• 제목/요약/키워드: V/f control

검색결과 397건 처리시간 0.033초

회전교차로의 서비스수준 기준 정립 연구 (A Study of Level of Service Criteria for Roundabouts)

  • 김응철;지민경
    • 대한교통학회지
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    • 제27권1호
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    • pp.7-16
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    • 2009
  • 국내에서 제정된 도로용량편람(2001)은 무통제 교차로와 양방향정지 교차로의 서비스수준 분석 방법만을 제시하고 있으며, 회전교차로 서비스수준 분석 방법에 대해서는 다루고 있지 않을 뿐만 아니라, 회전교차로라는 명칭조차 포함하고 있지 않은 실정이다. 따라서 본 연구에서는 회전교차로를 위한 적정한 효과척도를 선정하고, 시뮬레이션 분석을 통하여 서비스수준의 기준을 정립하는 것을 목적으로 하였다. 이를 위하여 우선 적절한 효과척도(MOE)를 선정하는 방법을 고찰하고, 서비스수준을 개발하는 수순으로 연구를 수행하였다. 회전교차로에 적용할 효과척도로 진입교통량, v/c비, 평균차량지체로 선정되었으며, 선정된 효과척도를 토대로 VISSIM을 이용하여 서비스수준의 기준을 정립하였다. 연구결과, 지방지역 1차로 회전교차로에서의 서비스수준 F의 진입교통량은 1,700pcph이며, 평균차량지체는 18초로 분석되었다. 서비스수준 A에 대해서 진입교통량은 700pcph이며, 이때 평균차량지체는 3초, v/c비는 0.41로 분석되었다. 지방지역 2차로 회전교차로는 서비스수준 F의 진입교통량은 2,900pcph이며, 평균차량지체는 31초로 분석되었다. 서비스수준 A인 경우 진입교통량은 1,500pcph이며, 이때 평균차량지체는 8초, v/c비는 0.52로 분석되었다.

동전기 정화기술을 이용한 Zn, Ni, F 복합오염 토양의 정화 (Electrokinetic Remediation of Soil Contaminated with Zn, Ni and F)

  • 조정민;류병곤;박성우;김경조;백기태
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제14권1호
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    • pp.36-43
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    • 2009
  • Zn, Ni 및 불소로 복합 오염된 토양의 정화를 위해서 동전기 정화(Electrokinetic remediation)기술을 적용하였다. 토양에서 탈착된 불소는 음이온 형태이고, Zn, Ni은 양이온으로 존재하기 때문에 간극수가 이동하는 전기삼투(electro-osmosis)와 이온이 이동하는 전기이동(electro-migration)의 두 가지 기작에 의해 제거되는 경향이 달랐다. 불소는 알칼리 조건에서 토양으로부터의 탈착이 증가하고, Zn과 Ni은 산성조건에서 탈착이 증가된다. 두 가지 탈착 특성이 다른 오염물질을 순차적 pH조절을 통해 효과적으로 제어할 수 있었다. 정전압 하에서의 영향을 평가하기 위하여 2V/cm를 적용하여으며, 2주간의 실험을 통해 Zn은 20.5%, Ni은 2.5%, 불소는 57.4% 제거되었다. Zn과 Ni의 제거율은 낮았으나 토양 ph조절을 통해 이동 가능함을 확인하였다. 토양 pH조절을 통하여 특성이 다른 복합오염물질을 동전기 정화 기술로 제거할 수 있을 것으로 사료된다.

Investigation of Genetic Diversity of Fusarium oxysporum f. sp. fragariae Using PCR-RFLP

  • Kim, Ji-Su;Kang, Nam Jun;Kwak, Youn-Sig;Lee, Choungkeun
    • The Plant Pathology Journal
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    • 제33권2호
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    • pp.140-147
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    • 2017
  • Fusarium wilts of strawberry, caused by Fusarium oxysporum f. sp. fragariae, is a serious soil-borne disease. Fusarium wilt causes dramatic yield losses in commercial strawberry production and it is a very stubborn disease to control. Reliable chemical control of strawberry Fusarium wilt disease is not yet available. Moreover, other well-known F. oxysporum have different genetic information from F. oxysporum f. sp. fragariae. This analysis investigates the genetic diversity of strawberry Fusairum wilt pathogen. In total, 110 pathogens were isolated from three major strawberry production regions, namely Sukok, Hadong, Sancheong in Gyeongnam province in South Korea. The isolates were confirmed using F. oxysporum f. sp. fragariae species-specific primer sets. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses were executed using the internal transcribed spacer, intergenic spacer, translation elongation factor1-${\alpha}$, and ${\beta}$-tubulin genes of the pathogens and four restriction enzymes: AluI, HhaI, HinP1I and HpyCH4V. Regarding results, there were diverse patterns in the three gene regions except for the ${\beta}$-tubulin gene region. Correlation analysis of strawberry cultivation region, cultivation method, variety, and phenotype of isolated pathogen, confirmed that genetic diversity depended on the classification of the cultivated region.

좌회전 감응신호제어방법 개발에 관한 연구 (Study on Development of the Left-Turn Actuated Signal Control Method)

  • 김수희;오영태;이철기;이환필;최진호
    • 한국ITS학회 논문지
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    • 제10권3호
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    • pp.9-15
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    • 2011
  • 실시간신호제어시스템(COSMOS)에서 좌회전 감응신호제어 시 U-Turn 차량을 고려하지 않아 좌회전 차로가 U-turn 공용차로로 운영될 경우, U-Turn차량의 혼입으로 인해 일반적인 좌회전 차량의 통행특성과 달라지므로 최소녹색시간 및 진행연장시간의 증가에 따른 좌회전 조기종결의 문제가 종종 발생하고 있다. 이러한 문제를 해결하기 위하여, 본 연구에서는 좌회전 감응신호제어용 검지기(좌회전 정지선 후방 12m위치)를 U-Turn 허용차선 시작부분으로 이격(Set-Back)하고, 상기의 문제를 해결하는 좌회전 감응 신호제어방법을 개발하였다. 또한, 상기 개발방법의 적용성 평가를 위하여 TRANSYT-7F, VISSIM을 이용한 모의실험을 수행하였으며, 교통상황(포화, 근포화, 비포화), 신호제어 방법(고정식 신호제어, COSMOS 좌회전 감응신호제어, 개발 방법의 좌회전 감응신호제어), U-Turn 비율(10, 20, 30%)에 따라 다양하게 수행하였다. 상기의 모의 실험결과에 의하면, 포화(V/C = 1.0), 근포화(V/C = 0.8)교통상황에서 개선효과가 있는 것으로 분석되었다.

Extracellular ATP Induces Apoptotic Signaling in Human Monocyte Leukemic Cells, HL-60 and F-36P

  • Yoon, Mi-Jung;Lee, Hae-Jin;Kim, Jae-Hwan;Kim, Dong-Ku
    • Archives of Pharmacal Research
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    • 제29권11호
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    • pp.1032-1041
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    • 2006
  • Extracellular adenosine 5'-triphosphate (ATP) affects the function of many tissues and cells. To confirm the biological activity of ATP on human myeloid leukemic cells, F-36P and HL-60, cells were treated with a variety of concentrations of ATP. The stimulation with extracellular ATP induced the arrest of cell proliferation and cell death. from the analysis of Annexin-V staining and caspase activity by flow cytometry. The Annexin-V positive cells in both cell lines were dramatically increased following ATP stimulation. The expression of P2 purinergic receptor genes was confirmed, such as P2X1, P2X4, P2X5, P2X7 and P2Y1, P2Y2, P2Y4, P2Y5, P2Y6, P2Y11 in both leukemic cell lines. Interestingly, ATP induced intracellular calcium flux in HL-60 cells but not in F-36P cells, as determined by Fluo-3 AM staining. Cell cycle analysis revealed that ATP treatment arrested both F-36P and HL-60 cells at G1/G0. Taken together, these data showed that extracellular ATP via P2 receptor genes was involved in the cell proliferation and survival in human myeloid leukemic cells, HL-60 and F-36P cells by the induction of apoptosis and control of cell cycle. Our data suggest that treatment with extracellular nucleotides may be a novel and powerful therapeutic avenue for myeloid leukemic disease.

근위축성 측삭 경화증의 하 운동 신경원 과흥분성: 운동유발전위를 이용한 분석 (Lower Motor Neuron Hyperexcitability in Amyotrophic Lateral sclerosis: Analysis Using Motor Evoked Potentials)

  • 배종석;홍석찬;김민기;김병준
    • Annals of Clinical Neurophysiology
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    • 제5권1호
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    • pp.21-26
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    • 2003
  • Background & Objectives: Hyperexcitablity of motor system is a well-established characteristic pathophysiologic finding of amyotrophic lateral sclerosis (ALS). Whereas little is known about the source of excitability according to the progression of the disease. We evaluated the excitability and its source in advanced ALS patients using transcranial magnetic stimulation (TMS). Meterial & Methods: Motor evoked potentials (MEP) by TMS were recorded for abductor pollicis brevis muscles in 20 patients, 11 men and 9 women, with ALS. Mean age was $54.2{\pm}12.1years$, and mean disease duration was $13.9{\pm}13.4years$. Serial magnetic stimulations were applied to get the parameters; excitability threshold (ET), amplitude and latency of MEP. We also had a facilitated MEP (fMEP). Results: The parameters were analyzed according to the clinical settings. ET was higher in ALS(mean $63.5{\pm}18.1$) than normal control (mean $46.0{\pm}8.4$, p<0.01). Amplitudes of MEP were reduced in ALS ($2.6{\pm}3.6mV$; control $6.5{\pm}3.1mV$, p<0.01). Duration of the disease and ET showed significant inverse correlation (Spearson correlation coefficient = -0.57, p<0.01). Duration of the disease and fMEP/MEP ratio showed less but also significant inverse correlation (Spearson correlation coefficient, r = -0.52, p < 0.05). Conclusions: Lower ET in advanced ALS patients, in spite of decreased fMEP/MEP ratio, may indicate the hyperexcitability of lower motor neurons in these patients. This study suggests that lower motor neurons is hyperexcitable due to upper motor neuron dysfunction at advanced stage.

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Dynamic Performance Analysis for Different Vector-Controlled CSI- Fed Induction Motor Drives

  • Mark, Arul Prasanna;Irudayaraj, Gerald Christopher Raj;Vairamani, Rajasekaran;Mylsamy, Kaliamoorthy
    • Journal of Power Electronics
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    • 제14권5호
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    • pp.989-999
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    • 2014
  • High-performance Current Source Inverter (CSI)-fed, variable speed alternating current drives are prepared for various industrial applications. CSI-fed Induction Motor (IM) drives are managed by using different control methods. Noteworthy methods include scalar Control (V/f), Input-Output Linearization (IOL) control, Field-Oriented Control (FOC), and Direct Torque Control (DTC). The objective of this work is to compare the dynamic performance of the aforementioned drive control methods for CSI-fed IM drives. The dynamic performance results of the proposed drives are individually analyzed through sensitivity tests. The tests selected for the comparison are step changes in the reference speed and torque of the motor drive. The operation and performance of different vector control methods are verified through simulations with MATLAB/Simulink and experimental results.

Screening for In Vitro Antifungal Activity of Soil Bacteria Against Plant Pathogens

  • Chang, Sung-Hwan;Lee, Jung-Yeop;Kim, Ki-Deok;Hwang, Byung-Kook
    • Mycobiology
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    • 제28권4호
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    • pp.190-192
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    • 2000
  • Antifungal bacteria for biological control of plant diseases or production of novel antibiotics to plant pathogens were isolated in 1997 from various soils of Ansung, Chunan, Koyang, and Paju in Korea. Sixty-four bacterial strains pre-screened from approximately 1,400 strains were tested on V-8 juice agar against eight plant pathogenic fungi using in vitro bioassay technique for inhibition of mycelial growth. Test pathogens were Alternaria mali, Colletotrichum gloeosporioides, C. orbiculare, Fusarium oxysporum f. sp. cucumerinum, F. oxysporum f. sp. lycopersici, Magnaporthe grisea, Phytophthora capsici, and Rhizoctonia solani. A wide range of antifungal activity of bacterial strains was found against the pathogenic fungi, and strain RC-B77 showed the best antifungal activity. Correlation analysis between inhibition of each fungus and mean inhibition of all eight fungi by 64 bacterial strains revealed that C. gloeosporioides would be best appropriate for detecting bacterial strains producing antibiotics with potential as biocontrol agents for plant pathogens.

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Free vibration analysis of damaged composite beams

  • Cunedioglu, Yusuf;Beylergil, Bertan
    • Structural Engineering and Mechanics
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    • 제55권1호
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    • pp.79-92
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    • 2015
  • In this study, free vibration analyses of symmetric laminated cantilever and simply supported damaged composite beams are investigated by using finite element method (FEM). Free vibration responses of damaged beams are examined using Euler Bernoulli beam and classical lamination theories. A computer code is developed by using MATLAB software to determine the natural frequencies of a damaged beam. The local damage zone is assumed to be on the surface lamina of the beam by broken fibers after impact. The damaged zone is modeled as a unidirectional discontinuous lamina with $0^{\circ}$ orientations in this study. Fiber volume fraction ($v_f$), fiber aspect ratio ($L_f/d_f$), damage length ($L_D$) and its location (${\lambda}/L$), fiber orientation and stacking sequence parameters effects on natural frequencies are investigated. These parameters are affected the natural frequency values significantly.

Characterization of F2 Progenies of Wound Minus Arabidopsis Mutant Crossed with Wild Type Plant

  • Park, Sanggyu
    • Journal of Applied Biological Chemistry
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    • 제43권1호
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    • pp.12-17
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    • 2000
  • To understand the signal transduction pathway that leads to the activation of the wound-inducible proteinase inhibitor II (pin2) promoter. $F_2$ progenies of wound (-) mutant crossed with wild-type Arabidopsis plants were biochemically and genetically characterized. Wound (-) mutant was derived from transgenic Arabidopsis plants containing bacterial cytosine deaminase gene under the control of pin2 promoter. The cytosine deaminase assays indicated that wound (-) mutant is a dominant inhibitor of wound-inducibility as only 3 of the $20F_2$ progenies showed cytosine deaminase (CDase) activity, To construct a structural map of the wound (-) mutant chromosomal regions, cleaved, amplified polymorphic sequences (CAPS) markers that cover all Chromosomes were used. Chromosomal regions covered by three different CAPS markers could be candidates for further fine mapping of the location of the wound (-) mutation. g4026, RGA1 and ASA1 located at 84.9 on recombinant inbred (RI) map of chromosome I, at 1.75 on RI map of chromosome II, and 18.35 on RI map of chromosome V, respectively.

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