This paper is to present and to urge the improtance of the international standardization especially on the telecommunication fields and to present the status and necessity of the Study Activities on the CCITT Recommendations in Korea.

Digitation of telecommunication network is to introduce digital transmission and switching components into the network. Although it is proved that digitatization is economical, it is not possible to digitalize the whole network in one step, because the initial investments and resources needed would be enormous. Digitalization will have to be a stepwixe. It is therefore important that each administration makes up its own digitalization strategy as to where, when and how the various stops of digitalization have to be taken.

This study begins with investigation of the purpose and background of the International convention on Standards of Training, Sertification and Watchkeeping for seafarers 1978, London(STCW) which will be put into force on and after 28th April 1984. Author tried to confirm those common points on requirement of the qualifications between the radio officer regulated it. the STCW Convention and radio communications between the radio officer regulated in the STCW convention and radio communication operator's general certificate in the Radio Regulations annexed to the International Telecommunication convention. Then, Japanese communications administration is taken as a model for the comparative analysis, as Japan and Korea have many resembling aspects, especially legal and social aspects. Therefore, as one of urgent tasks of Korean Communications Administration preparing for the STCW convention, Istressed on partial amendment of the Korean Radio Regulatory Act.

It is the aim of the placement studies of telephone exchanges to provide facility plans which give the most economic investiment time and size to satisfy the future telephone demand of the area. Main subjects of the stuies are usually the optimal number, locations, service areas, final capacity of the telephone exchanges. This paper explains about the basic methodologies and algorithms expressed in PLAX, a software developed by KETRI to tackle the placement problem in urban areas.

In this paper, an analog optical filter link is evaluated for the transmission of baseband video signals over a single fiber. LED and PIN photo diode are used as the optical source and the detector. Frequency response of the system, DP, DG and SNR are measured.

It is described a novel SAW oscillator which can be varriable its frequenis by using two output IDT. The results show that frequencies staility is good and variable frequencies range can be broaden by design of IDT.

The exess noise factor of APD defired in different manner has been studied. And the Signal to noise ratio, error probabilities of the COK optical receiver have been presented in terms of avalanche gein.

Through intensity modulation induced by micro bending of an optical fiber, a sensor detects the pressure and frequency of acoustic wave has been implemented. Axial slots on the cylinder suface with a period of 5.5 mm induce efficient microbending of the fiber, and a rubber sleeve covering the fiber enhances the fiber. Compared with a conventional hydrophone, it has a low minimum detectable pressure and can detect acoustic wave in 100Hz - 2KHz range.

There has been a great amount of interest in the design of digital filters with low sensitivity to coefficient variations. Especiaily the wave digital filter modeled after analog IC ladder filter has been studied to have low-cocfficient-sensitivity properties. This paper examined the design of the wave digital filter and how the sensitivity and roundoff noise porperty arises. As a result of computer simulation the implementation of the digital filter was possible with a lower coefficient word length comparing with the conventional cascade structure.

It is shown that the new window function of Exponential type can be derived from Cheby-chev Identity for the design of FIR filter, and the various kinds of windows which have different characterristics can also be made by changing the coefficients of them oasily

In this paper, two - dimensional digital filtering analysis of Korean chracter image and a method which groups and sorts these filtered patterns are Presented.

The Hadamard matrix is a symmetric matrix made of plus and minus ones as entries. There fore the use of Hadamard transform in the image processing requires only the real number operations and results in the computational advantages. Recently, However, certain degradation aspects have been reported. In this paper we propose a WH matrix which retains the main properties of Hadamard matrix. The actual improvement of the image transmission in the inner part of the picture has been demonstrated by the computer simulated image developments. The orthogonal transform offers a useful facility in the digital signal processing. As the size of the transmission block increases, however, the assigment of bits for each data must increase exponentially. Thus the SNR of the image tends to decline accordingly. As an attempt to increase the SNR, we propose the WH matrix whose elements are made of $\pm$1, $\pm$2, $\pm$3, and the unitform is 8$\times$8 matrix.

90Mbps 디지털 비데오 코덱의 구성방법으로 서pel 당 비트수, sampling 주파수, 데이터 감축 방법등의 여러가지 설계 요건들이 SQNR, 하아드웨어 복잡성 정도에 따라 비교검토 되었으며 그 결과 HBL control을 포함하는 9bit PCM codec 방식이 90Mbps 전송속도에서 타당함이 밝혀졌다.

A Discrete Hilbert transformer is studied and using the Charge Transfer Device. Error problem is discussed and compared with passive, active and digital H.T circuits.

In this paper, a improved whitening filter for narrowband interference rejetion in PN spread spectrum communication systems is proposed. This whitening filter has the feedback from the output to the input of adaptive transversal filter and is superior to conventional LMS whitening filter in respect to SNR and power spectrum since the calculation of tap weight is based on maximum likelihood estimation

The performance of noncoherent fast frequency-hopped spread spectrum multiple access communication systems with square-law combining over fading channel is presented. The expression for the probalility of error as a performance measure is derived by means of momenting function of the dedecision variables, and the cross-covariance of the fading process the ambiguty function of the transmitted signals.

This paper is a study on the performance of ASK combined with Frequency-Hopping spread Spectrum techniques in the presence of interfering channel with uniformly distribyted frequency.

A Study is presented showing the effect of carrier phase error on the error-rate of a PR shaped SQAM digital radio system. A simple upper bound on the probability of error as a function of phase error is derived and compared to one another. The result is that if carrier phase error is less than 3 there is no serious degradation.

본 논문은 광대역에서 임의로 발생하는 TONE BURST 파형의 패턴을 여러파라미터로 분석하여 이를 잡음과 섞여있는 경우에 적용하였다. 그결과 특정의 REFERENCE 신호가 없는 경우에는 AUTOCORRELATION 향수가 TONEBURST파형분석에 최적 파라미터 임을 입증한다.

This paper presents a new method for the optimum capacity assignment in store-and-forward communication networks under a total fixed-capacity constraints. Any two link capacities needed in this method can have the desirable quantites and then other capacities can be obtained from the fixed two link capacities. When the minimum and the maximum capacities that are the quantites of the conventional method are fixed, the total average time delay from the new method is almost the same as that from the conventional method. And when the minimum capacity is fixed, the new method gives smaller average time delay.

In this paper, a functional m-redundant system, which is me-fault tolerant, is defined based on the graph-theory. This system is designed to be t fault-diagnosable by comparing its unit's outcomes without additive test functions, and so, the system down for diagnosis is not needed. the diagnostic model for this system is presented and this effectively uses system's redundancy. It is shown that this model can be converted into Preparata's model. Thus, the diagnostic characteristics of a functional m-redundant system is analyzed by the methods originated by Preparata et al..

A minicomputer system with the purpose of automations the operations of a Repair Service Bureau is described. SLMOS automates three major functional areas-administration, testing, and report senerations In the administration of repair sevice SLMOS performs a database maintenance functions alons with trouble collection and tracking. Trough ALT, automated testing of customer lines is performed, and the results of the test are utilized to dertermine the action taken to effect a repair. Certain problem areas may be detected and corrected by using the reports senerated by Trouble Report statics and Analysis System.

This paper presents automated system for trunk test in a telephone network. Test results anlysis were executed by the controller using a microprocessor. Transmission measurements for loss, error are made by the automated measuring enipment.