• 대한전자공학회논문지
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• 제20권5호
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• pp.31-36
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• 1983

W.L.S. 알고리즘을 이용한 간접 M. R. L C. 방식으로서 직류전동기의 속도를 마이크로프로세서 M6509를 사용하여 제어하였으며 이를 통하여 W.L.S. 알고리즘의 빠른 수렴속도와 부하변동에 잘 적응하는 특성을 고략하였다.

• 한국기계가공학회지
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• 제7권4호
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• pp.128-134
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• 2008

Models of the deposition heights in the uncontrolled laser aided direct metal deposition process are constructed for the enhancement of the process integrity. Linear and non-linear statistical models as well as fuzzy model are utilized as the modeling methods. The predictability of the models are evaluated with the values of the sum of square error. The algorithm to use the models in the feedback controlled system is suggested to increase the deposition height accuracy within a layer.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.169-172
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• 1999

Recently, the wavelet transform has been a new and powerful tool for signal processing. It is more suitable specially for the feature extraction and detection of non-stationary signals than traditional methods such as, the Fourier Transform(FT), the Fast Fourier Transform(FFT) and the Least Square Method etc. because of the characteristic of the multi-scale analysis and time-frequency domain localization. The wavelet transform has been developed for the analysis of PD pulse signal to raise in the progress of insulation degradation. In this paper, the wavelet transform was applied to one foundational method for feature extraction. For the obtain experimental data, a computer-aided partial discharge measurement system with a single acoustic sensor was used. If we are applying to the neural network method the accumulated data through the extracted feature, it is expected that we can detect the PD pulse signal in the insulation materials on the on-line.

• 인포메이션 디스플레이
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• 제15권5호
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• pp.22-32
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• 2014

The current research intends to quantify the surround luminance effects on the shape of spatial luminance CSF and to propose an image quality evaluation method that is adaptive to both surround luminance and spatial frequency of a given stimulus. The proposed image quality method extends to a model called SQRI[8]. The non-linear behaviour of the HVS was taken into account by using CSF. This model can be defined as the square root integration of multiplication between display MTF and CSF. It is assumed that image quality can be determined by considering the MTF of the imaging system and the CSF of human observers. The CSF term in the original SQRI model was replaced by the surround adaptive CSF quantified in this study and it is divided by the Fourier transform of a given stimulus. A few limitations of the current work should be addressed and revised in the future study. First, more accurate model predictions can be achievable when the actual display MTF is measured and used instead of the approximation. Then, a further improvement to the model prediction accuracy can be made when chromatic adaptation of the HVS is taken into account[45-46].

• 한국농공학회지
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• 제36권3호
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• pp.144-154
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• 1994

An efficient tidal model, TIDE which is an iterative type, nonlinear finite element model has developed for the analysis of the tidal movement in the coastal area which is characterized by irregular boundaries and bottom topography. Traditional time domain finite element models have been in difficulties with requirement for high eddy viscosity coefficients and small time steps to insure numerical instability. These problems are overcome by operating in the frequency domain with an elaborate grid system by combining the triangular and quadrilateral shape grids. Furthermore, in order to handle non-linearity which will be more significant in the shallow region, an iterative scheme with least square error minimization algorithm has been implemented in the model. The results of TIDE model are agreed with the analytical solutions in a rectangular channel under the condition of tidal waves entering the channel closed at one end.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권6호
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• pp.1379-1397
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• 2013

We consider a system where a licensed radio spectrum is shared by multiple primary users(PUs) and secondary users(SUs). As the spectrum of interest is licensed to primary network, power and channel allocation must be carried out within the cognitive radio network so that no excessive interference is caused to PUs. For this system, we study the joint beamforming and power allocation problem via game theory in this paper. The problem is formulated as a non-cooperative beamforming and power allocation game, subject to the interference constraints of PUs as well as the peak transmission power constraints of SUs. We design a joint beamforming and power allocation algorithm for maximizing the total throughput of SUs, which is implemented by alternating iteration of minimum mean square error based decision feedback beamforming and a best response based iterative power allocation algorithm. Simulation results show that the algorithm has better performance than an existing algorithm and can converge to a locally optimal sum utility.

• 의정연구
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• 제24권1호
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• pp.241-276
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• 2018

본 논문은 제4~6회 시 도의회의원 선거의 표의 등가성을 새로운 지수를 활용하여 측정한다. 본 연구에서 표의 등가성 측정을 위해 사용되는 코사인제곱지수는 계산의 편리성과 더불어 광역시 도 단위로 선거구획정이 이루어지는 시 도의회의원 선거에서 지역 내 인구동등성 정도를 파악하는 데 그 유용성이 크다. 경험적 분석 결과, 제4회 시 도의회의원 선거는 인구수 규모와 상관없이 자치구 시 군마다 일률적으로 2인의 의원을 선출함에 따라 선거구간 인구편차가 지나치게 커지면서 지역 내 인구동등성 정도가 낮게 나타났다. 이후 2007년 헌법재판소의 결정으로 2010년 제5회 시 도의회의원 선거부터는 인구편차 기준이 4:1로 강화됨에 따라 표의 등가성이 대폭 증가함을 알 수 있었다. 그러나 한편으로는 여러 선거에 걸쳐 농촌지역 선거구의 인구수 불균형문제, 도농 간의 과소 과다대표 문제가 지속되고 있음도 동시에 확인할 수 있었다. 이 연구는 지방의회 선거의 선거구획정이 인구대표성 같은 물리적 비교를 바탕으로 하는 획일적인 방식을 지양하고 다양한 기준과 지역의 동질적 가치를 반영하는 방향으로 이루어져야 한다는 점을 강조하며, 이에 대한 시론적 방안을 제시한다.

• KIEAE Journal
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• 제7권4호
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• pp.147-152
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• 2007

Numerous non-destructive tests(NDT) to assess the safety of real structures have been developed. System identification(SI) techniques using dynamic responses and behaviors of structural systems become an outstanding issue of researchers. However the conventional SI techniques are identified to be non-practical to the complex and tall buildings, due to limitation of the availability of an accurate data that is magnitude or location of external loads. In most SI approaches, the information on input loading and output responses must be known. In many cases, measuring the input information may take most of the resources, and it is very difficult to accurately measure the input information during actual vibrations of practical importance, e.g., earthquakes, winds, micro seismic tremors, and mechanical vibration. However, the desirability and application potential of SI to real structures could be highly improved if an algorithm is available that can estimate structural parameters based on the response data alone without the input information. Thus a technique to estimate structural properties of building without input measurement data and using limited response is essential in structural health monitoring. In this study, shaking table tests on three-story plane frame steel structures were performed. Out-put only model analysis on the measured data was performed, and the dynamic properties were inverse analyzed using least square method in time domain. In results damage detection was performed in each member level, which was performed at story level in conventional SI techniques of frequency domain.

• 대한조선학회논문집
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• 제53권4호
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• pp.315-328
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• 2016

Techniques for determinating hydrodynamic derivatives of underwater tow-fish using CFD(Computational Fluid Dynamics) are described in this paper. Main components of hydrodynamic derivatives are added mass, linear damping and non-linear damping coefficients. In this study, linear and non-linear damping coefficients for translational velocities are settled by CFD analysis. In order to analyze the underwater tow-fish, UlsanFOAM based on open-source CFD code, namely OpenFOAM, is employed. By simulating pitch and yaw angle variation of underwater tow-fish, 6DOF(Degree-of-Freedom) forces and moments are estimated at each attitudes. In order to determinate the hydrodynamic derivatives, curves(forces and moments vs attitude) for CFD results are fitted by least square methods. To demonstrate the applicability of the current approach, two different problems(impulsive side towing and straight towing) are simulated and all results are validated.

• 농업과학연구
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• 제47권3호
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• pp.633-644
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• 2020

Rice paper is an element of Vietnamese cuisine that can be used to wrap vegetables and meat. Rice and starch are the main ingredients of rice paper and their mixing ratio is important for quality control. In a commercial factory, assessment of food safety and quantitative supply is a challenging issue. A rapid and non-destructive monitoring system is therefore necessary in commercial production systems to ensure the food safety of rice and starch flour for the rice paper wrap. In this study, fluorescence hyperspectral imaging technology was applied to classify grain flours. Using the 3D hyper cube of fluorescence hyperspectral imaging (fHSI, 420 - 730 nm), spectral and spatial data and chemometric methods were applied to detect and classify flours. Eight flours (rice: 4, starch: 4) were prepared and hyperspectral images were acquired in a 5 (L) × 5 (W) × 1.5 (H) cm container. Linear discriminant analysis (LDA), partial least square discriminant analysis (PLSDA), support vector machine (SVM), classification and regression tree (CART), and random forest (RF) with a few preprocessing methods (multivariate scatter correction [MSC], 1^st and 2^nd derivative and moving average) were applied to classify grain flours and the accuracy was compared using a confusion matrix (accuracy and kappa coefficient). LDA with moving average showed the highest accuracy at A = 0.9362 (K = 0.9270). 1D convolutional neural network (CNN) demonstrated a classification result of A = 0.94 and showed improved classification results between mimyeon flour (MF)1 and MF2 of 0.72 and 0.87, respectively. In this study, the potential of non-destructive detection and classification of grain flours using fHSI technology and machine learning methods was demonstrated.