• Title/Summary/Keyword: measurement point

Search Result 3,223, Processing Time 0.033 seconds

Comparison of Size between direct-measurement and 3D body scanning (중국 성인여성의 직접계측과 3D Body scanning 치수 비교 연구)

  • Cha, Su-Joung
    • Journal of Fashion Business
    • /
    • v.16 no.1
    • /
    • pp.150-159
    • /
    • 2012
  • This study intend to analyze differences between 3D body scanning sizes and direct measurement sizes of same subjects. The subjects of study are female students of university in China. 3D data analyze as a 3D Body Measurement Soft System. The conclusion found is as below: In case of circumferences, error between direct-measurement size and 3D body scanning size is from 4.9mm to 62.2mm. The neck circumference size of directmeasurement is bigger than 3D body scanning size. The height error range is from 0.6mm to 51mm. Height of underbust, waist and hip are that direct-measurement sizes are higher than 3D body scanning sizes. Gap of width is from 3.8mm to 21.9mm. The gap range is too narrow relatively to others. Only direct-measurement size of neck width is wider than 3D body scanning size. Error range of length is from 0.3mm to 41.8mm. 3D body scanning sizes of lateral neck to waistline, upperarm length, arm length, neck shoulder point to breast point, shoulder center point to breast point, lateral shoulder to breast point are longer than direct-measurement sizes. They have a negative margin of error. I intend to set up same measurement point between direct-measurement and 3D body scanning but they have some errors because direct-measurement point is applied by a person. 3D body scanning measurement point is settled by automatic system. A measurement point of direct-measurement and 3D body scanning isn't unite. So we need to make a standard of setting up measurement points.

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

  • Mahmood, Talat;Ibrahim, Mounir;Aqeel, Muhammad
    • Progress in Medical Physics
    • /
    • v.28 no.3
    • /
    • 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.

A Study on Structural Intensity Measurement of 2-dimensional Structure (2차원 구조물의 진동 인텐시티 계측에 대한 연구)

  • 이덕영;박성태
    • Journal of KSNVE
    • /
    • v.7 no.3
    • /
    • pp.477-488
    • /
    • 1997
  • In order to control vibration in structures, it is desirable to be able to identify dominant paths of vibration transmission from sources through the structure to some points of interest. Structural intensity vector(power flow per width of cross section) using cross spectra is able to measure the vibration power flow at a point in a structure. This paper describes the structural intensity measurement of 2-dimensional structure. Structural intensity of 2-dimensional structure can be obtained from eight point cross spectral measurement per axis, or two point measurement per axis on the assumption of far field. Approximate formulation of the relation between bending waves in structures and structural intensity makes it possible to separate the wave components by which one can get a state of the vibration field. Experimental results are obtained on an infinite plate at the near and far field in flexural vibration. The measurement error of two point measurement is rather bigger than eight point measurement on account of the assumption that Poisson's ratio is 1. The structural intensity vectors on the plate are checked the ability to identify the path of vibration power flow in random excitation and 200Hz sine excitation, the result of two point measurememt is almost the same as the result of eight point measurement in 200Hz sine excitation.

  • PDF

Point Cloud Measurement Using Improved Variance Focus Measure Operator

  • Yeni Li;Liang Hou;Yun Chen;Shaoqi Huang
    • Current Optics and Photonics
    • /
    • v.8 no.2
    • /
    • pp.170-182
    • /
    • 2024
  • The dimensional accuracy and consistency of a dual oil circuit centrifugal fuel nozzle are important for fuel distribution and combustion efficiency in an engine combustion chamber. A point cloud measurement method was proposed to solve the geometric accuracy detection problem for the fuel nozzle. An improved variance focus measure operator was used to extract the depth point cloud. Compared with other traditional sharpness evaluation functions, the improved operator can generate the best evaluation curve, and has the least noise and the shortest calculation time. The experimental results of point cloud slicing measurement show that the best window size is 24 × 24 pixels. In the height measurement experiment of the standard sample block, the relative error is 2.32%, and in the fuel nozzle cone angle measurement experiment, the relative error is 2.46%, which can meet the high precision requirements of a dual oil circuit centrifugal fuel nozzle.

A Study on the Setting of Breast Measurement Points on 3D Scan Data

  • Sohn, Boo-Hyun;Han, Hyun-Suk
    • Journal of the Korea Society of Computer and Information
    • /
    • v.25 no.5
    • /
    • pp.81-90
    • /
    • 2020
  • In this paper, we propose setting measurement point in the 3D scan data based on the manual measurement data. The optimal 3D body scan postures and measurement points for automatic measurement of breast were set up. The outer breast point may be different depending on the body shape or standing posture as it is on the line connected from the bisecting point of the lateral waist thickness to front armpit point. Therefore, it is necessary to consider the breast-related outer point proposed in this study. And many researches need to reduce the differences between MAM and 3D dimension items associated with the upper breast point. When measuring depth, the difference by pressing in MAM should be taken into account. And the differences in flexion depending on breast type can make a difference in the 3D measurement. So the measurement method in 3D scan should be further studied depending on the types of breast and verified by multiple subjects.

A Study on Structural Intensity Measurement of Semi-infinite Beam (반무한보의 진동 인텐시티 계측에 대한 연구)

  • 이덕영;박성태
    • Journal of KSNVE
    • /
    • v.7 no.1
    • /
    • pp.43-53
    • /
    • 1997
  • This paper investigated the practical use for measuring the structural intensity (power flow per width of cross section) in a uniform semi-infinite beam in flexural vibration. The structural intensity is obtained as a vector at a measurement point, One-dimensional structural intensity can be obtained from 4-point cross spectral measurement, or 2-point measurement on the assumption of far field. The measurement errors due to finite difference approximation and phase mismatch of accelerometers are examined. For precise measurements, it would be better to make the value of k$\delta$(wave number x space between accelerometers) between 0.5 and 1.0. Formulation of the relation between bending waves in structures and structural intensity makes it possible to separate the wave components by which one can get a state of the vibration field. Experimental results are obtained from 2- and 4-point measurement performed at 200mm (near field) and 400mm (far field) apart from excitation point in random excitation. the results are compared with the theoretical values and measured values of input power spectrum in order to verify the accuracy of structural intensity method, 2-point method is suggested as the practical structural intensity method.

  • PDF

Process Design and Case Study for Efficient Function Point Measurement Based on Object Oriented (객체지향 기반 효율적인 기능점수 측정 프로세스 설계 및 사례연구)

  • Kim, Dong-Sun;Yoon, Hee-Byung
    • The KIPS Transactions:PartD
    • /
    • v.15D no.3
    • /
    • pp.375-386
    • /
    • 2008
  • Recently, development paradigm of information system is turning into object oriented and component based, and this methodology is leading the software industry. To acclimatize aptly to this trend, users demand the assessment of software expenses to change with the appropriate model of computing costs of the environment, and some people are actually studying the concept of Object Oriented Function Point and UCP method. Especially, Object Oriented Function Point Measurement Process has good points in overcoming the bound of LOC and the existing the Function Point Measurement Process because Object Oriented Function Point Measurement Process is applicable to the early stage of development project mainly with the used cases, and valid to the life long period as the each stage of software products develops, and always understandable to communicate with users by the UML mark rules. Accordingly, this research is to measure Functional Point at ROFP and AOFP in accordance with the development project of information system by the national defense CBD methodology procedures and UML Interrelation Analysis that are recently and widely used in the developmental environment of object oriented information system. Furthermore, this study suggests the measurement method to obtain Functional Point, and identifies service function and object/class function in the correlation analysis of use case and class based on the products and UML modeling via traditional FPA model and object oriented FPA model. Above all, this study is to demonstrate the improvement of traditional Function Point Measurement Process, IFPUG-CPM and software cost basis, and reveal Function Point Measurement Process, which is appropriate to the development of object oriented information system, and suggest the evaluation results of the compatibility through case studies.

The study on SLA system architecture for IP TV (IP TV를 위한 SLA 시스템 구조에 관한 연구)

  • Kim, Seong-Hwan;Lee, Gil-Haeng
    • Proceedings of the IEEK Conference
    • /
    • 2005.11a
    • /
    • pp.47-52
    • /
    • 2005
  • In this paper we describe SLA metrics and software architecture for newly upcoming IP TV service. Firstly we show the general description for IP TV. This consists of brief description of IP TV, the general figure of configuration and elements of IP TV network and communication protocol stack of IP TV data transmission for deriving communication quality parameter. And we propose SLA metrics depending on quality measurement point. According to the measurement point the measurable SLA metrics are different. The total view of the IP TV SLA measurement and management architecture is shown. When the quality measurement point is the routers that consist of internet node, the IP media NMS is the quality collection system. And when the quality measurement point is the IP TV STB(Set-Top Box), the IP media collector and Quality Collection Server are the quality collection system. And we show the software block diagram of IP TV SLA processing system and the other related network management systems.

  • PDF

The Development and Evaluation of OMM(On the Machine Measuring) System Using Scanning Probe (Scanning Probe를 이용한 OMM(On the Machine Measuring) 시스템 개발 및 평가)

  • Kim, S.H.;Kim, I.H.
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.13 no.10
    • /
    • pp.71-77
    • /
    • 1996
  • This paper describes the development of on the machine measuring(OMM) system which can directlry measure the three dimensional machined dimensilnal accuracy using scanning probe in milling machine. Two algolithms, continuous path(CP) measurement using UC program and CAD data assisted point to point(PTP) measurement, were developed regarding specification of scanning probe. The OMM system was contructed to verify the developed system suing the proposed algorithm, and actually measured three kinds of machined TV shadow mask molds. The developed system was evaluated it's repeatability and compared with the current measurement system of CMM(Coording Measuring Machine) in terms of relative accuracy and time reduction and productivity increase.

  • PDF

Precision Measurement of Silicon Wafer Resistivity Using Single-Configuration Four-Point Probe Method (Single-configuration FPP method에 의한 실리콘 웨이퍼의 비저항 정밀측정)

  • Kang, Jeon-Hong;Yu, Kwang-Min;Koo, Kung-Wan;Han, Sang-Ok
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.60 no.7
    • /
    • pp.1434-1437
    • /
    • 2011
  • Precision measurement of silicon wafer resistivity has been using single-configuration Four-Point Probe(FPP) method. This FPP method have to applying sample size, shape and thickness correction factor for a probe pin spacing to precision measurement of silicon wafer. The deference for resistivity measurement values applied correction factor and not applied correction factor was about 1.0 % deviation. The sample size, shape and thickness correction factor for a probe pin spacing have an effects on precision measurement for resistivity of silicon wafer.