• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 전력전자학술대회 논문집
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• pp.150-151
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• 2014

높은 SOC(state-of-charge) 추정알고리즘의 성능을 위해서는 측정된 배터리 단자전압의 정확도가 요구된다. 그렇지만, 예기치 않은 에러로 인해 단자전압에 노이즈 성분이 추가될 경우 SOC 추정성능의 저하를 피할 수 없다. 그러므로, 본 논문에서는 이산 웨이블릿 변환(DWT;discrete wavelet transform)의 다해상도 분석(MRA;multi resolution analysis)의 디노이징(denoising)기법을 적용한 이차전지의 SOC 추정방법을 소개한다. MRA의 시간-주파수 분석을 통해 분해(decomposition)된 저주파 성분(approximation;$A_n$)과 고주파 성분(detail;$D_n$)중 노이즈에 관계된 $D_n$의 고주파 상세 계수(detail coefficient) $d_{j,k}$를 새로이 조정하고 이를 합성(synthesis)하여 디노이징을 마무리 한다. 확장 칼만필터(EKF;extended Kalman filter)의 비교 분석을 통해 제안된 방법의 타당성을 검증한다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.750-752
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• 2003

The objective of this investigation is to compare the geometric precision of Rigorous Sensor Model and Rational Function Model for QuickBird images. In rigorous sensor model, we use the on-board data and ground control points to fit an orbit; then, a least squares filtering technique is applied to collocate the orbit. In rational function model, we first use the rational polynomial coefficients provided by the satellite company. Then the systematic bias of the coefficients is compensated by an affine transformation using ground control points. Experimental results indicate that, the RFM provides a good approximation in the position accuracy.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.380-381
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• 2006

A technique to control the operating frequency of microstrip antenna by using the X-cut quartz substrate has been investigated experimentally and theoretically. We consider 6, 8 and 10 GHz resonance frequency in three dimensional quartz plates. Equation of linear piezoelectricity are solved for the thickness-shear approximation of X-cut quartz plates. At X-band frequencies, the microstrip antenna was voltage-controllable using the dc electric field dependence of the piezoelectric constant of X-cut quartz. This work demonstrates advantageous application for X-cut quartz plate in microstrip antenna substrates.

• 한국정밀공학회지
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• 제25권6호
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• pp.62-70
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• 2008

An adaptive fuzzy backstepping controller is proposed for the motion control for a single-link flexible-joint robot in the presence of parametric uncertainties. Fuzzy logic system is used to approximate the uncertainties of functions and a backstepping technique is employed to deal with the mismatched problem. A compensation controller is also employed to estimates the bound of approximation error so that the shattering effect of the control effort can be reduced. Thus the asymptotic stability of the closed loop control system can be obtained based on a Lyapunov synthesis approach. Numerical simulation results for a single-link flexible-joint robot are included to show the effectiveness of proposed controller.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.43.2-43
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• 2001

In this paper, we consider the problems of the evolutionary designed neural networks structures by genetic algorithm. Neural networks has been applied to various application fields since back-propagation algorithm was proposed, e.g. function approximation, pattern or character recognition and so on. However, one of difficulties to use the neural networks. It is how to design the structure of the neural network. Researchers and users design networks structures and training parameters such as learning rate and momentum rate and so on, by trial and error based on their experiences. In the case of designing large scales neural networks, it is very hard work for manually design by try and error. For this difficulty, various structural learning algorithms have been proposed. Especially, the technique of using genetic algorithm for networks structures design has been ...

• 대한원격탐사학회지
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• 제24권5호
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• pp.417-425
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• 2008

An image-based atmospheric correction software ATC is implemented using MATLAB and SML (Spatial Modeler Language in ERDAS IMAGINE), and it was tested using Landsat TM/ETM+ data. This ATC has two main functional modules, which are composed of a semiautomatic type and an automatic type. The semi-automatic functional module includes the Julian day (JD), Earth-Sun distance (ESD), solar zenith angle (SZA) and path radiance (PR), which are programmed as individual small functions. For the automatic functional module, these parameters are computed by using the header file of Landsat TM/ETM+. Three atmospheric correction algorithms are included: The apparent reflectance model (AR), one-percent dark object subtraction technique (DOS), and cosine approximation model (COST). The ACT is efficient as well as easy to use in a system with MATLAB and SML.

• Earthquakes and Structures
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• 제2권4호
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• pp.323-336
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• 2011

The problem of reconstruction of complete building response from a limited number of response measurements is considered. The response at the intermediate degrees of freedom is reconstructed by using piecewise cubic Hermite polynomial interpolation in time domain. The piecewise cubic Hermite polynomial interpolation is preferred over the spline interpolation due to its trend preserving character. It has been shown that factorization of response data in variable separable form via singular value decomposition can be used to derive the complete set of normal modes of the structural system. The time domain principal components can be used to derive empirical transfer functions from which the natural frequencies of the structural system can be identified by peak-picking technique. A reduced-rank approximation for the system flexibility matrix can be readily constructed from the identified mass-orthonormal mode shapes and natural frequencies.

• Structural Engineering and Mechanics
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• 제46권4호
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• pp.571-594
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• 2013

Railway truss bridges are amongst the essential structures in railway transportation. Minimization of the construction and maintenance costs of these trusses can effectively reduce investments in railway industries. In case of railway bridges, due to high ratio of the live load to the dead load, the moving load has considerable influence on the bridge dynamics. In this paper, optimization of the railway truss bridges under moving load is taken into consideration. The appropriate algorithm namely Hyper-sphere algorithm is used for this multifaceted problem. Through optimization the efficiency of the method successfully raised about 5 percent, compared with similar algorithms. The proposed optimization carried out on several typical railway trusses. The influences of buckling, deformation constraints, and the optimum height of each type of truss, assessed using a simple approximation method.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제23권3호
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• pp.157-178
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• 2019

The present correspondence is conveyed on to consider the fascinating and novel characteristics of radiative hydromagnetic convective flow of a chemically reacting fluid over an exponentially accelerated inclined porous plate. Exact solutions for the fluid velocity, temperature and species concentration, under Boussinesq approximation, are obtained in closed form by the two term perturbation technique. The interesting parts of thermal dispersing outcomes are accounted in this correspondence. Graphical evaluation is appeared to depict the trademark direct of introduced parameters on non dimensional velocity, temperature and concentration profiles. Also, the numerical assortment for skin friction coefficient, Nusselt number and Sherwood number is examined through tables. The certification of current examination is confirmed by making an examination with past revelations available in composing, which sets a benchmark for utilization of computational approach.

• Advances in nano research
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• 제13권1호
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• pp.77-86
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• 2022

This paper studied the peristaltic transport of upper convected Maxwell nanofluid through a porous medium in a heated (isothermal) symmetric vertical channel. The nanofluid is assumed to be electrically conducting in the presence of a uniform magnetic field. These phenomena are modeled mathematically by a differential equations system by taking low Reynolds number and long-wavelength approximation, the yield differential equations have solved analytically. A suggested new technique to display and discuss the trapping phenomenon is presented. We discussed and analyzed the pumping characteristics, heat function, flow velocity and trapping phenomena which were illustrated graphically through a set of figures for various values of parameters of the problem. The numerical results show that, there are remarkable effects on the vertical velocity, pressure gradient and trapping phenomena with the thermal change of the walls.