• 제목/요약/키워드: Mixed Methods

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다중프로세서 시스템에서 개선된 합성 이용율을 이용한 혼합 태스크 스케줄링 (Mixed Tasks Scheduling Using Improved Synthetic Utilization on Multiprocessor Systems)

  • 문석환
    • 한국정보통신학회논문지
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    • 제19권2호
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    • pp.351-356
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    • 2015
  • 다중프로세서 시스템에서 실시간 비주기 태스크 스케줄링 방법 중 하나인 합성 이용율 방법은 주기 태스크들을 고려하지 않고 단지 비주기 태스크들을 위한 스케줄링 방식이다. 하지만 실제로 비주기 태스크는 대부분의 경우에 주기 태스크와의 혼합된 형태로 스케줄링이 이루어지며, 주기 태스크의 스케줄링을 보장하면서 비주기 태스크의 스케줄링 가능성을 판단해야 한다. 본 논문에서는 다중프로세서 시스템에서 주기태스크와 비주기 태스크가 혼합된 태스크 집합을 개선된 합성 이용율을 이용하여 스케줄링하기 위한 방법을 제시하였으며, 기존의 비주기 서버를 이용하여 혼합 태스크 집합을 스케줄링 하는 방법보다 스케줄링 성능이 향상됨을 보였다.

4성분계 복합 산화물 촉매 이용 메탄의 부분산화에 의한 메탄올 직접 합성 (Direct Methanol Synthesis by Partial Oxidation of Methane over Four-component Mixed Oxide Catalysts)

  • 김영국;이광혁;함현식
    • 한국응용과학기술학회지
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    • 제31권3호
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    • pp.446-452
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    • 2014
  • Methanol was directly produced by the partial oxidation of methane with four-component mixed oxide catalysts. Four-component(Mo-Bi-Cr-Si) mixed oxide catalysts were prepared by the co-precipitation and sol-gel methods. The catalyst prepared by the sol-gel method showed about eleven times higher surface area than that prepared by the co-precipitation method. From the $O_2$-TPD experiment of the prepared catalysts, it was proven that there exists two types of oxygen species, and the oxygen species that participates in the partial oxidation reaction is the lattice oxygen desorbing around $750^{\circ}C$. The optimum reaction condition for methanol production was $420^{\circ}C$, 50 bar, flow rate of 115 mL/min, and $CH_4/O_2$ ratio of 10/1.5, providing methane conversion and methanol selectivity of 3.2 and 26.7%, respectively.

Modified partial least squares method implementing mixed-effect model

  • Kyunga Kim;Shin-Jae Lee;Soo-Heang Eo;HyungJun Cho;Jae Won Lee
    • Communications for Statistical Applications and Methods
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    • 제30권1호
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    • pp.65-73
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    • 2023
  • Contemporary biomedical data often involve an ill-posed problem owing to small sample size and large number of multi-collinear variables. Partial least squares (PLS) method could be a plausible alternative to an ill-conditioned ordinary least squares. However, in the case of a PLS model that includes a random-effect, how to deal with a random-effect or mixed effects remains a widely open question worth further investigation. In the present study, we propose a modified multivariate PLS method implementing mixed-effect model (PLSM). The advantage of PLSM is its versatility in handling serial longitudinal data or its ability for taking a randomeffect into account. We conduct simulations to investigate statistical properties of PLSM, and showcase its real clinical application to predict treatment outcome of esthetic surgical procedures of human faces. The proposed PLSM seemed to be particularly beneficial 1) when random-effect is conspicuous; 2) the number of predictors is relatively large compared to the sample size; 3) the multicollinearity is weak or moderate; and/or 4) the random error is considerable.

단어 유사도를 이용한 뉴스 토픽 추출 (News Topic Extraction based on Word Similarity)

  • 김동욱;이수원
    • 정보과학회 논문지
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    • 제44권11호
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    • pp.1138-1148
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    • 2017
  • 토픽 추출은 문서 집합으로부터 그 문서 집합을 대표하는 토픽을 자동 추출하는 기술이며 자연어 처리의 중요한 연구 분야이다. 대표적인 토픽 추출 방법으로는 잠재 디리클레 할당과 단어 군집화 기반 토픽 추출방법이 있다. 그러나 이러한 방법의 문제점으로는 토픽 중복 문제와 토픽 혼재 문제가 있다. 토픽 중복 문제는 특정 토픽이 여러 개의 토픽으로 추출되는 문제이며, 토픽 혼재 문제는 추출된 하나의 토픽 내에 여러 토픽이 혼재되어 있는 문제이다. 이러한 문제를 해결하기 위하여 본 연구에서는 토픽 중복 문제에 대해 강건한 잠재 디리클레 할당으로 토픽을 추출하고 단어 간 유사도를 이용하여 토픽 분리 및 토픽 병합의 단계를 거쳐 최종적으로 토픽을 보정하는 방법을 제안한다. 실험 결과 제안 방법이 잠재 디리클레 할당 방법에 비해 좋은 성능을 보였다.

민간투자사업 혼합방식(BTO+BTL)의 효율성에 관한 연구 (A Study on Efficiency of Mixed Model (BTO+BTL) for Public-Private Partnership Projects)

  • 김도일;김윤식;현창택
    • 한국건설관리학회논문집
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    • 제13권5호
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    • pp.53-63
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    • 2012
  • 우리나라의 SOC 민간투자사업은 수익형(BTO) 및 임대형(BTL) 방식을 주축으로 사회기반시설을 조기에 효율적으로 공급함으로써 국민의 편익증대 및 정부의 탄력적인 재정운용에 기여하였다. 하지만, 최소운영수입보장(MRG) 제도의 폐지와 최근 국제적인 금융위기 등 사업 환경의 변화로 민간투자사업의 위험이 증가되어 민간투자자들이 수익형 민간투자사업에 적극적인 관심을 보이지 않음으로써 수익형 민간투자사업은 상당히 위축되어 있는 상태이다. 이에 본 연구에서는 우리나라에서 민간투자사업을 추진할 경우 정부와 민간사업자가 위험을 분담하는 방식, 즉 기존의 수익형 방식과 임대형 방식의 중간적인 성격을 갖는 위험분담 방식의 혼합형 민간투자 방식을 검토하였고, 우리나라 민간투자사업에 활용될 수 있도록 사례적용 결과를 제시하였다. 본 연구의 결과는 향후 민간투자사업의 활성화에 도움이 될 것으로 기대된다.

혼합현실 기반 중증외상 처치 시뮬레이션 교육 요구 조사: 군병원 간호사 대상 포커스 그룹 인터뷰 적용 (Educational needs of severe trauma treatment simulation based on mixed reality: Applying focus group interviews to military hospital nurses)

  • 장선미;황신우;정유미;정은영
    • 한국간호교육학회지
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    • 제27권4호
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    • pp.423-435
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    • 2021
  • Purpose: The purpose of this study is to identify the educational needs of a severe trauma treatment simulation program based on mixed reality which combines element of both virtual reality and augmented reality. Methods: Focus group interviews were conducted with ten military hospital nurses on February 4 and 5, 2021. The collected data were analyzed using a qualitative content analysis. As a framework for data analysis, the educational needs were clustered into the following four categories: teaching contents, teaching methods, teaching evaluation, and teaching environment. Results: The educational needs for each category that emerged were as follows: three subcategories including "realistic education reflecting actual clinical practice" and "motivating education" for teaching contents; five subcategories including "team-based education," "repeated education that acts as embodied learning," and "stepwise education" for teaching methods; six subcategories including "debriefing through video conferences," "team evaluation and evaluator in charge of the team," "combination of knowledge and practice evaluation" for teaching evaluation; six subcategories including "securing safety," "similar settings to real clinical environments," "securing of convenience and accessibility for learners," and "operating as continuing education" for teaching environment. Conclusion: The findings of this study can provide a guide for the development and operation of a severe trauma treatment simulation program based on mixed reality. Moreover, it suggests that research to identify the educational needs of various learners should be conducted.

Interval Estimation for Sum of Variance Components in a Simple Linear Regression Model with Unbalanced Nested Error Structure

  • Park, Dong-Joon
    • Communications for Statistical Applications and Methods
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    • 제10권2호
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    • pp.361-370
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    • 2003
  • Those who are interested in making inferences concerning linear combination of valiance components in a simple linear regression model with unbalanced nested error structure can use the confidence intervals proposed in this paper. Two approximate confidence intervals for the sum of two variance components in the model are proposed. Simulation study is peformed to compare the methods. The methods are applied to a numerical example and recommendations are given for choosing a proper interval.

Mixed Model Reduction to Improve Steady-State Behaviour of RLC Circuits

  • Lee, Won-Kyu;Victor Sreeram
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2002년도 ICCAS
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    • pp.75.1-75
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    • 2002
  • Several model order reduction methods for large RLC circuits have been developed in the last few years. Krylop subspace based methods are extremely effective for generating the low order models of large system but there is no optimal theory for the resulting models. Alternatively, methods based truncated balanced realization have an optimality property but are too computationally expensive to use on complicated problems such as large RLC circuits. In this paper, we present a method for improving time domain response of reduced order RLC circuits. The method used here is based on combing Krylop subspace based method and truncated balanced realization method plus residualization. The metho...

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고차 시스템의 간소화를 위한 혼합 방법들에 대한 연구 (A Study on Mixed Methods for Reduction of Large Scale System)

  • 권기호;최계근
    • 대한전자공학회논문지
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    • 제24권3호
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    • pp.420-424
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    • 1987
  • The model reduction methods of the linear time invariant continuous systems are proposed. The energy dispersion method is used to obtain the model denominator. And the model numerator is found by the modified residue method or the time moment matching method. The methods suggested are compared with the method suggested by Lucas and give good results.

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황련해독탕 약침액으로 희석한 BU의 신체반응에 관한 연구 (A Study on the Physical Reactions with Administration of BU Mixed Hwangryunhaedoktang(황련해독탕) Herbal Acupucture)

  • 최석우;노정두;설현;소웅룡;육태한
    • Journal of Acupuncture Research
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    • 제20권5호
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    • pp.227-235
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    • 2003
  • Objective : In the pain control, BU herbal acupuncture is highly effective but causes many phys ical reactions. This study was done to compare BU with BU mixed Hwangryunhaedoktang(HHT, 黃連解毒湯) herbal acupucture in decreasing physical reactions of BU. Methods : We injected BU Group(N=12) and BU mixed HHT Group(N=12) at four points of Fenmen(B12), Feishu(B13), Fufen(B41) and Pohu(B42). Then we observe the local thermal changes and the physical reactions at beginning, 1hour and 24 hours after administering herbal acupuncture through the D.I.T.I. and survey. Results : The following results were obtained; 1. The significant dermatothermal difference had been checked 1hour and 24hours in BU group, but 1hour in Bu mixed HHT. 2. In BU group, the difference of temperature had been continued highly until 24hours. But in BU mixed group, the difference of temperature had been continued highly until 1 hour but decreased nearly equal to beginning stage until 24hours. 3. The symptoms which appear following the herbal acupuncture administration were less appeared in BU mixed HHT than BU group.

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