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        검색결과 1,895

        1841.
        2002.06 KCI 등재 서비스 종료(열람 제한)
        컴퓨터 시뮬레이션을 통해서 레이더 타겟들에 대한 레이더 유효면적(RCS)을 측정하고, 그들의 성능특성을 분석하였다. 또한, 상용레이더 리프렉터의 구조적 특징을 검토하였다. 그리고, 수동형 레이더 리프렉터의 최적 설계조건을 선택했다. 연구결과, X-band(λ=3.2cm에서 10λ 크기의 원형 평판으로 구성된 옥타헤데랄 형태의 레이더 리프렉터가 최적 성능을 나타냈다. 그러나, 새로 적용될 2000 SOLAS 규정을 수용하기 위해서는 X-band 와 S-band 모두에 적용하기 위해서 더 큰 크기의 원형평판이 필요하다.
        1844.
        2002.03 KCI 등재 서비스 종료(열람 제한)
        This study intends to classify and analyze the problem of rural villages on the basis of existing ecological and cultural resources. Based on the results of this study, rural villages in Korea can be divided into 4 types - (1) the village abundant in both ecological and cultural resources, (2) the village abundant in only ecological resources, (3) the village abundant in only cultural resources and (4) the village insufficient in two resources. And further, this study found that most ecological resources in rural villages are deteriorated or deteriorating. Even worse, the cultural resources are diminished or diminishing. It is suggested that the ecological and cultural resources need to be taken into account in the process of rural village planning.
        1845.
        2002.03 KCI 등재 서비스 종료(열람 제한)
        예로부터 우리나라와 중국을 비롯한 동양에서는 음양곽을 강정제 및 정력강화제로 사용되어왔다. 본 연구는 흰쥐에게 장기간 음양곽 물 추출물을 공급하고(0.025%,w/v) 노화에 따른 생리적인 변화와 간의 이물질 대사 효소군의 활성도에 미치는 영향을 조사하였다. 흰쥐에 음양곽의 물 추출물 공급으로 특이한 질병은 발견되지 않았으나 24개월에서 간과 신장의 무게는 대조군에 비해 다소 증가하였으며 혈청의 glutamate-oxaloacetate transminase와 glutamate-pyruvate transminase 활성도도 증가하였다 간의 이물질 대사효소 중 cytochrome P450 NADPH-cytochrome P450 reductase, benzphetamine N-demethylase ethoxycoumarine O-deethylase, glutathione S-transferase의 활성도는 두 그룹 모두 노화에 따라 감소하였으며, 음양곽 물 추출물 투여에 의해 감소현상이 악화되었다. 간의 cytochrome B5의 함량과 NADH cytochrome b5 reductase의 활성도도 노화에 따라 감소되었으나 같은 나이에서 두 그룹간의 뚜렷한 차이를 보이지 않았다. 이상의 결과로 보아 흰쥐에 장기간 음양곽 물 추출물을 공급은 노년기에 노화에 따라 감소하는 간의 이물질 대사 기능에 부담을 수도 있다는 것을 암시해 준다.
        1846.
        2002.03 KCI 등재 서비스 종료(열람 제한)
        항공 대잠수함전에 사용되는 방향주파수분석저장 소노부위 (DIFAR Sonobuoy)에 방위정보를 제공하는 플럭스-게이트 콤파스의 위상감응검출 (PSD) 회로 설계와 구현에 관해서 기술하였다. PSD 회로는 쌍동-T RC 회로망을 갖는 능동형 대역필터로 구성하였다. PSD 회로에 대한 성능실험 결과, 대역통과 필터가 지구자장 방향에 비례하는 2Fe의 2차 고조파 신호를 효과적으로 걸러냄을 확인하였다. 그 결과 방위 신호 정보를 획득할 수 있었다.
        1847.
        2001.09 서비스 종료(열람 제한)
        본 논문에서는 국내에서 접근 가능한 몇가지 온라인 3D 게임 엔진에 대해서 조사 비교하였다. 이러한 비교분석은 국제적인 경쟁력을 가지는 국산 3D온라인 게임 엔진개발이라는 과제의 기초자료로 사용될 수 있을 것이다.
        1848.
        2001.08 KCI 등재 서비스 종료(열람 제한)
        A packed bed of volcanic rock was used as deodorizing material to remove hydrogen sulfide(H2S) from air in a laboratory-scale column, and was inoculated with Thiobacillus sp. as H2S oxidizer. The effects of volcanic rock particle size distribution on system pressure drop were examined. Various tests have been conducted to evaluate the effect of H2S inlet concentration and EBCT(Empty Bed Contact Time) on H2S elimination. The pressure drop for particles of size range from 5.6 to 10 ㎜ was 14 ㎜H2O/m at a representative gas velocity of 0.25m/s. Biofilter using scoria and Thiobacillus sp. could get the stable removal efficiencies more than 99.9% under H2S inlet concentrations in the range from 30 to 1,100ppm at a constant gas flow rate of 15.2 ℓ/min. H2S removal efficiencies greater than 99% were observed as long as EBCT was longer than 8sec at the 250ppm of H2S inlet concentration. When EBCT was reduced to 5.5 sec, H2S removal efficiency decreased by about 12 percent. The maximum H2S elimination capacity was determined to be 269g-H2S/㎥·hr.
        1849.
        2001.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Amino acid composition of proteins in Italian millet, Common millet and sorghum were invstigated by HCI hydrolysis method. The optimum condition was obtained by hydrolysis at 110 for 24hr. As major amino acids from protein hydrolyzate, the content of tyosine, arginine and phebylalanine were 7.06%, 6.79% and 6.44%, respectively. The content of glutamic acid in Common millet, Italian millet and Sorghum were 5.73%, 5.64% and 5.46%, respectively. Glycine content was about 2.93% in three samples. Contents of crude protein and pure protein in Italian millet, Common millet and sorghum were determined by micro-kjeldahl method. Crude protein contents were slightly higher than that of pure protein. Protein content of sorghum was higher than those of Italian millet and Common millet. For SDS-PAGE analysis, Italian millet showed more soluble proteins including 50kDa, 30kDa and smaller proteins than other cereals. In particular, Common millet and Sorghum only solubilized proteins less than 15kDa.
        1850.
        2001.06 KCI 등재 서비스 종료(열람 제한)
        이 논문에서는 가상현실 기법을 적용한 항로표지 훈련장치로서, 프로토 타입의 항로표지 시뮬레이션 시스템(AtoNSiS) 개발에 관하여 기술하였다. 항로표지에 대한 시뮬레이션 경험을 향상하기 위하여 3차원으로 측방표지와 방위표지를 제작한 후, IALA-B 방식에 의거한 가상의 3차원 항로를 구축하였다. 이 연구에서 개발한 AtoNSiS는 시뮬레이션 모듈(SM)과 설명 모듈(EM)로 구성하였는데, SM은 다양한 해상환경 변화가 가능한 가상의 항해 공간을 사용하여 IALA-B 시스템을 학습하기 위한 기능을 갖는다. EM은 생성한 3차원 측방 및 방위표지를 이용하여 각 표지들의 상세한 특성을 학습하기 위한 기능을 갖는다. 이러한 AtoNSiS에 대한 설계개념과 개발과정 및 시뮬레이션 실험 등을 나타냈다. 5명의 시청자를 대상으로 실험한 결과 AtoNSiS가 유용함을 알 수 있었다.
        1851.
        2000.09 KCI 등재 서비스 종료(열람 제한)
        약용식물의 기내 (in vitro) 배양에 의한 유용물질의 생산을 위하여 대황 (Rheum undulatum L.)의 유묘 조직 절편에 Agrobacterium rhizogenes A4을 감염시켜 형질전환을 유도하였다. 형질전환된 부정 근인 모상근은 WPM 배지에서 RCM 배지의 3.4배의 성장률 증가를 나타내었으며, 지표 물질인 tannin의 생산량 또한 동일 배지에서 가장 높았다. 배지내 식물성장조절물질의 처리에 의한 모상근의 성장 및 tannin 생산촉진 효과는 식물성장조절물질을 처리하지 않은 대조구에 비해 2 mg/L IAA 처리구와 0.5 mg/L ABA 처리구에서 각기 1.7배의 성장 (0.72 g dry weight/flask)과 1.4배의 tannin (0.67 mg/g fresh weight)의 생산량 증가를 가져왔다. 배지내 탄소원인 sucrose 는 3%와 5%에서 최대성장 (0.54 g dry weight/flask)과 tannin 생산 (0.46 mg/g fresh weight)을 보였으며, chitosan의 농도는 50 mg/L 처리구에서 tannin의 생합성에 영향을 주었다.
        1852.
        2000.08 KCI 등재 서비스 종료(열람 제한)
        The concept of sustainable development in rural area, which is focused on both preservation of nature and human's amenity, has been common paradigm. The purpose of this study is to suggest the development directions for the environmentally friendly rural house. The planning items for developing sustainable rural house were selected through literature survey, case study, and their adaptation evaluation. The establishment of principles and the evaluation of planning items were analyzed by a survey to experts. The results are as follows : 1) It is showed that sustainability evaluation of rural village is rated as above the moderate degree, but rural house is rated as 3.4(average score). Especially, there were lowly evaluated the utility, material, structure and inner environment in rural house. 2) It is revealed that 76.7% of planning items are located in both the upper left and upper right hand quadrant of the action grid, which is drawn by the importance-performance analysis(IPA). And any item is not found in the lower right hand quadrant(Possible Overkill). 3) Two basic principles and eight optional principles we identified by analysis of factor and regression. The rural zone is identified as major effective element for applying planning items into the rural house development. So it is desirable to apply the items differently by the rural zone type. 4) In view of sustainable development, it is desirable for rural village to have about 50 houses, and for rural house to have 155~180 pyung(坪) as lot size, 30% as ratio of building, and 60% as building volume.
        1853.
        2000.06 KCI 등재 서비스 종료(열람 제한)
        The paper deals with the implementation of prototype Ship Simulator system (VRSS) by Virtual Reality techniques with Head Mounted Display (HMD) device. The prototype VRSS was consists of PC-based human sensors, object oriented operating system. In addition, two kinds of databases arranged from Head Related Transfer Functions and 3D object models were used to create 3D sea sound, and to construct virtual world, respectively. Using the prototype system, we carried out some simulation tests for the overtaking situation to prevent collisions at sea, and discussed on the usability of the system. As results from simulations, the prototype VRSS can provide multisensory and interactive display environment. The results gave rise to the user interaction with 3D objects that give realistic reproduction of navigational environments under a given scenario. Thus, we found that the prototype VRSS should be one of the next-generation ship simulation system.
        1854.
        2000.03 서비스 종료(열람 제한)
        In order to cope with the changes of container terminal situation in these days, many simulation studies for container terminal have been accomplished. But previous simulation studies using simulation language have limitations in model representation and difficulties in modeling of large scaled container terminal system. To make these problems better, this paper addresses an object-oriented simulation of container terminal system using a DEVS formalism. The DEVS(Discrete Event System Specification) formalism, developed by Zeigler, supports specification of discrete event system in a hierarchical and modular manner. The formalism provides a mathematical basis for studying discrete event systems with better understood and sounder semantics. In a step of system modeling, a DEVS formalism aims at the exact system modeling that has a basis of semantics and utilizing the object-oriented manner can flexibly cope with the changes of system environment. In this study a model is developed and verified through the simulation of some alternatives.
        1855.
        2000.02 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study was to propose section designs for the ecological improvement of streams in rural villages in Korea. According to the survey about ecological conditions of rural streams of 10 selected rural villages (sep., 1996), the streams could be classified into three divisions(upstream, inner village, downstream), and the average width of streams was 9m, and the height of banks 3.1m. The slopes of basin were 7.33%, 2.67%, 1.39% at upstream, inner village, downstream respectively. The survey about the residents' usage of stream and the preferred activities(jun., 1997) showed that the streams were most frequently used for the supply of agricultural water use(39%), for the washing(15%) and for the recreation and rippling(10%), etc.. Three standard designs were presented for upstream, inner village, and downstream, and three standard sections were made by each designs. For the upstream division, it was designed to be used for the recreational activities in summer and the major stream bank materials were base rock and existing boulders with least artificiality. As the streams in the residential area were expected to be frequent access and used by the residents, most facilities for the streamside activity such as waterfront, water holes, shallows, walk were concentrated in this part with some artificiality. The downstream was designed for the agricultural activities such as water supply, space for the preparation of work and some break during the work.
        1856.
        1999.08 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to investigate the characteristics and suggest the Improvement directions of the facilities in Recreational Forests. This study adopted such various analysis methods as reviewing related documents, surveying the existing sites, and using questionnaire to visitors and managers. The result of this study can be summarized as follows ; 1) The major facilities of Recreational Forests are the lodging, recreation, and sports ones. 2) The primary factor for the visitor's satisfaction is the quality of natural environment, but that for their dissatisfaction is the lack of variety of the available facility. 3) The major problems of facilities in Recreational Forests are their number and design. This study suggests the improvement of accessibility and design of the facilities in the Recreational Forests.
        1858.
        1999.03 KCI 등재 서비스 종료(열람 제한)
        For the purpose of analyzing the influence of the recent environmental changes of container logistics system in container terminal, the simulation model of container logistics system on BCTOC is developed in this paper. The simulation model is accomplished by the AweSim simulation language, and the several data which have been used in simulation gained through spot research and basic statistic analysis using the first half of 1998 electronic data in BCTOC. The results of this study are as follows; (1) In the case of BCTOC, the decreasing of container volumes is observed during the first half of 1998 compare with that of 1997. (2) In the container handling service market, the monopolistic market system in the past rapidly diverts to the competition market system from now. (3) From the simulation results, the improving of container logistics system is observed. (4) Because of these results, BCTOC will come to strengthen customer service and competitive power through starting On-Dock service system and operating the team of customer management in the long term.