• Journal of the Korean Geotechnical Society
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• v.21 no.4
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• pp.21-29
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• 2005

Lightweight Foamed Soil (LWFS) could be the substitute of normal soils used in backfill to earth structures and embankment materials far soft ground improvement in port and harbor project because of its effectiveness in settlement reduction and earth pressure decrease due to its lightness. A series of triaxial and unconfined compression tests were performed to investigate behaviors of LWFS composed of dredged soils, cement and air foam, and cured at underwater conditions. The density of LWFS will increase if LWFS is cured at underwater conditions because high water pressure makes air foam disappear or demolish during the curing compared with LWFS cured at normal air conditions. This paper is to find the mechanical behaviors of LWFS cured at seawater depth of 5.0 m and 10.0 m, respectively, which simulates underwater curing conditions by underwater pressure simulator chamber developed during this study. In addition, new normalized factor formula, which takes account of mixing design conditions determining compressive strength of LWFS, was proposed to consider mixing design factor fur LWFS.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.4
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• pp.45-50
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• 2004

In this paper, we propose a new PCA-based LDA Mixture Algorithm(PLMA) for real-time face recognition system. This system greatly consists of the two parts: 1) face extraction part; 2) face recognition part. In the face extraction part we applied subtraction image, color filtering, eyes and mouth region detection, and normalization method, and in the face recognition part we used the method mixing PCA and LDA in extracted face candidate region images. The existing recognition system using only PCA showed low recognition rates, and it is hard in the recognition system using only LDA to apply LDA to the input images as it is when the number of image pixels ire small as compared with the training set. To overcome these shortcomings, we reduced dimension as we apply PCA to the normalized images, and apply LDA to the compressed images, therefore it is possible for us to do real-time recognition, and we are also capable of improving recognition rates. We have experimented using self-organized DAUface database to evaluate the performance of the proposed system. The experimental results show that the proposed method outperform PCA, LDA and ICA method within the framework of recognition accuracy.

• Asia Marketing Journal
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• v.12 no.2
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• pp.135-154
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• 2010

This paper considers a duopoly where switching costs exist. The analysis proves that temporal price reductions can be pure strategy equilibrium where firms earn more profit than in a regular price strategy. Greater profits result from price discrimination in temporal price reductions. The equilibrium is contrasted with previous studies, which explain temporal price reductions as a result of mixed strategy. In a given model with an assumption about forming switching cost, firms can control their range of loyal consumers by properly setting their regular and promotional prices. The model shows that temporal price reduction tends to raise the regular price and decrease the range of loyal consumers.

• Journal of the Korean Institute of Telematics and Electronics
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• v.15 no.4
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• pp.14-19
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• 1978

Here a method is shown to extract features from two multi-variable classes by using the coordinate systems transformed by one-class and mixture normalization algorithms. Some properties and implemented results of this technique are described. Also, comparision of these features with factor analysis results is performed. This method is thought to be more powerful one, in feature extraction sense, than factor analysis.

• Proceedings of the Korea Contents Association Conference
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• 2013.05a
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• pp.109-110
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• 2013

도심화는 녹지의 제거로 인해 야기괴는 다양한 환경문제를 일으킨다. 이러한 도심화 현상은 종종 원격탐사영상을 이용하여 평가되는데, 대표적으로 정규식생지수와 지표온도를 통해 이루어진다. 그러나 식생지수는 두 개의 광학채널을 이용하기 때문에 식생이 아닌 도심지에서 식생과 같은 지수를 나타나는 오류가 발생한다. 이에 본 연구에서는 도심지에서 정규식생지수와 지표온도가 도심지 표면의 물질의 혼합에 따라 어떻게 변화하는지 관찰하였다.

• Journal of the Korean Geotechnical Society
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• v.17 no.4
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• pp.7-14
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• 2001

구조물 하중에 의한 점성토 지반의 침하량을 보다 정확하게 평가하기 위해서는 지반 내의 흙요소가 경험하는 실제적인 응력경로와 이에 따른 변형양상이 적절하게 고려되어야만 한다. 따라서 본 연구에서는 축대칭 조건의 다양한 응력경로를 따라 발생하는 정규압밀 점성토의 변형 거동을 고찰한 기존의 실험적 연구결과를 바탕으로 응력경로법에 근거한 보다 간편하고 합리적인 침하량 평가기법을 제시하였다. 또한 본 연구에서는 제시된 평가기법을 기존의 1차원적인 침하량 평가기법들과 함께 실제와 유사한 조건을 가지는 가상지반의 침하량 산정에 적용해 보았으며, 동일한 조건에 대해 소성모델(MCC 모델)과 혼합압밀이론에 바탕을 둔 유한요소해석을 실시하였다. 그리고 이를 통해 얻어진 결과들을 비교.분석함으로써 기존 평가기법들의 문제점과 한계를 명확히 제시하였으며, 응력증분 평가방법이 침하량 평가에 미치는 영향을 분석하였다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.4
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• pp.365-373
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• 2010

A chemical reactor model (CRM) was developed for a jet stirred reactor (JSR) to predict the emission of exhaust such as NOx. In this study, a two-PSR model was chosen as the chemical reactor model for the JSR. The predictions of NO formation in lean premixed methane-air combustion in the JSR were carried out by using CHEMKIN and GRI 3.0 methane-air combustion mechanism which include the four NO formation mechanisms. The calculated results were compared with Rutar's experimental data for the validation of the model. The effects of important parameters on NO formation and the contributions of the four NO pathways were investigated. In the flame region, the major pathway is the prompt mechanism, and in the post flame region, the major pathway is the Zelodovich mechanism. Under the lean premixed condition, the N2O mechanism is the important pathway in both flame and postflame regions.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.968-976
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• 2004

In the paper, deformation characteristics of fiber-mixed-soils, mixed polypropylene staple fibers of 0.3% fiber content with sands of various gradation, and their effectiveness of reinforcement were evaluated. A series of Resonant Column tests were performed with specimens prepared with varying Uniformity Coefficient and constant Curvature Coefficient. Maximum shear moduli 01 fiber-mixed-soils were increased by up to 30% and modulus reduction was also restrained in nonlinear range. Normalized shear modulus reduction curves of fiber-mixed-soils shift close to the upper limit of Seed curd Idriss's curves and are located within narrower band than those of unmixed soils, which proves the effectiveness on stiffness increment by reinforcing soils with fibers.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.5
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• pp.46-52
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• 2009

In this study the predictions of NOx in methane-air lean premixed combustion in PSR were carried out with GRI 3.0 methane-air combustion mechanism and Zeldovich, nitrous oxide, prompt, and NNH NO formation mechanism by using CHEMKIN code. The results are compared to the JSR experimental data of Rutar for the validation of the model. This study concerns about the importance of the chemical pathways. The chemical pathway most likely to form the NO in methane-air lean-premixed combustion was investigated. The results obtained with the 4 different NO mechanisms for residence time(0.5-1.6ms) and pressure(3, 4.7, 6.5 atm) are compared and discussed.

• Journal of the Korean Data and Information Science Society
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• v.21 no.5
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• pp.863-871
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• 2010

Until now, many studies related circular data are carried out, but the focuses are mainly on mildly peaked symmetric or asymmetric cases. In this paper we studied a modeling process for sharply peaked asymmetric circular data. By using wrapped Laplace, which was firstly introduced by Jammalamadaka and Kozbowski (2003), and its mixture distributions, we considered the model fitting problem of multi-modal circular data as well as unimodal one. In particular we suggested EM algorithm to find ML estimates of the mixture of wrapped Laplace distributions. Simulation results showed that the suggested EM algorithm is very accurate and useful.