• Journal of electromagnetic engineering and science
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• 제2권1호
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• pp.1-4
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• 2002

Performance improvement of the DS-CDMA system by the spectrum-overlap is important for better service quality or more system capacity. In this paper, an analysis thor capacity improvement is newly considered when the Lanczos chip waveform is used for the spectrum-overlapped DS-CDMA system. RC(relative capacity) is the ratio of the capacity of overlapping system to that of non-overlapping system, which is used for the expression of the capacity improvement. The optimal overlapping ratio is numerically found to make the maximum capacity improvement When the rectangular chip waveform is used far the overlapping system, maximum capacity improvement is increased by about 10% at the required BER=$10^{-3}$TEX> and the optimal overlapping ratio is 1.23. When the 95 % power bandwidth is considered for the Lanczos chip waveform, maximum capacity improvement is increased by 34.4% at overlapping ratio of 1.55 when the required BER is $10^{-3}$TEX>. The lower required BER far the better communication quality makes gradually smaller capacity improvement.

• 산업경영시스템학회지
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• 제34권3호
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• pp.49-56
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• 2011

Estimating optimum hardware capacity of an e-learning system is very important process to grasp reasonable size of designing technique architecture and budget during step of ISP(information strategic planning) and development. It hugely influences cost and quality of the whole project. While investment on information system hardware has been continuously increased, there was no certified hardware capacity estimating method in e-learning system development. A guideline for hardware sizing of information systems was established by Telecommunication Technology Association in 2008. However, the guideline is not appropriate for estimating optimum hardware capacity of an e-learning system because it was designed to provide general standards for estimating hardware capacity of various types of projects. The purpose of this paper is to provide a methodology for estimating optimum hardware capacity in e-learning system development. To develop the methodology, this study, first of all, analyzes two e-learning development projects, in which the guideline was applied to estimate optimum hardware capacity. Then, this study finds out several key factors influencing on hardware capacity. Finally, this study suggests a methodology for estimating optimum hardware capacity of an e-learning system, in which weights for the factors are determined through AHP analysis.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.1612-1615
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• 2009

Water supply reliability indexes (WSRI) is estimated for assessment of water supply capacity in the downstream for parallel reservoir system in Nakdong River, South Korea, using allocation rule (AR) according to the water supply capacity of each reservoir and the characteristic of parallel reservoir system. The result of the analyzing parallel reservoir system for Andong and Imha reservoir in Nakdong River does not include evidences available enough to decide whether the results of water supply analysis are excellent in the current reliability evaluation or not. However, AR (C) shows a good result in the water supply capacity for each reservoir based on the connected operation system and the total water supply capacity at the control point of downstream by the average water supply capacity and possible range of water supply capacity suggested by this study. The average water supply capacity is analyzed by the reliability of monthly average water supply capacity. Furthermore, the possible range of water supply capacity is estimated by the standard deviation when water deficit occurs. Therefore, AR (C) is useful to establish and estimate the planning water supply capacity according to the monthly water supply condition and the possible range of water supply capacity when the water supply capacity deficit occurs, South Korea.

• 대한전기학회논문지
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• 제35권7호
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• pp.285-295
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• 1986

This study is to investigate the stability of expanded new generator plant depending on the capacity of existing system. We examined the transmitting power limit to the existing system as its capacity increase for the various system configuration with fixed location of plants and substations. The results show that the stability has decreasing tendency when the existing source capacity increase. Thus it can be concluded that new generator has little stability problem when it connected to small system, whereas large existing system capacity gives remarkable difficulty in adopting new generator.

• 전기학회논문지
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• 제65권5호
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• pp.804-810
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• 2016

Photovoltaic system construction of the module capacity in domestic is specified criteria to less than 105% of the inverter capacity. However, the modules are installed in the outdoor actual output is reduced due to factors such as the irradiation intensity, module surface temperature. Thus, it needs the capacity of the inverter to be designed according to the actual module output. In this paper, the first approach to find the actual module output is to analyze the actual PV system monitoring data. Next, four sites where the loss analysis, system utilization, inverter utilization, and the ratio of the inverter overload are performed using PVSYST software. By changing the ratio of the module capacity, the inverter capacity of the site B is confirmed 20% less than the module capacity. Site A, C, D are identified as the ratio of the inverter capacity is 10% less than the module capacity.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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• pp.696-703
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• 2000

This paper describes the capacity calculation of power supply system for light Rail Transit Three factors are considered for the design i.e. substation arrangements, line configuration and substation power capacity. In this study, we considered all of them for capacity calculation of power supply system for LRT. At first DC-fed-traction system is introduced on an outline, a characteristics of train and fed network, and design method of substation arrangements. Optimal design procedures are described, and program for capacity calculation of the system is presented. In addition, the computer simulated results are computed with the conventional simple calculation method.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(1)
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• pp.49-52
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• 2001

A virtual antenna system is presented to increase the channel capacity of a smart antenna in cdma2000. Although a smart antenna system can increase channel capacity by forming a beam to a desired user direction, an increase of channel capacity is limited by the number of antenna elements. A virtual antenna is proposed to improve the channel capacity by increasing the degree of freedom. The results show that the proposed system has a larger channel capacity than a conventional smart antenna system for the same number of antenna elements.

• 무역상무연구
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• 제17권
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• pp.147-167
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• 2002

In this paper, I investigated and analysed of the utilization of logistics information system in Korean firms - key factors of logistics management capacity, capacity of logistics information technology management, utilization of logistics information system and logistics outcome. I come to the conclusion that the higher firms are management capacity and capacity of logistics information technology management, the better firms utilize logistics information system, and the better these firms are logistics outcome, that is, the higher to promote logistics service and to reduce logistics cost.

• 대한전기학회논문지:시스템및제어부문D
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• 제49권8호
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• pp.481-490
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• 2000

This paper analyzes interference power, Erlang capacity, the number of handoff occurrences, and call blocking probability with respect to the cell radius, the soft handoff region, and the mobile's velocity in a CDMA hierarchical cellular system. The microcell cellular system has the higher Erlang capacity than the macrocell cellular system. However, the microcell cellular system, which has a high system capacity through frequency reuse has the call blocking probability higher than macrocell cellular system. Also the interference power and the call blocking probability are decreased with the operation of soft handoff. Therefore, this paper presents the optimization of soft handoff region so as to maximize system's Erlang capacity with the low the call blocking probability according to mobile's velocity in the CDMA hierarchial cellular system.

• 전기학회논문지
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• 제56권2호
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• pp.233-239
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• 2007

As the Kyoto Protocol, which aims at reducing greenhouse gases in accordance to the UNFCCC, came into force, research on environment friendly energy resources has been a matter of concern worldwide. As a general power generation system, among renewable energy resources, that is interconnected and operated with power system, the wind turbine is emerging as an effective alternative. Since power capacity of the wind turbine has been steadily increasing and its relative importance is also increasing in total facility capacity, we cannot ignore its effect. Because controlling generation output in the wind turbine is not as easy as in the synchronous machine due to its facility characteristics and it generates irregular output fluctuations when interconnected with power system, system interconnection was difficult. But the effect of large capacity wind turbine on isolated power system like Jeju island is serious problem on the frequency stability. Accordingly, it is necessary to analyze the effects of wind turbine on system interconnection and assess the optimum capacity of wind turbine that satisfies the most important principle of stable power supply. This paper have analyzed the effects of wind turbine capacity increases on the system and suggested the method of the capacity to achieve its steady operation. And It is applied to the Jeju island.