Journal of Electrical Engineering and information Science
The Korean Institute of Electrical Engineers
- Bimonthly
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- 1226-1262(pISSN)
Volume 2 Issue 4
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A multiprocessor microprocessor named SMPC(scaleable multiprocessor chip) that contains tow IU (integer unit) is presented in this paper. It can execute multiple instructions from several tasks exploiting task-level parallelism that is free from instruction dependencies, and provide high performance and throughput on both single program and multiprogramming environments. the IU is a 32-bit scalar processor expecially designed to boost up the performance of string manipulations which are frequently used in RDBMS(relational data base management system) applications. A memory management unit and a data cache shared by two IUs improve the performance and reduce the chip area required. ETH SMPC is implemented in VLSI circuit by custom design and automated design tools.
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This paper describes a scalable systolic synchronous memory for digital signal processing and packet switching. The systolic synchronous memory consists of the 2-D array of small memory blocks which are fully pipelined and communicated in three directions with adjacent blocks. The maximum delay of a small memory block becomes the operation speed of the chip. The array configuration is scalable for the entire memory size requested by an application. it has the initial latency of N+3 cycles with NxN array configuration. We designed an experimental 200 MHz 4Kb static RAM chip with the 4x4 array configuration of 256 SRAM blocks. It was fabricated is 0.8
$\mu\textrm{m}$ twin-well single-poly double-metal CMOS technology. -
A design methodology of the analog current-mode and width programmable integrator for a low voltage (3V) and low power application is developed and the integrator designed by this method is successfully fabricated by the 0.8
$\mu\textrm{m}$ CMOS n-well single poly/double metal standard digital process. The integrator occupies the active chip area of 0.3$\textrm{mm}^2$ . The experimental result illustrates a low power dissipation (1.0mW∼3.55 mW), 65dB of the dynamic range, and digitally and width programmability (10MHz∼30MHz) with an external digital 4 bit. -
In this paper, we propose a new communciation scheme combining both MT modulation and DS-CDMA with a concatenated orthogonal/PN spreading sequence. This scheme incorporates the advantages of both DS-CDMA wit a concatenated sequence, and an MT modulation technique to combat the effect of a multipath fading channel. It is shown that he proposed system outperforms the MT-CDMA system with a convetional PN sequence.
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Presented are closed-form expressions of the three-state exponentially correlated acceleration (ECA) target-tracking filter. The steady-state solution is derived based on Vaughan's approach for the case that he measurements of target position and velocity are available at discrete point in time. The solution for ECA tracking filter using only position measurements and the solution for the constant acceleration (CA) tracking filter are obtained as a special case of the presented results.
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In this paper, robust stability analysis for the fuzzy feedback linearization regulator is presented. Well-known Takagi-Sugeno fuzzy model is used as the MISO nonlinear plant model. Uncertainty and disturbance are assumed to be included in the model structure with known bounds. For these structured uncertainty and disturbances, robust stability of the close system is analyzed in both input-output sense and Lyapunov sense. The robust stability conditions are proposed by using multivariable circle criterion and the relationship between input-output stability and Lyapunov stability. The proposed stability analysis is illustrated by a simple example.
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With rapid increase of information requirements from various application areas, there has been much research on dynamic information storage structures that effectively support insertions, deletions and updates. In this appear we evaluate the performance of he existing dynamic signature file methods such as the S-tree, Quick Filter and HS file and provide guidelines for the most effective usage to a given operational environment. We derive analytic performance evaluation models of the storage structures based on retrieval time, storage overhead and insertion time. We also perform extensive experiments with various data distributions such as uniform, normal and exponential distributions. The relationships among various performance parameters are throughly investigated. We show through performance comparison based on analytic models and experiments that regardless of data distribution, the HS file significantly improves performance in both the retreival time and the storage overhead over S-tree and Quick Filter.
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In this paper th use of compensation based on a combination of active plus reactive power at distribution model system is proposed. The basic voltage-power relationships for the linearized case on an infinite bus are used and the compensation angle is defined based on the voltage magnitude response to small power injection. Compensation is supplied at several locations, and the system is subjected to varying fault scenarios, with its response observed under different system conditions. As number of control issues for a storage-based active/reactive power compensator as a bus voltage regulator are explored to compare the effectiveness of active/reactive again reactive-only compensation.
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In this paper, the power system stabilizer(PSS) using the sliding mode observer-model following(SMO-MF) with closed-loop feedback (CLF) for single machine system is extended to multimachine system. This a multimachine SMO-MF PSS for unmeasureable plant state variable is obtained by combining the sliding mode-model following(SM-MF) including closed-loop feedback(CLF) with the full-order observer(FOO). And the estimated control input for unmeasurable plant sate variables is derived by Lyapunov's second method to determine a control input that keeps the system stable. Time domain simulation results for the torque angle and for the angular velocity show that the proposed multimachine SMO-MF PSS including CLF for unmeasurable plant sate variables is able to damp out the low frequency oscillation and to achieve asymptotic tracking error between the reference model state at different initial conditions and at step input.
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In this paper, a general fuzzy syntactic method for recognition of flaw patterns and for the measurement of flaw characteristic parameters for a non-destructive inspections signal, called eddy-current, is presented. Solutions are given to the subtasks of primitive pattern selection, signal to symbol transformation, pattern grammar formulation, and event-synchronous flaw pattern extraction based on the grammars. Fuzzy attribute grammars are used as the model for the pattern grammar because of their descriptive power in the face of uncertain constraints caused by nose or distortion in the signal waveform, due to their ability to handle syntactic as well as semantic information. This approach has been implemented and the performance of eh resultant system has been evaluated using a library of law patterns obtained from steam generator tubes in nuclear power plants by an eddy current-based non-destructive inspection method.
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The dielectrophoretic(DEP) force acting on a cell in an electric field is experimentally determined. A cell is accelerated by the DEP force in an electric field generated between micro planar electrodes. the position of the cell is measured and the velocity and acceleration of the cell are calculated based on the measured position data. The DE force is determined from the motion equation of a moving cell in suspension. The electrode structure is fabricated by micromachining technology and the height of electrodes is 1
$\mu\textrm{m}$ . Radish cell and yeast are used in th experiments. In the case of radish cell, the DEP force increases as voltage or frequency(1MHz∼3MHz) increases. The voltage dependence can be explained that the DEP force increases when ▽│E│$^2$ increases. The frequency dependence means that Re[x\ulcorner] of radish cell is maximized in a certain frequency. In the case of yeast, the DEP force increases only as voltage increases. The reason for the voltage dependence is the same with the case of radish. The DEP force increases only as voltage increases. The reason for the voltage dependence is the same with the case of radish. The DEP force on a yeast does not vary when the frequency varies from 1MHz to 3MHz. This result coincides with the fact that the value of calculated Re[x\ulcorner] is constant in the test frequency range. -
A free space transmission method using standard gain horn antennas in the frequency range from 9.0 to 10.5GHz is applied to determine the dielectric properties of grain such as rough rice ,brown rice and barley. The dielectric constant and loss factor, which depend on the moisture content of the wetted grain are obtained from the measured attenuation and phase shift by vector network analyzer. The moisture content of grain varied from 11 to 25% based on this wetted condition. The measured values of dielectric constants as a function of moisture density are compared with values of those obtained using he predicted model for estimating dielectric constants of grain. The effect of density fluctuation, high is an important parameter governing the dielectric properties of grain, on the dielectric constant and loss factor is presented. A new density-independent model in terms of measured attenuation an moisture density is proposed of reducing the effects of density fluctuation on the moisture content measurement.
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A unified, modular and decoupled approach for the simulation of converter fed induction machine systems is presented. The system under consideration could have semiconductor devices connected to the stator or the rotor of the induction machine for the purpose of controlling its performance. The machine model, however is invariant to these aspects. The model spans the circuit and equation domains of description thus allowing he advantages of both these domains of descriptions to be utilized. The results obtained using this machine and switch model for a VSI fed induction machine (stator fed, rotor shorted0 are compared with those from laboratory experiment to establish the validity and accuracy of th approach. Results for a slip energy recovery system are also presented and compared with those of earlier workers to establish the performance of the models and algorithms in he doubly-fed mode of operation of induction machine systems.
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A method of detecting the three phase currents for a voltage-fed pusle width modulated(PWM) inverter is proposed, where only one current sensor is utilized on the dc-link. The proposed method has the constant sampling time by employing he modified space-vector PWM technique which generates the rearranged switching pattern to detect a phase current from ad dc-link current. Experimental results show that eh proposed scheme provides a very good detection method of three phase currents without phase current sensors. This method is very simple and has small detection errors.
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This paper presents a new approach to obtaining a reduced-order model for multi-module converters. The proposed approach can be used to derive the reduced-order model for a wide class of multi-module converters including pulse-width-modulated (PWM) converters, soft-switched PWM converters, and resonant converters. The reduced-order model has the structure of a conventional single-module converter while preserving the dynamics of the original multi-module converter. Derivation procedures and the use of the reduced-order model is demonstrated using a three-module boost converter.
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The new classified model for N-p heterojunction diode is derived and used extensively in analyzing the current-voltage(I-V) characteristics of the HBTs. A new classification method is presented in order to simplify I-V equations and easily applied to the modeling of HBTs. This classification method is characterized by the properties of devices such as high level injection, the thickness of one or both bulk regions, the surface recombination and the generation-recombination. The simulation results using the proposed model agree well with the experimentally observed I-V behaviors and show good efficiencies in its application to HBTs with respect to mathematical formulation.
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A new SOI NMOSFET with a 'LOCOS-like' shape self-aligned polysilicon gate formed on the recessed channel region has been fabricated by a mix-and-match technology. For the first time, a new scheme for implementing self-alignment in both source/drain and gate structure in recessed channel device fabrication was tried. Symmetric source/drain doping profile was obtained and highly symmetric electrical characteristics were observed. Drain current measured from 0.3
${\mu}{\textrm}{m}$ SOI devices with V\ulcorner of 0.77V and Tox=7.6nm is 360$mutextrm{A}$ /${\mu}{\textrm}{m}$ at V\ulcorner\ulcorner=3.5V and V\ulcorner=2.5V. Improved breakdown characteristics were obtained and the BV\ulcorner\ulcorner\ulcorner(the drain voltage for 1 nA/${\mu}{\textrm}{m}$ of I\ulcorner at V=\ulcorner\ulcorner=0V) of the device with L\ulcorner\ulcorner=0.3${\mu}{\textrm}{m}$ under the floating body condition was as high as 3.7 V. Problems for the new scheme are also addressed and more advanced device structure based on the proposed scheme is proposed to solve the problems.