• Title/Summary/Keyword: high order statistics

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A Study for Establishment to the hierarchy of Housing Values (주거가치 체계 정립을 위한 연구)

  • 최목화
    • Journal of the Korean Home Economics Association
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    • v.25 no.4
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    • pp.85-97
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    • 1987
  • The purpose of this study was to establish the hierarchy of housing values. Housing values were hygienic, safety, convenience of near environment, social affiliation oriented, self-actualization, aesthetic, and prestige. A final instrument was developed through two stage pilot surveys. The respondents were 1292 homemakers of middle and high economic class in Seoul and Daejeon, selected through stratified randon sampling technique. Data were collected during March and April 1986, and analyzed using SPSS and SAS computer packages. The statistics used were frequency, percentage, Guttman's reproducibility coefficient. The major finding were as follows; The hierachy of housing values was established with Guttman's coefficient of reproducibility. 94. Those were hygienic value, safety value, convenience of near environment value, aesthetic value, social affiliation oriented value, self-actualization value, prestige value in order.

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Lagrangian Investigation of Turbulent Channel Flow (I) - An Assessment of Particle Tracking Algorithms - (난류채널유동의 라그란지안 해석 (I)- 입자추적 알고리듬 평가 -)

  • Choi, Jung-Il;Lee, Chang-Hoon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.7
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    • pp.859-866
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    • 2003
  • The Lagrangian dispserion of fluid particles in inhomogeneous turbulence is investigated by a direct numerical simulation of turbulent channel flow. Fluid particle velocity and acceleration along a particle trajectory are computed by employing several interpolation schemes such as linear interpolation, high-order Lagrange polynomial interpolation and the Hermite interpolation schemes. The performances of the schemes are evaluated through comparison of errors in computed particle positions, velocities and accelerations against spectral interpolation. Adopting the four-point Hermite interpolation in the homogeneous directions and Chebyshev polynomials in the wall-normal direction appears to produce most reliable Lagrangian statistics including acceleration correlations with a reasonable amount of computational overhead.

Symptoms of Self-excited Combustion Oscillation and their Detection

  • Yang, Young-Joon;Akamatsu, Fumiteru;Katsuki, Masashi;Bae, Suk-Tae;Kim, Si-Pom
    • Journal of Mechanical Science and Technology
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    • v.18 no.10
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    • pp.1859-1868
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    • 2004
  • Monitoring of OH chemiluminescence through an optical fiber was demonstrated to be a useful method in detecting self-excited combustion oscillations. OH chemiluminescence intensity detected by the optical fiber showed mostly excellent agreement with those obtained by high speed CCD camera measurements when combustion oscillations were strong. Symptoms of self-excited combustion oscillation were also studied in order to predict the onset of combustion oscillation before it proceeded to a catastrophic failure. For the purpose, we have found and proposed unique measures to tell the onset of self-excited combustion oscillations based on the careful statistics of fluctuating properties in flames, such as pressure or emission of OH radicals.

UNDER-DENSITY REGIONS AND THE PRIMORDIAL DENSITY FIELD

  • KIM MINSUN;PARK CHANGBOM
    • Journal of The Korean Astronomical Society
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    • v.31 no.2
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    • pp.109-115
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    • 1998
  • We show that the low density regions of the matter distribution preserve the properties of the primordial density field better than the high density regions. We have performed a cosmological N-body simulation of large-scale structure formation in the standard CDM cosmology, and studied the evolution of statistics of under-density and over-density regions separately. The rank-order of the under-density regions is closer to the original one compared to that of the over-density regions. The under-density peaks (or voids) has moved less than over-density peaks (or dense clusters of galaxies) from their initial positions. Therefore, the under-density regions are more useful than the over-density regions in the study of the statistical property of the primordial density field.

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Modified Sign-Godard Blind Equalizer Operating on Dual Mode (이중모드로 동작하는 개선된 Sign-Godard 자력 등화기)

  • Cho, Hyun-Don;Jang, Tae-Jeong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.9C
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    • pp.1235-1243
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    • 2004
  • In this paper, a new blind equalizer algorithm is proposed which operates on dual mode and combines the benefits of both the Sign-Godard algorithm and the radius-directed algorithm The proposed algorithm has both the properties of good initial convergence of the Sign-Godard algorithm and low residual errors after convergence of the radius-directed algorith High order statistics are used for blind phase recovery and gor avoiding local minima. Simulation results show that the new algorithm has not only faster convergence rated but also lower residual errors than those of the conventional algorithms.

Workload Distribution and Performance Analysis Simulation for a Distributed Server Cluster System (분산 서버 클러스터 시스템의 부하 분산 및 성능 분석 시뮬레이션)

  • 최은미;이원규
    • Journal of the Korea Society for Simulation
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    • v.12 no.4
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    • pp.103-111
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    • 2003
  • A distributed sewer cluster system is a cost-effective system to provide a service application for clients with reliable, scalable, available, and fault-tolerant features. In order to provide high quality services, it is necessary to evaluate service performances, tune the server system, and analyze performances. In this paper, we propose a simulator to generate workloads based on statistic configuration according to estimated application traffics, apply workload scheduling algorithms, and evaluate the simulation results. We introduce the simulator design modelling and architecture. By using flexible parameters, the simulator is able to generate various patterns of workloads with different statistics, and configure system environments such as the number of server nodes, system resources considered, and their capacities. With this simulator, we introduce two scenarios: one is to find appropriate thresholds for the best performance of cluster system, and the other is to find the suitable scheduling algorithm for workload characteristics of service applications.

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software packages for survey data analysis (조사 데이터 분석용 소프트웨어 패키지)

  • 성내경
    • Survey Research
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    • v.1 no.1
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    • pp.109-123
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    • 2000
  • In order to make statistically valid inferences for survey data based on complex probability sample designs, survey researchers must incorporate the sample design in the data analysis If this in not the case the variance estimates of survey statistics derived under the usual simple random sampling assumptions from an infinite population generally underestimate the true variance, which results in high Type l error level. In this article we introduce new software packages dedicated to analyze complex survey data In particular, we summarize analysis capabilities on SUDAAN Version 7.5 and SAS Version 8.

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Multiresolution Independent Component Analysis for Iris Identification

  • Noh, Seung-In;Kwanghuk Pae;Lee, Chulhan;Kim, Jaihie
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1674-1677
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    • 2002
  • In this paper, the new method to extract the features of iris signals is proposed; Multiresolution ICA (M-ICA) provides good properties to represent signals with time-frequency. The conventional methods were to use the technique of filter bank analysis, while ICA is unsupervised learning algorithm using high-order statistics. M-ICA could make use of strengths of learn- ing method and multiresolution. Also, we performed comparative studies of different feature extraction techniques applied to personal identification using iris pat- tern. To measure goodness of methods, we use Fisher’s discriminant ratio to quantify the class-separability of features generated by various techniques.

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A Study on the Enhancement of the Quality of Pusan Port Traffic Management Service (부산항 해상교통관제 서비스의 품질개선에 관한 연구)

  • 이은방;윤정수
    • Proceedings of KOSOMES biannual meeting
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    • 2001.05a
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    • pp.105-133
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    • 2001
  • World trade has been increasing continuously in total volume, on the other hand, environmental protection on sea and conservation of fishery resources has been rising up the major issue. All of the world are pushing their efforts two major purposes to the full, one is taking competitive place in marine transportation throughout the world and another Is environment protection. Pusan Port as world leading Port put its all effort in bring more ocean going vessels and securing their traffic route by providing them more information related marine traffics through PTMS in port. During two years of operation, statistics of marine traffic accidents showed that many dynamic casualties such as collisions, groundings, and rammings has been decreased. However, due to increasing cargo volume, limited water area and unpredictable weather condition, potential risks still exist high. In this paper, in order to maximize the efficiency of PTMS and reduce various risks in the future, we examine risk factors over operational results and experience, and propose reasonable operational methods of PTMS.

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The Influence of Emotional Labor at Seoul Management Operations Center on Job Performance : Focusing on the Mediating Effect of Social Support (서울종합방재센터 종합상황실 소방공무원의 감정노동이 조직몰입에 미치는 영향 - 사회적 지원의 매개효과를 중심으로 -)

  • Park, Chan Seok;Kim, Jin Keun
    • Journal of the Korea Safety Management & Science
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    • v.17 no.2
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    • pp.13-25
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    • 2015
  • In recent years, the surroundings of Fire have rapidly changed and citizens need for Fire have been demanding very high. Under these situations, in order for satisfaction to all these demands, Seoul Emergency Operations Center have made improvements as the core fire operational center in Korea. However, There have been so many problems happening in the middle of receiving calls from malice citizens of Seoul. The purpose of this study is to scrutinize current operations focused on fire fighters in Seoul Emergency Operations Center and to cope with how to overcome these problem by using AMOS 21 & SPSS Statistics 21. The result of this study presents that how we can find to be Seoul Emergency Operations Center running well. And This study is applied to seoul fire policies or helped to setting them up.