• Title/Summary/Keyword: Subgroup Method

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Numerical Classification of Phototrophic Nonsulfur Bacteria (수리분류학적 방법에 의한 비유황 광합성 세균 분류)

  • 이현순;이상섭;윤병수
    • Korean Journal of Microbiology
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    • v.23 no.3
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    • pp.235-240
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    • 1985
  • A total of 10 main characters of 16 species of family Rhodospirllaceae were phenetically and cladistically analyzed by Farris' method. The obtained phenogram and cladistic tree were compared with Bergey's manual and other papers. The results supported that the system of 5 subgroups (genera) is available in family Rhodospirllaceae and indicated that close affinities between Rhodospirllum tenue and Rhodopseudomonas gelatinosa and between Rhodomicrobium vannielii and other species of genus Rhodopseudomonas were proved.

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Bayesian Method for Combining Results from Different Poisson Experiments

  • Cho, Jang Sik;Kim, Dal Ho
    • Communications for Statistical Applications and Methods
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    • v.7 no.2
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    • pp.533-540
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    • 2000
  • The problem of information related to I poission experiments, each having a distinct failure rate $\theta$i I=1,2,…,I, is considered. Instead of using a standard exchangeable prior for $\theta$=($\theta$1,$\theta$2,…,$\theta$I), we consider a partition of the experiments and take the $\theta$i's belonging to the same partition subgroup to be exchangeable and the $\theta$i's belonging to distinct subgroups to be independent. And we perform Gibbs sampling approach for Bayesian inference on $\theta$ conditional on a partition. Numerical study using real data is provided.

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Carbon Containing Compositions

  • Mansurova, R.M.;Mansurov, Z.A.;Soh, Deawha
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.335-338
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    • 2001
  • With the use of the electron microscopy and X-ray phase analysis the regularities of carbon deposit formation in process of methane and propane pyrolysis on the zeolites, Kazakhstan natural clays, chrome and bauxite sludge containing metal oxides of iron subgroup, have been studied. In process of over-carbonization the trivalent iron was reduced to metal form. In addition, the carbon tubes of divers morphology had been impregnated with ultra-dispersed metal particles. The kinetic parameters of carbon formation in process of methane decomposition on the zeolite CoO mixture surface were investigated by method of thermo-gravimetric analysis. The morphology and structure of formed carbon fibrils, with the metal particles fixed at their ends, have been investigated, the formation of branched carbon fibrils pattern, so called octopus, being found.

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Results of the First Round-Robin-Test for Evaluation of Mechanical Properties in Bi-2223 Composite Superconductors (산화물 복합초전도체(Bi-2223)의 기계적특성 평가를 위한 라운드로빈 시험 결과)

  • 신형섭
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2001.02a
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    • pp.13-16
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    • 2001
  • In the practical sense, it is important to assess the Young modulus and the degradation of $I_{c}$ due to mechanical deformation in HTS tapes for designing superconducting magnets. In order to establish a test method of mechanical properties in oxide composite superconductors, the committee of VAMAS/TWA 16-Subgroup proposed an international round robin test. The first effort has been focused on the multifilamentary Bi-2223 tapes. Eight groups participated in the RRT activity and each group carried out the tensile test by their own professional technique to three kinds of Bi-2223 tapes. The experimental details were reported and discussed for your information.

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Carbon Containing Compositions

  • Mansurova, R.M.;Mansurov, Z.A.
    • Transactions on Electrical and Electronic Materials
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    • v.2 no.2
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    • pp.5-15
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    • 2001
  • The experiment established optimal conditions for over-carbonization. With the use of the electron microscopy and X-ray phase analysis the regularities of carbon deposit formation in process of methane and propane pyrolysis on the zeolites, Kazakhstan natural clays, chrome and bauxite sludge containing metal oxides of iron subgroup, have been studied. In process of over-carbonization the trivalent iron was reduced to metal form. In addition, the carbon tubes of divers morphology had been impregnated with ultra-dispersed metal particles. The kinetic parameters of carbon formation in process of methane decomposition on the zeolite - CoO mixture surface were investigated by method of thermo-gravimetric analysis. The morphology and structure of formed carbon fibrils, with the metal particles fixed at their ends, have been investigated, the formation of branched carbon fibrils pattern, so called octopus, being found. Also, the walnut shells and grape kernel carbonization, their immobilization by the cells of selective absorption of heavy metal and sulfur dioxide ions have been studied. The example of metal-carbon composites used as adsorbents for wastewater purification, C$_3$- C$_4$ hydrocarbon cracking catalysts and refractory materials with improved properties have been considered.

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Comparison of Statistical Process Control Techniques for Short Production Run (단기 생산공정에 활용되는 SPC 기법의 비교 연구)

  • Seo, Sun-Keun;Lee, Sung-Jae;Kim, Byung-Tae
    • Journal of Korean Society for Quality Management
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    • v.28 no.2
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    • pp.70-88
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    • 2000
  • Short runs where it is neither possible nor practical to obtain sufficient subgroups to estimate accurately the control limit are common in modem business environments. In this study, the standardized control chart, Hillier's exact method, Q chart, EWMA(Exponentially Weighted Moving Average) chart for Q statistics and EWMA chart for mean and absolute deviation among many SPC(Statistical Process Control) techniques for short runs have been reviewed and advantages and disadvantages of these techniques are discussed. The simulation experiments to compare performances of these variable charts for process mean and variations are conducted for combination of subgroup size, scale and timing of shifts of process mean an/or standard deviation. Based upon simulation results, some guidelines for practitioners to choose short run SPC techniques are recommended.

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Designing a Microworld for Recursive Pasterns and Algebra (재귀적 패턴과 거북 마이크로월드 설계)

  • Kim Hwa-Kyung
    • The Mathematical Education
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    • v.45 no.2 s.113
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    • pp.165-176
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    • 2006
  • In this paper, we consider changes of algebra strands around the world. And we suggest needs of designing new computer environment where we make and manipulate geometric recursive patterns. For this purpose, we first consider relations among symbols, meanings and patterns. And we also consider Logo environment and characterize algebraic features. Then we introduce L-system which is considered as action letters and subgroup of turtle group. There are needs to be improved since there exists some ambiguity between sign and action. Based on needs of improving the previous L-system, we suggest new commands in JavaMAL microworld. So we design a microworld for recursive patterns and consider meanings of letters in new environments. Finally, we consider the method to integrate L-system and other existing microworlds, such as Logo and DGS. Specially, combining Logo and DGS, we consider the movement of such tiles and folding nets by L-system commands. And we discuss possible benefits in this environment.

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Detection of Cucumber Mosaic Virus by RT-PCR Using a Simple and Rapid Crude Sap Extraction Method (간이 조즙액 추출법을 이용한 RT-PCR 방법에 의한 오이 모자이크 바이러스의 검정)

  • 이상용;홍진성;이진상;최장경
    • Korean Journal Plant Pathology
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    • v.12 no.4
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    • pp.432-436
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    • 1996
  • 역전사 중합효소 연쇄반응(RT-PCR)을 이용하여 담배(Nicotiana glutinosa)에 증식시킨 7종의 오이 모자이크 바이러스(CMV)를 검정하였다. RT-PCR을 위한 간단하고 신속한 바이러스 핵산의 조즙액 추출법이 개발되었으며, CMV 외피단백질 유전자 부위를 기초로 하여 제작한 20개의 염기로 구성된 primer를 사용하여 RT-PCR을 실시한 결과, 약 490 염기쌍의 DNA 단편들이 이병식물의 조즙액으로부터 증폭되었다. EcoRI 및 MspI을 이용한 RT-PCR 산물의 분석에 의하여, 공시한 7종의 바이러스는 모두 CMV subgroup I으로 동정되었다. Ouchterlony 한천젤 이중 확산법을 이용한 항혈청 검정에서도 7종의 바이러스 모두 CMV-Y의 항혈청과 단일의 침강선을 형성하였다.

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Application of Standardization for Causal Inference in Observational Studies: A Step-by-step Tutorial for Analysis Using R Software

  • Lee, Sangwon;Lee, Woojoo
    • Journal of Preventive Medicine and Public Health
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    • v.55 no.2
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    • pp.116-124
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    • 2022
  • Epidemiological studies typically examine the causal effect of exposure on a health outcome. Standardization is one of the most straightforward methods for estimating causal estimands. However, compared to inverse probability weighting, there is a lack of user-centric explanations for implementing standardization to estimate causal estimands. This paper explains the standardization method using basic R functions only and how it is linked to the R package stdReg, which can be used to implement the same procedure. We provide a step-by-step tutorial for estimating causal risk differences, causal risk ratios, and causal odds ratios based on standardization. We also discuss how to carry out subgroup analysis in detail.

Evaluation of Cost-Effectiveness of Medical Nutrition Therapy : Meta-Analysis (메타분석을 이용한 임상영양서비스의 비용-효과성 평가)

  • 김현아;양일선;이해영;이영은;박은철;남정모
    • Journal of Nutrition and Health
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    • v.36 no.5
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    • pp.515-527
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    • 2003
  • Objectives: A meta-analysis of the literatures was conducted to evaluate the cost-effectiveness of medical nutrition therapy by dietitians. Methods : The 30 studies were identified from a computerized search of published research on MEDLINE, Science-Direct and the PQD database until May, 2002 and a review of reference lists. The main search terms were“dietitian”,“dietary intervention”,“nutrition intervention”, “cost”,“cost-effectiveness”and“cost-benefit analysis”. The subgroup analysis was performed by publication year, study design, intervention provider, type of patient (in/out-patient) and type of cost (total cost/direct cost). Two reviewers independently selected trials for inclusion, assessed the quality and extracted the data. Results : The 30 studies were identified using the electric database search and bibliographies. The 17 trials were eligible for inclusion criteria, then the systematic review and a meta-analysis were conducted on effectiveness and cost-effectiveness of medical nutrition therapy. The quality of the studies was evaluated using the quality assessment tool for observational studies. The quality score was 0.515 $\pm$ 0.121 (range : 0.279-0.711, median : 0.466). The meta-analysis of 17 studies based on the random effect model showed that medical nutrition therapy was highly effective in treating the diseases (effect size 0.3092 : 95% confidence interval 0.2282-0.3303). The vote-counting method, one of meta-analysis methods, was applied to evaluate the cost-effectiveness of medical nutrition therapy conducted by dietitians. Two criteria (method 1, method 2) for voting were used. The calculated p-values for method 1 (more conservative method) and method 2 (less conservative method) were 0.1250 and 0.0106, respectively. Medical nutrition therapy by dietitians was significantly cost-effective in the method 2. Conclusion. This meta-analysis showed that the effectiveness of medical nutrition therapy was statistically significant in treating disease (effect size 0.3092), and that the cost-effectiveness of medical nutrition therapy was statistically significant in the method 2 (less conservative method) of vote counting. (Korean J Nutrition 36(5): 515~527, 2003)