• 제목/요약/키워드: Detection intensity

검색결과 963건 처리시간 0.026초

Tsunami-induced Change Detection Using SAR Intensity and Texture Information Based on the Generalized Gaussian Mixture Model

  • Jung, Min-young;Kim, Yong-il
    • 한국측량학회지
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    • 제34권2호
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    • pp.195-206
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    • 2016
  • The remote sensing technique using SAR data have many advantages when applied to the disaster site due to its wide coverage and all-weather acquisition availability. Although a single-pol (polarimetric) SAR image cannot represent the land surface better than a quad-pol SAR image can, single-pol SAR data are worth using for disaster-induced change detection. In this paper, an automatic change detection method based on a mixture of GGDs (generalized Gaussian distribution) is proposed, and usability of the textural features and intensity is evaluated by using the proposed method. Three ALOS/PALSAR images were used in the experiments, and the study site was Norita City, which was affected by the 2011 Tohoku earthquake. The experiment results showed that the proposed automatic change detection method is practical for disaster sites where the large areas change. The intensity information is useful for detecting disaster-induced changes with a 68.3% g-mean, but the texture information is not. The autocorrelation and correlation show the interesting implication that they tend not to extract agricultural areas in the change detection map. Therefore, the final tsunami-induced change map is produced by the combination of three maps: one is derived from the intensity information and used as an initial map, and the others are derived from the textural information and used as auxiliary data.

밝기순위 특징을 이용한 적외선 정지영상 내 물체검출기법 (Object Detection in a Still FLIR Image using Intensity Ranking Feature)

  • 박재희;최학훈;김성대
    • 대한전자공학회논문지SP
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    • 제42권2호
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    • pp.37-48
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    • 2005
  • 본 논문에서는 적외선 영상에서 밝기변화를 예측하기 어려운 일정한 크기의 관심 물체를 검출하기 위하여, 밝기순위 특징과 이론 이용한 물체식별기법을 제안한다. 제안하는 밝기순위 특징은 밝기값의 분포가 균일하도록 영상을 정규화하여 나타낸 것으로, 적외선 영상과 같이 검출대상 물체의 밝기분포를 쉽게 예측하기 어려운 경우에 적합한 특징이다. 제안하는 식별기법은 주어진 후보영역이 검출대상 물체의 학습영상들에 대해 밝기순위가 부합하는 정도를 수치화하여 각각의 후보영역을 물체와 비물체로 식별한다 제안하는 기법을 통하여 별도의 후보영역 선정과정 없이도 일정한 크기의 관심 물체에 대해 화소단위의 검출결과를 획득할 수 있다. 실험에서는 적외선 자동차 영상을 이용하여 밝기순위특징이 적외선 영상 내 물체식별에 적합함을 보이고, 잡음 및 물체의 크기변화, 기울어짐이 존재하는 상황에서의 검출결과를 보인다.

Dual Detection-Guided Newborn Target Intensity Based on Probability Hypothesis Density for Multiple Target Tracking

  • Gao, Li;Ma, Yongjie
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제10권10호
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    • pp.5095-5111
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    • 2016
  • The Probability Hypothesis Density (PHD) filter is a suboptimal approximation and tractable alternative to the multi-target Bayesian filter based on random finite sets. However, the PHD filter fails to track newborn targets when the target birth intensity is unknown prior to tracking. In this paper, a dual detection-guided newborn target intensity PHD algorithm is developed to solve the problem, where two schemes, namely, a newborn target intensity estimation scheme and improved measurement-driven scheme, are proposed. First, the newborn target intensity estimation scheme, consisting of the Dirichlet distribution with the negative exponent parameter and target velocity feature, is used to recursively estimate the target birth intensity. Then, an improved measurement-driven scheme is introduced to reduce the errors of the estimated number of targets and computational load. Simulation results demonstrate that the proposed algorithm can achieve good performance in terms of target states, target number and computational load when the newborn target intensity is not predefined in multi-target tracking systems.

Closely Spaced Target Detection using Intensity Sorting-based Context Awareness

  • Kim, Sungho;Won, Jin-Ju
    • Journal of Electrical Engineering and Technology
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    • 제11권6호
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    • pp.1839-1845
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    • 2016
  • Detecting remote targets is important to active protection system (APS) or infrared search and track (IRST) applications. In normal situation, the well-known constant false alarm rate (CFAR) detector works properly. However, decoys in APS or closely spaced targets in IRST degrade the detection capability by increasing background noise level in the CFAR detector. This paper presents a context aware CFAR detector by the intensity sorting and selection of background region to reduce the effect of neighboring targets that lead to incorrect estimation of background statistics. The existence of neighboring targets can be recognized by intensity sorting where neighboring targets usually show highest ranks. The proposed background statistics (mean, standard deviation) estimation method from median local pixels can be aware of the background context and reduce the effects of the neighboring targets, which increase the signal-to-clutter ratio. The experimental results on the synthetic APS sequence, real adjacent target sequence, and remote pedestrian sequence validated that the proposed method produced an enhanced detection rate with the same false alarm rate compared with the hysteresis-CFAR (H-CFAR) detection.

명도와 채도 기반의 점등영역 검출 및 모델 검증에 의한 교통신호등 판별 (Detection of a Light Region Based on Intensity and Saturation and Traffic Light Discrimination by Model Verification)

  • 김민기
    • 한국멀티미디어학회논문지
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    • 제20권11호
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    • pp.1729-1740
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    • 2017
  • This paper describes a vision-based method that effectively recognize a traffic light. The method consists of two steps of traffic light detection and discrimination. Many related studies have used color information to detect traffic light, but color information is not robust to the varying illumination environment. This paper proposes a new method of traffic light detection based on intensity and saturation. When a traffic light is turned on, the light region usually shows values with high saturation and high intensity. However, when the light region is oversaturated, the region shows values of low saturation and high intensity. So this study proposes a method to be able to detect a traffic light under these conditions. After detecting a traffic light, it estimates the size of the body region including the traffic light and extracts the body region. The body region is compared with five models which represent specific traffic signals, then the region is discriminated as one of the five models or rejected as none of them. Experimental results show the performance of traffic light detection reporting the precision of 97.2%, the recall of 95.8%, and correct recognition rate of 94.3%. These results shows that the proposed method is effective.

형광 공초점 주사 현미경의 측정 강도 향상을 위한 반사 광학계의 제안 및 설계 (Proposal and design of reflecting optical system to improve detection intensity in fluorescence confocal scanning microscopy)

  • 강동균;서정우;권대갑
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 춘계학술대회 논문집
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    • pp.187-190
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    • 2002
  • Confocal microscopy is very popular technology in bio-medical inspection due to its ability to reject background signals and to measure very thin slide of thick specimens, which is called optical sectioning. But intensity of detected signal in fluorescence type confocal microscopy is so small that only 0.2% of emitted fluorescence light can be detected in the best case. In this paper, we proposed the reflecting optical system to improve the detection intensity and designed the optical system by optimal design method. At the end of the paper, we analyzed the characteristics of the proposed reflecting optical system.

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플라즈마 식각공정에서의 EPD(End Point Detection) 제어기에 관한 연구 (A study on EPD(End Point Detection) controller on plasma teaching process)

  • 최순혁;차상엽;이종민;우광방
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.415-418
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    • 1996
  • Etching Process, one of the most important process in semiconductor fabrication, has input control part of which components are pressure, gas flow, RF power and etc., and plasma gas which is complex and not exactly understood is used to etch wafer in etching chamber. So this process has not real-time feedback controller based on input-output relation, then it uses EPD(End Point Detection) signal to determine when to start or when to stop etching. Various type EPD controller control etching process using EPD signal obtained from optical intensity of etching chamber. In development EPD controller we concentrate on compensation of this signal intensity and setting the relative signal magnitude at first of etching. We compensate signal intensity using neural network learning method and set the relative signal magnitude using fuzzy inference method. Potential of this method which improves EPD system capability is proved by experiences.

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조명 변화에 강인한 얼굴 검출을 위한 좌우대칭 평균화 기법 (A Bilateral Symmetry Average Method for Robust Face Detection against Illumination Variation)

  • 조치영;김수환
    • 게임&엔터테인먼트 논문지
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    • 제2권2호
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    • pp.45-50
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    • 2006
  • 형판 정합 기반의 얼굴 검출 시스템에서 획득된 이미지에 대한 명암 정규화 및 영상 보정을 위해 히스토그램 평활화나 로그 변환 등을 사용한다. 이 방법은 조명 변화에 의해 발생한 이미지의 부분 명암 왜곡에는 효과적이지 못하다는 것이 알려져 있다. 본 논문에서는 부분적 명암 왜곡에 매우 효과적인 영상 보정을 수행하는 좌우대칭 평균화 기법을 제시한다. 실험 결과 이 기법은 기존의 방식보다 매우 효율적인 검출 성능을 보일 뿐만 아니라 얼굴 후보의 개수도 현저하게 감소하는 것으로 나타났다.

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Thermoluminescence 측정에 의한 감자와 마늘의 방사선 조사유무 확인 (Detection of Irradiated Potato and Garlic by Thermoluminescence Measurement)

  • 정형욱;권중호
    • 한국식품과학회지
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    • 제30권2호
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    • pp.283-287
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    • 1998
  • 발아억제 선량범위인 0.15 kGy와 0.30 kGy의 감마선과 전자선이 조사된 감자와 마늘을 대상으로 thermoluminescence (TL) 측정에 의해 방사선 조사유무를 확인하였다. 감자와 마늘로부터mineral을 추출하여 TL 측정을 함으로써 방사선 조사선량과 TL intensity 간의 높은 상관관계를 확인하였다. 방사선 조사되지 않은 시료들은 특이한 TL glowcurve를 나타내지 않았으나 방사선 조사된 시료들은 $200{\sim}260^{\circ}C$부근에서 명확한 TL glowcurve를 나타내었다. 시료의 TL intensity는 조사선량에 따라 증가하였으나 같은 조사선량에서도 방사선 조사선원에 따라 시료의 TL intensity는 일정하지 않았다. 그러나 이상의 결과에서 볼 때 발아억제를 위한 감자와 마늘의 방사선 조사는 TL glowcurve의 측정으로써 조사유무의 확인이 가능하였다.

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