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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
The Journal of Korean Institute of Communications and Information Sciences
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Journal DOI :
The Korean Institute of Communications and Information Sciences
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Volume & Issues
Volume 9, Issue 4 - Dec 1984
Volume 9, Issue 3 - Oct 1984
Volume 9, Issue 2 - Jul 1984
Volume 9, Issue 1 - Apr 1984
Selecting the target year
A Study on the Public Radio Communications between Seoul and the Ship on the North Pacific Ocean
The Journal of Korean Institute of Communications and Information Sciences, volume 9, issue 4, 1984, Pages 141~152
Nowadaty, To keep pace with the mass transportation carried out by vessels in the international trade, the Korean government is trying to make a rapid progress to be a higher ranked shipping country to the world through the shipping increase. For the effective management of international trade by vessels and the safe operation of vessels, it is indispensable for ships radio communication to be effective and smooth. Therefore, to enhance the efficiency of ships radio communication is one of the primary factors to be solved for the econimics of shipping management. The reserch area is not only limited to the ships radio communication on the North Pacific Ocean but limited to the ships radio communication which is one of the chiefest methods of communications. From the research for the efficient methods of ships radio communication, the following results are obtained. (1) The operator on ships radio communication should have the knowledge of specific know-how and wide experience in the operation of ships radio communications. (2) The operator should abopt the radio propagation prediction made by the Ministry of Communications to use the best ionosphere reflection in the short wave communications. (3) The increase the radio officer of 1 to 2 in order to contrive the safety at sea and to keep the ships radio communication fare low. (4) The owner should pay their attentions to the education and employment of radio officer. (5) The authorities concerned on the ships radio communication should estabilish the effective and consistent policy for the ships radio officers.
A Simple Local Area Network Controller by Non-Persistent CSMA
The Journal of Korean Institute of Communications and Information Sciences, volume 9, issue 4, 1984, Pages 153~156
A local area network(LAN) controller is designed according to non-persistent CSMA protocols. By meas of a buffer register, a microcomputer interfaces with the LAN controller. To keep bus utilization near the optimal efficiencies, the transmission intervals are adjusted as a function of
. A message in the form of a packet consisting of 128bytes is transitted to the bus. The maximum transmission rate of 19.2Kbps is obtained at layer 1.
Performances of Digital Amplitude-Frequency Modulation System
The Journal of Korean Institute of Communications and Information Sciences, volume 9, issue 4, 1984, Pages 157~162
The data transmission in radio channel is mainly influenced by interfere and random noise. The increasing man-made impulsive noise environment has the necessity to consider impulsive noise than conventional white gaussian noise in digital communications. In this paper, we have investigated the error rate performance of hybrid modulation system. AFSK, which is composed of ASK and FSK in the environment of electromaganetic interference (EMI), especially impulsive noise.
A Study on the Recursive Parameter Estimation Density Function Algorithm of the Probability
The Journal of Korean Institute of Communications and Information Sciences, volume 9, issue 4, 1984, Pages 163~169
We propose a new parameter estimation algorithm that converges with probability one and in mean square, if the mean is the function of parameter of the probability density function. This recursive algorithm is applicable also even though the parameters we estimate are multiparameter case. And the results are shown by the computer simulation.
The 12 Channel TDM/FDM Translator with Polyphase Network and Fast DCT
The Journal of Korean Institute of Communications and Information Sciences, volume 9, issue 4, 1984, Pages 170~178
For the reduction of the 12-channel TDM/FDM translation time the 14-point fast DCT algorithm is used and the polyphase network which translates the prototype filter into the channel filters required in each channel is designed. For the prototype filter the degree of the numerator is 168 and the coefficients have symmetry values, the degree of the numerator is 6. Such a prototype filter is consistant with the CCITT requirements. In this case the required multiplication rate is CCITT requirements. In this case the required multiplication rate is
multiplications/sec. channel and reduces to about 15-40% of the rate required in the exising systems. The proposed 12-channel TDM/FDM translation system is simulated using a demodulation system with a computer (PRIME 750) and the results show that the proposed conversion method is valid.
A Study on the Optical Character Recognition using Optical Correlators Computer
The Journal of Korean Institute of Communications and Information Sciences, volume 9, issue 4, 1984, Pages 179~183
N reference patterns called principal components are sufficient to identify one out of N characters, calculated by computer and fablicated. An incogerent optical correlator is used for correlation coefficient measurements and it is shown that that this method has better discrimination ability that analog measuments using matched filter.