• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.8
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• pp.482-492
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• 2002

This paper deals with overvoltage stresses in the field circuit of synchronous machine connected to HVDC terminal. A load rejection of the HVDC may cause generator in the station to become self-excited, resulting in a severe system overvoltage. This paper shows that violent field current oscillations can be produced by resonance between the machine inductance and the terminal capacitance. As most conventional excitation system do not allow reverses current, new topology of excitation system to allow reverse current is proposed. the proposed system can limit the rate of rise of terminal voltage during conditions of self excitation. Apart from these simulations, the nature(Magnitude and frequency) of the field transient state is explained mathematically. Finally, the EMTDC program is used for the simulation studies.

• Journal of Korean Library and Information Science Society
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• v.22
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• pp.373-401
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• 1995

This study aims to improve subject retrieval by constructing the hypertext-based thesaurus to provide a browsing interface to a thesaurus. The experimental system used IBM 486 DXII as a hardware, C++ language as a programming language and Hangul Window 3.1 version as a user interface. The results of this study are summarized as follows : (1) The experimental hypertext-based thesaurus can be used as an efficient search aid for query formulation for the retrieval of bibliographic information. (2) The initial access to the hypertext-based thesaurus is via a keyword index. This index is consist of all the words used to form thesaurus terms, whether descriptors or nondescriptors. (3) Hypertext-based thesaurus allow bookmark button and history button to alleviating the problem of disorientation. (4) This system allow an end-user to view a rich variety of inter-term relationships and a complete conceptus of associations through the information space in a nonsequential manner.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.147-151
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• 1991

In this paper a time-optimal path planning scheme for the multiple robot manipulators will be proposed by using hopfield neural network. The time-optimal path planning, which can allow multiple robot system to perform the demanded tasks with a minimum execution time and collision avoidance, may be of consequence to improve the productivity. But most of the methods proposed till now suffers from a significant computational burden and thus limits the on-line application. One way to avoid such a difficulty is to rearrange the problem as MTSP(Multiple Travelling Salesmen Problem) and then apply the Hopfield network technique, which can allow the parallel computation, to the minimum time problem. This paper proposes an approach for solving the time-optimal path planning of the multiple robots by using Hopfield neural network. The effectiveness of the proposed method is demonstrated by computer simulation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.4
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• pp.297-306
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• 2007

Distraction osteogenesis was pioneered by Ilizarov in the treatment of injured extremities. Its subsequent application to Oral and Maxillofacial Surgery has opened a new chapter in the treatment of facial deformity. Careful monitoring of the period of distraction and consolidation of the callus is important and has been well described. Complications, such as infection, haematoma and premature ossification, are difficult to diagnose and can compromise the outcome after the surgery. Too slow rate of distraction results in premature fusion of cortices and too rapid information of bone 'cyst' within the callus distraction. I experienced 2 patients of congenital unilateral mandibular hypoplasia, so called Hemifacial Microsomia. After distraction surgery, I evaluated callus formation of mandibular distraction with Ultrasound Sonography during distraction and consolidation period. Plain radiography, although it enables accurate measurement of the distraction gap, did not give sufficient detail to allow assessment of early stages of bone formation, But, ultrasound monitoring could enable continuous monitoring of the distraction gap without exposure to ionizing radiation and allow detection of fine detail, which may influence manipulation of the callus.

• Proceedings of the KSPS conference
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• 2003.10a
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• pp.69-72
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• 2003

In this paper, we investigate various factors that are relevant to design and implementation of an integrated management system for various speech corpora. The purpose of this paper is to manage an integrated management system for various kinds of speech corpora necessary for speech research and speech corpora consrtructed in different data formats. In addition, ways are considered to allow users to search with effect for speech corpora that meet various conditions which they want, and to allow them to add with ease corpora that are constructed newly. In order to achieve this goal, we design a global schema for an integrated management of new additional information without changing old speech corpora, and construct a web-based integrated management system based on the scheme that can be accessed without any temporal and spatial restrictions. And we show the steps by which these can be implemented, and describe related future study topics, examining the system.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.698-702
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• 1992

In this paper, Micro-Genetic algorithms(.mu.-GAs) is proposed on a minimum-time path planning for robot manipulator, which is a kind of optimization algorithm. The minimum-time path planning, which can allow the robot system to perform the demanded tasks with a minimum execution time, may be of consequence to improve the productivity. But most of the methods proposed till now suffers from a significant computation burden and can't often find the optimal values. One way to overcome such difficulties is to apply the Micro-Genetic Algorithms, which can allow to find the optimal values, to the minimum-time problem. This paper propose an approach for solving the minimum-time path planning by using Micro-Genetic Algorithms. The effectiveness of the proposed method is demonstrated using the 2 d.o.f plannar Robot manipulator.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.4
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• pp.40-47
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• 1994

In this paper, Micro-Genetic algorithms($\mu$-GAs) is proposed on a minimum-time path planning for robot manipulator. which is a kind of optimization algorithm. The minimum-time path planning, which can allow the robot system to perform the demanded tasks with a minimum execution time, may be of consequence to improve the productivity. But most of the methods proposed till now suffers from a significant computation burden and can`t often find the optimaul values. One way to overcome such difficulties is to apply the Micro-Genetic Algorithms, which can allow to find the optimul values, to the minimum-time problem. This paper propose an approach for solving the minimum-time path planning by using Micro-Genetic Algorithms. The effectiveness of the proposed method is demonstrated using the 2 d.o.f plannar Robot manipulator.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.4
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• pp.9-17
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• 1994

The incremental parsing techniques are essential part of language-based environment which allow incremental construction of programs, as reparsing of modified part of the program alone enhances the system performance. A number of methods and algorithms have been proposed for incremental parsing and for the construction of incremental parsers. The purpose of this paper is to review the earlier incremental parsing algorithms which are too expensive in both time and space, and to present an efficient incremental LR parsing algorithm which is more efficient than the previous ones. In this paper, we generate automatically an extended LR parsing tables which allow the nonterminal symbols as well as terminal symbols for the input, and apply them to our efficient incremental LR parsing algorithm. Using these extended LR parsing tables. we suggest several methods to reduce its memory spaces and parsing steps as well. The algorithms described here were implemented in C language and YACC on a SUN UNIX OS, and were tested with several grammars and strings.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.27-27
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• 2017

The rapid growth of world population, reduction of cultivated areas for crop production, and detrimental effects of pests, diseases, and climate changes have required to breed new rice cultivars with high yield, accepted quality, but strong resistance to abiotic and biotic stresses. However, traditional breeding needs much time to breed a new cultivar, whereas the successful use of molecular breeding is still questionable. We have developed a novel mutation which allow to cross many rice cultivars together with low segregation, that allow to breed a new cultivar in only several cropping. The mechanism has been unknown, but we suggest that gene linkage may play a crucial role, of which the semi dwarf gene might be the center gene for gene linkage occurrence. The phenomenon of this possible gene linkage is contrary to Mendel rules, but it is promising to breed new rice cultivars, of which, the most elite genes in rice might be able to gather in a targeted rice variety.

• Language and Information
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• v.14 no.1
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• pp.49-65
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• 2010

It has been widely accepted that English object extraposition can be easily accounted for. However, recent research exhibits the fact that various cases of English object extraposition lead to many empirical and theoretical problems in generative grammar. To account for such cases, the previous lexical constraint-based analyses including Kim & Sag (2006, 2007) and Kim (2008) attempt to give an explanation on the phenomenon. They, however, seem to be unsuccessful in providing an appropriate analysis of object extraposition, mainly due to the mistaken data generalizations. Unlike the previous analyses, we claim that all verbs selecting CP objects allow object extraposition and propose a unified constraint-based analysis for the various cases of the construction. Further, it is shown that as a consequence, this analysis of object extraposition can be naturally extended to subject extraposition. Hence, this unified analysis enables us to further suggest that all verbs selecting CP allow subject and object extraposition in English.