• 제목/요약/키워드: systematic research

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An Approach for the Uncertainty Evaluation of the Overall Result from Replications of Measurement: Separately Combining Individual Uncertainty Components According to their 'systematic' and 'random' Effects

  • Kim, In Jung;Kim, Byungjoo;Hwang, Euijin
    • Bulletin of the Korean Chemical Society
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    • 제35권4호
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    • pp.1057-1060
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    • 2014
  • In our previous articles, an approach has been proposed for the evaluation of the uncertainty of overall result from multiple measurements. In the approach, uncertainty sources were classified into two groups: the first including those giving same 'systematic' effect on each individual measurement and the second including the others giving 'random' effect on each individual measurement and causing a variation among individual measurement results. The arithmetic mean of the replicated measurements is usually assigned as the value for the overall result. Uncertainty of the overall result is determined by separately evaluating and combining an overall uncertainty from sources of the 'systematic' effect and another overall uncertainty from sources of the 'random' effect. This conceptual approach has been widely adopted in chemical metrology society. In this study, further logical proof with more detailed mathematical expressions is provided on the approach.

The Balancing Act of Action and Learning: A Systematic Review of the Action Learning Literature

  • CHO, Yonjoo
    • Educational Technology International
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    • 제9권1호
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    • pp.1-23
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    • 2008
  • Despite considerable commitment to the application of action learning as an organization development intervention, no identified systematic investigation of action learning practices has been reported. Based on a systematic literature review, the purpose of this paper is to identify whether researchers strike a balance between action and learning in their studies of action learning. Research findings in this study included: (1) only 32 empirical studies were found from the electronic database search; (2) based on the hypothesized continuum of Revans' original proposition of balancing action and learning, the author categorized 32 studies into three groups: action-oriented, learning-oriented, and balanced action learning; (3) there were only nine studies on balanced action learning among 32 empirical studies, whose insights included an effective use of project teams, applications of action learning for organization development, and key success factors such as time, reflection, and management support; (4) case study was among the most frequently used research method and only six quality studies met key methodological traits; and (5) therefore, more rigorous empirical research employing quantitative methods as well as case studies is needed to determine whether researchers strike a balance between action and learning in studies on action learning.

항로표지 정보를 이용한 해상감시레이더의 시스템 오차 보정 (Systematic Error Correction of Sea Surveillance Radar using AtoN Information)

  • 김병두;김도형;이병길
    • 한국항해항만학회지
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    • 제37권5호
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    • pp.447-452
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    • 2013
  • 해상교통관제시스템(VTS)은 선박의 위치, 속도, 침로 등 해상 교통 정보를 획득하기 위하여 다수의 해상감시레이더를 주요 센서로 이용하고 있으며, 거리 및 방위각 바이어스와 같은 2차원 해상감시레이더의 시스템 오차는 레이더 영상 및 표적 추적정보의 정확도를 크게 저하시킬 수 있다. 따라서 해상교통관제시스템에서 정확한 표적정보를 제공하기 위하여 레이더의 시스템 오차는 정밀하게 보정되어야 한다. 본 논문에서는 VTS 관제영역에 설치된 항로표지의 위치정보를 이용하여 2차원 해상감시레이더의 거리 및 방위각 오차를 보정하기 위한 방법을 제안한다. 2차원 레이더 측정값의 표준오차 모델과 항로표지 위치정보로부터 측정 잔차 모델을 유도하고, 레이더 시스템 오차를 추정하기 위한 선형 칼만필터를 설계한다. Monte-Carlo 모의실험을 통하여 제안한 방법을 검증하고, 항로표지 정보의 개수에 따른 레이더 시스템 오차 추정의 수렴 특성 및 정확도를 분석한다.

Systematic Relationships of Korean Freshwater Snails of Semisulcospira, Koreanomelania, and Koreoleptoxis (Cerithiodiea; Pleuroceridae) revealed byMitochondrial Cytochrome Oxidase I Sequences

  • Kim, Woo-Jin;Kim, Dae-Hee;Lee, Jun-Sang;Bang, In-Chul;Lee, Wan-Ok;Jung, Hyung-Taek
    • 한국패류학회지
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    • 제26권4호
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    • pp.275-283
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    • 2010
  • Many freshwater snail taxa are difficult to identify using morphological traits due to phenotypic plasticity. However, using of molecular DNA marker in combination with morphological traits can provide a reliable means for discriminating among freshwater snail taxa including cryptic species. To discriminate among Korean freshwater snail taxa and resolve their systematic relationships, wesequenced a fragment of mtDNA cytochrome oxidase I (COI) gene from 82 specimens collected from ten different sites distributed along the Korean peninsula. We identified more than seven freshwater snail taxa including cryptic species in Korea. Whereas traditional shell morphology of freshwater snails offers only weak discriminatory power for recognizing 'good' taxa, DNA sequence data provided positive and reliable identification. In addition, a major Semisulcospira clade was clearly separated from the remaining lineages observed including cryptic species. However, a phylogenetic tree inferred from the COI gene data did not fully resolve systematic relationships among pleurocerid taxa in Korea. Establishing more robust shell characteristics for identifying taxa unambiguously and hence improving traditional key shell morphology characters for freshwater snail species is an urgent requirement and will require more rigorous examination of all nominal taxa. While molecular data generated here will be useful for species identification and for describing the systematic relationships among Korean freshwater snails, further analysis will be required.

Application of Stem Cells in Targeted Therapy of Breast Cancer: A Systematic Review

  • Madjd, Zahra;Gheytanchi, Elmira;Erfani, Elham;Asadi-Lari, Mohsen
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권5호
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    • pp.2789-2800
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    • 2013
  • Background: The aim of this systematic review was to investigate whether stem cells could be effectively applied in targeted therapy of breast cancer. Material and Method: A systematic literature search was performed for original articles published from January 2007 until May 2012. Results: Nine studies met the inclusion criteria for phase I or II clinical trials, of which three used stem cells as vehicles, two trials used autologous hematopoetic stem cells and in four trials cancer stem cells were targeted. Mesenchymal stem cells (MSCs) were applied as cellular vehicles to transfer therapeutic agents. Cell therapy with MSC can successfully target resistant cancers. Cancer stem cells were selectively targeted via a proteasome-dependent suicide gene leading to tumor regression. $Wnt/{\beta}$-catenin signaling pathway has been also evidenced to be an attractive CSC-target. Conclusions: This systematic review focused on two different concepts of stem cells and breast cancer marking a turning point in the trials that applied stem cells as cellular vehicles for targeted delivery therapy as well as CSC-targeted therapies. Applying stem cells as targeted therapy could be an effective therapeutic approach for treatment of breast cancer in the clinic and in therapeutic marketing; however this needs to be confirmed with further clinical investigations.

침(鍼)의 근거중심적(根據中心的) 연구동향(硏究動向)에 관(關)한 고찰(考察) - Systematic review & Meta-analysis를 중심으로 - (The Review on the Evidence-Based Study of Acupuncture - Systematic review and Meta-analysis -)

  • 백용현;박동석;강성길
    • Journal of Acupuncture Research
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    • 제19권3호
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    • pp.138-155
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    • 2002
  • Objective : The purpose of this study is to work on the problems and on the direction of the study regarding the evidence-based study of Acupuncture. Methods : We reviewed the PubMed electronic database. Eight articles of systematic review without meta-analysis and six articles without meta-analysis were selected. Results : In the study of eight articles of systematic review without meta-analysis, there were two articles on effectiveness of acupuncture and one on non-effectiveness of acupuncture. Four articles were about the changes according to the quality of randomized controlled trials. Also, one article was about the side-effect of acupuncture. In the study of six articles of systematic review with meta-analysis, there were two articles on Odds Ratio, two on Relative Risk, one on number-needed-to-treat, and two on 18 predefined methodological criteria. Conclusion : As the quality of RCTs was high, positive response decreased and as the quality of RCTs was low, positive response increased. For the study of evidence-based acupuncture, it is necessary that we conduct research on well-planned placebo acupuncture, large sample size, statistical method, method of searching and assessing literature and method of meta-analysis.

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An Empirical Analysis on a Predictive Method of Systematic Segmentation in Volatile High-Tech Markets

  • Shin, Yonghee;Jeon, Hyori;Choi, Munkee;Han, Eoksoo;Jung, Sungyoung
    • ETRI Journal
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    • 제35권2호
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    • pp.321-331
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    • 2013
  • High-tech markets are unpredictable owing to rapid technology innovation, diverse customer needs, high competition, and other elements. Many scholars have attempted to explain the uncertainty in high-tech markets using their own various approaches. However, sufficiently clear ways to predict diverse changes and trends in high-tech markets have yet to be presented. Thus, this paper proposes a new approach model, that is, systematic market segmentation, to give more accurate information. Using an empirical dataset from the mobile handset market in the Republic of Korea, we conduct our research model consisting of three steps. First, we categorize nine basic segments. Second, we test the stability of these segments. Finally, we profile the characteristics of the customers and products. We conclude that the approach is able to offer more diagnostic information to both practitioners and scholars. It is expected to provide rich information for an appropriate marketing mix in practice.

초등학생 대상의 국내 구강건강관리 프로그램에 대한 체계적 문헌고찰 (A systematic review of domestic oral health care programs for elementary school children)

  • 여안나;이수영
    • 한국치위생학회지
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    • 제20권3호
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    • pp.257-268
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    • 2020
  • Objectives: This purpose of this study was to examine the trends in interventional research and analyze the contents and results of intervention through a systematic literature review of the domestic research literature, suggesting the effect of an oral care program on elementary school students. Methods: A total of 262 articles were retrieved initially, and the duplicate articles were then removed, excluded after screening titles, abstracts, and full-text articles. Finally, a total of 16 papers were used in the review. Results: The study included 9 articles with the nonequivalent control group pretest-posttest design and 7 with the one-group pretest-posttest design. All articles were of non-randomized studies. The most common index of the interventional effect was dental plaque. Further, oral health behaviors and knowledge, perception, self-efficacy, and DMFT index were common indices. In the quality assessment, in the "blinding of outcome assessment" among six items of ROBANS, 12 studies showed a high risk of bias. Conclusions: In order to develop an interventional oral health care program for elementary school students and evaluate the effectiveness, a strict research design and qualitative improvement of research reports are required, and continuous research should be conducted to develop a systematic protocol.

국내 간호대학생 대상 재난간호 연구의 동향 : 체계적 문헌고찰 (Trends of Nursing Research on Disasters for Nursing Students in Korea: A Systematic Review)

  • 강숙정;하지혜
    • 한국보건간호학회지
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    • 제36권1호
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    • pp.90-106
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    • 2022
  • Purpose: This study was conducted to identify trends of nursing research on disaster for nursing students in Korea through a systematic review. Methods: A systematic review was conducted across international and domestic electronic databases, and 13 of 506 studies were identified for this review. Results: The most commonly used variables in the study were 'disaster nursing competency (23.5%)' and 'disaster awareness (20.6%)'. In addition, the major factors influencing the disaster nursing competency of nursing students were analyzed as 'disaster preparedness'. However, many tools were developed for the needs of researchers rather than those that were sufficiently valid and reliable. Also, most studies did not use the theoretical framework. Conclusion: There is necessary to develop an instrument with confirmed reliability and validity to measure disaster nursing competency of nursing students. Finally, disaster education and research should be conducted based on the theoretical framework to enhance the disaster nursing competency of nursing students.