• 한국실내디자인학회논문집
• /
• 제22권1호
• /
• pp.265-273
• /
• 2013

The purpose of this study is to analyze the state-of-the-art daylighting design among LEED(Leadership in Energy and Environmental Design) multi-family housing cases and to explore the feasibilities for their applications in domestic housing design. Occupants in multi-family houses are reported to consume more electricity power than those in single houses. That may imply the problems of daylighting design in domestic housing design for multi-family houses have better insulation system and less windows and outside walls than single houses. Therefore two systems, daylight delivery system and daylight control system, are scrutinized for daylighting design with LEED cases. The findings show when windows as a daylight delivery system are combined with overhangs, fins, louvers, fenestration materials, speciality fenestration, or interior controls as a daylight control system, the outcome goes with more energy savings and better facade design. Beside those, lightshelves as a daylight delivery system seem to have potentials in domestic multi-family houses with deep plans and less outside walls. Daylighting designs in domestic multi-family houses need to pursue available options more to achieve the integration of energy and aesthetics values.

• KIEAE Journal
• /
• 제16권1호
• /
• pp.57-65
• /
• 2016

Purpose: The purpose of this study is to analyze the energy performance by applying new technologies for passive and active control. Method: We selected new technologies for passive and active control which are based on formal study by analyzing technology applied to the High-Performance Buildings in various countries. Also, we analyzed energy saving potential for each technologies by breakdown the result of the energy saving rates in detail. Result: For the wall and roof insulating methods, preceding studies showed that up to 21% energy could be saved by improving roof insulation and applying proper outside insulation compared to non-insulation. For the windows and glazing system, preceding studies showed that Low-E glazing system could save up to 11% energy compared to single glazing system. Studies about solar and daylighting controls revealed that effective daylighting dimming control could save 13% of energy compared to uncontrolled situation. Studies on DOAS (Dedicated Outdoor Air System) showed that about 23% energy could be saved compared to standard VAV system. Studies on the active chilled beam showed that about 25% energy could be saved compared to standard VAV system and studies of applying UFAD (Under Floor Air Distribution) could consume 31% less energy than applying overhead system.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
• /
• pp.1001-1004
• /
• 2008

본 연구는 한중환경에서 이중 버블시트를 이용한 단열보온 양생 공법을 슬래브 및 매스 콘크리트에 활용한 결과를 검토한 것이다. 먼저, 이중 버블시트를 적용한 경우 타설 후 2일까지 외기온이 영하$9^{\circ}C$까지 강하하는 경우에도 슬래브콘크리트는 영상 $6^{\circ}C$에서 $10^{\circ}C$이상을 유지하여 초기동해가 방지됨을 알 수 있었고, 매스콘크리트의 경우에는 중심부 최고온도와 표층부 최고온도차이가 $6^{\circ}C$이하로 나타나 내부구속에 의한 수화열 균열은 발생하지 않은 것으로 판단된다. 본 현장에 적용된 이중버블시트를 이용한 단열보온양생 공법은 동절기 영하에서도 안정된 양생온도 관리로 초기동해를 방지할 수 있었고, 소요강도를 확보할 수 있었다. 또한, 가시설의 설치 해체 공정을 줄여 공기단축 효과와 인건비절감등 양생비용의 감소로써 한중콘크리트의 품질확보에 우수한 효과가 있음과 동시에 단열 양생공법의 경제성이 입증되었다.

• 전기학회논문지P
• /
• 제58권2호
• /
• pp.178-183
• /
• 2009

The developed in-flex system completed the wiring work with the plug-in connection. To maintain electrical and mechanical stability, and an insulation between the conductors was strengthened by forming a partition. Moreover, the error according to a bad connection was prevented by separating the inlet from the outlet of the electric trace and thus the quick construction become possible. The metal reinforcing material was added outside the upper case and lower case. The fire-resistance efficiency was maximized in order to minimize a damage by the fire. As to the developed system, we found that it takes shorter time to complete installation than the rigid steel conduit wiring work, and that about 25 % of construction cost was saved because the labor costs decrease due to the shorter construction period of time.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 추계학술대회 논문집 전기물성,응용부문
• /
• pp.25-28
• /
• 2003

Fractal mathematics is being highlighted as a research method for classification of image. But the application of Fractal dimension(FB) has been required the complicated calculation method because of its complex repetition progressing. In this paper, it has been developed the new approach method to express the Fractal Dimension(FB) for aging level calculation and estimation system of outside insulator using special image processing algorithm. As a result after FD testing, the recognized aging estimation of FD has a very characteristics compared to the conventional visual inspection.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 학술대회 논문집 전문대학교육위원
• /
• pp.108-112
• /
• 2000

The electric charge generated by flowing insulation liquid can create hazardous spark in transfer line and receiving tank etc. These electrification has generally been measured by current measurement with a ammeter connected to the receiving tank. This paper reports on the experimental result obtained by this method. As a experimental results: The injected charge value for unit volume increased in the following condition, the edge of the needle electrode was sharp, the number of needle electrode was fewer, the edge of the needle electrode was located close to the inside wall. When the charge density in the charge reducer is constant, electrode current and electrode potential by the charge injection from outside increase with increasing of oil velocity and streaming current. The electrode potential in charge reducer is made maximum value at edge point of reducer inside and minimum value at center line of charge reducer.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 하계학술대회 논문집 E
• /
• pp.2305-2307
• /
• 1999

Partial discharge measurement using a ultrasonic technique allows us to detect degradation of the electrical insulation in a power transformer. However, The ultrasonic measurement studies don't offer a good solution in operating conditions. In this paper, we investigated characteristics of ultrasonic noise caused by a 345kV power transformer under operating conditions. The ultrasonic noises generated by corona in air, vibration of core, pump and fan, etc. An ultrasonic frequency caused by corona in air was appeared 9 and 18[MHz] at the outside wall of the transformer. And a spectra of core vibration was detected below 2.5[kHz]. These spectrum were compared with 20 $\sim$ 200[kHz] of the internal partial discharge in the model transformer.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2003년도 제5회 영호남 학술대회 논문집
• /
• pp.117-120
• /
• 2003

Fractal mathematics is being highlighted as a research method for classification of image. But the application of Fractal dimension(FD) has been required the complicated calculation method because of its complex repetition progressing. In this paper, it has been developed the new approach method to express the Fractal Dimension(FD) for aging level calculation and estimation system of outside insulator using special image processing algorithm. As a result after FD testing, the recognized aging estimation of FD has a very characteristics compared to the conventional visual inspection.

• 한국농공학회논문집
• /
• 제50권4호
• /
• pp.89-97
• /
• 2008

A downdraft gasifier was manufactured for biomass gasification. The gasifier was designed based on the principles of gasification presented in previous studies. The pipes of 25mm diameter were used for both supplying air and discharging producer gas. Wood charcoals were mostly used for fuels. The concentration of CO ranged from 25 to 35%, comparable to the values presented in other studies. The temperature outside wall of the gasifier was measured up to $400^{\circ}C$, indicating a great heat loss. When glass wool was cover over the wall, some parts of wire mesh located in the bottom of the reactor were molten down. There were several modifications that should be made in order to improve its efficiency and obtain more stable continuous gasification, including insulation, reduction in pressure loss, durable bottom meshes, the optimum length of reaction part, and safety.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1998년도 하계학술대회 논문집 A
• /
• pp.319-321
• /
• 1998

Some design technologies of AC traction motor for rolling stocks are presented. AC Traction motors for rolling stocks are operated in worst conditions such as frequent mechanical vibrations, compact design with limited mounting space, severe thermal stress at outside, driven with nonsinusoidal voltage waveform inverters, and so on. Therefore, design procedures must be carefully investigated in the viewpoint of theoritically and practical use. Design procedure contains, the motor size determination, electromagnetic circuit design, insulation system design, vibrations and thermal expansion of rotor bars, temperature rise, as well as output characteristics.