• 제목/요약/키워드: random intercept

검색결과 38건 처리시간 0.03초

유도탄의 실시간 표적 재지정을 위한 랜덤 포레스트 기법과 시뮬레이션 기반 효과 분석 (Random Forest Method and Simulation-based Effect Analysis for Real-time Target Re-designation in Missile Flight)

  • 이한강;장재연;안재민;김창욱
    • 한국시뮬레이션학회논문지
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    • 제27권2호
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    • pp.35-48
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    • 2018
  • 북한의 전술탄도미사일(TBM, tactical ballistic missile)에 대한 방공 분야 연구는 빠른 속도로 변화하는 전장 환경을 고려해야 한다. 아군 유도탄의 표적 재지정 연구는 동적인 전장에 대한 대응뿐만 아니라 아군 방어 자산의 효과적인 운용을 가능하게 한다. 현재까지 진행된 연구는 의사 결정 과정에서 중요한 역할을 하는 TBM의 명중 확률이 고정된 값이기 때문에 실시간 전장 상황을 대변하지 못한다. 따라서 본 연구는 실시간 전장 환경을 고려한 명중 확률을 기반으로 의사 결정을 내리는 표적 재지정 알고리즘을 제안한다. 제안 방법론은 랜덤 포레스트와 무빙윈도우(moving window) 기법을 사용하여 현재 TBM의 위치 및 속도 정보로 TBM의 예상 궤적을 예측하는 궤적 예측 모형을 포함한다. 예상 명중 확률은 궤적 예측 모형과 유도탄의 시뮬레이터를 통해서 계산할 수 있으며, 계산된 명중 확률은 유도탄에 대한 표적 재지정 알고리즘의 의사결정 기준이 된다. 실험에서는 TBM 궤적 예측 모형에 사용한 방법론의 타당성이 검증되었으며, 표적 재지정 의사 결정 과정에서 제안된 모델을 통해 명중 확률을 사용하는 것의 우수성이 확인되었다.

Estimation of Covariance Functions for Growth of Angora Goats

  • Liu, Wenzhong;Zhang, Yuan;Zhou, Zhongxiao
    • Asian-Australasian Journal of Animal Sciences
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    • 제22권7호
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    • pp.931-936
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    • 2009
  • Body weights of 862 Angora goats between birth and 36 months of age, recorded on a semiyearly basis from 1988 to 2000, were used to estimate genetic, permanent environmental and phenotypic covariance functions. These functions were estimated by fitting a random regression model with 6th order polynomial for direct additive genetic and animal permanent environmental effects and 4th and 5th order polynomial for maternal genetic and permanent environmental effects, respectively. A phenotypic covariance function was estimated by modelling overall animal and maternal effects. The results showed that the most variable coefficient was the intercept for both direct and maternal additive genetic effects. The direct additive genetic (co)variances increased with age and reached a maximum at about 30 months, whereas the maternal additive genetic (co)variances increased rapidly from birth and reached a maximum at weaning, and then decreased with age. Animal permanent environmental (co)variances increased with age from birth to 30 months with lower rate before 12 months and higher rate between 12 and 30 months. Maternal permanent environmental (co)variances changed little before 6 months but then increased slowly and reached a maximum at about 30 months. These results suggested that the contribution of maternal additive genetic and permanent environmental effects to growth variation differed from those of direct additive genetic and animal permanent environmental effects not only in expression time, but also in action magnitude. The phenotypic (co)variance estimates increased with age from birth to 36 months of age.

인터넷기반의 데이터베이스내의 회원들 관리를 위한 mailing list 에이젼트에 관한 연구 (A Study on Mailing list Agent for Paid member in Internet based Database System)

  • 김석수
    • 디지털콘텐츠학회 논문지
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    • 제3권1호
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    • pp.123-130
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    • 2002
  • 본 mailing list system은 데이터 베이스 접근 시 데이터 베이스 ODBC설정정보를 따로 저장하지 않고 mailing list 만을 목적으로 E-mail만 발송하기 때문에 데이터베이스의 무단사용을 막게 되어 있으며, 홈페이지의 회원으로 가입한 가입자의 신상 중 E-mail 주소를 데이터 베이스로부터 읽어들여 전체 또는 어느 특정 층에 해당하는 사람들에게 E-mail을 보낸다.

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Statistical notes for clinical researchers: simple linear regression 2 - evaluation of regression line

  • Kim, Hae-Young
    • Restorative Dentistry and Endodontics
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    • 제43권3호
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    • pp.34.1-34.5
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    • 2018
  • In the previous section, we established a simple linear regression line by finding the slope and intercept using the least square method as: ${\hat{Y}}=30.79+0.71X$. Finding the regression line was a mathematical procedure. After that we need to evaluate the usefulness or effectiveness of the regression line, whether the regression model helps explain the variability of the dependent variable. Also, statistical inference of the regression line is required to make a conclusion at the population level, because practically, we work with a sample, which is a small part of population. Basic assumption of sampling method is simple random sampling.

건물과 지역요인을 고려한 서울시 건물에너지 소비 실증분석 (An Empirical Analysis of Building Energy Consumption Considering Building and Local Factors in Seoul)

  • 이수진;김기중;이승일
    • 국토계획
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    • 제54권5호
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    • pp.129-138
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    • 2019
  • This study aims to empirically examine the relationship between building energy consumption and building and local factors in Seoul. Building energy issue is an important topic for low carbon and eco-friendly city development. Building physical, socio-economic and environmental factors effect to increasing or decreasing energy consumption. However, there are different characteristic in each area, and this kind of variable has a hierarchical structure. The multi-level model was used to consider the hierarchical structure of the variables. In this study, a multi-level model was applied to confirm the difference between areas. Spatial area is Seoul, Korea and the temporal scope is August, summer season. As the result, in Model 1 (Null Model), ICC is 0.817. This shows that the energy consumption differs by 8.174% due to factors at the Dong level. Model 2 (Random Intercept Model) suggests that building's physical factors and Average age, Household size and Land price in Dong level have significant effects on Building energy consumption. In Model 3 (Random Coefficient Model), random effect variables have intercepts and slopes to vary across groups. This study provides a perspective for policy makers that the building energy reduction policies to be applied for buildings should be differently applied on area. Furthermore, not only physical factors but also socio-economic and environmental factors are important when making energy reduction policy.

A New Physical Layer Transmission Scheme for LPI and High Throughput in the Cooperative SC-FDMA System

  • Li, Yingshan;Wu, Chao;Sun, Dongyan;Xia, Junli;Ryu, Heung-Gyoon
    • Journal of Communications and Networks
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    • 제15권5호
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    • pp.457-463
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    • 2013
  • In recent days, cooperative diversity and communication security become important research issues for wireless communications. In this paper, to achieve low probability of interception (LPI) and high throughput in the cooperative single-carrier frequency division multiple access (SC-FDMA) system, a new physical layer transmission scheme is proposed, where a new encryption algorithm is applied and adaptive modulation is further considered based on channel state information (CSI). By doing so, neither relay node nor eavesdropper can intercept the information signals transmitted from user terminal (UT). Simulation results show above new physical layer transmission scheme brings in high transmission safety and secrecy rate. Furthermore, by applying adaptive modulation and coding (AMC) technique according to CSI, transmission throughput can be increased significantly. Additionally, low peak-to-average power ratio (PAPR) characteristic can still be remained due to the uniform distribution of random coefficients used for encryption algorithm.

설명변수가 랜덤인 성형 프로파일 연구 (Linear profile monitoring with random covariate)

  • 김다은;이성임;임요한
    • 응용통계연구
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    • 제35권3호
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    • pp.335-346
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    • 2022
  • 통계적 공정관리에서 프로파일 관리도란 다수의 품질 특성치 간 함수관계의 변화를 탐지하는 것을 말한다. 두 변수 간 선형의 관계가 있는 경우, 선형 프로파일을 가정하고 절편과 기울기가 일정한지 모니터링한다. 이때 선형 프로파일에 관한 대부분의 기존 연구에서는 모든 프로파일에서 설명변수의 관측치가 동일하다고 가정한다. 그러나 프로파일마다 설명변수의 값이 랜덤하게 관측되는 경우도 존재한다. 본 논문에서는 단순 선형 프로파일 모니터링에서 설명변수가 프로파일마다 랜덤하게 관측된다는 가정하에 기존의 방법을 확장 적용하고자 한다. 모의실험을 통해 제안한 방법의 탐지 성능을 확인하고 네트워크 침입 탐지 알고리즘 성능을 비교하기 위한 NSL-KDD 데이터를 이용하여 제안된 침입 탐지 결과를 비교해 보았다.

Fish Purchasing Behavior and Implications for Promoting Sustainable Consumption: A Malaysian Case

  • Ee Von GOH;Susan AZAM-ALI;Fiona MCCULLOUGH
    • Asian Journal of Business Environment
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    • 제13권2호
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    • pp.29-37
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    • 2023
  • Purpose: Motivated by the fact that Malaysians fish consumption patterns and preferences have raised sustainability concerns, this study aims to understand the key entry points to promote sustainable consumption and increased uptake of sustainably sourced fish among Malaysian consumers. This is achieved by exploring the individual determinants of Malaysian consumers' fish purchasing behaviors and their subjective and objective knowledge of fish. Research design, data, and methodology: A survey was conducted using interviewled questionnaire on 250 consumers in selected Malaysian populations recruited via street-intercept random sampling. Results: Findings confirmed the homogeneous societal culture of fish consumption amongst Malaysians. Females and consumers with advanced degree are found to be potentially effective primary targets of sustainable consumption interventions. Future interventions should consider the solutions to the low health and sustainability literacies among Malaysian consumers, and limited availability, accessibility, and affordability of sustainable options in Malaysia. Conclusion: The study findings provide new insights for the multisectoral stakeholders in the region working on promoting sustainable fish consumption and sustainable fisheries in general.

Bayesian Conway-Maxwell-Poisson (CMP) regression for longitudinal count data

  • Morshed Alam ;Yeongjin Gwon ;Jane Meza
    • Communications for Statistical Applications and Methods
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    • 제30권3호
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    • pp.291-309
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    • 2023
  • Longitudinal count data has been widely collected in biomedical research, public health, and clinical trials. These repeated measurements over time on the same subjects need to account for an appropriate dependency. The Poisson regression model is the first choice to model the expected count of interest, however, this may not be an appropriate when data exhibit over-dispersion or under-dispersion. Recently, Conway-Maxwell-Poisson (CMP) distribution is popularly used as the distribution offers a flexibility to capture a wide range of dispersion in the data. In this article, we propose a Bayesian CMP regression model to accommodate over and under-dispersion in modeling longitudinal count data. Specifically, we develop a regression model with random intercept and slope to capture subject heterogeneity and estimate covariate effects to be different across subjects. We implement a Bayesian computation via Hamiltonian MCMC (HMCMC) algorithm for posterior sampling. We then compute Bayesian model assessment measures for model comparison. Simulation studies are conducted to assess the accuracy and effectiveness of our methodology. The usefulness of the proposed methodology is demonstrated by a well-known example of epilepsy data.

무인기의 SEAD 임무 수행을 위한 임무 경로 생성 및 효과도 산출 기법 연구 (A Study on the Techniques of Path Planning and Measure of Effectiveness for the SEAD Mission of an UAV)

  • 우지원;박상윤;남경래;고정환;김재경
    • 한국항행학회논문지
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    • 제26권5호
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    • pp.304-311
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    • 2022
  • 적 방공망 제압 임무는 현대전에서 전략적으로 중요한 임무이지만 적 방공자산에 직접적으로 노출될 위험이 높아 위험 부담이 크다. 따라서, 무인기를 활용하여 임무를 수행하는 것이 하나의 대안으로 제시된다. 본 논문에서는 무인기의 적 방공망 제압 임무 수행을 위한 경로 생성 기법과 생성된 경로에 대한 임무 효과도 산출 기법을 제안한다. 먼저, RRT 기반의 경로 탐색 알고리즘을 기반으로 적의 단거리 대공 위협을 고려할 수 있는 저공 침투/이탈 비행 경로 기법을 다룬다. 또한, 최단의 경로이면서 동시에 적의 단거리 대공 위협을 최대한 회피하는 표적 타격 경로를 생성하기 위해 Dubins 경로 기반의 타격 경로 생성 기법이 사용된다. 이를 통해 생성된 침투/타격/이탈 경로를 순서에 따라 통합한다. 통합된 경로를 기반으로 연료소모량, 무인기의 생존 확률, 임무 수행 소요 시간, 그리고 표적 파괴 확률로 이루어진 임무 효과도를 산출한다. 마지막으로, 제안된 적 방공망 제압 임무 경로 생성 기법 및 임무 효과도 산출 기법을 가상 시나리오를 통해 검증한다.