• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.50
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• pp.127-137
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• 1999

This study is concerned with the loading problems in flexible manufacturing system(FMS). The loading problem in FMS is a complex one, when the number of machine and job is increased. It may be time-consuming and even impossible to achieve an optimal solution about this problem mathematically. Thus, a heuristic method is recommended in order to gain near-optimal solutions in a practically acceptable time. A new loading algorithm is developed with a multi-criterion objective of considering the workload unbalance, and maximizing the machine utilization, throughput for critical resources such as the number of tool slots and the number of working hours in a scheduling period and so on. The results of SAS analysis indicated that true average throughput of proposed heuristic loading statistically exceeds that of Shanker and Srinivasulus loading algorithm at the significance level of 0.1.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.77-79
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• 2003

New cities and industrial complexes are being developed actively because of the government policies aiming population distribution and vitalization of construction industry. To determine the investment amount, number of power lines and substations for stable power supply to newly developed residential and industrial complexes, accurate estimation of power demand is necessary. This paper propose standards for the estimation of power demands for power company and construction company to settle the debates surrounding this issue. Through a survey and analysis of existing areas, new standards that will enable more accurate estimation of power demands in new cities complexes to be developed in the future are established by calculating the average load density, load factor, utilization factor by area, use and building size after dividing the facilities into building type and the areas into the areas planned to be developed and the areas not yet planned to be developed.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2275-2277
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• 1998

This paper presents an algorithmic sensor value validation technique that can systematically explore the embedded sensor redundancies in complex physical systems and maximize their utilization in validating sensor values. The confidency criteria are developed for checking the consistency of sensor relationships called Causal Relations. Development results are applied to a tubular type supercritical pressure type thermal power plant with rated operational data to demonstrate the effectiveness of the proposed technique.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.134-135
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• 2018

Nuclear Power Plant consists of about 1.4 million facilities. and the design standards and design requirements for the continuos utilization and safety of facilities are complexly connected with the facilities. When a design change for facilities or design requirements is occurred at the time of construction or operation, there are a lot of facilities, design requirements, and design bases that are affected by the facilities or design bases being changed. The above design changes are so complex that the existing document-bases design change process is time-consuming and may also cause human error. In this study, we developed a design requirement taxonomy that can be applied to the data-centric design bases document that can improve it. To do this, we analyze the design elements from the highest level to the lowest level applied to the nuclear power plant, and classify the design elements according to the characteristics of the design elements.

• Journal of Korean Association for Spatial Structures
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• v.17 no.1
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• pp.85-92
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• 2017

The objective of this paper is to suggest structural design for the long-life housing apartment complex to save the construction cost. The key is to use unavailable underground space due to bearing walls or bad configuration of columns in apartments as the parking space. Therefore, the structural plan of apartment buildings considering the parking section in the underground should be designed. After analytical resutls of three cases, it is significant effect in saving construction cost.

• Structural Engineering and Mechanics
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• v.56 no.3
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• pp.423-442
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• 2015

This study examines the wavelet transform for output-only system identification of ambient excited engineering structures with emphasis on its utilization for modal parameter estimation of high-order and closely-spaced modes. Sophisticated time-frequency resolution analysis has been carried out by employing the modified complex Morlet wavelet function for better adaption and flexibility of the time-frequency resolution to extract two closely-spaced frequencies. Furthermore, bandwidth refinement techniques such as a bandwidth resolution adaptation, a broadband filtering technique and a narrowband filtering one have been proposed in the study for the special treatments of high-order and closely-spaced modal parameter estimation. Ambient responses of a 5-story steel frame building have been used in the numerical example, using the proposed bandwidth refinement techniques, for estimating the modal parameters of the high-order and closely-spaced modes. The first five natural frequencies and damping ratios of the structure have been estimated; furthermore, the comparison among the various proposed bandwidth refinement techniques has also been examined.

• Korean Journal of Microbiology
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• v.25 no.1
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• pp.80-85
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• 1987

The aim of the present studies was to analyze the physiological background of ethanol inhibition in Zumomonas mobilis. The experiments were carried out with a number of continuous culture to give steady state concentration of ethanol. The domposition of fatty acids in the cells obtained from various conditions was analyzed and cell viability was also estimated. As results, it was found that vaccenic acid was the mafor fatty acid in the cell of Z. mobilis and the concentration was changed apparently to increase as increasing the concentration of ethanol produced from substrate utilization. Finally it was observed also that cell viability was decreased remarkably at the elevated ethanol concentration. Those changes might play important roles in the ethanol fermentation to give more complex phenomena observed at high concentration of ethanol.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.4
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• pp.823-832
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• 1997

As enterprises use ATM networks for their private networks and as these private networks use public ATM networks for wide area communication, the need for the customers to be able to manage both private and public networks. Currently, some standardization work is being done towards providing this capability to customers. In this paper, we propose a new customer network management (CNM) system architecture for the management of both ATM a private network and a public network in a uniform way. The particular features of the proposed architecture lies in the efficient support of the complex hierarchial TMN manager-agent relationships at M3 and M4 interfaces, and the support of SNMP and CMIP integration which is necessary for the implementation of a CNM system. The TMN hierarchical many-to-many manager-agent relationships are realized by the utilization of CORBA-Based SMK (Shared Management Knowledge) implementation. We have also implemented the prototype of a ATM CNM system, and measures the performance for the demonstration of the suitability of the proposed architecture.

• Journal of Power Electronics
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• v.15 no.4
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• pp.929-938
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• 2015

Maximum power point tracking (MPPT) and battery charging control are two important functions for a solar battery charger. The former improves utilization of the available solar energy, while the latter ensures a prolonged battery life. Nevertheless, complete implementation of both functions can be complex and costly, especially for low voltage application such as standalone street lamps. In this paper, the operation of a solar battery charger for standalone street light systems is investigated. Using only one voltage sensor, the solar charger is able to operate in both MPPT and constant voltage (CV) charging mode, hence providing high performance at a low cost. Using a lab prototype and a solar simulator, the operation of the charger system is demonstrated and its performance under varying irradiance is validated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.510-511
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• 2005

Several iridium based complexes were investigated as blue phosphorescent dopants. They are achieved about 100 % quantum efficiencies due to utilization of both singlet and triplet excitons in the radiative processes. We have fabricated phosphorescent OLED with 8 % Ir$(ppz)_3$ as a triplet emissive dopnat in diverse host materials. In this study, the CBP obtained the luminance efficiency of 0.20 cd/A adapts to the host material. Furthermore, we synthesize metalorganic phosphor complexs based on Ir heavy metal with different ligands as to $Ir(ppz)_2acac$, $(Im)_2Ir(acac)$, $(Im-R)_2Ir(acac)$.