• Transactions on Control, Automation and Systems Engineering
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• v.3 no.1
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• pp.51-57
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• 2001

How to promote students interest is very important in undergraduate engineering education. One of the techniques for achieving this is select appropriate projects and to integrated them with regular courses. In this paper, a voice recognition system for autonomous robots is proposed as a project to educate students about microprocessors efficiently. The proposed system consists of a microprocessor and a voice recognition processor that can recognize a limited unmber of voice patterns. The commands of autono-mous robots are classified and are organized such that one voice recognition processor can distinguish robot commands under each directory. Thus. the proposed system can distinguish more voice commands than one voice recognition processor can. A voice com-mand systems for three autonomous robots is implemented with a microprocessor Inter 80CI196KC and a voice recognition processor HM2007. The advantages in integrating this system with regular courses are also described.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.1
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• pp.68-77
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• 1989

In this paper, a design approch is presented for a concurrent self-diagnosable microprocessor. An efficient diagnostic procedure to dynamically test the processor functional units decomposed by each insturction, concurrently with a program under execution is suggested. The basic goals of the proposed design approach are the low hardware overhead, no increase in the pin count and the minimal change of the initial design concepts on conventional microprocessors. The results of the performance of the suggested self-diagnosing hardware for an 8080 type microprocessor show that the suggested diagnosis scheme would be efficiently applicable, since diagnosing the processor functional units can be completed in a reasonably short time with the execution of an arbitrarily chosen sample program.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.2
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• pp.101-109
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• 2005

The newly developed speed sensorless control scheme is proposed to estimate both motor speed and rotor resistance simultaneously using variable rotor flux. The rotor flux is given as sinusoidal waveform with an amplitude and a frequency without affecting precise torque control. Especially the proposed method makes the simultaneous estimation of rotor resistance and speed with high precision even though at the low speed area including a few rpm. Moreover, on-line identification of rotor resistance can be performed simply without calculating troublesome trigonometric functions and complicated integral computation. Therefore, the proposed system can be accomplished by using very cheap microprocessors for several applications. The results of the numerical simulations and experiments demonstrate that this method is effective to estimate the speed and on-line identification of rotor resistance for sensorless induction motors.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2684-2686
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• 2001

In order to utilize cache in multiprocessor system, cache coherence problem must be handled. Central directory scheme is one of hardware-assisted cache coherence solutions. The goal of this paper was not only to propose some special methods needed to apply central directory scheme to the specific multiprocessor system based on Intel486 microprocessors but also to design central directory unit for cache coherence of the target system. The problems of arbitrating several requests from processors, storing the cache information, and generating control signals for cache line fill and snoop cycle were solved.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.6
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• pp.615-624
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• 1992

For the operation of the resonant DC link inverters, only limited number of modulation techniques such as the delta modulation and instantaneous current control techniques have been suggested. However, these modulation techniques have some limitations in practical operation. In this paper, the application of conventional inverter modulation techniques is suggested for the control of the resonant DC link inverter. The harmonic analysis results are presented. The results show that these modulation techniques offer good output characteristics similar to conventional inverter PWM techniques for the operation of the resonant DC link inverter. This implies that not only the delta modulation technique and instantaneous current control techniques but also various other modulation techniques can be applied to the operation of the resonant DC link inverter. This also indicates that open loop control as well as closed loop control can be used for the operation of the resonant inverter. The resonant DC link inverter with various modulation strategies is implemented using V-40 microprocessors.

• Journal of Power Electronics
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• v.4 no.2
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• pp.87-95
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• 2004

A new fast-response high-current clamp DC-DC converter circuit design is presented that will meet the requirements and features of the new generation of microprocessors and digital systems. The clamp in the proposed converter amplifies the current in case of severe load changes and is able to produce high slew rate of output current and capability to keep constant the output voltage. This proposed high-current clamp technique is theoretically loss less, low cost and easy to implement with simple control scheme. This is modified from a basic buck topology by replacing the output inductor with two magnetically coupled inductors. Inductors are difference in inductance, one has large inductance and other has small inductance. The inductor with small inductance will take over the output inductor during fast load transient. It speedup the output current slew rate and reduce the output voltage drop in the case of heavy burden load changes.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.128-130
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• 2003

Recently, with the increasing use of power semiconductors and microprocessors which are very sensitive to little change of power quality and power market being formed according to the reorganization of the power market, power providers and consumers show much interest in the power quality problem. This situation makes the demand creation of integrated system for power quality analysis and monitoring based on speedy and powerful functions by the growth of computer hardware and information technology, and besides advanced corporation already have created and employed power quality analysis and monitoring system. In this papers, it will be introduced that power quality database design-database is essential to integrated system-for managing effectively and confidently data from the power quality meters(PQM).

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.158-160
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• 2003

Recently, with the increasing use of power semiconductors and microprocessors which are very sensitive to little change of power quality and for coping positively with anticipating power quality disputes between power providers and consumers which are possible to occur by of power market being formed, the power quality problem has gained preponderance among the contemporary research areas. To serve these purposes, this paper is described the integrated system for power quality monitoring, which provides speedy and powerful functions by analyzing the Event data and diverse graphic interfaces for user.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1359-1361
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• 2003

As the maximum power operating point(MPOP) of Photovoltaic(PV) power generation systems changes with changing atmospheric conditions such as solar radiation and temperature, an important consideration. In the design of efficient PV system is to track the MPOP correctly. Many maximum power point tracking(MPPT) techniques have been considered in the past, however, techniques using microprocessors with appropriate MPPT algorithms are favored because of their flexibility and compatibility with different PV arrays. Although the efficiency of these MPPT algorithms is usually high, it drops noticeably in case of rapidly changing atmospheric conditions. This pager proposed a new MPPT algorithm based on perturb & observe(P&O) algorithm with experiment. The results shows that the new P&O algorithm has successfully tracked the MPOP, even in case of rapidly changing atmospheric conditions, and has higher efficiency than ordinary algorithms.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.6 no.6
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• pp.49-57
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• 1992

This paper proposes a Intel 8097 single-chip microprocessor based instantaneous voltage control scheme of inverter for UPS(Uninterruptible Power Supply). There microprocessors are used to control the output voltage and frequency of the inverter, the synchronization with by-pass, and the switching of the static switch. And the status and operating conditions of UPS systems is monitored by micro processor. The inverter output voltage is controlled instantaneously with a double regulation loop so that it has very good dynamic response for the varying loads or nonlinear loads as a rectifier. And also, the software and hardware of control system is described. From simulation and experimental results, it is shown that the proposed scheme has very good performance.