• Title, Summary, Keyword: Gaussian mixture

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Skewness of Gaussian Mixture Absolute Value GARCH(1, 1) Model

  • Lee, Taewook
    • Communications for Statistical Applications and Methods
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    • v.20 no.5
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    • pp.395-404
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    • 2013
  • This paper studies the skewness of the absolute value GARCH(1, 1) models with Gaussian mixture innovations (Gaussian mixture AVGARCH(1, 1) models). The maximum estimated-likelihood estimator (MELE) employed (a two- step estimation method in order to estimate the skewness of Gaussian mixture AVGARCH(1, 1) models. Through the real data analysis, the adequacy of adopting Gaussian mixture innovations is exhibited in reflecting the skewness of two major Korean stock indices.

Precise Vehicle Localization Using Gaussian Mixture Map Based on Road Marking

  • Kim, Kyu-Won;Jee, Gyu-In
    • Journal of Positioning, Navigation, and Timing
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    • v.9 no.1
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    • pp.23-31
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    • 2020
  • It is essential to estimate the vehicle localization for an autonomous safety driving. In particular, since LIDAR provides precise scan data, many studies carried out to estimate the vehicle localization using LIDAR and pre-generated map. The road marking always exists on the road because of provides driving information. Therefore, it is often used for map information. In this paper, we propose to generate the Gaussian mixture map based on road-marking information and localization method using this map. Generally, the probability distributions map stores the single Gaussian distribution for each grid. However, single resolution probability distributions map cannot express complex shapes when grid resolution is large. In addition, when grid resolution is small, map size is bigger and process time is longer. Therefore, it is difficult to apply the road marking. On the other hand, Gaussian mixture distribution can effectively express the road marking by several probability distributions. In this paper, we generate Gaussian mixture map and perform vehicle localization using Gaussian mixture map. Localization performance is analyzed through the experimental result.

Gaussian Mixture Model Based Smoke Detection Algorithm Robust to Lights Variations (Gaussian 혼합모델 기반 조명 변화에 강건한 연기검출 알고리즘)

  • Park, Jang-Sik;Song, Jong-Kwan;Yoon, Byung-Woo
    • 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.

Optimization of Gaussian Mixture in CDHMM Training for Improved Speech Recognition

  • Lee, Seo-Gu;Kim, Sung-Gil;Kang, Sun-Mee;Ko, Han-Seok
    • Speech Sciences
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    • v.5 no.1
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    • pp.7-21
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    • 1999
  • This paper proposes an improved training procedure in speech recognition based on the continuous density of the Hidden Markov Model (CDHMM). Of the three parameters (initial state distribution probability, state transition probability, output probability density function (p.d.f.) of state) governing the CDHMM model, we focus on the third parameter and propose an efficient algorithm that determines the p.d.f. of each state. It is known that the resulting CDHMM model converges to a local maximum point of parameter estimation via the iterative Expectation Maximization procedure. Specifically, we propose two independent algorithms that can be embedded in the segmental K -means training procedure by replacing relevant key steps; the adaptation of the number of mixture Gaussian p.d.f. and the initialization using the CDHMM parameters previously estimated. The proposed adaptation algorithm searches for the optimal number of mixture Gaussian humps to ensure that the p.d.f. is consistently re-estimated, enabling the model to converge toward the global maximum point. By applying an appropriate threshold value, which measures the amount of collective changes of weighted variances, the optimized number of mixture Gaussian branch is determined. The initialization algorithm essentially exploits the CDHMM parameters previously estimated and uses them as the basis for the current initial segmentation subroutine. It captures the trend of previous training history whereas the uniform segmentation decimates it. The recognition performance of the proposed adaptation procedures along with the suggested initialization is verified to be always better than that of existing training procedure using fixed number of mixture Gaussian p.d.f.

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Linear regression under log-concave and Gaussian scale mixture errors: comparative study

  • Kim, Sunyul;Seo, Byungtae
    • Communications for Statistical Applications and Methods
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    • v.25 no.6
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    • pp.633-645
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    • 2018
  • Gaussian error distributions are a common choice in traditional regression models for the maximum likelihood (ML) method. However, this distributional assumption is often suspicious especially when the error distribution is skewed or has heavy tails. In both cases, the ML method under normality could break down or lose efficiency. In this paper, we consider the log-concave and Gaussian scale mixture distributions for error distributions. For the log-concave errors, we propose to use a smoothed maximum likelihood estimator for stable and faster computation. Based on this, we perform comparative simulation studies to see the performance of coefficient estimates under normal, Gaussian scale mixture, and log-concave errors. In addition, we also consider real data analysis using Stack loss plant data and Korean labor and income panel data.

A Study on Gaussian Mixture Synthesis for High-Performance Speech Recognition (High-Performance 음성 인식을 위한 Efficient Mixture Gaussian 합성에 관한 연구)

  • 이상복;이철희;김종교
    • Proceedings of the IEEK Conference
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    • pp.195-198
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    • 2002
  • We propose an efficient mixture Gaussian synthesis method for decision tree based state tying that produces better context-dependent models in a short period of training time. This method makes it possible to handle mixture Gaussian HMMs in decision tree based state tying algorithm, and provides higher recognition performance compared to the conventional HMM training procedure using decision tree based state tying on single Gaussian GMMs. This method also reduces the steps of HMM training procedure. We applied this method to training of PBS, and we expect to achieve a little point improvement in phoneme accuarcy and reduction in training time.

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Extraction of Infrared Target based on Gaussian Mixture Model

  • Shin, Do Kyung;Moon, Young Shik
    • IEIE Transactions on Smart Processing and Computing
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    • v.2 no.6
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    • pp.332-338
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    • 2013
  • We propose a method for target detection in Infrared images. In order to effectively detect a target region from an image with noises and clutters, spatial information of the target is first considered by analyzing pixel distributions of projections in horizontal and vertical directions. These distributions are represented as Gaussian distributions, and Gaussian Mixture Model is created from these distributions in order to find thresholding points of the target region. Through analyzing the calculated Gaussian Mixture Model, the target region is detected by eliminating various backgrounds such as noises and clutters. This is performed by using a novel thresholding method which can effectively detect the target region. As experimental results, the proposed method has achieved better performance than existing methods.

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Channel Capacity for NOMA Weak Channel User and Capacity Region for NOMA with Gaussian Mixture Interference

  • Chung, Kyuhyuk
    • Journal of IKEEE
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    • v.23 no.1
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    • pp.302-305
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    • 2019
  • Non-orthogonal multiple access (NOMA) has been considered for the fifth generation (5G) mobile networks to provide high system capacity and low latency. We calculate the channel capacity for the weak channel user in NOMA and the channel capacity region for NOMA. In this paper, Gaussian mixture channel is compared to the additive white Gaussian noise (AWGN) channel. Gaussian mixture channel is modeled when we assume the practical signal modulation for the inter user interference, such as the binary phase shift keying (BPSK) modulation. It is shown that the channel capacity with BPSK inter user interference is better than that with Gaussian inter user interference. We also show that the channel capacity region with BPSK inter user interference is larger than that with Gaussian inter user interference. As a result, NOMA could perform better in the practical environments.

(Lip Recognition Using Active Shape Model and Gaussian Mixture Model) (Active Shape 모델과 Gaussian Mixture 모델을 이용한 입술 인식)

  • 장경식;이임건
    • Journal of KIISE:Software and Applications
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    • v.30 no.5_6
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    • pp.454-460
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    • 2003
  • In this paper, we propose an efficient method for recognizing human lips. Based on Point Distribution Model, a lip shape is represented as a set of points. We calculate a lip model and the distribution of shape parameters using Principle Component Analysis and Gaussian mixture, respectively. The Expectation Maximization algorithm is used to determine the maximum likelihood parameter of Gaussian mixture. The lip contour model is derived by using the gray value changes at each point and in regions around the point and used to search the lip shape in a image. The experiments have been performed for many images, and show very encouraging result.