• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.9
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• pp.838-849
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• 1991

An accurate approximation based on the integration of the characteristic function of the multiple access interference which consists of specular and scatter components is obtained for the average probability of error for asynchronous binary PSK direct sequence spread spectrum multiple access(DS/SSMA) communications system operating over nonselective fading channels with additive white Gaussian and impulsive noise channels.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.1
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• pp.11-19
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• 2013

As the temperature data show a distribution pattern with a number of peaks, assumption of normal distribution will result in a serious bias in the analysis. In this study, the Gaussian Mixture Distribution (GMD), a type of bimodal distribution, is presumed as a frequency distribution for the water temperature, in order to estimate the optimal parameter and to carry out the relation analysis between the optimal parameter and the basic statistical information such as mean and variance on the data. By the way, an estimation formulae to compute the frequency distribution of the data is developed by computing the parameters of GMD (i.e. ${\alpha}_1$, ${\mu}_1$, ${\sigma}_1$, ${\alpha}_2$, ${\mu}_2$, ${\sigma}_2$) by means of the major characteristic values, such as mean, standard deviation and skewness of the data. The formulae shows an excellent coincidence with the result from the observation data, in the RMS limit accuracy of 5%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.14 no.3
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• pp.280-292
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• 1989

In this paper, the error rate equations of digitally modulated signals transmitted through the channel which is not only Gaussian/Impulsive noise but also multi-path fading have been derived. Using the derived equations for the error probabilities of ASK, QAM, CPSK, DPSK, FSK, and MSK signals, the error rate performances of digital modulation systems have been evaluated and represented in the graphs as the functions of CNR, Impulsive indes, the ratio of Gaussian noise power component to Impulsive noise power component, and fading figures. The results show that, in the deep fading environment, the error is occurred more frequency by Gaussian noise than Impulsive noise. And the comparison of various systems certifies that PSK is superior to the ohter systems in the deep fading or shallow fading environment.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.768-772
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• 2011

본 논문에서는 켤레구배법을 이용해 전체-국부 확장함수를 지닌 일반유한요소법을 해석하는 방식을 제안한다. 이 기법은 편미분방정식의 해에 대한 정보가 충분하지 않은 경우에도 수치해석적인 방법으로 일반 유한요소법의 확장함수를 구성할 수 있으며 해석 과정 중 추가의 계산 없이 좋은 성능을 지닌 전처리값 및 초기 추측치를 활용할 수 있어 국부적으로 복잡한 거동을 보이는 문제의 해석에 유리하다. 본 논문에 포함된 수치해석 예제의 결과는 제안된 기법이 가우스 소거법과 같은 직접 솔버를 이용하는 경우보다 수치 해석적으로 더 효율적임을 보여준다.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.2
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• pp.115-122
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• 2012

We present here a new class of activation functions for neural networks, which herein will be called CosGauss function. This function is a cosine-modulated gaussian function. In contrast to the sigmoidal-, hyperbolic tangent- and gaussian activation functions, more ridges can be obtained by the CosGauss function. It will be proven that this function can be used to aproximate polynomials and step functions. The CosGauss function was tested with a Cascade-Correlation-Network of the multilayer structure on the Tic-Tac-Toe game and iris plants problems, and results are compared with those obtained with other activation functions.

• Journal of Korean Ophthalmic Optics Society
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• v.1 no.1
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• pp.29-39
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• 1996

We studied the method which would determine the appropriate additive damping factor for the damped least sequres(DLS) optimization. We calculated eigenvalues of the product of the Jacobian matrix of error function by using the singular value decomposition(SVD) method. While suitable damping factor was appiled to the additive DLS by using SVD and Gaussian elimination method, the convergence and stability of the optimization process were examined in a triplet-type camera lens-system where the condition number is well conditioned. We compared the convergence and stability of merit function when median, maximum and minimum of eigenvalues were used as a damping factor in the optimization process. When damping factor is median of eigenvalue, the convergence and stability of merit function are more excellent than in the case of two other eigenvalues. Thus, we adopt the median of eigenvalues as an appropriate damping factor. Next, by using SVD and Gaussian elimination method, we compound the convergence and stability of optimization process for triplet-type camera lens-system design. In these two method; triplet-type camera lens-system in which condition number is well conditioned, has little improvement with the combination of DLS and SVD.

• Journal of the Korean Data and Information Science Society
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• v.23 no.3
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• pp.487-494
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• 2012

This paper discusses a method for getting a basis set of estimable functions of model parameters in a two-way fixed effects model. Since the fixed effects model has more parameters than those that can be estimated, model parameters are not estimable. So it is not possible to make inferences for nonestimable functions of parameters. When the assumed model of matrix notation is reparameterized by the estimable functions in a basis set, it also discusses how to use projections for the estimation of estimable functions.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.2
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• pp.121-127
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• 2001

While SVD and Gaussian elimination method were applied to the additive damped least squares(DLS), the convergence and the stability of the optimization process were examined in a triplet-type camera lens-system where the condition number is well conditioned. DLS with SVD method generated a suitable merit function but this merit function may be trapped in a local minimum by the nonlinearity of error function. Therefore, the least camera lens-system was further designed by the global optimization method is grid method, and this method is adopted to get merit function that convergent to global minimum without local minimum trapping.

• Proceedings of the Korea Society of Elementary Mathematics Education
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• 2010.08a
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• pp.1-12
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• 2010

초등학교 6학년을 대상으로 6회 총 120분 동안 1996을 활용해서 1에서 100까지 수를 만들게 하는 활동을 한 결과를 제시하고 분석하였다. 이 퍼즐 과제 활동은 아이들의 수학적 사고를 많이 향상시켰으며, 수학적 성향을 강화시켰다. 특히, 이 과제에서 아이들은 협동의 이점을 알게 되었고 수학적 의사소통의 중요성도 경험하는 계기가 되었다. 무엇보다도 지수, 제곱근, 가우스 함수의 아이디어가 먼저 제시되고, 후속학습이 일어났다. 계산기가 어떻게 활용되어야 하는지에 대한 아이디어도 제공했다.

• Proceedings of the Optical Society of Korea Conference
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• 1988.06a
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• pp.47-54
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• 1988

아홉 개의 TEA Co 레이저선에 대한 암모니아 매질의 비선형 굴절계수 (n%)를, 매질을 통과한 광속이 self-focusing 또는 self-defocusing 에의해 겪게되는 공간적 광속 변화를 측정함으로써 결정하였다. 암모니아 매질을 통과하여 변형된 광속의 전장은 가우스 함수의 금수로 주어지는 스미스의 표현(5)으로 근사할수 있었으며, 실험치와 비교하여 보았다. 아홉 개의 레이저선중 여덟 개의 레이저선은 self-focusing 현상을 나타애렀으며9R(16) line은 self-defocusing 현상을 나타내었다.