• Title/Summary/Keyword: power conditioning

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The effects on rehabilitative program on isokinetic muscle power of patients with osteoarthritis of Knee joint (재활프로그램이 슬관절 골관절염 환자의 등속성 근력에 미치는 영향)

  • Kim, Hye-In;Chun, Seung-Chul;Kim, Yong-Seon
    • Journal of Korean Physical Therapy Science
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    • v.13 no.2
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    • pp.7-16
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    • 2006
  • The purpose of this study was to investigerate the changes of isokinetic muscular function in elderly people who have been to take from osteoarthritis in both knee joints after 36 weeks' rehabilitative therapy programs. In this study the subjects were 20 women residing in S-Tower(n=10) and H-welfare Town(n=10) respectively. The rehabilitative group(equal to experimental group) had taken part in exercise program 5 days per week. And then was performed by warm up, workout(involving aerobic exercise and weight training), cool down, physical therapy(cryotherapy, TENS, ultrasound). Also its programs were classified in conditioning phase($0{\sim}12$ weeks), improvement phase($13{\sim}24$ weeks), and maintenance phase($25{\sim}36$ weeks) respectively. The results of inspections were as followed: In the isokinetic muscular function, there were significant differences in right leg's flexor and extensor in $60^{\circ}$/sec. And there were significant differences in right leg's flexor and left leg's extensor in $180^{\circ}$/sec. At last, there were significant differences in right leg's flexor and left leg's extensor in $240^{\circ}$/sec. In other words, the rehabilitative programs for 36 weeks could increase the muscular function in elderly with OA. In conclusion, the rehabilitative programs of this paper has shown the positive results, which involved in the muscular function variables in elderly people with OA in both knee.

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Heating Performance of a Ground Source Heat Pump System through Actual Operation (지열원 히트펌프시스템의 실사용을 통한 난방성능연구)

  • Koo, Kyoung-Min;Jeong, Young-Man;Hwang, Yu-Jin;Lee, Jae-Keun;Jang, Se-Yong;Kim, In-Kyu;Jin, Sim-Won;Lee, Dong-Hyuk
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.1341-1346
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    • 2008
  • This paper presents the heating performance of a water-to-refrigerant type ground source heat pump system (GSHP) installed in a school building. The evaluation of the heating performance has been conducted under the actual operating conditions of GSHP system in the winter. Ten units with the capacity of 10 HP each were installed in the building. Also, a closed vertical typed-ground heat exchanger with 24 boreholes of 175 m in depth was constructed for the GSHP system. For analyzing the heating performance of the GSHP system, we monitored various operating conditions, including the outdoor temperature, the ground temperature, and the water temperature of inlet and outlet of the ground heat exchanger. Simultaneously, the heating capacity and the input power were evaluated for determining the heating performance of the GSHP system. The average heating coefficient of performance (COP) of the heat pump was found to be 5.1 at partial load of 46.9%, while the overall system COP was found to be 4.2.

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Heating Performance of a Ground Source Heat Pump System through Actual Operation (지열원 히트펌프시스템의 실사용을 통한 난방성능연구)

  • Koo, Kyoung-Min;Jeong, Young-Man;Hwang, Yu-Jin;Lee, Jae-Keun;Jang, Se-Yong;Kim, In-Kyu;Jin, Sim-Won;Lee, Dong-Hyuk
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.788-793
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    • 2008
  • This paper presents the heating performance of a water-to-refrigerant type ground source heat pump system (GSHP) installed in a school building. The evaluation of the heating performance has been conducted under the actual operating conditions of GSHP system in the winter. Ten units with the capacity of 10 HP each were installed in the building. Also, a closed vertical typed-ground heat exchanger with 24 boreholes of 175 m in depth was constructed for the GSHP system. For analyzing the heating performance of the GSHP system, we monitored various operating conditions, including the outdoor temperature, the ground temperature, and the water temperature of inlet and outlet of the ground heat exchanger. Simultaneously, the heating capacity and the input power were evaluated for determining the heating performance of the GSHP system. The average heating coefficient of performance (COP) of the heat pump was found to be 5.1 at partial load of 46.9%, while the overall system COP was found to be 4.2.

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An experimental study on the performance improvement of dead-end type PEMFC with pulsating effect (맥동 효과를 이용한 dead-end type 연료전지의 성능향상에 대한 실험적 연구)

  • Choi, Jong-Won;Seo, Jeong-Hoon;Hwang, Yong-Sheen;Lee, Dae-Heung;Cha, Suk-Won;Kim, Min-Soo
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.567-571
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    • 2008
  • PEM Fuel Cell operation mode can be classified into dead-end mode or open mode by whether the outlet port is blocked or not. Generally, dead-end type fuel cell has some merits on the pressure drop and system efficiency because it can generate more power than the open type fuel cell due to high operating pressure condition. However, the periodic purging process should be done for removing water which is formed as product of a reaction in the gas diffusion layer. In this study, cathode side dead-end type operation has been conducted. Moreover, pulsating flow generator at the outlet of cathode side has been suggested for increasing the period to purge the formed water because the pulsating flow can make formed water scattered uniformly over the whole channel. As a result, the purging period with pulsation increased by 1.5-2 times longer than that without pulsating.

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The Construction Status of Fuel Test Loop Facility (핵연료 노내조사시험설비의 시공 현황)

  • Park, Kook-Nam;Lee, Chung-Young;Kim, Hark-Rho;Yoo, Hyun-Jae;Yoo, Seong-Yeon
    • Proceedings of the SAREK Conference
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    • 2007.11a
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    • pp.305-309
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    • 2007
  • FTL(Fuel Test Loop) is a facility that confirms performance of nuclear fuel at a similar irradiation condition with that of nuclear power plant. FTL construction work began on August, 2006 and ended on March, 2007. During Construction, ensuring the worker's safety was the top priority and installation of the FTL without hampering the integrity of the HANARO was the next one. The installation works were done successfully overcoming the difficulties such as on the limited space, on the radiation hazard inside the reactor pool, and finally on the shortening of the shut down period of the HANARO. The Commissioning of the FTL is to check the function and the performance of the equipment and the overall system as well. The FTL shall start operation with high burn up test fuels in early 2008 if the commissioning and licensing progress on schedule.

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Analysis for the Economic efficiency of District Heating and Gas Engine Co-generation System comparing with Central Heating System (중앙난방방식을 지역난방.소형열병합난방방식으로 전환시의 경제성 비교 분석)

  • Kim, Kyu-Saeng;Lee, Sang-Hyeok;Hong, Kyung-Pyo;Won, Young-Jae
    • Proceedings of the SAREK Conference
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    • 2007.11a
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    • pp.459-465
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    • 2007
  • This study was conducted to calculate the LCC of a apartment complex with a type of heating system, district heating and cogeneration system. For the purpose of analyzing LCC according to size of apartment complex, 500, 1,500 and 4,000 houses of model apartment selected. This research performs design of heating system and the life cycle cost analysis including an initial cost, energy cost, maintenance and operation cost, replacement cost and renovation cost during the project period(15years). According to the calculated results, 1) Initial cost of cogeneration system with 500, 1500 and 4000 houses is higher than district heating system each of 20%, 13%, 12%. 2) In case of cogeneration system, the payback period by electric generation is 5.21, 4.92 and 4.47 years and saving cost was calculated 29 billion won, 94 billion won and 262 billion won after payback period. 3) Cogeneration system LCC was 1.12, 1.07 and 1.06 times larger than district system with the size of apartment complex. According to the case of this study district heating system is more efficient than cogeneration system in terms of the reduction of LCC. 4) Gas Engine Co-generation System is more efficient than other systems because it can collect progressive part from electric charge progressive stage system. However, the efficiency is decreasing because of raising of fuel bills(LNG) and lowering of power rate for house use. Especially the engine is foreign-made so the cost of maintenance and repair is high and the technical expert is short. 5) District heating is also affected by fuel bills so we should improve energy efficiency through recovering of waste heat(incineration heat, etc.). Also, we should supply district cooling on the pattern of heat using of let the temperature high in winter and low in summer.

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A Study on the Measurement of Thermal conductivity of Vertical Borehole heat Exchanger (수직형 지중열교환기 열전도도 측정기술에 관한 연구)

  • Kim, Ji-Young;Lee, Euy-Joon;Chang, Ki-Chang;Kang, Eun-Chul
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.39-44
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    • 2008
  • The heat exchange between the Borehole Heat Exchanger(BHE) and the surrounding ground depends directly on ground thermal conductivity k at the certain site. The k is thus a key parameter in designing BHE and coupled geothermal heat pump systems. Currently, although a thermal hydraulic response test(TRT) is mostly used in practice, the thermal hydraulic TRT needs additional power and is generally time-consuming. A new, simple wireless P/T probe for a hi-speed k determination was introduced in this paper. This technique using a wireless P/T probe is less time-consuming and requires no external source of energy for measurement and predicts local thermal properties by measuring soil temperatures along the depth. Measured temperature data along the depth was analyzed. In order to verify the new technique for the determination of ground thermal conductivity, ground thermal conductivity k that calculated from the measured temperature data using a wireless P/T probe was compared with one obtained from conventional hydraulic TRT. When comparing the average k of two methods, the relative error was approximately 10%. As a result, the electronic TRT can replace the conventional hydraulic TRT method after carrying out the additional research on a lot of sites.

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A Study on Curriculum Revision for Fisheries High Schools and Merchant Marine High Schools -I. Colligation Study (제6차(第六次) 수산(水産)·해군계(海運系) 고등학교(高等學校) 교육과정(敎育課程) 각론개발연구(各論開發硏究) -I. 총괄연구(總括硏究))

  • Lee, Byoung-Gee;Park, Hwan-Ho;Choe, Jong-Hwa;Gwak, Han-Cheol;Lee, Hyeong-Suk
    • Journal of Fisheries and Marine Sciences Education
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    • v.4 no.1
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    • pp.1-15
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    • 1992
  • Fishery and shipping industry are ones of the important industries for the Republic of Korea, and the education of competent technicians is a essential-important factor for the further development in these fields. To this end, curriculum for the fisheries and/or merchant marine high schools are rearranged to meet the industrial needs and social change. In this study, the existing goal of education is rearranged inclusively to meet the further development and the curriculum to realize the goal. The departments are reorganized into nine ones by establishing new two. They are Department of Refrigeration Mechanical Engineering and of Automated-ship Operation. Four departments of existing seven-Department of Fish Aquaculture, of Fish Processing, of Marine Engine and of Marine Communication-are renamed into Department of Aquaculture, of Food Processing, of Power Mechanical Engineering and of Electronic Communication respectively. The remaining three departments- Department of Fishing Technology, of Self-managing Fisheries and of Navigation-are unchanged. The specialized subjects are revised as follows; (1) The existing seven subjects especially prepared for the fisheries and/or merchant marine high schools are changed into the common subjects for all the vocational high schools. They are Food Science, Food Hygiene, Food Processing Machinery, Air-conditioning Facilities, Welding and Piping, Communication Law and Introduction to Computer. (2) Two subjects are newly established: Refrigeration Mechanical Engineering and Automated-ship Operation. (3) Four subjects are disused : Sea Training, Fisheries Law, Canned Food and Practice in Communication. (4) Introduction to ship, to Marine Engine and to Marine Communication are merged into Introduction to ship. (5) The compulsory major subject is fixed as Introduction to Fisheries for the fisheries high schools and Introduction to shipping Industry for the merchant marine high schools.

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Case Study on 12kW Building Integrated Photovoltaic System (12kW급 건물일체형 태양광발전시스템 사례분석)

  • Park, Kyung-Eun;Kang, Gi-Hwan;Kim, Hyun-Il;So, Jung-Hoon;Yu, Gwon-Jong;Kim, Jun-Tae;Lee, Kil-Song
    • Journal of the Korean Solar Energy Society
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    • v.29 no.1
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    • pp.18-23
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    • 2009
  • We intend to describe a 12kW building-integrated photovoltaic system which was applied into the south wall of a new building. This study showed the results that were appeared from describing the PV module manufacture and installation process, and performing generation performance analysis of BIPV system. From the result we confirmed that the generation performance of the BIPV system was changed by season. The performance ratio(PR) was about 83.6% in winter and it means that performance of this BIPV system was so good in that season. On the other hand, the PR in summer was about 75.0% dropped about 8%. It was believed that the change was influenced by the reduction of solar radiation irradiated into the PV modules by installation position and rainy spell in summer. And we also confirmed that low irradiation condition is cause of the additional loss in the total PV system. In this case, the efficiency ratio of PCS drops significantly at low input loads and the average conversion efficiency of PCS in summer was 76.4% decreased about 10% from 86% in winter.

Performance Characteristics of Natural Gas Liquefaction Process using Liquid-gas Heat Exchanger (액-가스 열교환기를 적용한 천연가스 액화공정 성능 특성)

  • Yoon, Jung-In;Yoo, Sun-Il;Oh, Seung-Taek;Lee, Ho-Saeng;Lee, Sang-Gyu;Choi, Keun-Hyung
    • Journal of the Korean Institute of Gas
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    • v.13 no.6
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    • pp.44-48
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    • 2009
  • In this paper, two different types of natural gas liquefaction cycle with 2 staged compression were designed and simulated to develop liquefaction process which is the core technology in the Industry of natural gas liquefaction plant. These include the cascade cycle with inter-cooler which is consisted of propane, ethylene and methane cycle. One of these is that liquid-gas heat exchanger is applied to between methane and ethylene cycles, and another is that liquid-gas heat exchanger is added to between ethylene and propane on the above process. Also, these cycles are compared with two staged cascade process using an inter-cooler. The COP of process2 is shown about 14.0% higher than that of process1, respectively. Also, the yield efficiency of LNG improved comparing with process1 with 11.5% lower specific power.

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