• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1007-1012
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• 2008

Demand for the highly efficient and high performance urban energy supply system having been continuously increased according to the rise of quality of life and continuously increased energy cost all over the world. The district heating and cooling system is very effective way for energy saving, cost reduction, and demand side management of energy. There are several district cooling supply technologies such as chilled water direct transportation, installation of absorption type chiller in the user side, and desiccant cooling. This study investigates the advantage and technical problems of each district cooling technology. Also, it is necessary political and financial support system for the extension of district cooling system.

• Plant Journal
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• v.6 no.2
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• pp.56-61
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• 2010

In this paper, an integrated management software is developed to promote the business competitive power. The interoperability among the software accounts for an ever growing performance of petrochemical plant project. If the interoperability is built up, company has taken advantages of quality, schedule, cost, and safety by active communication. The advantage of an integrated management software is examined in three aspects. In efficiency aspect, It takes advantage of the saving about the various information and the standard of project performance procedure. In quality, the integration gave aid to a quality improvement through team collaboration and data management within project life cycle. In cost, poor communications between systems waste 30% of project costs. If information could be inputted once and used by all, reductions in delivery time up to 40% were possible. Therefore, 10% savings of engineering cost was also possible.

• Solar Energy
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• v.19 no.3
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• pp.1-11
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• 1999

Previous researchers have studied how to reduce a pumping power in order to save energy in the fluid transporting system. Especially, it has been studied a lot about reducing the pressure drop among parameters related to the energy saving for fluid transport. This study is to investigate the effect of a substantial drag reduction caused by the polymer(A611P, A601P) when the working fluids flow to the vertical and horizontal direction in the vertical cylindrical equipment of closed flow system. In this experiment, we mount a visualization equipment on the test section and take pictures. With using the PIV system, instrument and analyzing the movement of bubble for different polymer concentration are observed and some mechanism of the drag reduction effect is clarified.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.124-126
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• 2004

본 논문은 CAM(Constant Awake Mode), 및 PSM(Power Saving Mode)을 지원하는 IEEE 802.l1b[1] Infrastructure 환경에서 전송 프로토콜이 이동기기의 WNIC(Wireless Network Interface Card) 에너지 소비에 미치는 영향을 분석하고 단위 시간 동안 전송되는 데이터 양에 기반한 IEEE 802.l1b WNIC 에너지 모델을 제안한다. 제안하는 에너지 모델은 IEEE 802.l1b 환경에서 CAM 및 PSM 모드를 사용할때, 실제 측정한 값을 기반으로 설계되었다. 제안된 에너지 모델은 실험을 통하여 정확성을 검증하고, IEEE 802.l1b를 기반으로한 저전력 통신 관련 연구에서 시뮬레이션 시 사용 가능한 에너지 모델임을 밝힌다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.109-115
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• 2009

Recently, the relay communication is focused for the power saving and coverage extension of ad-hoc networks. For the high date rate transmission, it is proposed to adapt OFDMA relays. In this paper, we assume the 2 hop cooperative OFDMA relays between the source and the destination. The performance of 3 different relaying methods are derived and compared. We noticed that the selective OFDMA relaying method has the best performance followed by opportunistic OFDMA relaying and repetition-based OFDMA relaying method under the same threshold mutual information rate.

• Journal of Environmental Science International
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• v.25 no.10
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• pp.1389-1396
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• 2016

A monitoring system for a field magnetometer was configured with assistance of a Raspberry Pi as a data logger. The suggested geomagnetic system uses a semi-real-time data transmission module. The system consists of two parts: a field-observation part and a data-center part. The field-observation part comprises a Raspberry Pi, magnetometer, LTE router, and power source, while the data center part takes samples at the site. The collected magnetometer data are then sent to the data center through the LTE router. The newly designed monitoring system was deployed and checked in Jeju-do island, and found to operate stably. The suggested system is promising in that it is simple and cost saving, providing at least physical insight and knowledge on the complex natural phenomena.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.4
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• pp.22-27
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• 2012

In the study, an XML based platform is presented for LED dimming control. The XML platform is designed in an open architecture, providing with interoperability and scalability. Also, it enables the accommodation of off-the-shelf wired and wireless communication protocols and make it fast and easy to implement various application programs for LED dimming, comparing to the legacy platforms. In the study, a test best has been built for demonstration of the merits of the XML platform with dimming control by responding to the scenario of demand response event. Benefit calculation of the power saving and incentive from demand response shows the applicability and usefulness of the XML platform.

• Proceedings of the KIPE Conference
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• 2019.11a
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• pp.166-167
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• 2019

Smart windows are used as windows and doors to determine cooling and heating efficiency in the construction field. It's characteristics can increase the energy saving efficiency. In addition, the function of the smart window that can control the light transmittance transmitted from the external environment of the building to the building according to the needs of the user is attracting attention. In this study, a liquid crystal cell capable of controlling light transmittance of 297 × 210 ㎟ was fabricated by using a liquid crystal device as an optical shutter. Analysis of transmittance change according to driving voltage and driving stability according to thermal environment, We confirmed the applicability of building exterior materials as smart windows.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.10a
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• pp.209-212
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• 2003

The superconducting generator and motor have many advantages over the conventional machines. The better characteristics originates from the higher magnetic field density by way of superconducting field coil which conducts the operating current with very large density. The major merits of the superconducting machines can be explained as the smaller size and weight as well as the higher efficiency. The compactness would be very useful for the applications such as ship propulsion motors and the higher efficiency is expected to play a good role in saving the electricity generation cost for the generators used in power plants. In spite of these advantages the main reason for the lazy commercialization is known as the expensiveness of the superconductors and the cryogenic systems. In this paper focusing on the superconducting generator, we will consider and estimate the economic effectiveness when the machines permeate into the actual AC generator market in Korea gradually.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.155-160
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• 2007

This study describes thermal performance of Plus50 eco-building with new technology such as power window system, green wall, structure material, etc. The Plus50 eco-building is house experimental which is constructed by Korea Institute of Construction Technology. In order to estimate thermal performance of the building, TRNSYS program and Prebid, and its sub-modules are used. The results showed that maximum heating and cooling load in the building are calculated at 1st floor and 4th floor, respectively. And also energy saving of the building is calculated as over 30% compared to conventional apartment house.