• Proceedings of the SAREK Conference
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• 2004.06a
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• pp.216-216
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• 2004

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.1043-1044
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• 2006

In a packet based wireless system, an adaptive modulation and coding (AMC) scheme is often employed with the use of channel quality information (CQI). However, the AMC can be operated improperly due to delayed CQI, causing performance degradation. In this paper, we consider the use of predicted CQI for the AMC considering the feedback delay and channel characteristics. We also consider the use of a hybrid automatic repeat request scheme with the proposed AMC for further improvement in high mobility environments.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.11 no.17
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• pp.55-65
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• 1988

This article suggests the costs analysis of resumer's view under the stepdown warranty is renewd whenever a failure occurs in the warranty period. And the general warranty policy is showed such as free replacement policy prorata warranty policy, hybrid warranty policy. In this respect case, the cost of consumer is also calculated. In order to study the cost analysis of consumer. "RENEWAL THEORY" is introduced and the cost of consumer is calculated.alculated.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.943-945
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• 1996

In this paper, we present an algorithm that allows tracking of a target using measurements obtained from a sensor with limited resolution. The Interacting Multiple Model (IMM) algorithm has been shown to be one of the most cost-effective estimation schemes for hybrid systems. The approach consists of IMM algorithm combined with a coupled version of the Joint Probabilistic Data Association Filter for the target that splits into two targets.

• Proceedings of the KAIS Fall Conference
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• 2010.05a
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• pp.176-178
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• 2010

본 논문에서는 전통적인 RAID-1 미러링에 기반을 둔 헤테로-미러링이라는 하는 새로운 저장 장치 관리 기법을 제안한다. 헤테로-미러링 기반의 스토리지 관리는 SSD에서 발생 가능한 프리징 현상을 피하기 위한 쓰기-부하 밸런싱과 쓰기 지연 연산을 통하여 RAID-1 처리 성능을 개선한다.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.42-43
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• 2006

We have prepared random, block and graft copolymers with single or dual sensitivities to various stimuli. We have conjugated these polymers to proteins at random lysine sites or at specific sites designed into the protein by genetic engineering. We are also grafting the smart polymers to the surfaces of nanobeads. We are applying these smart conjugates and smart nanobeads in microfluidic devices for various applications, including diagnostics, affinity separations and enzyme bioprocesses. In this talk I will update our work with these interesting hybrid systems.

• Journal of Korean Society of Forest Science
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• v.29 no.1
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• pp.102-114
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• 1976

This experiment was conducted to investigate the percentage of fertile seed in terms of crossabilities and relationships of taxonomic affinities for the ${\times}$ P. rigitaeda of interspecific hybrid, ${\times}$ P. rigida rigitaeda and ${\times}$ P. rigitaeda rigida of backcross hybrids, $F_2$ of ${\times}$ P. rigitaeda and natural hybrid of ${\times}$ P. rigitaeda within Sub-genus Diploxylon of the Genus Pinus. The possibility of establishment of hybrid seed orchard and differentia of hybrids for the purpose of extensive program of reforestation in the future have also been investigated. And, the experimental results obtained are summarized as follows: 1. On the basis of crossabilities as well as on the taxonomic affinities according to the systems of Shaw, Pilger and Duffield, it has been proven that the parental species of those hybrids are of close affinities and range of the fertile hybrid seed production rate was as high as 67-87% in the best hybrid combination (Table 6). 2. Those hybrids seemed to be most promising in the growth perfermance exhibiting 28-80% more volume growth compared to the P. rigida with the statistic significance of 1-5% level (Table 7, 8, 9). And all hybrids exhibit cold hardiness as much as P. rigida except $F_1$ hybrid of ${\times}$ P. rigitaeda and it seems to suggest that the characteristics of cold hardiness were transmitted from the P. rigida. 3. With regard to the anatomical characteristics of needle, the hypoderm is biform in most of the hybrid pines and the characteristics of resin canals are medial in all hybrid. And, the fibrovascular bundles are intermediate of both parent in all hybrid. Therefore it was found to be possible to distinguish the hybrids pines from their parents by the needle characteristics (Table 10). 4. It has been demonstrated that the hybrids pines have a phenolic substance (No. 7) of pale yellow at Rf-0.66, same as P. rigida, but no trace of phenolic substance was observed in the P. taeda. This fact will serve as an important criteria for early identification of hybridity in progeny testing (Table 11). 5. It was found to be possible to distinguish by the starch gel electrophoretic variations banding patterns and staining densities of isoperoxidase in the needles of the hybrids pines from their parents (Fig. 1).

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.3
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• pp.135-148
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• 2003

In this paper we introduce the Internet-based purchase support systems using data mining and case-based reasoning (CBR). Internet Business activity that involves the end user is undergoing a significant revolution. The ability to track users browsing behavior has brought the vendor and end customer's closer than ever before. It is now possible for a vendor to personalize his product message for individual customers at massive scale. Most of former researchers, in this research arena, used data mining techniques to pursue the customer's future behavior and to improve the frequency of repurchase. The area of data mining can be defined as efficiently discovering association rules from large collections of data. However, the basic association rule-based data mining technique was not flexible. If there were no inference rules to track the customer's future behavior, association rule-based data mining systems may not present more information. To resolve this problem, we combined association rule-based data mining with CBR mechanism. CBR is used in reasoning for customer's preference searching and training through the cases. Data mining and CBR-based hybrid purchase support mechanism can reflect both association rule-based logical inference and case-based information reuse. A Web-log data gathered in the real-world Internet shopping mall is given to illustrate the quality of the proposed systems.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.3
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• pp.231-237
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• 2016

Recently, the interest in DC systems to achieve more efficient connection with renewable energy sources, energy storage systems, and DC loads has been growing extensively. DC systems are more advantageous than AC systems because of their low conversion losses. However, the DC-link voltage is variable during operation because of different random effects. This study focuses on DC voltage stabilization applied in stand-alone DC microgrids by means of voltage ranges, power management, and coordination scheme. The quality and stability of the entire system are improved by keeping the voltage within acceptable limits. In terms of optimized control, the maximum power should be tracked from renewable resources during different operating modes of the system. The ESS and VSDG cover the power shortage after all available renewable energy is consumed. Keeping the state of charge of the ESS within the allowed bands is the key role of the control system. Load shedding or power generation curtailment should automatically occur if the maximum tolerable voltage variation is exceeded. PSIM-based simulation results are presented to evaluate the performance of the proposed control measures.

• Journal of Power Electronics
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• v.18 no.2
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• pp.343-355
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• 2018

A wide-voltage-conversion range bidirectional DC-DC converter is proposed in this paper. The topology is comprised of one typical LC energy storage component and a special common grounded asymmetric H-bridge with four active power switches/anti-parallel diodes. The narrow output PWM voltage is generated from the voltage difference between two normal (wider) output PWM voltages from the asymmetric H-bridge with duty cycles close to 0.5. The equivalent switching frequency of the output PWM voltage is double the actual switching frequency, and a wide step-down/step-up ratio range is achieved. A 300W prototype has been constructed to validate the feasibility and effectiveness of the proposed bidirectional converter between the variable low voltage side (24V~48V) and the constant high voltage side (200V). The slave active power switches allow ZVS turn-on and turn-off without requiring any extra hardware. The maximum conversion efficiency is 94.7% in the step-down mode and 93.5% in the step-up mode. Therefore, the proposed bidirectional topology with a common ground is suitable for energy storage systems such as renewable power generation systems and electric vehicles with a hybrid energy source.