• 제목/요약/키워드: Time resolution

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4차원 영상기법 Time Resolved Imaging of Contrast Kinetics MRA의 유용성 (Four Dimension(4D) Time Resolved Imaging of Contrast Kinetics(TRICKS) MR Angiography)

  • 임청환;배성진
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2009년도 춘계 종합학술대회 논문집
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    • pp.1105-1110
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    • 2009
  • Time Resolved Imaging of Contrast Kinetics 기법을 이용한 4차원 자기공명혈관조영술(TRICKS -MRA)영상과 기존 TOF-MRA영상을 비교하여 임상적 유용성에 대해 알아보고자 하였다. 총 17명 중 뇌 혈관 질환이 의심되는 11명과 뇌 종양을 의심하는 6명을 대상으로 TOF-MRA와 TRICKS -MRA을 시행한 후 17대상자 중 11명에서 DSA를 추가적으로 시행하였다. TOF-MRA는 공간해상력보다 시간해상력이 부족하였고, TRICKS-MRA에서는 TOF-MRA보다 공간분해능은 부족한 점이 많지만 영상판독에 큰 영향은 없었고 모든 대상자에서 동맥과 정맥의 구별이 가능하여 시간분해능이 우수 한 것을 나타났다. 또한 종양과 혈관과의 관계성 평가에서 TOF-MRA보다 좋은 것으로 나타났다. TRICKS-MRA방법은 시간대별로 동맥, 모세혈관, 정맥기를 신속하면서 쉽게 4차원적으로 영상화가 가능하여 앞으로 임상에서 이용도가 더욱 증가 할 것으로 사료된다.

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GPU를 이용한 다양한 해상도의 비디오기반 실시간 화재감지 방법 구현 및 성능평가 (Implementation and Performance Evaluation of a Video-Equipped Real-Time Fire Detection Method at Different Resolutions using a GPU)

  • 손동구;김철홍;김종면
    • 한국컴퓨터정보학회논문지
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    • 제20권1호
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    • pp.1-10
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    • 2015
  • 본 논문에서는 기존에 많이 사용되는 복잡한 4단계 화재 감지 알고리즘의 성능을 향상시키기 위해 그래픽스 처리 장치 (GPU)를 이용한 효율적인 병렬 구현 방법을 제안하였고 성능을 분석하였다. 또한 현재 많이 사용되고 있는 7가지 서로 다른 해상도 (QVGA, VGA, SVGA, XGA, SXGA+, UXGA, QXGA)의 비디오를 입력으로 하여 성능을 분석하였다. 더불어 각 해상도별 GPU 기반 실행시간과 고성능 CPU에서의 실행시간을 비교 분석하였다. 각 해상도의 5가지 화재 및 비 화재 비디오를 이용하여 모의 실험한 결과, GPU는 CPU보다 실행시간에서 우수한 성능을 보이는 동시에 FULL HD급의 높은 해상도인 UXGA 영상에서도 프레임 당 25.11ms의 실행시간이 소요되어 초당 30 프레임의 실시간 처리가 가능함을 보였다.

고분해능의 주파수 추정 알고리즘 개발 (High Resolution Frequency Estimation of Real Sinusoids)

  • 서인용
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 추계학술대회 논문집 전기물성,응용부문
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    • pp.279-282
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    • 2003
  • In this paper, we propose a new high resolution frequency estimator for real sinusoids by using short time data and the AWLS/MFT (Adaptive Weighted Least Squares/ Modulation Function Technique) algorithm. Monte-Carlo simulations verify better performances of the proposed frequency estimator and demonstrate that the proposed AWLS sinusoidal estimator is a high resolution estimator.

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초음파 영상장치에서 측방향 해상도 향상에 관한 연구 (A Study on the Improvement a Lateral Resolution of the Ultrasound Imaging System)

  • 이후정;이행세
    • 대한의용생체공학회:의공학회지
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    • 제9권1호
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    • pp.87-92
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    • 1988
  • In this paper, a new focusing method, to be called the pipelined sampled delay focusing (PSDF), is implemented. This method improves the lateral resolution in ultrasound imaging system. In PSDF, the analog belay lines are no longer necessary because sampling sum process can replace the conventional delay sum process. Also, the method offers continuous dynamic focusing on the resolution pixel basis, and eliminates the constraint that the maximum delay time is less than the sampling interval. Second order sampling is adopted in order to extend the sampling interval.

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웨이브릿 변환을 이용한 마이크로스트립 선로에서의 전파 특성 연구 (A Study on the Propagation Characteristics along the Microstrip Lines using Wavelet Transforms)

  • 이재웅;송용원;김건욱;박한규
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1999년도 하계종합학술대회 논문집
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    • pp.223-226
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    • 1999
  • We study the propagation property of the transient signals along the microstrip using the wavelet transform. Wavelet transform can offer the time-frequency windows. It makes the resolution of time high in high frequency range and the resolution of frequency high in low frequency range. So It is useful to analyze the signals which have both low and high frequency components.

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UAV Conflict Detection and Resolution Based on Geometric Approach

  • Park, Jung-Woo;Oh, Hyon-Dong;Tahk, Min-Jea
    • International Journal of Aeronautical and Space Sciences
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    • 제10권1호
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    • pp.37-45
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    • 2009
  • A method of conflict detection and resolution is described by using simple geometric approach. Two VAVs are dealt with and considered as point masses with constant velocity. This paper discusses en route aircraft which are assumed to be linked by real time data bases like ADS-B. With this data base, all DAVs share the information each other. Calculating PCA (Point of Closest Approach), we can evaluate the worst conflict condition between two VAVs. This paper proposes one resolution maneuvering logic, which can be called 'Vector Sharing Resolution'. In case of conflict, using miss distance vector in PCA, we can decide the directions for two VAVs to share the conflict region. With these directions, VAVs are going to maneuver cooperatively. First of all, this paper describes some '2-D' conflict scenarios and then extends to '3-D' conflict scenarios.

A STUDY ON THE DETERMINATION OF THE INSTANTANEOUS FIELD OF VIEW FOR I-M HIGH RESOLUTION SATELLITE IMAGE

  • Seo Doo-Chun;Park Su-Young;Lee Dong-Han;Lee Sun-Gu;Song Jeong Heon;Lim Hyo-Suk
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.649-652
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    • 2005
  • In this paper we present a detail approach of the determination of IFOV (Instantaneous Field of View) of high-resolution (l m) panchromatic satellite image over test site. IFOV is the representative measurements as the determination of the spatial resolution in remote sensed imaging system. It can be defined as some area on the ground with the particular altitude when the satellite acquires the image at any given time. Especially, spatial resolution of passive sensors primarily depends on their IFOV. The determination of IFOV goes through simple steps of procedure as followings: Firstly, the GSD (Ground Sample Distance) should be computed at each point on the geometrically corrected image. Then, The GSD is converted into the IFOV. So we are going to explain our test procedures and results.

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치과 구내 X-선 촬영기의 사용연한에 따른 해상능에 관한 연구 (A STUDY OF THE RESOLUTION OF DENTAL INTRAORAL X-RAY MACHINES)

  • 김선주;정현대
    • 치과방사선
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    • 제20권2호
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    • pp.289-297
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    • 1990
  • The purpose of this study was to assess the resolution and focal spot size of dental X-ray machines. Fifty dental X-ray machines were selected for measuring resolution and focal spot size. These machines were used in general dental clinics. The time of installation of the X-ray machine varies from 1 year to 10 years. The resolution of these machines was measured with the test pattern. The focal spot size of these machines was measured with the star test pattern. The following results were obtained: 1. The resolution of dental intraoral X-ray machines was not significantly changed in ten years. 2. The focal spot size of dental intraoral X-ray machines was not significantly increased in ten years. The statistical analysis between the mean focal spot size and nominal focal spot size was significant at the 0.05 level about the more than 3 years used machines.

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공동주택 소비자분쟁 경감방안에 관한 연구 (A Study on the Improvement of Consumer Dispute in the Apartment House)

  • 박성용;김석철;오동현
    • 한국중재학회지:중재연구
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    • 제19권3호
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    • pp.199-217
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    • 2009
  • During the urbanization progresses, apartments such as the house of commons, representing our homes are situated in space. However, many consumer problems of our country's apartment house are caused by the government's failure of housing policy and consumer dispute resolution system In this study, apartment house and alleviate consumer disputes relating to in proactive ways to improve the government's housing policy was presented. At the same time, since the revision of Consumer Fundamental Act on collective alternative dispute resolution system has proposed scheme, this occurred after a dispute to resolve the dispute can be more efficient ways.

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무역분쟁(貿易紛爭)의 해결수단(解決手段)으로서 ADR활성화(活性化) 방안(方案)에 관한 연구(硏究) (A Study on the Ways to expand ADR System As a Method of International Trade Dispute Resolution)

  • 신군재
    • 무역상무연구
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    • 제20권
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    • pp.343-365
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    • 2003
  • Dispute plays a key role in maintaining the desirable performance of trade transaction. In an effort to stay competitive in a global marketplace, the Korean companies need to become more aware of alternatives to costly and time-consuming litigation. Korean companies, therefore, should be more concerned with ADR(Alternative Dispute Resolution) system and should utilize ADR to settle their disputes effectively and efficiently. ADR encompasses all process of dispute resolution as a substitute for the traditional litigation. Generally, three kinds of ADR are available in Korea: Negotiation, mediation, and arbitration. This article investigates reasons why ADR isn't used well in Korea and suggests ways how ADR can work best in international trade disputes. To expand ADR system in international trade disputes, it is very important for both the company and the scholar to recognize the concept and usefulness of ADR system. The Korean Commercial Arbitration Board also must help both Korean companies and scholars recognize the mechanism of dispute resolution and utilize ADR system in international trade disputes.

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