• Title/Summary/Keyword: Projection area

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A Study on the Quantitative Analysis of View by the Projection Method in the Residential Buildings (주거용 건물에서의 투영법에 의한 조망의 정량적 분석에 관한 연구)

  • 김용이;김광우
    • Journal of the Korean housing association
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    • v.14 no.5
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    • pp.37-46
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    • 2003
  • The quantitative analysis of view tells how surroundings and sky are showed, and requires understanding of visual perception and three dimensional information of buildings. The visual perception and the existing projection methods for view analysis are examined. The results of this study are as follows: The visual perception on the size is determined by the visual angle, which can be described as a solid angle. The analysis of view by planar projection can be narrow-sighted according to the size of the window and the location of the viewpoint, which will cause the obstacles in the normal direction of the window interfere the view. For the analysis of view by fisheye projection, the area around the focus point is calculated wider than other areas, and so the view ratio depends on the position of the focus point. When analyzing sky view by dividing the sky vault into the differential area, the distortion by projection can be minimized.

A Study on the Comparision Between Map Projection Methods of TM and Polyhedric (TM 및 다면체 투영법(投影法)의 비교고찰(比較考察))

  • Park, Wei-Keun
    • Journal of Korean Society for Geospatial Information Science
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    • v.6 no.2 s.12
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    • pp.119-132
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    • 1998
  • Much information on the terrain and the space has been depicted to maps of various form according to the map scale and the application. In Korea the base map system was made by only one projection method(Transvers Mercator projection). This is the reason to study this paper, because I think singular map projection method can't satisfy the various map scales and application. In this paper Meridian Are Length, Parallel Are Length of ellipsoid and the area of ellipsoidal surface-the length, the width and area of the map scale 1/5,000, 1/25,000, 1/5,000, 1/1,000, will be calculated and transformed to the plane length and area by Transvers Mercartor projection and Polyhedrical projection. The projection distortion which came into existence on this occasion was compared and analyzed by this Paper. And Properties on TM and Polyhedrical projection were understood. Lastly this paper intended to present suitable map projections according to the map scales and the purpose of use.

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Metal Area Segmentation in X-ray CT Images Using the RNA (Relevant Neighbor Ar ea) Principle

  • Kim, Youngshin;Kwon, Hyukjoon;Kim, Joongkyu;Yi, Juneho
    • Journal of Korea Multimedia Society
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    • v.15 no.12
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    • pp.1442-1448
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    • 2012
  • The problem of Metal Area Segmentation (MAS) in X-ray CT images is a very hard task because of metal artifacts. This research features a practical yet effective method for MAS in X-ray CT images that exploits both projection image and reconstructed image spaces. We employ the Relevant Neighbor Area (RNA) idea [1] originally developed for projection image inpainting in order to create a novel feature in the projection image space that distinctively represents metal and near-metal pixels with opposite signs. In the reconstructed result of the feature image, application of a simple thresholding technique provides accurate segmentation of metal areas due to nice separation of near-metal areas from metal areas in its histogram.

Development of a Pig's Weight Estimating System Using Computer Vision (컴퓨터 시각을 이용한 돼지 무게 예측시스템의 개발)

  • 엄천일;정종훈
    • Journal of Biosystems Engineering
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    • v.29 no.3
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    • pp.275-280
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    • 2004
  • The main objective of this study was to develop and evaluate a model for estimating pigs weight using computer vision for improving the management in Korean swine farms in Korea. This research was carried out in two steps: 1) to find a model that relates the projection area with the weight of a pig; 2) to implement the model in a computer vision system mainly consisted of a monochrome CCD camera, a frame grabber and a computer system for estimating the weight of pigs in a non-contact, real-time manner. The model was developed under an important assumption there were no observable genetic differences among the pigs. The main results were: 1) The relationship between the projection area and the weight of pigs was W = 0.0569 ${\times}$ A - 32.585($R^2$ = 0.953), where W is the weight in kg; A is the projection area of a pig in $\textrm{cm}^2$; 2) The model could estimate the weight of pigs with an error less than 3.5%.

Method and Apparatus for Digital Auto Convergence of Projection Video Display

  • Tai, Wen-Chih;Mo, Chi-Neng;Juan, Chang-Jung;Tsai, Ming-Jong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1171-1174
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    • 2005
  • This thesis provides a new digital convergence method and apparatus which uses area photo sensor and new analog to digital algorithmic to identify the correct digital pattern position factor of the projection system. This method and apparatus can be applied to the convergence correction in a TV receiver with a display that comprises a display screen with photo sensors positioned adjacent to screen edges. It also can be applied to the manufacture process detection of the projection system to adjust the associative convergence parameter. In this paper, demonstrate how this convergence detecting algorithmic was implemented with four area photo sensors of special designed pattern to the rear projection CRT TV.

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Realtime Implementation Method for Perspective Distortion Correction (원근 왜곡 보정의 실시간 구현 방법)

  • Lee, Dong-Seok;Kim, Nam-Gyu;Kwon, Soon-Kak
    • Journal of Korea Multimedia Society
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    • v.20 no.4
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    • pp.606-613
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    • 2017
  • When the planar area is captured by the depth camera, the shape of the plane in the captured image has perspective projection distortion according to the position of the camera. We can correct the distorted image by the depth information in the plane in the captured area. Previous depth information based perspective distortion correction methods fail to satisfy the real-time property due to a large amount of computation. In this paper, we propose the method of applying the conversion table selectively by measuring the motion of the plane and performing the correction process by parallel processing for correcting perspective projection distortion. By appling the proposed method, the system for correcting perspective projection distortion correct the distorted image, whose resolution is 640x480, as 22.52ms per frame, so the proposed system satisfies the real-time property.

A Study on Population Change and Projection in Korea Mountainous Area (산촌지역 인구변동의 특성 분석과 장래 추계)

  • Min, Kyung-Taek;Kim, Myeong-Eun
    • Journal of Korean Society of Forest Science
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    • v.103 no.4
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    • pp.670-678
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    • 2014
  • This paper analyzes the characteristics of population change and makes the population projection in the mountainous area of Korea. Mountainous areas are defined as local towns (eup or myeon) with forest area more than 70 percent of land area, population density less than 111 people per square kilometer, and plowland area less than 21 percent of land area. The population in mountainous areas has decreased dramatically, while the ageing index has increased over the past two decades. To make the population projection, the cohort-change ratios method is applied. The results revealed that a multitude of young people aged 10 to 39 moved to cities to find education and job chance and some people aged 40 and over moved to mountainous areas as the trends of urban-to-rural migration. This continuing trend will culminate in 680 thousand people in population and 1,035 of ageing index in 2030, which will lead to the unequal land development and inefficient forest management. Thus, policy makers need to develop stimulus plans to revitalize and stabilize the economy of mountainous areas.

MEASURING CROWN PROJECTION AREA AND TREE HEIGHT USINGLIDAR

  • Kwak Doo-Ahn;Lee Woo-Kyun;Son Min-Ho
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.515-518
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    • 2005
  • LiDAR(Light Detection and Ranging) with digital aerial photograph can be used to measure tree growth factors like total height, height of clear-length, dbh(diameter at breast height) and crown projection area. Delineating crown is an important process for identifying and numbering individual trees. Crown delineation can be done by watershed method to segment basin according to elevation values of DSMmax produced by LiDAR. Digital aerial photograph can be used to validate the crown projection area using LiDAR. And tree height can be acquired by image processing using window filter$(3cell\times3cell\;or\;5cell\times5cell)$ that compares grid elevation values of individual crown segmented by watershed.

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Evaluation of Fatigue Strength in Ductile Cast Iron by Maximum and Mean Size of Graphite (최대 및 평균 구상흑연크기에 의한 구상흑연주철재의 피로강도의 평가)

  • Yoon, Myung-Jin
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.1
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    • pp.82-87
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    • 2012
  • For different ferrite-pearlite matrix structure, contain more than 90% spheroidal ratio of graphite, GCD 45-3, GCD 50, GCD 60 series and 70%, 80%, 90% spheroidal ratio of graphite, GCD 40, GCD 45-1, GCD 45-2 series, this paper has carried out rotary bending fatigue test, estimated maximum and mean size of spheroidal graphite, investigated correlation. It was concluded as follows. (1) Fatigue limit in $10^7$cycles and numbers of spheroidal graphite per 1$mm^2$ was linear relation. (2) projection area of graphite can be used to predict fatigue limit of Ductile Cast Iron. The Statistical distribution of extreme values of projection area of defects may be used as a guideline for the control of inclusion size in the steelmaking processes.

Accuracy Improvement of Output in Projection Stereolithography by Optimizing Projection Resolution (전사방식 광조형 시스템의 해상도 최적화를 통한 출력물의 정밀도 향상)

  • Kim, Yeong-Heum;Kim, Kyu-Eon;Lee, Chibum
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.24 no.6
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    • pp.710-717
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    • 2015
  • Projection stereolithography is an additive manufacturing method that uses beam projection to cure the photo-reactive resin used. The light source of a cross-section layer-form illuminates photo-curable resin for building a three-dimensional (3D) model. This method has high accuracy and a fast molding speed because the processing unit is a face instead of a dot. This study describes a Scalable Projection Stereolithography 3D Printing System for improving the accuracy of the stereolithography. In a conventional projection 3D printer, when printing a small sized model, many pixels are not used in the projection or curing. The proposed system solves this problem through an optical adjustment, and keeps using the original image as possible as filling the whole projection area. The experimental verification shows that the proposed system can maintain the highest level of precision regardless of the output size.