• Title/Summary/Keyword: Maximum detection range

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A Simulator for Radar Performance Evaluation in a Far-Field Test Range (원방계 조건하에서의 레이다 성능평가를 위한 시뮬레이터)

  • Kil, Min-Young;Myung, Noh-Hoon
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2005.11a
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    • pp.33-38
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    • 2005
  • In this paper, a simulator for radar performance evaluation in a far-field test range is proposed, which can forecast maximum detection range, minimum detection range, number of test trials, resolution (range, azimuth, elevation) with input parameters before radar performance test and process results after. The proposed simulator is designed by Microsoft Foundation Class (MFC) of VC++ 6.0.

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A Study on the Maximum Detection Range Calculation Model of the Pulse-Radar (펄스 레이더의 최대탐지거리 산출 모델연구)

  • Chae, Kwang-Pyo
    • Journal of the military operations research society of Korea
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    • v.6 no.2
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    • pp.27-46
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    • 1980
  • Computer model for calculating the maximum detection range of the pulse radar used for surface surveillance is developed, and the detailed procedures of each theoretical step are discussed. The quantity of radar antenna's receiving energy, transmitting energy and noise level are compared in this model. All the calculation steps are programmed in BASIC language. Finally, I have found the output of this model well matched with the some experimental results.

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Dwell Time Optimization of Alert-Confirm Detection for Active Phased Array Radars

  • Kim, Eun Hee;Park, JoonYong
    • Journal of electromagnetic engineering and science
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    • v.19 no.2
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    • pp.107-114
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    • 2019
  • Alert-confirm detection is a highly efficient method to improve phased array radar search performance. It comprises sequential detection in two steps: alert detection, in which a target is detected at a low detection threshold, and confirm detection, which is triggered by alert detection with a longer dwell time to minimize false alarms. This paper provides a design method for applying the alert-confirm detection to multifunctional radars. We find optimum dwell times and false alarm probabilities for each alert detection and confirm detection under the dual constraints of total false alarm probability and maximum allowable dwell time per position. These optimum values are expressed as a function of the mean new target appearance rate. The proposed alert-confirm detection increases the maximum detection range even with a shorter frame time than that of uniform scanning.

Transmission Power Range based Sybil Attack Detection Method over Wireless Sensor Networks

  • Seo, Hwa-Jeong;Kim, Ho-Won
    • Journal of information and communication convergence engineering
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    • v.9 no.6
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    • pp.676-682
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    • 2011
  • Sybil attack can disrupt proper operations of wireless sensor network by forging its sensor node to multiple identities. To protect the sensor network from such an attack, a number of countermeasure methods based on RSSI (Received Signal Strength Indicator) and LQI (Link Quality Indicator) have been proposed. However, previous works on the Sybil attack detection do not consider the fact that Sybil nodes can change their RSSI and LQI strength for their malicious purposes. In this paper, we present a Sybil attack detection method based on a transmission power range. Our proposed method initially measures range of RSSI and LQI from sensor nodes, and then set the minimum, maximum and average RSSI and LQI strength value. After initialization, monitoring nodes request that each sensor node transmits data with different transmission power strengths. If the value measured by monitoring node is out of the range in transmission power strengths, the node is considered as a malicious node.

Unsupervised Change Detection of Hyperspectral images Using Range Average and Maximum Distance Methods (구간평균 기법과 직선으로부터의 최대거리를 이용한 초분광영상의 무감독변화탐지)

  • Kim, Dae-Sung;Kim, Yong-Il;Pyeon, Mu-Wook
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.29 no.1
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    • pp.71-80
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    • 2011
  • Thresholding is important step for detecting binary change/non-change information in the unsupervised change detection. This study proposes new unsupervised change detection method using Hyperion hyperspectral images, which are expected with data increased demand. A graph is drawn with applying the range average method for the result value through pixel-based similarity measurement, and thresholding value is decided at the maximum distance point from a straight line. The proposed method is assessed in comparison with expectation-maximization algorithm, coner method, Otsu's method using synthetic images and Hyperion hyperspectral images. Throughout the results, we validated that the proposed method can be applied simply and had similar or better performance than the other methods.

Performance prediction of gamma electron vertex imaging (GEVI) system for interfractional range shift detection in spot scanning proton therapy

  • Kim, Sung Hun;Jeong, Jong Hwi;Ku, Youngmo;Jung, Jaerin;Kim, Chan Hyeong
    • Nuclear Engineering and Technology
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    • v.54 no.6
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    • pp.2213-2220
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    • 2022
  • The maximum dose delivery at the end of the beam range provides the main advantage of using proton therapy. The range of the proton beam, however, is subject to uncertainties, which limit the clinical benefits of proton therapy and, therefore, accurate in vivo verification of the beam range is desirable. For the beam range verification in spot scanning proton therapy, a prompt gamma detection system, called as gamma electron vertex imaging (GEVI) system, is under development and, in the present study, the performance of the GEVI system in spot scanning proton therapy was predicted with Geant4 Monte Carlo simulations in terms of shift detection sensitivity, accuracy and precision. The simulation results indicated that the GEVI system can detect the interfractional range shifts down to 1 mm shift for the cases considered in the present study. The results also showed that both the evaluated accuracy and precision were less than 1-2 mm, except for the scenarios where we consider all spots in the energy layer for a local shifting. It was very encouraging results that the accuracy and precision satisfied the smallest distal safety margin of the investigated beam energy (i.e., 4.88 mm for 134.9 MeV).

Effectiveness Analysis for Survival Probability of a Surface Warship Considering Static and Mobile Decoys (부유식 및 자항식 기만기의 혼합 운용을 고려한 수상함의 생존율에 대한 효과도 분석)

  • Shin, MyoungIn;Cho, Hyunjin;Lee, Jinho;Lim, Jun-Seok;Lee, Seokjin;Kim, Wan-Jin;Kim, Woo Shik;Hong, Wooyoung
    • Journal of the Korea Society for Simulation
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    • v.25 no.3
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    • pp.53-63
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    • 2016
  • We consider simulation study combining static and mobile decoys for survivability of a surface warship against torpedo attack. It is assumed that an enemy torpedo is a passive acoustic homing torpedo and detects a target within its maximum target detection range and search beam angle by computing signal excess via passive sonar equation, and a warship conducts an evasive maneuvering with deploying static and mobile decoys simultaneously to counteract a torpedo attack. Suggesting the four different decoy deployment plans to achieve the best plan, we analyze an effectiveness for a warship's survival probability through Monte Carlo simulation, given a certain experimental environment. Furthermore, changing the speed and the source level of decoys, the maximum torpedo detection range of warship, and the maximum target detection range of torpedo, we observe the corresponding survival probabilities, which can provide the operational capabilities of an underwater defense system.

Comparative analysis of Bayesian and maximum likelihood estimators in change point problems with Poisson process

  • Kitabo, Cheru Atsmegiorgis;Kim, Jong Tae
    • Journal of the Korean Data and Information Science Society
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    • v.26 no.1
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    • pp.261-269
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    • 2015
  • Nowadays the application of change point analysis has been indispensable in a wide range of areas such as quality control, finance, environmetrics, medicine, geographics, and engineering. Identification of times where process changes would help minimize the consequences that might happen afterwards. The main objective of this paper is to compare the change-point detection capabilities of Bayesian estimate and maximum likelihood estimate. We applied Bayesian and maximum likelihood techniques to formulate change points having a step change and multiple number of change points in a Poisson rate. After a signal from c-chart and Poisson cumulative sum control charts have been detected, Monte Carlo simulation has been applied to investigate the performance of Bayesian and maximum likelihood estimation. Change point detection capacities of Bayesian and maximum likelihood estimation techniques have been investigated through simulation. It has been found that the Bayesian estimates outperforms standard control charts well specially when there exists a small to medium size of step change. Moreover, it performs convincingly well in comparison with the maximum like-lihood estimator and remains good choice specially in confidence interval statistical inference.

Detection Performance of Logarithmic Receiver (대수수신계통의 탐색특성)

  • 윤현보
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.6 no.1
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    • pp.27-31
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    • 1981
  • This paper deals with the variation of the effective detectability factor fo logarithmic receiver in noise interference environment. The computed results as a function of maximum detection range and jamming range were compared with the effective detectability factor for linear receiver. Even though the logarithmic receiver has a wide dynamic characteristics, it is found that the effective detectability factor being reduced about 15% than the linear receiver at 100 KM range.

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The Pitch Detection Using Variable LPF (Variable LPF에 의한 피치검출)

  • 백금란
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1993.06a
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    • pp.88-92
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    • 1993
  • In speech signal processing, it is necessary to detect exactly the pitch. The algorithms of pitch extraction which have been proposed until now are difficult to detect pitches over wide range speech signals. Thus we propose a new algorithm which uses the G-peak extraction to do it. It is the method that finds the most MZI(maximum zero-crossing interval) at each frame and convolve it with speech signal ; this is the same with passing speech signals to variable LPF. Finally we obtained the pitch, improve the accuracy of pitch detection and extract it with the high speed.

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