• Title/Summary/Keyword: False-alarm rate

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Improvement of Domain-specific Keyword Spotting Performance Using Hybrid Confidence Measure (하이브리드 신뢰도를 이용한 제한 영역 핵심어 검출 성능향상)

  • 이경록;서현철;최승호;최승호;김진영
    • The Journal of the Acoustical Society of Korea
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    • v.21 no.7
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    • pp.632-640
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    • 2002
  • In this paper, we proposed ACM (Anti-filler confidence measure) to compensate shortcoming of conventional RLJ-CM (RLJ-CM) and NCM (normalized CM), and integrated proposed ACM and conventional NCM using HCM (hybrid CM). Proposed ACM analyzes that FA (false acceptance) happens by the construction method of anti-phone model, and presumed phoneme sequence in actuality using phoneme recognizer to compensate this. We defined this as anti-phone model and used in confidence measure calculation. Analyzing feature of two confidences measure, conventional NCM shows good performance to FR (false rejection) and proposed ACM shows good performance in FA. This shows that feature of each other are complementary. Use these feature, we integrated two confidence measures using weighting vector α And defined this as HCM. In MDR (missed detection rate) 10% neighborhood, HCM is 0.219 FA/KW/HR (false alarm/keyword/hour). This is that Performance improves 22% than used conventional NCM individually.

Transmission of Channel Error Information over Voice Packet (음성 패킷을 이용한 채널의 에러 정보 전달)

  • 박호종;차성호
    • The Journal of the Acoustical Society of Korea
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    • v.21 no.4
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    • pp.394-400
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    • 2002
  • In digital speech communications, the quality of service can be increased by speech coding scheme that is adaptive to the error rate of voice packet transmission. However, current communication protocol in cellular and internet communications does not provide the function that transmits the channel error information. To solute this problem, in this paper, new method for real-time transmission of channel error information is proposed, where channel error information is embedded in voice packet. The proposed method utilizes the pulse positions of codevector in ACELP speech codec, which results in little degradation in speech quality and low false alarm rate. The simulations with various speech data show that the proposed method meets the requirement in speech quality, detection rate, and false alarm rate.

Development of Incident Detection Model Using Compression Wave Test Module (압축파 검사 모듈을 이용한 돌발상황 검지 모형의 개발)

  • Lee, Hwan-Pil;Kim, Nam-Sun;Oh, Young-Tae;Kim, Soo-Hee
    • Journal of Korean Society of Transportation
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    • v.22 no.6
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    • pp.77-88
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    • 2004
  • This study aims at developing the model that is able to detect the compression wave, which is included as a similar situation in incidents, that causes false applicable to the similar character such as incidents in the incident detection model for expressways. In this study, it has been checked whether the number of false alarms is decreased or not by modularizing this model for being able to applicable to other models such as DES and DELOS, etc. which do not perform the compression wave test based on the compression wave test process of APID model which has been being used in the expressway traffic management system currently. The evaluation in this study focuses on the sensitivity of the model and the results analysis is performed classified by each polling cycle. And how well these models are working is evaluated by each polling cycle. In addition to this, the detection rate, the false alarm rate and the average detection time in both the existing models and the model in this study are calcuated. As a result of appling the model in this study, it is found that the false alarm rate is improved through the reasonable decrease in the number of false alarm frequencies and there are not remarkable changes concerning the detection rate and the average detection time. To sum up, it is expected that a good number of improvement effects will be occurred when this model is applied to the actual expressway traffic management system.

Performance Analysis of an Adaptive Hybrid Search Code Acquisition Algorithm for DS-CDMA Systems (DS-CDMA 시스템을 위한 적응 혼합 검색형 동기획득 알고리즘의 성능 분석)

  • Park Hyung rae;Yang Yeon sil
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.3C
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    • pp.83-91
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    • 2005
  • We analyze the performance of an adaptive hybrid search code acquisition algorithm for direct-sequence code division multiple access (DS-CDMA) systems under slowly-moving mobile environments. The code acquisition algorithm is designed to provide the desired feature of constant false alarm rate (CFAR) to cope with nonstationarity of the interference in CDMA forward links. An analytical expression for the mean acquisition time is first derived and the probabilities of detection, miss, and false alarm are then obtained for frequency-selective Rayleigh fading environments. The fading envelope of a received signal is assumed to be constant over the duration of post-detection integration (PDI), considering slow fading environments. Finally, the performance of the designed code acquisition algorithm shall be evaluated numerically to examine the effect of some design parameters such as the sub-window size, size of the PDI, decision threshold, and so on, considering cdma2000 environments.

Improvement of Keyword Spotting Performance Using Normalized Confidence Measure (정규화 신뢰도를 이용한 핵심어 검출 성능향상)

  • Kim, Cheol;Lee, Kyoung-Rok;Kim, Jin-Young;Choi, Seung-Ho;Choi, Seung-Ho
    • The Journal of the Acoustical Society of Korea
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    • v.21 no.4
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    • pp.380-386
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    • 2002
  • Conventional post-processing as like confidence measure (CM) proposed by Rahim calculates phones' CM using the likelihood between phoneme model and anti-model, and then word's CM is obtained by averaging phone-level CMs[1]. In conventional method, CMs of some specific keywords are tory low and they are usually rejected. The reason is that statistics of phone-level CMs are not consistent. In other words, phone-level CMs have different probability density functions (pdf) for each phone, especially sri-phone. To overcome this problem, in this paper, we propose normalized confidence measure. Our approach is to transform CM pdf of each tri-phone to the same pdf under the assumption that CM pdfs are Gaussian. For evaluating our method we use common keyword spotting system. In that system context-dependent HMM models are used for modeling keyword utterance and contort-independent HMM models are applied to non-keyword utterance. The experiment results show that the proposed NCM reduced FAR (false alarm rate) from 0.44 to 0.33 FA/KW/HR (false alarm/keyword/hour) when MDR is about 8%. It achieves 25% improvement of FAR.

TOA Estimation Technique for IR-UWB Based on Homogeneity Test

  • Djeddou, Mustapha;Zeher, Hichem;Nekachtali, Younes;Drouiche, Karim
    • ETRI Journal
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    • v.35 no.5
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    • pp.757-766
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    • 2013
  • This paper deals with the estimation of the time of arrival (TOA) of ultra-wideband signals under IEEE 802.15.4a channel models. The proposed approach is based on a randomness test and consists of determining whether an autoregressive (AR) process modeling an energy frame is random or not by using a distance to measure the randomness. The proposed method uses a threshold that is derived analytically according to a preset false alarm probability. To highlight the effectiveness of the developed approach, simulation setups as well as real data experiments are conducted to assess the performance of the new TOA estimation algorithm. Thereby, the proposed method is compared with the cell averaging constant false alarm rate technique, the threshold comparison algorithm, and the technique based on maximum energy selection with search back. The obtained results are promising, considering both simulations and collected real-life data.

Statistical Prediction of False Alarm Rates in Automatic Vision Inspection System (결함크기 측정오차로 인한 오검률의 통계적 예측)

  • Joo, Young-Bok;Huh, Kyung-Moo;Park, Kil-Houm;Lee, Gyu-Bong;Han, Chan-Ho
    • Proceedings of the IEEK Conference
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    • 2009.05a
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    • pp.163-165
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    • 2009
  • Automatic Vision Inspection(AVI) systems automatically detect defect features and measure their sizes via camera vision. It is important to predict the performance of an AVI to meet customer's specification in advance. In this paper, we propose a statistical method for prediction of false alarm rate regarding inconsistency of defect size measuremet process. We only need are a simple experimental trial for repeated defect size measurement test. The statistical features from the experiement are utilized in the prediction process. Therefore, the proposed method is swift and easy to implement and use. The experiment shows a close prediction compared to manual inspection results.

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Statistical Prediction of False Alarm Rates in Automatic Vision Inspection System (자동결함 검출시스템에서 결함크기 측정오차로 인한 오검률의 통계적 예측)

  • Joo, Young-Bok;Huh, Kyung-Moo;Park, Kil-Houm
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.9
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    • pp.906-908
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    • 2009
  • AVI (Automatic Vision Inspection) systems automatically detect defect features and measure their sizes via camera vision. It is important to predict the performance of an AVI to meet customer's specification in advance. Also the prediction can indicate the level of current performance of an AVI system. In this paper, we propose a statistical method for prediction of false alarm rate regarding inconsistency of defect size measurement process. For this purpose, only simple experiments are needed to measure the defect sizes for certain number of times. The statistical features from the experiment are utilized in the prediction process. Therefore, the proposed method is swift and easy to implement and use. The experiment shows a close prediction compared to manual inspection results.

Analysis of GNSS Signal Acquisition Performance Spreading Zadoff-Chu Codes

  • Jo, Gwang Hee;Choi, Yun Sub;Lim, Deok Won;Lee, Sang Jeong
    • Journal of Positioning, Navigation, and Timing
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    • v.8 no.1
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    • pp.13-18
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    • 2019
  • This paper analyzes the signal acquisition performance of the legacy GNSS spreading codes and a polyphase code. The code length and chip rate of a polyphase code are assumed to be same as those of the GPS L1 C/A and Galileo E1C codes. The autocorrelation and cross correlation characteristics are analyzed. In addition, a way to calculate a more accurate probability of false alarm for a code with sidelobe non-zero auto-correlation function is proposed. Finally, we estimate the probability of detection and the mean acquisition time for a given signal strength and the probability of false alarm.

A Color Video Flame Detection Method based on Wavelet Transform to Remove Flickering Non-Flame Detection (점멸성 비화염 검출을 제거하는 웨이블릿변환 기반의 컬러영상 화염 검출 방법)

  • Sanjeewa, Nuwan;Lee, Hyun-Sul;Kim, Won-Ho
    • Journal of Satellite, Information and Communications
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    • v.8 no.4
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    • pp.89-94
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    • 2013
  • This paper presents color video flame detection algorithm based on wavelet transform to remove detection of flickering non-flame objects. Conventional flame detection algorithms consist of simple or mixed functions using colors, temporal and spatial characteristics. But those algorithms detect non-flame objects as flame regions sometimes. False alarm reasons are flame-like objects with regular flickering lights such as car signal lamps, alarm lights etc. The proposed algorithm is to reduce false detection which is occurred in periodic flickering lights. At first, It segments the candidate flame regions by using frame difference, flame colors. Then it distinguish flame regions and non flame regions including flickering car lights by analyzing wavelet coefficients. Computer simulation results showed that the proposed algorithm removes false detection due to the periodic flickering lamps by performing 97.9% of correct detection rate while false detection rate is 7.3%.