• Title, Summary, Keyword: Random signal

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A Study on Adaptive Random Signal-Based Learning Employing Genetic Algorithms and Simulated Annealing (유전 알고리즘과 시뮬레이티드 어닐링이 적용된 적응 랜덤 신호 기반 학습에 관한 연구)

  • Han, Chang-Wook;Park, Jung-Il
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.10
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    • pp.819-826
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    • 2001
  • Genetic algorithms are becoming more popular because of their relative simplicity and robustness. Genetic algorithms are global search techniques for nonlinear optimization. However, traditional genetic algorithms, though robust, are generally not the most successful optimization algorithm on any particular domain because they are poor at hill-climbing, whereas simulated annealing has the ability of probabilistic hill-climbing. Therefore, hybridizing a genetic algorithm with other algorithms can produce better performance than using the genetic algorithm or other algorithms independently. In this paper, we propose an efficient hybrid optimization algorithm named the adaptive random signal-based learning. Random signal-based learning is similar to the reinforcement learning of neural networks. This paper describes the application of genetic algorithms and simulated annealing to a random signal-based learning in order to generate the parameters and reinforcement signal of the random signal-based learning, respectively. The validity of the proposed algorithm is confirmed by applying it to two different examples.

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Development of a Modified Random Signal-based Learning using Simulated Annealing

  • Han, Chang-Wook;Lee, Yeunghak
    • Journal of Multimedia Information System
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    • v.2 no.1
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    • pp.179-186
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    • 2015
  • This paper describes the application of a simulated annealing to a random signal-based learning. The simulated annealing is used to generate the reinforcement signal which is used in the random signal-based learning. Random signal-based learning is similar to the reinforcement learning of neural network. It is poor at hill-climbing, whereas simulated annealing has an ability of probabilistic hill-climbing. Therefore, hybridizing a random signal-based learning with the simulated annealing can produce better performance than before. The validity of the proposed algorithm is confirmed by applying it to two different examples. One is finding the minimum of the nonlinear function. And the other is the optimization of fuzzy control rules using inverted pendulum.

Extended Early-Late Phase Scheme using Combined Pseudo-Random Noise Signal to Detect GPS Repeat-Back Jamming Signals (GPS 재방송 재밍신호 검출을 위한 통합 의사잡음신호를 사용한 확장된 ELP 기법)

  • Yoo, Seungsoo;Yeom, Dong-Jin;Jee, Gyu-In;Kim, Sun Yong
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.6
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    • pp.483-489
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    • 2016
  • This paper proposes a repeat-back jamming signal detection scheme that utilizes a combined pseudo random noise signal that is effective for processing a global positioning system (GPS) repeat-back jamming signal with the early minus late phase scheme to alleviate any existing multipath signal detection. The proposed scheme uses the combined pseudo random noise signal to treat repeat-back jamming signals like similar multipath signals and can effectively detect a repeat-back jamming signal by applying the early minus late phase scheme to a combined pseudo random noise signal. Through a Monte-Carlo simulation, the detection probability of the proposed scheme is better than the one of the conventional scheme under low jamming to signal power ratio.

Comparison of Random and Blocked Practice during Performance of the Stop Signal Task

  • Kwon, Jung-Won;Nam, Seok-Hyun;Kim, Chung-Sun
    • The Journal of Korean Physical Therapy
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    • v.23 no.3
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    • pp.65-70
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    • 2011
  • Purpose: We investigated the changes in the stop-signal reaction time (SSRT) and the no-signal reaction time (NSRT) following motor sequential learning in the stop-signal task (SST). This study also determined which of the reduction0s of spatial processing time was better between blocked- and random-SST. Methods: Thirty right-handed healthy subjects without a history of neurological dysfunction were recruited. In all subjects, both the SSRT and the NSRT were measured for the SST. Tasks were classified into two categories based on the stop-signal patterns, the blocked-SST practice group and random-SST practice group. All subjects gave written informed consent. Results: In the blocked-SST group, both the SSRT and the NSRT was significantly decreased (p<0.05) but not significantly changed in the random-SST group. In the SSRT and the NSRT, the blocked-SST group was faster than the random-SST group (p<0.05). In the post-test SST after practice of each group, the SSRT was significantly decreased in the random-SST group (p<0.05), but the NSRT showed no significant changes in either group. Conclusion: These findings demonstrate that random-SST practice resulted in a decrease in internal processing times needed for a rapid stop to visual signals, indicating motor skill learning is acquired through improved response selection and inhibition.

Weak Random Signal Detection:In Signal-Dependent Noise (약한 확률적 신호 검파 : 신호의 존성 잡음이 있는 경우)

  • 송익호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.13 no.4
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    • pp.332-339
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    • 1988
  • Using a generalized observation model, in which one can express the effects of non-additive noise such as signal-dependent noise and multiplicative noise in addition to purely-additive noise, the problem of weak random-signal detection is investigated. It is shown that the test statistics of locally optimum detectors for detection of weak random signals in signal-dependent noise model are interesting extensions of those in purely-additive noise model. This result is a complement to the result for weak random-signal detction in multiplicative noise model.

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PROPERTIES OF RANDOM SIGNALS IN WAVELET DOMAIN

  • Lee, Young Seock;Kim, Sung Hwan
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.3 no.1
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    • pp.107-114
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    • 1999
  • In many applications (e,g., identification of non-destructive testing signal and biomedical signal and multiscale analysis of image), it is of interest to analyze and identify phenomena occurring at the different scales. The recently introduced wave let transforms provide a time-scale decomposition of signals that offers the possibility of such signals. However, there is no corresponding statistical properties to development of multiscale statistical signal processing. In this paper, we derive such properties of random signals in wavelet domain.

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A Simple Random Signal Generator Employing Current Mode Switched Capacitor Circuit

  • Yamakawa, Takeshi;Suetake, Noriaki;Miki, Tsutomu;Uchino, Eiji;Eguchi, Akihiro
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • pp.865-868
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    • 1993
  • This paper describes a simple random signal generator employing by CMOS analog technology in current mode. The system is a nonlinear dynamical system described by a difference equation, such as x(t+1) = f(x(t)) , t = 0,1,2, ... , where f($.$) is a nonlinear function of x(f). The tent map is used as a nonlinear function to produce the random signals with the uniform distribution. The prototype is implemented by using transistor array devices fabricated in a mass product line. It can be easily realized on a chip. Uniform randomness of the signal is examined by the serial correlation test and the $\chi$2 test.

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THE EFFECT OF MASKED SIGNAL ON THE PERFORMANCE OF GNSS CODE TRACKING SYSTEM

  • Chang, Chung-Liang;Juang, Jyh-Ching
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.2
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    • pp.223-228
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    • 2006
  • The main purpose of this paper is to describe the code tracking performance of a non-coherent digital delay lock loop (DLL) or coherent DLL while tracking GNSS signal in the presence of signal masking. The masking effect is usually caused by buildings that obscure the signal in either a periodic or random manner. In some cases, ideal masking is used to remove random or periodic interference. Three types of the masked signal are considered - no masking, periodic masking, and random masking of the signal input to the receiver. The mean time to lose lock (MTLL) of the code tracking loop are evaluated, and some numerical result and simulation results are reported. Finally, the steadystate tracking errors on the performance of the tracking loop in interference environment are also presented.

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Design and Implementation of True Random Noise Radar System

  • Min, Woo-Ki;Kim, Cheol-Hoo;Lukin, Constantin A.;Kim, Jeong-Phill
    • Journal of electromagnetic engineering and science
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    • v.9 no.3
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    • pp.130-140
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    • 2009
  • The design theory and experimental results of a true random noise radar system are presented in this paper. Target range information can be extracted precisely by correlation processing between the delayed reference and the signal received from a target, and the velocity information by the Doppler processing with successive correlation data. A K-band noise radar system was designed using random FM noise signal, and the characteristics of the fabricated system were examined with laboratory and outdoor experiments. A C-band random FM noise signal was generated by applying a low-frequency white Gaussian noise source to VCO(Voltage Controlled Oscillator), and a K-band Tx noise signal with 100 MHz bandwidth was obtained by using a following frequency multiplier. Two modified wave-guide horn arrays were designed and fabricated, and used for the Tx and Rx antennas. The required amount of Tx/Rx isolation was attained by using a coupling cancellation circuit as well as keeping them apart with predetermined spacing. A double down-conversion scheme was used in the Rx and reference channels, respectively, for easy post processing such as correlation and Doppler processing. The implemented noise radar performance was examined with a moving bicycle and a very high-speed target with a velocity of 150 m/s. The results extracted by the Matlab simulation using the logging data were found to be in a reasonable agreement with the expected results.

A Study on the Implemanation of IF Stage for Reducing Random Noise in the Mobile Communications (이동통신에 적용한 랜덤 잡음 제거를 위한 IF stage 구현에 관한 연구)

  • 이은기;박영철;차균현
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.17 no.6
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    • pp.572-579
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    • 1992
  • In this thesis, feedback circuit and FM detector applied to superheterodyne receiver to extract audio signal without random noise Is implemented. The feedback loop circuit converts 45MHz received signal to 4SiKHz If signal containing mess-age without random noise. Also the feedback loop provides the End local frequency, so narrowband BPF which is containing maximum Doppler frequency without message Is needed. Finally, quadrature FM detector extract audio signal by synthesis o350" shifted signal and ampli-tude limited signal. RSSI characteristics is measured and audio characteristics Is compared with existing If module.

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