• Title/Summary/Keyword: object detection

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A Study on the Optimal Design for the reconstruction Filter in Single Photon Emission Computed Tomography (SPECT) (단일광자방출 전산화 단층촬영상에서 재구성 필터의 최적설계에 관한 연구)

  • 김정희;김광익
    • Journal of Biomedical Engineering Research
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    • v.18 no.2
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    • pp.113-120
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    • 1997
  • This paper presents an optimal design for the SPECT reconstruction filter, based on a physical limit of SPECT lesion detection capability. To increase the performance of the filter on lesion detectability, the filter design was focused on increasing the local SyW ratio of a threshold lesion, that was determined by minimum detectable lesion size (MDU) from SPECT lesion detectabllity contrast-detail curve. The proposed filter showed flexible window characteristics of resolution recovery and noise smoothing for MDLSs in the resolution-limited and photon-limited regions, respectively, compennting for the relative impact of the main limitation factors on threshold detectability. The simulated results showed good adaptability of the proposed filter to the changes in physical parameters of photon counts, object contrast, and detector system resolution.

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A conflict Detection Mechanism for Authorizations of Class Composition Hierarchies in Object-Oriented Database Systems (객체지향 데이터베이스 시스템의 클래스 복합 계층 구주에서의 권한 충돌 탐지 기법)

  • 손태종;김원영;황규영;조완섭
    • Proceedings of the Korean Information Science Society Conference
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    • 1998.10b
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    • pp.45-47
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    • 1998
  • 객체지향 데이터베이스 시스템에서 많이 연구되고 있는 묵시적 권한부여(implicit authorization) 방법은 모든 객체에 대하여 일일이 권한을 부여하는 오버헤드를 줄이기 위한 방법이다. 묵시적 권한부여 방법에서는 기존의 권한과 새로이 추가될 권한간의 충돌(conflict) 여부의 효율적인 검사가 중요하다. 기존의 데이터베이스 단위 계층 구조( database granularity hierarchy)에서의 의도형 권한부여(intention type authorization) 기법은 자신의 자손 노드에 대한 권한을 쉽게 판정할 수는 있지만, 클래스 복합 계층 구조(class composition hierarchy)상에서의 임의의 한 노드 ni에 추가로 권한을 부여할 때 ni의 자손 노드와 복합 참조(composite reference)의 관계를 가지는 노드 nj들에 대한 권한과의 충돌 여부를 탐지하기 위하여 추가로 nj들에 대한 권한을 일일이 탐색해야 하는 어려움이 있었다. 본 논문에서는 클래스 복합 계층 구조에서의 묵시적 권한부여 하에서 발생할 수 있는 권한간의 충돌을 효율적으로 탐지하는 새로운 기법을 확장하여 제안한다. 제안된 복합 계층 의도형 권한부여(intention type authorization for composition hierarchy)기법은 계층 구조에서 복합 참조의 관계를 따라 nj를 일일이 탐색할 필요 없이 노드 ni에서 바로 충돌 여부를 판정할 수 있는 장점을 가진다.

The Binarization of Text Regions in Natural Scene Images, based on Stroke Width Estimation (자연 영상에서 획 너비 추정 기반 텍스트 영역 이진화)

  • Zhang, Chengdong;Kim, Jung Hwan;Lee, Guee Sang
    • Smart Media Journal
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    • v.1 no.4
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    • pp.27-34
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    • 2012
  • In this paper, a novel text binarization is presented that can deal with some complex conditions, such as shadows, non-uniform illumination due to highlight or object projection, and messy backgrounds. To locate the target text region, a focus line is assumed to pass through a text region. Next, connected component analysis and stroke width estimation based on location information of the focus line is used to locate the bounding box of the text region, and each box of connected components. A series of classifications are applied to identify whether each CC(Connected component) is text or non-text. Also, a modified K-means clustering method based on an HCL color space is applied to reduce the color dimension. A text binarization procedure based on location of text component and seed color pixel is then used to generate the final result.

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Moving Object Detection and Tracking in Moving Picture Using Adaptive Thresholding (동영상에서의 적응적인 임계화를 통한 움직임 검출 및 추적)

  • 정미영;최석림
    • Proceedings of the IEEK Conference
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    • 2002.06d
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    • pp.17-20
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    • 2002
  • The methods that track and detect motion field based on image difference of successive images from camera can separate motion field and background effectively, but because of noise and background images getting proper difference images is hard to achieve. In this paper we propose a method that can improve difference image quality significantly. Three step process is used. At the first step, existence of motion field is determined, the second step is finding proper threshold value using 'Contrast Streching' technique which enables us to find proper motion field even in complex images. At last step, remaining noise is removed and motion field is determined.

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Development of Cultural Contents using Auger Reality Based Markerless Tracking

  • Kang, Hanbyeol;Park, DaeWon;Lee, SangHyun
    • International journal of advanced smart convergence
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    • v.5 no.4
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    • pp.57-65
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    • 2016
  • This paper aims to improve the quality of cultural experience by providing a three - dimensional guide service that enables users to experience themselves without additional guides and cultural commentators using the latest mobile IT technology to enhance understanding of cultural heritage. In this paper, we propose a method of constructing cultural contents based on location information such as user / cultural heritage using markerless tracking based augmented reality and GPS. We use marker detection technology and markerless tracking technology to recognize smart augmented reality object accurately and accurate recognition according to the state of cultural heritage, and also use Android's Google map to locate the user. The purpose of this paper is to produce content for introducing cultural heritage using GPS and augmented reality based on Android. It can be used in combination with various objects beyond the limitation of existing augmented reality contents.

Development of People Counting Algorithm using Stereo Camera on NVIDIA Jetson TX2

  • Lee, Gyucheol;Yoo, Jisang;Kwon, Soonchul
    • International journal of advanced smart convergence
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    • v.7 no.3
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    • pp.8-14
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    • 2018
  • In the field of surveillance cameras, it is possible to increase the people detection accuracy by using depth information indicating the distance between the camera and the object. In general, depth information is obtained by calculating the parallax information of the stereo camera. However, this method is difficult to operate in real time in the embedded environment due to the large amount of computation. Jetson TX2, released by NVIDIA in March 2017, is a high-performance embedded board with a GPU that enables parallel processing using the GPU. In this paper, a stereo camera is installed in Jetson TX2 to acquire depth information in real time, and we proposed a people counting method using acquired depth information. Experimental results show that the proposed method had a counting accuracy of 98.6% and operating in real time.

Real-Time Surveillance of People on an Embedded DSP-Platform

  • Qiao, Qifeng;Peng, Yu;Zhang, Dali
    • Journal of Ubiquitous Convergence Technology
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    • v.1 no.1
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    • pp.3-8
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    • 2007
  • This paper presents a set of techniques used in a real-time visual surveillance system. The system is implemented on a low-cost embedded DSP platform that is designed to work with stationary video sources. It consists of detection, a tracking and a classification module. The detector uses a statistical method to establish the background model and extract the foreground pixels. These pixels are grouped into blobs which are classified into single person, people in a group and other objects by the dynamic periodicity analysis. The tracking module uses mean shift algorithm to locate the target position. The system aims to control the human density in the surveilled scene and detect what happens abnormally. The major advantage of this system is the real-time capability and it only requires a video stream without other additional sensors. We evaluate the system in the real application, for example monitoring the subway entrance and the building hall, and the results prove the system's superior performance.

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A Study of Optical Follow-up Pipeline for Gravitational-Wave transients using QUEST data

  • Kim, Yong Bum;Lee, Hyung Mok
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.1
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    • pp.69.2-69.2
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    • 2013
  • The direct detection of gravitational wave has a very important meaning as a basis for verification of the theory of relativity. Several laser interferometer detectors have attempted to detect GW directly (e.g. LIGO, VIRGO), but positional accuracy of GW detector is too wide (about 10~100sq deg) to find which objects emit GW. One of the main sources of GW is gamma-ray burst which can be detected even in electromagnetic wave. Then to verify Gamma-ray burst object as a GW source, we proceed EM follow-up observation with wide field of view. A first program initiating EM follow-ups to possible transients GW events has been developed and exercised by LIGO and VIRGO community in association with several partners. Using QUEST optical data, we tested the method of cross-convolution recommended by EM follow-up community. We will describe the results of that test.

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Effective Moving Object Detection Algorithm for Surveillance System (감시 시스템을 위한 효과적인 움직이는 물체 탐지 알고리즘)

  • Choi, Jeong-Hwan;Baek, Young-Min;Na, Jin-Hee;Choi, Jin-Young
    • Proceedings of the KIEE Conference
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    • 2007.10a
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    • pp.457-458
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    • 2007
  • 우리는 동영상에서 낮은 연산량으로 강인하게 움직이는 물체를 탐지하는 방법을 제안한다. 동영상에서 움직이는 물체를 탐지하기 위한 많은 방법들이 제안되었는데, 각각의 방법은 접근 방법에 따라 탐지 성능과 처리속도에 trade-off가 존재한다. 최근 폭넓게 사용되고 있는 가우시안 혼합모델을 이용한 배경모델생성 법의 경우 탐지성능은 우수하나 연산량이 많고, 차영상(Temporal difference)을 이용한 방법은 연산량은 적으나 노이즈에 민감하게 반응한다. 또한 알고리즘 특성상 탐지된 물체에 Hole과 Ghost가 발생하는 문제가 있다. 우리는 이러한 단점들을 극복하기 위해 이 두 가지 알고리즘을 효율적으로 결합하여 움직이는 물체를 탐지하였다. 실험은 사람, 차, 오토바이와 같이 실외환경에서 흔히 움직이는 물체로 탐지되는 요소들이 다양한 환경에서 실시하였으며, 실험한 결과 배경영역에서 발생하는 노이즈는 효과적으로 제거하면서 움직이는 물체를 탐지하였다.

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Robust RGB image-based gait analysis in various environment (다양한 환경에 강건한 RGB 영상 기반 보행 분석)

  • Ahn, Ji-min;Jeung, Gyeo-wun;Shin, Dong-in;Won, Geon;Park, Jong-beom
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.10a
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    • pp.441-443
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    • 2018
  • This paper deals with the analysis of leg motion using RGB image. We used RGB image as gait analysis element by using BMC(Background Model Challenge) method and by using combining object recognition segmentation algorithm and attitude detection algorithm. It is considered that gait analysis incorporating image can be used as a parameter for classification of gait pattern recognition and abnormal gait.

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