to decide the off-line station scale and the off-line station capacity, respectively, are shown through a simple compter simulations.

• Journal of Biomedical Engineering Research
• /
• v.12 no.1
• /
• pp.35-42
• /
• 1991

In this paper, the information capacity, the intergrate performance measure of digital radiography system has been quantitatively analyzed. The effect of various factors affecting the information capacity of the digital radiography system in multistage detection processes has been considered and analyzed In detail. The results show that the more information capacity can be obtained with the smaller detector cell area, despite of the reduced signal to noise ratio due to the reduced number of X ray photons per detector cell. Considering the limit of human visual acuity, however. the sufficient resolution will be obtained when the detector cell size in $0.2{\times}0.2\textrm{mm}^2$ with 8 bit quantizaion. And also the results indicates that the information capacity may be severely reduced by the mixture of electric noise in final read-out stage.

• IE interfaces
• /
• v.25 no.4
• /
• pp.431-440
• /
• 2012

Since pooling is a popular scheme in many areas to attain operational excellence, many researchers investigated the performance of pooling systems. However, rare research could be found on pooling with game situation which has much applicability to real world phenomenon. We analyze the performance of noncooperative pooling system with two servers having different sharing capacity. We investigate the sensitivity of the advantage of capacity pooling on the variation of system parameters, including sharing capacity numbers, pooling probability, pooling strategy and traffic intensity. As a result, we suggest an efficient control policy which facilitate the performance of pooling in a game situation.