• 대한수학회보
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• 제55권5호
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• pp.1587-1598
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• 2018

We study additive decompositions (and generalized additive decompositions with a zero-dimensional scheme instead of a finite sum of rank 1 tensors), which are not of minimal degree (for sums of rank 1 tensors with more terms than the rank of the tensor, for a zero-dimensional scheme a degree higher than the cactus rank of the tensor). We prove their existence for all degrees higher than the rank of the tensor and, with strong assumptions, higher than the cactus rank of the tensor. Examples show that additional assumptions are needed to get the minimally spanning scheme of degree cactus +1.

• 한국항행학회논문지
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• 제13권5호
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• pp.720-725
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• 2009

본 논문은 월킨슨 전력 분배기에서 고립 특성을 확보하기 위해 사용된 100오옴의 연결을 0도 CRLH 전송선로를 사용한 변형된 전력 분배기를 제안하였다. 여기서 사용된 0도 CRLH 전송선로는 위상이 음의 특성을 갖는 RH(Right-Handed) 전송선로와 양의 특성을 가지는 LH (Left-Handed) 전송선로의 결합하여 전체 전기적 길이가 0도가 되는 특성을 갖고 있다. 0도 CRLH 전송선로를 $-30^{\circ}$의 RH 전송선로와 $+30^{\circ}$의 LH 전송선로의 전기적 길이를 선택하여 2-way 전력분배기의 특성을 확인한 결과는 중심주파수 1GHz에서 -3.3dB의 S21과 -27.5dB의 S11 그리고 -25dB 이상의 S23특성을 얻었다. 이 특성은 기존의 RH 전송선로를 이용한 것과 동일함을 확인하였다.

• 한국항해학회지
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• 제17권4호
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• pp.43-51
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• 1993

The purposes of this study are to make an analysis the sensible degree in Korea by using the formulas prepared by Watanabe, and to divide the climatic classification by the sensible degree in order to apply in practical life. Most data(air temperature, relative humidity, wind velocity, atmospheric pressure) are extracted from the "Climatic Table of Korea, Volume II(1961~1990)" issued by the Korea Meteorological Administration. As a result of this study, distribution patterns of the sensible degree are similar to isotherms when the wind velocity is zero, and then the sensible degrees are reduced with the increase of latitude. And western coastal and inland regions have larger values than eastern coastal regions in summer. However, the cont-rary distributions are shown in winter. When the wind velocity is not zero, distribution patterns of the sensible degree are influenced by the wind velocity. In summer, the values of central and southern inland regions are especially higher than the coastal regions, and most northern districts and some inland regions (Kangnung, Ulchin, Yongju etc.) have low values in winter. Then, the climate of Korea is divided into four patterns as follows : Yow means the sensible degree when the wind velocity is zero in winter. Yow > 3 : Jeju Island and southern coastal regions Yow = 0~3 : Most southern district and eastern coastal regions of central districts Yow = -3~0 : Most central districts and some eastern coastal regions (Hamheung, Youngheung, Won-san etc.) of northern districts Yow < -3 : Most northern districts and some inland regions(Inje, Hongcheon, Yang-pyeong etc.) of cent-ral districts.districts.

• 대한수학회지
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• 제50권2호
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• pp.445-464
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• 2013

We describe the one-dimensional and zero-dimensional cusps of the Satake compactification for the paramodular groups in degree two for arbitrary levels. We determine the crossings of the one-dimensional cusps. Applications to computing the dimensions of Siegel modular forms are given.

• 대한치과보철학회:학술대회논문집
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• 대한치과보철학회 1992년도 춘계학술대회
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• pp.16-17
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• 1992

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.428-433
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• 1994

This investigates the feasibility of applying fuzzy ogic controllers to the motion tracking control of a direct drive robot manipulator to deal with highly nonlinear and time-varying dynamics associated with robot motion. A fuzzy logic controller with narrow shape of membership functions near zero and wide shape far away zero is analyzed. Simulation and experimental studies have been conducted for a 2 degree of freedom direct drive SCARA robot to evaluate control performances, Fuzzy logic controllers have shown control performances that are often better, or at least, as good as those of conventional PID controllers. Furthermore, the control performance of fuzzy logic controllers can be improved by selecting membership functions of narrow shapes near zero and wide shapes far away zero.

• 한국군사과학기술학회지
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• 제10권1호
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• pp.33-43
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• 2007

Using the more common conventional chordwise aerodynamic approach, flapping a flat plate wing with zero degree chordwise pitch angle of attack and no relative wind should not produce lift. However, in hover, with no forward relative velocity and zero degree chordwise pitch angle of attack, flapping flat plate wings does in fact produce lift. In the experiments peformed for this paper, the flapping motion is considered pure(downstroke and upstroke) with no flapping stroke plane inclination angle. No changes in chordwise pitch angle are made. The total force is measured using a force transducer and the net aerodynamic force is determined from this measured total force by subtracting the experimentally determined inertial contribution. These experiments were repeated at various flapping frequencies and for various wing planform sizes for flat plate wings. The trends in the aerodynamic lift variation found using a force transducer have nearly identical shape for various flapping frequencies and wing planform sizes.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.948-953
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• 2004

For stable walking of various biped walking robots(BWR), we need to know the kinematics, dynamics and the Zero Moment of Point(ZMP) which are not easy to analyze analytically. In this reason, we developed a simulation program for BWRs composed of 4 degree-of-freedom upper-part body and 12 degree-of-freedom lower-part of the body. To operate the motion simulator for analyzing the kinematics and dynamics of BWES, inputs for the distance between legs, base angle, choice of walking type, gaits, and walking velocity are necessary. As a result, if stability condition is satisfied by the simulation, angle data for each actuator are generated automatically, and the data are transmitted to BWRS and then, they are actuated by the motion data. Finally, we validate the performance of the proposed motion simulator by applying it to a constructed small sized BWR.

• 대한수학회지
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• 제48권4호
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• pp.727-747
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• 2011

By employing coincidence degree theory and using Halanay-type inequality technique, a sufficient condition is given to guarantee the existence and global exponential stability of periodic solutions for the two-dimensional discrete-time Cohen-Grossberg BAM neural networks. Compared with the results in existing papers, in our result on the existence of periodic solution, the boundedness conditions on the activation are replaced with global Lipschitz conditions. In our result on the existence and global exponential stability of periodic solution, the assumptions in existing papers that the value of activation functions at zero is zero are removed.

• 대한전기학회논문지:전력기술부문A
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• 제53권10호
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• pp.542-549
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• 2004

The conventional fault location algorithms based on the travelling waves have an inherent problem. In cases of the close-up faults occurring near the relaying point and of the faults having zero degree inception angle of voltage signals, the conventional algorithms can not estimate an accurate fault distance. It is because the shapes of travelling waves are near sinusoidal in those cases. A new method solving this problem is presented in this paper. An FIR(Finite Impulse response) filter which makes high frequency components prominent and makes the power frequency component and dc-offset attenuated is used. With this method, the cross-correlation peak is to be very clear when a close-up fault or a fault having near zero-degree inception angle occurs. The cross-correlation peaks can be clearly distinguished and accurate fault location is practically possible consequently. A series of simulation studies using EMTP(Electromagnetic Transients Program) show that the proposed algorithm can calculate an accurate fault distance having maximum 2% or less error.