• 제목/요약/키워드: Effective point of measurement

검색결과 267건 처리시간 0.031초

원통형 전리함의 유효 측정점에 관한 실험적 연구 -의료용 전자선을 중심으로- (The Experimental Study of the Effective Point of Measurement for Cylindrical Ion Chamber -For Medical Electron Beams-)

  • 이병용;최은경;장혜숙;홍석민;이명자;전하정
    • 한국의학물리학회지:의학물리
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    • 제2권2호
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    • pp.155-160
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    • 1991
  • 전자선 측정에 사용되는 원통형 전리함의 유효 측정점 깊이에 관한 연구를 하였다. 물팬톰 속에서 Markus 평판형 전리함을 사용하여 여러 에너지(전자선 6MeV 및 9MeV, 12MeV, 20MeV) 방사선의 선량 백분율을 구하고, 이 값을 기준으로 하여 원통형 전리함으로(PW233643 내경 5.5mm 및 PR-05P 내경 4mm, PM30 내경 15mm) 구한 선량 백분율과 비하여 선량 백분율 곡선의 변위를 유효 측정점으로 계산하였다. 이 결과 전자선에서는 0.4~0.6r 만큼, $^{60}$Co 감마선에서는 0.3~0.7r 만큼 표면쪽으로 이동한 값을 측정점으로 정하여야 하는 것을 알았다.

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CAD/CAM/CAI 통합에 기초한 자유곡면의 On-Machine Measurement : II. 측정계획 수립 (On-Machine Measurement of Sculptured Surfaces Based on CAD/CAM/CAI Integration : II. Inspection Planning Strategy)

  • 조명우;김진섭;서태일;조재형
    • 한국정밀공학회지
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    • 제16권12호
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    • pp.109-118
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    • 1999
  • The objective of this research is to develop an effective inspection planning strategy for sculpture surfaces in OMM(On-Machine Measurement) process. As a first step, effective measuring point locations are determined to obtain optimum results for given sampling numbers. Two measuring point selection methods are suggested in this study based on newly proposed CAD/CAM/CAI integration concept: (1) by the prediction of cutting errors, (2) by considering cutter contact points to avoid the measurement errors caused by cusps. As a next step, the TSP(Traveling Salesman Problem)algorithm is applied to minimize the probe moving distance. Appropriate simulations and experiments are performed to verify the proposed inspection planning strategy in this study, and the results are analyzed.

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The Suggestion of Effective Measurement Techniques for Positioning Under Poor GPS Reference Network Condition

  • Park, Joon-Kyu;Jung, Kap-Yong
    • 한국측량학회지
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    • 제31권6_2호
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    • pp.539-547
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    • 2013
  • This research is suggesting the most effective positioning method for GPS based positioning when no GPS reference point is available in the neighborhood. For this purpose, we carried out positioning of the IGS realtime observatories in Australia in various conditions. According to the research, we were certainly assured the one reference point with a short baseline length is more effective for differential positioning than multiple reference points with a long baseline distance beyond 1,000km and suggested the precise point positioning based positioning method can be an excellent substitute when no reference point is available around an unknown point. The research result may be used as the basic data for accurate positioning in poor reference point environments, especially in Antarctica.

Multi-point displacement monitoring of bridges using a vision-based approach

  • Ye, X.W.;Yi, Ting-Hua;Dong, C.Z.;Liu, T.;Bai, H.
    • Wind and Structures
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    • 제20권2호
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    • pp.315-326
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    • 2015
  • To overcome the drawbacks of the traditional contact-type sensor for structural displacement measurement, the vision-based technology with the aid of the digital image processing algorithm has received increasing concerns from the community of structural health monitoring (SHM). The advanced vision-based system has been widely used to measure the structural displacement of civil engineering structures due to its overwhelming merits of non-contact, long-distance, and high-resolution. However, seldom currently-available vision-based systems are capable of realizing the synchronous structural displacement measurement for multiple points on the investigated structure. In this paper, the method for vision-based multi-point structural displacement measurement is presented. A series of moving loading experiments on a scale arch bridge model are carried out to validate the accuracy and reliability of the vision-based system for multi-point structural displacement measurement. The structural displacements of five points on the bridge deck are measured by the vision-based system and compared with those obtained by the linear variable differential transformer (LVDT). The comparative study demonstrates that the vision-based system is deemed to be an effective and reliable means for multi-point structural displacement measurement.

3차원 영상처리를 이용한 암반 사면의 절리 측정에 관한 연구 (Measurement of Rock Slope Joint using 3D Image Processing)

  • 이승호;황영철;심석래;정태영
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 춘계 학술발표회 논문집
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    • pp.854-861
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    • 2005
  • Studied accuracy and practical use possibility of joint measurement that using 3D laser scanner to rock slope. Measured joint of Rock slope and comparison applied 3 dimension laser scanner and clinometer. 3D laser scanning system preserves on computer calculating to 3 dimension coordinate scaning laser to object. and according to laser measurement method of interior, produce correct vector value from charge-coupled device(CCD) or laser reciver and telegram register and time measuring equipment. Create of object x, y, z point coordinates to 3 dimension space of computer. Such 3 dimension point datum (Point Clouds) forms relocate position informations that exist to practical space to computer space. Practical numerical values related between each other. Compared joint distribution and direction that measured by laser scanner and clinometer. By the result, Distribution of joint projected almost equally. Could get more joint datas by measurement of 3 dimension scanner than measured by clinometer. Therefore, There is effect that objectification of rock slope investigation data, shortening of investigation periods, investigation reduction of cost. could know that it is very effective method in joint measuring.

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NPE법을 이용한 절연재료의 유효열확산계수의 과도측정에 관한 연구 (A Study on the Transient Measurement of the Effective Thermal Diffusivity of Insulation Materials by NPE Method)

  • 임동주;배신철
    • 설비공학논문집
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    • 제2권3호
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    • pp.243-255
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    • 1990
  • The objective of this study is to present an efficient measurement method of the effective thermal diffusivity for the fibrous insulation material. The non-linear parameter estimation (NPE) method is adapted for this analysis because of its accuracy and its results are compared with those by other direct methods such as CTP, CHP and STD method. A experimental system is constructed with bell-jar vaccum chamber, diffusion pump, tube type furnace, control unit and data acquisition system included with A/D converter and IBM XT/AT personal computer. The typical results obtained from this study are as follows; 1) NPE method can be recommended as an useful and accurate method to measure the effective thermal diffusivity of insuation material because it is shown that the measurement error compared with those by other direct methods is reduced for standard material, NBS-1450b. 2) NPE method can minimize the effects of ill-measured temperature due to external disturbance, because the final value is found by point to point estimating. 3) NPE method dose not depend on the kinds of heat flux, since the surfac temperature are used to estimate the thermal diffusivity. 4) With NPE method, compared with the steady state method, a measuring time and a sample size could be reduced.

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정보시스템 신뢰성 향상을 위한 위험점수 측정모델 연구 (A Risk Point Measuring Model for Improvement of the Information System Reliability)

  • 조두호;서장훈
    • 대한안전경영과학회지
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    • 제7권3호
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    • pp.47-61
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    • 2005
  • Many researchers have proved that risk measurement of information systems is a very effective tool for improving confidence of information systems. However, information system risk in Korea still includes many subjective judgements. This study deals with applying a quantitative model to improve risk measurement of information system quality. First of all, we have come up with solutions to improve the evaluation efficiency on risk measurement. We have merged the risk guidelines of COBIT and CMM, and developed a quantified evaluation scheme that call by risk point. We have proved the validity of this model by interviews with experts and by case studies.

Scanned point detecting method(SPDM)에 의한 플라즈마 디스플레이 패널의 828nm 광에 대한 3차원 측정과 해석 (The three-dimensional measurement and analysis for 828nm light emitted from plasma display panel by scanned point detecting method(SPDM))

  • 최훈영;정재완;이승걸;이석현
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 하계학술대회 논문집
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    • pp.284-287
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    • 2000
  • We analyzed the 3-dimensional discharge characteristic in plasma display panel(PDP) cell using the 3-dimensional emission distribution of 828nm light measured by scanned point detecting method(SPDM). The emitted light distributions on the ITO electrode show the stronger light intensity near to the electrode gap than outside. Also, 828nm light is widely detected outside of the bus electrode. We consider that measurement using new SPDM is effective to analyze the discharge physics and propose the new panel structures.

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단일 위치에서의 측정을 이용한 가속도 종파 분리 방법의 개발 (Development of longitudinal acceleration wave decomposition method with single point measurement)

  • 정병보;박영진;박윤식
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2006년도 춘계학술대회논문집
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    • pp.629-633
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    • 2006
  • We investigated a new longitudinal acceleration wave decomposition method in time domain. The proposed method separates up- and down-stream waves with an axial strain and axial acceleration measured at a single point on the transmission path. The advantages such as low computation load and easy implementation would be possible by developing time domain under the following assumptions; low frequency range, uniform cross sectional area and elastic wave propagation. We confirmed the feasibility and performance of the method through experiment using Split Hopkinson Pressure Bar (SHPB). The method can be effective in several applications, including active vibration control with wave view point, where real time wave decomposition is necessary.

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원형 웨이브릿 변환을 이용한 배전계통의 고장점 추출 (Mother Wavelet Transform using Distribution Utility of Fault Point Extraction)

  • 박인덕;이승환;최광진;김시경
    • 전기학회논문지
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    • 제58권10호
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    • pp.1855-1860
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    • 2009
  • This paper caused a distribution utility to generation of analysis fault several cases on the ground of substation in a energy meter three phase current, voltage data measurement to fault type and characteristics. Mother wavelet transformation of suitable to method algorithm from the distribution utility to generation of fault in image impedance etc several parameter for utility characteristics effective to probatory fault point extraction.