• Title/Summary/Keyword: variance structure

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An Optimum Radar Signal Detector using Orthogonal Projection (직교 투사를 이용한 최적 레이다 신호 검출기)

  • 김영훈;김기만;이종길;박영찬;곽영길;윤대희
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.7
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    • pp.1407-1413
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    • 1994
  • To obtain accurate target information in a radar system, clutter or interference signals must first be effectively removed for target detection. In this paper, the signal is projected onto a constrained orthogonal subspace, so that a minimum variance optimal detector is transformed into an unconstrained detector. The proposed algorithm is equivalent to the conventional optimal detector algorithm, and th algorithm structure shows that the Gram-Schmidt orthogonalization can be achieved to obtain the fast convergence. The performance of the proposed method was observed by simulation experiments.

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On the Dependence Structure of Concornitants of Order Statistics

  • Song-Ho Kim;Tae-Sung Kim
    • Journal of the Korean Statistical Society
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    • v.25 no.2
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    • pp.255-263
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    • 1996
  • Let $(X_{1j}, X_{2j}, … , X_{nj}, Y_j/)$j = 1, 2, … , n, be a sample of size n on an (m + l)-dimensional vector $(X_1, X_2, … , X_m, Y)$, m .geq. 1. If $Y_{(r)}$ denote the rth order statistic from Y, then the $X_{[r:n]}$ paired with $Y_(r)$ is termed the concomitant vector of the order statistics. The general distributions of concomitant of order statistics will be found. The mean, variance and covariance of$X_{[r:n]}$ Will be studied. Then we will apply the results to the multivariate normal variate case.e.

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Parameter Design of an ER Panel for Noise Reduction using Taguchi Method (다구찌법을 이용한 소음저감용 ER 패널의 파라미터 설계)

  • 윤영민;김재환;최승복
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.638-642
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    • 2003
  • This paper presents a parameter design of an Electrorheological(ER) panel for noise reduction using Taguchi method. Taguchi method is a robust design method that determines control parameters in the presence of noise effect. Host structure thickness, spacer thickness, base oil viscosity and the weight ratio of ER particles are chosen for the control factors. A test setup in an SAE J1400 facility is used to analyze the sound transmission loss. The sensitivity of each factor with signal-to-noise(S/N) ratio and analysis of variance are investigated. The analysis results show that the weight ratio of ER particle and base oil viscosity of the ER fluid mostly affects the noise reduction in the presence of electric field. Based on the Taguchi method, an optimal configuration was designed and comparison is made with experimental result fer the verification.

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Wind Turbine Blade Design using Design of Experiments (실험계획법을 이용한 풍력발전기용 블레이드의 설계)

  • Kang, Ki-Weon;Lee, Seung-Pyo;Chang, Se-Myong;Lee, Jang-Ho
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.422-422
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    • 2009
  • This paper describes the structural design of small wind turbine blade by using design of experiments. Blade structure consists of skin, spar and foam. The materials for skin and spar are a kind of Glass/Epoxy and form is polyurethane. It has 7 lay-ups with different ply angle. A factorial design is applied to design the ply angles considering manufacturing constraints and to investigate the safety factor which is calculated by structural analysis. In order to perform the structural analysis, the commercial software ABAQUS is used. Tsai-Wu failure criterion is chosen to compute safety factor. The determination of the significance of effects in the experiments is made through the analysis of variance. The results show that ply angle at skin affects the safety factor of wind turbine blade. And from this result, optimal ply angles of composite blade are achieved.

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A Study on the Image of Show Window Display - Based on Apparel Stores in Pusan - (쇼 윈도우 디스플레이 이미지에 관한 연구 -부산지 역 의류매장을 중심으로-)

  • 노경혜;이경희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.21 no.7
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    • pp.1109-1116
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    • 1997
  • This study was designed to investigate the image of show window displays. The specific objectives of the study are as follows; 1) Construct a semantic differential scale to evaluate the images of show window displays; 2) Identify the factor structure of the show window displays; 3) Cluster the brands according to the images of show window displays; 4) Examine how the images of show window displays differ according to the different brand clusters; and 5) Identify by brand clusters, how the different show window display images affect the purchasing desires. The following conclusions were made from this study; 1.25 pairs of adjectives for show window displays were found to include five factor dimensions (total variance 67.7%) such as evaluation, interest, hardness and softness, maturity, and modernity. 2. The brands were divided into six clusters according to the show window display images. 3. There were significant differences in the visual evaluation of the brand clusters in the show window display images. 4. There were significant differences in the show window display images that affect the Purchasing desires among the brand clusters.

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A Basic Study of the European Side Impact Characteristics of Electric Vehicle(I) (전기자동차의 유럽 측면 충돌 특성 기초 연구 (I))

  • 조용범;고정한;신효철;변준형
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.5
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    • pp.173-180
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    • 2000
  • European side impact analysis of an electric vehicle was done using robust design. Locations and section properties of some of the vehicle structure components which influence the european side impact characteristics were chosen as the main factors for the robust design. Eight factors were considered for the analysis: one with two level and seven with three level combinations comprising the L18(21$\times$37) orthogonal array. It is shown that the sensitivities of the factors and the best combination of the factors can be obtained, and that the location of the main components were as much sensitive as the section properties of those. Also it is shown that the interactions were existed between some factors.

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Fear Factors in Children with Emotional and Behavioral Problems : A Q-Methodological Approach (정서·행동 문제아가 지각하는 두려움의 유형분석 : Q 방법론적 접근)

  • Koo, Mee-Hyang
    • Korean Journal of Child Studies
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    • v.26 no.1
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    • pp.75-90
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    • 2005
  • The structure of fears was identified and measured by Q methodology. Subjects were 40 school-aged children with emotional and behavioral problems. Subjectivity of children's fears was classified into 3 types by the QUANL program. Three types occupied 52% of all variance and correlations ranged between .31 and.52. The first type is "imaginative-sensitive perception" where children are fearful about unreal and imaginative objects related to death. The second type is "rational-empirical perception" where children are concerned about the impact of fearful objects and authoritative figures based on their own personal experience. The last type is "realistic-egocentric perception" where children are fearful of possible violence, crime, and disease.

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Genetic risk factors associated with respiratory distress syndrome

  • Jo, Heui Seung
    • Clinical and Experimental Pediatrics
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    • v.57 no.4
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    • pp.157-163
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    • 2014
  • Respiratory distress syndrome (RDS) among preterm infants is typically due to a quantitative deficiency of pulmonary surfactant. Aside from the degree of prematurity, diverse environmental and genetic factors can affect the development of RDS. The variance of the risk of RDS in various races/ethnicities or monozygotic/dizygotic twins has suggested genetic influences on this disorder. So far, several specific mutations in genes encoding surfactant-associated molecules have confirmed this. Specific genetic variants contributing to the regulation of pulmonary development, its structure and function, or the inflammatory response could be candidate risk factors for the development of RDS. This review summarizes the background that suggests the genetic predisposition of RDS, the identified mutations, and candidate genetic polymorphisms of pulmonary surfactant proteins associated with RDS.

The Selection of Growth Models in Technological Forecasting

  • Oh, Hyun-Seung
    • Journal of the Korean Operations Research and Management Science Society
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    • v.16 no.1
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    • pp.120-134
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    • 1991
  • Various technological forecasting models have been proposed to represent the time pattern of technological growths. Of six such models studied, some models do significantly better than others, especially at low penetration levels, in predicting future levels of growth. Criteria for selecting an appropriate model for technological growth model are examined in this study. Two major characteristics were selected which differentiate the various models ; the skew of the curve and the underlying assumptions regarding the variance of the error structure of the model. Although the use of statistical techniques stil requires some subjective input and interpretations, this study provides some practical procedures in the selection of technological growth models and helps to reduce or control the potential source of judgmental error inconsistencies in the analyst's decision.

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