• Title/Summary/Keyword: Auto-correlation

Search Result 394, Processing Time 0.026 seconds

On optimal correction of gunfire errors (포 사격오차의 최적 수정에 관한 연구)

  • 이양원;김영주;김경기;김경기
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1989.10a
    • /
    • pp.109-112
    • /
    • 1989
  • Gun system operation is represented as a first-order Markov process, and an optimum linear filter is derived for closed-loop control of mean square error. Potential improvement is then estimated by contrasting the variance in performance and the auto correlation for open-loop system with that for the optimum linearly corrected process.

  • PDF

Training-Based Noise Reduction Method Considering Noise Correlation for Visual Quality Improvement of Recorded Analog Video (녹화된 아날로그 영상의 화질 개선을 위한 잡음 연관성을 고려한 학습기반 잡음개선 기법)

  • Kim, Sung-Deuk;Lim, Kyoung-Won
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.47 no.6
    • /
    • pp.28-38
    • /
    • 2010
  • In order to remove the noise contained in recorded analog video, it is important to recognize the real characteristics and strength of the noise. This paper presents an efficient training-based noise reduction method for recorded analog video after analyzing the noise characteristics of analog video captured in a real broadcasting system. First we show that there is non-negligible noise correlation in recorded analog video and describe the limitations of the traditional noise estimation and reduction methods based on additive white Gaussian noise (AWGN) model. In addition, we show that auto-regressive (AR) model considering noise correlation can be successfully utilized to estimate and synthesize the noise contained in the recorded analog video, and the estimated AR parameters are utilized in the training-based noise reduction scheme to reduce the video noise. Experiment results show that the proposed method can be efficiently applied for noise reduction of recorded analog video with non-negligible noise correlation.

A study on ACF Comparsion to Various Spreading Sequence for T-DMB Emergency Broadcasting (T-DMB 재난방송을 위한 다양한 확산 수열 자기상관특성 비교 연구)

  • Lee, Seung-Ho;Lee, Yong-Tae;Kim, Geon;Yang, Chung-Mo;Kim, Wan-Sik;Cho, Ju-Phil;Park, Yong-Woon;Cha, Jae-Sang
    • Journal of Satellite, Information and Communications
    • /
    • v.6 no.2
    • /
    • pp.125-130
    • /
    • 2011
  • In this paper, there was compared to the performance of the Auto Correlation Feature of each code using Spreading code for improving the data transmission technology in T-DMB disaster broadcasting. Generally, wireless mobile communication environment such as DMB occur the Inter Code Interference and the Multi-Path Interference in the process of the identification of the transmitter from the receiver. To solve this problem, spreading code technology was able to improve the security property. Also, it will be able to use in many fields of signal processing, because to control a period of the code can be variable. Therefore, in this paper, we studied to compare the performance of excellent orthogonal Golay code, Kasami code and ZCD(Zero Correlation Duration) code.

A Study of the Vehicle Tire Damage Detection using Split Spectrum Processing (스플릿 스펙트럼을 이용한 자동차 타이어 손상 검출에 관한 연구)

  • Jeon, Jae-Seok;Kim, Ho-Yeon;Kang, Dae-Soo
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.10 no.6
    • /
    • pp.113-118
    • /
    • 2010
  • The split spectrum processing algorithm of an ultrasonic wave on the tire was studied for the damage detection of a driving vehicle's tire. The processing results of normal and damaged tire was compared using the split spectrum algorithm to estimate the maximum value. The result that used Auto-correlation in case of damaged tire, the damage feature point is detected during 81ms intervals at a speed of 100km/h and during 162ms periodicity at a speed of 50km/h. This results was meaned the possibility for the tire's damage decision by damaging material with using periodicity feature point of tire damage according to vehicle speed.

The Study of Reflecting Regional Characteristics in Car Insurance for Reduction of Traffic Accidents (교통사고감소를 위한 자동차보험의 지역요인 반영에 관한 연구)

  • KIM, Dong Kuk
    • Journal of Korean Society of Transportation
    • /
    • v.33 no.3
    • /
    • pp.223-236
    • /
    • 2015
  • This study dealt with regional characteristics in car insurance for reduction of traffic accidents. The objective was to establish scientifically the verification procedure in the application of regional auto insurance rate. To specify the objective, this study conducts the correlation analysis between factors which are various in each local traffic environment and the loss ratio in automobile insurance. Also, this provides a correlation and a modal in loss ratio, classifying human factors in locality in major cause result from traffic accident. Based on the results, this brings up the problems with applying a uniform criterion for automobile insurance rate although various factors have effect on traffic accidents in locality. Therefore, what stands out most from this study is that a policy on automobile insurance applied to regional factor should be introduced.

Implementation of the Ultrasonic Local Positioning System using Dual Frequencies and Codes (이중 주파수와 코드를 이용한 초음파 위치 인식 시스템 구현)

  • Cho, Bong-Su;Cho, Seck-Bin;Yang, Sung-Oh;Baek, Kwang-Ryul;Lee, Dong-Hwal
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.14 no.7
    • /
    • pp.647-655
    • /
    • 2008
  • This paper presents real-time algorithm for an ultrasonic Local Positioning System(LPS). An ultrasonic LPS consists of 4 transmitters and n receivers. Each transmitter transmits an sequential ultrasonic signal to avoid interference of ultrasonic signal. This method is a noneffective application for a fast object. Because receiver detects four sequential transmissive ultrasonic signal and calculates a position. This paper proposes the method which 4 transmitters transmit simultaneous ultrasonic signal and each transmitter distinguished by frequencies and codes. And Auto-Correlation Function(ACF) method separates codes from an ultrasonic echo signal which is interference of each transmitter's code. If the receiver uses only ACF method, it is difficult to implement real time application for increased computation. This paper implements LPS using dual frequencies and ACF method. Using dual frequencies reduces codes length. The reduced codes length save computation in ACF. To prove this algorithm by experiment, high performance DSP(digital signal processor) used. The result shows the performance of the designed system is good enough positioning.

Automatic Extraction of Lean Tissue for Pork Grading

  • Cho, Sung-Ho;Huan, Le Ngoc;Choi, Sun;Kim, Tae-Jung;Shin, Wu-Hyun;Hwang, Heon
    • Journal of Biosystems Engineering
    • /
    • v.39 no.3
    • /
    • pp.174-183
    • /
    • 2014
  • Purpose: A robust, efficient auto-grading computer vision system for meat carcasses is in high demand by researchers all over the world. In this paper, we discuss our study, in which we developed a system to speed up line processing and provide reliable results for pork grading, comparing the results of our algorithms with visual human subjectivity measurements. Methods: We differentiated fat and lean using an entropic correlation algorithm. We also developed a self-designed robust segmentation algorithm that successfully segmented several porkcut samples; this algorithm can help to eliminate the current issues associated with autothresholding. Results: In this study, we carefully considered the key step of autoextracting lean tissue. We introduced a self-proposed scheme and implemented it in over 200 pork-cut samples. The accuracy and computation time were acceptable, showing excellent potential for use in online commercial systems. Conclusions: This paper summarizes the main results reported in recent application studies, which include modifying and smoothing the lean area of pork-cut sections of commercial fresh pork by human experts for an auto-grading process. The developed algorithms were implemented in a prototype mobile processing unit, which can be implemented at the pork processing site.

Air Quality Evaluation with Passive Samplers for Large Cities (Passive Sampler를 이용한 대도시의 대기질 평가)

  • Jeon, Eui-Chan;Kim, Shin-Do;Choi, Kum-Chan
    • Journal of Environmental Impact Assessment
    • /
    • v.7 no.2
    • /
    • pp.83-88
    • /
    • 1998
  • Filter badge type sampler has not been widely used to evaluate air quality over large cities in Korea while it can be successfully used for multi-point sampling and analysis. We evaluated the passive sampler as a new tool to monitor air quality over large cities. We latticed Metropolitan Seoul into $2{\times}2Km$ to give 136 points. $NO_2$ concentrations were measured at all the points in the Spring and Summer of 1997. According to the passive sampler data, natural green zones generally recorded lower $NO_2$ concentrations than major streets and traffic congestion areas. Passive samplers with abundant 136 points gave more detailed picture of $NO_2$ distribution while auto-monitoring network did not clearly provide the characteristics of local land use. Also, passive samplers gave 15% higher values than auto-monitoring network. The correlation between the two values appears very high judging from the regression slope of 0.92 and correlation coefficient of 0.91. This study clearly demonstrates the effectiveness of the passive sampler as a tool to monitor air quality over large cities.

  • PDF

GPS Pull-In Search Using Reverse Directional Finite Rate of Innovation (FRI)

  • Kong, Seung-Hyun;Yoo, Kyungwoo
    • Journal of Positioning, Navigation, and Timing
    • /
    • v.3 no.3
    • /
    • pp.107-116
    • /
    • 2014
  • When an incoming Global Positioning System (GPS) signal is acquired, pull-in search performs a finer search of the Doppler frequency of the incoming signal so that phase lock loop can be quickly stabilized and the receiver can produce an accurate pseudo-range measurement. However, increasing the accuracy of the Doppler frequency estimation often involves a higher computational cost for weaker GPS signals, which delays the position fix. In this paper, we show that the Doppler frequency detectable by a long coherent auto-correlation can be accurately estimated using a complex-weighted sum of consecutive short coherent auto-correlation outputs with a different Doppler frequency hypothesis, and by exploiting this we propose a noise resistant, low-cost and highly accurate Doppler frequency and phase estimation technique based on a reverse directional application of the finite rate of innovation (FRI) technique. We provide a performance and computational complexity analysis to show the feasibility of the proposed technique and compare the performance to conventional techniques using numerous Monte Carlo simulations.