• Title/Summary/Keyword: systematic sampling

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Establishing a stability switch criterion for effective implementation of real-time hybrid simulation

  • Maghareh, Amin;Dyke, Shirley J.;Prakash, Arun;Rhoads, Jeffrey F.
    • Smart Structures and Systems
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    • v.14 no.6
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    • pp.1221-1245
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    • 2014
  • Real-time hybrid simulation (RTHS) is a promising cyber-physical technique used in the experimental evaluation of civil infrastructure systems subject to dynamic loading. In RTHS, the response of a structural system is simulated by partitioning it into physical and numerical substructures, and coupling at the interface is achieved by enforcing equilibrium and compatibility in real-time. The choice of partitioning parameters will influence the overall success of the experiment. In addition, due to the dynamics of the transfer system, communication and computation delays, the feedback force signals are dependent on the system state subject to delay. Thus, the transfer system dynamics must be accommodated by appropriate actuator controllers. In light of this, guidelines should be established to facilitate successful RTHS and clearly specify: (i) the minimum requirements of the transfer system control, (ii) the minimum required sampling frequency, and (iii) the most effective ways to stabilize an unstable simulation due to the limitations of the available transfer system. The objective of this paper is to establish a stability switch criterion due to systematic experimental errors. The RTHS stability switch criterion will provide a basis for the partitioning and design of successful RTHS.

Structural Equation Modeling on Living and Brain Death Organ Donation Intention in Nursing Students (간호대학생의 생존 시와 뇌사 시 장기기증 의도에 관한 구조모형)

  • Kim, Eun A;Choi, So Eun
    • Journal of Korean Academy of Nursing
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    • v.45 no.6
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    • pp.802-811
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    • 2015
  • Purpose: The purpose of this study was to test and validate a model to predict living and brain death organ donation intention in nursing students. The conceptual model was based on the theory planned behavior. Methods: Quota sampling methodology was used to recruit 921 nursing students from all over the country and data collection was done from October 1 to December 20, 2013. Results: The model fit indices for the hypothetical model were suitable for the recommended level. Knowledge, attitude, subjective norm and perceived behavioral control explained 40.2% and 40.1% respectively for both living and brain death organ donation intention. Subjective norm was the most direct influential factor for organ donation intention. Knowledge had significant direct effect on attitude and indirect effect on subjective norm and perceived behavioral control. These effects were higher in brain death organ donation intention than in living donation intention. Conclusion: The overall findings of this study suggest the need to develop systematic education programs to increases knowledge about brain death organ donation. The development, application, and evaluation of intervention programs are required to improve subjective norm.

A sample design for life and attitude survey of Gyeongbuk people (경북인의 생활과 의식조사 표본설계)

  • Kim, Dal-Ho;Cho, Kil-Ho;Hwang, Jin-Seub;Jung, Kyung-Ha
    • Journal of the Korean Data and Information Science Society
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    • v.20 no.6
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    • pp.1155-1167
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    • 2009
  • We made a new sample design for life and consciousness survey of Kyungpook people in 2007. We used the 10% sample survey data of 2005 population and housing census as a survey population. After stratification, we allocate proportionally samples within strata after examining various characteristics in previous survey, which includes economic activity state, an income level per year, and housing possession. And we calculated weight in a new sample design and derived estimators and a formula of standard error using the weights.

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Molecular Phylogeny and Divergence Time Estimation of the Soft Coral Dendronephthya gigantea (Alcyonacea: Nephtheidae)

  • Kim, Boa;Kong, So-Ra;Song, Jun-Im;Won, Yong-Jin
    • Animal Systematics, Evolution and Diversity
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    • v.24 no.3
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    • pp.327-332
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    • 2008
  • Soft coral Dendronephthya gigantea (Verrill, 1864) is a conspicuous species dominating shallow sea waters of Jejudo Island, Korea. Recently its whole mitochondrial genome sequencing was completed by us and the sequence information provided an opportunity to test the age of Octocorallia and time of evolutionary separation between some representative orders of the subclass Octocorallia. Molecular phylogenetic analyses based on 13 mitochondrial protein encoding genes revealed a polyphyletic relationship among octocorallians representing two orders (Alcyonacea and Gorgonacea) and four families (Alcyoniidae, Nephtheidae, Briareidae, and Gorgoniidae). Estimates of divergence times among octocorallians indicate that the first splitting might occur around end of or after Cretaceous period (50-79 million years ago (Ma)). The age is relatively young compared to the long history of stony sea corals (>240 Ma). Taken together our result suggests a possible relatively recent radiating evolution at least in the order Alcyonacea and Gorgonacea. Molecular dating and phylogenetic analysis based on much broader taxon sampling and many genes might give an insight into this interesting hypothesis.

DNA Barcoding of Isaacsicalanus paucisetus (Copepoda: Calanoida: Spinocalanidae) from the Hydrothermal Vent in the North Fiji Basin, Southwestern Pacific Ocean

  • Park, Chailinn;Lee, Won-Kyung;Kim, Se-Joo;Ju, Se-Jong
    • Animal Systematics, Evolution and Diversity
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    • v.36 no.2
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    • pp.182-184
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    • 2020
  • Isaacsicalanus paucisetus Fleminger, 1983, a monotypic species of the family Spinocalanidae Vervoort, 1951, was first reported from a hydrothermal vent field in the East Pacific Rise off the mouth of the Gulf of California. The mitochondrial cytochrome oxidase I(mtCOI) DNA barcodes are considered a useful tool to assist traditional taxonomy and species discrimination in calanoid copepods. However, the mtCOI DNA barcodes of I. paucisetus have not been reported due to the species rarity and the difficulty of sampling. In this study, we firstly determined the mtCOI DNA barcodes of the I. paucisetus newly collected from a hydrothermal vent in the North Fiji Basin of the southwestern Pacific. All mtCOI DNA barcodes of I. paucisetus were identical and intraspecies variations of spinocalanid species were 0.0-3.0%. Interspecies and intergeneric variations were 13.4-25.2% and 16.7-24.1%, respectively. The DNA barcodes of I. paucisetus obtained in the present study would be helpful for understanding taxonomic relationships of widespread spinocalanid species.

A Study of the Reformulation of 0-1 Goal Programming (0 - 1 목표계획모형의 재구조화에 관한 연구-기회제약계획법(CCP)과 계층화 분석과정(AHP)의 결합 가능성을 중심으로-)

  • 이영찬;민재형
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1996.04a
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    • pp.525-529
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    • 1996
  • Decision environments involve a high degree of uncertainty as well as multiple, conflicting goals. Although traditional goal programming offers a means of considering multiple, conflicting goals and arrives at a satisficing solution in a deterministic manner, its major drawback is that decision makers often specify aspiration level of each goal as a single number. To overcome the problem of setting aspiration levels, chance constrained programming can be incorporated into goal programming formulation so that sampling information can be utilized to describe uncertainty distribution. Another drawback of goal programming is that it does not provide a systematic approach to set priorities and trade-offs among conflicting goals. To overcome this weekness, the analytic hierarchy process(AHP) is used in the model. Also, most goal programming models in the literature are of a linear form, although some nonlinear models have been presented. Consideration of risk in technological coefficients and right hand sides, however, leads to nonlinear goal programming models, which require a linear approximation to be solved. In this paper, chance constrained reformulation with linear approximation is presented for a 0-1 goal programming problem whose technological coefficients and right hand sides are stochastic. The model is presented with a numerical example for the purpose of demonstration.

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A Study on the Disabled′s Assessment of Accommodation Facilities and Needs for Improving the Facilities (장애유형별 편의시설에 대한 평가 및 개선요구에 관한 연구)

  • 이연숙;장윤정;이기정
    • Korean Institute of Interior Design Journal
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    • no.26
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    • pp.112-120
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    • 2001
  • This study investigated the extend to which the facilities satisfactorily accommodate people with different disabilities and their specific needs for improving the facilities. Systematic interviews were conducted with 90 disabled people using the non-propertionate stratified cluster random sampling method. Frequency analysis, Chi-square tests, Duncan tests, and analysis of variance(ANOVA) were employed for data analysis. The findings indicated that the respondents' assessment of accommodations and needs for improving accommodations differed by the type of disabilities. People with physical disabilities were the least satisfied with stairs, followed by seating in stadiums and/or theaters. For people with visual disabilities, the lack of guidance and information facilities was the most difficult problem. People with hearing disabilities often pointed out difficulties in using public telephones. meanwhile, people with physical disabilities asked for easy access to assistive devices and improved mobility-related circumstances. yet people with visual disabilities expected to improve way-finding relevant issues, such as detectable warnings on walking surfaces and guidance and information facilities, whereas people with hearing disabilities desired to develop hearing-aid equipments, such as TDD and assistive listening systems.

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Factors Associated with Suicide Risk in Advanced Cancer Patients: A Cross-Sectional Study

  • Park, Sun A;Chung, Seung Hyun;Lee, Youngjin
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.11
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    • pp.4831-4836
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    • 2016
  • The study aimed to find out to what degree suicidal thoughts and associated factors affect the suicide risk of advanced cancer patients. The frequency of suicidal thoughts among patients with cancer, especially in the advanced stages, is about 3 times greater than the adult average in South Korea. We recruited 457 participants with four types of cancers (colon, breast, cervical, and lung) using stratified sampling. Data collection was carried out through one-on-one interviews by trained nurses using a structured questionnaire. Advanced cancer patients with high, vs. low, levels of anxiety and pain had a higher suicide risk. In contrast, having one's spouse as the primary care provider was associated with a low suicide risk. Overall, the three factors of anxiety, pain, and the primary caregiver being one's spouse explained 17.2% of the variance in suicide risk. In conclusion, we derived influencing factors of suicide risk using a sample of patients with various types of advanced cancer. The results provide systematic baseline data for preparing nurse-led interventions to prevent suicidal thoughts and suicide attempts among advanced cancer patients.

Bayesian Value of Information Analysis with Linear, Exponential, Power Law Failure Models for Aging Chronic Diseases

  • Chang, Chi-Chang
    • Journal of Computing Science and Engineering
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    • v.2 no.2
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    • pp.200-219
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    • 2008
  • The effective management of uncertainty is one of the most fundamental problems in medical decision making. According to the literatures review, most medical decision models rely on point estimates for input parameters. However, it is natural that they should be interested in the relationship between changes in those values and subsequent changes in model output. Therefore, the purpose of this study is to identify the ranges of numerical values for which each option will be most efficient with respect to the input parameters. The Nonhomogeneous Poisson Process(NHPP) was used for describing the behavior of aging chronic diseases. Three kind of failure models (linear, exponential, and power law) were considered, and each of these failure models was studied under the assumptions of unknown scale factor and known aging rate, known scale factor and unknown aging rate, and unknown scale factor and unknown aging rate, respectively. In addition, this study illustrated developed method with an analysis of data from a trial of immunotherapy in the treatment of chronic Granulomatous disease. Finally, the proposed design of Bayesian value of information analysis facilitates the effective use of the computing capability of computers and provides a systematic way to integrate the expert's opinions and the sampling information which will furnish decision makers with valuable support for quality medical decision making.

An Analysis on Classification Retrieval Operation in University Libraries (대학도서관의 분류검색 운영 분석)

  • Lee Jong-Moon
    • Journal of Korean Library and Information Science Society
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    • v.36 no.2
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    • pp.165-178
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    • 2005
  • This study aims to identify the status of the classification retrieval operation by investigating and analyzing the classification retrieval related to the books in the university libraries. The Investigation concentrated on whether the classification retrieval service is provided, Access Method and classification retrieval level. The data was collected from 97 libraries where URL access was available during the period of survey in 100 libraries selected by the systematic sampling. As a result, while $92.8\%$ of 97 libraries provided the classification retrieval service, $52.2\%$ of it enabled the access to classification retrieval service only by the classification number and $47.8\%$ by classification number and classification directory. Consequently, it was found that the retrieval environment in the libraries where the access was enabled only by classification number should be urgently improved for the activation of classification retrieval.

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