• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.931-934
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• 2005

The scalar point multiplication operations is one of the most time-consuming components in elliptic curve cryptosystems. In this paper, we suggest how to induce the point-quadruple (4Q) operation by improving the double-and-add method, which has been a prevailing computing method for calculating the result of a scalar point multiplication. Induced and drived numerical expressions were evaluated and verified by a real application using C programming language. The induced algorithm can be applied to a various kind of calculations in elliptic curve operations more efficiently and by a faster implementation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.8B
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• pp.787-795
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• 2002

This paper presents the architecture and the implementation of a 2K/4K/8K-point complex Fast Fourier Transform(FFT) processor for Orthogonal Frequency-Division Multiplexing (OFDM) system. The architecture is based on the Cooley-Tukey algorithm for decomposing the long DFT into short length multi-dimensional DFTs. The transposition memory, shuffle memory, and memory mergence method are used for the efficient manipulation of data for multi-dimensional transforms. Booth algorithm and the COordinate Rotation DIgital Computer(CORDIC) processor are employed for the twiddle factor multiplications in each dimension. Also, for the CORDIC processor, a new twiddle factor generation method is proposed to obviate the ROM required for storing the twiddle factors. The overall 2K/4K/8K-FFT processor requires 600,000 gates, and it is implemented in 1.8 V, 0.18 ${\mu}m$ CMOS. The processor can perform 8K-point FFT in every 273 ${\mu}s$, 2K-point every 68.26 ${\mu}s$ at 30MHz, and the SNR is over 48dB, which are enough performances for the OFDM in DVB-T.

• Korean Journal of Oriental Medicine
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• v.1 no.1
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• pp.363-400
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• 1995

The electroacupuncture according to Voll(EAV) is a method of combining the fundamentals of classical acupuncture with the facilities of modern electronics for diagnostics and therapy. Classical acupuncture uses energy conducting lines called 'meridians' and acupuncture points situated along them. Dr. Voll is considered the founder of 'EAV' since he succeeded not only in finding a method of exact electric localization and in explaining the interelation between the acupuncture points and their individual organs, but he also succeeded in measuring the resistance of these points and in explaining the diagnostic meaning of the measured values. In the course of his research, Voll found numerous new measurement points and energy conducting vessels unknown to classical acupuncture, but indispensible for diagnosis of human organic functions. As a basis of modern research in meridian theory, I tried to compare EAV measurement point with classical acupuncture point.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.14 no.2
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• pp.93-111
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• 2010

The purpose of this paper is to obtain new complexity results for a second-order cone optimization (SOCO) problem. We define a proximity function for the SOCO by a kernel function. Furthermore we formulate an algorithm for a large-update primal-dual interior-point method (IPM) for the SOCO by using the proximity function and give its complexity analysis, and then we show that the new worst-case iteration bound for the IPM is $O(q\sqrt{N}(logN)^{\frac{q+1}{q}}log{\frac{N}{\epsilon})$, where $q{\geqq}1$.

• The KSFM Journal of Fluid Machinery
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• v.14 no.1
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• pp.18-23
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• 2011

The hydraulic part in reactor coolant pump consists of suction nozzle, impeller, diffuser, and discharge nozzle. Among them, impeller is required to be designed to satisfy performance requirements such as head, NPSHR, and head curve slope at design point. Present study is intended to suggest the preliminary design method sizing the impeller size to satisfy the design requirement particularly including head curve slope at design point. On a basis of preliminary design result, hydraulic components have been designed in detail by CFD and then manufactured in a reduced scale. Experiment in parallel with computational analysis has been executed in order to confirm the hydraulic performance. Comparison results show good agreement with design result, confirming the validity of design method suggested in this study.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.13 no.3
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• pp.189-202
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• 2009

In this paper we propose new primal-dual interior point algorithms for $P_*(\kappa)$ linear complementarity problems based on a new class of kernel functions which contains the kernel function in [8] as a special case. We show that the iteration bounds are $O((1+2\kappa)n^{\frac{9}{14}}\;log\;\frac{n{\mu}^0}{\epsilon}$) for large-update and $O((1+2\kappa)\sqrt{n}log\frac{n{\mu}^0}{\epsilon}$) for small-update methods, respectively. This iteration complexity for large-update methods improves the iteration complexity with a factor $n^{\frac{5}{14}}$ when compared with the method based on the classical logarithmic kernel function. For small-update, the iteration complexity is the best known bound for such methods.

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.1
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• pp.28-32
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• 2003

In this paper, we have studied the in-situ end point detection (EPD) for direct chemical mechanical polishing (CMP) of shallow trench isolation (STI) structures without the reverse moat etch process. In this case, we applied a high selectivity $1n (HSS) that improves the silicon oxide removal rate and maximizes oxide to nitride selectivity Quite reproducible EPD results were obtained, and the wafer-to-wafer thickness variation was significantly reduced compared with the conventional predetermined polishing time method without EPD. Therefore, it is possible to achieve a global planarization without the complicated reverse moat etch process. As a result, the STI-CMP process can be simplified and improved using the new EPD method.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.53-63
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• 2017

The increasing of wind power penetration level presents challenges in classical optimal reactive power dispatch (ORPD) which is usually formulated as a deterministic optimization problem. This paper proposes a two-stage stochastic programming model for ORPD by considering the uncertainties of wind speed and load in a specified time interval. To avoid the excessive operation, the schedule of compensators will be determined in the first-stage while accounting for the costs of adjusting the compensators (CACs). Under uncertainty effects, on-load tap changer (OLTC) and generator in the second-stage will compensate the mismatch caused by the first-stage decision. The objective of the proposed model is to minimize the sum of CACs and the expected energy loss. The stochastic behavior is formulated by three-point estimate method (TPEM) to convert the stochastic programming into equivalent deterministic problem. A hybrid Genetic Algorithm-Interior Point Method is utilized to solve this large-scale mixed-integer nonlinear stochastic problem. Two case studies on IEEE 14-bus and IEEE 118-bus system are provided to illustrate the effectiveness of the proposed method.

• The Journal of Korea Robotics Society
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• v.10 no.1
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• pp.33-41
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• 2015

Recent developments in robotics and intelligent vehicle area, bring interests of people in an autonomous driving ability and advanced driving assistance system. Especially fully automatic parking ability is one of the key issues of intelligent vehicles, and accurate parked vehicles detection is essential for this issue. In previous researches, many types of sensors are used for detecting vehicles, 2D LiDAR is popular since it offers accurate range information without preprocessing. The L shape feature is most popular 2D feature for vehicle detection, however it has an ambiguity on different objects such as building, bushes and this occurs misdetection problem. Therefore we propose the accurate vehicle detection method by using a 3D complete vehicle model in 3D point clouds acquired from front inclined 2D LiDAR. The proposed method is decomposed into two steps: vehicle candidate extraction, vehicle detection. By combination of L shape feature and point clouds segmentation, we extract the objects which are highly related to vehicles and apply 3D model to detect vehicles accurately. The method guarantees high detection performance and gives plentiful information for autonomous parking. To evaluate the method, we use various parking situation in complex urban scene data. Experimental results shows the qualitative and quantitative performance efficiently.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.6 s.97
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• pp.622-631
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• 2005

In this paper, we reduce 'over and under deviation' and 'over and under testing' which have a cause of uncertainty in electromagnetic radiated immunity test. We analyze continued measurement method of field uniformity and propose new estimate method having the minimum uncertainty condition. We test comparison in 4 anechoic chambers and analyze FDI(Field Deviation Index) which is the minimum deviation excess 6 dB on fields. We obtain that the proposed test method improve 1.193 dB than domestic standard(KN 61000-4-3) and 0.017 dB than international standard (IEC61000-4-3) in every frequency. In the test result 'over and under testing point' have 926 point at every field area and have 118 point at center uniform area. These result know that proposed measurement method have 10 point less at every field area and 9 point less at center uniform area than continued measurement method. The proposed test method have few point more than continued measurement method. Therefore, we confirmed that the proposed test method have the minimum uncertainty in electromagnetic radiated immunity test.