A Tx modulator of the AMPS cellular wireless communication has been implemented using the PLL synthesizer, of which is modified for multiple frequency output capability. The frequency range is in 825-845 MHz with the 666 channels of 30KHz channel spacing and its switching time is less than 40 msec. The purpose of this paper is to develope the PLL frequency synthesizer with the high speed pulse swallow prescaler in order to save power consumption and cost. The PLL frequency synthesizer is studied in this paper to apply the cellular communication modulator.

A forward error correction (FEC) technique is presented for speech data in 16 Kbps digital mobile communications. 14Kbps SBC-APCM(AQB) and QPSK are used as speech coding and modulation techniques, respectively. Because each bit in a speech data block had different importance, applying FEC to speech data bit-selectively in more effective than applying FEC to all speech data equally. To select bits in a speech data block to be protected by FEC the bit error sensitivity of each bit is computed. For a few BCH and Reed-Solomon codes used as bit-selective FEC the performance of the coding technique is computed.

We proposed a new radiating structure generating a circularly polarized wave. Futhermore, we show that it is possible to generate all kind of polarizations by simple variations of some schematic factors. Basically, the structure composed of a slot and a strip. The length of slot and strip, the slot-strip distance and the strip inclination are the crucial factors to determine the polarization form. In this paper, we investigated the effects on polarization and other radiation characteristics by varying the factors.

The noise currents in the load of cascaded transmission lines excited by a nearly small loop are analyzed and the effective approxiamte method by which we can calculate these currents easily and the computation time can be significantly reduced is developed. Numerical results for n=3 are well agreed with those of Smith by the maximum difference of 3-4dB and show that the length of a segment of line regarded to be illuminated by uniform electric fields should be 1.3 times the distance from the loop to the point midway between the conductors.

A numerical method is presented for determining the static charge distribution and the capacitance of a round disk capacitor. In the employed numerical scheme annular patch subdomains are introduced to reduce the matrix size and to mprove the accuracy of the numerical calculations. The method of moments is utilized to calculate the charge distribution, and the capacitance and equipotential lines are also found from the numerically computed charge distributions. To show the validity of the results the proposed method is applied to the round disk and the dielectric filled capacitor.

This paper presents a recognition method which interprets 3-D object in terms of several silhouettes of quadtree and octree. Object representation used in object matching should be invariant with respect to locatin and orientation of the object. Generalized octree is projected on to image plane along the principal axes. Regular octree is made from orthogonal directions, but generalized octree is independent to viewing directions. Recognition process is achieved in two-stage matching. The quadtrees and octrees of unknown object with minimum dissimilarities are matched with the quadtrees and octrees of the models. So as to verify efficiency of 3-D object representation and accuracy of object recognition, experiments are performed for 14 different type of geometrical models and its results have been shown.

A method of recognizing objects is proposed that uses a concept of modified incremental circle transform. The modified incremental circle transform, which maps bundaries of an object into an unit circle, represnets efficiently the shape of the boundaries detected in digitized binary images of the objects. It is proved that modified incremental circle transform of object, which is invariant under object translation, rotation, and size, can be used as feature information for recognizing two dimensional polygonal object efficiently.

The control method which electrically subdivides 1 step(1.8\ulcornerstep) of a PM step motor into 64 micro-step (0.028\ulcornerstep) is realized using micro-step algorithm on the basis of the look up table method and the position and velocity control using Z-80 microprocessor is also realized. With micro-stepping. The resolution of the system is improved, also by micro-step control of driving-current of the step motro, which is followed by the increase of micro-step subdivision-coefficient, the precise position and velocity control of step-motor can be realized and the stabilization of the system is improved.

The geometrical algorithm for generating a 3-phase SPWM signal for VVVF (Variable Voltage, Variable Frequency) inverter drives is proposed. In this techniques, it is suitable for micro-processor based implementation since the pulsewiths are computable in real time from simple analytic expressions. System hardware consists of the inverter circuit and the 3-phase SPWM signal generating circuit. The inverter circuit is a 3-phase SPWM signal generating circuit is single board micro-processor consisting of Z-80A CPU, EPROMXI, CTC, PIO. The method of controlling VVVF at the inverter output is discussed here.

Sinterbility, microstructure, mechenical and electrical properties of yttriastabilized zirkconiz (92 mole % ZrO2 + 8 mole % Y2O3) doped with 0.5 mole % SiO2 and 0-2.O mole% Al2O3 were studied as a functin of Al2O3 addition. Sintered density increased with increasing Al2O3 addition up to o.5 mole%but decreased up to 1.0mole% Al2O3. Vickers hardness is proportional to sintered density. The specimen added 0.5mole% Al2O3 and 0.5mole% SiO2 exhibited a maximum conductivity. And the specimen added 0.5 mole % Al2O3 and 0.5 mole% SiO2 was measured a maximum electromotive force for a characteristics of oxyzen partial pressure.

With the MOS device scailing down, the substrate concentration must increase in order to avoid punchthrough leakage current due to the DIBL(Drain Induced Barrier Lowering) effect. However the enhancement of the substrate concentration increases source, drain juntion capacitances and substrate current due to hot elelctron, degrading the speed characteristics and reliability of the MOS devices. In this paper, a new device, called CODE(Channel Only Dopant Enhancement) MOS, an its fabrication are proposed. By comparing the fabricated CODE MOSFET with the conventional device, the improvements on DIBL, substrate current and source, drain juntion capacitances are realized.

With a wide spread of 32 bit personal computers, a simple structure and high performance memory system have been highly required. In this paper, a memory block is constructed by using a modified hierarchical bit line in which the DRAM bit line and the latch which works as a SRAM cell are integrated by an interface gate. And the new architecture memory DSRAM(Dynamic Static RAM) is proposed by interleaving the 16 memory block. Because the DSRAM works with 16 page, the page is miss ratio becomes small and the RAS precharge time which is incurred by page miss is shortened. So the DSRAM can implement an optimum page interleaving and it has good compatibility to the existing DRAMs. The DSRAM can be widely used in small computers as well as a high performance memory system.

This paper presents a method of constructing an Arithmetic Operation Unit Systems (A.O.U.S.) over Galois Field GF(2**m) for the purpose of the four arithmetical operation(addition, subtraction, multiplication and division between two elements in GF(2**mm). The proposed A.O.U.S. is constructed by following procedure. First of all, we obtained each four arithmetical operation algorithms for performing the four arithmetical operations using by mathematical properties over GF(2**m). Next, for the purpose of realizing the four arithmetical unit module (adder module, subtracter module, multiplier module and divider module), we constructed basic cells using the four arithmetical operation algorithms. Then, we realized the four Arithmetical Operation Unit Modules(A.O.U.M.) using basic cells and we constructd distributor modules for the purpose of merging A.O.U.M. with distributor modules. Finally, we constructed the A.O.U.S. over GF(2**m) by synthesizing A.O.U.M. with distributor modules. We prospect that we are able to construct an Arithmetic & Logical Operation Unit Systems (A.L.O.U.S.) if we will merge the proposed A.O.U.S. in this paper with Logical Operation Unit Systems (L.O.U.S.).

A multivariable equalizer is designed which compensates transmission distortion for coaxial transmission line. The characteristic transfer function with bilateral parameter domain is approximated using the expansion method of orthonormal function and Gram Schmidt orthogonal function, but the parameter domain of approximated function is limited to unilateral. To solve that problem, Bode type transfer function is used to give bilateral variable characteristic to approximated function. The multivariable equalizer in this paper can be substituted for the current equalizer which consist of a fixed equalizer and a variable equalizer.

This paper describes the method of the Korean character recognition by means of feature points extraction. Also, the preprocessing neural chip for noise elimination, smoothing, thinning and feature point extraction has been designs. The subpatterns were separated by means of advanced index algorithm using mask, and recognized by means of feature points classification. The separation of the Korean character subpatterns was abtained about 97%, and the recognition of the Korean characters was abtained about 95%. The preprocessing neural chip was simulated on SPICE and layouted by double CMOS 2\ulcorner design rule.

In this paper, a subband coding scheme using the human visual system(HVS) model for encoding monochrome images is proposed to produce perceptually higher quality images compared with the regular subband coding scheme. The proposed approach first transforms the intensity image to the density image by a point nonlinear transformation. A frequency band dexomposition of the density image is carried out by means of 2-D seaprable quadrature mirror filters, which split the density image spectrum into 16 equall rate subbands. Bits are allocated among the subbands to minimize the weighted mean squar error (WMSE) for differential pulse code modulation(DPCM) coding of the subbands. The weight for each subband is calculated from the modulation transfer function (MTF) of the HVS model at corresponding frequencies. The performances of the proposed approach are evaluated for 256 * 256 monochrome images at the bit rates of 0.5, 0.75 and 1.0 bita per pixel. Computer simulation results indicate that using the HVS model yields more pleasing reconstructed images than regular subband coding approach which does not use HVS model.

This paper describes design and implementation of a real-time high-precision vision system for an automation of SMT(surface mounting technology ). Also, a part inspection algorithm which calculates the position and direction of SMD(surface mounted device) accurately and performs the ruling using those information are presented, and a parallel processing technique for implementing those algorithms is also described. For a real-time implementation of iage acquisition and processing, several hardware modules, namely, multi-functional A/D-D/A board, frame memory board are developed. Particularly, a PE (processing element) board which employs the DSP56001 DSP (digital signal processor) is developed for the purpose of concurrent processing of part inspection algorithms. A stand-alone vision system is built by integration of the developed hardware modules and related softwares.

Experties of recognizing an object despite of every possible occlusions among objects is difficult to be provided directly to a system. In this paper, we propose a method for inferring inherent shape-characteirstics of an object from training views provided. The method learns rules incrementally by alternating the rule induction process from limited number of training views and the rule verification process from the following taining views. The learned rules are represented using logical expressions to enhance the readability. Thr proposed method is tested by simulating occlusions on 2-dimensional objects to examine the learning process and to show improvement of recognition rate. Thr result shows that it can be applied to a practical system for 3-dimensional object recognition.

This paper proposes a memory intensive VLSI architecture for the realization of real-time 3x3 neighborhood processor based on the distributed arithmetic. The proposed architecture is characterized by a bit serial and multi-kernel parallel processing which exploits the pixel kernel parallelism and concurrency. The chip implements 8 neighborhood processing elements in parallel with efficirnt input and output modules which operate concurrently. Besides the a4chitectural design of a neighborhood processor, the design methodology using module generator concept has been considered and MOGOT(MOdule Generator Oriented VLSI design Tool) has been constructed based on the workstation. Based on these design environments MOGOT, it has been shown that the main part of the suggested architecture can be designed efficiently using 2\ulcorner double metal CMOS technology. It includes design of input delay and data conversion module, look-up table for inner product operation, carry save accumulator, output data converter and delay module, and control module.

Many researchers have been interested in whether complex computational problems can be solved by the neural net or not. Especially, problems of early vision are integrated by Tikhonov's regularization theory. Regularization technique can be realized in resistive net. In this paper, we suggest the resistive net with upper and lower thresholder to be able to compute shape from shading and to solve its discontinuous problem. We simulate three algorithms-Horn's algorithm, resistive net and up-low thrwsholding net -with respect to three cases-fully boundary, boundary losing partly and noisy image. As being able to cope with crease and discontinuous parts, we get the good 3D shape from shading.