• 제목/요약/키워드: 95% confidence level

검색결과 828건 처리시간 0.031초

극저준위 방사성폐기물의 방사성핵종 분포유형에 기초하여 자체처분기준 만족여부를 판단하기 위한 통계학적 접근방법 (Statistical Approach for Determination of Compliance with Clearance Criteria Based upon Types of Radionuclide Distributions in a Very Low-Level Radioactive Waste)

  • 정재학
    • 방사성폐기물학회지
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    • 제8권2호
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    • pp.123-133
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    • 2010
  • 방사성핵종의 분포유형에 관한 정보에 기초하여 극저준위폐기물의 자체처분 적합성을 통계학적으로 해석할 수 있는 방법론을 개발하였다. 방사성핵종의 분포에 관한 정보를 알 수 없는 경우에 대해서는 널리 알려진 마코프 부등식과 체비셰프 부등식을 적용하여 방사능농도의 산술평균과 허용되는 최대 표준편차의 상관관계식을 제시하였고, 방사성핵종의 농도가 정규분포 또는 로그정규분포를 갖는 경우에 대해서는 확률밀도함수, 누적확률밀도함수 등의 통계학적 관계식을 이용하여 방사능농도의 산술평균과 허용되는 최대 표준편차의 상관관계식을 새롭게 유도하였다. 또한, 자체처분기준 100 Bq/g 및 신뢰수준 95%인 조건에 대한 사례 적용연구를 통하여 방사능농도의 산술평균과 허용되는 표준편차의 범위를 방사성핵종의 분포유형에 따라 정량적으로 비교 제시하고, 자체처분 대상 폐기물의 방사성핵종 분포유형에 관한 정보가 확보될 경우 동일한 신뢰수준에서 자체처분이 허용될 수 있는 범위가 확장될 수 있음을 통계학적으로 입증하였다.

자살 사고와 자살 시도가 있거나 없는 개인의 자살 보도에 대한 태도 연구 (A Study of Attitudes Toward Suicide Report among Individuals with and without Suicidal Thoughts and Suicide Attempts)

  • 고경남;이상욱;박종익
    • 생물정신의학
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    • 제27권1호
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    • pp.9-17
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    • 2020
  • Objectives The purpose of this study is to investigate the interest level, perception and attitude of suicide high-risk group toward the media's suicide report, and also to provide the fundamental data in order to strengthen both the standard and the recommendation of media coverage in Korea. Methods We analyzed the data from the 2013 The Korea National Suicide Survey. The study included 1500 participants aged between 19 and 75 years. The participants were selected through the regional multi-layer stratification method using the sampling frame of the 2010 Census. One-on-one face-to-face interviews investigated the interest level, opinions, and attitudes toward suicide reports and collected data on past suicide history and demographic data. The collected data were evaluated using multiple logistic regression analysis. A probability level of p < 0.05 was considered statistically significant. Results The suicide high risk groups with histories of suicidal ideations or attempts showed more interest in suicidal reports [suicidal thought odds ratio (OR) = 1.81, 95% confidence interval (CI) = 1.40-2.34 ; suicidal attempt OR = 3.21, 95% Cl = 1.52-6.78]. However, there was no difference among the groups in thought that suicide reports incite suicide (suicidal thought OR = 1.26, 95% Cl = 0.92-1.73 ; suicidal attempt OR = 0.96, 95% Cl = 0.44-2.09). The suicide high risk groups showed a positive attitude toward suicide reports, but it was not statistically significant (suicidal thought OR = 1.10, 95% Cl = 0.41-2.92 ; suicidal attempt OR = 1.10, 95% Cl = 0.76-1.59). Conclusions We suggest the need of careful attitude of media suicidal reports not to bring about copycat suicides. and also we offer suicide prevention campaign based on media leverage.

Machine learning modeling and DOE-assisted optimization in synthesis of nanosilica particles via Stöber method

  • Moradi, Hiresh;Atashi, Peyman;Amelirad, Omid;Yang, Jae-Kyu;Chang, Yoon-Young;Kamranifard, Telma
    • Advances in nano research
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    • 제12권4호
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    • pp.387-403
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    • 2022
  • Silica nanoparticles, which have a broad range of sizes and specific surface features, have been used in many industrial applications. This study was conducted to synthesize monodispersed silica nanoparticles directly from tetraethyl orthosilicate (TEOS) with an alkaline catalyst (NH3) based on the sol-gel process and the Stöber method. A central composite design (CCD) is used to build a second-order (quadratic) model for the response variables without requiring a complete three-level factorial experiment. The process was then optimized to achieve the minimum particle size with the lowest concentration of TEOS. Dynamic light scattering and scanning electron microscopy were used to analyze the size, dispersity, and morphology of the synthesized nanoparticles. After optimization, a confirmation test was carried out to evaluate the confidence level of the software prediction. The results revealed that the predicted optimization is consistent with experimental procedures, and the model is significant at the 95% confidence level.

Job Stress and Neuropeptide Response Contributing to Food Intake Regulation

  • Kim, Ki-Woong;Won, Yong Lim;Ko, Kyung Sun;Kang, Seong-Kyu
    • Toxicological Research
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    • 제31권4호
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    • pp.415-420
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    • 2015
  • The purpose of the present study is to investigate the correlations between food intake behavior and job stress level and neuropeptide hormone concentrations. Job strain and food intake behavior were first identified using a self-reported questionnaire, concentrations of neuropeptide hormones (adiponectin, brain derived neurotrophic factor [BDNF], leptin, and ghrelin) were determined, and the correlations were analyzed. In the results, job strain showed significant correlations with adiponectin (odds ratio [OR], 1.220; 95% confidence interval [CI], 1.001~1.498; p < 0.05) and BDNF (OR, 0.793; 95% CI, 0.646~0.974; p < 0.05), and ghrelin exhibited a significant correlation with food intake score (OR, 0.911; 95% CI, 0.842~0.985, p < 0.05). These results suggest that job stress affects food intake regulation by altering the physiological concentrations of neuropeptide hormones as well as emotional status.

성별에 따른 일·생활 균형 인식수준 차이와 일·생활 균형이 부모 자신감에 미치는 영향 (Gender difference of Work-life Balance and the effect of Work-life Balance on Parenting Confidence)

  • 김영형;김혜경
    • 디지털융복합연구
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    • 제20권1호
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    • pp.95-105
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    • 2022
  • 본 연구는 일·생활 균형문화 확산 및 맞벌이 부부의 증가 등으로 변화된 성별에 따른 일·생활 균형 인식수준 차이분석과 일·생활 균형이 부모 자신감에 미치는 영향을 살펴보고자 하였다. 더불어 일·생활 균형이 부모 자신감에 미치는 영향관계에서 경력관리의 조절효과를 살펴보고자 하였다. SPSS 18.0 통계패키지 프로그램을 이용하여 t-검정, 단순선형회귀분석, 위계적 회귀분석을 통해 일·생활 균형, 부모 자신감, 경력관리의 구조적 관계를 규명하였다. 실증분석에는 총505개의 데이터를 활용하였으며, 결과를 요약하면 첫째, 성별에 따른 일·생활 균형 인식수준에 차이가 없는 것으로 나타났으며, 둘째, 일·생활 균형이 부모 자신감에 정(+)의 영향을 미치는 것으로 나타났다. 마지막으로 일·생활 균형이 부모자신감에 미치는 영향관계에서 조직차원의 경력관리가 조절역할을 하는 것으로 나타났다. 이러한 연구결과를 바탕으로 기혼여성인력 활용 및 일·생활 균형지원을 위한 기업의 노력 등에 관한 실용적 시사점 등을 제안했다.

워크샘플링에 의한 학교급식 전담직원의 직무분석 (Work Measurement of Dietetic Staff through Work Sampling Methodology in School Foodservice Systems)

  • 양일선;이영은;차진아;유태용;정라나
    • Journal of Nutrition and Health
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    • 제35권2호
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    • pp.263-271
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    • 2002
  • The purpose of this study was to determine the standard work time of dietetic staff through work sampling methodology in school flood service systems. Work measurement through work sampling methodology was conducted in five conventional, five commissary and five joint management flood service systems over two consecutive weeks in October 1999. Statistical analysis was performed on the SAS/Win 6.12 package program for Kruskal-Wallis test and multiple comparison. Observed data were satisfied with a confidence level of 95% and a confidence interval of $\pm$ 0.05. The results of this study can be summarized as follows. The actual time spent by dietetic staff members in conventional, commissary, joint-management flood servile systems was 2,394, 2,521 and 2,110 minutes per week, respectively. Transportation time of each flood service systeml and ILO allowance rate (11%) was applied. Thus, the standard work time per week of dietetic staff members in conventional, commissary, joint-management flood service systems was 2,746.14, 2,861.58 and 2,520.81 minutes, respectively. The standardized index was 1.04, 1.08 and 0.95 men in conventional, commissary, and joint-management flood service systems, respectively. Regardless of the school flood service system, those with "the duty of cooking and distribution management" had the longest labor time, while those with "duty of nutritional education" had the shortest labor time.

환경방사능 측정에서의 검출한계치의 정량적 고찰 및 최소검출방사능 농도 계산 (Determination of Minimum Detectable Activity in Environmental Samples)

  • 이명호;신현상;홍광희;조영현;이창우
    • Journal of Radiation Protection and Research
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    • 제24권3호
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    • pp.171-184
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    • 1999
  • 본 논문에서는 저준위 환경방사능 측정시 이용되는 검출한계에 대한 기본개념 및 수식을 통계학적 이론을 기초로 서술하였다. 방사능을 정확하게 검출할 신뢰도를 95%로 설정하여 알파 베타 및 감마선 측정기에 대한 검출한계치값을 계산하였다. 또한 환경 방사능 계측에 많이 사용되는 방사능 핵종에 대해 최소 검출 방사능 농도값을 검출한계치 개념을 근거로 계산하여 저준위 환경 방사능 분석시 환경방사능 측정결과에 대한 신뢰도 평가에 활용 가능 하도록 하였다.

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A Forecast Model for the First Occurrence of Phytophthora Blight on Chili Pepper after Overwintering

  • Do, Ki-Seok;Kang, Wee-Soo;Park, Eun-Woo
    • The Plant Pathology Journal
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    • 제28권2호
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    • pp.172-184
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    • 2012
  • An infection risk model for Phytophthora blight on chili pepper was developed to estimate the first date of disease occurrence in the field. The model consisted of three parts including estimation of zoosporangium formation, soil water content, and amount of active inoculum in soil. Daily weather data on air temperature, relative humidity and rainfall, and the soil texture data of local areas were used to estimate infection risk level that was quantified as the accumulated amount of active inoculum during the prior three days. Based on the analysis on 190 sets of weather and disease data, it was found that the threshold infection risk of 224 could be an appropriate criterion for determining the primary infection date. The 95% confidence interval for the difference between the estimated date of primary infection and the observed date of first disease occurrence was $8{\pm}3$ days. In the model validation tests, the observed dates of first disease occurrence were within the 95% confidence intervals of the estimated dates in the five out of six cases. The sensitivity analyses suggested that the model was more responsive to temperature and soil texture than relative humidity, rainfall, and transplanting date. The infection risk model could be implemented in practice to control Phytophthora blight in chili pepper fields.

헬리콥터 조종사의 상황인식과 교육 만족도의 상관분석을 통한 교육개선연구 (A Study on the Improvement of Education through the Correlation Analysis of the Situation Awareness and Education Satisfaction of Helicopter Pilots)

  • 김상철;이용혁
    • 한국항공운항학회지
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    • 제29권1호
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    • pp.82-91
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    • 2021
  • The topic of this paper was analyzed as "t -test" and "multiple regression analysis" for 303 helicopter pilot trainees from aviation schools in the county for "improvement of education through correlation analysis of helicopter pilots' situational awareness and education satisfaction." In addition to the factors for overcoming situational awareness and situational awareness, the level of satisfaction of the instructor and the level of satisfaction of the learning management system (LMS) is the confidence interval p<.05, 95%. It was analyzed to be significant at the level of 05, 95%. Therefore, it was analyzed that in order to improve the "quality of the instructor" in future education, institutional supplementation and "learning management system (LMS)" need to be established including VR and AR so that pilot trainees can use it at all times.

Genotype CC of rs1800947 in the C-Reactive Protein Gene May Increase Susceptibility to Colorectal Cancer: a Meta-Analysis

  • Chen, Xiao-Lin;Liao, Yong-Qiang;Liu, Jian-Rong
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권6호
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    • pp.2663-2667
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    • 2014
  • Background: Single nucleotide polymorphisms of C-reactive protein (CRP) have been shown to be related to circulating CRP level, risk and prognosis in cancer patients. However, accumulating evidence of rs1800947 involvement in risk of cancer is inconsistent. Thus, a meta-analysis was performed to obtain a more precise relationship. Materials and Methods: The pooled odds ratio (OR) and its 95% confidence interval were assessed in 10 eligible articles with 12 studies containing 5,601 cancer cases and 8,669 cancer-free controls. Results: No significant association was observed overall and in subgroups in comparison of genotype GC vs GG ($P_H$=0.847, OR=0.939, 95%CI=0.810-1.087), GC/CC vs GG ($P_H$=0.941, OR=1.021, 95%CI=0.901-1.157) and allele C vs G ($P_H$=0.933, OR=1.026, 95%CI=0.909-1.159). However, statistically significance was evident in comparison of genotype CC vs GG in cancer risk ($P_H$=0.586, OR=2.854, 95%CI= 1.413-5.763), especially in colorectal cancer ($P_H$=0.481, OR=4.527, 95%CI= 1.664- 12.315). Conclusions: Genotype CC of rs1800947 in the CRP gene is strongly associated with increased cancer risk, particularly in colorectal cancer.