• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.402-407
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• 2003

• Journal of the Korean Society of Safety
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• v.25 no.3
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• pp.22-27
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• 2010

A prediction performance of Fire Dynamics Simulator(FDS) developed by NIST for the diffusion flame structure was validated with experimental results of a laminar slot jet diffusion flame. Two mixture fraction combustion models and two finite chemistry combustion models were used in the FDS simulation for the validation of the jet diffusion flame structure. In order to enhance the prediction performance of flame structure, DNS and radiation model was applied to the simulation. The reaction rates of the finite chemistry combustion models were appropriately adjusted to the diffusion flame. The mixture fraction combustion model predicted the diffusion flame structure reasonably. A 1-step finite chemistry combustion model cannot predict the flame structure well, but the simulation results of a 2-step model were in good agreement with those of experiment except $CO_2$ concentration. It was identified that the 2-step model can be used in the investigation of flame suppression limit with further adjustment of reaction rates

• The Korean Journal of Applied Statistics
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• v.15 no.1
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• pp.57-71
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• 2002

We introduce three types of exponential survival models, such as simple model, change-point model and finite mixture model in this paper. Among these models, in order to choose the best model, the model choice method is proposed using Gelfand and Ghosh(1998)'s idea. Then to avoid the computational difficulties, data augmentation method (Tanner and Wong, 1987) and Gibbs sampler (Gelfand and Smith, 1990) are employed. Our methodology is applied to both simulated data and Stangl (1991)'s On-impramint Hydrochloride data.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.4
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• pp.609-628
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• 1995

This paper presents a reliability model and a data-analytic procedure for a repairable unit subject to failures due to multiple non-identifiable causes. We regard a failure cause as a state and assume the life distribution for each cause to be exponential. Then we represent the dependency among the causes by a Markov switching model(MSM) and estimate the transition probabilities and failure rates by maximum likelihood(ML) method. The failure data are incomplete due to masked causes of failures. We propose a specific version of EM(expectation and maximization) algorithm for finding maximum likelihood estimator(MLE) under this situation. We also develop statistical procedures for determining the number of significant states and for testing independency between state transitions. Our model requires only the successive failure times of a unit to perform the statistical analysis. It works well even when the causes of failures are fully masked, which overcomes the major deficiency of competing risk models. It does not require the assumption of stationarity or independency which is essential in mixture models. The stationary probabilities of states can be easily calculated from the transition probabilities estimated in our model, so it covers mixture models in general. The results of simulations show the consistency of estimation and accuracy gradually increasing according to the difference of failure rates and the frequency of transitions among the states.

• Journal of the Korean Society of Costume
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• v.61 no.8
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• pp.45-56
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• 2011

This study is about the features of hybridization of ethnic-cultural elements in Korean fashion magazines. Its purpose was to embody more creative and newer images in fashion by promoting better mutual understanding of foreign cultures and addressing the issues of fashion design from multicultural perspectives. In doing so, the present study conducted a literature review and analyzed a total of 130 photographic images with any hybrid ethic element from two Korean fashion magazines, Vogue Korea and Harper's Bazaar Korea, issued between 2005 and 2009. The analysis revealed that there were 66 images(50.8%) with a mixture of two different cultures and 64 images(49.2%) with a mixture of three or more different cultures. As seen from the results, the two categories had a similar number of cases. In regional terms, the use of two different cultural elements included a mixture of Asian and Western cultures in 32 images(24.6%), a mixture of Western and African, Middle Eastern or Latin American cultures in 23(17.7%), and a mixture of Western and Russian or European folk cultures in 11(8.5%). In the use of three or more different cultural/national elements, the present study found a mixture of Asian, African, Middle Eastern, Latin American and Western costume items in 20 photo images(15.4%), a mixture of African, Middle Eastern and Latin American elements plus Western costume items in 19 images( 14.6%), a mixture of all regional cultures in 13 photos(10%), and a mixture of Asian ethic cultures plus Western costume items in 12 cases(9.2%). The results of this analysis indicated that the hybridization of ethnic-culture elements in Korean fashion magazines consisted of diverse clothing and accessories from various ethnic groups. The expression of these multi-cultural hybrid images that consists background images and models from different cultures well-portrayed the multi-cultural elements based on total coordination and broke the stereotypical aspects of styling.

• Korean Journal of Food Science and Technology
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• v.38 no.3
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• pp.337-341
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• 2006

The quality characteristics of a surimi-based product with sea tangle single cell detritus (SCD) were studied in order to utilize SCD from sea tangle as a food additive. Mixture design and regression models were applied to optimize the processing conditions and to investigate the interaction between surimi and the other ingredients. Surimi and SCD decreased hardness and cohesiveness of surimi gels, and then increased them. Water increased hardness and then decreased it, whereas cohesiveness was reversed. Surimi and water increased gumminess and brittleness of surimi gels, but SCD decreased them. SCD increased water retention ability (WRA) and whiteness of surimi gels, whereas water decreased it. Hardness and cohesiveness fitted nonlinear models by ANOVA, but gumminess, brittleness, WRA and whiteness fitted linear models. The response constraint coefficient showed that surimi influenced hardness and whitenessmore than water and SCD, whereas water influenced WRA more than surimi and SCD. Moreover, SCD influenced cohesiveness, gumminess and brittleness more than surimi and water. Hardness and cohesiveness fitted nonlinear models with interaction terms for surimi-SCD and surimi-water, respectively. Optimum mixed ratio values of surimi, water, and SCD were 36.80, 57.07 and 4.14%, respectively, by mixture model.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.35-38
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• 2000

본 연구에서는 연속음성인식 시스템의 성능 향상을 위한 기초 연구로서 시스템에 적합한 음향모델과 언어모델을 작성하고 항공편 예약 태스크를 대상으로 인식실험을 실시한 결과 그 유효성을 확인하였다. 이를 위하여 먼저 HMM의 출력확률분포의 mixture와 파라미터의 차원에 대한 정확한 분석을 통한 음향모델을 작성하였다. 또한 반복학습법으로 특정 태스크를 대상으로 N-gram 언어모델을 적용하여 인식 시스템에 적합한 모델을 작성하였다. 인식실험에 있어서는 3인의 화자가 발성한 200문장에 대해 파라미터 차원 및 mixture의 변화에 따른 음향모델과 반복학습에 의해 작성한 언어모델에 대해 multi-pass 탐색 알고리즘을 이용하였다. 그 결과, 25차원에 대한 mixture 수가 9인 음향모델과 10회 반복 학습한 언어모델을 이용한 경우 평균 $81.0\%$의 인식률을 얻었으며, 38차원에 대한 mixture 수가 9인 음향모델과 10회 반복 학습한 언어모델을 이용한 경우 평균 $90.2\%$의 인식률을 보여 인식률 제고를 위해서는 38차원에 대한 mixture 수가 9인 음향모델과 10회 반복학습으로 작성한 언어모델을 이용한 경우가 매우 효과적임을 알 수 있었다.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.4
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• pp.733-739
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• 2012

In this paper, a smoke detection algorithm robust to brightness and color variations depending on time and weather is proposed. The proposed smoke detection algorithm specifies the candidate region using difference images of input and background images, determines smoke by comparing feature coefficients of Gaussian mixture model of difference images. Thresholds for specifying candidate region is divided by four levels according to average brightness and chrominance of input images. Clusters of Gaussian mixture models of difference images are aligned according to average brightness. Smoke is determined by comparing distance of Gaussian mixture model parameters. The proposed algorithm is implemented by media dedicated DSP. As results of experiments, it is shown that the proposed algorithm is effective to detect smoke with camera installed outdoor.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.5
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• pp.233-239
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• 2013

The Thermophysical properties of thermal conductivity, viscosity, and heat capacity for $CO_2$ slurry ($CO_2$ gas and $CO_2$-hydrate mixture) having a high gas phase volume fraction were predicted using the conventional mixture models and the TRAPP model under hydrate formation conditions. Based on the calculated thermophysical properties, the heat transfer coefficient and pressure drop of the $CO_2$ slurry in the tube were predicted. The thermal conductivity of $CO_2$ slurry ranged from 0.02 to 0.2 W/m-K, and the mixture viscosity was larger than that of pure $CO_2$ by 1.9~2.7 times. The heat capacity of $CO_2$ slurry ranged from 63 to 68% of that for pure $CO_2$. The predicted heat transfer coefficient of $CO_2$ slurry was 6 times higher than that of pure $CO_2$. In the separate model, the estimated pressure drop increased with an increase of $CO_2$-hydrate mole fraction, and was 60% of that of pure $CO_2$.

• 한국데이터정보과학회:학술대회논문집
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• 2005.04a
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• pp.83-126
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• 2005

Single-index models have found applications in econometrics and biometrics, where multidimensional regression models are often encountered. Here we propose a nonparametric estimation approach that combines wavelet methods for non-equispaced designs with Bayesian models. We consider a wavelet series expansion of the unknown regression function and set prior distributions for the wavelet coefficients and the other model parameters. To ensure model identifiability, the direction parameter is represented via its polar coordinates. We employ ad hoc hierarchical mixture priors that perform shrinkage on wavelet coefficients and use Markov chain Monte Carlo methods for a posteriori inference. We investigate an independence-type Metropolis-Hastings algorithm to produce samples for the direction parameter. Our method leads to simultaneous estimates of the link function and of the index parameters. We present results on both simulated and real data, where we look at comparisons with other methods.