• Title/Summary/Keyword: 형상 분류

Search Result 430, Processing Time 0.028 seconds

Interrelationship between Shape Irregularity and Structural System of Buildings (건물 형상의 비성형성과 구조시스템의 상관관계 분석)

  • Lee, Jae-Cheol;Kim, Hyun-Su
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 2010.04a
    • /
    • pp.251-254
    • /
    • 2010
  • 본 연구에서는 세계 각지의 초고층 건축물 사례 55개를 대상으로 초고층 형상의 비정형성을 대표적 유형에 따라 분류하고 해당 유형에 적용된 구조시스템을 조사함으로써 건축물의 비정형 형상과 이를 구현하기 위해 적용된 구조시스템간의 상관관계를 분석하였다. 대표적인 비정형 형상을 5개 유형으로 분류하고 구조시스템의 적용빈도를 조사한 결과, 적용 사례가 많은 Extrusions와 Tapers 형태에서는 적용된 구조시스템과의 유의미한 상관관계를 파악할 수 있었으며, 적용 사례가 많지 않은 Twisters, Tilted, Free Form 형태에서는 구조시스템의 상대적 적용 경향을 파악할 수 있었다. 본 연구의 결과는 비정형 형상에 적합한 구조시스템 대안의 우선순위를 설정하고 구조시스템 생성을 위해 형상으로부터 추출해내야 할 초기 파라미터를 선정하는데 활용할 수 있을 것으로 기대된다.

  • PDF

An Ultrasonic Pattern Recognition Approach to Welding Defect Classification (용접 결함 분류를 위한 초음파 형상 인식 기법)

  • Song, Sung-Jin
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.15 no.2
    • /
    • pp.395-406
    • /
    • 1995
  • Classification of flaws in weldments from their ultrasonic scattering signals is very important in quantitative nondestructive evaluation. This problem is ideally suited to a modern ultrasonic pattern recognition technique. Here brief discussion on systematic approach to this methodology is presented including ultrasonic feature extraction, feature selection and classification. A stronger emphasis is placed on probabilistic neural networks as efficient classifiers for many practical classification problems. In an example probabilistic neural networks are applied to classify flaws in weldments into 3 classes such as cracks, porosity and slag inclusions. Probabilistic nets are shown to be able to exhibit high performance of other classifiers without any training time overhead. In addition, forward selection scheme for sensitive features is addressed to enhance network performance.

  • PDF

Interactive Shape Analysis of the Hippocampus in a Virtual Environment (가상 환경에서의 해마 모델에 대한 대화식 형상 분석☆)

  • Kim, Jeong-Sik;Choi, Soo-Mi
    • Journal of Internet Computing and Services
    • /
    • v.10 no.5
    • /
    • pp.165-181
    • /
    • 2009
  • This paper presents an effective representation scheme for the shape analysis of the hippocampal structure and a stereoscopic-haptic environment to enhance sense of realism. The parametric model and the 3D skeleton represent various types of hippocampal shapes and they are stored in the Octree data structure. So they can be used for the interactive shape analysis. And the 3D skeleton-based pose normalization allows us to align a position and an orientation of the 3D hippocampal models constructed from multimodal medical imaging data. We also have trained Support Vector Machine (SVM) for classifying between the normal controls and epileptic patients. Results suggest that the presented representation scheme provides various level of shape representation and the SVM can be a useful classifier in analyzing the shape differences between two groups. A stereoscopic-haptic virtual environment combining an auto-stereoscopic display with a force-feedback (or haptic) device takes an advantage of 3D applications for medicine because it improves space and depth perception.

  • PDF

Computer Aided Design of the Fore and After Body of Fishing Vessel by Using B-Spline (B-Spline을 이용한 어선의 선수미부 초기 선형 설계)

  • Kim, Dong-Jun;Hong, Bong-Gi
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.27 no.1
    • /
    • pp.75-82
    • /
    • 1991
  • The present paper describes a preliminary design method by using the computer graphics for creation of the fore and after body profiles of fishing vessel. It is well known that the Form Parameter design method has some merits at an early stage of design, and the B-spline curve generation technique has some prior properties in representing hull form with the computer graphic. The B-spline curve generation technique combined with the form parameter design method is employed to generate the profiles of fishing vessel. For fore body the stem profiles with bulbous bulb or without one are considered. And for after body the stern profiles of cruiser type and the transom type are generated with stern bulb or with shoe piece. Several examples will shown.

  • PDF

Determination of Threshold Value for Extracting Shape Information of the Objects (물체의 형상정보추출에 있어서의 임계값의 선정)

  • 조동욱;이성석;김기영
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.17 no.2
    • /
    • pp.187-195
    • /
    • 1992
  • This paper propose on the determination of threshold values for extracting shape information of the objects. First, surface curvatures such as mean curvature and gaussian curvature is calculated from given range data. And then local surface regions are classified into the one of 8 primitives by using the sign of mean curvature H and gaussian curvature K. Also from the statistical viewpoint. the range of the zero of H and K in the range is obtained through the analysis of the relation between mean curvature and gaussian curvature. Finally, the effectiveness of the proposed mithod in this paper is demonstrated by comparing with a case, where the zero threshold is arbitrarily obtained.

  • PDF

Selecting Representative Views of 3D Objects By Affinity Propagation for Retrieval and Classification (검색과 분류를 위한 친근도 전파 기반 3차원 모델의 특징적 시점 추출 기법)

  • Lee, Soo-Chahn;Park, Sang-Hyun;Yun, Il-Dong;Lee, Sang-Uk
    • Journal of Broadcast Engineering
    • /
    • v.13 no.6
    • /
    • pp.828-837
    • /
    • 2008
  • We propose a method to select representative views of single objects and classes of objects for 3D object retrieval and classification. Our method is based on projected 2D shapes, or views, of the 3D objects, where the representative views are selected by applying affinity propagation to cluster uniformly sampled views. Affinity propagation assigns prototypes to each cluster during the clustering process, thereby providing a natural criterion to select views. We recursively apply affinity propagation to the selected views of objects classified as single classes to obtain representative views of classes of objects. By enabling classification as well as retrieval, effective management of large scale databases for retrieval can be enhanced, since we can avoid exhaustive search over all objects by first classifying the object. We demonstrate the effectiveness of the proposed method for both retrieval and classification by experimental results based on the Princeton benchmark database [16].

Solder Paste Pattern Classification Using the XOR Operation in Vision Inspection Machines (비젼 검사시스템에서 XOR연산을 이용한 납땜형상의 패턴분류)

  • Lee, Chang-Gil;Hwang, Jung-Ho;Kim, Min-Soo
    • Proceedings of the KIEE Conference
    • /
    • 2001.07d
    • /
    • pp.2735-2737
    • /
    • 2001
  • 비젼 검사시스템에서 기판에 존재하는 납 형상의 패턴을 분류함으로써 사전에 불량을 줄일 수 있다. 이러한 경우 대부분의 불량은 부정확한 납의 위치 및 두께로 인해 발생하게 되는데, 이러한 문제를 해결하기 위해 주어진 경계 내에 불분명하게 형성된 납의 형태 및 두께를 정상과 불량으로 분류하기 위해 무게중심점에 기초한 정합과 XOR연산을 이용한 비젼 검사시스템을 제안하였다. 제안한 비젼 검사시스템을 인쇄회로기판상의 납땜형상 패턴에 적용하여 제안한 방법의 성능을 검증하였다.

  • PDF

Development of Adaptive Signal Pattern Recognition Program and Application to Classification of Defects in Weld Zone by AE Method (적응형 신호 형상 인식 프로그램 개발과 AE법에 의한 용접부 결함 분류에 관한 적용 연구)

  • Lee, K.Y.;Lim, J.M.;Kim, J.S.
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.16 no.1
    • /
    • pp.34-45
    • /
    • 1996
  • The signal pattern recognition program which can perform signal acquisition and processing, the extraction and selection of features, the classifier design and the evaluation, is developed and applied to the classification of artificial defects in the weld zone of Austenitic STS304. The neural network classifier is compared with the linear discriminant function classifier and the empirical Bayesian classifier. The signal through a broadband sensor is compared with that through a resonance type sensor. In recognition rate, the neural network classifier is best, and the signal through a broadband sensor is better.

  • PDF

Classification of Type in North Korean Literature and Art. - focused on concepts and standards of classification - (북한 문학예술의 유형분류 연구 - 분류개념과 기준을 중심으로 -)

  • Kim, Jung-su
    • (The) Research of the performance art and culture
    • /
    • no.19
    • /
    • pp.123-160
    • /
    • 2009
  • North Korea classify literature and art according to some concepts and standards. First, as concepts, North Korea classify Literature and Art in a species and a type. But in 1996, North Korea added third concept, a kind of Genre, Galae. This shows us that North Korea attempts to subdivide Literature and Art in classification. But there are not fixed contents in each type. So we can say that North Korea emphasis on principles of classification and at the same time they have a flexible attitude. Second, as standards, North Korea in 1987 used manner depicted, medium employed, capacity, a literary style, figured plot, quality and in 1992 used manner depicted, medium employed, object depicted, a mission, a function and in 1996 used manner depicted, medium employed, object depicted, a form of plot and in 2007 used manner depicted, medium employed, a scale and a capacity of work, a quality of materials and contents, emotional color of works, and so forth. So we can say that North Korea regard classification as an important thing as a basic work for developed Literature and art in future. And to South Korea, classification means that it could suggest a way for creative work for Literature and Art.

Characteristics for Sludge Removal Nozzle in Steam Generator (증기 발생기 슬러지 제거용 노즐 특성 연구)

  • Lee Sam-Goo
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.8 no.3
    • /
    • pp.37-43
    • /
    • 2004
  • Water-jet trajectory visualization and velocity deficits from a high pressurized steam-generator nozzles were experimentally observed. In order to find an optimal nozzle configuration. several parameters affecting plugging and erosion onto the steam generator tube were quantitatively analyzed. For the experiments, a high-pressurized pump (pressure in use: 200 kg/$\textrm{cm}^2$, 15 HP, 11 kW, output flow Q : 301/min) was utilized. Visualization, velocity distribution, and spray growth rate with different nozzle configurations have been mainly focused using a 2-D PDPA system. The results indicated that trajectories along the centerline regardless of their configurations has its potential core region. However, the phenomena from the peripheral part need to be meticulously considered. Accordingly, it is evident that quantitative velocity deficits at the outer region are outstanding due to the aerodynamical drag and entrainment.