• 제목/요약/키워드: measurement point

검색결과 3,247건 처리시간 0.029초

안전한 토석류 관리를 위한 계측기 선정에 관한 연구 (Study of Determination in Measurement System for Safely Managing Debris-Flow)

  • 민대홍;윤형구
    • 한국안전학회지
    • /
    • 제32권3호
    • /
    • pp.41-47
    • /
    • 2017
  • Recent studies have shown that there are various systems which can be used to monitor hazardous area in a debris flow location, but lack of methodological research on the exact location where each instrument should be installed has hindered the success of this systems. The objective of this study is to suggest the measurement system for monitoring debris-flow and propose the effective method to determine location of measurement system. Previously studied, from 1991 to 2015, were referred and the applied ratio of every instrument was investigated. The measurement information was divided into 8 categories including rainfall, debris-flow velocity, displacement, fluid pore pressure, ground vibration, image processing, impact force and peak flow depth. The result of this study revealed that the most applied instruments to be rain gauge and geophone for measuring average rainfall and ground vibration respectively. The Analytic Hierarchical Process (AHP) method was selected to determine installation location of instrument and the weighting factors were estimated through fine content, soil thickness, porosity, shear strength, elastic modulus, hydraulic conductivity and saturation. The soil thickness shows highest weights and the fine content relatively demonstrates lowest weights. The score of each position can be calculated through the weighting factors and the lowest score position can be judged as the weak point. The weak point denotes the easily affecting area and thus, the point is suitable for installing the measurement system. This study suggests a better method for safely managing the debris-flow through a precise location for installing measurement system.

토노메트리 측정 관점에서의 부침맥 고찰 (Review on Floating Pulse and Sinking Pulse in the View Point of Tonometric Measurement)

  • 이전;이유정;유현희;이혜정;김종열
    • 한국한의학연구원논문집
    • /
    • 제14권2호
    • /
    • pp.113-119
    • /
    • 2008
  • In pulse diagnosis, floating pulse and sinking pulse are frequently used for diagnosis about where disease is located and how much severe they are. However, in what mechanism floating pulse and sinking pulse arise is not known well. There are two point of views on substantial of floating pulse and sinking pulse. The first one is the floating and sinking degrees is the expression on the depth of pulsation. And, the second one is floating and sinking pulse is based on the response of pulsation to the indent pressure on radial artery. In this paper, we discussed these two opinions in the view point of tonometric measurement. The process for diagnosis on floating pulse and sinking pulse is similar to the tonometric measurement for non invasive blood pressure or intraocular pressure. We modelled the degrees of depth of pulsation with different indent pressures for initial pulsation feeling and different slopes of indent pressure lines. From this modelling, we can confirm the effect of pulsation depth on P-H curve, that is, in the model where lower pulsation is assumed, the shift of optimal indent pressure to the right was observed. The response of pulse pressure to the indent pressure was tried to be modelled with the degrees of mean blood pressure. Consequently, we tried to model the phenomenon of floating and sinking pulse for the first. And, from this modelling, we can get abundant understanding on how floating and sinking pulse can be caused. In the further study, we want to prove the suitability of this tonometric measurement based modelling with various studies including ultrasound measurement for the depth of pulsation in different EMI subjects.

  • PDF

A Study on Breast Type Classification & Discrimination Using Manual Measurement- Focusing on Korean Women in Their 20s -

  • Sohn, Boo-Hyun
    • 한국컴퓨터정보학회논문지
    • /
    • 제25권5호
    • /
    • pp.137-146
    • /
    • 2020
  • 20대 미혼 여성 182명의 직접 계측치를 이용한 유방유형 분류에 유방전체 형상 요인, 유방상부내측형상 요인, 유방볼륨 요인, 유방하부외측형상 요인 등 4가지 요인이 추출되었다. 군집분석을 통해 '상부발달 유방', '밋밋한 유방', '하부 발달 유방', '돌출한 유방' 등 4유형의 유방유형으로 분류하였다. 유방유형은 목앞점~젖꼭지점길이, 목옆점~젖꼭지점길이, 유방안쪽점 사이간격, 젖꼭지 간격, 유방아래직경, 유방내측깊이, 유방바깥쪽길이, 유방아래길이, 젖가슴가쪽점~젖가슴위쪽점길이, 젖가슴 밑 윤곽선길이 등 10개 항목으로 판별 가능하다.

측정된 점데이터 기반 삼각형망 곡면 메쉬 모델의 국부적 자동 수정 (Automatic Local Update of Triangular Mesh Models Based on Measurement Point Clouds)

  • 우혁제;이종대;이관행
    • 한국CDE학회논문집
    • /
    • 제11권5호
    • /
    • pp.335-343
    • /
    • 2006
  • Design changes for an original surface model are frequently required in a manufacturing area: for example, when the physical parts are modified or when the parts are partially manufactured from analogous shapes. In this case, an efficient 3D model updating method by locally adding scan data for the modified area is highly desirable. For this purpose, this paper presents a new procedure to update an initial model that is composed of combinatorial triangular facets based on a set of locally added point data. The initial surface model is first created from the initial point set by Tight Cocone, which is a water-tight surface reconstructor; and then the point cloud data for the updates is locally added onto the initial model maintaining the same coordinate system. In order to update the initial model, the special region on the initial surface that needs to be updated is recognized through the detection of the overlapping area between the initial model and the boundary of the newly added point cloud. After that, the initial surface model is eventually updated to the final output by replacing the recognized region with the newly added point cloud. The proposed method has been implemented and tested with several examples. This algorithm will be practically useful to modify the surface model with physical part changes and free-form surface design.

Exploration of temperature effect on videogrammetric technique for displacement monitoring

  • Zhou, Hua-Fei;Lu, Lin-Jun;Li, Zhao-Yi;Ni, Yi-Qing
    • Smart Structures and Systems
    • /
    • 제25권2호
    • /
    • pp.135-153
    • /
    • 2020
  • There has been a sustained interest towards the non-contact structural displacement measurement by means of videogrammetric technique. On the way forward, one of the major concerns is the spurious image drift induced by temperature variation. This study therefore carries out an investigation into the temperature effect of videogrammetric technique, focusing on the exploration of the mechanism behind the temperature effect and the elimination of the temperature-caused measurement error. 2D videogrammetric measurement tests under monotonic or cyclic temperature variation are first performed. Features of measurement error and the casual relationship between temperature variation and measurement error are then studied. The variation of the temperature of digital camera is identified as the main cause of measurement error. An excellent linear relationship between them is revealed. After that, camera parameters are extracted from the mapping between world coordinates and pixels coordinates of the calibration targets. The coordinates of principle point and focal lengths show variations well correlated with temperature variation. The measurement error is thought to be an outcome mainly attributed to the variation of the coordinates of principle point. An approach for eliminating temperature-caused measurement error is finally proposed. Correlation models between camera parameters and temperature are formulated. Thereby, camera parameters under different temperature conditions can be predicted and the camera projective matrix can be updated accordingly. By reconstructing the world coordinates with the updated camera projective matrix, the temperature-caused measurement error is eliminated. A satisfactory performance has been achieved by the proposed approach in eliminating the temperature-caused measurement error.

A Study on Displacement Measurement Hardware of Retaining Walls based on Laser Sensor for Small and Medium-sized Urban Construction Sites

  • Kim, Jun-Sang;Kim, Jung-Yeol;Kim, Young-Suk
    • 국제학술발표논문집
    • /
    • The 9th International Conference on Construction Engineering and Project Management
    • /
    • pp.1250-1251
    • /
    • 2022
  • Measuring management is an important part of preventing the collapse of retaining walls in advance by evaluating their stability with a variety of measuring instruments. The current work of measuring management requires considerable human and material resources since measurement companies need to install measuring instruments at various places on the retaining wall and visit the construction site to collect measurement data and evaluate the stability of the retaining wall. It was investigated that the applicability of the current work of measuring management is poor at small and medium-sized urban construction sites(excavation depth<10m) where measuring management is not essential. Therefore, the purpose of this study is to develop a laser sensor-based hardware to support the wall displacement measurements and their control software applicable to small and medium-sized urban construction sites. The 2D lidar sensor, which is more economical than a 3D laser scanner, is applied as element technology. Additionally, the hardware is mounted on the corner strut of the retaining wall, and it collects point cloud data of the retaining wall by rotating the 2D lidar sensor 360° through a servo motor. Point cloud data collected from the hardware can be transmitted through Wi-Fi to a displacement analysis device (notebook). The hardware control software is designed to control the 2D lidar sensor and servo motor in the displacement analysis device by remote access. The process of analyzing the displacement of a retaining wall using the developed hardware and software is as follows: the construction site manager uses the displacement analysis device to 1)collect the initial point cloud data, and after a certain period 2)comparative point cloud data is collected, and 3)the distance between the initial point and comparison point cloud data is calculated in order. As a result of performing an indoor experiment, the analyses show that a displacement of approximately 15 mm can be identified. In the future, the integrated system of the hardware designed here, and the displacement analysis software to be developed can be applied to small and medium-sized urban construction sites through several field experiments. Therefore, effective management of the displacement of the retaining wall is possible in comparison with the current measuring management work in terms of ease of installation, dismantlement, displacement measurement, and economic feasibility.

  • PDF

원형치수 계산도구에 의한 바디스 원형 평가 연구 (A Study on Basic Pattern Evaluations Utilizing a Bodice Sloper Size Measurement Tool)

  • 홍지운;권숙희
    • Human Ecology Research
    • /
    • 제54권4호
    • /
    • pp.427-440
    • /
    • 2016
  • This study uses comparison tests of bodice basic patterns to research improvements in wearing evaluation methods based on differences in bodice basic patterns and body size. As study methods, we calculated body sizes for six types by selecting four types of bodice basic pattern and utilized bodice basic pattern size measurement tools. The study result are as follows. First, as the result of analyzing bodice basic patterns per each part and body size difference by bodice basic pattern size measurement tool, shoulder angle cover rate was J&K type 57.57%~68.41%, N type 53.13%~65.57%, L type 51.87%~63.73%, and H type 59.03%~68.20%. In the item of neck base circumference, it was J&K type 6.4~-16 mm, N type 10.7~-31.9 mm, L type -5.2~-13.4 mm, and H type -6.2~-15.4 mm. In the item of armscye circumference, it was J&K type -18.9~-59.4 mm, N type -15.2~-51.3 mm, L type -38.9~-52.7 mm, and H type -17~-42.2 mm. In the item of biacromion length, it was J&K type 23.2~-4.7 mm, N type 18.4~-10.4 mm, and H type 3.5~-5.7 mm. In the item of interscye back, it was J&K type and N type 17.6~-13.6 mm, L type 11.9~-13.6 mm, and H type 3.2~-11.8 mm. The item of interscye front was found in the sequences of study type and L type. Second, the Kruskal-Wallis test result (according to bodice basic pattern) indicated meaningful differences in items of shoulder angle cover rate, neck point to breast point, bust point-bust point, biacromion length and armscye circumference and H type had an overall higher rank.

디지털 영상을 이용한 터널 3차원 변위 계측 (Measurement of Tunnel 3-D Displacement using Digital Photogrammetry)

  • 김광염;김창용;이승도;서용석;이정인
    • 지질공학
    • /
    • 제17권4호
    • /
    • pp.567-576
    • /
    • 2007
  • 디지털 영상을 통한 터널 내공의 3차원 절대변위 계측의 현장 적용성 검토를 위해 OO터널 현장에 계획된 내공변위 계측단면 상에 위치한 광파 타겟의 변위를 측정하고자 하였다. 디지털 영상 계측을 위한 3차원 입체모델 생성을 위해 측정위치마다 3개의 측선까지의 타겟만 고려하였다. 하나의 입체모델의 생성을 위해서 각 위치에서 3장 이상의 디지털 영상을 획득하여 입체모델을 구성하였으며, 마지막 2개 측선에서의 6개 타겟(천단, 좌우 측벽)을 계속 중첩시켜가며 다음 입체 모델을 구성하여 6개 이상의 정합점이 두 입체모델에서 공유될 수 있도록 하였다. 광파 계측과 디지털 영상계측을 통한 터널 시공 중 암반의 3차원 절대변위 계측 방법을 비교하기 위해 10회에 걸쳐 디지털 영상 계측과 광파 계측을 동일한 구간에 동시에 적용하였다. 각 방법을 사용한 계측에 소요되는 시간과 계측결과를 비교하였다.

비정규 측정오차의 경우 측정시스템 변동과 PTR 추정 (Estimations of Measurement System Variability and PTR under Non-normal Measurement Error)

  • 장무성;김상부
    • 품질경영학회지
    • /
    • 제35권1호
    • /
    • pp.10-19
    • /
    • 2007
  • ANOVA is widely, used for measurement system analysis. It assumes that the measurement error is normally distributed, which nay not be seen in some industrial cases. In this study the estimates of the measurement system variability and PTR (precision-to-tolerance ratio) are obtained by using weighted standard deviation for the case where the measurement error is non-normally distributed. The Standard Bootstrap method is used foy estimating confidence intervals of measurement system variability and PTR. The point and confidence interval estimates for the cases with normally distributed measurement error are compared to those with non-normally distributed measurement errors through computer simulation.

레이저 간섭계를 이용한 드릴링 머신의 틸트 측정 (Tilt Measurement of Drilling Machine Using the Laser Interferometer)

  • 이승수;손영지;김순경;전언찬
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 1996년도 추계학술대회 논문집
    • /
    • pp.479-484
    • /
    • 1996
  • This paper describes a method of measuring tilt motion. This method measures the tilt motion of drilling machines using a laser interferometer, a simple sliding linear bearing, measurement of the probe and the LSC(least square center) method. The next order of business is discussing the procedure of measurement. First, The measured position is considered to be the point of contact between the drill shank and the probe. The revolution of the drill axis delivers the point of contact to the probe. Second, because the laser interferometer is attached on the sliding linear bearing, any movement of probe influences laser reflector. Thus, the laser program displays the moving factor of laser reflector. Namely, this is tilt factor. Third. the points of measurement are a full circle which has 8 points (each are 45$^{\circ}$), After it is finished measuring the 8 points, let the spindle of the drilling machine move down about 5 cm. Repeating this procedure three times, we can get tilt motion's values which are calculated by LSC method. Many error factors affect the accurate measurement of tilt motion. However in this paper we ignore some error factors because they are less significant than tilt motion.

  • PDF