• Title/Summary/Keyword: correlation feature analysis

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Topology Optimization based on Monte Carlo Analysis (몬테카를로 해석 기반 확률적 위상최적화)

  • Kim, Dae Young;Noh, Hyuk Chun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.30 no.2
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    • pp.153-158
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    • 2017
  • In this paper, we take into account topology optimization problems considering spatial randomness in the material property of elastic modulus. Based on 88 lines MATLAB Code, Monte Carlo analysis has been performed for MBB(messerschmidt-$b{\ddot{o}}lkow$-blohm) model using 5,000 random sample fields which are generated by using the spectral representation scheme. The random elastic modulus is assumed to be Gaussian in the spatial domain of the structure. The variability of the volume fraction of the material, which affects the optimum topology of the given problem, is given in terms of correlation distance of the random material. When the correlation distance is small, the randomness in the topology is high and vice versa. As the correlation distance increases, the variability of the volume fraction of the material decreases, which comply with the feature of the linear static analysis. As a consequence, it is suggested that the randomness in the material property is need to be considered in the topology optimization.

A Study on Status, Purchase Factors and Satisfaction of Clothes through Internet Shopping Mall (인터넷 쇼핑몰을 통(通)한 의류제품(衣類製品)의 구매실태(購買實態), 구매요인(購買要因) 및 구매만족(購買滿足)에 관(關)한 연구(硏究))

  • Lee, Yeon-Sei;Yoo, Tai-Soon;Kim, Young-Ran
    • Journal of Fashion Business
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    • v.8 no.5
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    • pp.20-30
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    • 2004
  • The subjects of the study were randomly male and female college students in Seoul. The 123 subjects had experience of purchasing clothes from Internet shopping mall. To analyze SPSS(ver 10.0) was used $X^2$, ANOVA, Correlation analysis, Multiple regression and Cronbach $\alpha$ were performed for verification. For significance judgement, .05 was used, which is commonly used in social science. The result of this study were most of them purchased closes once or twice a year through Internet shopping mall. The most popular item was T-shirts or sweater and money spent per visit was less than 100,000 won. Those who have used Internet for a longer period tend to purchase more items tend to purchase more frequently. Subjective satisfaction which is a sub factor of the product purchase and product purchase times have significant correlation and total purchase amount and the sub factors of purchase satisfaction. There is significant correlation among product information provision, which is a sub factor of purchase feature and product information provision, marketability, convenience of delivery, additional features and subjective satisfaction which are sub factors of purchase satisfaction. Clothing purchase factors influencing on subjective satisfaction are product information provision and marketability and marketability is the stronger influencing feature of the two.

A Study of the Valid Model(Kernel Regression) of Main Feed-Water for Turbine Cycle (주급수 유량의 유효 모델(커널 회귀)에 대한 연구)

  • Yang, Hac-Jin;Kim, Seong-Kun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.12
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    • pp.663-670
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    • 2019
  • Corrective thermal performance analysis is required for power plants' turbine cycles to determine the performance status of the cycle and improve the economic operation of the power plant. We developed a sectional classification method for the main feed-water flow to make precise corrections for the performance analysis based on the Performance Test Code (PTC) of the American Society of Mechanical Engineers (ASME). The method was developed for the estimation of the turbine cycle performance in a classified section. The classification is based on feature identification of the correlation status of the main feed-water flow measurements. We also developed predictive algorithms for the corrected main feed-water through a Kernel Regression (KR) model for each classified feature area. The method was compared with estimation using an Artificial Neural Network (ANN). The feature classification and predictive model provided more practical and reliable methods for the corrective thermal performance analysis of a turbine cycle.

An analysis of satisfaction index on computer education of university based on Fuzzy Decision Making Method (퍼지의사결정법에 기반한 대학의 컴퓨터교육 만족도 분석)

  • Ryu, Kyung-Hyun;Hwang, Byung-Kon
    • Journal of Korea Multimedia Society
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    • v.16 no.4
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    • pp.502-509
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    • 2013
  • In Information age, The academic liberal art computer education course set up goals to promote computer literacy and develop the ability to cope with changes in information society and improve productivity and national competitiveness. In this paper, we analyze on discovering of decisive variable and satisfaction index to have a influence on computer education on university students. As a preprocessing course, the proposed method selects optimum variable using correlation based feature selection(CFS) of machine learning tool based on Java and we calculate weighted value for each variable and then, we generate the optimal variable using weighted value based on fuzzy decision making method. we proposed Fuzzy decision making method in analysis of the academic liberal art computer education satisfaction index data and checked the accuracy of the satisfaction evaluation by using recall and precision.

Water quality observation using Principal Component Analysis

  • Jeong, Jong-Chul;Yoo, Sing-Jae
    • Proceedings of the KSRS Conference
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    • 1998.09a
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    • pp.58-63
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    • 1998
  • The aim of the present study is to define and tentatively to interpret the distribution of polluted water released from Lake Sihwa into Yellow Sea using Landsat TM. Since the region is an extreme case 2 water, empirical algorithms for chlorophyll-a and suspended sediments have limitations. This work focuses on the use of multi-temporal Landsat TM. We applied PCA to detect evolution of spatial feature of polluted water after release from the lake. The PCA results were compared with in situ data, such as chlorophyll-a, suspended sediments, Secchi disk depth (SDD), surface temperature, radiance reflectance at six bands. The in situ remote sensing reflectance was analysed with PCA. On the basis of these In situ data we found good correlation between first Principal Component and Secchi disk depth ($R^2$=0.7631), although other variables did not result in such a good correlation. The problems in applying PCA techniques to multi-spectral remote sensed data are also discussed.

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Computer-Based Fluency Evaluation of English Speaking Tests for Koreans (한국인을 위한 영어 말하기 시험의 컴퓨터 기반 유창성 평가)

  • Jang, Byeong-Yong;Kwon, Oh-Wook
    • Phonetics and Speech Sciences
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    • v.6 no.2
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    • pp.9-20
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    • 2014
  • In this paper, we propose an automatic fluency evaluation algorithm for English speaking tests. In the proposed algorithm, acoustic features are extracted from an input spoken utterance and then fluency score is computed by using support vector regression (SVR). We estimate the parameters of feature modeling and SVR using the speech signals and the corresponding scores by human raters. From the correlation analysis results, it is shown that speech rate, articulation rate, and mean length of runs are best for fluency evaluation. Experimental results show that the correlation between the human score and the SVR score is 0.87 for 3 speaking tests, which suggests the possibility of the proposed algorithm as a secondary fluency evaluation tool.

Correlation Analysis of Feature Space Data in End-to-end Image Compression Network (종단간 인공신경망 기반 이미지 압축 기술의 피쳐 공간 상관관계 분석)

  • Lee, Jooyoung;Jeong, Se-Yoon;Choi, Jin Soo
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2020.11a
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    • pp.151-154
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    • 2020
  • 뉴럴넷 기술이 발전과 힘께 다양한 분야에서 획기적인 성능 향상이 이루어지고 있다. 이미지 압축 분야에서도 기존의 전통적인 툴 제인 구조의 압축 방식에서 벗어나 종단간(end-to-end) 뉴렬넷 기반의 이미지 압축 기술에 대한 연구가 활발히 이루어지고 있다. 특히 최근 네트워크를 통해 변환된 피쳐 데이터의 엔트로피를 최소화하는 방식에 대한 연구가 활발히 이루어지고 있으며, 이에 기반한 최근의 연구는 VVC 화면 내 코딩 기술보다 우수한 코딩 효율성을 제공하고 있다. 그러나 변환된 피쳐 데이터에 대한 특성 분석은 부족한 실정이며, 이에 본 논문에서는 엔트로피 최소화 기반 종단간 이미지 압축 네트워크의 피쳐 공간 데이터에 대한 공간적 (spatial) 상관관계와 채널간(inter-channel) 상관관계(correlation)를 분석하고, 나아가 최근 제안된 종단간 이미지 압축 네트워크의 문맥 기반 예측 기능을 통해 잔존하는 데이터 중복성이 효과적으로 제거됨을 보인다.

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Correlation between mergers and AGN activity : a case study with MARK 478

  • Hong, Ju-Eun;Im, Myung-Shin
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.34.1-34.1
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    • 2010
  • Studies suggest that activities in luminous AGNs, residing mostly in early-type galaxies, are triggered by merging. However, the observational evidence for the connection between mergers and AGN activity is not clear yet because tracer of the past merging activities such as tidal tail, shell are often too faint. To see if we can reveal the merging features with a small telescope, we observed an AGN, MARK 478, at z=0.077 with long exposure time (7550 seconds) in V filter at Maidanak observatory. Our 2-D fitting analysis shows that the host galaxy of MARK 478 has the bulge to the total luminosity ratio of 0.3. And the residual image, after subtracting point spread function (PSF), bulge and disk components, shows that the host galaxy has an arm-like feature that could be a spiral arm or a feature from minor merging. We also show that the structural parameters obtained from our 2-D fitting match well with those derived from HST image. The promising result suggests that studies of low redshift AGN host galaxies are possible with data from a small telescope. In order to allow a statistical analysis, we hope to expand our sample size in future.

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A Study on the Evaluation of Landscape Elements in Outdoor Space at University Campus (대학캠퍼스 외부공간 경관요소 평가에 관한 연구)

  • Kim, Ick-Hwan;Kim, Cheon-Il
    • The Journal of Sustainable Design and Educational Environment Research
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    • v.12 no.3
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    • pp.58-67
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    • 2013
  • This study is to analyze the satisfaction and the image evaluation of landscape elements in outdoor space by types of the university campus. The results are as follows. 1) Out of outdoor elements at university campus, planting area, resting area, access road, and water feature are recognized as major landscape elements. Among them, planting area and access roads are evaluated low in terms of satisfaction levels, therefore, improvement on these elements are required. 2) In outdoor space image evaluation, university campus has image such as 'simple', 'clear', and 'safe'. By scale of universities, both 'A' university, which is the biggest in terms of size of campus, and 'B' university, which has a medium sized campus, have a positive image. However, 'C' university, which is the smallest in terms of size of campus, has a passive and negative image. 3) 6 factors are extracted through Factor Analysis for image evaluation. All of the universities show positive image in the categories of 'clarity' and 'familiarity', however, 'B' university and 'C' university show negative image in the category of 'scale'. 4) In Correlation Analysis between landscape elements satisfaction level and image evaluation, it is showed that the group of landscape facility becomes a relation factor of overall image evaluation. As a result, the higher satisfaction level goes, the better image evaluation of overall outdoor space at university campus is.

Comparison of Maximum Phonation Time Associated with the Changes in Vocal Intensity in Patients with Unilateral Vocal Fold Palsy and Sulcus Vocalis (성대마비와 성대구증의 강도 변화에 따른 최대발성지속시간 비교)

  • Choi, Se-Jin;Choi, Hong-Shik;Kim, Jae-Ock;Choi, Yae-Lin
    • Phonetics and Speech Sciences
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    • v.4 no.1
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    • pp.125-131
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    • 2012
  • The patients with incomplete glottic closure have an important feature decreasing the maximum phonation time (MPT) because airflow rate or air leakage is greater than people without voice disorders. Also they can appear a problem in the intensity regulation. This study analyzed MPT difference based on the comfortable intensity and louder intensity and the correlation between MPT and respiration volume of unilateral vocal fold palsy (UVFP) and sulcus vocalis (SV) group. The twenty with UVFP, the 21 with SV, the 21 normal subjects measured MPT in /a/ vowel prolongation task with comfortable intensity and louder intensity and compared analysis by measuring FVC, $FEV_1$, $FEV_1/FVC$ to analyze the correlation between MPT and respiration volume. First, a comparison of MPT according to the intensity between groups is that MPT of the normal group was statistically significant long compared to the patient group in comfortable intensity, but MPT between groups was not statistically significant difference in the louder intensity. Second, an analysis of the correlation between MPT and respiration volume is that this was statistically significant correlation between MPT in comfortable intensity and MPT in louder intensity. But this did not show statistically significant correlation between intensity and respiration volume. This study can be supported the preceding study results deduced that shorting MPT of the patient group compared to the normal group was originated in the problem of laryngeal valving mechanism at the level of vocal folds rather than a problem of respiratory function. Also at the phonation by varying the intensity, the result can deduce that in the case of patient group, the length of MPT had been improved by increasing the glottal closure ratio in the louder intensity. These results can support the theoretical basis that should be applied to the clinicians by varying the intensity at the voice evaluation and voice therapy for the patients with the glottis incompetence.