• 한국식품영양학회지
• /
• 제4권1호
• /
• pp.81-90
• /
• 1991

This study was conducted a comprehensive survey of 39 elementary schools operating school lunch program in Seoul area. The purpose of this study was to investigate the realities of school lunch program. This method of the research was based on the interview survey with dietitian working at each school with prepared questionnaire. The survey was conducted for 16 days from Dec. 5 to Dec. 20., 1990. The results of this study were as follows ; (1) The average numbers of children supplied with food were 1,244 for each school. It was about 44.3Bb of the students enrolled in the school. The average feeding cost was 738 won per a child for a day. (2) Only one school was operating nutritional education as a regular educational program, and others were operating nutritional education off and on. (3) All nutrient intake except energy were higher than the RDA for school lunch program. (4) The ratio of animal food was 46.2%, and that of vegetable food was 53.8%. (5) The ratio of schools without sterilizer cabinet came to 56.4%, and that of schools without warmer was 97.4%. (6) The facilities for drainage, lighting, ventilation, anti-rat of a cookery were comparatively good.

• 한국마이크로전자및패키징학회:학술대회논문집
• /
• 한국마이크로전자및패키징학회 2001년도 Proceedings of 6th International Joint Symposium on Microeletronics and Packaging
• /
• pp.57-65
• /
• 2001

Economical consumption of energy, longer life of lamps, higher lighting comfort and new aesthetic of illumination is subject of numerous research and development works. The halogen lamps are an example of positive solution some of above mentioned problems. The electronic transformers are more frequent used for their supply. In comparison with conventional transformers they have less weight, less volume and 60% less power tosses. Their advantages are particular visible, when the hybrid technique is applied. The paper presents the results of engineering research and development works carried out ill Private Institute of Electronic Engineering, in R. & D. Center for Hybrid Microelectronics and Resistors and in Technical School of Communications in Krakow, in the field of the design and exploitation tests of hybrid converters 220V AC /12V DC (electronic transformers) and electronic ballasts destined for the supply of halogen lamps 20W to 150W and fluorescent lamps respectively. To perform the converters, thick film technology and surface mount technology were used. For the protection of converter electronic circuit the thick film temperature sensor and transistors were applied. Moreover the paper presents the base application circuits of elaborated converters, their technical parameters and exploitation results. The development perspectives of hybrid domain of hybrid circuits are also discussed.

• 한국인터넷방송통신학회논문지
• /
• 제12권1호
• /
• pp.181-187
• /
• 2012

LED는 빛을 내는 반도체 이다. 최근 친환경적 산업이 발전함에 따라 LED조명의 연구가 활발하게 진행되어 가고 있다. 특히 LED를 이용한 통신기법인 LED 통신에 대한 활발한 연구가 진행 중이다. 본 논문에서는 LED 통신을 이용한 PC-PC 전송시스템을 구현하였다. LED를 이용한 송신부 회로구성 및 PD와 OP-Amp를 이용한 수신부 회로를 구성하였다. 실험은 다음처럼 진행되었다. 송 수신부 양 끝단에 컴퓨터를 연결한 다음, 텍스트 전송프로그램을 이용하여 텍스트를 전송하였다. 이때 보드 레이트(baud rate), LED 색깔, 전송거리 등 다양한 변화를 주면서 실험을 진행하였다.

• 한국전기전자재료학회논문지
• /
• 제28권4호
• /
• pp.271-275
• /
• 2015

The floodlighting assists the pilot in taxiing the aircraft into and out of the final parking position and provide lighting suitable for passenger to embark and debark and for personnel to load and unload cargo. It is composed of sodium lamps which is consuming high energy. It needs to develop a dedicated LED lamp to replace the existing lamps. In this paper, We propose a suitable asymmetric angle of LED lamps to avoid a pilot's glare and to meet the standard illumination. For this, we analyze asymmetric angle of sodium lamps which are using in airport and confirm whether the illumination distribution and glare index meet the relating standards by using simulation method. Also, we study the needs of asymmetric characteristics of LED ramp by simulating the LED lamps with and without asymmetric characteristics of ramp respectively. With the simulation result, finally we propose the best asymmetric angle of LED lamp to meet the average illumination standard, and avoid a pilot's glare.

• 국제초고층학회논문집
• /
• 제6권4호
• /
• pp.297-300
• /
• 2017

Employers are realizing that workplaces have an immense impact on productivity. And, because people typically represent about 90% of a company's costs, even a slight improvement in productivity hits the bottom-line in a very big way. The focus is shifting away from saving money by reducing space needs or cutting energy requirements, and moving toward making the workplace friendlier and healthier. What is a healthy workplace, exactly? The answer should be clear by now. Mountains of research have expounded on this very topic, and then news outlets cover the latest discoveres ad infinitum. The problem is, research is rather dense, while the news isn't comprehensive. Office managers trying to improve workplace wellness want neither a 55-page report nor a half dozen articles to convince their landlord that their space can do better. Recognizing this gap, Harvard researchers have released a concise-yet-complete list of healthy building features. Here, we're sharing these nine features with a few insights of our own on the value of being healthy and productive. Find out: ${\bullet}$ What makes a healthy building and why is it so important ${\bullet}$ How to improve the health of your own office ${\bullet}$ What happens for your people and your bottom line when you make health a priority.

• Journal of the Optical Society of Korea
• /
• 제16권3호
• /
• pp.247-255
• /
• 2012

Daylighting has a very effective role in reducing power consumption and improving indoor environments in office buildings. Previously, it was not under consideration as a major source of renewable energy due to poor reliability in the design. Optical fiber as a transmission medium in the daylighting system demands uniform distribution of light to solve cost, heat, and efficiency issues. Therefore, this study focuses on the uniform distribution of sunlight through the fiber bundle and to the interior of the building. To this end, two efficient approaches for the fiber-based daylighting system are presented. The first approach consists of a parabolic mirror, and the second approach contains a Fresnel lens. Sunlight is captured, guided, and distributed through the concentrator, optical fibers, and lenses, respectively. At the capturing stage, uniform illumination solves the heat problem, which has critical importance in making the system cost-effective by introducing plastic optical fibers. The efficiency of the system is increased by collimated light, which helps to insert maximum light into the optical fibers. Furthermore, we find that the hybrid system of combining sunlight and light emitting diode light gives better illumination levels than that of traditional lighting systems. Simulation and experimental results have shown that the efficiency of the system is better than previous fiber-based daylighting systems.

• 한국주거학회논문집
• /
• 제24권3호
• /
• pp.1-8
• /
• 2013

The University students learn their major or a general education in lecture rooms. In these days, lecturer use frequently various multimedia in lecture room. Appropriate control lighting environment in lecture room should be essential and related in efficient studying. Daylighting on front-side of lecture room will cause glare and students are hard to read contents on white-board at their seat. Therefore, in order to preventing glare we simulated daylighting of lecture room with using computer software in this study. Results from simulation and analysis as follows: The first, if students' left-side is east-oriented in lecture room, best daylighting condition about glare in lecture room. The second, architectural designers can use simulation data of daylighting or simulate data in designing university buildings with lecture rooms. Finally, if reducing size of windows (narrow and deep daylight: more closing vertically, from up to down daylighting: more closing horizontally) we will be able to reduce energy from lecture room.

• 대한가정학회지
• /
• 제39권6호
• /
• pp.109-122
• /
• 2001

This study was performed to identify the roles of residents for the environmentally sound and sustainable development, taco-polis(kologisches Bauen), eco-village and Symbiotic Housing. These buildings will achieve energy efficiency through design strategies such as passive solar heating system, natural cooling and day lighting. Their infrastructure will feature parking on the periphery, extensive pedestrian paths, outdoor ground lights that preserve stellar visibility, and environmentally sensitive technologies such as low writer use fixtures. And they will restore biodiversity while protecting the wildlife, wetlands, forests, soil, air and water. Their houses wile be designed to support home-based occupations, offering high-speed Internet access and other options to promote a localized, sustainable economy. To support and encourage the evolution of sustainable settlements, it is necessary to prepare constructing the physical facilities and the social functions relating with residents. The roles of residents are important to provide a high Quality lifestyle and to integrate a supportive social environment with a low-impact way of life. This study concluded the four main roles of residents for the sustainable of Eco-polis and Ecovillage. 1. Residents assist transition towards a sustainable society as eco-conscious consumers in the planning stage. 2. Residents live in a ecological way for the sustainable ecovillage. 3. Residents exchange information and education for increasing the community glue as a communication network. 4. Residents support and transmit their cultural vitality and tradition for the next generation. So, users are expected to encourage resident's participation in the planning, design, ongoing management and maintenance of the sustainable ecovillage.

• 조명전기설비학회논문지
• /
• 제13권4호
• /
• pp.1-6
• /
• 1999

이 논문에서는 주유소 조명시설의 실태를 조사하고 주유소의 각 영역별 조도를 측정하여 그 결과를 KS와 IESNA의 기준과 비교하고 주유소의 전체적인 조명패턴을 분석하였다. 주유지역에 있어서 조도는 KS에 제시된 값보다 상당히 높은 반면 IESNA의 기준보다는 대체로 낮음을 알 수 있었다. 그 외의 지역 또한 조도값에 있어서 서로 많은 차이가 발생함을 확인하였다. 이러한 결과로부터 주유소 조명시설의 적절한 유지·보수에 의해 불필요한 에너지 낭비를 줄일 수 있고, 이러한 점을 고려한 설계과정의 필요함을 알 수 있었다. 또한 KS규격에 있어서 다른 나라의 기준과 비교하여 각 영역별 작업특성을 고려한 철저한 평가와 기준설정이 이루어져야 하겠다.

• 전력전자학회논문지
• /
• 제19권1호
• /
• pp.8-14
• /
• 2014

This paper presents the intra capacitance modeling according to the winding method and section bobbin for CM choke capable of the EMI attenuation of broad bands from lower frequency bands to higher frequency bands and high frequency type common-mode choke capable of the EMI attenuation of high frequency band used in the EMI Block of LED-TV SMPS. In case of high frequency type CM choke, it can be explained the parasitic capacitance of A type and section bobbin type winding methods among them is much smaller than the other. The first resonant frequency of the proposed CM choke tends to increase as the parasitic capacitance becomes small and its impedance characteristics also show improved performance as the first resonant frequency increases. In the future, the CM chokes of high frequency type show it can be practically used in not only LED/LCD-TV SMPS but also several applications such as LED Lighting, Adapter and so on.