• 제목/요약/키워드: K-point

검색결과 28,023건 처리시간 0.053초

태양전지 모듈 구조와 바이패싱 동작 포인트의 관계 분석 (The study on the relationship between structure of PV module and bypassing point)

  • 지양근;공지현;강기환;유권종;안형근;한득영
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
    • /
    • pp.70-70
    • /
    • 2010
  • Until recently. the study about bypass diode has been limited to theoretical study. but, in this paper, We study on the relationship between structure of PV module and Bypassing point by simulation software(Pspice). We expected the design on the PV module has an effect on bypassing point. So, we designated the two kind of experiment with PV modules. One of the experiment is on the relationship between the number of rows and Bypassing point on the PV modules, the other experiment is on the relationship between the number of groups(two columns) on the PV modules.(around 50Wp, 100Wp, 150Wp, 200WP) As the result, the more increase the number of rows, bypassing point is faster. And the more increase the number of groups in more than 3 groups, bypassing point is faster more than case of increasing the rows.

  • PDF

Traditional Software Development for WLAN Propagation Model

  • Ibrahim Anwar Hassan;Ismail Mahamod;Jumari Kasmiran;Kiong Tiong Sieh
    • Journal of Electrical Engineering and Technology
    • /
    • 제2권1호
    • /
    • pp.123-128
    • /
    • 2007
  • SPWPM traditional software development is surveyed and essential problems are investigated on the basis of system wireless link considerations. This paper presents the current state software planning tools for wireless LAN link optimization. The software directory is based on combination of MatLab and MapInfo software and measurement which gives the best grouping parameters to build up the software development. Among the requirements assumed, the WLAN site selections must be Line-of-sight (LOS) or near line of sight (NLOS) field strength prediction for either point to point or point to multi points. The results obtainable the out put of the program include two-dimensional (2D) and three dimensional (3D) plots for creating the link; design parameters through GUI representing the height and location for each antenna is depending on K-factor of the area and transmit antenna location.

Improved Global Maximum Power Point Tracking Method Based on Voltage Interval for PV Array under Partially Shaded Conditions

  • Ding, Kun;Wang, Xiang;Zhai, Quan-Xin;Xu, Jun-Wei;Zhang, Jing-Wei;Liu, Hai-Hao
    • Journal of Power Electronics
    • /
    • 제14권4호
    • /
    • pp.722-732
    • /
    • 2014
  • The power-voltage (P-V) curve of photovoltaic (PV) arrays connected in parallel to bypass diodes would have several local maximum power points (LMPP) under partial shading conditions (PSC). Conventional maximum power point tracking (MPPT) methods fail to search for the global maximum power point (MPP) because the searched peak point may remain at the LMPP on the P-V curve under PSC. This study proposes an improved MPPT algorithm to ensure that PV arrays operate at global maximum power point (GMPP) under PSC. The proposed algorithm is based on a critical study and a series of observations of PV characteristics under PSC. Results show the regularity of voltage interval between LMPPs. The algorithm has the advantages of rapidly reaching GMPP, maintaining stability, and recovering GMPP quickly when the operating condition changes. Simulation and experimental results demonstrate the feasibility of the proposed algorithm.

삼림파괴로 인한 미기후 환경변화에 관한 관측적 연구 (An Observational Study on the Change of Micro-meteorological Environment due to Deforestation)

  • 임정섭;이부용;김해동;김학윤;황수진
    • 한국지구과학회지
    • /
    • 제30권2호
    • /
    • pp.185-195
    • /
    • 2009
  • 이 연구의 목적은 삼림파괴로 유발되는 몇 가지 기상학적 요소의 변화를 관측을 통해서 조사하였다. 이 연구를 위해서 기상관측 장치를 숲이 파괴된 곳과 숲이 보존되어 있는 곳에 설치하여 1년간(2006. 12.-2007. 12) 연속 관측하였다. 이 후로 숲이 파괴된 지점을 point 1 그리고 숲이 보존되어 있는 지점을 point 2라고 지칭하기로 한다. 이 연구에서는 여름철에 강우가 있은 다음 날부터 1주일 동안 관측된 두 지역의 자료를 비교 분석하였다. 관측 자료의 분석을 통하여 야간에는 두 지역의 온도분포가 비슷하였지만, 낮에는 지점 1에서 관측된 기온이 지점 2보다 약 $1.5^{\circ}C$ 높게 나타났다는 것을 확인할 수 있었다. 하지만 야간에는 두 지점간의 차이가 작았다. 상대습도도 숲의 보존지역(지점2)에서 높게 나타났는데, 그 차이는 한낮에 10%정도에 이르렀다. 지표와 지중 15cm 깊이의 온도도 두 지역 사이에 큰 차이를 보였다. 그 차는 낮에 크고 야간에는 작았는데, 대체로 지점 1에서의 값이 $3-10^{\circ}C$ 더 높게 나타났다. 토양수분은 지점에서 7.1%, 지점 2에서 19.5%로 나타나서 지점 2에서의 토양 수분이 지점 1보다 훨씬 높았다. 두 지점에서 풍향은 주로 북서-북동풍으로 거의 차이가 없었지만, 풍속은 지점 2(0.3m/s)에서 지점 1(0.5m/s)보다 작게 관측되었다. 이러한 관측 자료를 바탕으로 두 지점 사이에 존재하는 열수지적 차이에 대해서도 분석하였다.

Inferolateral Entry Point for C2 Pedicle Screw Fixation in High Cervical Lesions

  • Lee, Kwang-Ho;Kang, Dong-Ho;Lee, Chul-Hee;Hwang, Soo-Hyun;Park, In-Sung;Jung, Jin-Myung
    • Journal of Korean Neurosurgical Society
    • /
    • 제50권4호
    • /
    • pp.341-347
    • /
    • 2011
  • Objective : The purpose of this retrospective study was to evaluate the efficacy and safety of atlantoaxial stabilization using a new entry point for C2 pedicle screw fixation. Methods : Data were collected from 44 patients undergoing posterior C1 lateral mass screw and C2 screw fixation. The 20 cases were approached by the Harms entry point, 21 by the inferolateral point, and three by pars screw. The new inferolateral entry point of the C2 pedicle was located about 3-5 mm medial to the lateral border of the C2 lateral mass and 5-7 mm superior to the inferior border of the C2-3 facet joint. The screw was inserted at an angle $30^{\circ}$ to $45^{\circ}$ toward the midline in the transverse plane and $40^{\circ}$ to $50^{\circ}$ cephalad in the sagittal plane. Patients received followed-up with clinical examinations, radiographs and/or CT scans. Results : There were 28 males and 16 females. No neurological deterioration or vertebral artery injuries were observed. Five cases showed malpositioned screws (2.84%), with four of the screws showing cortical breaches of the transverse foramen. There were no clinical consequences for these five patients. One screw in the C1 lateral mass had a medial cortical breach. None of the screws were malpositioned in patients treated using the new entry point. There was a significant relationship between two group (p=0.036). Conclusion : Posterior C1-2 screw fixation can be performed safely using the new inferolateral entry point for C2 pedicle screw fixation for the treatment of high cervical lesions.

NFC 지적기준점과 지적정보어플리케이션 적용에 대한 효용성 분석 (The Efficiency Analysis of using NFC Cadastral Control Point and a Cadastral Information Application)

  • 김성준;이종달;김성훈;배재열
    • 대한공간정보학회지
    • /
    • 제22권1호
    • /
    • pp.31-39
    • /
    • 2014
  • 현재 IT기술의 발전과 스마트폰의 대중화로 정보제공 방식 및 활용성이 점차 진화되고 있다. 특히 스마트폰을 통한 실시간 정보제공 및 활용 측면에서는 다양한 어플리케이션들이 개발되고 있으며 사용되고 있다. 최근 기준점정보의 효율적인 관리와 제공을 위한 정보제공 방안들이 연구 및 적용되고 있다. 본 연구에서는 울산광역시 동구에 설치 활용되고 있는 QR코드 지적기준점을 개선한 NFC 지적기준점과 어플리케이션을 개발 및 적용해 보았다. 또한 기존 기준점을 이용한 측량 방식과 NFC 지적기준점을 이용한 측량 방식을 비교 및 시험하여 두 방식에 대한 효용성을 분석해 보았다. 두 방식의 적용결과 외부환경에 따른 손상과 활용성 측면에서는 NFC 지적기준점이 장점이 있으며 특히 인식방식에 따른 편의성 측면과 인식률 및 인식속도에서는 NFC 방식이 우수한 것을 알 수 있었다. 또한 QR코드 지적기준점과 NFC 지적기준점 정보를 함께 적용 가능한 지적정보 어플리케이션을 개발하여 기존 기준점 성과를 이용한 측량방식과 비교한 결과 지적정보 어플리케이션이 현장답사 시간이 절약되고 기준점 성과 정보취득 시간이 짧고 간편해 효용성이 높은 것으로 분석되었다. 향 후 정부차원의 통합적인 지적기준점 관리와 정보제공을 위한 어플리케이션이 개발된다면 전국의 지적기준점 및 관련 정보를 통합관리가 가능할 것으로 사료되며, 효과적인 정보서비스를 이용할 수 있을 것으로 기대된다.

혈류역학을 이용한 촌구와 인영의 특성비교 (Comparative study of pulse point using hemodynamics)

  • 신상훈;박대훈;박영재;박영배
    • Journal of Acupuncture Research
    • /
    • 제21권5호
    • /
    • pp.241-248
    • /
    • 2004
  • Objectives : The purpose of this study is to examine the hemodynamic characteristics of pulse point. Methods : The computational analysis algorithms of arterial tree system was derived. In order to investigate the effect of internal organ on the pulse point, the diameter of celiac artery was reduced by half. Results : The sensitivity of flow change at the Inyoung(Renying) is better than that of the Chongu(Cunkou). but the Inyoung was worse than the Chongu in the point of the left and right symmetry. The pressure changes at the Inyoung and the Chongu were in the similar range. Conclusions : It was found from the result that the Chongu shows the more symmetrical hemodynamic characteristics than the Inyoung.

  • PDF

Controller Area Network을 이용한 자동차용 전동거울 시스템 구현 (Realization of automobile electromotive mirror system using Controller Area Network(CAN Protocol))

  • 윤상진;조용석;이종성;박기헌
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2002년도 하계학술대회 논문집 D
    • /
    • pp.2234-2236
    • /
    • 2002
  • In this paper, realized an automation system that applies the automobile electromotive mirror using CAN(Controller Area Network : ISO l1898). CAN is being used mainly in ECUs (Electronic Control Units) connection of control system or automobile inside. And it has high reliability in the various network protocol. To be realized position system, Automobile Electro mirror, has a strong point that estabilishment e decrease and ease of maintenance it compare PPP(Point-to-point) method of existed. The realization composed of three portions. One Input Slave Con which accept a user's input, another Output Slave Co which drove it makes the motor of electromotive mirr other Master Controller which interfacing the two Controller. Automobile electromotive mirror realized time system that will be able to minize the delay t point of time user's input until output point of time mirror.

  • PDF

Pulsed Radiofrequency Treatment of Pain Relieving Point in a Soft Tissue

  • Lee, Jeong-Soo;Yoon, Kyung-Bong;Kim, In-Ki;Yoon, Duck-Mi
    • The Korean Journal of Pain
    • /
    • 제24권1호
    • /
    • pp.57-60
    • /
    • 2011
  • Pulsed radiofrequency (PRF) treatment of nervous tissue has been proposed as a less neurodestructive technique alternative to continuous RF heat lesioning. Recently, clinical reports using PRF have shown favorable effects in the treatment of a variety of focal pain areas, even in non-nervous tissues; however, the mechanism of effect underlying this treatment to non-nervous tissue remains unclear. We report the case of a 67-year-old male who presented with pain reliving point in the posterior neck. The patient had pain in the posterior neck for 3 years. The pain subsided with pressure applied to a point in the posterior neck. There were no specific abnormal findings on laboratory testing and radiologic examinations. After PRF treatment to the pain-relieving point, he had pain relief which lasted more than 5 months.

피부 저항점 탐지기를 사용한 근근막 통증 유발점의 진단 (The Use of Skin Resistance Point Finder for the Diagnosis of Myofascial Trigger Points)

  • 강미숙;홍정은;임영진;이상철
    • The Korean Journal of Pain
    • /
    • 제12권2호
    • /
    • pp.195-199
    • /
    • 1999
  • Background: At present, there is no reliable objective test for the diagnosis of myofascial trigger points (MFTP). We evaluated the usefulness of skin resistance point finder for the diagnosis of MFTP. Methods: 40 subjects with clinical MFTPs at the upper trapezius muscle were included in this study. Using skin resistance point finder (UNIQUE S-2010$^{(R)}$, Seik medical, Korea), we tried to find out the point of low skin resistance. At three different current level, sensitivity and specificity of this method for the diagnosis of clinically identified MFTP was evaluated. Pressure threshold for pain of low skin resistance point was measured using Pressure Threshold Meter$^{(R)}$ (Pain Diagnostics and Thermography, U.S.A.). 3 groups of point detected at different current were compared in mean pressure threshold. Results: Fixed single current of skin resistance point finder showed variable sensitivity and specificity. But, by adjusting current level, skin resistance point finder detected all of 40 clinically identified MFTPs. Although it is partially statistically significant, the mean pressure threshold of points detected at high current was high. Conclusion: Skin resistance finder can be used as objective diagnostic tool of MFTPs. There is possibility that it can be useful in evaluating treatment effect. However, more investigation is necessary.

  • PDF