• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1504-1507
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• 1997

In this paper, we investigate a traffic flow modeled by stochastic Petri nets. The model consists of two parts : the traffic flow model and signal controller model. These models are used for analyzing the flow of the traffic intersection. The results of the evaluation are derived from a Petri Net-based simulation package, Greatspn. Through simulation we compare the performances of the pretimed signal controller with those of the trafic-adaptive signal controller.

• Journal of information and communication convergence engineering
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• v.7 no.2
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• pp.170-175
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• 2009

This paper introduces Zigbee based ubiquitous service. Most of ubiquitous services require the position information. Positioning algorithms utilize the transmission characteristics of the signal. Zigbee based positioning researches have been conducted mainly for the spatial factors inside the building. This paper proposes the possibility to consider the temporal factors of Zigbee signal and analyzes empirically the signal characteristics influenced according to the temporal factors as well as the spatial factors for ubiquitous services based on Zigbee sensor network.

• 전기의세계
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• v.22 no.4
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• pp.25-29
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• 1973

The computation of transmittances between arbitrary input and output nodes is of particular interest in the signal flow graph theory imput. The signal flow matrix [T] can be defined by [X]=-[T][X] where [X] and [Y] are input nose and output node matrices, respectively. In this paper, the followings are discussed; 1) Reduction of nodes by reforming the signal flow matrix., 2) Solution of input-output relationships by means of Gauss-Jordan reduction method, 3) Extension of the above method to the matrix signal flow graph.

• Journal of the Korean Institute of Telematics and Electronics
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• v.8 no.3
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• pp.27-32
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• 1971

This paper presents the analysis of the amplitude distortion occurring in the transmission of super wideband AM signal when the amplitude and phase variations of the upper and lower sidebands of the AM signal are symmetrical, and odd symmetrical with respect to the carrier. It is shown that the case where the amplitude variations of the upper and lower sidebands of AM signal are symmetrical with respect to the carrier while the phase variations of the upper and lower sidebands are odd symmetrical with respect to the carrier induce, no amplitude distortion in AM signal transmission.

• 전기의세계
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• v.17 no.2
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• pp.11-15
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• 1968

One of the most important methods used in the modern analysis of linear networks and systems is the signal flow graph technique, first introduced by S.J. Mason in 1953. In essence, the signal-flow graph technique is a graphical method of solving a set of simultaneous. It can, therefore, be regarded as an alternative to the substitution method or the conventional matrix method. Since a flow-graph is the pictorial representation of a set of equations, it has an obvious advantage, i.e., it describes the flow of signals from one point of a system to another. Thus it provides cause-and-effect relationship between signals. And it often significantly reduces the work involved, and also yields an easy, systematic manipulation of variables of interest. Mason's formula is very powerful, but it is applicable only when the desired quantity is the transmission gain between the source node and sink node. In this paper, author summarizes the signal-flow graph technique, and stipulates three rules for conversion of an arbitrary nonsource node into a source node. Then heuses the conversion rules to obtain various quantities, i.e., networks gains, functions and parameters, through simple graphical manipulations.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.25-28
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• 2005

The optical fiber is known for the proper sensor which can accomplish the structural health monitoring, Fiber Bragg Grating sensors are being studied more than any other fiber optic sensors due to good multiplexing capabilities. But because the signal stability of FBG sensors can be influenced by the strain gradient, it needs to analyze signal of FBG sensors. Particularly acoording to strain gradient induced by structural geometry or cracks, the spectrum peak of the FBG sensor signal can be split easily. In this paper, the spectrum analysis of the FBG sensor signal was performed and the region of embedment of FBG sensors was determined in $H_2$ pressure vessel by numerical method.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1850-1851
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• 2011

The faults of a electric motor cause to rise the maintenance and repair cost and to reduce the reliability of the electric power system. In this paper, the auto fault detection system for a induction motor is developed using the torque signal spectrum analysis. The spectrum of motor torque signal is used for finding a bearing fault feature frequency. A threshold value, for detecting the motor bearing fault is set by the difference of torque signal spectrum(FFT signal) between normal condition and faulted condition of the motor.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.2
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• pp.291-296
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• 2014

Most of the statistical signal analysis processed in the time domain and the frequency domain are based on the assumption that the signal is weakly stationary(wide sense stationary). Therefore, it is necessary to know whether the surface EMG signals processed in the statistical basis satisfy the condition of weak stationarity. The purpose of this study is to analyze the accuracy of the Run-test, modified Run-test, RA(reverse arrangement)-test, and modified RA-test for assessing surface EMG signal stationarity. Six stationary and three non-stationary signals were simulated by using sine wave, AR(autoregressive) modeling, and real surface EMG. The simulated signals were tested for stationarity using nine different methods of Run-test and RA-test. The results showed that the modified Run-test method2 (mRT2) classified exactly the surface EMG signals by stationarity with 100% accuracy. This finding indicates that the mRT2 may be the best way for assessing stationarity in surface EMG signals.

• Journal of Industrial Technology
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• v.24 no.A
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• pp.67-73
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• 2004

The purpose of this study is to analyze the vibration signal of the revolution machine using the STFT(Short Time Fourier Transform). It is common to analyze the frequency of signal through FFT algorithm with the fixed sampling rate. However, in this situation the order spectrum information useful rather than the general frequency information with the fixed sampling rate. In this paper, the resampling technique was used for getting the information of order spectrum. In resampling process, the arithmetic amount and MSE(Mean Square Error) for various kinds of the signal interpolation was compared and presented the propriety of the interpolation method while developing analysis equipment. Order tracking was implemented using signal interpolation method which it has selected. Then the analyzed results were obtained through simulation using the STFT technique.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.7
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• pp.628-632
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• 2001

We propose time-frequency (TF) tools for analyzing linear time-varying (LTV) systems and nonstationary random processes. Obtained warping the narrowband Weyl symbol (WS) and spreading function (SF), the new TF tools are useful for analyzing LTV systems and random processes characterized by generalized frequency shifts, This new Weyl symbol (WS) is useful in wideband signal analysis. We also propose WS an tools for analyzing systems which produce dispersive frequency shifts on the signal. We obtain these generalized, frequency-shift covariant WS by warping conventional, narrowband WS. Using the new, generalized WS, we provide a formulation for the Weyl correspondence for linear systems with instantaneous of linear signal transformation as weighted superpositions of non-linear frequency shifts on the signal. Application examples in signal and detection demonstrate the advantages of our new results.