• Title/Summary/Keyword: False target

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Underwater target discrimination using geometry of ACM tracks (음향교란 항적의 기하학적 특성을 이용한 수중 표적 판별)

  • 정영헌;전상운;홍선목
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.3
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    • pp.110-119
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    • 1998
  • In this paper we discuss an algorithm to discriminate a garget under track against multiple acoustic counter-measure (ACM) sources, based on sequential testings of multiple hypotheses. The ACM sources are separated from the target under track and generate, while drifting, measurements with false range and Doppler information. The purpose of the ACM is to mislead the target tracking and to help the true target evade a pursuer. The proposed algorithm uses as a test statistic a function of the innovation sequences from extended Kalman filters to estimate the target dynamics and the drifting positions of the ACM sources. results of numerical experimenats are presented to show a performance profile of the proposed algorithm.

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Adaptive Target Detection Algorithm Using Gray Difference, Similarity and Adjacency (밝기 차, 유사성, 근접성을 이용한 적응적 표적 검출 알고리즘)

  • Lee, Eun-Young;Gu, Eun-Hye;Yoo, Hyun-Jung;Park, Kil-Houm
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38B no.9
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    • pp.736-743
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    • 2013
  • In IRST(infrared search and track) system, the small target detection is very difficult because the IR(infrared) image have various clutter and sensor noise. The noise and clutter similar to the target intensity value produce many false alarms. In this paper. We propose the adaptive detection method which obtains optimal target detection using the image intensity information and the prior information of target. In order to enhance the target, we apply the human visual system. we determine the adaptive threshold value using image intensity and distance measure in target enhancement image. The experimental results indicate that the proposed method can efficiently extract target region in various IR images.

Small Target Detection Using Cross Product Based on Temporal Profile in Infrared Image Sequences (적외선 영상 시퀀스에서 시간적 프로파일 기반의 외적을 사용한 소형 표적 검출)

  • Kim, Byoung-Ik;Bea, Tea-Wuk;Kim, Young-Choon;Ahn, Sang-Ho;Kim, Duk-Gyoo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.1C
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    • pp.8-16
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    • 2010
  • This paper presents a new small target detection method using the cross product of the temporal pixels based on the temporal profile in infrared (IR) image sequences. The temporal characteristics of small targets and the various backgrounds are different. A new algorithm classifies target pixels and the background pixels through the hypothesis testing using the cross product of pixels on the temporal profile and predicts the temporal backgrounds based on the results. The small targets are detected by subtracting the predicted temporal background profile from the original temporal profile. For the performance comparison between the proposed algorithm and the conventional algorithms, the receiver operating characteristics (ROC) curves is computed in experiment. Experimental results show that the proposed algorithm has better discrimination and a lower false alarm rate than the conventional methods.

Deep learning-based target distance and velocity estimation technique for OFDM radars (OFDM 레이다를 위한 딥러닝 기반 표적의 거리 및 속도 추정 기법)

  • Choi, Jae-Woong;Jeong, Eui-Rim
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.1
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    • pp.104-113
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    • 2022
  • In this paper, we propose deep learning-based target distance and velocity estimation technique for OFDM radar systems. In the proposed technique, the 2D periodogram is obtained via 2D fast Fourier transform (FFT) from the reflected signal after removing the modulation effect. The periodogram is the input to the conventional and proposed estimators. The peak of the 2D periodogram represents the target, and the constant false alarm rate (CFAR) algorithm is the most popular conventional technique for the target's distance and speed estimation. In contrast, the proposed method is designed using the multiple output convolutional neural network (CNN). Unlike the conventional CFAR, the proposed estimator is easier to use because it does not require any additional information such as noise power. According to the simulation results, the proposed CNN improves the mean square error (MSE) by more than 5 times compared with the conventional CFAR, and the proposed estimator becomes more accurate as the number of transmitted OFDM symbols increases.

The Effective Binarization Method of Optical JTC for Multitarget Tracking (다중표적 추적을 위한 광 JTC의 효과적인 이진화 방법)

  • 이상이;서춘원;김은수
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.5
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    • pp.76-84
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    • 1994
  • Recently, Optical BJTC as a new approach for real-time multi-target tracking has been intensively studied. But the conventional system has some problems in the practical applications such as the false alarm and target missing and low correlation efficiency, and these poor performances are analyzed to be deeply dependent on the binarization method. So, in this paper, a new BJTC system which has the improved performances in target discrimination and diffraction efficiency is suggested, which is based on the JTPS having the same properties with those of the matched filter and new power spectrum binarization method to use effectively the high frequency components of the JTPS signal. Through the computer simulation and some experiments, the performances of the new BJTC tracking system are analyzed and proved to be superior to those of the conventional system baseds on Median method in multi- target tracking problems.

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A Combined Process Control Procedure by Monitoring and Repeated Adjustment

  • Park, Changsoon
    • Communications for Statistical Applications and Methods
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    • v.7 no.3
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    • pp.773-788
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    • 2000
  • Statistical process control (SPC) and engineering process control (EPC) are based on different strategies for processes quality improvement. SPC reduces process variability by detecting and eliminating special causes of process variation. while EPC reduces process variability by adjusting compensatory variables to keep the quality variable close to target. Recently there has been needs for a process control proceduce which combines the tow strategies. This paper considers a combined scheme which simultaneously applies SPC and EPC techniques to reduce the variation of a process. The process model under consideration is an integrated moving average(IMA) process with a step shift. The EPC part of the scheme adjusts the process back to target at every fixed monitoring intervals, which is referred to a repeated adjustment scheme. The SPC part of the scheme uses an exponentially weighted moving average(EWMA) of observed deviation from target to detect special causes. A Markov chain model is developed to relate the scheme's expected cost per unit time to the design parameters of he combined control scheme. The expected cost per unit time is composed of off-target cost, adjustment cost, monitoring cost, and false alarm cost.

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Determinants of Functional MicroRNA Targeting

  • Hyeonseo Hwang;Hee Ryung Chang;Daehyun Baek
    • Molecules and Cells
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    • v.46 no.1
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    • pp.21-32
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    • 2023
  • MicroRNAs (miRNAs) play cardinal roles in regulating biological pathways and processes, resulting in significant physiological effects. To understand the complex regulatory network of miRNAs, previous studies have utilized massivescale datasets of miRNA targeting and attempted to computationally predict the functional targets of miRNAs. Many miRNA target prediction tools have been developed and are widely used by scientists from various fields of biology and medicine. Most of these tools consider seed pairing between miRNAs and their mRNA targets and additionally consider other determinants to improve prediction accuracy. However, these tools exhibit limited prediction accuracy and high false positive rates. The utilization of additional determinants, such as RNA modifications and RNA-binding protein binding sites, may further improve miRNA target prediction. In this review, we discuss the determinants of functional miRNA targeting that are currently used in miRNA target prediction and the potentially predictive but unappreciated determinants that may improve prediction accuracy.

Acquisition Modeling of an Airborne Target for IR Target Tracking Simulation (적외선 표적 추적 시뮬레이션을 위한 공중 표적 포착 모델링)

  • 오정수;두경수;장성갑;서동선;최종수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.8B
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    • pp.1593-1600
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    • 1999
  • This paper describes the acquisition modeling of an airborne target for target tracking simulation of infrared homing missiles. The modeling, of which key technologies are the sub-modeling for target infrared signature, atmospheric transmission, and receiver characteristics, shows the acquisition process of an airborne target under various tracking conditions determined by line-of-sight, distance, and atmospheric conditions. We confirm the validity of the modeling by applying it to simulations concerned with target tracking. The modeling gives a guideline to determine an optimum detector and a defection band for effective discrimination of the target among false targets.

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MRAL Post Processing based on LS for Performance Improvement of Active Sonar Localization (소나 위치 추정 성능 향상을 위한 LS기반 MRAL 후처리 기법)

  • Jang, Eun-Jeong;Han, Dong Seog
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.9
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    • pp.172-180
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    • 2012
  • In multi-static sonar for detecting an underwater target, received signals contain the target echo, reverberation and clutter. Clutter and reverberation are main causes of increasing the false alarm rate. MRAL classifies received signals according to the spatial similarity, and it regards classified signal as reflected signals from a reflector. MRAL reduces the false alarm rate this way. However, the results of MRAL can have localization errors. In this paper, an MRAL post processing algorithm is proposed to reduce the localization errors with the least square (LS) method.

Optimal sensing period in cooperative relay cognitive radio networks

  • Zhang, Shibing;Guo, Xin;Zhang, Xiaoge;Qiu, Gongan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.12
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    • pp.5249-5267
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    • 2016
  • Cognitive radio is an efficient technique to improve spectrum efficiency and relieve the pressure of spectrum resources. In this paper, we investigate the spectrum sensing period in cooperative relay cognitive radio networks; analyze the relationship between the available capacity and the signal-to-noise ratio of the received signal of second users, the target probability of detection and the active probability of primary users. Finally, we derive the closed form expression of the optimal spectrum sensing period in terms of maximum throughput. We simulate the probability of false alarm and available capacity of cognitive radio networks and compare optimal spectrum sensing period scheme with fixed sensing period one in these performance. Simulation results show that the optimal sensing period makes the cognitive networks achieve the higher throughput and better spectrum sensing performance than the fixed sensing period does. Cooperative relay cognitive radio networks with optimal spectrum sensing period can achieve the high capacity and steady probability of false alarm in different target probability of detection. It provides a valuable reference for choosing the optimal spectrum sensing period in cooperative relay cognitive radio networks.