• Korean Journal of Culture and Social Issue
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• v.14 no.4
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• pp.103-117
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• 2008

The polygraph test administered by the Korean Prosecutors Office for crime investigations customarily uses the score of -12 as the cutoff point separating the subjects who lie from those who tell the truth. The criterion used by the KPO is different from the one (-13) suggested by Backster (1963) who invented the particular method for lie detection. Based on the signal detection theory applied to the real polygraph test data obtained from real crime suspects by the KPO, the present study identified the score of -8 as an optimal criterion resulting in the highest overall accuracy of the polygraph test. The classification of the subjects with the score of -8 as the criterion resulted in the highest accuracy (83.17%) compared with the accuracies of classifications with the Backster's criterion (76.24%) and the KPO's criterion (80.20%). However, the new criterion was also found to result in more false-positive cases. Based on the results from the present study, it was recommended to use the score of -8 as the criterion when the overall accuracy is important but the score of -12 or -13 when avoiding false-positive is more important than securing the overall accuracy.

• Journal of the Korean Data and Information Science Society
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• v.22 no.2
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• pp.197-206
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• 2011

The ability to detect online abnormal events in signals is essential in many real-world signal processing applications. In order to detect abnormal events, previously known algorithms require an explicit signal statistical model, and interpret abnormal events as statistical model abrupt changes. In general, maximum likelihood and Bayesian estimation theory to estimate well as detection methods have been used. However, the above-mentioned methods for robust and tractable model, it is not easy to estimate. More freedom to estimate how the model is needed. In this paper, we investigate a machine learning, descriptor-based approach that does not require a explicit descriptors statistical model, based on support vector machines are known to be robust statistical models and a sequential optimal algorithm online support vector machine is introduced.

• Current Industrial and Technological Trends in Aerospace
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• v.7 no.1
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• pp.113-118
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• 2009

In this paper, we described the model of noise, target for tracking radar and range tracking, angle tracking, and Doppler frequency tracking for target acquisition and tracking. Target signal as well as the noise signal is modeled as random process varying with elapsed time. This paper addresses three areas of radar target tracking: range tracking, angle tracking, and Doppler frequency tracking. In general, range tracking is prerequisite to and inherent in both angle and Doppler frequency tracking systems. First, we introduced the several range tracking and described techniques for achieving range tracking. Second, we described the radar angle tracking techniques including conical scan, sequential lobing, and monopulse. Finally, we presented concepts and techniques for Doppler frequency tracking for several radar types.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.155-162
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• 2020

In this paper, we present a radiation compensation method and experiment method for two-dimensional direction finding by elevation and azimuth angles of broadband GPS signal, and then produce experimental results. Previous studies have performed direction finding by only using the azimuth angle of the detected signal. So, the compensation table utilizes compensation data by azimuth angles only. However, the presented method in this study has compensation data by azimuth and elevation angles for two-dimensional direction finding. Because of direction finding systems and applications are diversified, recently. So, we present a two-dimensional radiation compensation method. For evaluation of the presented compensation method, we calculate the ideal phase differences on the antenna for two-dimensional direction finding and simulate phase differences using a FEKO EM simulator. Subsequently, we analyze experimental data by radiation compensation experiments using the presented compensation method in an anechoic chamber.

• Journal of IKEEE
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• v.24 no.4
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• pp.921-930
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• 2020

The Counter-battery radar estimates the origin and impact point of the artillery by tracking the trajectory of the shell. In addition, it has the ability of identifying the type of weapon. Depending on the position between the shell and the radar, the detected signals appear differently. This has ambiguity to distinguish the type of shells. This paper compares fuzzy logic and artificial intelligence, which classifies type of shell using the parameter of signal processing step. According to the research result, artificial intelligence can improve identification rate of type of shell. The data used in the experiment was obtained from a live fire detection test.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.12a
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• pp.309-312
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• 2002

본 논문에서는 오디오 워터 마킹 기법을 제안한다. 이 방법은 5차 웨이브릿 변환을 이용한sync 탐지 기법을 제안한다. 이 원리를 Zuicker의 인간청각모델의 한계 밴드이론을 이용한다. 그리고 워터마킹 검출에는 정점 탐지 기법에서 많이 이용하는 에너지와 제로통과 비율을 이용하여 워터마크를 검출한다 실험을 통하여 본 알고리즘이 mp3압축에 강인할 뿐 아니라 디지털에서 아날로그신호로 바꾸고 다시 디지털 신호로 바꾸는 아날로그 공격에 시간영역이나 DCT영역에서 워터마킹을 행하는 것보다 본 알고리즘이 강인함을 보인다 본 오디오 알고리즘은 음악에 연동하는 전기기기를 구성할 때 유용한 알고리즘이 될 수 있다. 즉 음악에 워터마크를 삽입하여 이 워터마크를 전기기기 동작제어 비트열로 이용할 수 있을 것이다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.12
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• pp.2628-2635
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• 2010

This paper analyzes the detection probability of FMCW (Frequency Modulated Continuous Wave) radar based on Doppler frequency and analog-digital converter bit and designs and implements signal processing part of FMCW radar. For performance evaluation, the FMCW radar system consists of a transmitted part and a received part and uses AWGN channel. The system model is verified through analysis and simulation. Frequency offset occurs in the received part caused by the mismatching between the received signal and the reference signal. In case of Doppler frequency less than about 38KHz, performance degradation of detection does not occur in FMCW radar with 75cm resolution The analog-digital converter needs at least 6 bit in order not to degrade the detection probability. And, we design and implement digital signal processing part based on DDS chip of digital transmitted signal generator for FMCW radar.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.5
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• pp.786-795
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• 1999

To detect the precise of arrival of target signal in real ocean environments, Inverse beamformnig(IBF) solutions to the Inverse beamforming integral equation are surveyed theoretically and the performance properties of the IBF are analyzed with simulations. IBF-Cardioid beamforming algorithm is proposed for port/starboard discrimination and the performance gains are studied with simulations. It is shown that IBF has a 3 dB array noise gain advantage over CBF under ideal conditions. This 3 dB array noise gain advantage is proven by theocratical studies and simulations. This array noise gain advantage leads to a minimum detectable level advantage for IBF output compared with CBF output. The fact that the IBF beamwidth is narrower than the CBF beamwidth by a factor of 0.68 proves the performance of detection and spatial resolution improvement. Comparing the simulation results of IBF-Cardioid beamforming and Conventional Cardioid beamforming, it is shown that IBF-Cardioid beamformer have performance enhancement in minimum detection level, detection accuracy and resolution.

• The Journal of the Acoustical Society of Korea
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• v.43 no.2
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• pp.145-151
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• 2024

Recently, ship hull-mounted passive sonar system solution is needed in the perspective of improving target detection and elimination of vibration-induced noise. Our research team suggests acousticvibration matching method using front and rear signal of a sensor as the improvement of the problem above. Thus in this paper, theoretical background about matching method and its application on finite element method based multi-physics simulation are described. Furthermore, it is shown that target detection and hull vibration performance are improved by using matching method under the condition of our sensor system. Finally, practicality and future research are discussed.

• Proceedings of the Korea Multimedia Society Conference
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• 2000.11a
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• pp.455-458
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• 2000

인공 신경망은 체계적인 알고리즘으로 풀기 어려운 문제들을 해결하는데 사용되어오고 있다. 이는 인간의 뇌세포가 외부자극에 대해 반응하는 과정을 컴퓨터 시스템 상에서 구현한 것으로 새 인간과 컴퓨터의 상호작용을 연구하는데 흥미로운 접근방식이다. 본 논문에서는 신경망의 접근방법을 이용하여 인간행위 인식시스템을 구현하였다. 신경망을 이용해 구현된 컴퓨터 인식 시스템이 인간의 두 가지 정서 하에서 일어난 세가지 서로 다른 행동을 보고 행위자의 성별이나 강정상태를 얼마나 인식해낼 수 있는지 실험해 보았다. 특히, 성별 인식 실험에서는 신호탐지 이론에서 사용하는 인장도(discriminability)를 이용해 사람에 대한 이 시스템의 효율도를 계산하였다