• Title/Summary/Keyword: Shape Data

Search Result 4,975, Processing Time 0.038 seconds

Experimental Study on Scouring Range according to Bridge Pier Shape (교각형상에 따른 국부세굴범위에 대한 실험 연구)

  • Lee, Kap-Yong;Choi, Sung-Nyung;Choi, Sung-Wook;Park, Moo-Jong
    • 한국방재학회:학술대회논문집
    • /
    • 2008.02a
    • /
    • pp.477-480
    • /
    • 2008
  • Hydraulic experiment was executed to identify the souring range of bride pier. The experiment categorized three kind of bridge pier shape, that is composed of circle shape, square shape and the special shape. Measured scouring data was compared with the results by empirical CSU formula which was generally used in practice. As empirical formula could not consider backfill, measured scouring range is by far smaller than results of CSU formula. Therefore in case of design anti-scouring structure, there is the possibility of overestimation in case of using empirical formula.

  • PDF

Feature Template-Based Sweeping Shape Reverse Engineering Algorithm using a 3D Point Cloud

  • Kang, Tae Wook;Kim, Ji Eun;Hong, Chang Hee;Hwa, Cho Gun
    • International conference on construction engineering and project management
    • /
    • 2015.10a
    • /
    • pp.680-681
    • /
    • 2015
  • This study develops an algorithm that automatically performs reverse engineering on three-dimensional (3D) sweeping shapes using a user's pre-defined feature templates and 3D point cloud data (PCD) of sweeping shapes. Existing methods extract 3D sweeping shapes by extracting points on a PCD cross section together with the center point in order to perform curve fitting and connect the center points. However, a drawback of existing methods is the difficulty of creating a 3D sweeping shape in which the user's preferred feature center points and parameters are applied. This study extracts shape features from cross-sectional points extracted automatically from the PCD and compared with pre-defined feature templates for similarities, thereby acquiring the most similar template cross-section. Fitting the most similar template cross-section to sweeping shape modeling makes the reverse engineering process automatic.

  • PDF

Shape offectting using the geometric properties of B -spline curve(1) -A Study on offsetting of B-spline control polygon- (B-스플라인 곡선의 기하특성을 이용한 형상 옵셋(1) -B-스플라인 제어 다각형 옵셋 기법의 연구-)

  • 정재현;김희중
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.20 no.1
    • /
    • pp.44-48
    • /
    • 1996
  • In manufacturing of exact products, the offsetting is required to transfer the design data of shape to manufacturing data. In offsetting the degeneracies are occurred, and these problems are mere difficult in freeform shapr manufacuring. This paper is using the geometric properties of B-spline curves to solve the degeneracy of offsetting and to generating of enhanced offsetting. The offsetting of B-spline control polygon spans generates exact control polygon of original shapes. This method is faster in generating offset curve than the normal offsetting, and the resulted offset curves are exact. The additional property of this method is using to control offset shape as B-spline curves. We believe that this method is as effective solution for modifying of offset curves.

  • PDF

Data Transition Research to Derive Shape Factor in Analyzing Factors -Centering on the body shape of males in twenties- (요인분석시 형태요인을 도출시키기 위한 자료 변환 연구 - 20대 남성 체형을 중심으로 -)

  • 석혜정;김인숙
    • Journal of the Korean Home Economics Association
    • /
    • v.40 no.2
    • /
    • pp.67-86
    • /
    • 2002
  • The purpose of this research is to offer a method to derive the body shapes and pose factors with resets from analyzing factors by using the measurement values of human body. 297 male subjects in their twenties participated in this study. 54 anthropometric and 35 photographic measurements were taken from each subject. Data is the several typical items selected among items and you have to make an index value by using these typical items and convert it. The index has high correlation with each item, is easy to be measured and is to be used after selecting an important item in designing prototype. With results of analyzing reliability level by each item, correlation and items that factor loading is low, the item that the correlation is high is to be removed within the range that maintains the reliability level. Five factors of the front part and seven factors of the profile came to be derived from this kind of process.

Vision Inspection for Large 2D Machining Product using Tolerance Zone (공차영역을 이용한 대형 2차원 가공물의 형상 검사)

  • 이성건;정병묵;조지승
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.19 no.11
    • /
    • pp.112-119
    • /
    • 2002
  • Generally, it is very difficult to inspect geometric shape of large 2D objects after machining. To maintain the accuracy for inspection, a robot vision is used to divide overall shape into several enlarged images, and image processing technique is applied to acquire one minute geometric contour. The inspection is to compare the NC data with the measured contour data by the vision system, and the algorithm is to rotate to minimize the maximum deviation after coinciding two geometric centers. This paper experimentally shows that the proposed algorithm is very useful for inspection of large machined objects.

Upper Back Somatotype Analysis for Development of Hanbok Jeogori Pattern of Female in Late 20s (20대 후반 성인 여성의 한복 저고리 패턴 개발을 위한 상반신 뒷면의 체형 분석)

  • Eom, Ran-I;Lee, Yejin
    • Korean Journal of Human Ecology
    • /
    • v.23 no.5
    • /
    • pp.891-904
    • /
    • 2014
  • The objective of this study is to classify somatotypes of back-surface shape of women in their late 20s by using 3D body scan data(Size Korea 2010) in order to improve fitness of Hanbok Jeogori. The results were as follows: 1. According to the in-depth survey of the experienced expert's interview, most problems related to the fit were caused by the back area of Jeogori. 2. The result of factor analysis indicated that 6 factors were extracted and those factors comprised 82.85% of total variance. 3. According to the cluster analysis, back somatotypes of women in their late 20s were categorized by two types : straight type(54.1%) and bending type(46.9%). The results could be used as the Hanbok Jeogori to improve the fitness of back-surface shape.

Study on body shape changes by Meridian Scraping - focused on upper part of the body - (미용 괄사요법을 이용한 체형 변화 연구 - 상반신을 중심으로 -)

  • Moon, Mi-Jin;Kim, Kyung-Hee
    • Journal of Fashion Business
    • /
    • v.12 no.4
    • /
    • pp.15-27
    • /
    • 2008
  • The purpose of this study is to show data for protocol design which will be able to change body shape using the measured value before and after Meridian Scraping Massage with the Martin-type anthropometer through experiment result and questionnaire. The data analysis was done by paired-sample t-test using SPSS program and today, Meridian Scraping Therapy is being applied by various instruments which use meridian pathway and spots on the body suitable for acupuncture which promote blood circulation by eliminating toxin and maintaining body fluids balance. And they have such merit as easy to buy material and perform operation without side effect only if understanding massage principal.

Noise reduction for mesh smoothing of 3D mesh data

  • Hyeon, Dae-Hwan;WhangBo, Taeg-Keun
    • International Journal of Contents
    • /
    • v.5 no.4
    • /
    • pp.1-6
    • /
    • 2009
  • In this paper, we propose a mesh smoothing method for mesh models with noise. The proposed method enables not only the removal of noise from the vertexes but the preservation and smoothing of shape recognized as edges and comers. The magnitude ratio of 2D area and 3D volume in mesh data is adopted for the smoothing of noise. Comparing with previous smoothing methods, this method does not need many iteration of the smoothing process and could preserve the shape of original model. Experimental results demonstrate improved performance of the proposed approach in 3D mesh smoothing.

Likelihood based inference for the shape parameter of Pareto Distribution

  • Lee, Jae-Un;Lee, Woo-Dong
    • Journal of the Korean Data and Information Science Society
    • /
    • v.19 no.4
    • /
    • pp.1173-1181
    • /
    • 2008
  • In this paper, when the parameter of interest is the shape parameter in Pareto distribution, we develop likelihood based inference for this parameter. Specially, we develop signed log-likelihood ratio statistic and the modified signed log-likelihood ratio statistic for the shape parameter. It is well-known that as sample size grows, the modified signed log-likelihood ratio statistic converges to standard normal distribution faster than the signed log-likelihood ratio statistic. But the computation of the modified signed log-likelihood statistic is hard or even impossible when the sufficient statistics and the ancillary statistics are not clear. In this case, one can consider an approximation to the modified signed log-likelihood statistic. Specially, when the parameter of interest is informationally orthogonal to the nuisance parameters, we propose the approximate modified signed log-likelihood statistic. Through simulation, we investigate the performances of the proposed statistics with the signed log-likelihood statistic.

  • PDF

매뉴얼 프로그램에 의한 비구면 형상 가공에 관한 연구

  • 박준용;권영균;이동주
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
    • /
    • 2002.10a
    • /
    • pp.280-285
    • /
    • 2002
  • Copy machines have been used in the 3 dimensional shape machining like the non-sphere surface. This study is intended to show the possibility of manufacturing of a non-sphere shape without a exclusive CAM(Computer Aided Manufacturing) software in the process of metallic mold. It has been examined under the two types of working conditions. One is a cutting by manual programming and the other is a cutting by a general-purpose CAM software. Two kinds of output data were compared and analyzed, and data by a manual program were discovered more accurate than those of a general-purpose CAM software. In this study, I came to a conclusion it is possible to manufacture a 3 dimensional shape without a exclusive CAM software.

  • PDF