• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 추계학술대회 논문집
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• pp.219-222
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• 2009

Microgrid is a small-scale power system composed of distributed generators, energy storage system and loads, and can operate in the grid-connected mode and the islanded mode. This paper presents optimal design procedures for remote microgrid. The design program is based on the economic evaluations including the feasibility study module, optimal combination and allocation of DER, power network design and the reduction of the GHG emmission. This program which is suggested in this paper shows good performance as a tool of remote microgrid design.

• Journal of Ecology and Environment
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• 제31권1호
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• pp.17-21
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• 2008

Mating behaviour of the gammarid amphipod, Hyale rubra, was observed. H. rubra displayed precopulatory mate guarding: males clasped females with their gnathopods during copulation, forming a pair. Males also participated in embryo care during the incubation period. The population was small, and the sex ratio was almost equal. Energy allocation for mating effort and parental effort in the two sexes appear to be almost equal. The mating system was sequentially polygamous (or promiscuous) and there was conspicuous sexual dimorphism in the size of the gnathopod, which was used for mate guarding. However, there appears to be relatively weak sexual competition for mating opportunities despite conspicuous sexual dimorphism. H. rubra did not display territorial competition or external fertilization. Nevertheless, the male provided paternal care. Since H. rubra inhabit tide pools and live on algae, the polygamous mating system of the species can be explained by the polygyny threshold model. The evolution of mate guarding and parental care may have been favored by the species' low population density and harsh environments, an interpretation consistent with the optimality model.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권11호
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• pp.3955-3966
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• 2014

With the exponentially increasing Internet traffic and emergence of more versatile and heterogeneous applications, the design of datacenter networks (DCNs) is subject to unprecedented requirements for larger capacity and more flexible switching granularities. Envisioning Optical-Orthogonal Frequency Division Multiplexing (O-OFDM) as a promising candidate for such a scenario, we motivate the use of O-OFDM as the underlying switching technology in order to provide sufficient switching capacity and elastic bandwidth allocation. For this purpose, this article reviews the recent progresses of DCN deployment and assesses the scenario where the O-OFDM transmission and switching technology is employed in the underlying transport plane. We discuss the key issues of the datacenter-oriented O-OFDM optical networks, and in particular, elaborate on a number of open issues and solutions including system interconnection architecture, routing and resource assignment, survivability, and energy-efficiency.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권12호
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• pp.5328-5346
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• 2016

An optimal power control algorithm based on convex optimization is proposed for base stations in long term evolution networks. An objective function was formulated to maximize the proportional fairness of the networks. The optimal value of the objective function was obtained using convex optimization and distributed methods based on the path loss model between the base station and users. Field tests on live networks were conducted to evaluate the performance of the proposed algorithm. The experimental results verified that, in a multi-cell multi-user scenario, the proposed algorithm increases system throughputs, proportional fairness, and energy efficiency by 9, 1.31 and 20.2 %, respectively, compared to the conventional fixed power allocation method.

• 대한인간공학회지
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• 제25권4호
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• pp.1-7
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• 2006

The purpose of this study is to develop an efficient algorithm for the management of the shift schedule in nuclear power plants in consideration with the ergonomic criteria and the regulatory codes. The ergonomic criteria considered are the work hours, overtime-work frequency and working time, start and finishing time of works, allocation of rest times and duty-offs, rotating of shifts, etc. to comply with the regulations such as the Labor Standard Act, the ILO Convention No. 171, 178, "the detailed content of a periodic safety review," enforcement regulations 19-2 of the Atomic Energy Act. The developed algorithm for the shift schedule program adopts a heuristic method to minimize the difference the workload for shift workers in nuclear power plants.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.333-334
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• 2006

In this study, information compression based on the wavelet technique is described. The principle of signal or image compression is performed by optimization of quantization, that is the bit allocation taking advantage of their energy concentration in low frequency components. The wavelet transform is one of frequency decomposition, such as the discrete cosine transform or sub-band filtering, and it is also implemented as a filter bank. Wavelet transform with use of spatially localized basis function can reduce several drawbacks in conventional methods. The benifit of wavelet based compression method is described as comparing the transform method to another ones.

• 조명전기설비학회논문지
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• 제24권10호
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• pp.90-98
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• 2010

Microgrid is a small-scale power system composed of distributed generators, energy storage system and loads, and can operate in the grid-connected mode and the islanded mode. This paper presents optimal design procedures for remote microgrid. The design program is based on the economic evaluations including the feasibility study module, optimal combination and allocation of DERs, power network design and the reduction of the GHG emmission. This program which is suggested in this paper shows good performance as a tool of remote microgrid design.

• 대한전기학회논문지
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• 제43권5호
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• pp.739-746
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• 1994

This paper present an efficient methodology to solve the unit commitment problem for large scaled power system which involves various type of generation. We introduce the global optimization approach to coordinate the thermal type, hydro type and pumped storage type generation. To overcome the shortcomings in dynamic programming for thermal unit commitment, an improved heurisitic method using lambda(λ) was proposed, Hydro and pumped type allocation was Solved by analytical approach using λ which exculde undisirable iteration for satisfying the energy usage constraints. The case studies for proposed algorithm are proven by sample system and KEPCO practical system, which produced very resonable both computing requirements and convergency.

• 대한전기학회논문지:전력기술부문A
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• 제50권8호
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• pp.379-387
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• 2001

This paper shows that we can make simple modifications to an existing optimal power flow(OPF) algorithm that minimizes generation costs in order to solve the maximization of social welfare objective of the OPF in a competitive electric power market. We have illustrated the potential for the use of OPF in light of the marked impacts on nodal prices and generation/demand allocation levels among competing suppliers. This paper can provide all market players with the transparent information that ensures sufficient control over producers and consumers in case of economic of secure operation with transmission line outage while maximizing the sum of participants social benefit of participating in the electricity energy market.

• Asian Journal of Innovation and Policy
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• 제7권3호
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• pp.438-456
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• 2018

This study aims to understand the importance of commercialization of research and development projects and examines key factors that allow successful technology transfer and commercialization. Given the characteristics of the railway research project, and assuming that R&D input factors would vary depending on the technology readiness level and the degree of research convergence, this study analyzes the moderating effect of each R&D input factor on technology transfer and commercialization to determine their eventual impact. Through this study, it was found that it was necessary to proceed to technology transfer and commercialization of the national research and development projects via strategic workforce composition and allocation of research funding given the subjects and development goals of R&D projects.