• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.1063-1068
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• 1989

In a two-dimensional positioning system using M-array, the crosscorrelation between the observed M-array and the reference M-array is calculated. In this case, when the distance between the object and the camera is varied, the crosscorrelation value fluctuates. This paper investigates the effect of variation of size of M-array on the crosscorrelation values.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.1
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• pp.13-19
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• 2011

Games gave the calculation method for the crosscorrelation function of a Kasami sequence and a No sequence that have been generated by the same primitive polynomial. In this paper, we calculate the crosscorrelation function of a Kasami sequence and a No sequence that have been generated by the same primitive polynomial with the periodic crosscorrelation function of two base sequences. Our method is different from the Games's method.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.10
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• pp.29-33
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• 2010

In this paper, a new family of wavelength-time codewords using modified time mapped prime sequences as a time spreading pattern is constructed. When $P_t$ = 3, we can construct $P_w^2$ wavelength-time codewords with low autocorrelation sidelobe and crosscorrelation of less than or equal to 1. When $P_t$ = 5 and $P_t$ = 7, the number of wavelength-time codewords of $P_w^2$ can be constructed with good crosscorrelation of 1 and autocorrelation of less than or equal to 2.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.221-224
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• 2001

A new code: LS code was proposed for IMT-2000 CDMA system. The code has special properties during a certain time of interval: 1) perfect autocorrelation 2) perfect crosscorrelation. The perfect autocorrelation means that the autocorrelation has nMaximum for zero time-offset and zero for other times during a certain time. Moreover the perfect crosscorrelation means that the crosscorrelation has zero during a time of interest. In the LAS-DMA system, the LS code is only used in the spreading of data bits in contrast to the conventional CDMA system. Therefore the LS code pair setting and allocation order should be dealt with carefully considering the special properties of LS code. This paper is intended as an investigation of the setting LS code pair and the sequential allocation method. Firstly, the optimum LS code pair set is proposed in order to minimize PAPR. Secondly, the sequential allocation method is studied to either minimize PAPR or expand IFW.

• Journal of Communications and Networks
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• v.5 no.1
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• pp.19-24
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• 2003

A new code, LS code, was proposed for the IMT-2000 CDMA system. The code has special properties during a specific time interval: 1) perfect autocorrelation, and 2) perfect crosscorrelation. Perfect autocorrelation means maximum autocorrelation for zero time-offset and zero autocorrelation for all other times during a specific time interval. Moreover, perfect crosscorrelation means that the crosscorrelation has zero value during a certain time, you can remove all the MAI within that time. However, the detailed properties of LS code and its exact generation method have been previously unknown. Therefore, we investigate the LS code in regards to its exact generating method, properties, and performances in this paper.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.1059-1062
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• 1989

This paper describes a new method for two-dimensional(2D) positioning system by use of crosscorrelation of vague M-arrays. An M-array pattern is attached on an object to be positioned and it is observed by a TV camera in out-of-focus condition. The crosscorrelation between the observed image data and the reference M-array gives us the information about the 2D position of the object.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.179-180
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• 1998

In this paper, we propose an algorithm to detect fetal movements using M-mode ultrasonography. To do this work automatically, we find the crosscorrelation between the current data vector of the depth direction of M-mode image and the previous one. In the crosscorrelation estimator, the variations of time lag $\tau$ at maximum crosscorrelation value means fetal movements. A woman in the 37th week of pregnancy was monitored and the ultrasonic image of fetus was recorded over 20-minute period to detect fetal movements using B-mode and M-mode ultrasonography simultaneously. And the presented method was compared with maternal perception and B-mode ultrasonography observed by clinician. The maternal perception method detected only 57% of all fetal movements observed by clinician. The detection of the presented method corresponds to the clinician's detection result.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.11
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• pp.1735-1741
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• 1993

New family of frequency hopping patterns with long period and good Hamming autocorrelation and Hamming crosscorrelation properties which can be used for frequency hopped multiple access communication systems is introduced. Period of frequency hopping patterns is qk-1, the alphabet size of frequency hopping patterns is q, and the size of family of frequency hopping patterns is q, where k is arbitrary integer and q is power of prime number. The maximum value of out-of-Phase Hamming autocorrelation function of any frequency hopping pattern and Hamming crosscorrelation function of any two frequency hopping patterns in the family is qk-1, which corresponds to optima1 Hamming correlation properties. And the average number of hits per q*q square in one frequency hopping pattern and its time shifted version or two frequency hopping patterns in the frequency hopped multiple access communication systems is less than 1.

• Review of KIISC
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• v.2 no.2
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• pp.87-92
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• 1992

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.2
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• pp.109-113
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• 2002

Van de Vusse reactor is known as a highly nonlinear chemical process and has been considered by a number of researchers as a benchmark problem for nonlinear chemical process. Various identification methods for nonlinear system are also verified by applying these methods to Van de Vusse reactor. From the point of view of identification, only the Volterra kernel of second order has been obtained until now. In this paper, the authors show that Volterra kernels of nonlinear Van de Vusse reactor of up to 3rd order are obtained by use of M-sequence correlation method. A pseudo-random M-sequence is applied to Van de Vusse reactor as an input and its output is measured. Taking the crosscorrelation function between the input and the output, we obtain up to 3rd order Volterra kernels, which is the highest order Volterra kernel obtained until now for Van de Vusse reactor. Computer simulations show that when Van de Vusse chemical process is identified by use of up to 3rd order Volterra kernels, a good agreement is observed between the calculated output and the actual output.