• Journal of IKEEE
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• v.18 no.3
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• pp.398-402
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• 2014

In this paper, we propose a parallel processing method of pedestrian detection algorithm based on ROI-CENTRIST. There is a difficulty in the real-time processing of pedestrian detection in the embedded environment, using the conventional pedestrian detection method. This problem can be solved by a parallel processing method of applying the ROI to the conventional algorithm. The proposed parallel processing method of pedestrian detection using ROI-CENTRIST show the result of 5.2 frames per second, which is about 10% improvement over the conventional pedestrian detection method based on CENTRIST.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.10
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• pp.1688-1695
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• 2008

Recently, it is common in a distribution system of Korea Electric Power Corporation (KEPCO) to find instances where distribution lines are parallel. A traditional method of an induced voltage calculation is not suitable for parallel distribution lines. For more actual analysis of induced voltage on telecommunication lines in parallel distribution lines, a new calculation method is needed. This paper presents a new calculation method of an induced voltage on telecommunication line using equivalent ${\pi}$ circuits matrix in parallel distribution lines. The advantages of the calculation method are using actual neutral current value and not using screening factor for considering the overhead ground wire and the neutral wire. To verify the effectiveness and the accuracy of the method, various case studies are performed with EMTP(Electro-Magnetic Transients Program).

• The Journal of the Acoustical Society of Korea
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• v.12 no.2
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• pp.5-13
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• 1993

The purpose of this paper is to suggest and analyze the parallel algorithm for merging two heaps, on SIMD-SM-R parallel computer. In order to create the parallel algorithm for merging two heaps, we have classified two subproblems. For the first method, to select node p as a LEVEL-FIND function, Wyllie(19) suggests the method with time complexity O(log n) while this thesis has O(log(n/k)). For the second method, to merge two subheap, our algorithm has O(log(n/k)*log(n)) using max(2**(i-1), 「(m+1)/4」)'s processors while Dekel and Sahni(4)'s method and Hong's method(18) have O(log m). Also our parallel algorithm's EPU is close to 1 and so has an optimal speed-up ratio.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.81-84
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• 2003

For increasing power of photovoltaic systems, serial and parallel connection needed. In parallel connection, a desirable characteristic of parallel-connected 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, and the other is Active current-sharing. In Droop method, current distribution characteristics relies on the high output impedance of each converter. This scheme is more simple and no need interconnections. but also has a disadvantages of degrading current sharing characteristics. In this paper, using droop method at multiful-parallel connection with it's convenience and simplicity.

• Journal of the Korean Mathematical Society
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• v.52 no.2
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• pp.373-388
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• 2015

In this paper, a novel parallel hybrid iterative method is proposed for finding a common element of the set of solutions of a system of equilibrium problems, the set of solutions of variational inequalities for inverse strongly monotone mappings and the set of fixed points of a finite family of nonexpansive mappings in Hilbert space. Strong convergence theorem is proved for the sequence generated by the scheme. Finally, a parallel iterative algorithm for two finite families of variational inequalities and nonexpansive mappings is established.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.7
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• pp.1059-1065
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• 2017

In this paper, the energy harvester with a piezoelectric materials is modeled as the electric equivalent circuit, and performances of a standard DC method and a Parallel-SSHI method are verified through experiment under variable force and load conditions. Piezoelectric generator consists of mass, damper and spring constant, and it is modeled by electrical equivalent circuit with RLC components. Standard DC and Parallel-SSHI are used as power conversion methods, and standard DC consists of full-bridge rectifier and smoothing capacitor. Parallel-SSHI method is composed of L-C resonant circuit, zero-crossing detector and full-bridge rectifier. In case of simulation under $100k{\Omega}$ load condition, the harvested power is $500{\mu}W$ in Standard DC and $670{\mu}W$ in Parallel-SSHI, respectively. In experiment, the harvested power under $100k{\Omega}$ load condition is $420{\mu}W$ in standard DC and $602{\mu}W$ in Parallel-SSHI. Harvested power of Parallel-SSHI is improved by approximately 40% more than that of standard DC method.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.8
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• pp.475-481
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• 2005

In the existing ICT technique, the mounted electronic devices on the printed circuit board are tested whether the devices are good or not by comparing and measuring the value of the devices after separating the devices to be tested from around it based on the guarding method. But, in case that resistance, inductor and capacitor are configured as a parallel circuit on the circuit pattern, values for each device can not be measured because the total impedance value of the parallel circuit is measured. Accordingly, it is impossible to test whether the parallel circuit is good or not in case that the measured impedance value is within the tolerance error. Also, it is difficult to identify that which device among R, L and C of the parallel circuit is bad in case that the measured impedance value is out of the tolerance error. Accordingly, this paper proposes a test method which can enhance the quality and productivity by separating and measuring accurately R, L and C components from the RLC parallel circuits on the device-mounted printed circuit board. First, the RLC parallel circuit to be test is separated electrically from around it using three-terminal guarding technique. And then R, L and C values are computed based on the total impedance values and phase angles between voltage and current of the parallel circuit measured from two AC input signals with other frequency, Finally, the availability and accuracy of the proposed test method is verified by reviewing the simulation results.

• Honam Mathematical Journal
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• v.37 no.3
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• pp.299-315
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• 2015

In this paper, we study the first-order system least-squares (FOSLS) spectral method for parabolic partial differential equations. There were lots of least-squares approaches to solve elliptic partial differential equations using finite element approximation. Also, some approaches using spectral methods have been studied in recent. In order to solve the parabolic partial differential equations in parallel, we consider a parallel numerical method based on a hybrid method of the frequency-domain method and first-order system least-squares method. First, we transform the parabolic problem in the space-time domain to the elliptic problems in the space-frequency domain. Second, we solve each elliptic problem in parallel for some frequencies using the first-order system least-squares method. And then we take the discrete inverse Fourier transforms in order to obtain the approximate solution in the space-time domain. We will introduce such a hybrid method and then present a numerical experiment.

• Journal of the Institute of Convergence Signal Processing
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• v.16 no.3
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• pp.83-89
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• 2015

Connected component labeling (CCL) is a mandatory step in image segmentation where objects are extracted and uniquely labeled. CCL is a computationally expensive operation and thus is often done in parallel processing framework to reduce execution time. Various parallel CCL methods have been proposed in the literature. Among them are NSZ label equivalence (NSZ-LE) method, modified 8 directional label selection (M8DLS) method, HYBRID1 method, and HYBRID2 method. Soh et al. showed that HYBRID2 outperforms the others and is the best so far. In this paper we propose a new hybrid parallel CCL algorithm termed as HYBRID3 that combines selective four directional label search (S4DLS) with label backtracking (LB). We show that the average percentage speedup of the proposed over M8DLS is around 60% more than that of HYBRID2 over M8DLS for various kinds of images.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.235-240
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• 2007

A large power fuel cell generation system needs a parallel operation of de-de boost converter. Therefore, this paper proposed parallel operation algorithms of de-de boost converters for the large scale fuel cell generation system of 250[kW] and the operating principle along with the control method in detail. This paper uses a maximum current sharing method as a parallel operation method and also the phase shift full bridge de-de converter as a de-de boost converter. Simulation and experimental results on two prototype converter modules of 500W show that the parallel operation method can be applied to the 250[kW] power converter.