• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.2
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• pp.199-208
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• 2008

In this paper, to analyze the initial valued non-homogeneous elastic half space by the scaled boundary analysis, the infinite element approach was introduced. The free surface of the initial valued non-homogeneous elastic half space was modeled as a circumferential direction of boundary scaled boundary coordinate. The infinite element was used to represent the infinite length of the free surface. The initial value of material property(elastic modulus) was considered by the combination of the position of the scaling center and the power function of the radial direction. By use of the mapping type infinite element, the consistent elements formulation could be available. The performance and the feasibility of proposed approach are examined by two numerical examples.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.215-215
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• 2017

NRCS-CN 방법은 총 강우량으로부터 유출량을 계산하는 방법으로, 국내에서는 설계홍수량 산정 시 NRCS-CN 방법의 사용을 권장하고 있다. CN값은 토지이용 및 피복, 토양특성, 수문학적 조건(AMC)에 따른 함수로 결정할 수 있으나, 보통의 경우 미국의 National Engineering Handbook (NEH-4)에서 제시한 표를 활용한다. 그러나, 우리나라의 토지피복 및 토지이용 현황은 미국과 다르기 때문에 현실 조건을 반영한 조정이 필요함에도 불구하고, 충분한 관측 자료가 확보되지 않아 이러한 조정이 어려운 실정이다. NRCS-CN 방법에서는 결과 값이 총 강수량보다 CN에 크게 의존적이기 때문에 부정확한 CN 값의 산정은 큰 오차를 야기할 수 있다. 또한 소유역에서는 초기손실량이 설계홍수량 산정에 큰 영향을 미치지만 우리나라는 초기손실률을 20%의 고정된 값을 일괄적으로 적용하고 있으며, 이는 제주도와 같은 특수한 투수성 지층에서는 적합하지 않다는 지적을 받아왔다. 여러 선행연구에서 강수량과 CN 사이에는 특정 관계식이 존재하며, 고정된 CN 값이 아닌 강수량에 따라 변화하는 값을 적용하는 것이 기존의 NRCS-CN 방법보다 더 정확한 결과를 나타낸다는 것이 확인된 바 있다. 본 연구에서는 NRCS-CN 방법의 CN 값과 초기손실률을 유역에 적합하게 개선하기 위해서 기존의 NRCS-CN 모형에 점근 유출곡선지수방법(Asymptotic CN Regression Method)을 통해 산정된 CN값과 각기 다른 초기손실률(0.01, 0.05, 0.10, 0.20, 0.40)을 적용하여 개선된 총 8개의 모형을 한강 권역 소유역에 적용하였다. RMSE, MAE 및 R-square 등의 지표를 이용하여 모형 검정을 수행하였으며, 최적의 모형 및 미개변수를 선정하였다. 그 결과 기존의 NRCS-CN 방법보다 점근 유출곡선지수방법을 적용했을 때 더 작은 오차를 나타내는 것을 확인하였으며, 대부분의 유역에서 0.01 또는 0.05 등 기존보다 더 작은 초기손실률을 채택 시 실측값과 가장 적은 오차를 나타냈다.

• Journal of Advanced Navigation Technology
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• v.23 no.2
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• pp.214-220
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• 2019

The calibration method of the initial value error obtained in the weight measurement through anchor bolt type strain gauge sensor is proposed. The strain gauge sensor is developed for preventing the overturning of forklift, which is the most frequent type of safety-accident in industry. It was confirmed that the initial value error is caused from the physical and mechanical error of anchor bolt, and the environmental problem. Since the elimination of these causes falls outside the realm of this research, we find out the calibrated values based on all the causes, and we adjust the initial values of analog-to-digital convertor (ADC) module consisted of strain gauge sensor block using the calibrated values. We use the linear interpolation method for our calibration. We confirm that four sensor modules have the different under 5% between the real weight and the measured value in the experiment applied with the calibration of initial values. The low correlation between the real weights and ADC values is also improved through the proposed calibration.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.10
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• pp.575-587
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• 2004

In this paper. a new Fast Expectation-Maximization algorithm(FEM) is proposed. Firstly the K-means algorithm is modified to reduce the number of iterations for finding the initial values that are used as the initial values in EM process. Conventionally the Initial values in K-means clustering are chosen randomly. which sometimes forces the process of clustering converge to some undesired center points. Uniform partitioning method is added to the conventional K-means to extract the proper initial points for each clusters. Secondly the effect of posterior probability is emphasized such that the application of Maximum Likelihood Posterior(MLP) yields fast convergence. The proposed FEM strengthens the characteristics of conventional EM by reinforcing the speed of convergence. The superiority of FEM is demonstrated in experimental results by presenting the improvement results of EM and accelerating the speed of convergence in parameter estimation procedures.

• Journal of Practical Engineering Education
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• v.11 no.2
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• pp.291-303
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• 2019

The purpose of this research was to investigate the effect of the achievement goal orientation on college students' life satisfaction and sense of the belonging. This study used the analysis of the latent growth model to comprehend the slope of the 3 years longitudinal data. The result was that mastery approach and mastery avoidance affected the initial value of college life satisfaction, but not its slope as the time of 3 years went. On the other hand, performance approach was the opposite of mastery approach and mastery avoidance to college students' life satisfaction. Performance avoidance did not have an influence on both the initial value and the slope of college students' life satisfaction. The effect of the achievement goal orientation to the sense of belonging was also explored and its result was that mastery approach and mastery avoidance affected the initial value of the sense of belonging. However, it was different that performance approach did not influence the slope of the sense of belonging.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.1947-1954
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• 2012

The first frame is encoded in intra mode which generates a larger number of bits. In addition, the first frame is used for the inter mode encoding of the following frames. Thus the initial QP for the first frame affects the first frame as well as the following frames. Traditionally, the initial QP is determined among four constant values only depending on the bpp. In the case of low bit rate video coding, the initial QP value is fixed to 40 regardless of the output bandwidth. Although this initialization scheme is simple, yet it is not accurate enough. An accurate initial QP prediction scheme should not only depends on bpp but also on the complexity of the video sequence and the output bandwidth. In the proposed scheme, we determine the initial QP according to the ratio of the first frame to the total bits allocated to a GOP. To estimate the QP of the allocated bits, Rate-QP model is used. It is shown by experimental results that the new algorithm can predict the optimal initial QP more accurately and generate the PSNR performance better than that of the existing JVT algorithm.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.6
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• pp.1377-1383
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• 2012

The first frame of a GOP is encoded in intra mode which generates a larger number of bits. In addition, the first frame is used for the inter mode encoding of the following frames. Thus the intial QP for the first frame affects the first frame as well as the following frames. Traditionally, the initial QP is determined among four constant values only depending on the bpp. Although this initialization scheme is simple, yet it is not accurate enough. An accurate intial QP prediction scheme should not only depends on bpp but also on the complexity of the video sequence and the output bandwidth. In this paper, we propose a traffic model for finding the optimal initial QP which maximizes the PSNR of the GOP. We also propose a method to find model parameters for real-time video encoding. It is shown by experimental results that the proposed traffic model captures initial QP characteristics effectively and the proposed method for model parameters accurately estimates the real values.

• Computational Structural Engineering
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• v.11 no.1
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• pp.205-216
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• 1998

A solution method is presented to solve the eigenvalue problem arising in the dynamic analysis of nonclassicary damped structural systems with multiple eigenvalues. The proposed method is obtained by applying the modified Newton-Raphson technique and the orthonormal condition of the eigenvectors to the linear eigenproblem through matrix augmentation of the quadratic eigenvalue problem. In the iteration methods such as the inverse iteration method and the subspace iteration method, singularity may be occurred during the factorizing process when the shift value is close to an eigenvalue of the system. However, even though the shift value is an eigenvalue of the system, the proposed method provides nonsingularity, and that is analytically proved. Since the modified Newton-Raphson technique is adopted to the proposed method, initial values are need. Because the Lanczos method effectively produces better initial values than other methods, the results of the Lanczos method are taken as the initial values of the proposed method. Two numerical examples are presented to demonstrate the effectiveness of the proposed method and the results are compared with those of the well-known subspace iteration method and the Lanczos method.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.44-44
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• 2021

본 연구는 제주지역의 골프 코스에서 하절기 고온기간에 온도의 상승을 비롯한 다양한 환경변화로 인하여 생육 장애가 심한 한지형 잔디인 perennial ryegrass (Lolium perenne L.), Kentucky bluegrass (Poa pratensis L.), creeping bentgrass (Agrostis palustris Huds.) 3종에 대하여 엽록소형광과 엽록소지수를 측정하여 골프 코스와 스포츠 필드에서 잔디 선정과 관리를 위한 기본적인 정보를 얻기 위하여 수행하였다. F_o 값은 3종 모두 하절기 초기에는 낮고 후기에 다소 증가하는 양상을 보였다. 그러나, perennial ryegrass의 경우는 하절기 초기와 후기 간의 F_o 값의 변화가 컸으며, 특히, 후기에 F_o 값은 다른 2종 월등하게 보다 높았다. F_m 값은 3종 모두 하절기 초기에는 낮고 하절기 후기에 증가하였으나 3종 간의 차이는 크지 않았다. 광계 II의 광화학적 효율의 척도인 F_v/F_m 값은 3종 모두에서 하절기 초기에 낮고, 후기에 다소 증가하는 양상을 보였으나, 하절기 후기에 Kentucky bluegrass와 creeping bentgrass는 perennial ryegrass에 비해 F_v/F_m 값이 다소 높아 하절기 고온에서도 보다 더 잘 적응하는 것으로 보인다. 엽록소지수는 perennial ryegrass와 Kentucky bluegrass에서는 뚜렷하게 하절기 초기에는 낮고 후기에 높은 양상을 보였으나, creeping bentgrass는 조사기간 내내 낮은 상태를 유지하였다. 이상의 결과로부터 Kentucky bluegrass가 하절기 후기의 고온이나 빈번한 강우에 의한 습한 조건에 가장 강하고, perennial ryegrass가 가장 취약한 것으로 사료된다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.386-389
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• 2007

EBGM은 자세와 포즈, 조명 변화에 강인한 얼굴 인식 기법중의 하나이다. 하지만 EBGM을 통한 얼굴 인식 시스템은 얼굴의 특징점을 추출하기 위해 주어지는 초기값에 상당한 영향을 받는다. 이러한 문제를 해결하기 위해서 얼굴의 윤곽 추출에 우수한 성능을 보이는 AAM을 통하여 EBGM의 초기값을 주고 EBGM을 통하여 개선하는 방법을 제안하였었다. 본 논문에서는 등록자마다 다른 경계값을 갖는 방법을 제안한다. 기존의 경계값에 비해 성능의 향상이 어느 정도 이뤄지는가에 대해 다룰 것이다.