• Title/Summary/Keyword: PV/T

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Economic Evaluation of Unused Space PV System Using the RETScreen Model - A Case Study of Busan, Gangseo-gu - (RETScreen 기반 유휴공간 태양광 발전 시스템의 경제성 평가 연구 - 부산시 강서구 사례를 중심으로 -)

  • Kang, Seongmin;Jeon, Youngjae;Cho, Sung Heum;Lee, Daekyeom;Jeon, Eui-Chan
    • Journal of Climate Change Research
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    • v.8 no.1
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    • pp.21-30
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    • 2017
  • Recently, There has been much discussed about unused space. This space can be used in a variety of ways. Utilizing it as a facility, craft shop, and utilizing renewable energy generation facilities. Especially, in terms of climate change should be supplied renewable energy. Renewable energy needs to be developed in terms of responding to climate change, and the recent Paris agreement is also emphasizing the importance of renewable energy. In particular, renewable energy needs to be widely disseminated. And renewable energy is limited space. In this regard, idle land can provide opportunities for securing new renewable energy generation facilities. The introduction of new and renewable energy facilities in idle space can enhance the self-sufficiency rate of the local community, which is significant in terms of responding to climate. In this study, to investigate the possibility of utilizing a unused space for a photovoltaic power generation facility, we investigated the amount of electricity which could be generated through photovoltaic power generation, and the economic effects, using a RETScreen model. The results showed that 9,738 MWh of power can be generated and that $4,540tCO_2eqcan$ be saved. Regarding the economic effect, the net present value of the facility was shown to be 2,247,389,020 KRW. As the net present value was shown to be positive, we believe that the installation of a photovoltaic power generation facility in an unused space would have a positive economic effect. We found the net present value following the fluctuation of the SMP price to be positive, though there was some variation. However, as the economic efficiency was shown to be low because the net present value in relation to the maintenance costs was negative, we believe that maintenance costs must be taken fully into account when evaluating economic efficiency. In particular, as subsidies can be used to cover maintenance costs which must be factored into photovoltaic power generation, we believe that photovoltaic power generation can have an economic effect. Because spaces not currently in use can have a positive economic effect as renewable energy power generation facilities, and can also contribute to the reduction of greenhouse gas emissions, unused spaces are thought to greatly help local governments to cope with climate change as well as reinforcing their related capabilities. We believe our study will help local governments with decisions relating to unused real estate utilization in the future.

Relationships between Nailfold Plexus Visibility, and Clinical Variables and Neuropsychological Functions in Schizophrenic Patients (정신분열병 환자에서 손톱 주름 총 시도(叢 視度) (Nailfold Plexus Visibility)와 임상양상, 신경심리 기능과의 관계)

  • Kang, Dae-Yeob;Jang, Hye-Ryeon
    • Korean Journal of Biological Psychiatry
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    • v.9 no.1
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    • pp.50-61
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    • 2002
  • Objectives:High nailfold plexus visibility can reflect central nervous system defects as an etiologic factor of schizophrenia indirectly. Previous studies suggest that this visibility is particularly related to the negative symptoms of schizophrenia and frontal lobe deficiency. In this study, we examined the relationships between nailfold plexus visibility, and various clinical variables and neuropsychological functions in schizo-phrenic patients. Methods:Forty patients(21males, 19 females) satisfying the DSM-IV criteria for schizophrenia and thirty eight normal controls(20 males, 18 females) were measured for Plexus Visualization Score(PVS) by using the capillary microscopic examination. For the assessment of psychopathology, process-reactivity, premorbid adjustment, and neuropsychological functions, we used Positive and Negative Syndrome Scale(PANSS), Ullmann-Giovannoni Process-Reactive Questionnaire(PRQ), Phillips Premorbid Adjustment Scale(PAS), Korean Wechsler Adult Intelligence Scale(KWIS), Continuous Performance Test(CPT), Wisconsin Card Sort Test (WCST), and Word Fluency Test. We also collected data about clinical variables. Results:PVS was correlated with PANSS positive symptom score and composite score negatively. There were no correlations between PVS and PRQ score, PAS score and neuropsychological variables respectively. Conclusions:This study showed that nailfold plexus visibility was a characteristic feature in some schizophrenic patients, and that higher plexus visibility was associated with the negative symptoms of schizophrenia. There was no association between plexus visibility and neuropsychological functions.

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Comparison of Electrocardiographic Time Intervals, Amplitudes and Vectors in 7 Different Athletic Groups (운동종목별(運動種目別) 선수(選手)의 심전도시간간격(心電圖時間間隔), 파고(波高) 및 벡터의 비교(比較))

  • Kwon, Ki-Young;Lee, Won-Jung;Hwang, Soo-Kwan;Choo, Young-Eun
    • The Korean Journal of Physiology
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    • v.19 no.1
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    • pp.61-72
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    • 1985
  • In order to compare the cardiac function of various groups of athletes, the resting electrocardiographic time intervals, amplitudes and vectors were analyzed in high school athletes of throwing(n=7), jumping(n=11), short track(n=8), long track(n=14), boxing(n=7), volleyball(n=8) and baseball(n=9), and nonathletic control students(n= 19). All athletic groups showed a significantly longer R-R interval(0.96-1.09 sec) than the controls (0.78 sec). Therefore, the heart rate was significantly slower in atheletes than in the control, but was not different among the different athletic groups. R-R interval is the sum of intervals of P-R, 0-T and T-P: P-R and Q-T intervals showed no difference among the control and athletic groups, but T-P interval in the jump, short track, long track and boxing groups was significantly higher than the control. R-B interval showed a significant correlation with T-P or Q-T intervals but no correlation with P-R or QRS complex. Comparing the amplitude of electrocardiographic waves, the athletic groups showed a lower trend in P wave than the controls. T wave in lead $V_5\;(Tv_5)$ was similar in the athletic and control groups. The long track group showed a significantly higher waves of $Rv_5$, $Sv_1$, and the sum of $Rv_5$ and $Sv_1$ than not only the controls but also the other athletic group. The angles of P, QRS, and T vector in the frontal and horizontal planes were not different among the control and all the athletic groups. Each athletic group stowed a lower trend in amplitude of P vector in the frontal plane, but in horizontal plane, throwing, jump, short track and baseball groups showed a significantly lower than the controls. The amplitude of QRS and T vector was similar in the athletic and control groups, but only the baseball group showed a significantly higher QRS vector in the frontal plane. In taken together, all the athletic groups showed a slower heart rate than the controls, mainly because of elongated T-P interval. Comparing the electrocardiographic waves and vector, the athletic groups showed lower amplitudes of P wave and P vector than the controls. Values of $Rv_5$ and $Sv_1$ strongly suggest that only the long distance runners among the various athletic groups developed a left ventricular hypertrophy.

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Utility Interactive Solar Power Conditioner with Zero Voltage Soft Switching High frequency Sinewave Modulated Inverter Link

  • Terai H.;Sumiyoshi S.;Kitaizumi T.;Omori H.;Ogura K.;Chandhaket S.;Nakaoka M.
    • Proceedings of the KIPE Conference
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    • 2001.10a
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    • pp.668-672
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    • 2001
  • The utility interactive sinewave modulated inverter for the solar photovoltaic (PV) power conversion and conditioning with a new high frequency pulse modulated link is presented for domestic residential applications. As compared with the conventional full-bridge hard switching PWM inverter with a high frequency AC link, the simplest single-ended quasi-resonant soft switching sinewave modulated inverter with a duty cycle pulse control is implemented, resulting in size and weight reduction and low-cost. This paper presents a prototype circuit of the single-ended zero voltage soft switching sinewave inverter for solar power conditioner and its operating principle. In addition, this paper proposes a control system to deliver high quality output current. Major design of each component and the power loss analysis under actual power processing is also discussed from an experimental point of view. A newly developed interactive sinewave power processor which has $92.5\%$ efficiencty at 4kW output is demonstrated. It is designed 540mm-300mm-125mm in size, and 20kg in weight.

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A study on Optimal Operation of Protection Coordination Devices Evaluation System in Distribution System with Distributed Sources (분산전원이 연계된 배전계통에 보호협조기기 평가시스템의 최적운용에 관한 연구)

  • Ji, Sungho;Song, Bangwoon;Kim, Byungki;Rho, Daeseok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.6
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    • pp.2971-2978
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    • 2013
  • Recently, with the world-wide issues about global warming and CO2 reduction, a number of distributed generations(DGs) such as photovoltaic(PV) and wind power(WP), are interconnected with the distribution systems. However, DGs can change the direction of the power flow from one-direction to bi-direction, and also change the direction and amount of fault current of existing distribution systems. Therefore, it may cause the critical problems on the power quality and protection coordination. This paper proposes an operation algorithm for bi-directional protection coordination using and apply it for the evaluation system for protection coordination. From the simulation results It is found that the proposed method is more effective and convenient than existing method.

Evaluation of Disease Resistance of a Leaffolder-resistant (Cry1Ac1) Rice Event and Gene Transfer to Plant Pathogens (혹명나방 저항성벼(Cry1Ac1)의 병해 저항성 및 병원균으로의 유전자 전이)

  • Nam, Hyo-Song;Shim, Hong-Sik;Yu, Sang-Mi;Lee, Se-Won;Kwon, Soon-Jong;Kim, Myung-Kon;Lee, Yong-Hoon
    • Research in Plant Disease
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    • v.15 no.3
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    • pp.202-208
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    • 2009
  • The genetically modified leaffolder-resistant (Cry1Ac1) rice plant was evaluated for the changes of resistance by comparing the occurrence of major diseases with a japonica type Korean rice variety, Nakdong which was the mother plant of the transgenic rice event, in greenhouse and field conditions. There was no difference in the occurrence of sheath blight and Helminthosporium blight between the two varieties in the fields. We couldn't find any difference of resistance for fungal blast and bacterial leaf blight by artificial inoculation in greenhouse. There was also no difference in the susceptibility to sheath blight in artificial inoculation tests confirming the results in the fields. The possibility of gene transfer of Bar and Cry1Ac1 from the genetically modified rice plant to naturally infected pathogens such as Fusarium moniliforme and Pyricularia oryzae in the field conditions was tested by PCR. And the possible transfer of those genes by continuous inoculation of Xanthomonas oryzae pv. oryzae and Rhizoctonia solani was also tested. However, we couldn't find any possibility of transfer of the genes in natural and artificial conditions.

The Calmodulin-Binding Transcription Factor OsCBT Suppresses Defense Responses to Pathogens in Rice

  • Koo, Sung Cheol;Choi, Man Soo;Chun, Hyun Jin;Shin, Dong Bum;Park, Bong Soo;Kim, Yul Ho;Park, Hyang-Mi;Seo, Hak Soo;Song, Jong Tae;Kang, Kyu Young;Yun, Dae-Jin;Chung, Woo Sik;Cho, Moo Je;Kim, Min Chul
    • Molecules and Cells
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    • v.27 no.5
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    • pp.563-570
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    • 2009
  • We previously isolated the OsCBT gene, which encodes a calmodulin (CaM)-binding protein, from a rice expression library constructed from fungal elicitor-treated rice suspension cells. In order to understand the function of OsCBT in rice, we isolated and characterized a T-DNA insertion mutant allele named oscbt-1. The oscbt-1 mutant exhibits reduced levels of OsCBT transcripts and no significant morphological changes compared to wild-type plant although the growth of the mutant is stunted. However, oscbt-1 mutants showed significant resistance to two major rice pathogens. The growth of the rice blast fungus Magnaporthe grisea, as well as the bacterial pathogen Xanthomonas oryzae pv. oryzae was significantly suppressed in oscbt-1 plants. Histochemical analysis indicated that the hypersensitive-response was induced in the oscbt-1 mutant in response to compatible strains of fungal pathogens. OsCBT expression was induced upon challenge with fungal elicitor. We also observed significant increase in the level of pathogenesis-related genes in the oscbt-1 mutant even under pathogen-free condition. Taken together, the results support an idea that OsCBT might act as a negative regulator on plant defense.

Diagnostic value of various screening tests in neonatal sepsis (신생아 패혈증의 다양한 선별검사들의 진단적 가치)

  • Je, Hyun Gon;Jeoung, Young Mi;Jeong, Soo Jin
    • Clinical and Experimental Pediatrics
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    • v.49 no.11
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    • pp.1167-1173
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    • 2006
  • Purpose : To evaluate various sepsis screening tests, individually and in combination, to formulate a guideline for the diagnosis of neonatal sepsis. Methods : The study was a retrospective cohort study. It took place at the neonatal intensive care unit of the Paediatric Department, Il Sin Christian Hospital, Busan, Korea, over a period of 68 months from 1st, April, 2001 to 31st, December, 2005. This study evaluated 100 neonates having clinical features of sepsis and 100 normal asymptomatic neonates and used screening tests including C-reactive protein (CRP), total leukocyte count (TLC), absolute neutrophil count (ANC), immature neutrophils to total neutrophil count ratio (I/T ratio), thrombocytopenia, degenerative changes in the neutrophils and gastric aspirate cytology (GAC) for the diagnosis of neontal sepsis. Results : The sensitivity of CRP and ANC was high. CRP had 86 percent sensitivity for group-A (proven sepsis) and 74 percent sensitivity for group-B (probable sepsis) and 94 percent specificity for group-A, B. ANC had sensitivity of 72 percent for group-A and 62 percent for group-B and 86 percent specificity for group-A, B. For group-A, sensitivity, specificity of GAC for polymorphs was 74 percent and 94 percent respectively. As for sensitivity, specificity of platelet count for group-A was 64 percent and 89 percent respecively. The sensitivity, specificity and predictive values (PV) of the individual tests and different test combinations were also calculated for group-A and B. Conclusion : For the detection of culture negative cases in neonatal sepsis, screening tests including CRP, TLC, ANC, thrombocytopenia, cytoplasmic vacuolization in the neutrophils and GAC for polymorphs have high sensitivity. A combination of three tests has higher sensitivity.

C00rdinated Testing between transformer Tap Selection and Inverter Voilage Control in the PV Distributed Generation system (태양광 분산 발전 시스템의 계통연계용 변압기탭 선정과 인버터전압조정 협조시험)

  • Yoon, kap koo;CHO, SeongSoo
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1098-1099
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    • 2015
  • ${\bullet}$ 시험대상: 영월태양광 4,990kW(998kW ${\times}$ 5호) ${\bullet}$ 13.07.31 연계기술검토의뢰 ${\bullet}$ 13.08.28 한전검토결과: 인근변전소 영월S/S(40MW) 초과로 10.8km 지점의 평창 D/L 평창간 347호 주진S/S에 다음의 보완대책과 연계 권고 ${\cdot}$ 문제점: 적정전압이탈 및 순시전압변동률 유지불가 ${\cdot}$ 연계기준만족을 위해 한전에서 제시한 보완대책 : 계통용량증설(설비보강), 연계용량 감소 및 전용선로 연계 ${\bullet}$ 14.01.09 분산형설치자의 용역사(에이스기술단)에서 송배전용전기설비 이용규정과 연계기준 만족을 위한 보완대책 제안 ${\cdot}$ 태양광발전시스템 인버터 자동전압(역률/무효전력) 조정기능 및 감시설비 구비 ${\cdot}$ 최적 공통연결점 선정: 분산형전원으로 부터 전기적으로 가장 가까운 영월D/L 영월S/S측에 개폐장치설치 하고 주진S/S 측으로 연계 ${\bullet}$ 14.01.29~06.19 한전(전력연구원)의 유효성 검토 ${\cdot}$ 보완대책 기술적 유효(실증시험 시행 후 시행공문 발송 예정) ${\bullet}$ 14.08.08 송배전용전기설비 이용규정 개정에 따른 협의 ${\cdot}$ 변압기 대당 20MW에서 25MW ${\cdot}$ 변전소 전체 60MW에서 75MW까지 허용 ${\cdot}$ 영월 S/S 측 문곡/영월 D/L 연계 공사 협의 ${\bullet}$ 14.10.04 사용전검사, 한전계통연계운전 시작 ${\bullet}$ 인버터 고정역률(99.9~100%) 운전 시험 ${\cdot}$ 14.11.21 22.9kV 계전기(SEL-751) 5대, 15분 간격 자료저장 ${\cdot}$ SEL-751/USB to RS232C/노트북 15분간격 측정(첨부) ${\bullet}$ 14.03.07 인버터 역률 95.0% 조정 15분간격 측정(첨부) ${\bullet}$ 변압기탭 선정과 인버터전압조정협조시험 계획 ${\cdot}$ 변압기탭을 현장에서 상하 1탭씩 변경 ${\cdot}$ 인버터역률을 인버터공급사에서 원격조정 ${\cdot}$ 22.9kV 보호계전기 SEL-751, 15분 간격 측정 ${\cdot}$ 인버터 370V 계전기 K-PAM DG3000/현장감시설비 연계 ${\cdot}$ 15분 간격 측정 저장 ${\cdot}$ 현장감시설비/인터넷 연결 원격측정(첨부예정)

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Energy Performance Evaluation of Low Energy Houses using Metering Data (실측데이터를 이용한 저에너지주택의 에너지성능평가)

  • Baek, Namchoon;Kim, Sungbum;Oh, Byungchil;Yoon, Jongho;Shin, Ucheul
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.7
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    • pp.369-374
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    • 2015
  • This study analyzed analyzes the energy performance of six houses in Daejeon completed which were built in 2011. Observed The observed houses, which were all designed and constructed inof the same size and structure, are were highly insulated with triple Low-E coating windows; the insulation level of the walls is was $0.13W/m^2K$ and that of the roof is was $0.10W/m^2K$. As electric houses, all of the energy supplied to the houses, including for cooking, is was supplied by electricity. A and 3~4 kWp of photovoltaic system and a 3~5 kW of ground source heat pump (GSHP) were installed in each house tofor providing provide space heating/and cooling and hot water are installed. We constructed a Web-based remote monitoring system in order to understand energy consumption and the dynamic behavior of the energy system. T, and the results of our metering data analysis of 2013 are as follows. First, the annual residential energy consumption is was 4,400 kWh (${\sigma}=1,209$) and GSHP energy consumption is was 5,182 kWh (${\sigma}=1,164$). Second, residential energy consumption ranked highest in average energy usage, with at 45% of the total, followed by heating with at 30%, hot water supply with at 17% and cooling with at 6%. Third, the average energy independence rate is was 51.8%, the GFA (Gross gross floor area) criteria average energy consumption unit is was $48.7kWh/m^2yr$ (${\sigma}=10.1$), and the net energy consumption unit (except the energy yield of the PV systems) is was $24.7kWh/m^2yr$ (${\sigma}=8.8$).