• 한국의학물리학회지:의학물리
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• 제28권3호
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• pp.111-121
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• 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.

• 패션비즈니스
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• 제16권1호
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• pp.150-159
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• 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.

• 소음진동
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• 제7권3호
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• pp.477-488
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• 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.

• 정보처리학회논문지D
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• 제15D권3호
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• pp.375-386
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• 2008

최근 정보시스템 개발 패러다임이 객체지향 및 컴포넌트 기반으로 변해가고 있으며 이러한 방법론이 소프트웨어 산업계를 주도하고 있다. 소프트웨어 비용측정 분야도 이러한 변화에 적응하기 위해서 OO 환경에 적합한 비용 측정 모델로의 전환이 요구되고 있으며 실제 UCP 기법 등 객체지향 개념의 기능점수 연구가 진행되고 있다. 특히 객체지향 기능점수 측정 기법은 사용사례 중심으로 개발 프로젝트 초기에 적용 가능하고, 개발 진행 단계별 소프트웨어 산출물에 따라 생명주기 전체에 걸쳐서 적용 가능하고, UML 표기법에 의한 사용자와 의사소통으로 이해가 항상 가능하기 때문에 LOC 및 기존 기능점수 측정 기법의 한계를 극복하는 장점이 있다. 따라서 본 논문은 최근 객체지향 정보시스템 개발 환경에서 널리 사용되고 있는 UML 표기법 및 국방 CBD 방법론 절차에 의한 정보시스템 개발 프로젝트 진행에 따라 초기단계 시점(ROFP)과 분석단계 시점(AOFP)에서 기능점수를 측정하며, 전통적인 FPA 모델과 객체지향 FPA 모델을 통해 UML 모델링과 산출물을 기반으로 한 유스케이스와 클래스의 상관도 분석에서 서비스 기능과 객체/클래스 기능을 식별하고 기능점수를 구하는 측정기법을 제안한다. 무엇보다 전통적인 기능점수 측정 기법인 IFPUG-CPM 및 소프트웨어 대가기준의 기능점수 측정기법을 개선하여 객체지향 정보시스템 개발에 적합한 기능점수 측정 프로세스를 제시하고 사례연구를 통한 적합성 평가 결과를 제시한다.

• Current Optics and Photonics
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• 제8권2호
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• pp.170-182
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• 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.

• 소음진동
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• 제7권1호
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• pp.43-53
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• 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.

• 한국컴퓨터정보학회논문지
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• 제25권5호
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• pp.81-90
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• 2020

직접 측정방법을 기반으로 3차원 스캔 데이터에서 유방의 자동측정을 위한 유방과 관련된 측정점 설정과 이상적인 3차원 스캔 자세를 제안하였다. 특히 직접 측정법에서의 유방 바깥쪽점은 체형과 자세에 따라 변동되기 쉬우므로 3차원 측정법에서는 유방에서 찾는 새로운 방법을 제안하였다. 유방의 윤곽선이 뚜렷하지 않은 유방 위쪽의 유방 위쪽점은 겨드랑접힘점을 기준으로 설정되는데 직접측정법에서의 유방 위쪽점이 3차원 스캔데이터에서 측정된 유방위쪽점보다 높게 설정됨을 알 수 있었다. 그러므로 직접 측정치와 3차원 측정치 간의 오차를 줄이기 위해서는 유방 위쪽점 설정에 관여되는 겨드랑앞접힘점 위치가 명확해야 할 것이다. 유방과 관련된 깊이 항목에서는 유방 바깥쪽점을 제외한 모든 깊이에서 직접 측정치가 높게 나타났는데 이는 피부 눌림에 의한 것으로 판단된다. 또 유방의 굴곡이 심한 유방아래길이와 유방아래 접힘선길이, 유방 안쪽점사이 간격은 굴곡에 의해 3차원 측정치가 직접 측정치보다 높게 나타나 유방에 대한 3차원 측정법이 일반화되기 위해서는 다양한 유방유형에 따른 측정치의 변화를 연구할 필요가 있다.

• 한국안전학회지
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• 제22권3호
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• pp.88-97
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• 2007

A point based speed enforcement system(SES) has been widely used in roadways to reduce the operating speeds and potential traffic accidents. Recently, the needs for introudcing new SES using point-to-point speed measurement was presented, however, no practical guidelines or justification of the system was available. This study investigated the effectiveness of the current SES and introduction of the new SES through user interview survey method. Survey results showed that 33% of respondents were unsatisfactory to the current way of SES operation, which was 11% higher than satisfactory respondents, and about 70% of the respondents supported the introduction of point-to-point based SES operation. A majority of respondents preferred the straight roadway segment, bridge and tunnel, and curved roadway segment for a start application site with the segment length of 1-5 km long. Using these survey results, an introduction scheme was discussed in terms of legal bases, installation criteria, and operational guidelines.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.521-526
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• 2004

In order to evaluate the effect of blasting vibration in buildings and it's resident located around blasting construction field in urban area, blasting vibration characteristics were measured the vibration level, vibration velocity. The 250g and 750g of charged powder were used at the apartment and at the ground, respectively. In the measurement of the ground, Z(perpendicularity) axis was the highest value in vibration level, but vertical axis was the highest value at 25m point and longitudinal axis was the highest value at 50m point in vibration velocity. The amount of measurement was high value when measuring point is higher than blasting source, while that of measurement was low value when measuring point is lower than blasting source. In the measurement of the apartment, 2 axis was the highest value in vibration level, but in vibration velocity transverse axis was the highest value at ground, was vertical axis at 1st floor, was longitudinal axis at 3rd floor and was vertical and longitudinal axis at 5th floor. The vibration level and the vibration velocity of 50m point showed higher correlation value than 25m point at the ground, but those of 25m point showed higher correlation value than 50m point at the apartment.

• 한국소음진동공학회논문집
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• 제14권7호
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• pp.632-638
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• 2004

In order to evaluate the effect of blasting vibration in buildings and it's resident located around blasting construction field in urban area, blasting vibration characteristics were measured by the vibration level, vibration velocity. The 250g and 750g of charged powder were used at the apartment and at the ground, respectively. In the measurement of the ground, 2 (perpendicularity) axis was the highest value in vibration level, but vertical direction was the highest value at 25 m point and longitudinal direction was the highest value at 50 m point in vibration velocity. The amount of measurement was high value when measuring point is higher than blasting source, while that of measurement was low value when measuring point is lower than blasting source. In the measurement of the apartment, Z axis was the highest value in vibration level, but in vibration velocity transverse direction was the highest value at ground, was vertical direction at 1st floor, was longitudinal direction at 3rd floor and was vertical and longitudinal direction at 5th floor. The vibration level and the vibration velocity of 50 m point showed higher correlation value than 25 m point at the ground, but those of 25 m point showed higher correlation value than 50 m point at the apartment.