http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
개별검색 DB통합검색이 안되는 DB는 DB아이콘을 클릭하여 이용하실 수 있습니다.
통계정보 및 조사
예술 / 패션
<해외전자자료 이용권한 안내>
- 이용 대상 : RISS의 모든 해외전자자료는 교수, 강사, 대학(원)생, 연구원, 대학직원에 한하여(로그인 필수) 이용 가능
- 구독대학 소속 이용자: RISS 해외전자자료 통합검색 및 등록된 대학IP 대역 내에서 24시간 무료 이용
- 미구독대학 소속 이용자: RISS 해외전자자료 통합검색을 통한 오후 4시~익일 오전 9시 무료 이용
※ 단, EBSCO ASC/BSC(오후 5시~익일 오전 9시 무료 이용)
5종의 주택난방식에 따른(1) 실내온도 기준, (2)실내 온도변화, (3)각실 온도간의 상호작용에 대한 상황을 동계와 하계별로 실제조사 측정한 자료를 중심으로 비교 분석검토하였다. 동계간(1), (2), (3)조건은 난방 방식에 따라 크게 상이함이 판명되었다. 동계간 비교적 저온을 유지하는 재래식 난방방식(SOFA·SOFB)은 외기온의 변화에 따른 실내온도의 변화가 현저하며 축열식 난방식(OSHD, UFWE)은 변화가 적다. (3)조건은 일반적으로 높은 온도 분포를 보여주는 난방방식에서는 상호 실내간온도 작용이 원활하나, 실의 공간적 배치에 따라 온도의 상호작용이 크게 상이함을 알 수 있었다.
Sulfonated polystyrene-divinylbenzene (PS-DVB) copolymer membranes were prepared using different diluents and varying diluent volume and DVB contents. All membranes were reinforced with Teviron (PVC) cloth. Three different diluents (toluene, cyclohexane, cyclohexanol) were used in the polymerization system. The membranes have been characterized by their swelling ratio, water content, ion-exchange capacity and mechanical strength. The volume as well as kind of diluents, and DVB content influenced these properties. As a result, water content and ion-exchange capacity decreased with increasing DVB concentration. Among diluents, cyclohexanol was the most efficient for building up the highest water content and ion-exchange capacity.
Autonomous action, which corresponds actively to the change of conditions in complicated circumstances, is a fundamental function equired to an intelligent mobile robot. To develop a control system for a mobile robot having such ability adaptable to the circumstances, it is necessary to establish the self-tracing technology which enabies the mobile robot to locate itself in its surrounding circumstances and manipulate its driving part with fiexibility. In this paper, to enable the mobile robot to find its location, the method of representing the route, necessary to make the route map which is used to move from the current position to the destination, is suggested. But the flexible navigation control is required for the mobile robot to navigate along the route map. So fuzzy control algorithm is suggested as navigation control algorithm. Such basic operations in navigation of the mobile robot as going straight, turning, avoiding obstacles are tested.
The transport characteristics of alkali metal ions, ?? and ??, through a cation exchange membrane was investigated. The membrane used in this experiment was ?? type sulfonated polystyrene-co-divinylbenzene membrane (K-102, Asahi Kasei Co.). The initial flux of the ion was increased with the increase of both ?? ion concentration and temperature. In this experimental range (pH 0.5∼3.0, temperature 15∼60℃), the initial flux of ?? was found to be from ?? to ?? and that of ?? from ??, ??. The membrane was selective for ?? and the flux ratio of ?? to ?? was about 1.10.
An alumina monlith was prepared from Al-sec-butoxide solution by the sol-gel method. The effects of peptizing agents, DCCA, drying conditions, and heat-treatments on characteristics of alumina monolithic films were investigated. The clear sol of boehmite could be effectively obtained using acetyl chloride or nitric acid as a peptizing agent, and the crack-free alumina gel was also prepared by the careful control of drying rates. The addition of various DCCA used in this study for controlling drying rates, however, caused an occurrene of crack in the gel during drying and final heat-treating. It was found that the alumina monolith had a high surface area (43㎡/g) and a strong hygroscopic property, and that purity of α-Al₂O₃, heat-treated at 1250℃ was 99.87%.
Hydrolized products were prepared from Si- and Al- alkoxides as a starting material. By using the carbothermal reduction method, Sialon-SiC composite powders were obtained from hydrolized products in N₂/H₂mixed atmosphere at 1350℃. The synthesized powders were characterized by XRD, TEM and size analysis, and they were hot-press sintered at 1750℃ for 90 min under 30 MPa in N₂atmosphere with 8 wt% Y₂O₃as a sintering aid. The Characters of synthesized powders and mechanical properties of Sialon-SiC composite ceramic were as followed. The hydrolized products prepared from mixed Si and Al alkoxides were amorphous. In Sialon-SiC composite powders obtained by using the carbothermal reduction, SiC contents were increased as H₂ratio in N₂/H₂atmosphere was increased. The highest values of the mechanical properties obtained in this study were as followed: M.O.R., ?? and ?? of Sialon-SiC composite ceramic were 780 MPa (SiC contents: 25 wt%), ??(SiC contents: 55 wt%), 18.8 GPa(SiC contents: 80 wt%), respectively.
4.82 wt% AIN and 2.95 wt% Y₂O₃were added to Si₃N₄as sintering agents in order to have α-Sialon composition of X=0.15 and monoclinic ZrO₂between 0 to 10 wt% was admixed with Si₃N₄. Si₃N₄based ceramics were fabricated by hot-pressing at 1750℃ for 90 min under 30 MPa in argon and nitrogen atmospheres Effects of sintering atmospheres and addition of ZrO₂on mechanical proporties of Si₃N₄based ceramics were investigated. As ZrO₂content increased, the fraction of α-Sialon tended to decrease and the amount of cubic ZrO₂increased because Y₂O₃acted as the stabilizer of ZrO₂. The sintering atmospheres didn't affect on the sintering behavior and the product phases in hot-pressing of Si₃N₄. Bending strength increased when ZrO₂was added up to 3 wt%. Hardness showed tendency to decrease with ZrO₂content. ZrO₂didn't contribute to the increase of fracture toughness because stabilized cubic ZrO₂was produced by the added Y₂O₃.
Alpha alumina powder with fine particle size and narrow particle size distribution was prepared by precipitation method using Al₂(SO₄)₃·18H₂O as a starting material. The alpha alumina powder was prepared by calcining aluminum hydroxide which was formed under various pH values. The sinterability of alpha alumina powder and the effect of MaO on the sinterability of alpha alumina powder were investigated. The sinterability of alpha alumina powder was the order of pH=10=pH=11>pH=7=pH=9 and alpha alumina obtained from boehmite which was prepared by precipitation method reached to 97.5% of theoretcal density by the pressureless sintering. The effect of MaO on volume shrinkage of alumina was very slight in the initial sintering stage but remarkable in the final sintering stage. It was also found that MgO controlled effectively the grain growth of alumina.
In this study, the stabilization process of solid wastes was investigated related to bio-gas production, using lysimeters filled with municipal wastes contained a high percentage of organic refuse. The lysimeters were operated four types; continual through-flushing with water, leachate recirculation, leachate recirculation with pH control, and in-situ condition. Also each type was consisted of three lysimeters and operated with detention time 3 days, 6 days, 12 days, respectively. As the results, inorganic material, ??, was decreased by physical dilution and organic materials such as COD, VS were decreased by biological activity as well as dilution. The ratio of VS to TS was decreased proportionately in the course of time. Leachate recirculation was shortening the period of stabilization by accelerating bio-degradation of organic wastes. And the reactors operated leachate recirculation with pH control accelerated the rate of gas production.
The object of this study is to analyze the dynamic characteristic of lateral damper for the railway vehicle. The vibration characteristics are studied from eigenvalue analysis for critical velocity, and frequency analysis for the effects of the damper. Critical velocity of the model passenger car is found to be a) 20 m/s for damping force of 0 kg s/m, b) 64 m/s for damping force of 1,500 kg s/m, c) 60∼74 m/s for damping force of 730∼2,500 kg s/m. In high speed running, damping force should be decreased for high critical velocity. Lateral damping force should be greater than 730 kg s/m for stable running.