• 제목/요약/키워드: Specific Point

검색결과 2,252건 처리시간 0.032초

평판휜-관 응축기의 수치 시뮬레이션 (Numerical Simulation of Plate Finned-Tubes Condenser)

  • 민묘식;최상경
    • 설비공학논문집
    • /
    • 제6권3호
    • /
    • pp.193-205
    • /
    • 1994
  • A simulation program of the plate finned-tubes condenser widely used in the air conditioning system was developed. The program took into account the variations of the flow properties and fluid friction factor of refrigerant, and the heat transfer coefficients of refrigerant and air sides. The program was applied to a copper tube condenser which has outside diameter of 10.05mm, inside diameter of 9.35mm, length of 5.20m and three rows arraied staggered. Simulation results were such that refrigerant was super-heated state from the entrance to the 0.14m point, two-phase flow from the 0.14m point to the 4.10m point, sub-cooled state from the 4.10m point to the outlet. The degree of sub-cooled was $6.1^{\circ}C$. The variations of refrigerant quality, temperature, pressure, velocity, specific enthalpy, specific volume and air temperature, tube temperature were showed.

  • PDF

Phase Shift Analysis and Phase Identification for Distribution System with 3-Phase Unbalanced Constant Current Loads

  • Byun, Hee-Jung;Shon, Sugoog
    • Journal of Electrical Engineering and Technology
    • /
    • 제8권4호
    • /
    • pp.729-736
    • /
    • 2013
  • Power grids are large complicated networks in use around. An absolute phase value for a particular unknown-phase line at a local site should be identified for the operation and management of a 3-phase distribution network. The phase shift for a specific point in the line, as compared with a phase reference point at a substation, must be within a range of ${\pm}60^{\circ}$ for correct identification. However, the phase shift at a particular point can fluctuate depending on the line constants, transformer wiring method, line length, and line amperage, etc. Conducted in this study is a theoretical formulation for the determination of phase at a specific point in the line, Simulink modeling, and analysis for a distribution network. In particular, through evaluating the effects of unbalanced current loads, the limitations of the present phase identification methods are described.

Uncertainty Assessment: Relative versus Absolute Point Dose Measurement for Patient Specific Quality Assurance in EBRT

  • Mahmood, Talat;Ibrahim, Mounir;Aqeel, Muhammad
    • 한국의학물리학회지:의학물리
    • /
    • 제28권3호
    • /
    • pp.111-121
    • /
    • 2017
  • Verification of dose distribution is an essential part of ensuring the treatment planning system's (TPS) calculated dose will achieve the desired outcome in radiation therapy. Each measurement have uncertainty associated with it. It is desirable to reduce the measurement uncertainty. A best approach is to reduce the uncertainty associated with each step of the process to keep the total uncertainty under acceptable limits. Point dose patient specific quality assurance (QA) is recommended by American Association of Medical Physicists (AAPM) and European Society for Radiotherapy and Oncology (ESTRO) for all the complex radiation therapy treatment techniques. Relative and absolute point dose measurement methods are used to verify the TPS computed dose. Relative and absolute point dose measurement techniques have a number of steps to measure the point dose which includes chamber cross calibration, electrometer reading, chamber calibration coefficient, beam quality correction factor, reference conditions, influences quantities, machine stability, nominal calibration factor (for relative method) and absolute dose calibration of machine. Keeping these parameters in mind, the estimated relative percentage uncertainty associated with the absolute point dose measurement is 2.1% (k=1). On the other hand, the relative percentage uncertainty associated with the relative point dose verification method is estimated to 1.0% (k=1). To compare both point dose measurement methods, 13 head and neck (H&N) IMRT patients were selected. A point dose for each patient was measured with both methods. The average percentage difference between TPS computed dose and measured absolute relative point dose was 1.4% and 1% respectively. The results of this comparative study show that while choosing the relative or absolute point dose measurement technique, both techniques can produce similar results for H&N IMRT treatment plans. There is no statistically significant difference between both point dose verification methods based upon the t-test for comparing two means.

요부.슬부 동태손상증후군에서의 동씨침 동기요법의 활용 (Dong-Qi Therapy of Dong-Si Acupuncture to Movement System Impairment Syndrome of Lumbar Spine and Knee)

  • 윤우석;박영재;박영배
    • Journal of Acupuncture Research
    • /
    • 제30권1호
    • /
    • pp.13-22
    • /
    • 2013
  • Objectives : The aim of this study was to show the application to add the Dong-Qi therapy of the Dong-Si acupuncture to exercise therapy of the movement system impairment syndrome(MSIS) and to determine the best acupuncture point for the Dong-Qi therapy. Methods : We reviewed Diagnosis and Treatment of Movement Impairment Syndrome and Movement System Impairment Syndromes Of The Extremities, Cervical and Thoracic Spines written by Sahrmann SA. to show the exercise therapy of the sort of MSIS. We reviewed complete works of Yang Wei Jie to show the acupuncture points of the Dong-Si acupuncture and the Dong-Qi therapy. Results : We showed the acupuncture point of the Dong-Si acupuncture by each type of MSIS based on the reference book of MSIS, the Dong-Si acupuncture. Also, we selected and tabulated the best possible acupuncture point of the Dong-Si acupuncture which could minimize a side effect of acupuncture during the therapeutic exercise by each type of MSIS. Conclusion : A specific acupuncture point of the Dong-Si acupuncture could be chosen for a specific MSIS therapeutic exercise. The best possible acupuncture point could be chosen when selecting an acupuncture point of the Dong-Si acupuncture.

무선 인터넷 환경에서 PDA를 이용한 웹 기반 POS 시스템의 설계 및 구현 (Design and Implementation of Web Based POS System using PDA in Wireless Internet Environment)

  • 신동헌;조수현;이준택;김영학
    • 한국콘텐츠학회논문지
    • /
    • 제3권1호
    • /
    • pp.47-57
    • /
    • 2003
  • POS(Point Of Sales) 시스템이란 매장에서 발생하는 판매시점의 모든 정보를 실시간으로 수집, 처리하여 각 부문별 정보를 종합, 분석, 평가할 수 있는 S/W와 H/W를 의미한다. 그러나 기존의 POS 시스템들은 대형 매장이나 할인점들을 대상으로 하여 고가의 전용 장비들을 이용하고 있어, 음식판매 전문매장에서 이를 도입해 사용하기에는 비용이나 규모 면에서 적합하지 않다. 따라서 본 논문에서는 별도의 전용 장비나 망을 구성하지 않고 PC와 PDA로 구성된 무선 인터넷 환경을 이용하여, 음식판매 전문매장에서도 사용할 수 있도록 하는 웹 기반의 POS시스템을 설계 및 구현하였다.

  • PDF

황제내경의 오수혈 임상 활용 연구 - 사용 빈도와 선혈을 중심으로 (A Study on the Clinical Application of Five-Transport-Points in Huangdineijing - Focused on Frequency of Application and Selection)

  • 김도훈;백유상
    • Korean Journal of Acupuncture
    • /
    • 제37권4호
    • /
    • pp.276-283
    • /
    • 2020
  • Objectives : In each section of Huangdineijing, we reviewed how the actual clinical application of Five-Transport-points was reflected and looked at the pattern of the application at the time. Methods : The contents related to Five-Transport-points in Huangdineijing were collected from each part, and analyzed. Results : There was a great difference in the number and contents of the clinical application of each Five-Transport-point for each 12 meridian, and only 28.3% of all Five-Transport-points had been related to clinical treatment. In addition, in specific applications, spring point, stream point, and sea point were used more often than well point, and Five-Transport-points between the same meridian or different meridians were used in combination as needed. Conclusions : Five-Transport-points described in Huangdineijing are intended to be operated within the overall framework structurally or functionally with a certain principle, but as a result of comprehensive analysis of specific examples of clinical application, there was a difference in the application between Five-Transport-points. This indicates that at the time of the establishment of Huangdineijing, which was the early stage of the development of Traditional East Asian Medicine, a variety of miscellaneous acupuncture methodologies were used in addition to those based on five elements principle.

Backplane processor의 HSTL 신호전달 특성 연구 (A Study on Signal Transmission Specific Property HSTL of Backplane Processor)

  • 김석환;류광렬;허창우
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국해양정보통신학회 2003년도 춘계종합학술대회
    • /
    • pp.355-358
    • /
    • 2003
  • 본 문서는 백프레인(backplane)에서 프로세서 HSTL(High-speed Transceiver Logic)의 데이터 전송 및 수신 특성을 알아보기 위해 HSPICE를 사용하여 시뮬레이션을 하였으며 Xilinx Virtex II XC2V FF896 FPGA를 이용하여 직접 제작 신호 전달특성을 분석하였다. PCB(Printed Circuit Board)는 FR-4를 사용하였으며 point to point 배선 길이에 대해 데이터 전송속도 특성을 시험하였고 구현 가능한 데이터 전송 및 수신 한계 속도에 대해 검토하였다. 시험결과 point to point 접속 신호 전송 및 수신 한계속도에 영향을 주는 것이 배선 길이와 주변 전기적 잡음이 중요한 역할을 함을 알 수 있었다.

  • PDF

Distinctive point extraction and recognition algorithm for counters for the various kinds of bank notes

  • Joe, Yong-won;An, Eung-seop;Lee, Jae-kang;Kim, Il-hwan
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 2002년도 ICCAS
    • /
    • pp.90.1-90
    • /
    • 2002
  • Counters for the various kinds of bank notes require high-speed distinctive point extraction and recognition for notes. In this paper we propose a new point extraction and recognition algorithm for bank notes. For distinctive point extraction we use a coordinate data extraction method from specific parts of a bank note representing the same color. The recognition algorithm uses a back-propagation neural network that has coordinate data input. The proposed algorithm is designed to minimize recognition time.

  • PDF

전자파 비흡수율(SAR) 측정용 전기장 프로브의 검파 전압 특성 (Characteristics of the Detection Voltages of an E-field Sensing Probe in SAR Measurement System)

  • 김윤명;이승배;김기회
    • 한국전자파학회논문지
    • /
    • 제16권2호
    • /
    • pp.217-221
    • /
    • 2005
  • 이동통신 기기로부터 복사되는 전자파가 인체에 흡수되는 에너지의 양은 모의 인체 내에서 전자파 비흡수율 [SAR(Specific Absorption Rate)]로 평가된다. RF 센싱 프로브의 Schottky 다이오드에 검출된 DC 전압은 높은 레벨에서 자승법칙(Square Law) 영역을 벗어나 선형성을 나타낸다. Square Law Region을 벗어난 직선 영역의 검파는 적절한 DCP(Diode Compression Point) 값으로 검 파된 전압을 보상하여야 한다. 적절한 보상에 의한 한 점에서의 SAR 값은 200 W/kg까지 측정할 수 있다.

인돌렌-메탄올 대체연료의 연료 특성과 엔진성능에 관한 연구 (A Study on the Fuel Characteristics and Engine Performance of Indolene - Methanol Alternative Fuel)

  • 이민호;오율권;차경옥
    • 한국분무공학회지
    • /
    • 제9권4호
    • /
    • pp.9-16
    • /
    • 2004
  • A study of the propeny and performance effect of Indolene - Methanol Plus High Alcolhols (MPHA) has been completed. This study invested the measurement of fuel properties and performance parameters. The fuel properties investigated are distillation characteristics, heating valuer flash point, specific gravity and water tolerance. The performance parameters measured are minimum advance for best torque (MBT) spark timing, power output. The alcohol concentration was varied from 0 to 100 percent by volume in clear Indolene. The measurement of fuel properties indicated that, in general, Indolene - MPHA blends have higher water tolerance, similar specific gravity, similar flash point and different distillation characteristics compared to Indolene - Methanol blends. The performance parameters were measured using a single cylinder spark ignition engine at different compression ratios. The results of the performance measurements indicated that Indolene - MPHA blends have a higher MBT spark advance, similar power output.

  • PDF