• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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• pp.179-180
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• 2008

Approximate equations for cylindrical breakdown voltages of planar pn junctions are proposed and verified. The equations show good agreement with the Baliga's results for rj/Wpp${\leq}0.3$ and with numerical results for rj/Wpp${\geq}0.3$ within 1 % error. Sensitivity of the breakdown voltage with respect to the doping concentrations is successfully derived using the approximate equations. The sensitivity formula can be utilized in the area of tolerance design of power semiconductor devices.

• 전기학회논문지
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• 제57권12호
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• pp.2234-2237
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• 2008

Approximate equations for cylindrical breakdown voltages of planar pn junctions are proposed and verified. The equations show good agreement with the Baliga's results for $r_{j}/Wpp{\leqq}0.3$ and with numerical results for $r_{j}/Wpp{\geqq}0.3$ within 1% error. Sensitivity of the breakdown voltage with respect to the doping concentrations is successfully derived using the approximate equations. The sensitivity formula can be utilized in the area of tolerance design of power semiconductor devices.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.751-752
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• 2013

• Journal of applied mathematics & informatics
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• 제30권1_2호
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• pp.135-145
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• 2012

Traditionally, ERM (Equivalent Random Method) is used to determine number of circuits in an overflow circuit group with rough traffic which has vmr(variance to mean ratio) greater than one. Recently, IPP(Interrupted Poisson Process) approximate method which represents the collective feature of the overflow has been introduced. The negative binomial loss formula can be applied to determine the required number of circuits in the overflow circuit group. In this paper, we deal with the negative binomial loss formula and determination method of number of circuits. We also analyze and compare these three loss formulas.

• 한국진공학회지
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• 제1권1호
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• pp.16-23
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• 1992

Conductance calculation is essential in designing a vacuum system. Since mathematical solution is nearly impossible except for a few simple cases, it has been so usual to calculate the conductance for a series connection of components using an approximate formula by Oatley. However, Oatley's formula has a fundamental flaw of totally neglecting the effect of gas beaming. In this study, a new technique is suggested for calculating the conductance with the same accuracy as the Monte Carlo method but with much less computing time, and applied to a system of tube connections in series. The effects of gas beaming in the calculation of conductance is analyzed quantitatively by comparing the conductance calculated by this method with those from Oatley's formula.

• 전자공학회논문지S
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• 제35S권4호
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• pp.105-117
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• 1998

In this paper, the general formula of disparity estimation based on Bayesian Maximum A Posteriori (MAP) algorithm is derived and implemented with simplified probabilistic models. The probabilistic models are independence and similarity among the neighboring disparities in the configuration.The formula is the generalized probabilistic diffusion equation based on Bayesian model, and can be implemented into the some different forms corresponding to the probabilistic models in the disparity neighborhood system or configuration. And, we proposed new probabilistic models in order to simplify the joint probability distribution of disparities in the configuration. According to the experimental results, the proposed algorithm outperformed the other ones, such as sum of swuared difference(SSD) based algorithm and Scharstein's method. We canconclude that the derived formular generalizes the probabilistic diffusion based on Bayesian MAP algorithm for disparity estimation, and the propsoed probabilistic models are reasonable and approximate the pure joint probability distribution very well with decreasing the computations to 0.01% of the generalized formula.

• 응용통계연구
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• 제29권1호
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• pp.181-192
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• 2016

옵션의 가격을 결정하는 문제에서 블랙-숄즈 모형이 가지는 단점을 보완하기 위해 블랙-숄즈 가격을 선도항으로 하여 보정항을 구하는 근사적 옵션가격의 결정방법을 고려하였다. 이러한 근사적 가격결정 방법들은 비교적 적은 자료를 가지고 간단한 계산으로 다양한 형태의 위험중립 확률분포에 의한 옵션가격을 계산할 수 있다. 이 논문에서는 일반적으로 관찰되는 시장상황을 모사한 모의실험과 실제 시장에서 관측되는 KOSPI200 옵션가격 자료를 통해 몇 가지 근사방법들의 적합성과를 비교, 평가하였다. 헤르미트 다항식 계열의 Edgeworth 확장과 A-type Gram-Charlier, C-type Gram-Charlier 방법, NIG 분포를 이용하는 방법, 비선형 회귀를 이용한 점근적 근사방법이 고려되었다. 모의실험에서는 순수 점프 레비 확률과정 가운데 옵션가격이 닫힌 해의 형태로 존재하는 Variance gamma 과정을 가정하여 자료를 생성하였다. 모의실험과 실제 자료분석의 결과, 분포함수를 먼저 근사하여 가격을 계산하는 것보다 근사적 가격식을 유도하여 직접 가격을 근사하는 방법들의 성능이 좀 더 좋았으며, 그 가운데 비선형 회귀를 이용한 점근적 근사방법이 상대적으로 좋은 성능을 보였다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1999년도 KOBA 방송기술 워크샵 KOBA Broadcasting Technology Workshop
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• pp.49-56
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• 1999

In this paper, the general formula of disparity estimation based on Bayesian Maximum A Posteriori (MAP) algorithm is derived. The generalized formula is implemented with the plane configuration model and applied to multiple baselined stereograms. The probabilistic plane configuration model consists of independence and similarity among the neighboring disparities in the configuration. The independence probabilistic model reduces the computation and guarantees the discontinuity at the object boundary region. The similarity model preserves the continuity or the high correlation of disparity distribution. In addition, we propose a hierarchical scheme of disparity compensation in the application to multiple-view stereo images. According to the experiments, the derived formula and the proposed estimation algorithm outperformed other ones. The proposed probabilistic models are reasonable and approximate the pure joint probability distribution very well with decreasing the computations to O(n(D)) from O(n(D)4) of the generalized formula. And, the hierarchical scheme of disparity compensation with multiple-view stereos improves the performance without any additional overhead to the decoder.

• 한국항공운항학회지
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• 제26권4호
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• pp.13-19
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• 2018

Master plan plans for new airports should estimate the approximate scale of the airside's moorings and terminals. The size of the pavilion can be determined by complex factors such as the operating hours of the operating company, the frequency of operation, and the aircraft class. Among them, the number of flights is calculated using the Horon-jeff equation because of the relationship between the number of flights and the time occupied by the mains. Since this estimation formula is a simplified formula, it is necessary to verify the appropriateness of the method of estimating the scale and to suggest improvement directions. Therefore, in this study, we propose a method of estimating the size of the western flags by investigating and analyzing the main airports of overseas airports to determine whether the application of the Horon-jeff formula is appropriate.

• Journal of Mechanical Science and Technology
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• 제15권8호
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• pp.1143-1155
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• 2001

In order to reduce the expensive CPU time for design sensitivity analysis in dynamic response optimization, this study introduces the design sensitivities approximated within estimated confidence radius in dynamic response optimization with ALM method. The confidence radius is estimated by the linear approximation with Hessian of quasi-Newton formula and qualifies the approximate gradient to be validly used during optimization process. In this study, if the design changes between consecutive iterations are within the estimated confidence radius, then the approximate gradients are accepted. Otherwise, the exact gradients are used such as analytical or finite differenced gradients. This hybrid design sensitivity analysis method is embedded in an in-house ALM based dynamic response optimizer, which solves three typical dynamic response optimization problems and one practical design problem for a tracked vehicle suspension system. The optimization results are compared with those of the conventional method that uses only exact gradients throughout optimization process. These comparisons show that the hybrid method is more efficient than the conventional method. Especially, in the tracked vehicle suspension system design, the proposed method yields 14 percent reduction of the total CPU time and the number of analyses than the conventional method, while giving similar optimum values.