• Journal of the Korean Institute of Telematics and Electronics C
• /
• v.34C no.3
• /
• pp.23-36
• /
• 1997

In tis paper, sthe new data model for the hardware implementation of lempel-ziv compression algorithm was proposed. Traditional model generates the codeword which consists of 3 bytes, the last symbol, the position and the matched length. MSB (most significant bit) of the last symbol is the comparession flag and the remaining seven bits represent the character. We confined the value of the matched length to 128 instead of 256, which can be coded with seven bits only. In the proposed model, the codeword consists of 2 bytes, the merged symbol and the position. MSB of the merged symbol is the comression flag. The remaining seven bits represent the character or the matched length according to the value of the compression flag. The proposed model reduces the compression ratio by 5% compared with the traditional model. The proposed model can be adopted to the existing hardware architectures. The incremental factors of the compression ratio are also analyzed in this paper.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.04a
• /
• pp.729-737
• /
• 1996

Laminated composite plates have been applied to aircraft structures because their properties are superior to the conventional materials and the laminates have anisortropic elastic properties. However, it tis diffcult to determine stacking structures using actual design variables for the lack of searching capability of existing optimization technique. GA(generic algorithms) are robust search algorithms based on the mechanics of natural selection and natural genetics. Therefore, this study presents an application of IGA to stiffness and weight optimization design and gives the various stacking structures suitable to constraint conditions.

• Journal of Welding and Joining
• /
• v.5 no.4
• /
• pp.28-35
• /
• 1987

The feasibility of underwater wet arc welding process is experimentally investigated by using high titanium oxide type electrodes and TMCP steel plates as base metal. It is assertained the tis process may be put to practical use. Main results are summarized as follows; (1) Sound underwater weld can be obtained by skilled welding operator, if proper welding conditions are selected. (2) In underwater wet arc welding process, the mechanical properties of HAZ are depend upon welding condition and the optimum welding condition can obtained. (3) The maximum hardness in the HAZ of TMCP steel plates is increased significantly in this welding process.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.32A no.12
• /
• pp.122-129
• /
• 1995

The most important feature of a-Si TFT is dense localized states such as dangling bonds which exist in tis bandgap. Electrons trapped by localized states dominate the potential distribution in the active a-Si region ,and influence the performance of a-Si TFT. In this paper, we describe the electrical characteristics of a-Si TFT with respect to trap distribution within bandgap, electron mobility and interface states using 2-Dimensional device simulator and compare the result of simulation with measurements. Using the mixed-mode simulator, we can predict the potential variation of pixel which causes residual image problem during the turn-off of a-Si TFT driving circuit. Therefore it is possible to consider trade-off between potential variation of pixel and turn-on current of a-Si TFT for the optimized driving circuit.

• Journal of the Korean Institute of Telematics and Electronics C
• /
• v.34C no.8
• /
• pp.1-7
• /
• 1997

In tis paper, w eproposed a modeling for direct-sequence spread communication base band modem in RT-level VHDL and implemented in a one-chip VLSI and tested. The transmitter modulates with DQPSK modulation method and spreads a modulated signal with 32-bit PN code into 1.152MHz. The receiver de-spreads a signal using 32-tap matched filter and recovers with DQPSK demodulation method. The digital frequency synthesizer generates the sine signal and the cosine signal of 2.304MHz with ROM tables in the size of 7$\^$*/256 and 6$\^$*/256, respectively. The implemented VLSI has been verified a BER with 10$\^$-4/ at E$\_$b//N$\_$o/ of 13dB with a SPW fixed design model and fabricated in the 0.8.mu.m KG6423 gate array with a VHDL model.

• The Journal of the Korean dental association
• /
• v.34 no.3 s.322
• /
• pp.215-222
• /
• 1996

Ridge expansion osteotomy(REO) procedure is used to widen the narrow ridge in locations that are too thin to permit the use of standard implant drills. The objective of this technique is to maintain, if possible, all of the existing maxillary bone by pushing the bone aside with minimal trauma. The author has used tis procedure on five patients who had narrow ridge in their soft maxillary bone. Fifteen implants were placed in sites needing ridge expansion using REO. The satisfactory results were obtained. The REO procedure is thought to be a safer and more conservative method of widening a narrow ridge. And this procedure is heatless, offers excellent tactile sensitivity, control, visibility, and takes advantage of available bone.

• Archives of Pharmacal Research
• /
• v.17 no.2
• /
• pp.66-70
• /
• 1994

The condensation reactions of hippuric acid and tis furyl derivative with salicyladehydes or that of salicylhippuric acid analogues with furadehyde led to the comesponding oxazoles. These wre subsequently treated with hydrazine hydrate, hydroxylamine or subjected to alkaline hydrolysis to yield new o-hydroxyaryl or salicyl containing derivatives. 5-Substituted salicylanilides were treated with piperidine and formaldehyde in a Mannich type reaction affording the corresponding 3-(N-piperidinomethyl) salicylanilides. It was noticed that the presence of an electron donating group in in position 3 in the salicylanilide moiety decrease the mollusicidal activity.

• Journal of the Korea Society of Computer and Information
• /
• v.20 no.9
• /
• pp.113-119
• /
• 2015

The purpose of tis study is to analyze the effects of job embeddedness on job burnout related with social worker's turnover. This study suggests some implications for decreasing the level of social worker's job burnout. In this study, embeddedness is composed of three sub-variables like fit, links, and sacrifice. Job burnout is also composed of emotional exhaustion, depersonalization, and decrease of personal accomplishment. Thereafter, research model is established, and study hypothesis is tested through the survey. As a result, it showed that the components of job embeddedness have significant effects on the components of job burnout. Based on the result of this empirical analysis, this study suggested some theoretical and political implications.

• Journal of the Korean Society for information Management
• /
• v.13 no.1
• /
• pp.103-117
• /
• 1996

The purpose of this study is to identify how users react with the search options and bibliographic information during search reformulation on the online catalog. Two online catalogs(N0TIS system and Dynix system) were selected and undergraduate students were recruited as the participants for this study. The study shows that the search options and bibliographic information affected the type of the query reformulation and the re-choice of the search options during search.

• Journal of Institute of Control, Robotics and Systems
• /
• v.7 no.2
• /
• pp.131-137
• /
• 2001

Traditional genetic algorithms, though robust, are generally not the most successful optimization algorithm on only particular domian. Hybridizing a genetic algorithm with other algorithms can produce better performance than both the genetic algorithm and the other algorithms. This paper describes the application of random signal-based learning to a genetic algorithm in order to get well tuned fuzzy rules. The key of tis approach is to adjust both the width and the center of membership functions so that the tuned rule-based fuzzy controller can generate the desired performance. The effectiveness of the proposed algorithm is verified by computer simulation.