• 한국표면공학회지
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• 제54권5호
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• pp.278-284
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• 2021

Corrosion of steel plate is common phenomenon which results in the gradual destruction caused by a wide variety of environments. Corrosion monitoring is the tracking of the degradation progress for a long period of time. Corrosion on steel plate appears as a discoloration and any irregularities on the surface. In this study, we developed a quantitative evaluation method of the rust formed on steel plate by using k-means clustering from the corroded area in a given image. The k-means clustering for automated corrosion detection was based on the GrabCut segmentation and Gaussian mixture model(GMM). Image color of the corroded surface at cut-edge area was analyzed quantitatively based on HSV(Hue, Saturation, Value) color space.

• 천문학회보
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• 제41권2호
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• pp.60.3-61
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• 2016

Galaxy morphology involves complex effects from both secular and non-secular evolution of galaxies. Although it is a final product of galaxy evolution, it gives a clue to the processes that the a galaxy has gone through. Galaxy clusters are the sites where the most massive galaxies are found, and thus the most dramatic merger histories are embedded. Our deep imaging program (${\mu}{\sim}28\;mag\;arcsec^{-2}$), KASI-Yonsei Deep Imaging Survey for Clusters (KYDISC), targets 14 Abell clusters at z = 0.016 - 0.14 using IMACS/Magellan telescope and MegaCam/CFHT to investigate cluster galaxies especially on low surface brightness features related to galaxy interactions. We visually classify galaxy morphology based on criteria related to secular or merger related evolution and find that the morphological mixture of galaxies varies considerably from cluster to cluster. Moreover it depends on the characteristics (e.g. cluster mass) of cluster itself which implies that environmental effects in cluster scale is also an important factor to the evolution of galaxies together with intrinsic (secular) and galaxy merger. Our deep imaging survey for morphological inspection of cluster galaxies with low surface brightness is expected to be a useful basis to understand the nature of cluster galaxies and their internal/external evolutionary path.

• 한국디지털건축인테리어학회논문집
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• 제9권2호
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• pp.35-43
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• 2009

The purpose of this study is to know the way of practical space use and user behavior pattern at the livingroom of city apartment that is the representative residential space of modern citizen. The way of study is to compare the livingroom of model house with actual condition of livingroom, through this way, we will know that livingroom is in use as the original concept of design or not. From the research which sees consequently (1) Most of the current model houses show common kind of livingroom by using typical style and arrangement of furniture (TV, couch, table, and decorations such as pictures or other artworks). (2) Actual condition of livingroom is different from model house in furniture arrangement and in using space which is set depending on the residents' preferences and characteristics.(computer, desk, exercising equipments, and instruments etc.) (3) The actual condition of livingroom shows the various behavior pattern of space use as the actual condition of livingroom is a mixture of typical kind of livingroom and the livingroom that reflects the characteristics of residents'.

• ETRI Journal
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• 제35권1호
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• pp.100-108
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• 2013

In this paper, a feature extraction (FE) method is proposed that is comparable to the traditional FE methods used in automatic speech recognition systems. Unlike the conventional spectral-based FE methods, the proposed method evaluates the similarities between an embedded speech signal and a set of predefined speech attractor models in the reconstructed phase space (RPS) domain. In the first step, a set of Gaussian mixture models is trained to represent the speech attractors in the RPS. Next, for a new input speech frame, a posterior-probability-based feature vector is evaluated, which represents the similarity between the embedded frame and the learned speech attractors. We conduct experiments for a speech recognition task utilizing a toolkit based on hidden Markov models, over FARSDAT, a well-known Persian speech corpus. Through the proposed FE method, we gain 3.11% absolute phoneme error rate improvement in comparison to the baseline system, which exploits the mel-frequency cepstral coefficient FE method.

• Communications for Statistical Applications and Methods
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• 제19권1호
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• pp.157-168
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• 2012

The EM algorithm is the most important tool to obtain the maximum likelihood estimator in finite mixture models due to its stability and simplicity. However, its convergence rate is often slow because the conventional EM algorithm is based on a large missing data space. Several techniques have been proposed in the literature to reduce the missing data space. In this paper, we review existing methods and propose a new EM algorithm for Gaussian mixtures, which reduces the missing data space while preserving the stability of the conventional EM algorithm. The performance of the proposed method is evaluated with other existing methods via simulation studies.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2007년도 학술대회 1부
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• pp.293-297
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• 2007

Human Computer Interaction 기술을 구체화 시키기 위한 Intelligent Responsive Space의 개발에 있어서 음성정보는 여러 가지로 유용하게 활용될 수 있다. 음성신호로부터 얻을 수 있는 다양한 정보 중의 하나가 화자인식을 이용한 화자의 신원식별이다. 이 논문에서는 화자인식 인식이 어려운 환경에서도 음성 신호로부터 추출한 특성벡터들을 선택적으로 사용함으로써 화자인식 성능을 높일 수 있는 새로운 방법을 제안하려 한다. 화자를 인식하는데 있어서 인식오류를 발생시킬 가능성이 높은 특성벡터들을 인식을 위한 판단의 대상에서 배제시킴으로써 성능을 향상시킬 수 있다. 실험결과에 의하면 0.25초에서2초 길이의 짧은 음성만으로도 기존의 방법에 비해 20에서 51%의 상대적 성능 향상을 보였다. 새롭게 제안된 방법을 적용하면 기존의 방법들에 비해 세밀하면서도 정확하게 연속적으로 화자들을 인식할 수 있게 된다.

• 한국농공학회논문집
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• 제62권4호
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• pp.23-31
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• 2020

Recently, meteorological disasters have been increasing by climate change, excessive rainfall, and landslide. The purpose is to develop new fabric concrete that can prevent and recover from damages because some of areas are vulnerable to meteorological disaster. Specifically, this technology can minimize time and space constraint when repairing the concrete structure and installing a formwork. The structure of fabric concrete is a mixture of fabric concrete and a high-speed hardened cement, Silica sand, wollastonite mineral fiber, fabric material and waterproof PVC fabric. In this study, the ratio of mechanical properties and durability of the fabric concrete mixture was evaluated by deriving the binder: silica sand mix ratio of the fabric concrete mixture and substituting part of the cement amount with wollastonite mineral fiber. Best binder in performance evaluation: Silica sand mix ratio is 6: 4 and the target mechanical performance and durability are the best when over 15% wollastonite binder is replaced by silicate mineral fiber.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1326-1328
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• 2003

An elliptical basis function (EBF) network is proposed in this study for the classification of remotely sensed images. Though similar in structure, the EBF network differs from the well-known radial basis function (RBF) network by incorporating full covariance matrices and uses the expectation-maximization (EM) algorithm to estimate the basis functions. Since remotely sensed data often take on mixture -density distributions in the feature space, the proposed network not only possesses the advantage of the RBF mechanism but also utilizes the EM algorithm to compute the maximum likelihood estimates of the mean vectors and covariance matrices of a Gaussian mixture distribution in the training phase. Experimental results show that the EM-based EBF network is faster in training, more accurate, and simpler in structure.

• 한국가스학회지
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• 제7권4호
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• pp.14-19
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• 2003

일반적으로 발생하는 사고중의 가스폭발사고는 일정한 상태로의 혼합과정보다는 불균일하게 이루어진 상태로 폭발이 발생하고 있다. 본 연구에서는 불균일 상태에서의 불균일 농도에 의한 폭발현상을 실제 실내의 축소형으로 폭발통을 제작, 모형화하여 여러현상을 재현함으로서 실제 사고시의 폭발현상을 예측할 수 있었다. 그 결과, 어떤 공간에서 가스가 누출될 경우 내부의 가스의 혼합정도는 누출구의 크기 및 누출속도에 따라 영향을 받으며, 불균일 정도가 클수록 폭발압력 및 압력상승속도는 낮아지고 폭발압력은 감소하지만 화염의 체류시간이 증가하여 폭발화염의 복사열에 의한 폭발 후에는 화재의 위험성이 증가함을 알 수 있었다.

• 대한음성학회지:말소리
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• 제52호
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• pp.133-144
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• 2004

The quality of narrowband speech can be enhanced by the bandwidth extension technology. This paper proposes a mixed excitation and an energy compensation method based on Gaussian Mixture Model (GMM). First, we employ the mixed excitation model having both periodic and aperiodic characteristics in frequency domain. We use a filter bank to extract the periodicity features from the filtered signals and model them based on GMM to estimate the mixed excitation. Second, we separate the acoustic space into the voiced and unvoiced parts of speech to compensate for the energy difference between narrowband speech and reconstructed highband, or lowband speech, more accurately. Objective and subjective evaluations show that the quality of wideband speech reconstructed by the proposed method is superior to that by the conventional bandwidth extension method.