• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.3
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• pp.292-299
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• 2015

An envelope elimination and restoration transmitter that uses a tri-level envelope encoding scheme is presented for improving the efficiency and linearity of the system. The proposed structure amplifies the same magnitude signal regardless of the input peak-to-average power ratio and reduces the quantization noise by spreading out the noise to the out-of-band frequency, resulting in the enhancement of power efficiency. An improved linearity is also obtained by providing a new timing mismatch calibration technique between the envelope and phase signal. Implementation in a 130 nm CMOS process, transmitter measurements on a 20-MHz long-term evolution input signal show an error vector magnitude of 3.7 % and an adjacent channel leakage ratio of 37.5 dBc at 2.13 GHz carrier frequency.

• Journal of Wetlands Research
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• v.18 no.2
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• pp.148-153
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• 2016

Hydraulic and hydrological flood routing methods are commonly used to analyze temporal and spatial flood influences of flood wave through a river reach. Hydrological flood routing method has relatively more simple and reasonable performance accuracy compared to the hydraulic method. Storage constant used in Muskingum method widely applied in hydrological flood routing is very similar to the travel time. Focusing on this point, in this study, we estimate the travel time from HEC-RAS results to estimate storage constant, and develop a non-linear regression equation for the travel time using reach length, channel slope, and discharge. The estimated flow by Muskingum model with storage constant of nonlinear equation is compared with the flow calculated by applying the HEC-RAS 1-D unsteady flow simulation. In addition, this study examines the effect on the weighting factor changes and interval reach divisions; peak discharge increases with the bigger weighting factor, and RMSE decreases with the fragmented division.

• Journal of The Korean Digital Architecture Interior Association
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• v.5 no.1
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• pp.17-23
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• 2005

To begin with, this research arranged this concepts by analyzing paper a reference paper. So, the theory was arranged by approaching the ideal, formative and contemporary side. In order to type characteristics expression of organic design, after year 2000 printed in "Interiors" journal analyzed the contents based on interior works. 1. A type of metaphorical expression, order and the imitations of animals and plants. 2. A type of non liner, and dynamical balance and irregularity. 3. A type of mass of indeterminate form. 4. A type of fluidity by a curved line and a curved surface.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.3
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• pp.623-629
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• 2010

In this paper, a new robust variable structure controller based on a nonlinear integral type sliding surface is presented for the control of uncertain systems with mismatched uncertainties and disturbance. A nonlinear integral type sliding surface is suggested for removing the reaching phase. After its ideal sliding dynamics is obtained, the two design methods are presented. A corresponding control input is proposed to satisfy the closed loop stability in the sense of Lyapunov and the existence condition of the sliding mode on the nonlinear integral type sliding surface, which will be investigated in Theorem 1. Through a design example and simulation study, the usefulness of the proposed controller is verified.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.6
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• pp.1173-1178
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• 2010

In this note, a systematic design of a new robust nonlinear integral variable structure controller based on state dependent nonlinear form is presented for the control of uncertain more affine nonlinear systems with mismatched uncertainties and matched disturbance. After an affine uncertain nonlinear system is represented in the form of state dependent nonlinear system, a systematic design of a new robust nonlinear integral variable structure controller is presented. To be linear in the closed loop resultant dynamics and remove the reaching phase problems, the linear integral sliding surface is suggested. A corresponding control input is proposed to satisfy the closed loop exponential stability and the existence condition of the sliding mode on the linear integral sliding surface, which will be investigated in Theorem 1. Through a design example and simulation studies, the usefulness of the proposed controller is verified.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.9
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• pp.1754-1760
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• 2011

In this paper, a systematic design of a robust nonlinear multivariable variable structure controller based on state dependent nonlinear form is presented for the control of MIMO uncertain affine nonlinear systems with mismatched uncertainties and matched disturbance. After a MIMO uncertain affine nonlinear system is represented in the form of state dependent nonlinear system, a systematic design of a robust nonlinear variable structure controller is presented. To be linear in the closed loop resultant dynamics, the linear sliding surface is applied. A corresponding diagonalized control input is proposed to satisfy the closed loop global exponential stability and the existence condition of the sliding mode on the linear sliding surface, which will be investigated in Theorem 1. Through a design example and simulation study, the usefulness of the proposed controller is verified.

• Water for future
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• v.15 no.4
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• pp.39-44
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• 1982

A numerical computation of unsteady flow in the open channel was studied with the linearized four-point method of characteristics. A seiche test for this model was fulfilled and its result was very close to the exact solution. The effect of linearization to the accuracy of the result was small enough for the analysis of nearly horizontal flow, and this model would be applicable for the real unsteady flow problem because of its convenience.

• The Journal of Engineering Research
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• v.8 no.1
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• pp.59-65
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• 2006

본 논문에서는 마이크로폰 어레이 시스템을 이용하여 여러 화자의 음성 정보로부터 각 화자가 위치한 방향을 추정하는 기술 개발 내용을 다룬다. 성능 향상을 위한 전처리 과정으로 비선형 증폭기를 사용하여 거리에 따른 영향을 최소화하는 과정과 잡음에 대한 강인성을 얻기 위해 음성활성 영역을 검출하는 과정을 포함한다. 등간격으로 배치된 마이크로폰 어레이 시스템의 기하학적 특성에 따른 음원의 위치와 신호의 지연시간차이와의 상관관계로부터 화자의 위치를 역으로 추정하는 알고리즘을 기본으로 하여 가능성 척도를 계산하고 이를 활용하여 가능성이 높은 것들을 클러스터링하여 가능성이 있는 후보를 선정하여 화자의 방향을 검지한다. 이 과정에서 오인식을 최소화하기 위하여 가능성이 희박한 영역에 대한 추정 억제 방법으로 부정식 추론법을 적용하였다. 2 화자의 음성 신호를 입력으로 한 실험을 통하여 제안한 방법에 의한 다화자 방향검지의 가능성을 알아보았다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.5
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• pp.945-949
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• 2010

In this paper, a systematic design of a new robust nonlinear variable structure controller based on state dependent nonlinear form is presented for the control of uncertain affine nonlinear systems with mismatched uncertainties and matched disturbance. After an affine uncertain nonlinear system is represented in the form of state dependent nonlinear system, a systematic design of a new robust nonlinear variable structure controller is presented. To be linear in the closed loop resultant dynamics, the linear sliding surface is applied. A corresponding control input is proposed to satisfy the closed loop exponential stability and the existence condition of the sliding mode on the linear sliding surface, which will be investigated in Theorem 1. Through a design example and simulation study, the usefulness of the proposed controller is verified.

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.662-664
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• 2017

심실 내부에 가해지는 수축력에 의해 심실 내부 벽에는 큰 무리가 될 수 있다. 이로 인해 다양한 심장질환인 부정맥, 심실 세동 등을 유발한다. 따라서 본 연구에서는 가상 심장모델을 구축하여 컴퓨터 시뮬레이션을 통한 수축이완시의 심장 상태를 살펴보고자 하였다. 이를 위해서 개 심장 모델을 활용하여 3차원으로 이뤄진 심장모델을 구현하였다. 심장모델의 전기생리학 기전에 기초한 전기전도 해석을 수행하고, 전기전도 해석 시 발생되는 칼슘이온의 농도변화를 활용하였다. 시간에 따른 칼슘 이온의 심장 수축 영향을 바탕으로 비선형 유한요소법을 이용, 3차원 심장의 수축역학을 해석하였다. 이러한 기전으로 심장 근육에 부하되는 응력(tension)를 계산하고, 이렇게 계산된 심근의 응력분포에 대해 관측 및 분석을 진행하였다.