• Journal of Microbiology and Biotechnology
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• v.33 no.1
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• pp.83-95
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• 2023

These days, bacterial detection methods have some limitations in sensitivity, specificity, and multiple detection. To overcome these, novel detection and identification method is necessary to be developed. Recently, NGS panel method has been suggested to screen, detect, and even identify specific foodborne pathogens in one reaction. In this study, new NGS panel primer sets were developed to target 13 specific virulence factor genes from five types of pathogenic Escherichia coli, Listeria monocytogenes, and Salmonella enterica serovar Typhimurium, respectively. Evaluation of the primer sets using singleplex PCR, crosscheck PCR and multiplex PCR revealed high specificity and selectivity without interference of primers or genomic DNAs. Subsequent NGS panel analysis with six artificially contaminated food samples using those primer sets showed that all target genes were multi-detected in one reaction at 10⁸-10⁵ CFU of target strains. However, a few false-positive results were shown at 10⁶-10⁵ CFU. To validate this NGS panel analysis, three sets of qPCR analyses were independently performed with the same contaminated food samples, showing the similar specificity and selectivity for detection and identification. While this NGS panel still has some issues for detection and identification of specific foodborne pathogens, it has much more advantages, especially multiple detection and identification in one reaction, and it could be improved by further optimized NGS panel primer sets and even by application of a new real-time NGS sequencing technology. Therefore, this study suggests the efficiency and usability of NGS panel for rapid determination of origin strain in various foodborne outbreaks in one reaction.

• MALSORI
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• no.43
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• pp.151-161
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• 2002

This study presents performance analysis results of speaker adaptation for keyword spotting system. In this paper, we implemented MLLR (Maximum Likelihood Linear Regression) method on our middle size vocabulary keyword spotting system. This system was developed for directory services of universities and colleges. The experimental results show that speaker adaptation reduces the false alarm rate to 1/3 with the preservation of the mis-detection ratio. This improvement is achieved when speaker adaptation is applied to not only keyword models but also non-keyword models.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.5
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• pp.416-425
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• 2013

A hybrid PN code phase acquisition system based on a least-mean-square adaptive filter, interpreted as a channel estimator is proposed and analyzed for direct-sequence spread-spectrum systems under frequency selective Rayleigh fading channels. Closed form expressions are derived for the filter tap weights and detection/false alarm probabilities. Compared to previously proposed systems, the proposed system achieves smaller mean acquisition times, is more robust to the operating signal-to-noise ratio and allows for multiplication free tap weight updates.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.149-150
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• 2012

We have created new catalogues of AKARI/IRC $2-24{\mu}m$ North Ecliptic Pole Deep survey through new methods of image analysis. In the new catalogues the number of false detection decreased by a factor of 10 and the number of objects detected in multiple bands increased by more than 1,500 compared to the previous work. In this proceedings the new methods of image analysis and the performance of the new catalogues are described.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.1A
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• pp.41-48
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• 2011

This paper proposes an efficient code acquisition scheme for direct-sequence spread spectrum (DSSS) based real-time locating systems (RTLS). The proposed scheme employs multiple bit integration to significantly decrease false alarms when no packet signal is transmitted and increase the detection probability when the RTLS tags are excited. The performance of the proposed code acquisition scheme is analyzed and numerically evaluated, and compared with those of single-dwell and traditional double-dwell code acquisition schemes. The simulation results show that the proposed multiple-bit integration scheme outperforms single-dwell and double-dwell schemes.

• The Journal of the Acoustical Society of Korea
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• v.18 no.7
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• pp.3-9
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• 1999

In this paper, the characteristics of LFM and CW signals in active sonar environment is investigated. CA, OS and TM CFAR processors are applied to the received CW/LFM signals which are plotted in the range/doppler domain. The performances of detection are analyzed. Particularly, using the real data, we certified that the results of the experiments are identical with the theoretical performance.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.05a
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• pp.3-8
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• 2005

위성영상을 이용한 산불탐지기법은 단순한 화재의 유무뿐만 아니라 온도, 면적, 상태 등과 같은 다양한 정보를 얻을 수 있는 수준으로 개발되었다. 하지만 실제 적용결과에 있어서는 서로 다른 탐지결과를 보이기 때문에 어떤 탐지기법을 선택하고 기법에 사용되는 임계값들을 어떻게 결정해야 하는가라는 문제점이 발생한다. 본 연구에서는 의사결정기법을 이용하여 개별 탐지기법의 결과를 분석하여 최적해를 얻고자 하였다. 이를 위하여 국내에서 발생한 산불에 주요 탐지기법을 적용, 정확도를 평가한 후 의사결정기법을 적용하여 보다 정확한 결과를 얻는 연구를 수행하였다. 그 결과 단일 탐지기법에서 발생하는 오류(false alarm)을 일정부분 보완할 수 있었다. 하지만 충분한 실측자료가 부족하여 정확한 평가 및 검증에는 한계가 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.2
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• pp.550-565
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• 2018

Cognitive radio technology is still the key technology of future mobile communication systems. Previous studies have focused on improving spectrum utilization and less energy consumption. In this paper, we propose an Overhead Reduced Scheme (ORS) for green cooperative spectrum sensing. Compared to traditional cooperative sensing scheme, ORS scheme divides the sensing time into three time slots and selects the best multi-mode user to report decisions. In consideration of reporting channel deviation, we derive closed-form expressions for detection probability and false alarm probability of ORS scheme based on Rayleigh fading channel. Simulation results show that ORS scheme can improve the perception accuracy while reducing the perceived delay and energy consumption in the process of perception, so as to realize the green communication.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04c
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• pp.247-249
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• 2003

일반적으로 방사선 의사들(radialogists)이 폐 결절(pulmonary nodule)을 탐지하는 데는 실제적으로 30% 의 실패율을 가진다고 알려져 있다. 만약 자동화된 시스템이 흉부 영상에서 의심스런 결절들의 위치들을 방사선 의사에게 알려줄 수 있다면 잘못 판단되는 결절들의 수를 잠재적으로 줄일 수 있다. 그리하여 기존의 시스템들은 처리가 어려운 X 선 영상을 좀 더 다루기 쉬운 상태로 바꿔주기 위하여 원래의 영상에 수축(erosion)과 확장(dilation)을 연이어서 행하는 형태학적 필터링(morphological filtering) 처리를 행한다. 그런 다음 결절의 특징을 가려낼 수 있는 추출 기술들을 나름대로 행한다. 그러나, 이 형태학적 필터링 처리는 상당한 처리 시간을 필요로 한다. 이에 본 논문은 형태학적 필터링 처리를 행하지 않고 원래의 흉부 X 선 영상으로부터 직접 결절의 의심지역들을 추출한 후 두가지 특징 추출기술들을 적용시킨다. 그리하여 본 시스템은 결절의 정확한 판독이 어려운 폐의 X 선 영상에 적용되어 false-positive 들을 효과적으로 줄임으로써 보다 효율적인 폐 결절의 추출를 가능하게 하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06b
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• pp.79-82
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• 2011

무인기용 비행제어 소프트웨어는 인터럽트 핸들러에서 비결정적인 수행결과를 조래하는 경합이 발생될 수 있다. 이러한 유형의 경합을 탐지하기 위한 기존 방법은 원시 프로그램의 인터럽트 핸들러를 스레드로 변환하여 정적 경합탐지 도구를 사용하므로 프로그램 수행 시 실제 발생하지 않는 부정확한 경합(false positives)를 보고한다. 본 연구는 부정확한 경합 보고를 줄이기 위해서 원시 프로그램을 POSIX 실시간 스레브 프로그램으로 변환하고 Lockset기반 탐지기법 의해서 탐지된 공유변수를 대상으로 Happens-before 관계 분석기법을 이용하여 경합을 탐지하는 동적 경합탐지 도구를 사용한다. 제시된 방법의 실험을 위해서 Knob Assembly에 탑재되는 비행제어 소프트웨어를 대상으로 정적 경합탐지 도구와 동적 경합탐지 도구의 경합탐지 결과를 비교 분석한다.