• Title/Summary/Keyword: Detection Probability

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A Study on Detection Probability Reduction of LPI Radar's Platform (저피탐(LPI) 레이더 탑재 플랫폼의 피탐 확률 감소에 관한 연구)

  • Park, Tae-Yong;Kim, Wan-Ju
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.5
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    • pp.1243-1248
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    • 2014
  • In General, LPI radar's detection probability by ES equipments is lower than that of conventional pulsed radar because of very low transmitting power and high antenna gain etc. LPI radar is a kind of RF stealth technique such as RCS reduction design. Therefore the ultimate goal of LPI radar is detection probability reduction by opponent. If one of the two, RCS value or LPI radar performance is not sufficient, own platform will be found first by opponent. In this paper, some considerations are suggested for detection probability reduction.

다중 방책 연구

  • Jo Deok-Un;Lee Sang-Yong
    • Journal of the military operations research society of Korea
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    • v.11 no.2
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    • pp.6-14
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    • 1985
  • The layered multi-barrier defense situation against penetrating enemy threat is analytically modeled towards minimizing the penetration probability. Each layer is characterized by probability of detection and probability of kill given detection. The two capabilities are assumed independent. Detection in a layer, however, affects detection performance in subsequent layers. The following three models were formulated and investigated: (1) 'Model A' permits increase of detection performance in only the next barrier, (2) 'Model B' permits the increase in all subsequent barriers linearly, and (3) 'Model C' expresses the increase in an asymptotic exponential way. The best and the worst barrier combinations are determined through model exercise and model performances are compared through sensitivity analysis for the 'intensification factor.'

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A Comparison of LOS Detection Probability Area for DEM and DSM (DEM 과 DSM 의 가시선 탐지확률 비교)

  • Song, Hyun-Seung;Park, Wang-Yong;Park, Hyun-Chun;Lee, Young-Lim
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.29 no.2
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    • pp.165-173
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    • 2011
  • Generally, A acquisition of the target is affected by the detector performance and whether it is covered with features or not. This paper represented the comparative analysis of the detection probability for DEM and DSM, when we used by the infrared surveillance device. In the first place, we c1assified as the visible area and invisible area for DEM and DSM, and obtained the acquisition probability values using the ACQUIRE mode. We have known that The Detection Probability of the DSM is very lower than the DEM and is rising when elevates the height value of the detection point.

Line Segment Detection Algorithm Using Improved PPHT (개선된 PPHT를 이용한 선분 인식 알고리즘)

  • Lee, Chanho;Moon, Ji-hyun;Nguyen, Duy Phuong
    • Journal of IKEEE
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    • v.20 no.1
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    • pp.82-88
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    • 2016
  • The detection rate of Progressive Probability Hough Transform(PPHT) is decreased when a lot of noise components exist due to an unclear or complex original image although it is quite a good algorithm that detects line segments accurately. In order to solve the problem, we propose an improved line detecting algorithm which is robust to noise components and recovers slightly damaged edges. The proposed algorithm is based on PPHT and traces a line segments by pixel and checks of it is straight. It increases the detection rate by reducing the effect of noise components and by recovering edge patterns within a limited pixel size. The proposed algorithm is applied to a lane detection method and the false positive detection rate is decreased by 30% and the line detection rate is increased by 15%.

A Methodology for Partitioning a Search Area to Allocate Multiple Platforms (구역분할 알고리즘을 이용한 다수 탐색플랫폼의 구역할당 방법)

  • An, Woosun;Cho, Younchol;Lee, Chansun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.21 no.2
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    • pp.225-234
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    • 2018
  • In this paper, we consider a problem of partitioning a search area into smaller rectangular regions, so that multiple platforms can conduct search operations independently without requiring unnecessary coordination among themselves. The search area consists of cells where each cell has some prior information regarding the probability of target existence. The detection probability in particular cell is evaluated by multiplying the observation probability of the platform and the target existence probability in that cell. The total detection probability within the search area is defined as the cumulative detection probability for each cell. However, since this search area partitioning problem is NP-Hard, we decompose the problem into three sequential phases to solve this computationally intractable problem. Additionally, we discuss a special case of this problem, which can provide an optimal analytic solution. We also examine the performance of the proposed approach by comparing our results with the optimal analytic solution.

Successive MAP Detection with Soft Interference Cancellation for Iterative Receivers in Hierarchical M-ary QAM Systems (M-레벨 QAM 계층 변조 시스템에서 연 간섭 제거를 이용한 연속 MAP 판정 기법)

  • Kim, Jong-Kyung;Seo, Jong-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.3C
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    • pp.304-310
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    • 2009
  • This paper proposes a successive MAP (maximum a posteriori probability) detection scheme with SoIC(soft interference cancellation) to reduce the receiver complexity of hierarchical M-ary QAM system. For the successive MAP detection, modulation symbols generated from the other data streams are treated as Gaussian noise or eliminated as the soft interference according to their priorities. The log-likelihood ratio of the a posteriori probability (LAPRP) of each bit is calculated by the MAP detector with an adjusted noise variance in order to take the elimination and Gaussian assumption effect into account. By separating the detection process into the successive steps, the detection complexity is reduced to increase linearly with the number of bits per hierarchical M-ary QAM symbol. Simulation results show that the proposed detection provides a small performance degradation as compared to the optimal MAP detection.

The Surface Sidelobe Clutter and the False Alarm Probability of Target Detection for the HPRF Waveform of the Microwave Seeker (마이크로파 탐색기의 HPRF 파형에 대한 지표면 부엽클러터와 표적탐지 오류 확률)

  • Kim, Tae-Hyung;Yi, Jae-Woong;Byun, Young-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.4C
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    • pp.476-483
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    • 2009
  • Tracking and detecting targets by the microwave seeker is affected by the clutter reflecting from the earth's surface. In order to detect retreating targets in look-down scenario, which appear in the sidelobe clutter (SLC) region, in the microwave seeker of high pulse repetition frequency (HPRF) mode, it is necessary to understand statistical characteristics of the surface SLC. Statistical analysis of SLC has been conducted for several kinds of the surface using data obtained by the captive flight test of the microwave seeker in the HPRF mode. The probability density function (PDF) fitting is conducted for several kinds and conditions of the surface. PDFs and PDF parameters, which best describe statistical distribution of the SLC power, are estimated. By using the estimated PDFs and PDF parameters, analyses for setting the target-detection thresholds, which give a desired level of target-detection false alarm probability, are made. These analysis materials for statistical characteristics of SLC power and the target-detection threshold can be used in various fields, such as development of a target-detection method, the constant false alarm rate processing.

Symbol Timing & Carrier Frequency Offset Estimation Method for UWB MB-OFDM System (UWB MB-OFDM 시스템을 위한 심볼 타이밍 및 반송파 주파수 오프셋 추정 기법)

  • Kim Jung-Ju;Wang Yu-Peng;Chang Kyung-Hi
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.3A
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    • pp.232-239
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    • 2006
  • In this paper, we analyze the preamble model for Wireless PAN(WPAN) in proposed Ultra WideBand(UWB) Multi-Band OFDM(MB-OFDM) system of IEEE 802.15.3a standard. Besides, we propose effective Carrier Frequency Offset and Symbol Timing Offset Estimation algorithm which offers enhanced performance, and analyze its performance using Detection Probability, False Alarm Probability, Missing Probability, Mean Acquisition Time and MSE(Mean Square Error) through simulation in AWGN and UWB channel environments.

Evaluation of the Probability of Detection Surface for ODSCC in Steam Generator Tubes Using Multivariate Logistic Regression (다변량 로지스틱 회귀분석을 이용한 증기발생기 전열관 ODSCC의 POD곡면 분석)

  • Lee, Jae-Bong;Park, Jai-Hak;Kim, Hong-Deok;Chung, Han-Sub
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.250-255
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    • 2007
  • Steam generator tubes play an important role in safety because they constitute one of the primary barriers between the radioactive and non-radioactive sides of the nuclear power plant. For this reason, the integrity of the tubes is essential in minimizing the leakage possibility of radioactive water. The integrity of the tubes is evaluated based on NDE (non-destructive evaluation) inspection results. Especially ECT (eddy current test) method is usually used for detecting the flaws in steam generator tubes. However, detection capacity of the NDE is not perfect and all of the "real flaws" which actually existing in steam generator tunes is not known by NDE results. Therefore reliability of NDE system is one of the essential parts in assessing the integrity of steam generators. In this study POD (probability of detection) of ECT system for ODSCC in steam generator tubes is evaluated using multivariate logistic regression. The cracked tube specimens are made using the withdrawn steam generator tubes. Therefore the cracks are not artificial but real. Using the multivariate logistic regression method, continuous POD surfaces are evaluated from hit (detection) and miss (no detection) binary data obtained from destructive and non-destructive evaluation of the cracked tubes. Length and depth of cracks are considered in multivariate logistic regression and their effects on detection capacity are evaluated.

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Modeling and Design of a Distributed Detection System Based on Active Sonar Sensor Networks (능동 소나망 분산탐지 체계의 모델링 및 설계)

  • Choi, Won-Yong;Kim, Song-Geun;Hong, Sun-Mog
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.1
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    • pp.123-131
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    • 2011
  • In this paper, modeling and design of a distributed detection system are considered for an active sonar sensor network. The sensor network has a parallel configuration and it consists of a fusion center and a set of receiver nodes. A system with two receiver nodes is considered to investigate a theoretical aspect of design. To be specific, AND rule and OR rule are considered as the fusion rules of the sensor network. For the fusion rules, it is shown that a threshold rule of each sensor node has uniformly most powerful properties. Optimum threshold for each sensor is obtained that maximizes the probability of detection given probability of false alarm. Numerical experiments were also performed to investigate the detection characteristics of a distributed detection system with multiple sensor nodes. The experimental results show how signal strength, false alarm probability, and the distance between nodes in a sensor field affect the system detection performances.