• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.8
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• pp.139-147
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• 2014

We address the problem of corrective control for two asynchronous sequential machines in parallel connection. Each asynchronous machine receives the same external input and shows independent state transition characteristics. We propose a novel control scheme in which only one corrective controller is employed so as to make the closed-loop system of each machine match the behavior of the corresponding reference model. Compared with the former method utilizing two corrective controllers, our scheme can reduce the controller size and computational load in controller design. We present the existence condition and design procedure for a state-feedback corrective controller under the assumption that the controlled machines are of input/state type. The design procedure for the proposed controller is described in an illustrative example.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.362-364
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• 2003

Generally, photovoltaic system is composed a number of solar cells array. so, virtual implementation module for solar cell array is needed Parallel connection each module for extract the power. A desirable characteristic of a parallel supply system is that individual converters share the load current equally and stably. The current sharing(CS) can be implemented using two approaches. The first one, known as a droop method, relies on the high output impedance of each converter. and The second approach, known as active current-sharing techniques. In this paper, analyze for better control logic of parallel connecting virtual implements of solar cell at using droop method.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.281-286
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• 1993

In this paper, a parallel link typed wrist is developed for robotic precision assembly. The developed wrist can make the corrective motion required for compensating lateral and tilting errors. The mechanism of this wrist is one example of a motion simulator generating 6 DOF motion in space by 6 actuators connected in paralle. To make the wrist more compact, miniature DC motors containing reduction gears and servo system were used. The parallel link architecture enables a high positioning accuracy and high nominal load capacity. In this study, inverse kinematic problem is solved by using a Denavet-Hartenberg method and a simulational result about workspace of the proposed parallel mechanism is obtained.

• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.957-960
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• 2003

Many solar cell way need to be connected by series or parallel to extract the high power Especially, during parallel operation to reduce circulation current the individual converter has to share and control the load current. Generally, Current Sharing(CS) can be implemented using droop and active current sharing method. In this paper, one 3[KW] PWM converter was replaced as one 3[KW] solar cell array(3 parallels, each parallel has twenty single modules), two 3[KW] solar cell way Is Paralleled to generate 6[KW] power. Also each converter used voltage-current controller and Automatic MSCPM(Master-Slave Current-programming Method) for current sharing(AS).

• Structural Engineering and Mechanics
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• v.12 no.2
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• pp.157-168
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• 2001

In this paper, experimental investigation into the behavior of reinforced concrete (RC) columns tested under large lateral displacement with four different types of loading arrangements is presented. Each loading arrangement has a different system for controlling the consistency of the loading condition. One of the loading arrangements used three units of link mechanism to control the parallelism of the top and bottom stub of column during testing, and the remaining employed eight hydraulic jacks for the same purpose. The loading systems condition used in this investigation were similar to the actual case in a moment-resisting frame where the tested column was displaced in a double curvature. Ten model column specimens, divided into four series were prepared. Two columns were tested monotonically until collapse, and unless failure took place at an earlier stage of loading, the remaining eight columns were tested under cyclic loading. Test results indicated that the proposed system to keep the top and bottom stubs parallel during testing performed well.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.97-100
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• 2001

A 3-way VLIW multimedia signal processor capable of efficient repeated operations as well as both load/store and type transformations for various data types is presented. It is composed of a 32-bit execution unit that can execute two instructions in parallel, an independent load/store unit and a control unit. The processor is implemented with 0.6${\mu}{\textrm}{m}$ gate array and the results are discussed.

• Journal of the Korea Computer Graphics Society
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• v.2 no.1
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• pp.24-30
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• 1996

The ray tracing method, which is one of many photorealistic rendering techniques, requires heavy computational processing to synthesize images. Parallel processing can be used to reduce the computational processing time. A parallel algorithm for the ray tracing has been implemented and executed for various images on transputer systems. In order to develop a scalable parallel algorithm, a processor farming technique has been exploited. Since each image is divided and distributed to each farming processor, the scalability of the parallel system and load balancing are achieved naturally in the proposed algorithm. Efficiency of the parallel algorithm is obtained up to 95% for nine processors. However, the best size of a distributed task is much higher in simple images due to less computational requirement for every pixel. Efficiency degradation is observed for large granularity tasks because of load unbalancing caused by the large task. Overall, transputer systems behave as good scalable parallel processing system with respect to the cost-performance ratio.

• Journal of Power Electronics
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• v.13 no.5
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• pp.757-765
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• 2013

For conventional interleaved two-phase forward converters with a common output inductor, the maximum duty cycle is 0.5, which limits the voltage range and increases the difficulty of the transformer's optimization. A new two-phase hybrid forward converter with series-parallel auto-regulated transformer windings is presented in this paper. With interleaved control signals for the two phases, the secondary windings of the transformers can work in series when the duty cycle is larger than 0.5, and they can work in parallel when duty cycle is lower than 0.5. Therefore, the maximum duty cycle is extended and the turns ratio of the transformer can be optimized. Duty cycle dependent auto-regulated windings result in the steady states of the converter being different in different duty cycle ranges (D>0.5 and D<0.5). Fortunately, the steady state gains of the proposed hybrid converter are identical at different duty cycle ranges, which means a stepless shift between two states. A prototype is built to verify the theoretical analysis. A conventional control loop is compatible for the whole input voltage range and load range thanks to the stepless shifting between the different duty cycle ranges.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.69-72
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• 2003

In this paper new control strategy of series resonant converter system for control power supply is suggested. Frequency controlled series resonant converter system is robust to load variations because it is POSR(parallel output series resonant) type. And it provides stable output voltage by changing switching frequency to input voltage variations. Firstly, operation analysis about suggested series resonant converter system was carried. Then simulations using ACSL(Advanced Continuous Simulation Language) and experiments to actual system were carried to prove characteristics of suggested system.

• Journal of Power Electronics
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• v.16 no.6
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• pp.2315-2326
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• 2016

This paper discusses the elimination of DC voltage deviation and the enhancement of load current sharing accuracy in multi-terminal high voltage direct current (MT-HVDC) systems. In order to minimize the power line losses in different parallel network topologies and to insure the stable operation of systems, a decentralized control method based on a modified droop control is presented in this paper. Averaging the DC output voltage and averaging the output current of two neighboring converters are employed to reduce the congestion of the communication network in a control system, and the decentralized control method is implemented. By minimizing the power loss of the cable, the optimal load current sharing proportion is derived in order to achieve rational current sharing among different converters. The validity of the proposed method using a low bandwidth communication (LBC) network for different topologies is verified. The influence of the parameters of the power cable on the control system stability is analyzed in detail. Finally, transient response simulations and experiments are performed to demonstrate the feasibility of the proposed control strategy for a MT-HVDC system.