• 제목/요약/키워드: Energy Consumption Efficiency

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설비공학 분야의 최근 연구 동향 : 2016년 학회지 논문에 대한 종합적 고찰 (Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2016)

  • 이대영;김사량;김현정;김동선;박준석;임병찬
    • 설비공학논문집
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    • 제29권6호
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    • pp.327-340
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    • 2017
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2016. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of flow, heat and mass transfer, the reduction of pollutant exhaust gas, cooling and heating, the renewable energy system and the flow around buildings. CFD schemes were used more for all research areas. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results of the long-term performance variation of the plate-type enthalpy exchange element made of paper, design optimization of an extruded-type cooling structure for reducing the weight of LED street lights, and hot plate welding of thermoplastic elastomer packing. In the area of pool boiling and condensing, the heat transfer characteristics of a finned-tube heat exchanger in a PCM (phase change material) thermal energy storage system, influence of flow boiling heat transfer on fouling phenomenon in nanofluids, and PCM at the simultaneous charging and discharging condition were studied. In the area of industrial heat exchangers, one-dimensional flow network model and porous-media model, and R245fa in a plate-shell heat exchanger were studied. (3) Various studies were published in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, subjects include mobile cold storage heat exchanger, compressor reliability, indirect refrigeration system with $CO_2$ as secondary fluid, heat pump for fuel-cell vehicle, heat recovery from hybrid drier and heat exchangers with two-port and flat tubes. In the alternative refrigeration/energy system category, subjects include membrane module for dehumidification refrigeration, desiccant-assisted low-temperature drying, regenerative evaporative cooler and ejector-assisted multi-stage evaporation. In the system control category, subjects include multi-refrigeration system control, emergency cooling of data center and variable-speed compressor control. (4) In building mechanical system research fields, fifteenth studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, renewable energies, etc. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which could be help for improving the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the analyses of indoor thermal environments controlled by portable cooler, the effects of outdoor wind pressure in airflow at high-rise buildings, window air tightness related to the filling piece shapes, stack effect in core type's office building and the development of a movable drawer-type light shelf with adjustable depth of the reflector. The subjects of building energy were worked on the energy consumption analysis in office building, the prediction of exit air temperature of horizontal geothermal heat exchanger, LS-SVM based modeling of hot water supply load for district heating system, the energy saving effect of ERV system using night purge control method and the effect of strengthened insulation level to the building heating and cooling load.

LED형 매립형 항공등 시스템의 개발 시험에 대한 고찰 (The Consideration of the Development Testing for LED type In-pavement Aeronautical Lights)

  • 이상철;신재흥;이승연;임근영;임민수
    • 전기학회논문지P
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    • 제61권3호
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    • pp.140-148
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    • 2012
  • Aeronautical lights, which are internationally standardized sequence of colors and placements, are aeronautic safety devices that provide visual information to pilots by continuously adjusting their light intensity to appropriate level. In this paper, we consider the development testing for in pavement LED aeronautical light system such as taxiway centerline, stop line and temporary stop line. The test results of LED sourced lights have shown a drastic improvement in power consumption levels and cost efficiency compared to their halogen sourced counterparts The LED light used only 42.7% as much power as their halogen sourced counterparts. Taking installation costs into account, LED will cost only 58% of its halogen counterparts. These results suggest that developing the LED sourced aeronautical light would result in globally competitive products thar guarantees satisfaction to their consumers, and that both cost effective and energy efficient.

전해 커패시터를 제거하고 디밍이 가능한 고수명 단일단 PFC DCM 플라이백 컨버터 (Single-stage Dimmable PFC DCM Flyback Converter without Electrolytic Capacitor)

  • 진달래;김춘택;채민철;나재두;김영석
    • 전기학회논문지
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    • 제62권11호
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    • pp.1550-1559
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    • 2013
  • Light emitting diode(LED) lighting has been applied various industry fields because of its high efficiency, low power consumption, long life time, and environment friendly characteristics. Generally, LED lighting needs a driver to maintain constant current. Most popular driver is the switching converter. In the converter, there are several electrolytic capacitors. However the lifespan of the electrolytic capacitor is much shorter than LED. Therefore the lifespan of LED lighting with electrolytic capacitor is decreased. Also, LED lighting needs dimming control because of various needs and energy saving. This paper presents the dimmable single-stage PFC DCM flyback converter without electrolytic capacitor and parallel LC resonant filter for reducing 120[Hz] ripple on the output. The type 2 controller is used to maintain constant current and the analog dimming control is used. The proposed converter is verified through simulation and experimental works.

Primary user localization using Bayesian compressive sensing and path-loss exponent estimation for cognitive radio networks

  • Anh, Hoang;Koo, Insoo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제7권10호
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    • pp.2338-2356
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    • 2013
  • In cognitive radio networks, acquiring the position information of the primary user is critical to the communication of the secondary user. Localization of primary users can help improve the efficiency with which the spectrum is reused, because the information can be used to avoid harmful interference to the network while simultaneity is exploited to improve the spectrum utilization. Despite its inherent inaccuracy, received signal strength based on range has been used as the standard tool for distance measurements in the location detection process. Most previous works have employed the path-loss propagation model with a fixed value of the path loss exponent. However, in actual environments, the path loss exponent for each channel is different. Moreover, due to the complexity of the radio channel, when the number of channel increases, a larger number of RSS measurements are needed, and this results in additional energy consumption. In this paper, to overcome this problem, we propose using the Bayesian compressive sensing method with a calibrated path loss exponent to improve the performance of the PU localization method.

국내 유통 첨가제의 배출가스 및 연비특성 (Characteristics of Emission and Fuel Economy of Fuel Additives in the Domestic Market)

  • 김성우;이민호;인정민;김재권;정충섭
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 추계학술대회 초록집
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    • pp.165.1-165.1
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    • 2010
  • In the past, drivers bought a fuel additives to treat a combustion chambers or injector nozzles for carbon or gum deposit at market. But, nowadays, as raised cost of fuel for a vehicle the consumers also start focusing on a function of fuel additives that increases fuel economy of one. Some fuel additive manufacturers and agents advertise that their goods make a car it's initial state. This paper shows data for 3 years that were acquired during test for registration of an additive in domestic. The data were sorted according to kind of vehicle, kind of fuel, test mode, CO, HC, NOx, PM, total emission, fuel economy and accumulated mileage. And than by using simple linear regression analysis changes according to accumulated mileage was displayed. Normal distribution and histogram of rate of increase and decrease were displayed. the analyzed data indicated that a fuel additive maintain and make a car the first state of one but can't make a car be batter than initial the one.

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IMV를 이용한 굴착기 작업장치 궤적제어 (Trajectory Control of Excavator Actuators Using IMV)

  • 정규홍
    • 드라이브 ㆍ 컨트롤
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    • 제17권2호
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    • pp.45-54
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    • 2020
  • The IMV is a combination of four two-way valve systems which replace a conventional four-way spool valve to improve efficiency mostly in excavator hydraulics. As the environmental regulations for construction equipment have tightened, some overseas advanced companies have released commercial excavators in which the MCV is implemented with the IMVs. Development of the IMV type MCV relies on the control algorithm as well as the robust performance of proportional flow control valves. In this study, the IMV controller was designed and verified with experiments for the excavator working unit, which determines the IMV mode of operation and the extent of the valve opening in consideration of the load conditions on hydraulic actuators. First, the open-loop controller was designed with a joystick command vs. a PSV reference current map comprising several control parameters in to compensate for the different flow characteristics and non-linearities of two-way flow control valves. Second, the closed-loop controller was designed with the PI control fed by the actuator displacement and outputs actuator percent effort equivalent to the operator's joystick command. Finally, the performance of the IMV type MCV was verified with the trajectory control of position references derived from the energy consumption test standard. Experimental results showed the control performance of the IMV developed in this study, and suggest that future studies to be conducted to advance technical progress.

수중 침지식 생분해성 PBSAT 그물 열처리기 개발과 성능 분석 (Development of the submerged heat treatment machine for PBSAT(polybutylene succinate adipate-co-terephthalate) monofilament nets and its efficiency)

  • 박성욱;김성훈;임지현;최혜선
    • 수산해양기술연구
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    • 제51권1호
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    • pp.94-101
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    • 2015
  • The heat treatment machine based on immersion was developed to reduce temperature difference during netting process and appraised it performance compared current heat treatment machine using high pressure. It was also reviewed the optimum heat treatment procedures for PBSAT monofilament net in accordance with the immersion time and temperature. The procedure was based on physical measurement such as breaking load, elongation and angle of the mesh for PBSAT monofilament. The water temperature gap of the treatment machine based on immersion was less than $1^{\circ}C$. and the energy consumption was also increased in high temperature condition. It was identified that the optimum temperature was $75^{\circ}C$ and its optimum processing time was between 15 minutes and 20 minutes to get qualified physical properties.

ITO 나노입자 면상발열체의 온도유지에 대한 연구 (Temperature Maintenance of an ITO Nanoparticle Film Heater)

  • 양경환;조경아;임기주;김상식
    • 전기전자학회논문지
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    • 제20권2호
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    • pp.171-173
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    • 2016
  • 본 연구에서는 휴대용 온열기의 에너지 효율을 향상시키기 위하여 indium tin oxide (ITO) 나노입자 페이스트와 PDMS를 이용하여 PDMS/ITO 나노입자 박막 면상발열체를 제작하였고, ITO 나노입자 박막 면상발열체와 PDMS/ITO 나노입자 면상발열체의 온도 유지특성 및 소비전력량을 분석하였다. PDMS층의 낮은 열전도도로 PDMS/ITO 나노입자 박막 면상발열체의 온도유지시간이 ITO 나노입자 박막 면상발열체에 비해 1.5배 증가하였으며, 소비 전력량은 35% 절감되었다.

오래 달리기 시 하지 근지구력에 따른 몸통의 3차원 각 변화 (Three Dimension Angle Change of the Trunk to the Muscular Endurance during a Prolonged Running)

  • 김태삼;이연종
    • 한국운동역학회지
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    • 제17권2호
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    • pp.61-73
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    • 2007
  • The purpose of this study was to investigate the influence of the muscular endurance on the kinematic factors during a prolonged run. Subjects, 12 males, who were divided into three groups(lower group, general group, and in higher group) after measuring the lower limb's muscular endurance previously. They were asked toe run on the treadmill at 7.4km/h of speed. To analyze the kinematics parameters of the trunk during running, the ProReflex MCU Camera(Qualisys, Sweden) were used. All parameters were sampled from 5 minute, 40 minute, and 60 minute moments during running. An ANOVA with Repeated Measure was used to test the statistic significance between and within groups for all parameters determined with SPSS 11.0. Significance was defined as p<.05. The conclusions were as follows; There was significantly difference within(lapse of running time) groups in the take-off and minimum knee angle event of swing phase of the trunk flexion and extension. In conclusion, the muscular endurance affected on movement of the trunk during a prolonged run. In addition, it showed that there was significant difference in the energy consumption by lapse of running time. Therefore, it seems to be relationships between the muscular endurance and running efficiency.

LED조명용 비구면 Plastic Lens의 성능향상을 위한 광학설계 (Optical Design considering Efficiency Improvement of Aspheric Plastic Lens for LED Lighting)

  • 이학석;박종락;김민재;김혜정;김정호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 하계학술대회 논문집
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    • pp.289-289
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    • 2009
  • Light emitting diode(LED) has many advantages including lower energy consumption and longer lifetime and eco-friendly in comparison with traditional light sources. Spheric plastic lens generally used in LED lighting occurs aberration and ghost image which give displeasure and deteriorate vision quality in human eyes. Using the optical program (LightTools$^{TM}$, CodeV$^{TM}$), we were confirm the aberration and ghost image in optical simulation and employed aspheric lens form in the lens design to improve these problems. From the comparison of the simulation results between the aspheric lens and the spheric lens, we were ascertain to be improved both aberration and Ghost image.

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