• Title/Summary/Keyword: statistical confidence

Search Result 1,002, Processing Time 0.024 seconds

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

  • Lee, Myung-Ho;Shin, Hyun-Sang;Hong, Kwang-Hee;Cho, Young-Hyun;Lee, Chang-Woo
    • Journal of Radiation Protection and Research
    • /
    • v.24 no.3
    • /
    • pp.171-184
    • /
    • 1999
  • In this paper, using statistical theory the basic concepts and the formulars of lower limit of detection were deasribed. Assuming that risks of 5% are acceptable (95% confidence level), lower limits of detection were calculated on the measuring apparatus for alpha, beta and gamma nuclides. Also, on the basis concepts of lower limit of detection, the MDA values were calculated for the radionuclides detected easily in the environment. These results make it possible to evaluate confidence limits on the radioanalytical results in the environmental sample.

  • PDF

A SELECTION PROCEDURE FOR GOOD LOGISTICS POPULATIONS

  • Singh, Parminder;Gill, A.N.
    • Journal of the Korean Statistical Society
    • /
    • v.32 no.3
    • /
    • pp.299-309
    • /
    • 2003
  • Let ${\pi}_1,...,{\pi}_{k}$k($\geq$2) independent logistic populations such that the cumulative distribution function (cdf) of an observation from the population ${\pi}_{i}$ is $$F_{i}\;=\; {\frac{1}{1+exp{-\pi(x-{\mu}_{i})/(\sigma\sqrt{3})}}},\;$\mid$x$\mid$<\;{\infty}$$ where ${\mu}_{i}(-{\infty}\; < \; {\mu}_{i}\; <\; {\infty}$ is unknown location mean and ${\delta}^2$ is known variance, i = 1,..., $textsc{k}$. Let ${\mu}_{[k]}$ be the largest of all ${\mu}$'s and the population ${\pi}_{i}$ is defined to be 'good' if ${\mu}_{i}\;{\geq}\;{\mu}_{[k]}\;-\;{\delta}_1$, where ${\delta}_1\;>\;0$, i = 1,...,$textsc{k}$. A selection procedure based on sample median is proposed to select a subset of $textsc{k}$ logistic populations which includes all the good populations with probability at least $P^{*}$(a preassigned value). Simultaneous confidence intervals for the differences of location parameters, which can be derived with the help of proposed procedures, are discussed. If a population with location parameter ${\mu}_{i}\;<\;{\mu}_{[k]}\;-\;{\delta}_2({\delta}_2\;>{\delta}_1)$, i = 1,...,$textsc{k}$ is considered 'bad', a selection procedure is proposed so that the probability of either selecting a bad population or omitting a good population is at most 1­ $P^{*}$.

Effective Validation Model and Use of Mobile-Health Applications for the Elderly

  • Lopez, Leonardo Juan Ramirez;Pinto, Edward Paul Guillen;Linares, Carlos Omar Ramos
    • Healthcare Informatics Research
    • /
    • v.24 no.4
    • /
    • pp.276-282
    • /
    • 2018
  • Objectives: Due to the uncontrolled increase of the mobile health applications and their scarce use by elderly for reason of absence credibility of measurements by lack scientific support, the aim of this study was to evaluate the differences between the biophysical measurements based on standard instrument against a mobile application using controlled experiments with elderly to propose an effective validation model of the developed apps. Methods: The subjects of the study (50 people) were elderly people who wanted to check their weight and cardiac status. For this purpose, two mobile applications were used to measure energy expenditure based on physical activity (Activ) and heart rate (SMCa) during controlled walking at specific speeds. Minute-by-minute measurements were recorded to evaluate the average error and the accuracy of the data acquired through confidence intervals by means of statistical analysis of the data. Results: The experimental results obtained by the Activ/SMCa apps showed a consistent statistical similarity with those obtained by specialized equipment with confidence intervals of 95%. All the subjects were advised and trained on the use of the applications, and the initial registration of data to characterize them served to significantly affect the perceived ease of use. Conclusions: This is the first model to validate a health-app with elderly people allowed to demonstrate the anthropometric and body movement differences of subjects with equal body mass index (BMI) but younger. Future studies should consider not only BMI data but also other variables, such as age and usability perception factors.

Statistical Estimation for Hazard Function and Process Capability Index under Bivariate Exponential Process (이변량 지수 공정 하에서 위험함수와 공정능력지수에 대한 통계적 추정)

  • Cho, Joong-Jae;Kang, Su-Mook;Park, Byoung-Sun
    • Communications for Statistical Applications and Methods
    • /
    • v.16 no.3
    • /
    • pp.449-461
    • /
    • 2009
  • Higher sigma quality level is generally perceived by customers as improved performance by assigning a correspondingly higher satisfaction score. The process capability indices and the sigma level $Z_{st}$ ave been widely used in six sigma industries to assess process performance. Most evaluations on process capability indices focus on statistical estimation under normal process which may result in unreliable assessments of process performance. In this paper, we consider statistical estimation for bivariate VPCI(Vector-valued Process Capability Index) $C_{pkl}=(C_{pklx},\;C_{pklx})$ under Marshall and Olkin (1967)'s bivariate exponential process. First, we derive some limiting distribution for statistical inference of bivariate VPCI $C_{pkl}$. And we propose two asymptotic normal confidence regions for bivariate VPCI $C_{pkl}$. The proposed method may be very useful under bivariate exponential process. A numerical result based on our proposed method shows to be more reliable.

Suggestion of a Groundwater Quality Management Framework Using Threshold Values and Trend Analysis (문턱값과 추세분석을 이용한 지하수 수질관리체계 구축을 위한 연구)

  • An, Hyeonsil;Jee, Sung-Wook;Lee, Soo Jae;Hyun, Yunjung;Yoon, Heesung;Kim, Rak-Hyeon
    • Journal of Soil and Groundwater Environment
    • /
    • v.20 no.7
    • /
    • pp.112-120
    • /
    • 2015
  • Statistical trend analysis using the data from the National Groundwater Quality Monitoring Network (NGQMN) of Korea was conducted to establish a new groundwater quality management framework. Sen’s test, a non-parametric statistical method for trend analysis, was used to determine the linear trend of the groundwater quality data. The analysis was conducted at different confidence levels (i.e., at 70, 80, 90, 95, and 99% confidence levels) for three of groundwater quality parameters, i.e., nitrate-nitrogen, chloride, and pH, which have sufficient time series of the NGQMN data between 2007 and 2013. The results showed that different trends can be determined for different depths even for the same monitoring site and the numbers of wells having significant trends vary with different confidence levels. The wells with increasing or decreasing trends were far less than the wells with no trend. Chloride had more wells with increasing trend than other parameters. On the other hand, nitrate-nitrogen had the most wells with increasing trend and concentration exceeding 75% of the threshold values (TVs). Based on the methodology used for this study, we suggest including groundwater TVs and trend analysis to evaluate groundwater quality and to establish an advanced groundwater quality management framework.

The Effects of Food and Nutrition Information in Mass Media on Adolescents' Dietary Behaviors (대중매체의 식품영양정보가 청소년의 식행동에 미치는 영향)

  • Yoon, Soongyi;Yoo, Hyesook
    • Journal of The Korean Society of Integrative Medicine
    • /
    • v.4 no.2
    • /
    • pp.109-120
    • /
    • 2016
  • Purpose : This study surveyed the relationship between the dietetic behaviors of high school students and nutrition information available from mass media thereby suggesting the way of improving the dietetic health promotion of adolescents. Method : This study surveyed coeducational high school students in S region. 220 questionnaires have been collected and analyzed, which is statistically significant as in other previous studies. The survey lasted for one month, March 14 through April 14 in 2016. The statistical analysis was performed by using the windows version 21.0 of SPSS. Primarily, the frequency analysis and descriptive statistics was carried out on the general information, the usage and confidence of mass media, and the diabetic behaviors of respondents. t-Test and One-way ANOVA were adopted to clarity the mass media usage and diabetic behaviors of respondents for general characteristics. Result : The statistical analysis on the diet usage of mass media among high school students shows that famous restaurants(Response rate 51%) and diet control(20%) are highly evaluated, but disease prevention(15%) is low. Regarding the dietetic information acquisition, the mass media including TV, radio, and Internet appear as main information carriages (p<.001). The confidence in mass media are analyzed in the relation with 10 dietetic behaviors, and 4 items(meal amount: p<.011, vegetable intake: p<.005, protein intake: p<.003) are inversely related to the mass media, which means regular intake party is less dependent of the exterior information. The seaweed(p<.017) intake is statistically significant in confidence level. Conclusion : To increase the interest and the health promotion of students, the dietetic information need to be offered in mass media and education course.

A Study on the Structural Relationship of Achievement Goal Propensity, Sports Confidence, and Perceived Performance Using the Mentoring System of High School Leaders (고등학교 지도자의 멘토링시스템을 활용한 성취목표성향, 스포츠 자신감 및 인지된 경기력의 구조적 관계 고찰)

  • Kim, Seon-Il;Cho, Ki-Jung;Han, Dong-Sung
    • Journal of Korea Entertainment Industry Association
    • /
    • v.15 no.6
    • /
    • pp.153-163
    • /
    • 2021
  • This study has a main purpose that closely examines the structural relationship among A Study on the Structural Relationship of Achievement Goal Propensity, Sports Confidence, and Perceived Performance Using the Mentoring System of High School Leaders. In order to achieve it, the sample from high school student participants were accumulated by using convenience sampling that chose taekwondo championship in national. The samples were 500 people. and we excluded unsuitable sheet like that were decided as untruthful one and an omission and unclear. So the final samples were 465 people. On the basis of that, The statistical techniques, spss 24.0 and amos 24.0 program have been used for the analysis as per research purpose. The statistical analysis used in the research for a data analysis includes frequency analysis, confirmatory factor analysis, reliability analysis, correlation analysis, and structure equation model analysis. The research has drawn the following conclusions, based on the above mentioned research method and its procedures: First, The mentoring influences the achievement goal orientation. Second, The mentoring influences the sport confidence. Third, The achievement goal orientation influences the perceived performance. Fourth, The sport confidence influences the perceived performance.

Evaluation of the Confidence and Learning Effects of Dental Hygiene Ethical Decision-Making through Dental Hygiene Ethics Subjects (치위생(학)과 학생들의 치위생윤리 교과목을 통한 치위생 윤리적 의사결정에 대한 자신감과 학습성과 평가)

  • Jung-Hui Son;Sun-Jung Shin
    • Journal of Korean Dental Hygiene Science
    • /
    • v.6 no.2
    • /
    • pp.91-100
    • /
    • 2023
  • Background: This study evaluated the learning outcomes of dental hygiene students' ethical consciousness and ethical decision-making competence through dental ethics courses conducted in some universities. Methods: The subjects were 35 and 29 fourth-year dental hygiene students at G University in the first semester of 2021 and 2022, respectively, and 53 and 43 third-year dental hygiene students at D University, respectively, for a total of 160 students. After implementing the dental hygiene ethics course, classroom performance was evaluated in terms of moral sensitivity, confidence in making ethical decisions, classroom practicality, learning outcomes, and class satisfaction. Statistical analysis was conducted using independent t-test and paired t-test, and the statistical significance level was 0.05. Results: Both universities reported an increase in moral sensitivity and confidence in ethical decision-making after the course (p<0.001). Classroom practicality and class satisfaction for the dental hygiene ethics course did not differ between disciplines and were rated positively with a score of 4 or higher (p>0.05). Learning outcomes were higher among 4-year students than 3-year students (p<0.001). Conclusions: It was evaluated that the ethics in dental hygiene curriculum can strengthen students' competence in ethical decision-making, including moral sensitivity and confidence in solving ethical problems in dental hygiene.

A Study for Statistical Criterion in Negative Association Rules Using Boolean Analyzer

  • Lee, Keun-Woo;Park, Hee-Chang
    • Journal of the Korean Data and Information Science Society
    • /
    • v.19 no.2
    • /
    • pp.569-576
    • /
    • 2008
  • Association rule mining searches for interesting relationships among items in a given database. Association rules are frequently used by retail stores to assist in marketing, advertising, floor placement, and inventory control. There are three primary quality measures for association rule, support and confidence and lift. Association rule is an interesting rule among purchased items in transaction, but the negative association rule is an interesting rule that includes items which are not purchased. Boolean Analyzer is the method to produce the negative association rule using PIM. But, PIM is subjective. In this paper, we present statistical objective criterion in negative association rules using Boolean Analyzer.

  • PDF

Exploiting a Statistical Threshold for Efficiently Identifying Correlated Pairs

  • Kim, Myoung-Ju;Park, Hee-Chang
    • Journal of the Korean Data and Information Science Society
    • /
    • v.19 no.2
    • /
    • pp.551-558
    • /
    • 2008
  • Association rule mining searches for interesting relationships among items in a given database. Association rules are frequently used by retail stores to assist in marketing, advertising, floor placement, and inventory control. There are three primary quality measures for association rule, support and confidence and lift. If there is many item in the association rule, much time is required. Xiong(2004) studies new method which is to compute the support of upper. They used support of upper to the $^{\theta}$. But $^{\theta}$ is subjective. In this paper, we present statistical objective criterion for efficiently identifying correlated pairs.

  • PDF