• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.1
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• pp.61-68
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• 2015

Noise reduction is necessary to compensate for the degradation of recognition performance by various types of noises. Among many noise reduction techniques using microphone array, generalized sidelobe canceller (GSC) has been widely applied to reduce nonstationary noises. The performance of GSC is directly affected by its adaptation mode controller (AMC). That is, accurate target speech detection is essential to guarantee the sufficient noise reduction in pure noise intervals and the less distortion in target speech intervals. Thus, this paper proposes an improved AMC design technique in which the power ratio of the output of fixed beamforming to that of blocking matrix is calculated frequency bandwise and probabilistically modeled by mixture Gaussians for each class. Experimental results show that the proposed algorithm outperforms conventional AMCs in receiver operating curves (ROC) and output SNRs.

• The Journal of the Korea Contents Association
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• v.21 no.1
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• pp.465-474
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• 2021

Corona-19, a disease caused by 'Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)', was declared a global pandemic by the World Health Organization (WHO) in March 2020, and a real-time polymerase chain reaction test is performed as a diagnostic test for screening and confirmation in most countries. However, not only the target genes and protocols differ by countries, but also the procedures for reading the diagnosis results are diverse, so the criteria for confirmed patients differ by country. Therefore, in this review, we discussed the target genes, test techniques, and diagnostic criteria for each country notified by WHO. And the specificity and sensitivity, limits of detection, positive and negative controls, false positive bacteria candidates, and specimens, and the specifics of the control setting were also described. In addition, the characteristics of Korea's test were compared to each country's one. Finally, in order to obtain the same diagnosis result for SARS-CoV-2 in the future, standardized diagnosis methods and result interpretations for Corona-19 diagnosis were proposed.

• Journal of Korea Society of Industrial Information Systems
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• v.14 no.5
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• pp.61-73
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• 2009

Many software reliability growth models(SRGM) have been proposed since the software reliability issue was raised in 1972. The technology to estimate and grow the reliability of developing S/W to target value during testing phase were developed using them. Most of these propositions assumed the S/W debugging testing efforts be constant or even did not consider them. A few papers were presented as the software reliability evaluation considering the testing effort was important afterwards. The testing effort forms which have been presented by this kind of papers were exponential, Rayleigh, Weibull, or Logistic functions, and one of these 4 types was used as a testing effort function depending on the S/W developing circumstances. I propose the methology to evaluate the SRGM using least square estimater and maximum likelihood estimater for those 4 functions, and then examine parameters applying actual data adopted from real field test of developing S/W.

• Journal of Advanced Navigation Technology
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• v.12 no.2
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• pp.132-138
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• 2008

Recently, many frequency sharing technology including CR (Cognitive Radio) technology have been studied actively because of frequency scarcity. For implementing CR systems, spectrum sensing technology plays key role. In IEEE 802.22 WRAN, the first standard aimed at Internet service in a TV channel with CR technology. This paper explained the various spectrum sensing schemes detecting narrowband ATSC signal in the IEEE 802.22 such as Energy detector, Spectral Correlation Sensing scheme, Covariance based Sensing algorithm and analyzed in terms of the probability of misdetection when the probability of false alarm is 10%. Based on simulation results, this paper proposed a duplex sensing scheme based on Energy detector and analyzed the capability of the proposed sensing scheme comparing with each sensing scheme.

• Aerospace Engineering and Technology
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• v.6 no.2
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• pp.21-28
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• 2007

The goal of this paper is to represent a technique of fault detection for the control surface as a base research of the fault tolerant control system for safety improvement of UAV. The real-time system identification based on the recursive Fourier Transform was implemented for the fault detection of the control surface and verified through the HILS and flight test. The failures of the control surface are detected by comparing the control derivatives in fault condition with the normal condition. As a result from the flight test, we have confirmed that the control derivatives of fault condition less than normal condition.

• Annual Conference of KIPS
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• 2005.05a
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• pp.789-792
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• 2005

최근 급격히 발전한 휴대폰은 다양한 기능을 가지고 있다. 그 중 디지털 카메라의 기능을 겸비한 휴대폰은 디지털 카메라의 판매량을 앞서고 있고, 메가픽셀의 고화소 디카폰의 개발로 대중화가 더욱 가속화되고 있다. 카메라폰을 응용한 연구분야로는 생체인식기술을 적용할 수 있으며, 본 논문은 제약이 많은 휴대폰 환경에서 홍채인식기술을 적용하기 위한 휴대폰 카메라로 취득된 얼굴영상에서의 눈 영역을 검출하는 방법을 제안한다. 얼굴영상에서 눈은 피부나 머리카락보다 빛에 대한 반사율이 높아 각막에 specular reflection이 생기게 되고, 동공은 눈의 다른 지역에 비해 흑화소가 많다는 특징을 가지고 있다. 이러한 두 가지 특징을 이용하여 동공 후보 영역을 선정하였고, 선정된 이진영상에서 수평 프로파일과 수직 프로파일을 적용하여 동공 후보 영역을 줄이면서 동공의 중심 위치를 검출한다. 본 연구는 휴대폰 환경을 고려하였기 때문에 최소한의 메모리 사용과 적은 연산량을 목표로 하여 눈의 위치를 검출 한다. 실험 결과, 입력 영상 내에 일정크기의 동공영역이 존재할 경우 높은 눈 영역 추출 성공률을 보이며, 본 연구에서 제안한 알고리즘을 실제 휴대폰에서 수행한 결과 평균571.6ms의 시간이 소요됨을 알 수 있었다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.10C
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• pp.987-992
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• 2002

In this paper, a new clock and data recovery circuit is proposed for the application of data communication systems requiring ㎓-range clock signals. The circuit is suitable for recovering NRZ data which is widely used for high speed data transmission in ㎓ ranges. The high frequency jitter is one of major performance-limiting factors in PLL, particularly when NRZ data patterns are used. A novel phase detector is able to suppress this noise, and stable clock generation is achieved. Futhermore, the phase detector has an adaptive delay cell removing the dead zone problem and has the optimal characteristics for fast locking. The proposed circuit has a convenience structure that can be easily extended to multi-channels. The circuit is designed based on CMOS 0.25㎛ fabrication process and verified by measurement result.

• The KIPS Transactions:PartB
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• v.12B no.7 s.103
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• pp.721-728
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• 2005

This paper suggests effective object detection system for moving objects with specified color and motion information. The proposed detection system includes the object extraction and definition process which uses MCN(Multiple Color Normalization) and MCWUPC(Moving Color Weighted Unmatched Pixel Count) computation to decide the existence of moving object and object segmentation technique using signature information is used to exactly extract the objects with high probability. Finally, real time detection system is implemented to verify the effectiveness of the technique and experiments show that the success rate of object tracking is more than $89\%$ of total 120 image frames.

• The Korean Journal of Mycology
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• v.44 no.2
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• pp.103-107
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• 2016

To establish a rapid and accurate detection of Phytophthora pinifolia, which is a quarantine pathogenic fungus in Korea, a species-specific primer was developed based on the ras-related protein (Ypt1) gene. Species-specific primer based on the DNA sequences of Ypt1 gene amplified 193 bp polymerase chain reaction (PCR) product for P. pinifolia. The primer pair yielded the predicted PCR product size exactly in testing with target pathogen DNAs, but not from the other 10 species of Phytophthora and 14 species of other phytopathogenic fungi. The primer pair also showed only the species-specific amplification curve on realtime PCR on target pathogen DNA. The detection sensitivity of real time PCR using species-specific primer pair was 10 to 100 times higher than conventional PCR, with 1 to $10pg/{\mu}L$.

• Journal of Broadcast Engineering
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• v.18 no.5
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• pp.680-690
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• 2013

In this paper, we propose a real-time temporal synchronization and compensation algorithm in stereoscopic video. Many temporal asynchronies are caused in the video editing stage and due to different transmission delays. These temporal asynchronies can degrade the perceived 3D quality. The goal of temporal alignment is to detect and to measure the temporal asynchrony and recover synchronization of the two video streams. In order to recover synchronization of the two video streams, we developed a method to detect asynchronies between the left and the right video streams based on a novel spatiogram information, which is a richer representation, capturing not only the values of the pixels but their spatial relationships as well. The proposed novel spatiogram additionally includes the changes of the spatial color distribution. Furthermore, we propose a block-based method for detection of the pair frame instead of one frame-based method. Various 3D experiments demonstrate the effectiveness of the proposed method.