• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권1호
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• pp.37-43
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• 2000

In this experimental study we proposed the double dielectric barrier discharge (DDBD) reactor to produce as high an electric field as possible. The experiment are conducted for applied voltage from 15 to 20[kV], $1~4[\ell/min]$ of gas flow rate and 120[Hz] and 240[Hz] of pulse rate. Superposition discharge(SPD) generated in DDBD which combined the surface discharge with the silence discharge was the most effective to reduce the $NO_x$. In the decomposition efficiency per watt, the low pulse rate gave better efficiency than the high pulse rate. However in DeNOx rate, the high pulse rate gave better performance than the low pulse rate. $NO_x$ removal rate and efficiency increased with increasing the applied voltage in all reactors.

• 대한전기학회논문지:전력기술부문A
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• 제49권1호
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• pp.1-5
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• 2000

This paper presents a new algorithm to restore the de-energized loads in electric power distribution systems for restoration by utilizing object-based structure and heuristic rules without branch and feeder overloading. In order to cope with a complex network configuration and frequent breaker switching operations in distribution systems, the component of power system is described as objects and the information of system configuration is constructed by connecting objects each other. Such a strategy is developed mainly based on the object search algorithm to increase computation efficiency. As a result, the proposed system has been implemented to efficiently deal with large distribution systems by reducing computational burden remarkably compared with the conventional methods.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1992년도 추계학술발표강연 및 논문개요집
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• pp.14-14
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• 1992

During the past five years a very successful effort has been made to improve existing and develop new aluminium alloys. The progress achieved has been possible because of the development of new production methods, such as powder metallurgy and spray/deposition. These methods make use of rapid solidification process which alloys compositions other than those achieved by conventional ingot metallurgy. The ingot metallurgy of the 2000 and 7000 series used thus far, as well as the age hardening Al-Li alloys, show several disadvantages caused by the production process. Such problems are primarily coarse intermetallic constituent phases, coarse grains and macrosegregation, resulting in low fracture toughness. The present contribution reports results of an experimental investigation performed on a modern high strength spay deposited aluminium alloy of the Al-Zn-Mg-Cu (7075 and the modified 7150X) type. Results are given in terms of its microstructural characterization by using X-ray diffractomertry and transmission electron microscopic. The mechanical propierties of those alloys in the as-extruded and extruded+aged condition were evaluated by using microhardness Vickers, tensile test and fracture toughness measurements.

• 대한가정학회지
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• 제38권6호
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• pp.1-13
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• 2000

The purpose of the study was to investigate the relationships between parents'attitudes toward emergent literacy and home literacy practices with toddlers and preschoolers. The researcher developed the instrument based on a literature review and on other researchers'(Fitzgerald, Spiegel, & Cunningham, 1991; DeBaryshe & Binder, 1994) questionnaires for parents of toddlers and preschoolers. The researcher did a pilot study to examine the appropriateness of the questionnaires with 68 parents. A total of 274 parents who sent their children to daycare centers participated in this study in central Pennsylvania. To analyze the data for this study, The researcher employed Frequency, Mean, Standard Deviation, Pearson's correlations, Multiple Regression Analysis. Demographic characteristics and parents'attitudes toward emergent literacy which consisted with writing and reading attitudes of literacy were related to home literacy practices for toddlers and preschoolers.. Writing attitudes and verbal participation in reading were the most predicting variables in home literacy practices. The results of this study addressed the importance of the role of belief systems in literacy teaming between parents and children.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2000년도 Proceeding of CIN-KIN Joint Symposium 2000 on M.E.T. Under STCW 78/95 and SINO-KOREA MARITIME CONTACT IN MID-CENTURIES
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• pp.197-200
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• 2000

In this paper, three parts study Zhangbaogao's reaction on the sea trade on Huang Hai in 8-9 centenary, it includes: 1. Mabe a period about the person's sea trade on Huang Hai. 2. Set up the range of sea trade about Tang. Silla and Japan, which the central was korea Peninsula. 3. Extend the termination of the silk Route at eastern, Link-ups the Huang Hai sea trade and silk Route.

• 한국정보처리학회논문지
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• 제7권8호
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• pp.2341-2348
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• 2000

현재 동영상 데이터를 이용한 압축영역에서의 특수효과 구현에 많은 관심이 모여지고 있다. 따라서 본 논문에서는 DCT (Discrete Cosine Transform)압축영역에서 다양한 효과를 위해 최소한의 디코더를 개발하였으며, 이를 이용하여 Wipe, Dissolve, Zoom등의 비디오 효과등을 DCT영역에서 제안하였다. 또한 구현한 디코더와 효과들의 확장성과 이식성이 용이하도록 COM기반의 DirectShow 형식으로 각 모듈을 필터화 하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.136-141
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• 2000

Concrete has been used for many years as a composite material that has excellent mechanical properties and durability for construction. However, concrete ia a poor electrical conductor, especially under dry conditions. Concrete that is excellent in both mechanical and electrical conductivity properties may have important applications in the electrical, electronic, military and construction industry (e.g for de-icing road from snow). The purpose of this investigation is to improve the electrical conductive of cement mortar preparared with graphite as filler. From the test result, as the ratio of graphite/cement increased, fluidity, fluidity and strength decreased but resistivity decreased. The resistivity of electrical conductive cement mortar is effect by water/cement ratio and water content of specimen. From this study, it is enough to assure the use of graphite as a conductive filler for electrical conducive cement mortar.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.605-610
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• 2000

The concrete slab on the foundation may have curling and warping deformations due to temperature gradient of its section. These deformations may change the support conditions of concrete slabs, and cause higher level of stresses tan expected. In this study, partial support conditions de to several temperature gradients are evaluated using FE analysis. Expecially, 3D FE model is adopted to evaluate the partial contact between the slab and the base which is hard to be simulated in 2D FE models. The discrepancies of analysis results increase at high temperature gradients. And it is concluded that 3D FE model can be used to simulate real support and temperature conditions.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.821-826
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• 2000

Reinforced concrete is in general known as high durability construction material under normal environments due to strong alkalinity of cement. Marine concrete specimens in the tidal and the splash zone at seashore have been exposed to cyclic wet and dry saltwaters which cause to accelerate corrosion of reinforcing steel in concrete. If corrosion resistance of concrete gets to weaken de to carbonations and cracks in cover concrete, furthermore, concrete durability rapidly decreases by the corrosion of reinforcement steel embeded in concrete. The objective of this study is to develop appropriate corrosion protection systems of marine concrete so as to enhance the durability of concrete by establishing pertinent cover depth of concrete and by using corrosion inhibitors as concrete admixtures.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 추계학술대회 논문집
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• pp.222-227
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• 2000

"Side scan sonar" using acoustic signal has been developed to survey cable laying, sunken bodie\ulcorner bottom and so on. It use the acoustic signals, which are emitted from two transducer arrays, to get gemetri\ulcorner target area. This system consists of transceiver board, towed body, and deck unit. The transceiver board, w\ulcorner watertight canister of the towed body, controls the transmitting and receiving of 400kHz acoustic signals from \ulcorner After receiving the scattered signals, it processes the filtering, AGF(Automatic Gain Control), TVG(Time Heterodyne. The deck unit is composed of the signal processing part, A/D converter, power supplier, and real\ulcorner And the towed body has been designed to satisfy the optimal hydrodynamic behavior during towing. The de\ulcorner theory of transceiving part and some results from field-experiments will be introduced here.