Psychometric Properties of Persian Translated Version of Activities-specific Balance Confidence Scale (ABC in Arak Community-dwelling Older Adults

Directory of Open Access Journals (Sweden)

Daryoush Khajavi

2017-11-01

Full Text Available Abstract Background: Balance deficiency, falls and fear of fall are important problems that can resulted in reversed health outcomes including decreased quality of life. The purpose of this study was surveying factor structure, validation, and reliability determination of Persian translated version of Activities-specific Balance Confidence scale in community-dwelling older adults of Arak city. Materials and Methods: Research method was descriptive in form of psychometry. The statistic population was older adults of Arak in year 2012 and 308 subjects with mean age 69.38 years were selected availably. Data were collected by Persian translated version of Activities-specific Balance Confidence that is a 16-item scale and evaluates balance confidence in activities of daily living. Data were analyzed by Exploratory Factor Analysis. Test-retest and internal reliability were calculated by Pearson correlation coefficient and Chronbach’s Alpha. Data were analyzed with SPSS-16. Results: The findings resulted in extraction of one factor with eigenvalue over one that explained 82.89% of total variance. Test-retest reliability between 1 to 4 weeks and internal reliability (Chronbach’s alpha were 0.82 and 0.98, respectively. Gutmann split-half correlation coefficient and intra-class correlation coefficient were calculated 95% and 85%, respectively. Conclusion: Persian translated version of Activities-specific Balance Confidence (ABC-F is a valid and reliable tool for Iranian community-dwelling older adults that can be used in clinical and research purpose.

Correlation Coefficients: Appropriate Use and Interpretation.

Science.gov (United States)

Schober, Patrick; Boer, Christa; Schwarte, Lothar A

2018-05-01

Correlation in the broadest sense is a measure of an association between variables. In correlated data, the change in the magnitude of 1 variable is associated with a change in the magnitude of another variable, either in the same (positive correlation) or in the opposite (negative correlation) direction. Most often, the term correlation is used in the context of a linear relationship between 2 continuous variables and expressed as Pearson product-moment correlation. The Pearson correlation coefficient is typically used for jointly normally distributed data (data that follow a bivariate normal distribution). For nonnormally distributed continuous data, for ordinal data, or for data with relevant outliers, a Spearman rank correlation can be used as a measure of a monotonic association. Both correlation coefficients are scaled such that they range from -1 to +1, where 0 indicates that there is no linear or monotonic association, and the relationship gets stronger and ultimately approaches a straight line (Pearson correlation) or a constantly increasing or decreasing curve (Spearman correlation) as the coefficient approaches an absolute value of 1. Hypothesis tests and confidence intervals can be used to address the statistical significance of the results and to estimate the strength of the relationship in the population from which the data were sampled. The aim of this tutorial is to guide researchers and clinicians in the appropriate use and interpretation of correlation coefficients.

Using the confidence interval confidently.

Science.gov (United States)

Hazra, Avijit

2017-10-01

Biomedical research is seldom done with entire populations but rather with samples drawn from a population. Although we work with samples, our goal is to describe and draw inferences regarding the underlying population. It is possible to use a sample statistic and estimates of error in the sample to get a fair idea of the population parameter, not as a single value, but as a range of values. This range is the confidence interval (CI) which is estimated on the basis of a desired confidence level. Calculation of the CI of a sample statistic takes the general form: CI = Point estimate ± Margin of error, where the margin of error is given by the product of a critical value (z) derived from the standard normal curve and the standard error of point estimate. Calculation of the standard error varies depending on whether the sample statistic of interest is a mean, proportion, odds ratio (OR), and so on. The factors affecting the width of the CI include the desired confidence level, the sample size and the variability in the sample. Although the 95% CI is most often used in biomedical research, a CI can be calculated for any level of confidence. A 99% CI will be wider than 95% CI for the same sample. Conflict between clinical importance and statistical significance is an important issue in biomedical research. Clinical importance is best inferred by looking at the effect size, that is how much is the actual change or difference. However, statistical significance in terms of P only suggests whether there is any difference in probability terms. Use of the CI supplements the P value by providing an estimate of actual clinical effect. Of late, clinical trials are being designed specifically as superiority, non-inferiority or equivalence studies. The conclusions from these alternative trial designs are based on CI values rather than the P value from intergroup comparison.

Robust Coefficients Alpha and Omega and Confidence Intervals with Outlying Observations and Missing Data: Methods and Software

Science.gov (United States)

Zhang, Zhiyong; Yuan, Ke-Hai

2016-01-01

Cronbach's coefficient alpha is a widely used reliability measure in social, behavioral, and education sciences. It is reported in nearly every study that involves measuring a construct through multiple items. With non-tau-equivalent items, McDonald's omega has been used as a popular alternative to alpha in the literature. Traditional estimation…

Robust Coefficients Alpha and Omega and Confidence Intervals with Outlying Observations and Missing Data Methods and Software

Science.gov (United States)

Zhang, Zhiyong; Yuan, Ke-Hai

2016-01-01

Cronbach's coefficient alpha is a widely used reliability measure in social, behavioral, and education sciences. It is reported in nearly every study that involves measuring a construct through multiple items. With non-tau-equivalent items, McDonald's omega has been used as a popular alternative to alpha in the literature. Traditional estimation…

Assessing Reliability of a Multi-Dimensional Scale by Coefficient Alpha

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Ivan Šerbetar

2016-04-01

Full Text Available The purpose of the study was to assess internal consistency by calculating coefficient alpha. It presents the variation in coefficient alpha, depending on questionnaire length and the homogeneity or heterogeneity of the questionnaire. The maximum possible value for coefficient alpha was also calculated by the item elimination method. The study included 99 children aged 10. The children completed The Athletic Coping Skills Inventory – 28 (ACSI-28; Smith et al., 1995, which contains seven constructs: coping with adversity, coachability, concentration, confidence and achievement motivation, goal setting and mental preparation, peaking under pressure and freedom from worry. The results confirmed that the values of the alpha coefficient vary depending on the number and composition of items and the sample size. In terms of item structure, homogeneous constructs yielded lower values for the alpha coefficient (in a range from .48 to .61 than the questionnaire with all the constructs (alpha = .79, despite higher inter-item correlations. In terms of the number of items, the longer test generated higher alpha coefficients (alpha = .79 than the shorter test (half-sets of items = .60, .73, .69, .70. A higher overall value (alpha = .83 can be achieved by item elimination.

Confidant Relations in Italy

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Jenny Isaacs

2015-02-01

Full Text Available Confidants are often described as the individuals with whom we choose to disclose personal, intimate matters. The presence of a confidant is associated with both mental and physical health benefits. In this study, 135 Italian adults responded to a structured questionnaire that asked if they had a confidant, and if so, to describe various features of the relationship. The vast majority of participants (91% reported the presence of a confidant and regarded this relationship as personally important, high in mutuality and trust, and involving minimal lying. Confidants were significantly more likely to be of the opposite sex. Participants overall were significantly more likely to choose a spouse or other family member as their confidant, rather than someone outside of the family network. Familial confidants were generally seen as closer, and of greater value, than non-familial confidants. These findings are discussed within the context of Italian culture.

Block Empirical Likelihood for Longitudinal Single-Index Varying-Coefficient Model

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Yunquan Song

2013-01-01

Full Text Available In this paper, we consider a single-index varying-coefficient model with application to longitudinal data. In order to accommodate the within-group correlation, we apply the block empirical likelihood procedure to longitudinal single-index varying-coefficient model, and prove a nonparametric version of Wilks’ theorem which can be used to construct the block empirical likelihood confidence region with asymptotically correct coverage probability for the parametric component. In comparison with normal approximations, the proposed method does not require a consistent estimator for the asymptotic covariance matrix, making it easier to conduct inference for the model's parametric component. Simulations demonstrate how the proposed method works.

The Distribution of the Product Explains Normal Theory Mediation Confidence Interval Estimation.

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Kisbu-Sakarya, Yasemin; MacKinnon, David P; Miočević, Milica

2014-05-01

The distribution of the product has several useful applications. One of these applications is its use to form confidence intervals for the indirect effect as the product of 2 regression coefficients. The purpose of this article is to investigate how the moments of the distribution of the product explain normal theory mediation confidence interval coverage and imbalance. Values of the critical ratio for each random variable are used to demonstrate how the moments of the distribution of the product change across values of the critical ratio observed in research studies. Results of the simulation study showed that as skewness in absolute value increases, coverage decreases. And as skewness in absolute value and kurtosis increases, imbalance increases. The difference between testing the significance of the indirect effect using the normal theory versus the asymmetric distribution of the product is further illustrated with a real data example. This article is the first study to show the direct link between the distribution of the product and indirect effect confidence intervals and clarifies the results of previous simulation studies by showing why normal theory confidence intervals for indirect effects are often less accurate than those obtained from the asymmetric distribution of the product or from resampling methods.

Sample size for estimation of the Pearson correlation coefficient in cherry tomato tests

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Bruno Giacomini Sari

2017-09-01

Full Text Available ABSTRACT: The aim of this study was to determine the required sample size for estimation of the Pearson coefficient of correlation between cherry tomato variables. Two uniformity tests were set up in a protected environment in the spring/summer of 2014. The observed variables in each plant were mean fruit length, mean fruit width, mean fruit weight, number of bunches, number of fruits per bunch, number of fruits, and total weight of fruits, with calculation of the Pearson correlation matrix between them. Sixty eight sample sizes were planned for one greenhouse and 48 for another, with the initial sample size of 10 plants, and the others were obtained by adding five plants. For each planned sample size, 3000 estimates of the Pearson correlation coefficient were obtained through bootstrap re-samplings with replacement. The sample size for each correlation coefficient was determined when the 95% confidence interval amplitude value was less than or equal to 0.4. Obtaining estimates of the Pearson correlation coefficient with high precision is difficult for parameters with a weak linear relation. Accordingly, a larger sample size is necessary to estimate them. Linear relations involving variables dealing with size and number of fruits per plant have less precision. To estimate the coefficient of correlation between productivity variables of cherry tomato, with a confidence interval of 95% equal to 0.4, it is necessary to sample 275 plants in a 250m² greenhouse, and 200 plants in a 200m² greenhouse.

We will be champions: Leaders' confidence in 'us' inspires team members' team confidence and performance.

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Fransen, K; Steffens, N K; Haslam, S A; Vanbeselaere, N; Vande Broek, G; Boen, F

2016-12-01

The present research examines the impact of leaders' confidence in their team on the team confidence and performance of their teammates. In an experiment involving newly assembled soccer teams, we manipulated the team confidence expressed by the team leader (high vs neutral vs low) and assessed team members' responses and performance as they unfolded during a competition (i.e., in a first baseline session and a second test session). Our findings pointed to team confidence contagion such that when the leader had expressed high (rather than neutral or low) team confidence, team members perceived their team to be more efficacious and were more confident in the team's ability to win. Moreover, leaders' team confidence affected individual and team performance such that teams led by a highly confident leader performed better than those led by a less confident leader. Finally, the results supported a hypothesized mediational model in showing that the effect of leaders' confidence on team members' team confidence and performance was mediated by the leader's perceived identity leadership and members' team identification. In conclusion, the findings of this experiment suggest that leaders' team confidence can enhance members' team confidence and performance by fostering members' identification with the team. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Raising Confident Kids

Science.gov (United States)

... First Aid & Safety Doctors & Hospitals Videos Recipes for Kids Kids site Sitio para niños How the Body ... Videos for Educators Search English Español Raising Confident Kids KidsHealth / For Parents / Raising Confident Kids What's in ...

Effect of retardation coefficient for radionuclide migration on assessment results of environmental impact

International Nuclear Information System (INIS)

Wang Zhiming

2004-01-01

Environmental impact report is an important content in enforcing environmental impact assessment system. Effect of retardation coefficient used in models of radionuclide migration in geological media on the calculated results of maximum concentration of calculated points at the lower reaches is discussed in this paper. It is shown from experimental results that the retardation coefficient is not a constant. And it is shown from calculated results that retardation coefficient obviously affect the calculated results of maximum concentration of calculated point at the lower reaches. Conservation level of the assessment results would considerably be affected, and hence confidence level of results would be affected if the aspects are not paid enough attention and solved. The paper suggests that retardation coefficient used in migration models should directly be obtained by measurement in the field or in column, rather than using the result derived from distribution coefficients according to some formula in order to prevent the nonconservative results

Sample Size Calculation for Estimating or Testing a Nonzero Squared Multiple Correlation Coefficient

Science.gov (United States)

Krishnamoorthy, K.; Xia, Yanping

2008-01-01

The problems of hypothesis testing and interval estimation of the squared multiple correlation coefficient of a multivariate normal distribution are considered. It is shown that available one-sided tests are uniformly most powerful, and the one-sided confidence intervals are uniformly most accurate. An exact method of calculating sample size to…

Diverse interpretations of confidence building

International Nuclear Information System (INIS)

Macintosh, J.

1998-01-01

This paper explores the variety of operational understandings associated with the term 'confidence building'. Collectively, these understandings constitute what should be thought of as a 'family' of confidence building approaches. This unacknowledged and generally unappreciated proliferation of operational understandings that function under the rubric of confidence building appears to be an impediment to effective policy. The paper's objective is to analyze these different understandings, stressing the important differences in their underlying assumptions. In the process, the paper underlines the need for the international community to clarify its collective thinking about what it means when it speaks of 'confidence building'. Without enhanced clarity, it will be unnecessarily difficult to employ the confidence building approach effectively due to the lack of consistent objectives and common operating assumptions. Although it is not the intention of this paper to promote a particular account of confidence building, dissecting existing operational understandings should help to identify whether there are fundamental elements that define what might be termed 'authentic' confidence building. Implicit here is the view that some operational understandings of confidence building may diverge too far from consensus models to count as meaningful members of the confidence building family. (author)

Chinese Management Research Needs Self-Confidence but not Over-confidence

DEFF Research Database (Denmark)

Li, Xin; Ma, Li

2018-01-01

Chinese management research aims to contribute to global management knowledge by offering rigorous and innovative theories and practical recommendations both for managing in China and outside. However, two seemingly opposite directions that researchers are taking could prove detrimental......-confidence, limiting theoretical innovation and practical relevance. Yet going in the other direction of overly indigenous research reflects over-confidence, often isolating the Chinese management research from the mainstream academia and at times, even becoming anti-science. A more integrated approach of conducting...... to the healthy development of Chinese management research. We argue that the two directions share a common ground that lies in the mindset regarding the confidence in the work on and from China. One direction of simply following the American mainstream on academic rigor demonstrates a lack of self...

The idiosyncratic nature of confidence.

Science.gov (United States)

Navajas, Joaquin; Hindocha, Chandni; Foda, Hebah; Keramati, Mehdi; Latham, Peter E; Bahrami, Bahador

2017-11-01

Confidence is the 'feeling of knowing' that accompanies decision making. Bayesian theory proposes that confidence is a function solely of the perceived probability of being correct. Empirical research has suggested, however, that different individuals may perform different computations to estimate confidence from uncertain evidence. To test this hypothesis, we collected confidence reports in a task where subjects made categorical decisions about the mean of a sequence. We found that for most individuals, confidence did indeed reflect the perceived probability of being correct. However, in approximately half of them, confidence also reflected a different probabilistic quantity: the perceived uncertainty in the estimated variable. We found that the contribution of both quantities was stable over weeks. We also observed that the influence of the perceived probability of being correct was stable across two tasks, one perceptual and one cognitive. Overall, our findings provide a computational interpretation of individual differences in human confidence.

Assessing sensitivity to change: choosing the appropriate change coefficient

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Stratford Paul W

2005-04-01

Full Text Available Abstract The past 20-years have seen the development and evaluation of many health status measures. Unlike the high standards demanded of those who conduct and report clinical intervention trials, the methodological rigor for studies examining the sensitivity to change of health status measures are less demanding. It is likely that the absence of a criterion standard for change in health status contributes to this shortcoming. To increase confidence in the results of these types of studies investigators have often calculated multiple change coefficients for the same patient sample. The purpose of this report is to identify the conflict that arises when multiple change coefficients are applied to the same patient sample. Three families of change coefficients based on different assumptions concerning the sample composition are identified: (1 the sample is homogeneous with respect to change; (2 subgroups of patients who truly change by different amounts exist; (3 individual patients, many of whom truly change by different amounts exist. We present several analyses which illustrate a major conceptual conflict: the signal (a measure's true ability to detect change for some of these coefficients appears in the noise term (measurement error of the others. We speculate that this dilemma occurs as a result of insufficient preparatory work such as pilot studies to establish the likely change characteristic of the patient population of interest. Uncertainty in the choice of change coefficient could be overcome by conducting pilot studies to ascertain the likely change characteristic of the population of interest. Once the population's change characteristic is identified, the choice of change coefficient should be clear.

A systematic review of maternal confidence for physiologic birth: characteristics of prenatal care and confidence measurement.

Science.gov (United States)

Avery, Melissa D; Saftner, Melissa A; Larson, Bridget; Weinfurter, Elizabeth V

2014-01-01

Because a focus on physiologic labor and birth has reemerged in recent years, care providers have the opportunity in the prenatal period to help women increase confidence in their ability to give birth without unnecessary interventions. However, most research has only examined support for women during labor. The purpose of this systematic review was to examine the research literature for information about prenatal care approaches that increase women's confidence for physiologic labor and birth and tools to measure that confidence. Studies were reviewed that explored any element of a pregnant woman's interaction with her prenatal care provider that helped build confidence in her ability to labor and give birth. Timing of interaction with pregnant women included during pregnancy, labor and birth, and the postpartum period. In addition, we looked for studies that developed a measure of women's confidence related to labor and birth. Outcome measures included confidence or similar concepts, descriptions of components of prenatal care contributing to maternal confidence for birth, and reliability and validity of tools measuring confidence. The search of MEDLINE, CINAHL, PsycINFO, and Scopus databases provided a total of 893 citations. After removing duplicates and articles that did not meet inclusion criteria, 6 articles were included in the review. Three relate to women's confidence for labor during the prenatal period, and 3 describe tools to measure women's confidence for birth. Research about enhancing women's confidence for labor and birth was limited to qualitative studies. Results suggest that women desire information during pregnancy and want to use that information to participate in care decisions in a relationship with a trusted provider. Further research is needed to develop interventions to help midwives and physicians enhance women's confidence in their ability to give birth and to develop a tool to measure confidence for use during prenatal care. © 2014 by

Sources of sport confidence, imagery type and performance among competitive athletes: the mediating role of sports confidence.

Science.gov (United States)

Levy, A R; Perry, J; Nicholls, A R; Larkin, D; Davies, J

2015-01-01

This study explored the mediating role of sport confidence upon (1) sources of sport confidence-performance relationship and (2) imagery-performance relationship. Participants were 157 competitive athletes who completed state measures of confidence level/sources, imagery type and performance within one hour after competition. Among the current sample, confirmatory factor analysis revealed appropriate support for the nine-factor SSCQ and the five-factor SIQ. Mediational analysis revealed that sport confidence had a mediating influence upon the achievement source of confidence-performance relationship. In addition, both cognitive and motivational imagery types were found to be important sources of confidence, as sport confidence mediated imagery type- performance relationship. Findings indicated that athletes who construed confidence from their own achievements and report multiple images on a more frequent basis are likely to benefit from enhanced levels of state sport confidence and subsequent performance.

The empirical Gaia G-band extinction coefficient

Science.gov (United States)

Danielski, C.; Babusiaux, C.; Ruiz-Dern, L.; Sartoretti, P.; Arenou, F.

2018-06-01

Context. The first Gaia data release unlocked the access to photometric information for 1.1 billion sources in the G-band. Yet, given the high level of degeneracy between extinction and spectral energy distribution for large passbands such as the Gaia G-band, a correction for the interstellar reddening is needed in order to exploit Gaia data. Aims: The purpose of this manuscript is to provide the empirical estimation of the Gaia G-band extinction coefficient kG for both the red giants and main sequence stars in order to be able to exploit the first data release DR1. Methods: We selected two samples of single stars: one for the red giants and one for the main sequence. Both samples are the result of a cross-match between Gaia DR1 and 2MASS catalogues; they consist of high-quality photometry in the G-, J- and KS-bands. These samples were complemented by temperature and metallicity information retrieved from APOGEE DR13 and LAMOST DR2 surveys, respectively. We implemented a Markov chain Monte Carlo method where we used (G - KS)0 versus Teff and (J - KS)0 versus (G - KS)0, calibration relations to estimate the extinction coefficient kG and we quantify its corresponding confidence interval via bootstrap resampling. We tested our method on samples of red giants and main sequence stars, finding consistent solutions. Results: We present here the determination of the Gaia extinction coefficient through a completely empirical method. Furthermore we provide the scientific community with a formula for measuring the extinction coefficient as a function of stellar effective temperature, the intrinsic colour (G - KS)0, and absorption.

A short note on jackknifing the concordance correlation coefficient.

Science.gov (United States)

Feng, Dai; Baumgartner, Richard; Svetnik, Vladimir

2014-02-10

Lin's concordance correlation coefficient (CCC) is a very popular scaled index of agreement used in applied statistics. To obtain a confidence interval (CI) for the estimate of CCC, jackknifing was proposed and shown to perform well in simulation as well as in applications. However, a theoretical proof of the validity of the jackknife CI for the CCC has not been presented yet. In this note, we establish a sufficient condition for using the jackknife method to construct the CI for the CCC. Copyright © 2013 John Wiley & Sons, Ltd.

Distinguishing highly confident accurate and inaccurate memory: insights about relevant and irrelevant influences on memory confidence.

Science.gov (United States)

Chua, Elizabeth F; Hannula, Deborah E; Ranganath, Charan

2012-01-01

It is generally believed that accuracy and confidence in one's memory are related, but there are many instances when they diverge. Accordingly it is important to disentangle the factors that contribute to memory accuracy and confidence, especially those factors that contribute to confidence, but not accuracy. We used eye movements to separately measure fluent cue processing, the target recognition experience, and relative evidence assessment on recognition confidence and accuracy. Eye movements were monitored during a face-scene associative recognition task, in which participants first saw a scene cue, followed by a forced-choice recognition test for the associated face, with confidence ratings. Eye movement indices of the target recognition experience were largely indicative of accuracy, and showed a relationship to confidence for accurate decisions. In contrast, eye movements during the scene cue raised the possibility that more fluent cue processing was related to higher confidence for both accurate and inaccurate recognition decisions. In a second experiment we manipulated cue familiarity, and therefore cue fluency. Participants showed higher confidence for cue-target associations for when the cue was more familiar, especially for incorrect responses. These results suggest that over-reliance on cue familiarity and under-reliance on the target recognition experience may lead to erroneous confidence.

Self-Confidence and Quality of Life in Women Undergoing Treatment for Breast Cancer

Science.gov (United States)

Shafaee, Fahimeh Sehati; Mirghafourvand, Mojgan; Harischi, Sepideh; Esfahani, Ali; Amirzehni, Jalileh

2018-01-01

Introduction: Quality of life is an important topic in the study of chronic diseases, especially cancer which can have a major effect on patient self-confidence. This study was conducted to determine quality of life and its relationship with self-confidence in women undergoing treatment for breast cancer. Methods: This cross-sectional, descriptive, analytical study was conducted in 2016 on 166 women with breast cancer undergoing treatment at Ghazi, Al-Zahra, International and/or Shams hospitals in Tabriz. The subjects were selected through convenience sampling. A personal-demographic questionnaire, the Cancer Quality of Life Questionnaire (QLQ-C30), and the Rosenberg Self-Esteem Scale (RSES) were completed for each patient. The data obtained were analyzed using independent t-tests, one-way ANOVA, multivariate linear regression and Pearson’s correlation coefficients. Findings: The mean total score of quality of life was 59.1±17.4, ranging from 0 to 100. The highest mean score was obtained in the cognitive subscale (74.9±23.8) and the lowest in the emotional subscale (51.4±21.1). The mean score for self-confidence was 0.3 with a standard deviation of 0.1, ranging from -1 to +1. There was a significant positive relationship between self-confidence and quality of life, except in three symptom subscales for diarrhea, constipation and loss of appetite (Pquality of life. Discussion: Given the significant relationship between quality of life and self-confidence, health care providers may need to pay special attention to women undergoing treatment for breast cancer and perform timely measures to maintain their belief in themselves. PMID:29582628

Self-confidence and metacognitive processes

Directory of Open Access Journals (Sweden)

Kleitman Sabina

2005-01-01

Full Text Available This paper examines the status of Self-confidence trait. Two studies strongly suggest that Self-confidence is a component of metacognition. In the first study, participants (N=132 were administered measures of Self-concept, a newly devised Memory and Reasoning Competence Inventory (MARCI, and a Verbal Reasoning Test (VRT. The results indicate a significant relationship between confidence ratings on the VRT and the Reasoning component of MARCI. The second study (N=296 employed an extensive battery of cognitive tests and several metacognitive measures. Results indicate the presence of robust Self-confidence and Metacognitive Awareness factors, and a significant correlation between them. Self-confidence taps not only processes linked to performance on items that have correct answers, but also beliefs about events that may never occur.

Bootstrap resampling: a powerful method of assessing confidence intervals for doses from experimental data

International Nuclear Information System (INIS)

Iwi, G.; Millard, R.K.; Palmer, A.M.; Preece, A.W.; Saunders, M.

1999-01-01

Bootstrap resampling provides a versatile and reliable statistical method for estimating the accuracy of quantities which are calculated from experimental data. It is an empirically based method, in which large numbers of simulated datasets are generated by computer from existing measurements, so that approximate confidence intervals of the derived quantities may be obtained by direct numerical evaluation. A simple introduction to the method is given via a detailed example of estimating 95% confidence intervals for cumulated activity in the thyroid following injection of 99m Tc-sodium pertechnetate using activity-time data from 23 subjects. The application of the approach to estimating confidence limits for the self-dose to the kidney following injection of 99m Tc-DTPA organ imaging agent based on uptake data from 19 subjects is also illustrated. Results are then given for estimates of doses to the foetus following administration of 99m Tc-sodium pertechnetate for clinical reasons during pregnancy, averaged over 25 subjects. The bootstrap method is well suited for applications in radiation dosimetry including uncertainty, reliability and sensitivity analysis of dose coefficients in biokinetic models, but it can also be applied in a wide range of other biomedical situations. (author)

Increasing Product Confidence-Shifting Paradigms.

Science.gov (United States)

Phillips, Marla; Kashyap, Vishal; Cheung, Mee-Shew

2015-01-01

Leaders in the pharmaceutical, medical device, and food industries expressed a unilateral concern over product confidence throughout the total product lifecycle, an unsettling fact for these leaders to manage given that their products affect the lives of millions of people each year. Fueled by the heparin incident of intentional adulteration in 2008, initial efforts for increasing product confidence were focused on improving the confidence of incoming materials, with a belief that supplier performance must be the root cause. As in the heparin case, concern over supplier performance extended deep into the supply chain to include suppliers of the suppliers-which is often a blind spot for pharmaceutical, device, and food manufacturers. Resolved to address the perceived lack of supplier performance, these U.S. Food and Drug Administration (FDA)-regulated industries began to adopt the supplier relationship management strategy, developed by the automotive industry, that emphasizes "management" of suppliers for the betterment of the manufacturers. Current product and supplier management strategies, however, have not led to a significant improvement in product confidence. As a result of the enduring concern by industry leaders over the lack of product confidence, Xavier University launched the Integrity of Supply Initiative in 2012 with a team of industry leaders and FDA officials. Through a methodical research approach, data generated by the pharmaceutical, medical device, and food manufacturers surprisingly pointed to themselves as a source of the lack of product confidence, and revealed that manufacturers either unknowingly increase the potential for error or can control/prevent many aspects of product confidence failure. It is only through this paradigm shift that manufacturers can work collaboratively with their suppliers as equal partners, instead of viewing their suppliers as "lesser" entities needing to be controlled. The basis of this shift provides manufacturers

Distinguishing highly confident accurate and inaccurate memory: insights about relevant and irrelevant influences on memory confidence

OpenAIRE

Chua, Elizabeth F.; Hannula, Deborah E.; Ranganath, Charan

2012-01-01

It is generally believed that accuracy and confidence in one’s memory are related, but there are many instances when they diverge. Accordingly, it is important to disentangle the factors which contribute to memory accuracy and confidence, especially those factors that contribute to confidence, but not accuracy. We used eye movements to separately measure fluent cue processing, the target recognition experience, and relative evidence assessment on recognition confidence and accuracy. Eye movem...

An experimental determination of the drag coefficient of a Mens 8+ racing shell.

Science.gov (United States)

Buckmann, James G; Harris, Samuel D

2014-01-01

This study centered around an experimental analysis of a Mens Lightweight Eight racing shell and, specifically, determining an approximation for the drag coefficient. A testing procedure was employed that used a Global Positioning System (GPS) unit in order to determine the acceleration and drag force on the shell, and through calculations yield a drag coefficient. The testing was run over several days in numerous conditions, and a 95% confidence interval was established to capture the results. The results obtained, over these varying trials, maintained a successful level of consistency. The significance of this study transcends the determination an approximation for the drag coefficient of the racing shell; it defined a successful means of quantifying performance of the shell itself. The testing procedures outlined in the study represent a uniform means of evaluating the factors that influence drag on the shell, and thus influence speed.

The Model Confidence Set

DEFF Research Database (Denmark)

Hansen, Peter Reinhard; Lunde, Asger; Nason, James M.

The paper introduces the model confidence set (MCS) and applies it to the selection of models. A MCS is a set of models that is constructed such that it will contain the best model with a given level of confidence. The MCS is in this sense analogous to a confidence interval for a parameter. The MCS......, beyond the comparison of models. We apply the MCS procedure to two empirical problems. First, we revisit the inflation forecasting problem posed by Stock and Watson (1999), and compute the MCS for their set of inflation forecasts. Second, we compare a number of Taylor rule regressions and determine...... the MCS of the best in terms of in-sample likelihood criteria....

Confidence limits for regional cerebral blood flow values obtained with circular positron system, using krypton-77

International Nuclear Information System (INIS)

Meyer, E.; Yamamoto, Y.L.; Thompson, C.J.

1978-01-01

The 90% confidence limits have been determined for regional cerebral blood flow (rCBF) values obtained in each cm 2 of a cross section of the human head after inhalation of radioactive krypton-77, using the MNI circular positron emission tomography system (Positome). CBF values for small brain tissue elements are calculated by linear regression analysis on the semi-logarithmically transformed clearance curve. A computer program displays CBF values and their estimated error in numeric and gray scale forms. The following typical results have been obtained on a control subject: mean CBF in the entire cross section of the head: 54.6 + - 5 ml/min/100 g tissue, rCBF for small area of frontal gray matter: 75.8 + - 9 ml/min/100 g tissue. Confidence intervals for individual rCBF values varied between + - 13 and + - 55% except for areas pertaining to the ventricular system where particularly poor statistics have been obtained. Knowledge of confidence limits for rCBF values improves their diagnostic significance, particularly with respect to the assessment of reduced rCBF in stroke patients. A nomogram for convenient determination of 90% confidence limits for slope values obtained in linear regression analysis has been designed with the number of fitted points (n) and the correlation coefficient (r) as parameters. (author)

Evaluation of temperature coefficients of reactivity for 233U--thorium fueled HTGR lattices. Final report

International Nuclear Information System (INIS)

Newman, D.F.; Leonard, B.R. Jr.; Trapp, T.J.; Gore, B.F.; Kottwitz, D.A.; Thompson, J.K.; Purcell, W.L.; Stewart, K.B.

1977-05-01

A comparison of calculated and measured neutron multiplication factors as a function of temperature was made for three graphite-moderated lattices in the High Temperature Lattice Test Reactor (HTLTR) using 233 UO 2 --ThO 2 fuels in varying amounts and configurations. Correlation of neutronic analysis methods and cross section data with the experimental measurements forms the basis for assessing the accuracy of the methods and data and developing confidence in the ability to predict the temperature coefficient of reactivity for various High Temperature Gas-Cooled Reactor (HTGR) conditions in which 233 U and thorium are present in the fuel. The calculated values of k/sub infinity/(T) were correlated with measured values using two least-squares-fitted correlation coefficients: (1) a normalization factor, and (2) a temperature coefficient bias factor. These correlations indicate the existence of a negative (nonconservative) bias in temperature coefficients of reactivity calculated using ENDF/B-IV cross section data

Evaluation of error bands and confidence limits for thermal measurements in the CFTL bundle

International Nuclear Information System (INIS)

Childs, K.W.; Sanders, J.P.; Conklin, J.C.

1979-01-01

Surface cladding temperatures for the fuel rod simulators in the Core Flow Test Loop (CFTL) must be inferred from a measurement at a thermocouple junction within the rod. This step requires the evaluation of the thermal field within the rod based on known parameters such as heat generation rate, dimensional tolerances, thermal properties, and contact coefficients. Uncertainties in the surface temperature can be evaluated by assigning error bands to each of the parameters used in the calculation. A statistical method has been employed to establish the confidence limits for the surface temperature from a combination of the standard deviations of the important parameters. This method indicates that for a CFTL fuel rod simulator with a total power of 38 kW and a ratio of maximum to average axial power of 1.21, the 95% confidence limit for the calculated surface temperature is +- 45 0 C at the midpoint of the rod

Confidence in critical care nursing.

Science.gov (United States)

Evans, Jeanne; Bell, Jennifer L; Sweeney, Annemarie E; Morgan, Jennifer I; Kelly, Helen M

2010-10-01

The purpose of the study was to gain an understanding of the nursing phenomenon, confidence, from the experience of nurses in the nursing subculture of critical care. Leininger's theory of cultural care diversity and universality guided this qualitative descriptive study. Questions derived from the sunrise model were used to elicit nurses' perspectives about cultural and social structures that exist within the critical care nursing subculture and the influence that these factors have on confidence. Twenty-eight critical care nurses from a large Canadian healthcare organization participated in semistructured interviews about confidence. Five themes arose from the descriptions provided by the participants. The three themes, tenuously navigating initiation rituals, deliberately developing holistic supportive relationships, and assimilating clinical decision-making rules were identified as social and cultural factors related to confidence. The remaining two themes, preserving a sense of security despite barriers and accommodating to diverse challenges, were identified as environmental factors related to confidence. Practice and research implications within the culture of critical care nursing are discussed in relation to each of the themes.

Professional confidence: a concept analysis.

Science.gov (United States)

Holland, Kathlyn; Middleton, Lyn; Uys, Leana

2012-03-01

Professional confidence is a concept that is frequently used and or implied in occupational therapy literature, but often without specifying its meaning. Rodgers's Model of Concept Analysis was used to analyse the term "professional confidence". Published research obtained from a federated search in four health sciences databases was used to inform the concept analysis. The definitions, attributes, antecedents, and consequences of professional confidence as evidenced in the literature are discussed. Surrogate terms and related concepts are identified, and a model case of the concept provided. Based on the analysis, professional confidence can be described as a dynamic, maturing personal belief held by a professional or student. This includes an understanding of and a belief in the role, scope of practice, and significance of the profession, and is based on their capacity to competently fulfil these expectations, fostered through a process of affirming experiences. Developing and fostering professional confidence should be nurtured and valued to the same extent as professional competence, as the former underpins the latter, and both are linked to professional identity.

Regional Competition for Confidence: Features of Formation

Directory of Open Access Journals (Sweden)

Irina Svyatoslavovna Vazhenina

2016-09-01

Full Text Available The increase in economic independence of the regions inevitably leads to an increase in the quality requirements of the regional economic policy. The key to successful regional policy, both during its development and implementation, is the understanding of the necessity of gaining confidence (at all levels, and the inevitable participation in the competition for confidence. The importance of confidence in the region is determined by its value as a competitive advantage in the struggle for partners, resources and tourists, and attracting investments. In today’s environment the focus of governments, regions and companies on long-term cooperation is clearly expressed, which is impossible without a high level of confidence between partners. Therefore, the most important competitive advantages of territories are intangible assets such as an attractive image and a good reputation, which builds up confidence of the population and partners. The higher the confidence in the region is, the broader is the range of potential partners, the larger is the planning horizon of long-term concerted action, the better are the chances of acquiring investment, the higher is the level of competitive immunity of the territories. The article defines competition for confidence as purposeful behavior of a market participant in economic environment, aimed at acquiring specific intangible competitive advantage – the confidence of the largest possible number of other market actors. The article also highlights the specifics of confidence as a competitive goal, presents factors contributing to the destruction of confidence, proposes a strategy to fight for confidence as a program of four steps, considers the factors which integrate regional confidence and offers several recommendations for the establishment of effective regional competition for confidence

Impact of erectile dysfunction on confidence, self-esteem and relationship satisfaction after 9 months of sildenafil citrate treatment.

Science.gov (United States)

Althof, Stanley E; O'Leary, Michael P; Cappelleri, Joseph C; Crowley, Arthur R; Tseng, Li-Jung; Collins, Suzanne

2006-11-01

The first double-blind, placebo controlled trial in the United States of the Self-Esteem And Relationship questionnaire revealed that treatment with sildenafil citrate improves erectile function and measures of quality of life in men with erectile dysfunction. We investigated long-term improvement, and correlations between improved erectile function and confidence, self-esteem and sexual relationship satisfaction in men with erectile dysfunction. This was a 36-week open label extension of the double-blind, placebo controlled trial. The blind was not broken. Patients were 18 years or older with clinically diagnosed erectile dysfunction. Erectile function was assessed using the International Index of Erectile Function. Self-esteem, confidence and relationship satisfaction were assessed using the Self-Esteem And Relationship questionnaire. Correlations were determined using Pearson's product moment coefficients. A total of 204 participants were enrolled in the open label extension, including 108 on placebo and 96 on sildenafil. In men who received placebo in the double-blind, placebo controlled phase mean erectile function scores and self-esteem, confidence and relationship satisfaction scores were increased significantly at week 36 of the open label extension (p self-esteem, confidence and relationship satisfaction were strong and positive (p self-esteem, confidence and relationship satisfaction. Following an initial 12 weeks of double-blind, placebo controlled sildenafil therapy for erectile dysfunction improvements were sustained an additional 9 months. Positive correlations between erectile function, and self-esteem, confidence and relationship satisfaction suggest that improved erectile quality can improve long-term psychosocial quality of life.

Wind shear coefficients and their effect on energy production

International Nuclear Information System (INIS)

Rehman, Shafiqur; Al-Abbadi, Naif M.

2005-01-01

This paper provides realistic values of wind shear coefficients calculated using measured values of wind speed at 20, 30 and 40 m above the ground for the first time in Saudi Arabia in particular and, to the best of the authors' knowledge, in the Gulf region in general. The paper also presents air density values calculated using the measured air temperature and surface pressure and the effects of wind shear factor on energy production from wind machines of different sizes. The measured data used in the study covered a period of almost three years between June 17, 1995 and December 1998. An overall mean value of wind shear coefficient of 0.194 can be used with confidence to calculate the wind speed at different heights if measured values are known at one height. The study showed that the wind shear coefficient is significantly influenced by seasonal and diurnal changes. Hence, for precise estimations of wind speed at a height, both monthly or seasonal and hourly or night time and day time average values of wind shear coefficient must be used. It is suggested that the wind shear coefficients must be calculated either (i) using long term average values of wind speed at different heights or (ii) using those half hourly mean values of wind speed for which the wind shear coefficient lies in the range 0 and 0.51. The air density, calculated using measured temperature and pressure was found to be 1.18 kg/m 3 . The air density values were also found to vary with the season of the year and hour of the day, and hence, care must be taken when precise calculations are to be made. The air density values, as shown in this paper, have no significant variation with height. The energy production analysis showed that the actual wind shear coefficient presented in this paper produced 6% more energy compared to that obtained using the 1/7 power law. Similarly, higher plant capacity factors were obtained with the wind shear factor of 0.194 compared to that with 0.143

Correlation Between Minimum Apparent Diffusion Coefficient (ADCmin) and Tumor Cellularity: A Meta-analysis.

Science.gov (United States)

Surov, Alexey; Meyer, Hans Jonas; Wienke, Andreas

2017-07-01

Diffusion-weighted imaging (DWI) is a magnetic resonance imaging (MRI) technique based on measure of water diffusion that can provide information about tissue microstructure, especially about cell count. Increase of cell density induces restriction of water diffusion and decreases apparent diffusion coefficient (ADC). ADC can be divided into three sub-parameters: ADC minimum or ADC min , mean ADC or ADC mean and ADC maximum or ADC max Some studies have suggested that ADC min shows stronger correlations with cell count in comparison to other ADC fractions and may be used as a parameter for estimation of tumor cellularity. The aim of the present meta-analysis was to summarize correlation coefficients between ADC min and cellularity in different tumors based on large patient data. For this analysis, MEDLINE database was screened for associations between ADC and cell count in different tumors up to September 2016. For this work, only data regarding ADC min were included. Overall, 12 publications with 317 patients were identified. Spearman's correlation coefficient was used to analyze associations between ADC min and cellularity. The reported Pearson correlation coefficients in some publications were converted into Spearman correlation coefficients. The pooled correlation coefficient for all included studies was ρ=-0.59 (95% confidence interval (CI)=-0.72 to -0.45), heterogeneity Tau 2 =0.04 (pcorrelated moderately with tumor cellularity. The calculated correlation coefficient is not stronger in comparison to the reported coefficient for ADC mean and, therefore, ADC min does not represent a better means to reflect cellularity. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

[Sources of leader's confidence in organizations].

Science.gov (United States)

Ikeda, Hiroshi; Furukawa, Hisataka

2006-04-01

The purpose of this study was to examine the sources of confidence that organization leaders had. As potential sources of the confidence, we focused on fulfillment of expectations made by self and others, reflection on good as well as bad job experiences, and awareness of job experiences in terms of commonality, differentiation, and multiple viewpoints. A questionnaire was administered to 170 managers of Japanese companies. Results were as follows: First, confidence in leaders was more strongly related to fulfillment of expectations made by self and others than reflection on and awareness of job experiences. Second, the confidence was weakly related to internal processing of job experiences, in the form of commonality awareness and reflection on good job experiences. And finally, years of managerial experiences had almost no relation to the confidence. These findings suggested that confidence in leaders was directly acquired from fulfillment of expectations made by self and others, rather than indirectly through internal processing of job experiences. Implications of the findings for leadership training were also discussed.

Confidence Intervals for Omega Coefficient: Proposal for Calculus.

Science.gov (United States)

Ventura-León, José Luis

2018-01-01

La confiabilidad es entendida como una propiedad métrica de las puntuaciones de un instrumento de medida. Recientemente se viene utilizando el coeficiente omega (ω) para la estimación de la confiabilidad. No obstante, la medición nunca es exacta por la influencia del error aleatorio, por esa razón es necesario calcular y reportar el intervalo de confianza (IC) que permite encontrar en valor verdadero en un rango de medida. En ese contexto, el artículo plantea una forma de estimar el IC mediante el método de bootstrap para facilitar este procedimiento se brindan códigos de R (un software de acceso libre) para que puedan realizarse los cálculos de una forma amigable. Se espera que el artículo sirva de ayuda a los investigadores de ámbito de salud.

Confidence-building and Canadian leadership

International Nuclear Information System (INIS)

Cleminson, F.R.

1998-01-01

Confidence-building has come into its own as a 'tool of choice' in facilitating the non-proliferation, arms control and disarmament (NACD) agenda, whether regional or global. From the Middle East Peace Process (MEPP) to the ASEAN Intersessional Group on Confidence-Building (ARF ISG on CBMS), confidence-building has assumed a central profile in regional terms. In the Four Power Talks begun in Geneva on December 9, 1997, the United States identified confidence-building as one of two subject areas for initial discussion as part of a structured peace process between North and South Korea. Thus, with CBMs assuming such a high profile internationally, it seems prudent for Canadians to pause and take stock of the significant role which Canada has already played in the conceptual development of the process over the last two decades. Since the Helsinki accords of 1975, Canada has developed a significant expertise in this area through an unbroken series of original, basic research projects. These have contributed to defining the process internationally from concept to implementation. Today, these studies represent a solid and unique Departmental investment in basic research from which to draw in meeting Canada's current commitments to multilateral initiatives in the area of confidence-building and to provide a 'step up' in terms of future-oriented leadership. (author)

On-line confidence monitoring during decision making.

Science.gov (United States)

Dotan, Dror; Meyniel, Florent; Dehaene, Stanislas

2018-02-01

Humans can readily assess their degree of confidence in their decisions. Two models of confidence computation have been proposed: post hoc computation using post-decision variables and heuristics, versus online computation using continuous assessment of evidence throughout the decision-making process. Here, we arbitrate between these theories by continuously monitoring finger movements during a manual sequential decision-making task. Analysis of finger kinematics indicated that subjects kept separate online records of evidence and confidence: finger deviation continuously reflected the ongoing accumulation of evidence, whereas finger speed continuously reflected the momentary degree of confidence. Furthermore, end-of-trial finger speed predicted the post-decisional subjective confidence rating. These data indicate that confidence is computed on-line, throughout the decision process. Speed-confidence correlations were previously interpreted as a post-decision heuristics, whereby slow decisions decrease subjective confidence, but our results suggest an adaptive mechanism that involves the opposite causality: by slowing down when unconfident, participants gain time to improve their decisions. Copyright © 2017 Elsevier B.V. All rights reserved.

How do regulators measure public confidence?

International Nuclear Information System (INIS)

Schmitt, A.; Besenyei, E.

2006-01-01

The conclusions and recommendations of this session can be summarized this way. - There are some important elements of confidence: visibility, satisfaction, credibility and reputation. The latter can consist of trust, positive image and knowledge of the role the organisation plays. A good reputation is hard to achieve but easy to lose. - There is a need to define what public confidence is and what to measure. The difficulty is that confidence is a matter of perception of the public, so what we try to measure is the perception. - It is controversial how to take into account the results of confidence measurement because of the influence of the context. It is not an exact science, results should be examined cautiously and surveys should be conducted frequently, at least every two years. - Different experiences were explained: - Quantitative surveys - among the general public or more specific groups like the media; - Qualitative research - with test groups and small panels; - Semi-quantitative studies - among stakeholders who have regular contracts with the regulatory body. It is not clear if the results should be shared with the public or just with other authorities and governmental organisations. - Efforts are needed to increase visibility, which is a prerequisite for confidence. - A practical example of organizing an emergency exercise and an information campaign without taking into account the real concerns of the people was given to show how public confidence can be decreased. - We learned about a new method - the so-called socio-drama - which addresses another issue also connected to confidence - the notion of understanding between stakeholders around a nuclear site. It is another way of looking at confidence in a more restricted group. (authors)

The Great Recession and confidence in homeownership

OpenAIRE

Anat Bracha; Julian Jamison

2013-01-01

Confidence in homeownership shifts for those who personally experienced real estate loss during the Great Recession. Older Americans are confident in the value of homeownership. Younger Americans are less confident.

Discharge Coefficient of Rectangular Short-Crested Weir with Varying Slope Coefficients

Directory of Open Access Journals (Sweden)

Yuejun Chen

2018-02-01

Full Text Available Rectangular short-crested weirs are widely used for simple structure and high discharge capacity. As one of the most important and influential factors of discharge capacity, side slope can improve the hydraulic characteristics of weirs at special conditions. In order to systemically study the effects of upstream and downstream slope coefficients S1 and S2 on overflow discharge coefficient in a rectangular short-crested weir the Volume of Fluid (VOF method and the Renormalization Group (RNG κ-ε turbulence model are used. In this study, the slope coefficient ranges from V to 3H:1V and each model corresponds to five total energy heads of H0 ranging from 8.0 to 24.0 cm. Comparisons of discharge coefficients and free surface profiles between simulated and laboratory results display a good agreement. The simulated results show that the difference of discharge coefficients will decrease with upstream slopes and increase with downstream slopes as H0 increases. For a given H0, the discharge coefficient has a convex parabolic relation with S1 and a piecewise linearity relation with S2. The maximum discharge coefficient is always obtained at S2 = 0.8. There exists a difference between upstream and downstream slope coefficients in the influence range of free surface curvatures. Furthermore, a proposed discharge coefficient equation by nonlinear regression is a function of upstream and downstream slope coefficients.

Confidence-building and Canadian leadership

Energy Technology Data Exchange (ETDEWEB)

Cleminson, F.R. [Dept. of Foreign Affairs and International Trade, Verification, Non-Proliferation, Arms Control and Disarmament Div (IDA), Ottawa, Ontario (Canada)

1998-07-01

Confidence-building has come into its own as a 'tool of choice' in facilitating the non-proliferation, arms control and disarmament (NACD) agenda, whether regional or global. From the Middle East Peace Process (MEPP) to the ASEAN Intersessional Group on Confidence-Building (ARF ISG on CBMS), confidence-building has assumed a central profile in regional terms. In the Four Power Talks begun in Geneva on December 9, 1997, the United States identified confidence-building as one of two subject areas for initial discussion as part of a structured peace process between North and South Korea. Thus, with CBMs assuming such a high profile internationally, it seems prudent for Canadians to pause and take stock of the significant role which Canada has already played in the conceptual development of the process over the last two decades. Since the Helsinki accords of 1975, Canada has developed a significant expertise in this area through an unbroken series of original, basic research projects. These have contributed to defining the process internationally from concept to implementation. Today, these studies represent a solid and unique Departmental investment in basic research from which to draw in meeting Canada's current commitments to multilateral initiatives in the area of confidence-building and to provide a 'step up' in terms of future-oriented leadership. (author)

Goal orientation as a motivation model and self-confidence among tennis players of different levels of success

Directory of Open Access Journals (Sweden)

Lepir Duško

2014-01-01

Full Text Available The goal of this research was to determine differences between the successful and less successful tennis players regarding their goal orientation and self-confidence, as well as to examine the correlation between these two psychological constructs. Active male tennis players (N=40, ranked on the senior list of the Tennis Federation of Austria, age 18 to 26, filled in the TEOSQ-D1 questionnaire (Würth, Alfermann and Saborowski, 1999, and CSI questionnaire (Vealey, 1986, just before the national senior championship of Austria. After categorising a 'successful tennis player' as one ranked in top 100 (N=20, and a 'less successful' one as ranked outside top 100 (N=20, analyses of their differences concerning goal orientation and self-confidence were conducted by means of the T-test, but no statistically significant differences were found for any scale. Pearson's coefficient for the entire sample showed that task orientation correlate significantly with the sport confidence trait (r= 0,451; Sig.= 0,05, and to a certain extent with sport-confidence as a state (r= 0,387; Sig.= 0,092, but that correlation is not statistically significant at the level Sig.< 0,05. For the result/ego scale orientation, there were no significant correlations with sporting-confidence. Guidelines for future research are based on the development of a more adequate system for evaluation of success in sport, and also on increasing of sample size. This could be very helpful for making more reliable conclusions about the influence of goal orientation preference on sport-confidence and sport success, which could justify the utilization of this psychological construct for practical purposes.

Monte Carlo simulation of parameter confidence intervals for non-linear regression analysis of biological data using Microsoft Excel.

Science.gov (United States)

Lambert, Ronald J W; Mytilinaios, Ioannis; Maitland, Luke; Brown, Angus M

2012-08-01

This study describes a method to obtain parameter confidence intervals from the fitting of non-linear functions to experimental data, using the SOLVER and Analysis ToolPaK Add-In of the Microsoft Excel spreadsheet. Previously we have shown that Excel can fit complex multiple functions to biological data, obtaining values equivalent to those returned by more specialized statistical or mathematical software. However, a disadvantage of using the Excel method was the inability to return confidence intervals for the computed parameters or the correlations between them. Using a simple Monte-Carlo procedure within the Excel spreadsheet (without recourse to programming), SOLVER can provide parameter estimates (up to 200 at a time) for multiple 'virtual' data sets, from which the required confidence intervals and correlation coefficients can be obtained. The general utility of the method is exemplified by applying it to the analysis of the growth of Listeria monocytogenes, the growth inhibition of Pseudomonas aeruginosa by chlorhexidine and the further analysis of the electrophysiological data from the compound action potential of the rodent optic nerve. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Re-evaluation of SiC permeation coefficients at high temperatures

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Yasushi, E-mail: yama3707@kansai-u.ac.jp [Faculty of Engineering Science, Kansai Univ., Yamate-cho, Suita, Osaka 564-8680 (Japan); Murakami, Yuichiro; Yamaguchi, Hirosato; Yamamoto, Takehiro; Yonetsu, Daigo [Faculty of Engineering Science, Kansai Univ., Yamate-cho, Suita, Osaka 564-8680 (Japan); Noborio, Kazuyuki [Hydrogen Isotope Research Center, Univ. of Toyama, Toyama, Toyama 930-8555 (Japan); Konishi, Satoshi [Institute of Advanced Energy, Kyoto Univ., Gokasho, Uji, Kyoto 611-0011 (Japan)

2016-11-01

Highlights: • The deuterium permeation coefficients of CVD-SiC at 600–950 °C were evaluated. • The wraparound flow was reduced to less than 1/100th of the permeation flow. • CVD-SiC materials are very effective as hydrogen isotope permeation barriers. - Abstract: Since 2007, our group has studied the deuterium permeation and diffusion coefficients for SiC materials at temperatures above 600 °C as a means of evaluating the tritium inventory and permeation in fusion blankets. During such measurements, control and evaluation of the wraparound flow through the sample holder are important, and so the heated sample holder is enclosed by a glass tube and kept under vacuum during experimental trials. However, detailed studies regarding the required degree of vacuum based on model calculations have shown that the wraparound flow is much larger than expected, and so can affect measurements at high temperatures. We therefore modified the measurement apparatus based on calculations involving reduced pressure in the glass tube, and are now confident that the measurement error is only several percent, even at 950 °C. In this paper, recent experimental results obtained with a chemical vapor deposition (CVD)-SiC sample over the temperature range of 600–950 °C are presented, showing that the permeation coefficient for CVD-SiC is more than three orders of magnitude smaller than that for stainless steel (SS316) at 600 °C, and that at 950 °C, the coefficient for CVD-SiC is almost equal to that for SUS316 at 550 °C.

The reliability of prayer-based self-efficacy scale to assess self-confidence of Muslims with low back pain.

Science.gov (United States)

Al-Obaidi, Saud; Wall, James C; Mulekar, Madhuri S; Al-Mutairie, Rebecca

2012-06-01

Low back pain (LBP) may challenge an individual's self-confidence to perform usual daily activities such as Islamic daily prayer. Existing self-efficacy scales may not be appropriate to assess individual's self-confidence to perform Islamic prayers. This study aimed to develop a scale to assess self-confidence to prepare and perform Islamic prayer in the presence of LBP, the Islamic Prayer-based Self-efficacy Scale (IpbSeS), and to determine its consistency. The IpbSeS consists of three parts: pre-prayer preparation, getting to and from the mosque, and positions and movements during prayer. On a scale of 0 to 6, 0 indicates 'not at all confident' and 6 'fully confident'. Sixty individuals with LBP gave their responses on two different visits. Pain intensity was assessed by the Visual Analogue Scale (VAS), and the pain intensity changes were assessed using a seven-point global patient rating scale. Descriptive statistics, Pearson's correlation coefficient, Wilcoxon test and t-test were used in the analysis (alpha set at 0.05). VAS scores did not differ significantly between visits. No association was found between VAS and age (r = 0.039, p = 0.77) and between VAS and body mass index (BMI; r = 0.06, p = 0. 67). All 28 questions have consistent responses on two visits (0.75 ≤ r ≤ 0.99, p Muslims in the presence of LBP to pray. Copyright © 2011 John Wiley & Sons, Ltd.

SPSS and SAS programs for comparing Pearson correlations and OLS regression coefficients.

Science.gov (United States)

Weaver, Bruce; Wuensch, Karl L

2013-09-01

Several procedures that use summary data to test hypotheses about Pearson correlations and ordinary least squares regression coefficients have been described in various books and articles. To our knowledge, however, no single resource describes all of the most common tests. Furthermore, many of these tests have not yet been implemented in popular statistical software packages such as SPSS and SAS. In this article, we describe all of the most common tests and provide SPSS and SAS programs to perform them. When they are applicable, our code also computes 100 × (1 - α)% confidence intervals corresponding to the tests. For testing hypotheses about independent regression coefficients, we demonstrate one method that uses summary data and another that uses raw data (i.e., Potthoff analysis). When the raw data are available, the latter method is preferred, because use of summary data entails some loss of precision due to rounding.

Confidence Leak in Perceptual Decision Making.

Science.gov (United States)

Rahnev, Dobromir; Koizumi, Ai; McCurdy, Li Yan; D'Esposito, Mark; Lau, Hakwan

2015-11-01

People live in a continuous environment in which the visual scene changes on a slow timescale. It has been shown that to exploit such environmental stability, the brain creates a continuity field in which objects seen seconds ago influence the perception of current objects. What is unknown is whether a similar mechanism exists at the level of metacognitive representations. In three experiments, we demonstrated a robust intertask confidence leak-that is, confidence in one's response on a given task or trial influencing confidence on the following task or trial. This confidence leak could not be explained by response priming or attentional fluctuations. Better ability to modulate confidence leak predicted higher capacity for metacognition as well as greater gray matter volume in the prefrontal cortex. A model based on normative principles from Bayesian inference explained the results by postulating that observers subjectively estimate the perceptual signal strength in a stable environment. These results point to the existence of a novel metacognitive mechanism mediated by regions in the prefrontal cortex. © The Author(s) 2015.

Targeting Low Career Confidence Using the Career Planning Confidence Scale

Science.gov (United States)

McAuliffe, Garrett; Jurgens, Jill C.; Pickering, Worth; Calliotte, James; Macera, Anthony; Zerwas, Steven

2006-01-01

The authors describe the development and validation of a test of career planning confidence that makes possible the targeting of specific problem issues in employment counseling. The scale, developed using a rational process and the authors' experience with clients, was tested for criterion-related validity against 2 other measures. The scale…

Confidence Building Strategies in the Public Schools.

Science.gov (United States)

Achilles, C. M.; And Others

1985-01-01

Data from the Phi Delta Kappa Commission on Public Confidence in Education indicate that "high-confidence" schools make greater use of marketing and public relations strategies. Teacher attitudes were ranked first and administrator attitudes second by 409 respondents for both gain and loss of confidence in schools. (MLF)

Confidence rating of marine eutrophication assessments

DEFF Research Database (Denmark)

Murray, Ciarán; Andersen, Jesper Harbo; Kaartokallio, Hermanni

2011-01-01

of the 'value' of the indicators on which the primary assessment is made. Such secondary assessment of confidence represents a first step towards linking status classification with information regarding their accuracy and precision and ultimately a tool for improving or targeting actions to improve the health......This report presents the development of a methodology for assessing confidence in eutrophication status classifications. The method can be considered as a secondary assessment, supporting the primary assessment of eutrophication status. The confidence assessment is based on a transparent scoring...

Computation of Clebsch-Gordan and Gaunt coefficients using binomial coefficients

International Nuclear Information System (INIS)

Guseinov, I.I.; Oezmen, A.; Atav, Ue

1995-01-01

Using binomial coefficients the Clebsch-Gordan and Gaunt coefficients were calculated for extremely large quantum numbers. The main advantage of this approach is directly calculating these coefficients, instead of using recursion relations. Accuracy of the results is quite high for quantum numbers l 1 , and l 2 up to 100. Despite direct calculation, the CPU times are found comparable with those given in the related literature. 11 refs., 1 fig., 2 tabs

Confidence bands for inverse regression models

International Nuclear Information System (INIS)

Birke, Melanie; Bissantz, Nicolai; Holzmann, Hajo

2010-01-01

We construct uniform confidence bands for the regression function in inverse, homoscedastic regression models with convolution-type operators. Here, the convolution is between two non-periodic functions on the whole real line rather than between two periodic functions on a compact interval, since the former situation arguably arises more often in applications. First, following Bickel and Rosenblatt (1973 Ann. Stat. 1 1071–95) we construct asymptotic confidence bands which are based on strong approximations and on a limit theorem for the supremum of a stationary Gaussian process. Further, we propose bootstrap confidence bands based on the residual bootstrap and prove consistency of the bootstrap procedure. A simulation study shows that the bootstrap confidence bands perform reasonably well for moderate sample sizes. Finally, we apply our method to data from a gel electrophoresis experiment with genetically engineered neuronal receptor subunits incubated with rat brain extract

Nuclear power: restoring public confidence

International Nuclear Information System (INIS)

Arnold, L.

1986-01-01

The paper concerns a one day conference on nuclear power organised by the Centre for Science Studies and Science Policy, Lancaster, April 1986. Following the Chernobyl reactor accident, the conference concentrated on public confidence in nuclear power. Causes of lack of public confidence, public perceptions of risk, and the effect of Chernobyl in the United Kingdom, were all discussed. A Select Committee on the Environment examined the problems of radioactive waste disposal. (U.K.)

Validation to Portuguese of the Scale of Student Satisfaction and Self-Confidence in Learning.

Science.gov (United States)

Almeida, Rodrigo Guimarães dos Santos; Mazzo, Alessandra; Martins, José Carlos Amado; Baptista, Rui Carlos Negrão; Girão, Fernanda Berchelli; Mendes, Isabel Amélia Costa

2015-01-01

Translate and validate to Portuguese the Scale of Student Satisfaction and Self-Confidence in Learning. Methodological translation and validation study of a research tool. After following all steps of the translation process, for the validation process, the event III Workshop Brazil - Portugal: Care Delivery to Critical Patients was created, promoted by one Brazilian and another Portuguese teaching institution. 103 nurses participated. As to the validity and reliability of the scale, the correlation pattern between the variables, the sampling adequacy test (Kaiser-Meyer-Olkin) and the sphericity test (Bartlett) showed good results. In the exploratory factorial analysis (Varimax), item 9 behaved better in factor 1 (Satisfaction) than in factor 2 (Self-confidence in learning). The internal consistency (Cronbach's alpha) showed coefficients of 0.86 in factor 1 with six items and 0.77 for factor 2 with 07 items. In Portuguese this tool was called: Escala de Satisfação de Estudantes e Autoconfiança na Aprendizagem. The results found good psychometric properties and a good potential use. The sampling size and specificity are limitations of this study, but future studies will contribute to consolidate the validity of the scale and strengthen its potential use.

Coronal oblique imaging of the knee: Can it increase radiologists' confidence in diagnosing posterior root meniscal tears?

International Nuclear Information System (INIS)

Casagranda, B.U.; Leeman, J.; Costello, J.M.; Rafiee, B.; Harner, C.D.

2013-01-01

Aim: To investigate the utility of the coronal oblique sequence in the interrogation of posterior root meniscal lesions. Materials and methods: Following international review board approval, 62 consecutive knee arthroscopy cases were referred to the musculoskeletal (MSK) radiologists from the same orthopaedic surgeon for imaging/surgical correlation of the posterior meniscal roots. Of 62 cases, 45 lateral and 46 medial menisci met the inclusion criteria. Imaging evaluation was performed with standard magnetic resonance imaging (MRI) sequences, including a coronal oblique proton density sequence. Two blinded fellowship-trained MSK radiologists independently evaluated the menisci on standard sequences indicating whether a tear was identified and then specifying a confidence score using a scale of 1–3 on each study interpreted. Immediately thereafter, the coronal oblique sequence was evaluated using the same method. Statistics were performed on meniscal lesions involving the posterior horn/root junction or isolated root tears comparing confidence scores. Results: Reader A identified nine posterior horn/root junction tears and 14 isolated root tears. Following the addition of the coronal oblique sequence, confidence scores increased in three of 14 (21.4%) isolated root tears. All three final reads were concordant with arthroscopy. Reader B identified 10 posterior horn/root junction tears and 19 isolated root tears. The confidence score increased in six cases: five of 19 (26.3%) isolated root tears and one of 10 (10%) posterior horn/root junction tears. All six final reads were concordant with arthroscopy. Kappa coefficients indicated near perfect agreement. Conclusion: The coronal oblique sequence increased reader confidence in nearly 24% of the posterior root cases identified in this series

Organic labbeling systems and consumer confidence

OpenAIRE

Sønderskov, Kim Mannemar; Daugbjerg, Carsten

2009-01-01

A research analysis suggests that a state certification and labelling system creates confidence in organic labelling systems and consequently green consumerism. Danish consumers have higher levels of confidence in the labelling system than consumers in countries where the state plays a minor role in labelling and certification.

High-resolution Fourier transform measurements of air-induced broadening and shift coefficients in the 0002-0000 main isotopologue band of nitrous oxide

Science.gov (United States)

Werwein, Viktor; Li, Gang; Serdyukov, Anton; Brunzendorf, Jens; Werhahn, Olav; Ebert, Volker

2018-06-01

In the present study, we report highly accurate air-induced broadening and shift coefficients for the nitrous oxide (N2O) 0002-0000 band at 2.26 μm of the main isotopologue retrieved from high-resolution Fourier transform infrared (FTIR) measurements with metrologically determined pressure, temperature, absorption path length and chemical composition. Most of our retrieved air-broadening coefficients agree with previously generated datasets within the expanded (confidence interval of 95%) uncertainties. For the air-shift coefficients our results suggest a different rotational dependence compared to literature. The present study benefits from improved measurement conditions and a detailed metrological uncertainty description. Comparing to literature, the uncertainties of the previous broadening and shift coefficients are improved by a factor of up to 39 and up to 22, respectively.

Consumer confidence or the business cycle

DEFF Research Database (Denmark)

Møller, Stig Vinther; Nørholm, Henrik; Rangvid, Jesper

2014-01-01

Answer: The business cycle. We show that consumer confidence and the output gap both excess returns on stocks in many European countries: When the output gap is positive (the economy is doing well), expected returns are low, and when consumer confidence is high, expected returns are also low...

Reducing public communication apprehension by boosting self confidence on communication competence

Directory of Open Access Journals (Sweden)

Eva Rachmi

2012-07-01

medical doctor should be competent in communicating with others. Some students at the medical faculty Universitas Mulawarman tend to be silent at public communication training, and this is thought to be influenced by communication anxiety. This study aimed to analyze the possibility of self-confidence on communication competence and communication skills are risk factors of communication apprehension. Methods: This study was conducted on 55 students at the medical faculty Universitas Mulawarman.  Public communication apprehension was measured using the Personal Report of Communication Apprehension (PRCA-24. Confidence in communication competence was determined by the Self Perceived Communication Competence scale (SPCC.  Communication skills were based on the instructor’s score during the communication training program. Data were analyzed by linear regression to identify dominant factors using STATA 9.0. Results: The study showed a negative association between public communication apprehension and students’ self confidence in communication competence [coefficient regression (CR =-0.13; p=0.000; 95% confidence interval (CI=-0.20; -0.52]. However, it was not related to communication skills (p=0.936. Among twelve traits of self confidence on communication competence, students who had confidence to talk to a group of strangers had lower public communication apprehension (adjusted CR=-0.13; CI=-0.21; 0.05; p=0.002. Conclusions:  Increased confidence in their communication competence will reduce the degree of public communication apprehension by students. Therefore, the faculty should provide more opportunities for students to practice public communication, in particular, talking to a group of strangers more frequently. (Health Science Indones 2010; 1: 37 - 42

Communication confidence in persons with aphasia.

Science.gov (United States)

Babbitt, Edna M; Cherney, Leora R

2010-01-01

Communication confidence is a construct that has not been explored in the aphasia literature. Recently, national and international organizations have endorsed broader assessment methods that address quality of life and include participation, activity, and impairment domains as well as psychosocial areas. Individuals with aphasia encounter difficulties in all these areas on a daily basis in living with a communication disorder. Improvements are often reflected in narratives that are not typically included in standard assessments. This article illustrates how a new instrument measuring communication confidence might fit into a broad assessment framework and discusses the interaction of communication confidence, autonomy, and self-determination for individuals living with aphasia.

Coefficient estimates of negative powers and inverse coefficients for ...

Indian Academy of Sciences (India)

and the inequality is sharp for the inverse of the Koebe function k(z) = z/(1 − z)2. An alternative approach to the inverse coefficient problem for functions in the class S has been investigated by Schaeffer and Spencer [27] and FitzGerald [6]. Although, the inverse coefficient problem for the class S has been completely solved ...

Sex differences in confidence influence patterns of conformity.

Science.gov (United States)

Cross, Catharine P; Brown, Gillian R; Morgan, Thomas J H; Laland, Kevin N

2017-11-01

Lack of confidence in one's own ability can increase the likelihood of relying on social information. Sex differences in confidence have been extensively investigated in cognitive tasks, but implications for conformity have not been directly tested. Here, we tested the hypothesis that, in a task that shows sex differences in confidence, an indirect effect of sex on social information use will also be evident. Participants (N = 168) were administered a mental rotation (MR) task or a letter transformation (LT) task. After providing an answer, participants reported their confidence before seeing the responses of demonstrators and being allowed to change their initial answer. In the MR, but not the LT, task, women showed lower levels of confidence than men, and confidence mediated an indirect effect of sex on the likelihood of switching answers. These results provide novel, experimental evidence that confidence is a general explanatory mechanism underpinning susceptibility to social influences. Our results have implications for the interpretation of the wider literature on sex differences in conformity. © 2016 The British Psychological Society.

Comprehensive Plan for Public Confidence in Nuclear Regulator

International Nuclear Information System (INIS)

Choi, Kwang Sik; Choi, Young Sung; Kim, Ho ki

2008-01-01

Public confidence in nuclear regulator has been discussed internationally. Public trust or confidence is needed for achieving regulatory goal of assuring nuclear safety to the level that is acceptable by the public or providing public ease for nuclear safety. In Korea, public ease or public confidence has been suggested as major policy goal in the 'Nuclear regulatory policy direction' annually announced. This paper reviews theory of trust, its definitions and defines nuclear safety regulation, elements of public trust or public confidence developed based on the study conducted so far. Public ease model developed and 10 measures for ensuring public confidence are also presented and future study directions are suggested

Simultaneous confidence bands for the integrated hazard function

OpenAIRE

Dudek, Anna; Gocwin, Maciej; Leskow, Jacek

2006-01-01

The construction of the simultaneous confidence bands for the integrated hazard function is considered. The Nelson--Aalen estimator is used. The simultaneous confidence bands based on bootstrap methods are presented. Two methods of construction of such confidence bands are proposed. The weird bootstrap method is used for resampling. Simulations are made to compare the actual coverage probability of the bootstrap and the asymptotic simultaneous confidence bands. It is shown that the equal--tai...

Beyond hypercorrection: remembering corrective feedback for low-confidence errors.

Science.gov (United States)

Griffiths, Lauren; Higham, Philip A

2018-02-01

Correcting errors based on corrective feedback is essential to successful learning. Previous studies have found that corrections to high-confidence errors are better remembered than low-confidence errors (the hypercorrection effect). The aim of this study was to investigate whether corrections to low-confidence errors can also be successfully retained in some cases. Participants completed an initial multiple-choice test consisting of control, trick and easy general-knowledge questions, rated their confidence after answering each question, and then received immediate corrective feedback. After a short delay, they were given a cued-recall test consisting of the same questions. In two experiments, we found high-confidence errors to control questions were better corrected on the second test compared to low-confidence errors - the typical hypercorrection effect. However, low-confidence errors to trick questions were just as likely to be corrected as high-confidence errors. Most surprisingly, we found that memory for the feedback and original responses, not confidence or surprise, were significant predictors of error correction. We conclude that for some types of material, there is an effortful process of elaboration and problem solving prior to making low-confidence errors that facilitates memory of corrective feedback.

Converting Sabine absorption coefficients to random incidence absorption coefficients

DEFF Research Database (Denmark)

Jeong, Cheol-Ho

2013-01-01

are suggested: An optimization method for the surface impedances for locally reacting absorbers, the flow resistivity for extendedly reacting absorbers, and the flow resistance for fabrics. With four porous type absorbers, the conversion methods are validated. For absorbers backed by a rigid wall, the surface...... coefficients to random incidence absorption coefficients are proposed. The overestimations of the Sabine absorption coefficient are investigated theoretically based on Miki's model for porous absorbers backed by a rigid wall or an air cavity, resulting in conversion factors. Additionally, three optimizations...... impedance optimization produces the best results, while the flow resistivity optimization also yields reasonable results. The flow resistivity and flow resistance optimization for extendedly reacting absorbers are also found to be successful. However, the theoretical conversion factors based on Miki's model...

Maternal Confidence for Physiologic Childbirth: A Concept Analysis.

Science.gov (United States)

Neerland, Carrie E

2018-06-06

Confidence is a term often used in research literature and consumer media in relation to birth, but maternal confidence has not been clearly defined, especially as it relates to physiologic labor and birth. The aim of this concept analysis was to define maternal confidence in the context of physiologic labor and childbirth. Rodgers' evolutionary method was used to identify attributes, antecedents, and consequences of maternal confidence for physiologic birth. Databases searched included Ovid MEDLINE, CINAHL, PsycINFO, and Sociological Abstracts from the years 1995 to 2015. A total of 505 articles were retrieved, using the search terms pregnancy, obstetric care, prenatal care, and self-efficacy and the keyword confidence. Articles were identified for in-depth review and inclusion based on whether the term confidence was used or assessed in relationship to labor and/or birth. In addition, a hand search of the reference lists of the selected articles was performed. Twenty-four articles were reviewed in this concept analysis. We define maternal confidence for physiologic birth as a woman's belief that physiologic birth can be achieved, based on her view of birth as a normal process and her belief in her body's innate ability to birth, which is supported by social support, knowledge, and information founded on a trusted relationship with a maternity care provider in an environment where the woman feels safe. This concept analysis advances the concept of maternal confidence for physiologic birth and provides new insight into how women's confidence for physiologic birth might be enhanced during the prenatal period. Further investigation of confidence for physiologic birth across different cultures is needed to identify cultural differences in constructions of the concept. © 2018 by the American College of Nurse-Midwives.

Self-Confidence in the Hospitality Industry

Directory of Open Access Journals (Sweden)

Michael Oshins

2014-02-01

Full Text Available Few industries rely on self-confidence to the extent that the hospitality industry does because guests must feel welcome and that they are in capable hands. This article examines the results of hundreds of student interviews with industry professionals at all levels to determine where the majority of the hospitality industry gets their self-confidence.

ADAM SMITH: THE INVISIBLE HAND OR CONFIDENCE

Directory of Open Access Journals (Sweden)

Fernando Luis, Gache

2010-01-01

Full Text Available In 1776 Adam Smith raised the matter that an invisible hand was the one which moved the markets to obtain its efficiency. Despite in the present paper we are going to raise the hypothesis, that this invisible hand is in fact the confidence that each person feels when he is going to do business. That in addition it is unique, because it is different from the confidence of the others and that is a variable nonlinear that essentially is ligatured to respective personal histories. For that we are going to take as its bases the paper by Leopoldo Abadía (2009, with respect to the financial economy crisis that happened in 2007-2008, to evidence the form in which confidence operates. Therefore the contribution that we hope to do with this paper is to emphasize that, the level of confidence of the different actors, is the one which really moves the markets, (therefore the economy and that the crisis of the subprime mortgages is a confidence crisis at world-wide level.

Coefficient Alpha: A Reliability Coefficient for the 21st Century?

Science.gov (United States)

Yang, Yanyun; Green, Samuel B.

2011-01-01

Coefficient alpha is almost universally applied to assess reliability of scales in psychology. We argue that researchers should consider alternatives to coefficient alpha. Our preference is for structural equation modeling (SEM) estimates of reliability because they are informative and allow for an empirical evaluation of the assumptions…

Trust, confidence, and the 2008 global financial crisis.

Science.gov (United States)

Earle, Timothy C

2009-06-01

The 2008 global financial crisis has been compared to a "once-in-a-century credit tsunami," a disaster in which the loss of trust and confidence played key precipitating roles and the recovery from which will require the restoration of these crucial factors. Drawing on the analogy between the financial crisis and environmental and technological hazards, recent research on the role of trust and confidence in the latter is used to provide a perspective on the former. Whereas "trust" and "confidence" are used interchangeably and without explicit definition in most discussions of the financial crisis, this perspective uses the TCC model of cooperation to clearly distinguish between the two and to demonstrate how this distinction can lead to an improved understanding of the crisis. The roles of trust and confidence-both in precipitation and in possible recovery-are discussed for each of the three major sets of actors in the crisis, the regulators, the banks, and the public. The roles of trust and confidence in the larger context of risk management are also examined; trust being associated with political approaches, confidence with technical. Finally, the various stances that government can take with regard to trust-such as supportive or skeptical-are considered. Overall, it is argued that a clear understanding of trust and confidence and a close examination of the specific, concrete circumstances of a crisis-revealing when either trust or confidence is appropriate-can lead to useful insights for both recovery and prevention of future occurrences.

49 CFR 1103.23 - Confidences of a client.

Science.gov (United States)

2010-10-01

... 49 Transportation 8 2010-10-01 2010-10-01 false Confidences of a client. 1103.23 Section 1103.23... Responsibilities Toward A Client § 1103.23 Confidences of a client. (a) The practitioner's duty to preserve his client's confidence outlasts the practitioner's employment by the client, and this duty extends to the...

Confidence assessment. Site-descriptive modelling SDM-Site Laxemar

International Nuclear Information System (INIS)

2009-06-01

The objective of this report is to assess the confidence that can be placed in the Laxemar site descriptive model, based on the information available at the conclusion of the surface-based investigations (SDM-Site Laxemar). In this exploration, an overriding question is whether remaining uncertainties are significant for repository engineering design or long-term safety assessment and could successfully be further reduced by more surface-based investigations or more usefully by explorations underground made during construction of the repository. Procedures for this assessment have been progressively refined during the course of the site descriptive modelling, and applied to all previous versions of the Forsmark and Laxemar site descriptive models. They include assessment of whether all relevant data have been considered and understood, identification of the main uncertainties and their causes, possible alternative models and their handling, and consistency between disciplines. The assessment then forms the basis for an overall confidence statement. The confidence in the Laxemar site descriptive model, based on the data available at the conclusion of the surface based site investigations, has been assessed by exploring: - Confidence in the site characterization data base, - remaining issues and their handling, - handling of alternatives, - consistency between disciplines and - main reasons for confidence and lack of confidence in the model. Generally, the site investigation database is of high quality, as assured by the quality procedures applied. It is judged that the Laxemar site descriptive model has an overall high level of confidence. Because of the relatively robust geological model that describes the site, the overall confidence in the Laxemar Site Descriptive model is judged to be high, even though details of the spatial variability remain unknown. The overall reason for this confidence is the wide spatial distribution of the data and the consistency between

Confidence assessment. Site-descriptive modelling SDM-Site Laxemar

Energy Technology Data Exchange (ETDEWEB)

2008-12-15

The objective of this report is to assess the confidence that can be placed in the Laxemar site descriptive model, based on the information available at the conclusion of the surface-based investigations (SDM-Site Laxemar). In this exploration, an overriding question is whether remaining uncertainties are significant for repository engineering design or long-term safety assessment and could successfully be further reduced by more surface-based investigations or more usefully by explorations underground made during construction of the repository. Procedures for this assessment have been progressively refined during the course of the site descriptive modelling, and applied to all previous versions of the Forsmark and Laxemar site descriptive models. They include assessment of whether all relevant data have been considered and understood, identification of the main uncertainties and their causes, possible alternative models and their handling, and consistency between disciplines. The assessment then forms the basis for an overall confidence statement. The confidence in the Laxemar site descriptive model, based on the data available at the conclusion of the surface based site investigations, has been assessed by exploring: - Confidence in the site characterization data base, - remaining issues and their handling, - handling of alternatives, - consistency between disciplines and - main reasons for confidence and lack of confidence in the model. Generally, the site investigation database is of high quality, as assured by the quality procedures applied. It is judged that the Laxemar site descriptive model has an overall high level of confidence. Because of the relatively robust geological model that describes the site, the overall confidence in the Laxemar Site Descriptive model is judged to be high, even though details of the spatial variability remain unknown. The overall reason for this confidence is the wide spatial distribution of the data and the consistency between

Recurrence relations between transformation coefficients of hyperspherical harmonics and their application to Moshinsky coefficients

International Nuclear Information System (INIS)

Raynal, J.

1976-01-01

Closed formulae and recurrence relations for the transformation of a two-body harmonic oscillator wave function to the hyperspherical formalism are given. With them Moshinsky or Smirnov coefficients are obtained from the transformation coefficients of hyperspheric harmonics. For these coefficients the diagonalization method of Talman and Lande reduces to simple recurrence relations which can be used directly to compute them. New closed formulae for these coefficients are also derived: they are needed to compute the two simplest coefficients which determine the sign for the recurrence relation. (Auth.)

Validation to Portuguese of the Scale of Student Satisfaction and Self-Confidence in Learning

Directory of Open Access Journals (Sweden)

Rodrigo Guimarães dos Santos Almeida

2015-12-01

Full Text Available Objective: translate and validate to Portuguese the Scale of Student Satisfaction and Self-Confidence in Learning. Material and Methods: methodological translation and validation study of a research tool. After following all steps of the translation process, for the validation process, the event III Workshop Brazil - Portugal: Care Delivery to Critical Patients was created, promoted by one Brazilian and another Portuguese teaching institution. Results: 103 nurses participated. As to the validity and reliability of the scale, the correlation pattern between the variables, the sampling adequacy test (Kaiser-Meyer-Olkin and the sphericity test (Bartlett showed good results. In the exploratory factorial analysis (Varimax, item 9 behaved better in factor 1 (Satisfaction than in factor 2 (Self-confidence in learning. The internal consistency (Cronbach's alpha showed coefficients of 0.86 in factor 1 with six items and 0.77 for factor 2 with 07 items. Conclusion: in Portuguese this tool was called: Escala de Satisfação de Estudantes e Autoconfiança na Aprendizagem. The results found good psychometric properties and a good potential use. The sampling size and specificity are limitations of this study, but future studies will contribute to consolidate the validity of the scale and strengthen its potential use.

High Confidence Software and Systems Research Needs

Data.gov (United States)

Networking and Information Technology Research and Development, Executive Office of the President — This White Paper presents a survey of high confidence software and systems research needs. It has been prepared by the High Confidence Software and Systems...

Confidence in Alternative Dispute Resolution: Experience from Switzerland

Directory of Open Access Journals (Sweden)

Christof Schwenkel

2014-06-01

Full Text Available Alternative Dispute Resolution plays a crucial role in the justice system of Switzerland. With the unified Swiss Code of Civil Procedure, it is required that each litigation session shall be preceded by an attempt at conciliation before a conciliation authority. However, there has been little research on conciliation authorities and the public's perception of the authorities. This paper looks at public confidence in conciliation authorities and provides results of a survey conducted with more than 3,400 participants. This study found that public confidence in Swiss conciliation authorities is generally high, exceeds the ratings for confidence in cantonal governments and parliaments, but is lower than confidence in courts.Since the institutional models of the conciliation authorities (meaning the organization of the authorities and the selection of the conciliators differ widely between the 26 Swiss cantons, the influence of the institutional models on public confidence is analyzed. Contrary to assumptions based on New Institutional-ism approaches, this study reports that the institutional models do not impact public confidence. Also, the relationship between a participation in an election of justices of the peace or conciliators and public confidence in these authorities is found to be at most very limited (and negative. Similar to common findings on courts, the results show that general contacts with conciliation authorities decrease public confidence in these institutions whereas a positive experience with a conciliation authority leads to more confidence.The Study was completed as part of the research project 'Basic Research into Court Management in Switzerland', supported by the Swiss National Science Foundation (SNSF. Christof Schwenkel is a PhD student at the University of Lucerne and a research associate and project manager at Interface Policy Studies. A first version of this article was presented at the 2013 European Group for Public

Food skills confidence and household gatekeepers' dietary practices.

Science.gov (United States)

Burton, Melissa; Reid, Mike; Worsley, Anthony; Mavondo, Felix

2017-01-01

Household food gatekeepers have the potential to influence the food attitudes and behaviours of family members, as they are mainly responsible for food-related tasks in the home. The aim of this study was to determine the role of gatekeepers' confidence in food-related skills and nutrition knowledge on food practices in the home. An online survey was completed by 1059 Australian dietary gatekeepers selected from the Global Market Insite (GMI) research database. Participants responded to questions about food acquisition and preparation behaviours, the home eating environment, perceptions and attitudes towards food, and demographics. Two-step cluster analysis was used to identify groups based on confidence regarding food skills and nutrition knowledge. Chi-square tests and one-way ANOVAs were used to compare the groups on the dependent variables. Three groups were identified: low confidence, moderate confidence and high confidence. Gatekeepers in the highest confidence group were significantly more likely to report lower body mass index (BMI), and indicate higher importance of fresh food products, vegetable prominence in meals, product information use, meal planning, perceived behavioural control and overall diet satisfaction. Gatekeepers in the lowest confidence group were significantly more likely to indicate more perceived barriers to healthy eating, report more time constraints and more impulse purchasing practices, and higher convenience ingredient use. Other smaller associations were also found. Household food gatekeepers with high food skills confidence were more likely to engage in several healthy food practices, while those with low food skills confidence were more likely to engage in unhealthy food practices. Food education strategies aimed at building food-skills and nutrition knowledge will enable current and future gatekeepers to make healthier food decisions for themselves and for their families. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fragility estimation for seismically isolated nuclear structures by high confidence low probability of failure values and bi-linear regression

International Nuclear Information System (INIS)

Carausu, A.

1996-01-01

A method for the fragility estimation of seismically isolated nuclear power plant structure is proposed. The relationship between the ground motion intensity parameter (e.g. peak ground velocity or peak ground acceleration) and the response of isolated structures is expressed in terms of a bi-linear regression line, whose coefficients are estimated by the least-square method in terms of available data on seismic input and structural response. The notion of high confidence low probability of failure (HCLPF) value is also used for deriving compound fragility curves for coupled subsystems. (orig.)

A parameterization scheme for the x-ray linear attenuation coefficient and energy absorption coefficient.

Science.gov (United States)

Midgley, S M

2004-01-21

A novel parameterization of x-ray interaction cross-sections is developed, and employed to describe the x-ray linear attenuation coefficient and mass energy absorption coefficient for both elements and mixtures. The new parameterization scheme addresses the Z-dependence of elemental cross-sections (per electron) using a simple function of atomic number, Z. This obviates the need for a complicated mathematical formalism. Energy dependent coefficients describe the Z-direction curvature of the cross-sections. The composition dependent quantities are the electron density and statistical moments describing the elemental distribution. We show that it is possible to describe elemental cross-sections for the entire periodic table and at energies above the K-edge (from 6 keV to 125 MeV), with an accuracy of better than 2% using a parameterization containing not more than five coefficients. For the biologically important elements 1 coefficients. At higher energies, the parameterization uses fewer coefficients with only two coefficients needed at megavoltage energies.

Music educators : their artistry and self-confidence

NARCIS (Netherlands)

Lion-Slovak, Brigitte; Stöger, Christine; Smilde, Rineke; Malmberg, Isolde; de Vugt, Adri

2013-01-01

How does artistic identity influence the self-confidence of music educators? What is the interconnection between the artistic and the teacher identity? What is actually meant by artistic identity in music education? What is a fruitful environment for the development of artistic self-confidence of

Financial Literacy, Confidence and Financial Advice Seeking

NARCIS (Netherlands)

Kramer, Marc M.

2016-01-01

We find that people with higher confidence in their own financial literacy are less likely to seek financial advice, but no relation between objective measures of literacy and advice seeking. The negative association between confidence and advice seeking is more pronounced among wealthy households.

Confidence building in implementation of geological disposal

International Nuclear Information System (INIS)

Umeki, Hiroyuki

2004-01-01

Long-term safety of the disposal system should be demonstrated to the satisfaction of the stakeholders. Convincing arguments are therefore required that instil in the stakeholders confidence in the safety of a particular concept for the siting and design of a geological disposal, given the uncertainties that inevitably exist in its a priori description and in its evolution. The step-wise approach associated with making safety case at each stage is a key to building confidence in the repository development programme. This paper discusses aspects and issues on confidence building in the implementation of HLW disposal in Japan. (author)

The correlation between apparent diffusion coefficient and tumor cellularity in patients: a meta-analysis.

Science.gov (United States)

Chen, Lihua; Liu, Min; Bao, Jing; Xia, Yunbao; Zhang, Jiuquan; Zhang, Lin; Huang, Xuequan; Wang, Jian

2013-01-01

To perform a meta-analysis exploring the correlation between the apparent diffusion coefficient (ADC) and tumor cellularity in patients. We searched medical and scientific literature databases for studies discussing the correlation between the ADC and tumor cellularity in patients. Only studies that were published in English or Chinese prior to November 2012 were considered for inclusion. Summary correlation coefficient (r) values were extracted from each study, and 95% confidence intervals (CIs) were calculated. Sensitivity and subgroup analyses were performed to investigate potential heterogeneity. Of 189 studies, 28 were included in the meta-analysis, comprising 729 patients. The pooled r for all studies was -0.57 (95% CI: -0.62, -0.52), indicating notable heterogeneity (Pcorrelation between the ADC and cellularity for brain tumors. There was no notable evidence of publication bias. There is a strong negative correlation between the ADC and tumor cellularity in patients, particularly in the brain. However, larger, prospective studies are warranted to validate these findings in other cancer types.

Frontline nurse managers' confidence and self-efficacy.

Science.gov (United States)

Van Dyk, Jennifer; Siedlecki, Sandra L; Fitzpatrick, Joyce J

2016-05-01

This study was focused on determining relationships between confidence levels and self-efficacy among nurse managers. Frontline nurse managers have a pivotal role in delivering high-quality patient care while managing the associated costs and resources. The competency and skill of nurse managers affect every aspect of patient care and staff well-being as nurse managers are largely responsible for creating work environments in which clinical nurses are able to provide high-quality, patient-centred, holistic care. A descriptive, correlational survey design was used; 85 nurse managers participated. Years in a formal leadership role and confidence scores were found to be significant predictors of self-efficacy scores. Experience as a nurse manager is an important component of confidence and self-efficacy. There is a need to develop educational programmes for nurse managers to enhance their self-confidence and self-efficacy, and to maintain experienced nurse managers in the role. © 2016 John Wiley & Sons Ltd.

Weighting Mean and Variability during Confidence Judgments

Science.gov (United States)

de Gardelle, Vincent; Mamassian, Pascal

2015-01-01

Humans can not only perform some visual tasks with great precision, they can also judge how good they are in these tasks. However, it remains unclear how observers produce such metacognitive evaluations, and how these evaluations might be dissociated from the performance in the visual task. Here, we hypothesized that some stimulus variables could affect confidence judgments above and beyond their impact on performance. In a motion categorization task on moving dots, we manipulated the mean and the variance of the motion directions, to obtain a low-mean low-variance condition and a high-mean high-variance condition with matched performances. Critically, in terms of confidence, observers were not indifferent between these two conditions. Observers exhibited marked preferences, which were heterogeneous across individuals, but stable within each observer when assessed one week later. Thus, confidence and performance are dissociable and observers’ confidence judgments put different weights on the stimulus variables that limit performance. PMID:25793275

Confidence and self-attribution bias in an artificial stock market

Science.gov (United States)

Bertella, Mario A.; Pires, Felipe R.; Rego, Henio H. A.; Vodenska, Irena; Stanley, H. Eugene

2017-01-01

Using an agent-based model we examine the dynamics of stock price fluctuations and their rates of return in an artificial financial market composed of fundamentalist and chartist agents with and without confidence. We find that chartist agents who are confident generate higher price and rate of return volatilities than those who are not. We also find that kurtosis and skewness are lower in our simulation study of agents who are not confident. We show that the stock price and confidence index—both generated by our model—are cointegrated and that stock price affects confidence index but confidence index does not affect stock price. We next compare the results of our model with the S&P 500 index and its respective stock market confidence index using cointegration and Granger tests. As in our model, we find that stock prices drive their respective confidence indices, but that the opposite relationship, i.e., the assumption that confidence indices drive stock prices, is not significant. PMID:28231255

Weyl q-coefficients for uq(3) and Racah q -coefficients for suq(2)

International Nuclear Information System (INIS)

Asherova, R.M.; Smirnov, Yu.F.; Tolstoy, V.N.

1996-01-01

With the aid of the projection-operator technique, the general analytic expression for the elements of the matrix that relates the U and T bases of an arbitrary finite-dimensional irreducible representation of the uq(3) quantum algebra (Weyl q-coefficients) is obtained for the case where the deformation parameter q is not equal to a square root of unity. The procedure for resummation of q-factorial expressions is used to prove that, modulo phase factors, these Weyl q-coefficients coincide with Racah q-coefficients for the suq(2) quantum algebra. It is also shown that, on the basis of one general formula, the q-analogs of all known general analytic expressions for the 6j symbols (and Racah coefficients) of the Lie algebras of the angular momentum can be obtained by using this resummation procedure. The symmetry properties of these q coefficients are discussed. The result is formulated in the following way: the general formulas for the q-6j symbols (Racah q-coefficients) of the suq(2) quantum algebra are obtained from the general formulas for the conventional 6j symbols (Racah coefficients) of the su(2) Lie algebra by replacing directly all factorials with q-factorials, the symmetry properties of the q-6j symbols being completely coincident with the symmetry properties of the conventional 6j symbols

Improved realism of confidence for an episodic memory event

Directory of Open Access Journals (Sweden)

Sandra Buratti

2012-09-01

Full Text Available We asked whether people can make their confidence judgments more realistic (accurate by adjusting them, with the aim of improving the relationship between the level of confidence and the correctness of the answer. This adjustment can be considered to include a so-called second-order metacognitive judgment. The participants first gave confidence judgments about their answers to questions about a video clip they had just watched. Next, they attempted to increase their accuracy by identifying confidence judgments in need of adjustment and then modifying them. The participants managed to increase their metacognitive realism, thus decreasing their absolute bias and improving their calibration, although the effects were small. We also examined the relationship between confidence judgments that were adjusted and the retrieval fluency and the phenomenological memory quality participants experienced when first answering the questions; this quality was one of either Remember (associated with concrete, vivid details or Know (associated with a feeling of familiarity. Confidence judgments associated with low retrieval fluency and the memory quality of knowing were modified more often. In brief, our results provide evidence that people can improve the realism of their confidence judgments, mainly by decreasing their confidence for incorrect answers. Thus, this study supports the conclusion that people can perform successful second-order metacognitive judgments.

Building Public Confidence in Nuclear Activities

International Nuclear Information System (INIS)

Isaacs, T

2002-01-01

Achieving public acceptance has become a central issue in discussions regarding the future of nuclear power and associated nuclear activities. Effective public communication and public participation are often put forward as the key building blocks in garnering public acceptance. A recent international workshop in Finland provided insights into other features that might also be important to building and sustaining public confidence in nuclear activities. The workshop was held in Finland in close cooperation with Finnish stakeholders. This was most appropriate because of the recent successes in achieving positive decisions at the municipal, governmental, and Parliamentary levels, allowing the Finnish high-level radioactive waste repository program to proceed, including the identification and approval of a proposed candidate repository site. Much of the workshop discussion appropriately focused on the roles of public participation and public communications in building public confidence. It was clear that well constructed and implemented programs of public involvement and communication and a sense of fairness were essential in building the extent of public confidence needed to allow the repository program in Finland to proceed. It was also clear that there were a number of other elements beyond public involvement that contributed substantially to the success in Finland to date. And, in fact, it appeared that these other factors were also necessary to achieving the Finnish public acceptance. In other words, successful public participation and communication were necessary but not sufficient. What else was important? Culture, politics, and history vary from country to country, providing differing contexts for establishing and maintaining public confidence. What works in one country will not necessarily be effective in another. Nonetheless, there appear to be certain elements that might be common to programs that are successful in sustaining public confidence and some of

Building Public Confidence in Nuclear Activities

International Nuclear Information System (INIS)

Isaacs, T

2002-01-01

Achieving public acceptance has become a central issue in discussions regarding the future of nuclear power and associated nuclear activities. Effective public communication and public participation are often put forward as the key building blocks in garnering public acceptance. A recent international workshop in Finland provided insights into other features that might also be important to building and sustaining public confidence in nuclear activities. The workshop was held in Finland in close cooperation with Finnish stakeholders. This was most appropriate because of the recent successes in achieving positive decisions at the municipal, governmental, and Parliamentary levels, allowing the Finnish high-level radioactive waste repository program to proceed, including the identification and approval of a proposed candidate repository site Much of the workshop discussion appropriately focused on the roles of public participation and public communications in building public confidence. It was clear that well constructed and implemented programs of public involvement and communication and a sense of fairness were essential in building the extent of public confidence needed to allow the repository program in Finland to proceed. It was also clear that there were a number of other elements beyond public involvement that contributed substantially to the success in Finland to date. And, in fact, it appeared that these other factors were also necessary to achieving the Finnish public acceptance. In other words, successful public participation and communication were necessary but not sufficient. What else was important? Culture, politics, and history vary from country to country, providing differing contexts for establishing and maintaining public confidence. What works in one country will not necessarily be effective in another. Nonetheless, there appear to be certain elements that might be common to programs that are successful in sustaining public confidence, and some of

The Truth About Ballistic Coefficients

OpenAIRE

Courtney, Michael; Courtney, Amy

2007-01-01

The ballistic coefficient of a bullet describes how it slows in flight due to air resistance. This article presents experimental determinations of ballistic coefficients showing that the majority of bullets tested have their previously published ballistic coefficients exaggerated from 5-25% by the bullet manufacturers. These exaggerated ballistic coefficients lead to inaccurate predictions of long range bullet drop, retained energy and wind drift.

Interpretation of Confidence Interval Facing the Conflict

Science.gov (United States)

Andrade, Luisa; Fernández, Felipe

2016-01-01

As literature has reported, it is usual that university students in statistics courses, and even statistics teachers, interpret the confidence level associated with a confidence interval as the probability that the parameter value will be between the lower and upper interval limits. To confront this misconception, class activities have been…

Development of database on the distribution coefficient. 1. Collection of the distribution coefficient data

Energy Technology Data Exchange (ETDEWEB)

Takebe, Shinichi; Abe, Masayoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2001-03-01

The distribution coefficient is very important parameter for environmental impact assessment on the disposal of radioactive waste arising from research institutes. The literature survey in the country was mainly carried out for the purpose of selecting the reasonable distribution coefficient value on the utilization of this value in the safety evaluation. This report was arranged much informations on the distribution coefficient for inputting to the database for each literature, and was summarized as a literature information data on the distribution coefficient. (author)

Is consumer confidence an indicator of JSE performance?

OpenAIRE

Kamini Solanki; Yudhvir Seetharam

2014-01-01

While most studies examine the impact of business confidence on market performance, we instead focus on the consumer because consumer spending habits are a natural extension of trading activity on the equity market. This particular study examines investor sentiment as measured by the Consumer Confidence Index in South Africa and its effect on the Johannesburg Stock Exchange (JSE). We employ Granger causality tests to investigate the relationship across time between the Consumer Confidence Ind...

Confidence Interval Approximation For Treatment Variance In ...

African Journals Online (AJOL)

In a random effects model with a single factor, variation is partitioned into two as residual error variance and treatment variance. While a confidence interval can be imposed on the residual error variance, it is not possible to construct an exact confidence interval for the treatment variance. This is because the treatment ...

Self-confidence of anglers in identification of freshwater sport fish

Science.gov (United States)

Chizinski, C.J.; Martin, D. R.; Pope, Kevin L.

2014-01-01

Although several studies have focused on how well anglers identify species using replicas and pictures, there has been no study assessing the confidence that can be placed in angler's ability to identify recreationally important fish. Understanding factors associated with low self-confidence will be useful in tailoring education programmes to improve self-confidence in identifying common species. The purposes of this assessment were to quantify the confidence of recreational anglers to identify 13 commonly encountered warm water fish species and to relate self-confidence to species availability and angler experience. Significant variation was observed in anglers self-confidence among species and levels of self-declared skill, with greater confidence associated with greater skill and with greater exposure. This study of angler self-confidence strongly highlights the need for educational programmes that target lower skilled anglers and the importance of teaching all anglers about less common species, regardless of skill level.

Validation to Portuguese of the Scale of Student Satisfaction and Self-Confidence in Learning1

Science.gov (United States)

Almeida, Rodrigo Guimarães dos Santos; Mazzo, Alessandra; Martins, José Carlos Amado; Baptista, Rui Carlos Negrão; Girão, Fernanda Berchelli; Mendes, Isabel Amélia Costa

2015-01-01

Objective: translate and validate to Portuguese the Scale of Student Satisfaction and Self-Confidence in Learning. Material and Methods: methodological translation and validation study of a research tool. After following all steps of the translation process, for the validation process, the event III Workshop Brazil - Portugal: Care Delivery to Critical Patients was created, promoted by one Brazilian and another Portuguese teaching institution. Results: 103 nurses participated. As to the validity and reliability of the scale, the correlation pattern between the variables, the sampling adequacy test (Kaiser-Meyer-Olkin) and the sphericity test (Bartlett) showed good results. In the exploratory factorial analysis (Varimax), item 9 behaved better in factor 1 (Satisfaction) than in factor 2 (Self-confidence in learning). The internal consistency (Cronbach's alpha) showed coefficients of 0.86 in factor 1 with six items and 0.77 for factor 2 with 07 items. Conclusion: in Portuguese this tool was called: Escala de Satisfação de Estudantes e Autoconfiança na Aprendizagem. The results found good psychometric properties and a good potential use. The sampling size and specificity are limitations of this study, but future studies will contribute to consolidate the validity of the scale and strengthen its potential use. PMID:26625990

Effects of postidentification feedback on eyewitness identification and nonidentification confidence.

Science.gov (United States)

Semmler, Carolyn; Brewer, Neil; Wells, Gary L

2004-04-01

Two experiments investigated new dimensions of the effect of confirming feedback on eyewitness identification confidence using target-absent and target-present lineups and (previously unused) unbiased witness instructions (i.e., "offender not present" option highlighted). In Experiment 1, participants viewed a crime video and were later asked to try to identify the thief from an 8-person target-absent photo array. Feedback inflated witness confidence for both mistaken identifications and correct lineup rejections. With target-present lineups in Experiment 2, feedback inflated confidence for correct and mistaken identifications and lineup rejections. Although feedback had no influence on the confidence-accuracy correlation, it produced clear overconfidence. Confidence inflation varied with the confidence measure reference point (i.e., retrospective vs. current confidence) and identification response latency.

Confidence Intervals from Normalized Data: A correction to Cousineau (2005

Directory of Open Access Journals (Sweden)

Richard D. Morey

2008-09-01

Full Text Available Presenting confidence intervals around means is a common method of expressing uncertainty in data. Loftus and Masson (1994 describe confidence intervals for means in within-subjects designs. These confidence intervals are based on the ANOVA mean squared error. Cousineau (2005 presents an alternative to the Loftus and Masson method, but his method produces confidence intervals that are smaller than those of Loftus and Masson. I show why this is the case and offer a simple correction that makes the expected size of Cousineau confidence intervals the same as that of Loftus and Masson confidence intervals.

Doubly Bayesian Analysis of Confidence in Perceptual Decision-Making.

Science.gov (United States)

Aitchison, Laurence; Bang, Dan; Bahrami, Bahador; Latham, Peter E

2015-10-01

Humans stand out from other animals in that they are able to explicitly report on the reliability of their internal operations. This ability, which is known as metacognition, is typically studied by asking people to report their confidence in the correctness of some decision. However, the computations underlying confidence reports remain unclear. In this paper, we present a fully Bayesian method for directly comparing models of confidence. Using a visual two-interval forced-choice task, we tested whether confidence reports reflect heuristic computations (e.g. the magnitude of sensory data) or Bayes optimal ones (i.e. how likely a decision is to be correct given the sensory data). In a standard design in which subjects were first asked to make a decision, and only then gave their confidence, subjects were mostly Bayes optimal. In contrast, in a less-commonly used design in which subjects indicated their confidence and decision simultaneously, they were roughly equally likely to use the Bayes optimal strategy or to use a heuristic but suboptimal strategy. Our results suggest that, while people's confidence reports can reflect Bayes optimal computations, even a small unusual twist or additional element of complexity can prevent optimality.

Registered nurse leadership style and confidence in delegation.

Science.gov (United States)

Saccomano, Scott J; Pinto-Zipp, Genevieve

2011-05-01

  Leadership and confidence in delegation are two important explanatory constructs of nursing practice. The relationship between these constructs, however, is not clearly understood. To be successful in their roles as leaders, regardless of their experience, registered nurses (RNs) need to understand how to best delegate. The present study explored and described the relationship between RN leadership styles, demographic variables and confidence in delegation in a community teaching hospital. Utilizing a cross-sectional survey design, RNs employed in one acute care hospital completed questionnaires that measured leadership style [Path-Goal Leadership Questionnaire (PGLQ)] and confidence in delegating patient care tasks [Confidence and Intent to Delegate Scale (CIDS)]. Contrary to expectations, the data did not confirm a relationship between confidence in delegating tasks to unlicensed assistive personnel (UAPs) and leadership style. Nurses who were diploma or associate degree prepared were initially less confident in delegating tasks to UAPs as compared with RNs holding a bachelor's degree or higher. Further, after 5 years of clinical nursing experience, nurses with less educational experience reported more confidence in delegating tasks as compared with RNs with more educational experience. The lack of a relationship between leadership style and confidence in delegating patient care tasks were discussed in terms of the PGLQ classification criteria and hospital unit differences. As suggested by the significant two-way interaction between educational preparation and clinical nursing experience, changes in the nurse's confidence in delegating patient care tasks to UAPs was a dynamic changing variable that resulted from the interplay between amount of educational preparation and years of clinical nursing experience in this population of nurses. Clearly, generalizability of these findings to nurses outside the US is questionable, thus nurse managers must be familiar

Detecting Disease in Radiographs with Intuitive Confidence

Directory of Open Access Journals (Sweden)

Stefan Jaeger

2015-01-01

Full Text Available This paper argues in favor of a specific type of confidence for use in computer-aided diagnosis and disease classification, namely, sine/cosine values of angles represented by points on the unit circle. The paper shows how this confidence is motivated by Chinese medicine and how sine/cosine values are directly related with the two forces Yin and Yang. The angle for which sine and cosine are equal (45° represents the state of equilibrium between Yin and Yang, which is a state of nonduality that indicates neither normality nor abnormality in terms of disease classification. The paper claims that the proposed confidence is intuitive and can be readily understood by physicians. The paper underpins this thesis with theoretical results in neural signal processing, stating that a sine/cosine relationship between the actual input signal and the perceived (learned input is key to neural learning processes. As a practical example, the paper shows how to use the proposed confidence values to highlight manifestations of tuberculosis in frontal chest X-rays.

High confidence in falsely recognizing prototypical faces.

Science.gov (United States)

Sampaio, Cristina; Reinke, Victoria; Mathews, Jeffrey; Swart, Alexandra; Wallinger, Stephen

2018-06-01

We applied a metacognitive approach to investigate confidence in recognition of prototypical faces. Participants were presented with sets of faces constructed digitally as deviations from prototype/base faces. Participants were then tested with a simple recognition task (Experiment 1) or a multiple-choice task (Experiment 2) for old and new items plus new prototypes, and they showed a high rate of confident false alarms to the prototypes. Confidence and accuracy relationship in this face recognition paradigm was found to be positive for standard items but negative for the prototypes; thus, it was contingent on the nature of the items used. The data have implications for lineups that employ match-to-suspect strategies.

Confidence mediates the sex difference in mental rotation performance.

Science.gov (United States)

Estes, Zachary; Felker, Sydney

2012-06-01

On tasks that require the mental rotation of 3-dimensional figures, males typically exhibit higher accuracy than females. Using the most common measure of mental rotation (i.e., the Mental Rotations Test), we investigated whether individual variability in confidence mediates this sex difference in mental rotation performance. In each of four experiments, the sex difference was reliably elicited and eliminated by controlling or manipulating participants' confidence. Specifically, confidence predicted performance within and between sexes (Experiment 1), rendering confidence irrelevant to the task reliably eliminated the sex difference in performance (Experiments 2 and 3), and manipulating confidence significantly affected performance (Experiment 4). Thus, confidence mediates the sex difference in mental rotation performance and hence the sex difference appears to be a difference of performance rather than ability. Results are discussed in relation to other potential mediators and mechanisms, such as gender roles, sex stereotypes, spatial experience, rotation strategies, working memory, and spatial attention.

Extending the Constant Coefficient Solution Technique to Variable Coefficient Ordinary Differential Equations

Science.gov (United States)

Mohammed, Ahmed; Zeleke, Aklilu

2015-01-01

We introduce a class of second-order ordinary differential equations (ODEs) with variable coefficients whose closed-form solutions can be obtained by the same method used to solve ODEs with constant coefficients. General solutions for the homogeneous case are discussed.

Aging and Confidence Judgments in Item Recognition

Science.gov (United States)

Voskuilen, Chelsea; Ratcliff, Roger; McKoon, Gail

2018-01-01

We examined the effects of aging on performance in an item-recognition experiment with confidence judgments. A model for confidence judgments and response time (RTs; Ratcliff & Starns, 2013) was used to fit a large amount of data from a new sample of older adults and a previously reported sample of younger adults. This model of confidence…

Maximum-confidence discrimination among symmetric qudit states

International Nuclear Information System (INIS)

Jimenez, O.; Solis-Prosser, M. A.; Delgado, A.; Neves, L.

2011-01-01

We study the maximum-confidence (MC) measurement strategy for discriminating among nonorthogonal symmetric qudit states. Restricting to linearly dependent and equally likely pure states, we find the optimal positive operator valued measure (POVM) that maximizes our confidence in identifying each state in the set and minimizes the probability of obtaining inconclusive results. The physical realization of this POVM is completely determined and it is shown that after an inconclusive outcome, the input states may be mapped into a new set of equiprobable symmetric states, restricted, however, to a subspace of the original qudit Hilbert space. By applying the MC measurement again onto this new set, we can still gain some information about the input states, although with less confidence than before. This leads us to introduce the concept of sequential maximum-confidence (SMC) measurements, where the optimized MC strategy is iterated in as many stages as allowed by the input set, until no further information can be extracted from an inconclusive result. Within each stage of this measurement our confidence in identifying the input states is the highest possible, although it decreases from one stage to the next. In addition, the more stages we accomplish within the maximum allowed, the higher will be the probability of correct identification. We will discuss an explicit example of the optimal SMC measurement applied in the discrimination among four symmetric qutrit states and propose an optical network to implement it.

Understanding public confidence in government to prevent terrorist attacks.

Energy Technology Data Exchange (ETDEWEB)

Baldwin, T. E.; Ramaprasad, A,; Samsa, M. E.; Decision and Information Sciences; Univ. of Illinois at Chicago

2008-04-02

A primary goal of terrorism is to instill a sense of fear and vulnerability in a population and to erode its confidence in government and law enforcement agencies to protect citizens against future attacks. In recognition of its importance, the Department of Homeland Security includes public confidence as one of the principal metrics used to assess the consequences of terrorist attacks. Hence, a detailed understanding of the variations in public confidence among individuals, terrorist event types, and as a function of time is critical to developing this metric. In this exploratory study, a questionnaire was designed, tested, and administered to small groups of individuals to measure public confidence in the ability of federal, state, and local governments and their public safety agencies to prevent acts of terrorism. Data was collected from three groups before and after they watched mock television news broadcasts portraying a smallpox attack, a series of suicide bomber attacks, a refinery explosion attack, and cyber intrusions on financial institutions, resulting in identity theft. Our findings are: (a) although the aggregate confidence level is low, there are optimists and pessimists; (b) the subjects are discriminating in interpreting the nature of a terrorist attack, the time horizon, and its impact; (c) confidence recovery after a terrorist event has an incubation period; and (d) the patterns of recovery of confidence of the optimists and the pessimists are different. These findings can affect the strategy and policies to manage public confidence after a terrorist event.

Functional Dissociation of Confident and Not-Confident Errors in the Spatial Delayed Response Task Demonstrates Impairments in Working Memory Encoding and Maintenance in Schizophrenia

Directory of Open Access Journals (Sweden)

Jutta S. Mayer

2018-05-01

Full Text Available Even though extensively investigated, the nature of working memory (WM deficits in patients with schizophrenia (PSZ is not yet fully understood. In particular, the contribution of different WM sub-processes to the severe WM deficit observed in PSZ is a matter of debate. So far, most research has focused on impaired WM maintenance. By analyzing different types of errors in a spatial delayed response task (DRT, we have recently demonstrated that incorrect yet confident responses (which we labeled as false memory errors rather than incorrect/not-confident responses reflect failures of WM encoding, which was also impaired in PSZ. In the present study, we provide further evidence for a functional dissociation between confident and not-confident errors by manipulating the demands on WM maintenance, i.e., the length over which information has to be maintained in WM. Furthermore, we investigate whether these functionally distinguishable WM processes are impaired in PSZ. Twenty-four PSZ and 24 demographically matched healthy controls (HC performed a spatial DRT in which the length of the delay period was varied between 1, 2, 4, and 6 s. In each trial, participants also rated their level of response confidence. Across both groups, longer delays led to increased rates of incorrect/not-confident responses, while incorrect/confident responses were not affected by delay length. This functional dissociation provides additional support for our proposal that false memory errors (i.e., confident errors reflect problems at the level of WM encoding, while not-confident errors reflect failures of WM maintenance. Schizophrenic patients showed increased numbers of both confident and not-confident errors, suggesting that both sub-processes of WM—encoding and maintenance—are impaired in schizophrenia. Combined with the delay length-dependent functional dissociation, we propose that these impairments in schizophrenic patients are functionally distinguishable.

Effects of confidence and anxiety on flow state in competition.

Science.gov (United States)

Koehn, Stefan

2013-01-01

Confidence and anxiety are important variables that underlie the experience of flow in sport. Specifically, research has indicated that confidence displays a positive relationship and anxiety a negative relationship with flow. The aim of this study was to assess potential direct and indirect effects of confidence and anxiety dimensions on flow state in tennis competition. A sample of 59 junior tennis players completed measures of Competitive State Anxiety Inventory-2d and Flow State Scale-2. Following predictive analysis, results showed significant positive correlations between confidence (intensity and direction) and anxiety symptoms (only directional perceptions) with flow state. Standard multiple regression analysis indicated confidence as the only significant predictor of flow. The results confirmed a protective function of confidence against debilitating anxiety interpretations, but there were no significant interaction effects between confidence and anxiety on flow state.

Preservice teachers' perceived confidence in teaching school violence prevention.

Science.gov (United States)

Kandakai, Tina L; King, Keith A

2002-01-01

To examine preservice teachers' perceived confidence in teaching violence prevention and the potential effect of violence-prevention training on preservice teachers' confidence in teaching violence prevention. Six Ohio universities participated in the study. More than 800 undergraduate and graduate students completed surveys. Violence-prevention training, area of certification, and location of student- teaching placement significantly influenced preservice teachers' perceived confidence in teaching violence prevention. Violence-prevention training positively influences preservice teachers' confidence in teaching violence prevention. The results suggest that such training should be considered as a requirement for teacher preparation programs.

On the Kendall Correlation Coefficient

OpenAIRE

Stepanov, Alexei

2015-01-01

In the present paper, we first discuss the Kendall rank correlation coefficient. In continuous case, we define the Kendall rank correlation coefficient in terms of the concomitants of order statistics, find the expected value of the Kendall rank correlation coefficient and show that the later is free of n. We also prove that in continuous case the Kendall correlation coefficient converges in probability to its expected value. We then propose to consider the expected value of the Kendall rank ...

Self Confidence Spillovers and Motivated Beliefs

DEFF Research Database (Denmark)

Banerjee, Ritwik; Gupta, Nabanita Datta; Villeval, Marie Claire

that success when competing in a task increases the performers’ self-confidence and competitiveness in the subsequent task. We also find that such spillovers affect the self-confidence of low-status individuals more than that of high-status individuals. Receiving good news under Affirmative Action, however......Is success in a task used strategically by individuals to motivate their beliefs prior to taking action in a subsequent, unrelated, task? Also, is the distortion of beliefs reinforced for individuals who have lower status in society? Conducting an artefactual field experiment in India, we show...

Correlation coefficients in neutron β-decay

International Nuclear Information System (INIS)

Byrne, J.

1978-01-01

The various angular and polarisation coefficients in neutron decay are the principal sources of information on the β-interaction. Measurements of the electron-neutrino angular correlation coefficient (a), the neutron-spin-electron-momentum correlation coefficient (A), the neutron-spin-neutrino-momentum correlation coefficient (B), and the triple correlation coefficient D and time-reversal invariance are reviewed and the results discussed. (U.K.)

Alternative confidence measure for local matching stereo algorithms

CSIR Research Space (South Africa)

Ndhlovu, T

2009-11-01

Full Text Available The authors present a confidence measure applied to individual disparity estimates in local matching stereo correspondence algorithms. It aims at identifying textureless areas, where most local matching algorithms fail. The confidence measure works...

Coping skills: role of trait sport confidence and trait anxiety.

Science.gov (United States)

Cresswell, Scott; Hodge, Ken

2004-04-01

The current research assesses relationships among coping skills, trait sport confidence, and trait anxiety. Two samples (n=47 and n=77) of international competitors from surf life saving (M=23.7 yr.) and touch rugby (M=26.2 yr.) completed the Athletic Coping Skills Inventory, Trait Sport Confidence Inventory, and Sport Anxiety Scale. Analysis yielded significant correlations amongst trait anxiety, sport confidence, and coping. Specifically confidence scores were positively associated with coping with adversity scores and anxiety scores were negatively associated. These findings support the inclusion of the personality characteristics of confidence and anxiety within the coping model presented by Hardy, Jones, and Gould, Researchers should be aware that confidence and anxiety may influence the coping processes of athletes.

Reclaim your creative confidence.

Science.gov (United States)

Kelley, Tom; Kelley, David

2012-12-01

Most people are born creative. But over time, a lot of us learn to stifle those impulses. We become warier of judgment, more cautious more analytical. The world seems to divide into "creatives" and "noncreatives," and too many people resign themselves to the latter category. And yet we know that creativity is essential to success in any discipline or industry. The good news, according to authors Tom Kelley and David Kelley of IDEO, is that we all can rediscover our creative confidence. The trick is to overcome the four big fears that hold most of us back: fear of the messy unknown, fear of judgment, fear of the first step, and fear of losing control. The authors use an approach based on the work of psychologist Albert Bandura in helping patients get over their snake phobias: You break challenges down into small steps and then build confidence by succeeding on one after another. Creativity is something you practice, say the authors, not just a talent you are born with.

Factors affecting midwives' confidence in intrapartum care: a phenomenological study.

Science.gov (United States)

Bedwell, Carol; McGowan, Linda; Lavender, Tina

2015-01-01

midwives are frequently the lead providers of care for women throughout labour and birth. In order to perform their role effectively and provide women with the choices they require midwives need to be confident in their practice. This study explores factors which may affect midwives' confidence in their practice. hermeneutic phenomenology formed the theoretical basis for the study. Prospective longitudinal data collection was completed using diaries and semi-structured interviews. Twelve midwives providing intrapartum care in a variety of settings were recruited to ensure a variety of experiences in different contexts were captured. the principal factor affecting workplace confidence, both positively and negatively, was the influence of colleagues. Perceived autonomy and a sense of familiarity could also enhance confidence. However, conflict in the workplace was a critical factor in reducing midwives' confidence. Confidence was an important, but fragile, phenomenon to midwives and they used a variety of coping strategies, emotional intelligence and presentation management to maintain it. this is the first study to highlight both the factors influencing midwives' workplace confidence and the strategies midwives employed to maintain their confidence. Confidence is important in maintaining well-being and workplace culture may play a role in explaining the current low morale within the midwifery workforce. This may have implications for women's choices and care. Support, effective leadership and education may help midwives develop and sustain a positive sense of confidence. Copyright © 2014 Elsevier Ltd. All rights reserved.

nigerian students' self-confidence in responding to statements

African Journals Online (AJOL)

Temechegn

Altogether the test is made up of 40 items covering students' ability to recall definition ... confidence interval within which student have confidence in their choice of the .... is mentioned these equilibrium systems come to memory of the learner.

Conquering Credibility for Monetary Policy Under Sticky Confidence

Directory of Open Access Journals (Sweden)

Jaylson Jair da Silveira

2015-06-01

Full Text Available We derive a best-reply monetary policy when the confidence by price setters on the monetary authority’s commitment to price level targeting may be both incomplete and sticky. We find that complete confidence (or full credibility is not a necessary condition for the achievement of a price level target even when heterogeneity in firms’ price level expectations is endogenously time-varying and may emerge as a long-run equilibrium outcome. In fact, in the absence of exogenous perturbations to the dynamic of confidence building, it is the achievement of a price level target for long enough that, due to stickiness in the state of confidence, rather ensures the conquering of full credibility. This result has relevant implications for the conduct of monetary policy in pursuit of price stability. One implication is that setting a price level target matters more as a means to provide monetary policy with a sharper focus on price stability than as a device to conquer credibility. As regards the conquering of credibility for monetary policy, it turns out that actions speak louder than words, as the continuing achievement of price stability is what ultimately performs better as a confidence-building device.

Estimating temperature reactivity coefficients by experimental procedures combined with isothermal temperature coefficient measurements and dynamic identification

International Nuclear Information System (INIS)

Tsuji, Masashi; Aoki, Yukinori; Shimazu, Yoichiro; Yamasaki, Masatoshi; Hanayama, Yasushi

2006-01-01

A method to evaluate the moderator coefficient (MTC) and the Doppler coefficient through experimental procedures performed during reactor physics tests of PWR power plants is proposed. This method combines isothermal temperature coefficient (ITC) measurement experiments and reactor power transient experiments at low power conditions for dynamic identification. In the dynamic identification, either one of temperature coefficients can be determined in such a way that frequency response characteristics of the reactivity change observed by a digital reactivity meter is reproduced from measured data of neutron count rate and the average coolant temperature. The other unknown coefficient can also be determined by subtracting the coefficient obtained from the dynamic identification from ITC. As the proposed method can directly estimate the Doppler coefficient, the applicability of the conventional core design codes to predict the Doppler coefficient can be verified for new types of fuels such as mixed oxide fuels. The digital simulation study was carried out to show the feasibility of the proposed method. The numerical analysis showed that the MTC and the Doppler coefficient can be estimated accurately and even if there are uncertainties in the parameters of the reactor kinetics model, the accuracies of the estimated values are not seriously impaired. (author)

The antecedents and belief-polarized effects of thought confidence.

Science.gov (United States)

Chou, Hsuan-Yi; Lien, Nai-Hwa; Liang, Kuan-Yu

2011-01-01

This article investigates 2 possible antecedents of thought confidence and explores the effects of confidence induced before or during ad exposure. The results of the experiments indicate that both consumers' dispositional optimism and spokesperson attractiveness have significant effects on consumers' confidence in thoughts that are generated after viewing the advertisement. Higher levels of thought confidence will influence the quality of the thoughts that people generate, lead to either positively or negatively polarized message processing, and therefore induce better or worse advertising effectiveness, depending on the valence of thoughts. The authors posit the belief-polarization hypothesis to explain these findings.

Research on friction coefficient of nuclear Reactor Vessel Internals Hold Down Spring: Stress coefficient test analysis method

International Nuclear Information System (INIS)

Linjun, Xie; Guohong, Xue; Ming, Zhang

2016-01-01

Graphical abstract: HDS stress coefficient test apparatus. - Highlights: • This paper performs mathematic deduction to the physical model of Hold Down Spring (HDS), establishes a mathematic model of axial load P and stress, stress coefficient and friction coefficient and designs a set of test apparatuses for simulating the pretightening process of the HDS for the first time according to a model similarity criterion. • The mathematical relation between the load and the strain is obtained about the HDS, and the mathematical model of the stress coefficient and the friction coefficient is established. So, a set of test apparatuses for obtaining the stress coefficient is designed according to the model scaling criterion and the friction coefficient of the K1000 HDS is calculated to be 0.336 through the obtained stress coefficient. • The relation curve between the theoretical load and the friction coefficient is obtained through analysis and indicates that the change of the friction coefficient f would influence the pretightening load under the condition of designed stress. The necessary pretightening load in the design process is calculated to be 5469 kN according to the obtained friction coefficient. Therefore, the friction coefficient and the pretightening load under the design conditions can provide accurate pretightening data for the analysis and design of the reactor HDS according to the operations. - Abstract: This paper performs mathematic deduction to the physical model of Hold Down Spring (HDS), establishes a mathematic model of axial load P and stress, stress coefficient and friction coefficient and designs a set of test apparatuses for simulating the pretightening process of the HDS for the first time according to a model similarity criterion. By carrying out tests and researches through a stress testing technique, P–σ curves in loading and unloading processes of the HDS are obtained and the stress coefficient k f of the HDS is obtained. So, the

Research on friction coefficient of nuclear Reactor Vessel Internals Hold Down Spring: Stress coefficient test analysis method

Energy Technology Data Exchange (ETDEWEB)

Linjun, Xie, E-mail: linjunx@zjut.edu.cn [College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310014 (China); Guohong, Xue; Ming, Zhang [Shanghai Nuclear Engineering Research & Design Institute, Shanghai 200233 (China)

2016-08-01

Graphical abstract: HDS stress coefficient test apparatus. - Highlights: • This paper performs mathematic deduction to the physical model of Hold Down Spring (HDS), establishes a mathematic model of axial load P and stress, stress coefficient and friction coefficient and designs a set of test apparatuses for simulating the pretightening process of the HDS for the first time according to a model similarity criterion. • The mathematical relation between the load and the strain is obtained about the HDS, and the mathematical model of the stress coefficient and the friction coefficient is established. So, a set of test apparatuses for obtaining the stress coefficient is designed according to the model scaling criterion and the friction coefficient of the K1000 HDS is calculated to be 0.336 through the obtained stress coefficient. • The relation curve between the theoretical load and the friction coefficient is obtained through analysis and indicates that the change of the friction coefficient f would influence the pretightening load under the condition of designed stress. The necessary pretightening load in the design process is calculated to be 5469 kN according to the obtained friction coefficient. Therefore, the friction coefficient and the pretightening load under the design conditions can provide accurate pretightening data for the analysis and design of the reactor HDS according to the operations. - Abstract: This paper performs mathematic deduction to the physical model of Hold Down Spring (HDS), establishes a mathematic model of axial load P and stress, stress coefficient and friction coefficient and designs a set of test apparatuses for simulating the pretightening process of the HDS for the first time according to a model similarity criterion. By carrying out tests and researches through a stress testing technique, P–σ curves in loading and unloading processes of the HDS are obtained and the stress coefficient k{sub f} of the HDS is obtained. So, the

Measuring of heat transfer coefficient

DEFF Research Database (Denmark)

Henningsen, Poul; Lindegren, Maria

Subtask 3.4 Measuring of heat transfer coefficient Subtask 3.4.1 Design and setting up of tests to measure heat transfer coefficient Objective: Complementary testing methods together with the relevant experimental equipment are to be designed by the two partners involved in order to measure...... the heat transfer coefficient for a wide range of interface conditions in hot and warm forging processes. Subtask 3.4.2 Measurement of heat transfer coefficient The objective of subtask 3.4.2 is to determine heat transfer values for different interface conditions reflecting those typically operating in hot...

Clustering Coefficients for Correlation Networks

Directory of Open Access Journals (Sweden)

Naoki Masuda

2018-03-01

Full Text Available Graph theory is a useful tool for deciphering structural and functional networks of the brain on various spatial and temporal scales. The clustering coefficient quantifies the abundance of connected triangles in a network and is a major descriptive statistics of networks. For example, it finds an application in the assessment of small-worldness of brain networks, which is affected by attentional and cognitive conditions, age, psychiatric disorders and so forth. However, it remains unclear how the clustering coefficient should be measured in a correlation-based network, which is among major representations of brain networks. In the present article, we propose clustering coefficients tailored to correlation matrices. The key idea is to use three-way partial correlation or partial mutual information to measure the strength of the association between the two neighboring nodes of a focal node relative to the amount of pseudo-correlation expected from indirect paths between the nodes. Our method avoids the difficulties of previous applications of clustering coefficient (and other measures in defining correlational networks, i.e., thresholding on the correlation value, discarding of negative correlation values, the pseudo-correlation problem and full partial correlation matrices whose estimation is computationally difficult. For proof of concept, we apply the proposed clustering coefficient measures to functional magnetic resonance imaging data obtained from healthy participants of various ages and compare them with conventional clustering coefficients. We show that the clustering coefficients decline with the age. The proposed clustering coefficients are more strongly correlated with age than the conventional ones are. We also show that the local variants of the proposed clustering coefficients (i.e., abundance of triangles around a focal node are useful in characterizing individual nodes. In contrast, the conventional local clustering coefficients

Clustering Coefficients for Correlation Networks.

Science.gov (United States)

Masuda, Naoki; Sakaki, Michiko; Ezaki, Takahiro; Watanabe, Takamitsu

2018-01-01

Graph theory is a useful tool for deciphering structural and functional networks of the brain on various spatial and temporal scales. The clustering coefficient quantifies the abundance of connected triangles in a network and is a major descriptive statistics of networks. For example, it finds an application in the assessment of small-worldness of brain networks, which is affected by attentional and cognitive conditions, age, psychiatric disorders and so forth. However, it remains unclear how the clustering coefficient should be measured in a correlation-based network, which is among major representations of brain networks. In the present article, we propose clustering coefficients tailored to correlation matrices. The key idea is to use three-way partial correlation or partial mutual information to measure the strength of the association between the two neighboring nodes of a focal node relative to the amount of pseudo-correlation expected from indirect paths between the nodes. Our method avoids the difficulties of previous applications of clustering coefficient (and other) measures in defining correlational networks, i.e., thresholding on the correlation value, discarding of negative correlation values, the pseudo-correlation problem and full partial correlation matrices whose estimation is computationally difficult. For proof of concept, we apply the proposed clustering coefficient measures to functional magnetic resonance imaging data obtained from healthy participants of various ages and compare them with conventional clustering coefficients. We show that the clustering coefficients decline with the age. The proposed clustering coefficients are more strongly correlated with age than the conventional ones are. We also show that the local variants of the proposed clustering coefficients (i.e., abundance of triangles around a focal node) are useful in characterizing individual nodes. In contrast, the conventional local clustering coefficients were strongly

Clustering Coefficients for Correlation Networks

Science.gov (United States)

Masuda, Naoki; Sakaki, Michiko; Ezaki, Takahiro; Watanabe, Takamitsu

2018-01-01

Graph theory is a useful tool for deciphering structural and functional networks of the brain on various spatial and temporal scales. The clustering coefficient quantifies the abundance of connected triangles in a network and is a major descriptive statistics of networks. For example, it finds an application in the assessment of small-worldness of brain networks, which is affected by attentional and cognitive conditions, age, psychiatric disorders and so forth. However, it remains unclear how the clustering coefficient should be measured in a correlation-based network, which is among major representations of brain networks. In the present article, we propose clustering coefficients tailored to correlation matrices. The key idea is to use three-way partial correlation or partial mutual information to measure the strength of the association between the two neighboring nodes of a focal node relative to the amount of pseudo-correlation expected from indirect paths between the nodes. Our method avoids the difficulties of previous applications of clustering coefficient (and other) measures in defining correlational networks, i.e., thresholding on the correlation value, discarding of negative correlation values, the pseudo-correlation problem and full partial correlation matrices whose estimation is computationally difficult. For proof of concept, we apply the proposed clustering coefficient measures to functional magnetic resonance imaging data obtained from healthy participants of various ages and compare them with conventional clustering coefficients. We show that the clustering coefficients decline with the age. The proposed clustering coefficients are more strongly correlated with age than the conventional ones are. We also show that the local variants of the proposed clustering coefficients (i.e., abundance of triangles around a focal node) are useful in characterizing individual nodes. In contrast, the conventional local clustering coefficients were strongly

Form of multicomponent Fickian diffusion coefficients matrix

International Nuclear Information System (INIS)

Wambui Mutoru, J.; Firoozabadi, Abbas

2011-01-01

Highlights: → Irreversible thermodynamics establishes form of multicomponent diffusion coefficients. → Phenomenological coefficients and thermodynamic factors affect sign of diffusion coefficients. → Negative diagonal elements of diffusion coefficients matrix can occur in non-ideal mixtures. → Eigenvalues of the matrix of Fickian diffusion coefficients may not be all real. - Abstract: The form of multicomponent Fickian diffusion coefficients matrix in thermodynamically stable mixtures is established based on the form of phenomenological coefficients and thermodynamic factors. While phenomenological coefficients form a symmetric positive definite matrix, the determinant of thermodynamic factors matrix is positive. As a result, the Fickian diffusion coefficients matrix has a positive determinant, but its elements - including diagonal elements - can be negative. Comprehensive survey of reported diffusion coefficients data for ternary and quaternary mixtures, confirms that invariably the determinant of the Fickian diffusion coefficients matrix is positive.

Consumer’s and merchant’s confidence in internet payments

Directory of Open Access Journals (Sweden)

Franc Bračun

2003-01-01

Full Text Available Performing payment transactions over the Internet is becoming increasingly important. Whenever one interacts with others, he or she faces the problem of uncertainty because in interacting with others, one makes him or herself vulnerable, i.e. one can be betrayed. Thus, perceived risk and confidence are of fundamental importance in electronic payment transactions. A higher risk leads to greater hesitance about entering into a business relationship with a high degree of uncertainty; and therefore, to an increased need for confidence. This paper has two objectives. First, it aims to introduce and test a theoretical model that predicts consumer and merchant acceptance of the Internet payment solution by explaining the complex set of relationships among the key factors influencing confidence in electronic payment transactions. Second, the paper attempts to shed light on the complex interrelationship among confidence, control and perceived risk. An empirical study was conducted to test the proposed model using data from consumers and merchants in Slovenia. The results show how perceived risk dimensions and post-transaction control influence consumer’s and merchant’s confidence in electronic payment transactions, and the impact of confidence on the adoption of mass-market on-line payment solutions.

Non-Asymptotic Confidence Sets for Circular Means

Directory of Open Access Journals (Sweden)

Thomas Hotz

2016-10-01

Full Text Available The mean of data on the unit circle is defined as the minimizer of the average squared Euclidean distance to the data. Based on Hoeffding’s mass concentration inequalities, non-asymptotic confidence sets for circular means are constructed which are universal in the sense that they require no distributional assumptions. These are then compared with asymptotic confidence sets in simulations and for a real data set.

Methodology for building confidence measures

Science.gov (United States)

Bramson, Aaron L.

2004-04-01

This paper presents a generalized methodology for propagating known or estimated levels of individual source document truth reliability to determine the confidence level of a combined output. Initial document certainty levels are augmented by (i) combining the reliability measures of multiply sources, (ii) incorporating the truth reinforcement of related elements, and (iii) incorporating the importance of the individual elements for determining the probability of truth for the whole. The result is a measure of confidence in system output based on the establishing of links among the truth values of inputs. This methodology was developed for application to a multi-component situation awareness tool under development at the Air Force Research Laboratory in Rome, New York. Determining how improvements in data quality and the variety of documents collected affect the probability of a correct situational detection helps optimize the performance of the tool overall.

The relationship between confidence in charitable organizations and volunteering revisited

NARCIS (Netherlands)

Bekkers, René H.F.P.; Bowman, Woods

2009-01-01

Confidence in charitable organizations (charitable confidence) would seem to be an important prerequisite for philanthropic behavior. Previous research relying on cross-sectional data has suggested that volunteering promotes charitable confidence and vice versa. This research note, using new

Disconnections Between Teacher Expectations and Student Confidence in Bioethics

Science.gov (United States)

Hanegan, Nikki L.; Price, Laura; Peterson, Jeremy

2008-09-01

This study examines how student practice of scientific argumentation using socioscientific bioethics issues affects both teacher expectations of students’ general performance and student confidence in their own work. When teachers use bioethical issues in the classroom students can gain not only biology content knowledge but also important decision-making skills. Learning bioethics through scientific argumentation gives students opportunities to express their ideas, formulate educated opinions and value others’ viewpoints. Research has shown that science teachers’ expectations of student success and knowledge directly influence student achievement and confidence levels. Our study analyzes pre-course and post-course surveys completed by students enrolled in a university level bioethics course ( n = 111) and by faculty in the College of Biology and Agriculture faculty ( n = 34) based on their perceptions of student confidence. Additionally, student data were collected from classroom observations and interviews. Data analysis showed a disconnect between faculty and students perceptions of confidence for both knowledge and the use of science argumentation. Student reports of their confidence levels regarding various bioethical issues were higher than faculty reports. A further disconnect showed up between students’ preferred learning styles and the general faculty’s common teaching methods; students learned more by practicing scientific argumentation than listening to traditional lectures. Students who completed a bioethics course that included practice in scientific argumentation, significantly increased their confidence levels. This study suggests that professors’ expectations and teaching styles influence student confidence levels in both knowledge and scientific argumentation.

Family Health Histories and Their Impact on Retirement Confidence.

Science.gov (United States)

Zick, Cathleen D; Mayer, Robert N; Smith, Ken R

2015-08-01

Retirement confidence is a key social barometer. In this article, we examine how personal and parental health histories relate to working-age adults' feelings of optimism or pessimism about their overall retirement prospects. This study links survey data on retirement planning with information on respondents' own health histories and those of their parents. The multivariate models control for the respondents' socio-demographic and economic characteristics along with past retirement planning activities when estimating the relationships between family health histories and retirement confidence. Retirement confidence is inversely related to parental history of cancer and cardiovascular disease but not to personal health history. In contrast, retirement confidence is positively associated with both parents being deceased. As members of the public become increasingly aware of how genetics and other family factors affect intergenerational transmission of chronic diseases, it is likely that the link between family health histories and retirement confidence will intensify. © The Author(s) 2015.

Multivoxel neurofeedback selectively modulates confidence without changing perceptual performance

Science.gov (United States)

Cortese, Aurelio; Amano, Kaoru; Koizumi, Ai; Kawato, Mitsuo; Lau, Hakwan

2016-01-01

A central controversy in metacognition studies concerns whether subjective confidence directly reflects the reliability of perceptual or cognitive processes, as suggested by normative models based on the assumption that neural computations are generally optimal. This view enjoys popularity in the computational and animal literatures, but it has also been suggested that confidence may depend on a late-stage estimation dissociable from perceptual processes. Yet, at least in humans, experimental tools have lacked the power to resolve these issues convincingly. Here, we overcome this difficulty by using the recently developed method of decoded neurofeedback (DecNef) to systematically manipulate multivoxel correlates of confidence in a frontoparietal network. Here we report that bi-directional changes in confidence do not affect perceptual accuracy. Further psychophysical analyses rule out accounts based on simple shifts in reporting strategy. Our results provide clear neuroscientific evidence for the systematic dissociation between confidence and perceptual performance, and thereby challenge current theoretical thinking. PMID:27976739

Methodology for the Assessment of Confidence in Safety Margin for Small Break Loss of Coolant Accident Sequences

Energy Technology Data Exchange (ETDEWEB)

Nagrale, D. B.; Prasad, M.; Rao, R. S.; Gaikwad, A.J., E-mail: avinashg@aerb.gov.in [Nuclear Safety Analysis Division, Atomic Energy Regulatory Board, Mumbai (India)

2014-10-15

Deterministic Safety Analysis and Probabilistic Safety Assessment (PSA) analyses are used concurrently to assess the Nuclear Power Plant (NPP) safety. The conventional deterministic analysis is conservative. The best estimate plus uncertainty analysis is increasingly being used for deterministic calculation in NPPs. The PSA methodology aims to be as realistic as possible while integrating information about accident phenomena, plant design, operating practices, component reliability and human behaviour. The peak clad temperature (PCT) distribution provides an insight into the confidence in safety margin for an initiating event. The paper deals with the concept of calculating the peak clad temperature with 95 percent confidence and 95 percent probability (PCT{sub 95/95}) in small break loss of coolant accident (SBLOCA) and methodologies for assessing safety margin. Five input parameters mainly, nominal power level, decay power, fuel clad gap conductivity, fuel thermal conductivity and discharge coefficient, were selected. A Uniform probability density function was assigned to the uncertain parameters and these uncertainties are propagated using Latin Hypercube Sampling (LHS) technique. The sampled data for 5 parameters were randomly mixed by LHS to obtain 25 input sets. A non-core damage accident sequence was selected from the SBLOCA event tree of a typical VVER study to estimate the PCTs and safety margin. A Kolmogorov– Smirnov goodness-of-fit test was carried out for PCTs. The smallest value of safety margin would indicate the robustness of the system with 95% confidence and 95% probability. Regression analysis was also carried out using 1000 sample size for the estimating PCTs. Mean, variance and finally safety margin were analysed. (author)

Confidence Measurement in the Light of Signal Detection Theory

Directory of Open Access Journals (Sweden)

Sébastien eMassoni

2014-12-01

Full Text Available We compare three alternative methods for eliciting retrospective confidence in the context of a simple perceptual task: the Simple Confidence Rating (a direct report on a numerical scale, the Quadratic Scoring Rule (a post-wagering procedure and the Matching Probability (a generalization of the no-loss gambling method. We systematically compare the results obtained with these three rules to the theoretical confidence levels that can be inferred from performance in the perceptual task using Signal Detection Theory. We find that the Matching Probability provides better results in that respect. We conclude that Matching Probability is particularly well suited for studies of confidence that use Signal Detection Theory as a theoretical framework.

The Best Model of the Swiss Banknote Data -Validation by the 95% CI of coefficients and t-test of discriminant scores

Directory of Open Access Journals (Sweden)

Shuichi Shinmura

2016-06-01

Full Text Available The discriminant analysis is not the inferential statistics since there are no equations for standard error (SE of error rate and discriminant coefficient based on the normal distribution. In this paper, we proposed the “k-fold cross validation for small sample” and can obtain the 95% confidence interval (CI of error rates and discriminant coefficients. This method is the computer-intensive approach by statistical and mathematical programming (MP software such as JMP and LINGO. By the proposed approach, we can choose the best model with the minimum mean of error rate in the validation samples (Minimum M2 Standard. In this research, we examine the sixteen linear separable models of Swiss banknote data by eight linear discriminant functions (LDFs. M2 of the best model of Revised IP-OLDF is the smallest value of all models. We find all coefficients of six Revised IP-OLDF among sixteen models rejected by the 95% CI of discriminant coefficients (Discriminant coefficient standard. We compare t-values of the discriminant scores. The t-value of the best model has the maximum values among sixteen models (Maximum t-value Standard. Moreover, we can conclude that all standards support the best model of Revised IP-OLDF.

Correlation Between Posttraumatic Growth and Posttraumatic Stress Disorder Symptoms Based on Pearson Correlation Coefficient: A Meta-Analysis.

Science.gov (United States)

Liu, An-Nuo; Wang, Lu-Lu; Li, Hui-Ping; Gong, Juan; Liu, Xiao-Hong

2017-05-01

The literature on posttraumatic growth (PTG) is burgeoning, with the inconsistencies in the literature of the relationship between PTG and posttraumatic stress disorder (PTSD) symptoms becoming a focal point of attention. Thus, this meta-analysis aims to explore the relationship between PTG and PTSD symptoms through the Pearson correlation coefficient. A systematic search of the literature from January 1996 to November 2015 was completed. We retrieved reports on 63 studies that involved 26,951 patients. The weighted correlation coefficient revealed an effect size of 0.22 with a 95% confidence interval of 0.18 to 0.25. Meta-analysis provides evidence that PTG may be positively correlated with PTSD symptoms and that this correlation may be modified by age, trauma type, and time since trauma. Accordingly, people with high levels of PTG should not be ignored, but rather, they should continue to receive help to alleviate their PTSD symptoms.

Self-confidence, overconfidence and prenatal testosterone exposure : Evidence from the lab

NARCIS (Netherlands)

Dalton, Patricio S.; Ghosal, Sayantan

2018-01-01

This paper examines whether foetal testosterone exposure predicts the extent of confidence and over-confidence in own absolute ability in adulthood. To study this question, we elicited incentive-compatible measures of confidence and over-confidence in the lab and correlate them with measures of

Sabine absorption coefficients to random incidence absorption coefficients

DEFF Research Database (Denmark)

Jeong, Cheol-Ho

2014-01-01

into random incidence absorption coefficients for porous absorbers are investigated. Two optimization-based conversion methods are suggested: the surface impedance estimation for locally reacting absorbers and the flow resistivity estimation for extendedly reacting absorbers. The suggested conversion methods...

Robust misinterpretation of confidence intervals

NARCIS (Netherlands)

Hoekstra, Rink; Morey, Richard; Rouder, Jeffrey N.; Wagenmakers, Eric-Jan

2014-01-01

Null hypothesis significance testing (NHST) is undoubtedly the most common inferential technique used to justify claims in the social sciences. However, even staunch defenders of NHST agree that its outcomes are often misinterpreted. Confidence intervals (CIs) have frequently been proposed as a more

Estimating confidence intervals in predicted responses for oscillatory biological models.

Science.gov (United States)

St John, Peter C; Doyle, Francis J

2013-07-29

The dynamics of gene regulation play a crucial role in a cellular control: allowing the cell to express the right proteins to meet changing needs. Some needs, such as correctly anticipating the day-night cycle, require complicated oscillatory features. In the analysis of gene regulatory networks, mathematical models are frequently used to understand how a network's structure enables it to respond appropriately to external inputs. These models typically consist of a set of ordinary differential equations, describing a network of biochemical reactions, and unknown kinetic parameters, chosen such that the model best captures experimental data. However, since a model's parameter values are uncertain, and since dynamic responses to inputs are highly parameter-dependent, it is difficult to assess the confidence associated with these in silico predictions. In particular, models with complex dynamics - such as oscillations - must be fit with computationally expensive global optimization routines, and cannot take advantage of existing measures of identifiability. Despite their difficulty to model mathematically, limit cycle oscillations play a key role in many biological processes, including cell cycling, metabolism, neuron firing, and circadian rhythms. In this study, we employ an efficient parameter estimation technique to enable a bootstrap uncertainty analysis for limit cycle models. Since the primary role of systems biology models is the insight they provide on responses to rate perturbations, we extend our uncertainty analysis to include first order sensitivity coefficients. Using a literature model of circadian rhythms, we show how predictive precision is degraded with decreasing sample points and increasing relative error. Additionally, we show how this method can be used for model discrimination by comparing the output identifiability of two candidate model structures to published literature data. Our method permits modellers of oscillatory systems to confidently

Stability in the metamemory realism of eyewitness confidence judgments.

Science.gov (United States)

Buratti, Sandra; Allwood, Carl Martin; Johansson, Marcus

2014-02-01

The stability of eyewitness confidence judgments over time in regard to their reported memory and accuracy of these judgments is of interest in forensic contexts because witnesses are often interviewed many times. The present study investigated the stability of the confidence judgments of memory reports of a witnessed event and of the accuracy of these judgments over three occasions, each separated by 1 week. Three age groups were studied: younger children (8-9 years), older children (10-11 years), and adults (19-31 years). A total of 93 participants viewed a short film clip and were asked to answer directed two-alternative forced-choice questions about the film clip and to confidence judge each answer. Different questions about details in the film clip were used on each of the three test occasions. Confidence as such did not exhibit stability over time on an individual basis. However, the difference between confidence and proportion correct did exhibit stability across time, in terms of both over/underconfidence and calibration. With respect to age, the adults and older children exhibited more stability than the younger children for calibration. Furthermore, some support for instability was found with respect to the difference between the average confidence level for correct and incorrect answers (slope). Unexpectedly, however, the younger children's slope was found to be more stable than the adults. Compared to the previous research, the present study's use of more advanced statistical methods provides a more nuanced understanding of the stability of confidence judgments in the eyewitness reports of children and adults.

Nurses' training and confidence on deep venous catheterization.

Science.gov (United States)

Liachopoulou, A P; Synodinou-Kamilou, E E; Deligiannidi, P G; Giannakopoulou, M; Birbas, K N

2008-01-01

The rough estimation of the education and the self-confidence of nurses, both students and professionals, regarding deep venous catheterization in adult patients, the evaluation of the change in self-confidence of one team of students who were trained with a simulator on deep venous catheterization and the correlation of their self-confidence with their performance recorded by the simulator. Seventy-six nurses and one hundred twenty-four undergraduate students participated in the study. Fourty-four University students took part in a two-day educational seminar and were trained on subclavian and femoral vein paracentesis with a simulator and an anatomical model. Three questionnaires were filled in by the participants: one from nurses, one from students of Technological institutions, while the University students filled in the previous questionnaire before their attendance of the seminar, and another questionnaire after having attended it. Impressive results in improving the participants' self-confidence were recorded. However, the weak correlation of their self-confidence with the score automatically provided by the simulator after each user's training obligates us to be particularly cautious about the ability of the users to repeat the action successfully in a clinical environment. Educational courses and simulators are useful educational tools that are likely to shorten but in no case can efface the early phase of the learning curve in clinical setting, substituting the clinical training of inexperienced users.

Transport Coefficients of Fluids

CERN Document Server

Eu, Byung Chan

2006-01-01

Until recently the formal statistical mechanical approach offered no practicable method for computing the transport coefficients of liquids, and so most practitioners had to resort to empirical fitting formulas. This has now changed, as demonstrated in this innovative monograph. The author presents and applies new methods based on statistical mechanics for calculating the transport coefficients of simple and complex liquids over wide ranges of density and temperature. These molecular theories enable the transport coefficients to be calculated in terms of equilibrium thermodynamic properties, and the results are shown to account satisfactorily for experimental observations, including even the non-Newtonian behavior of fluids far from equilibrium.

Can confidence indicators forecast the probability of expansion in Croatia?

Directory of Open Access Journals (Sweden)

Mirjana Čižmešija

2016-04-01

Full Text Available The aim of this paper is to investigate how reliable are confidence indicators in forecasting the probability of expansion. We consider three Croatian Business Survey indicators: the Industrial Confidence Indicator (ICI, the Construction Confidence Indicator (BCI and the Retail Trade Confidence Indicator (RTCI. The quarterly data, used in the research, covered the periods from 1999/Q1 to 2014/Q1. Empirical analysis consists of two parts. The non-parametric Bry-Boschan algorithm is used for distinguishing periods of expansion from the period of recession in the Croatian economy. Then, various nonlinear probit models were estimated. The models differ with respect to the regressors (confidence indicators and the time lags. The positive signs of estimated parameters suggest that the probability of expansion increases with an increase in Confidence Indicators. Based on the obtained results, the conclusion is that ICI is the most powerful predictor of the probability of expansion in Croatia.

Modeling Confidence and Response Time in Recognition Memory

Science.gov (United States)

Ratcliff, Roger; Starns, Jeffrey J.

2009-01-01

A new model for confidence judgments in recognition memory is presented. In the model, the match between a single test item and memory produces a distribution of evidence, with better matches corresponding to distributions with higher means. On this match dimension, confidence criteria are placed, and the areas between the criteria under the…

Energy coefficients for a propeller series

DEFF Research Database (Denmark)

Olsen, Anders Smærup

2004-01-01

The efficiency for a propeller is calculated by energy coefficients. These coefficients are related to four types of losses, i.e. the axial, the rotational, the frictional, and the finite blade number loss, and one gain, i.e. the axial gain. The energy coefficients are derived by use...... of the potential theory with the propeller modelled as an actuator disk. The efficiency based on the energy coefficients is calculated for a propeller series. The results show a good agreement between the efficiency based on the energy coefficients and the efficiency obtained by a vortex-lattice method....

Meta-Analysis of the Correlation between Apparent Diffusion Coefficient and Standardized Uptake Value in Malignant Disease.

Science.gov (United States)

Deng, Shengming; Wu, Zhifang; Wu, Yiwei; Zhang, Wei; Li, Jihui; Dai, Na; Zhang, Bin; Yan, Jianhua

2017-01-01

The objective of this meta-analysis is to explore the correlation between the apparent diffusion coefficient (ADC) on diffusion-weighted MR and the standard uptake value (SUV) of 18 F-FDG on PET/CT in patients with cancer. Databases such as PubMed (MEDLINE included), EMBASE, and Cochrane Database of Systematic Review were searched for relevant original articles that explored the correlation between SUV and ADC in English. After applying Fisher's r -to- z transformation, correlation coefficient ( r ) values were extracted from each study and 95% confidence intervals (CIs) were calculated. Sensitivity and subgroup analyses based on tumor type were performed to investigate the potential heterogeneity. Forty-nine studies were eligible for the meta-analysis, comprising 1927 patients. Pooled r for all studies was -0.35 (95% CI: -0.42-0.28) and exhibited a notable heterogeneity ( I 2 = 78.4%; P correlation coefficients of ADC/SUV range from -0.12 (lymphoma, n = 5) to -0.59 (pancreatic cancer, n = 2). We concluded that there is an average negative correlation between ADC and SUV in patients with cancer. Higher correlations were found in the brain tumor, cervix carcinoma, and pancreas cancer. However, a larger, prospective study is warranted to validate these findings in different cancer types.

Contrasting Academic Behavioural Confidence in Mexican and European Psychology Students

Science.gov (United States)

Ochoa, Alma Rosa Aguila; Sander, Paul

2012-01-01

Introduction: Research with the Academic Behavioural Confidence scale using European students has shown that students have high levels of confidence in their academic abilities. It is generally accepted that people in more collectivist cultures have more realistic confidence levels in contrast to the overconfidence seen in individualistic European…

A drying coefficient for building materials

DEFF Research Database (Denmark)

Scheffler, Gregor Albrecht; Plagge, Rudolf

2009-01-01

coefficient is defined which can be determined based on measured drying data. The correlation of this coefficient with the water absorption and the vapour diffusion coefficient is analyzed and its additional information content is critically challenged. As result, a drying coefficient has been derived......The drying experiment is an important element of the hygrothermal characterisation of building materials. Contrary to other moisture transport experiments as the vapour diffusion and the water absorption test, it is until now not possible to derive a simple coefficient for the drying. However......, in many cases such a coefficient would be highly appreciated, e.g. in interaction of industry and research or for the distinction and selection of suitable building materials throughout design and practise. This article first highlights the importance of drying experiments for hygrothermal...

Market Confidence Predicts Stock Price: Beyond Supply and Demand.

Directory of Open Access Journals (Sweden)

Xiao-Qian Sun

Full Text Available Stock price prediction is an important and challenging problem in stock market analysis. Existing prediction methods either exploit autocorrelation of stock price and its correlation with the supply and demand of stock, or explore predictive indictors exogenous to stock market. In this paper, using transaction record of stocks with identifier of traders, we introduce an index to characterize market confidence, i.e., the ratio of the number of traders who is active in two successive trading days to the number of active traders in a certain trading day. Strong Granger causality is found between the index of market confidence and stock price. We further predict stock price by incorporating the index of market confidence into a neural network based on time series of stock price. Experimental results on 50 stocks in two Chinese Stock Exchanges demonstrate that the accuracy of stock price prediction is significantly improved by the inclusion of the market confidence index. This study sheds light on using cross-day trading behavior to characterize market confidence and to predict stock price.

Market Confidence Predicts Stock Price: Beyond Supply and Demand.

Science.gov (United States)

Sun, Xiao-Qian; Shen, Hua-Wei; Cheng, Xue-Qi; Zhang, Yuqing

2016-01-01

Stock price prediction is an important and challenging problem in stock market analysis. Existing prediction methods either exploit autocorrelation of stock price and its correlation with the supply and demand of stock, or explore predictive indictors exogenous to stock market. In this paper, using transaction record of stocks with identifier of traders, we introduce an index to characterize market confidence, i.e., the ratio of the number of traders who is active in two successive trading days to the number of active traders in a certain trading day. Strong Granger causality is found between the index of market confidence and stock price. We further predict stock price by incorporating the index of market confidence into a neural network based on time series of stock price. Experimental results on 50 stocks in two Chinese Stock Exchanges demonstrate that the accuracy of stock price prediction is significantly improved by the inclusion of the market confidence index. This study sheds light on using cross-day trading behavior to characterize market confidence and to predict stock price.

Confidence in leadership among the newly qualified.

Science.gov (United States)

Bayliss-Pratt, Lisa; Morley, Mary; Bagley, Liz; Alderson, Steven

2013-10-23

The Francis report highlighted the importance of strong leadership from health professionals but it is unclear how prepared those who are newly qualified feel to take on a leadership role. We aimed to assess the confidence of newly qualified health professionals working in the West Midlands in the different competencies of the NHS Leadership Framework. Most respondents felt confident in their abilities to demonstrate personal qualities and work with others, but less so at managing or improving services or setting direction.

Biased but in Doubt: Conflict and Decision Confidence

Science.gov (United States)

De Neys, Wim; Cromheeke, Sofie; Osman, Magda

2011-01-01

Human reasoning is often biased by intuitive heuristics. A central question is whether the bias results from a failure to detect that the intuitions conflict with traditional normative considerations or from a failure to discard the tempting intuitions. The present study addressed this unresolved debate by using people's decision confidence as a nonverbal index of conflict detection. Participants were asked to indicate how confident they were after solving classic base-rate (Experiment 1) and conjunction fallacy (Experiment 2) problems in which a cued intuitive response could be inconsistent or consistent with the traditional correct response. Results indicated that reasoners showed a clear confidence decrease when they gave an intuitive response that conflicted with the normative response. Contrary to popular belief, this establishes that people seem to acknowledge that their intuitive answers are not fully warranted. Experiment 3 established that younger reasoners did not yet show the confidence decrease, which points to the role of improved bias awareness in our reasoning development. Implications for the long standing debate on human rationality are discussed. PMID:21283574

"Depressive Realism" assessed via Confidence in Decision-making.

Science.gov (United States)

Hancock, J A

1996-08-01

There are two currently influential views regarding the link between cognitive distortions and depression. The first states that depressed individuals perceive the world and themselves with a strong negative bias or distortion, and that mentally healthy individuals perceive the word with relative accuracy. The second ''depressive realism'' camp argues that healthy individuals are positively biased and the depressed are relatively unbiased and hence, more realistic. In the present investigation, subjects suffering from major depression, subjects recovered from major depression, and a group of healthy controls were examined with regard to their confidence in answering each of 99 general knowledge questions. Confidence ratings were analysed separately according to correct or incorrect responses. There were no significant differences in performance (i.e. accuracy of answer between the three groups). When answering correctly, depressed subjects were significantly less confident than healthy control subjects. On answering incorrectly, none of the three groups were significantly different in their confidence ratings. These findings support the cognitive distortion view of depression and provide no evidence of ''depressive realism''.

Challenge for reconstruction of public confidence

International Nuclear Information System (INIS)

Matsuura, S.

2001-01-01

Past incidents and scandals that have had a large influence on damaging public confidence in nuclear energy safety are presented. Radiation leak on nuclear-powered ship 'Mutsu' (1974), the T.M.I. incident in 1979, Chernobyl accident (1986), the sodium leak at the Monju reactor (1995), fire and explosion at a low level waste asphalt solidification facility (1997), J.C.O. incident (Tokai- MURA, 1999), are so many examples that have created feelings of distrust and anxiety in society. In order to restore public confidence there is no other course but to be prepared for difficulty and work honestly to our fullest ability, with all steps made openly and accountably. (N.C.)

Graduating general surgery resident operative confidence: perspective from a national survey.

Science.gov (United States)

Fonseca, Annabelle L; Reddy, Vikram; Longo, Walter E; Gusberg, Richard J

2014-08-01

General surgical training has changed significantly over the last decade with work hour restrictions, increasing subspecialization, the expanding use of minimally invasive techniques, and nonoperative management for solid organ trauma. Given these changes, this study was undertaken to assess the confidence of graduating general surgery residents in performing open surgical operations and to determine factors associated with increased confidence. A survey was developed and sent to general surgery residents nationally. We queried them regarding demographics and program characteristics, asked them to rate their confidence (rated 1-5 on a Likert scale) in performing open surgical procedures and compared those who indicated confidence with those who did not. We received 653 responses from the fifth year (postgraduate year 5) surgical residents: 69% male, 68% from university programs, and 51% from programs affiliated with a Veterans Affairs hospital; 22% from small programs, 34% from medium programs, and 44% from large programs. Anticipated postresidency operative confidence was 72%. More than 25% of residents reported a lack of confidence in performing eight of the 13 operations they were queried about. Training at a university program, a large program, dedicated research years, future fellowship plans, and training at a program that performed a large percentage of operations laparoscopically was associated with decreased confidence in performing a number of open surgical procedures. Increased surgical volume was associated with increased operative confidence. Confidence in performing open surgery also varied regionally. Graduating surgical residents indicated a significant lack of confidence in performing a variety of open surgical procedures. This decreased confidence was associated with age, operative volume as well as type, and location of training program. Analyzing and addressing this confidence deficit merits further study. Copyright © 2014 Elsevier Inc. All

Alan Greenspan, the confidence strategy

Directory of Open Access Journals (Sweden)

Edwin Le Heron

2006-12-01

Full Text Available To evaluate the Greenspan era, we nevertheless need to address three questions: Is his success due to talent or just luck? Does he have a system of monetary policy or is he himself the system? What will be his legacy? Greenspan was certainly lucky, but he was also clairvoyant. Above all, he has developed a profoundly original monetary policy. His confidence strategy is clearly opposed to the credibility strategy developed in central banks and the academic milieu after 1980, but also inflation targeting, which today constitutes the mainstream monetary policy regime. The question of his legacy seems more nuanced. However, Greenspan will remain 'for a considerable period of time' a highly heterodox and original central banker. His political vision, his perception of an uncertain world, his pragmatism and his openness form the structure of a powerful alternative system, the confidence strategy, which will leave its mark on the history of monetary policy.

The Influence of Endogenous and Exogenous Spatial Attention on Decision Confidence.

Science.gov (United States)

Kurtz, Phillipp; Shapcott, Katharine A; Kaiser, Jochen; Schmiedt, Joscha T; Schmid, Michael C

2017-07-25

Spatial attention allows us to make more accurate decisions about events in our environment. Decision confidence is thought to be intimately linked to the decision making process as confidence ratings are tightly coupled to decision accuracy. While both spatial attention and decision confidence have been subjected to extensive research, surprisingly little is known about the interaction between these two processes. Since attention increases performance it might be expected that confidence would also increase. However, two studies investigating the effects of endogenous attention on decision confidence found contradictory results. Here we investigated the effects of two distinct forms of spatial attention on decision confidence; endogenous attention and exogenous attention. We used an orientation-matching task, comparing the two attention conditions (endogenous and exogenous) to a control condition without directed attention. Participants performed better under both attention conditions than in the control condition. Higher confidence ratings than the control condition were found under endogenous attention but not under exogenous attention. This finding suggests that while attention can increase confidence ratings, it must be voluntarily deployed for this increase to take place. We discuss possible implications of this relative overconfidence found only during endogenous attention with respect to the theoretical background of decision confidence.

Confidence in Numerical Simulations

International Nuclear Information System (INIS)

Hemez, Francois M.

2015-01-01

This PowerPoint presentation offers a high-level discussion of uncertainty, confidence and credibility in scientific Modeling and Simulation (M&S). It begins by briefly evoking M&S trends in computational physics and engineering. The first thrust of the discussion is to emphasize that the role of M&S in decision-making is either to support reasoning by similarity or to ''forecast,'' that is, make predictions about the future or extrapolate to settings or environments that cannot be tested experimentally. The second thrust is to explain that M&S-aided decision-making is an exercise in uncertainty management. The three broad classes of uncertainty in computational physics and engineering are variability and randomness, numerical uncertainty and model-form uncertainty. The last part of the discussion addresses how scientists ''think.'' This thought process parallels the scientific method where by a hypothesis is formulated, often accompanied by simplifying assumptions, then, physical experiments and numerical simulations are performed to confirm or reject the hypothesis. ''Confidence'' derives, not just from the levels of training and experience of analysts, but also from the rigor with which these assessments are performed, documented and peer-reviewed.

Derivation of energy-based base shear force coefficient considering hysteretic behavior and P-delta effects

Science.gov (United States)

Ucar, Taner; Merter, Onur

2018-01-01

A modified energy-balance equation accounting for P-delta effects and hysteretic behavior of reinforced concrete members is derived. Reduced hysteretic properties of structural components due to combined stiffness and strength degradation and pinching effects, and hysteretic damping are taken into account in a simple manner by utilizing plastic energy and seismic input energy modification factors. Having a pre-selected yield mechanism, energy balance of structure in inelastic range is considered. P-delta effects are included in derived equation by adding the external work of gravity loads to the work of equivalent inertia forces and equating the total external work to the modified plastic energy. Earthquake energy input to multi degree of freedom (MDOF) system is approximated by using the modal energy-decomposition. Energy-based base shear coefficients are verified by means of both pushover analysis and nonlinear time history (NLTH) analysis of several RC frames having different number of stories. NLTH analyses of frames are performed by using the time histories of ten scaled ground motions compatible with elastic design acceleration spectrum and fulfilling duration/amplitude related requirements of Turkish Seismic Design Code. The observed correlation between energy-based base shear force coefficients and the average base shear force coefficients of NLTH analyses provides a reasonable confidence in estimation of nonlinear base shear force capacity of frames by using the derived equation.

Quadrature formulas for Fourier coefficients

KAUST Repository

Bojanov, Borislav

2009-09-01

We consider quadrature formulas of high degree of precision for the computation of the Fourier coefficients in expansions of functions with respect to a system of orthogonal polynomials. In particular, we show the uniqueness of a multiple node formula for the Fourier-Tchebycheff coefficients given by Micchelli and Sharma and construct new Gaussian formulas for the Fourier coefficients of a function, based on the values of the function and its derivatives. © 2009 Elsevier B.V. All rights reserved.

A simultaneous confidence band for sparse longitudinal regression

KAUST Repository

Ma, Shujie; Yang, Lijian; Carroll, Raymond J.

2012-01-01

Functional data analysis has received considerable recent attention and a number of successful applications have been reported. In this paper, asymptotically simultaneous confidence bands are obtained for the mean function of the functional regression model, using piecewise constant spline estimation. Simulation experiments corroborate the asymptotic theory. The confidence band procedure is illustrated by analyzing CD4 cell counts of HIV infected patients.

Graphing within-subjects confidence intervals using SPSS and S-Plus.

Science.gov (United States)

Wright, Daniel B

2007-02-01

Within-subjects confidence intervals are often appropriate to report and to display. Loftus and Masson (1994) have reported methods to calculate these, and their use is becoming common. In the present article, procedures for calculating within-subjects confidence intervals in SPSS and S-Plus are presented (an R version is on the accompanying Web site). The procedure in S-Plus allows the user to report the bias corrected and adjusted bootstrap confidence intervals as well as the standard confidence intervals based on traditional methods. The presented code can be easily altered to fit the individual user's needs.

The Development of Confidence Limits for Fatigue Strength Data

International Nuclear Information System (INIS)

SUTHERLAND, HERBERT J.; VEERS, PAUL S.

1999-01-01

Over the past several years, extensive databases have been developed for the S-N behavior of various materials used in wind turbine blades, primarily fiberglass composites. These data are typically presented both in their raw form and curve fit to define their average properties. For design, confidence limits must be placed on these descriptions. In particular, most designs call for the 95/95 design values; namely, with a 95% level of confidence, the designer is assured that 95% of the material will meet or exceed the design value. For such material properties as the ultimate strength, the procedures for estimating its value at a particular confidence level is well defined if the measured values follow a normal or a log-normal distribution. Namely, based upon the number of sample points and their standard deviation, a commonly-found table may be used to determine the survival percentage at a particular confidence level with respect to its mean value. The same is true for fatigue data at a constant stress level (the number of cycles to failure N at stress level S(sub 1)). However, when the stress level is allowed to vary, as with a typical S-N fatigue curve, the procedures for determining confidence limits are not as well defined. This paper outlines techniques for determining confidence limits of fatigue data. Different approaches to estimating the 95/95 level are compared. Data from the MSU/DOE and the FACT fatigue databases are used to illustrate typical results

Nurse leader certification preparation: how are confidence levels impacted?

Science.gov (United States)

Junger, Stacey; Trinkle, Nicole; Hall, Norma

2016-09-01

The aim was to examine the effect of a nurse leader certification preparation course on the confidence levels of the participants. Limited literature is available regarding nurse leader development and certifications. Barriers exist related to lack of confidence, high cost, time and lack of access to a preparation course. Nurse leaders (n = 51) completed a pre- and post-survey addressing confidence levels of participants related to the topics addressed in the nurse leader certification preparation course. There were statistically significant increases in confidence levels related to all course content for the participants. At the time of the study, there were 31.4% of participants intending to sit for the certification examination, and 5 of the 51 participants successfully sat for and passed the examination. A nurse leader certification preparation course increases confidence levels of the participants and removes barriers, thereby increasing the number of certifications obtained. The health-care climate is increasingly complex and nurse leaders need the expertise to navigate the ever-changing health-care environment. Certification in a specialty, such as leadership, serves as an indicator of a high level of competence in the field. © 2016 John Wiley & Sons Ltd.

Confidence and the stock market: an agent-based approach.

Science.gov (United States)

Bertella, Mario A; Pires, Felipe R; Feng, Ling; Stanley, Harry Eugene

2014-01-01

Using a behavioral finance approach we study the impact of behavioral bias. We construct an artificial market consisting of fundamentalists and chartists to model the decision-making process of various agents. The agents differ in their strategies for evaluating stock prices, and exhibit differing memory lengths and confidence levels. When we increase the heterogeneity of the strategies used by the agents, in particular the memory lengths, we observe excess volatility and kurtosis, in agreement with real market fluctuations--indicating that agents in real-world financial markets exhibit widely differing memory lengths. We incorporate the behavioral traits of adaptive confidence and observe a positive correlation between average confidence and return rate, indicating that market sentiment is an important driver in price fluctuations. The introduction of market confidence increases price volatility, reflecting the negative effect of irrationality in market behavior.

Tables of Confidence Limits for Proportions

Science.gov (United States)

1990-09-01

0.972 180 49 0.319 0.332 0,357 175 165 0.964 0.969 0.976 ISO 50 0.325 0.338 0.363 175 166 0.969 0.973 0.980 180 51 0.331 0.344 0.368 175 167 0.973 0.977...0.528 180 18 0.135 0 145 0.164 180 19 0.141 0.151 0.171 ISO 80 0.495 0,508 0.534 347 UPPER CONFIDENCE LIMIT FOR PROPORTIONS CONFIDENCE LEVEL...500 409 0.8401 0.8459 0.8565 500 355 0.7364 0.7434 0.7564 500 356 0.7383 0.7453 0.7582 500 410 0.8420 0.8478 0 8583 500 357 0.7402 0.7472 0.7602 500

Decision time and confidence predict choosers' identification performance in photographic showups

Science.gov (United States)

Sagana, Anna; Sporer, Siegfried L.; Wixted, John T.

2018-01-01

In vast contrast to the multitude of lineup studies that report on the link between decision time, confidence, and identification accuracy, only a few studies looked at these associations for showups, with results varying widely across studies. We therefore set out to test the individual and combined value of decision time and post-decision confidence for diagnosing the accuracy of positive showup decisions using confidence-accuracy characteristic curves and Bayesian analyses. Three-hundred-eighty-four participants viewed a stimulus event and were subsequently presented with two showups which could be target-present or target-absent. As expected, we found a negative decision time-accuracy and a positive post-decision confidence-accuracy correlation for showup selections. Confidence-accuracy characteristic curves demonstrated the expected additive effect of combining both postdictors. Likewise, Bayesian analyses, taking into account all possible target-presence base rate values showed that fast and confident identification decisions were more diagnostic than slow or less confident decisions, with the combination of both being most diagnostic for postdicting accurate and inaccurate decisions. The postdictive value of decision time and post-decision confidence was higher when the prior probability that the suspect is the perpetrator was high compared to when the prior probability that the suspect is the perpetrator was low. The frequent use of showups in practice emphasizes the importance of these findings for court proceedings. Overall, these findings support the idea that courts should have most trust in showup identifications that were made fast and confidently, and least in showup identifications that were made slowly and with low confidence. PMID:29346394

Reproducibility of The Random Incidence Absorption Coefficient Converted From the Sabine Absorption Coefficient

DEFF Research Database (Denmark)

Jeong, Cheol-Ho; Chang, Ji-ho

2015-01-01

largely depending on the test room. Several conversion methods for porous absorbers from the Sabine absorption coefficient to the random incidence absorption coefficient were suggested by considering the finite size of a test specimen and non-uniformly incident energy onto the specimen, which turned out...... resistivity optimization outperforms the surface impedance optimization in terms of the reproducibility....

Confidence bounds of recurrence-based complexity measures

International Nuclear Information System (INIS)

Schinkel, Stefan; Marwan, N.; Dimigen, O.; Kurths, J.

2009-01-01

In the recent past, recurrence quantification analysis (RQA) has gained an increasing interest in various research areas. The complexity measures the RQA provides have been useful in describing and analysing a broad range of data. It is known to be rather robust to noise and nonstationarities. Yet, one key question in empirical research concerns the confidence bounds of measured data. In the present Letter we suggest a method for estimating the confidence bounds of recurrence-based complexity measures. We study the applicability of the suggested method with model and real-life data.

Confidence building - is science the only approach

International Nuclear Information System (INIS)

Bragg, K.

1990-01-01

The Atomic Energy Control Board (AECB) has begun to develop some simplified methods to determine if it is possible to provide confidence that dose, risk and environmental criteria can be respected without undue reliance on detailed scientific models. The progress to date will be outlined and the merits of this new approach will be compared to the more complex, traditional approach. Stress will be given to generating confidence in both technical and non-technical communities as well as the need to enhance communication between them. 3 refs., 1 tab

Inferring high-confidence human protein-protein interactions

Directory of Open Access Journals (Sweden)

Yu Xueping

2012-05-01

Full Text Available Abstract Background As numerous experimental factors drive the acquisition, identification, and interpretation of protein-protein interactions (PPIs, aggregated assemblies of human PPI data invariably contain experiment-dependent noise. Ascertaining the reliability of PPIs collected from these diverse studies and scoring them to infer high-confidence networks is a non-trivial task. Moreover, a large number of PPIs share the same number of reported occurrences, making it impossible to distinguish the reliability of these PPIs and rank-order them. For example, for the data analyzed here, we found that the majority (>83% of currently available human PPIs have been reported only once. Results In this work, we proposed an unsupervised statistical approach to score a set of diverse, experimentally identified PPIs from nine primary databases to create subsets of high-confidence human PPI networks. We evaluated this ranking method by comparing it with other methods and assessing their ability to retrieve protein associations from a number of diverse and independent reference sets. These reference sets contain known biological data that are either directly or indirectly linked to interactions between proteins. We quantified the average effect of using ranked protein interaction data to retrieve this information and showed that, when compared to randomly ranked interaction data sets, the proposed method created a larger enrichment (~134% than either ranking based on the hypergeometric test (~109% or occurrence ranking (~46%. Conclusions From our evaluations, it was clear that ranked interactions were always of value because higher-ranked PPIs had a higher likelihood of retrieving high-confidence experimental data. Reducing the noise inherent in aggregated experimental PPIs via our ranking scheme further increased the accuracy and enrichment of PPIs derived from a number of biologically relevant data sets. These results suggest that using our high-confidence

Animal Spirits and Extreme Confidence: No Guts, No Glory?

NARCIS (Netherlands)

M.G. Douwens-Zonneveld (Mariska)

2012-01-01

textabstractThis study investigates to what extent extreme confidence of either management or security analysts may impact financial or operating performance. We construct a multidimensional degree of company confidence measure from a wide range of corporate decisions. We empirically test this

Drag Coefficient Estimation in Orbit Determination

Science.gov (United States)

McLaughlin, Craig A.; Manee, Steve; Lichtenberg, Travis

2011-07-01

Drag modeling is the greatest uncertainty in the dynamics of low Earth satellite orbits where ballistic coefficient and density errors dominate drag errors. This paper examines fitted drag coefficients found as part of a precision orbit determination process for Stella, Starlette, and the GEOSAT Follow-On satellites from 2000 to 2005. The drag coefficients for the spherical Stella and Starlette satellites are assumed to be highly correlated with density model error. The results using MSIS-86, NRLMSISE-00, and NRLMSISE-00 with dynamic calibration of the atmosphere (DCA) density corrections are compared. The DCA corrections were formulated for altitudes of 200-600 km and are found to be inappropriate when applied at 800 km. The yearly mean fitted drag coefficients are calculated for each satellite for each year studied. The yearly mean drag coefficients are higher for Starlette than Stella, where Starlette is at a higher altitude. The yearly mean fitted drag coefficients for all three satellites decrease as solar activity decreases after solar maximum.

Dynamics analysis of SIR epidemic model with correlation coefficients and clustering coefficient in networks.

Science.gov (United States)

Zhang, Juping; Yang, Chan; Jin, Zhen; Li, Jia

2018-07-14

In this paper, the correlation coefficients between nodes in states are used as dynamic variables, and we construct SIR epidemic dynamic models with correlation coefficients by using the pair approximation method in static networks and dynamic networks, respectively. Considering the clustering coefficient of the network, we analytically investigate the existence and the local asymptotic stability of each equilibrium of these models and derive threshold values for the prevalence of diseases. Additionally, we obtain two equivalent epidemic thresholds in dynamic networks, which are compared with the results of the mean field equations. Copyright © 2018 Elsevier Ltd. All rights reserved.

The influence of endogenous and exogenous spatial attention on decision confidence

OpenAIRE

Kurtz, Phillipp; Shapcott, Katharine A.; Kaiser , Jochen; Schmiedt, Joscha T.; Schmid, Michael C.

2017-01-01

Spatial attention allows us to make more accurate decisions about events in our environment. Decision confidence is thought to be intimately linked to the decision making process as confidence ratings are tightly coupled to decision accuracy. While both spatial attention and decision confidence have been subjected to extensive research, surprisingly little is known about the interaction between these two processes. Since attention increases performance it might be expected that confidence wou...

Standards for Standardized Logistic Regression Coefficients

Science.gov (United States)

Menard, Scott

2011-01-01

Standardized coefficients in logistic regression analysis have the same utility as standardized coefficients in linear regression analysis. Although there has been no consensus on the best way to construct standardized logistic regression coefficients, there is now sufficient evidence to suggest a single best approach to the construction of a…

Vaccination Confidence and Parental Refusal/Delay of Early Childhood Vaccines.

Directory of Open Access Journals (Sweden)

Melissa B Gilkey

Full Text Available To support efforts to address parental hesitancy towards early childhood vaccination, we sought to validate the Vaccination Confidence Scale using data from a large, population-based sample of U.S. parents.We used weighted data from 9,354 parents who completed the 2011 National Immunization Survey. Parents reported on the immunization history of a 19- to 35-month-old child in their households. Healthcare providers then verified children's vaccination status for vaccines including measles, mumps, and rubella (MMR, varicella, and seasonal flu. We used separate multivariable logistic regression models to assess associations between parents' mean scores on the 8-item Vaccination Confidence Scale and vaccine refusal, vaccine delay, and vaccination status.A substantial minority of parents reported a history of vaccine refusal (15% or delay (27%. Vaccination confidence was negatively associated with refusal of any vaccine (odds ratio [OR] = 0.58, 95% confidence interval [CI], 0.54-0.63 as well as refusal of MMR, varicella, and flu vaccines specifically. Negative associations between vaccination confidence and measures of vaccine delay were more moderate, including delay of any vaccine (OR = 0.81, 95% CI, 0.76-0.86. Vaccination confidence was positively associated with having received vaccines, including MMR (OR = 1.53, 95% CI, 1.40-1.68, varicella (OR = 1.54, 95% CI, 1.42-1.66, and flu vaccines (OR = 1.32, 95% CI, 1.23-1.42.Vaccination confidence was consistently associated with early childhood vaccination behavior across multiple vaccine types. Our findings support expanding the application of the Vaccination Confidence Scale to measure vaccination beliefs among parents of young children.

Learning to make collective decisions: the impact of confidence escalation.

Science.gov (United States)

Mahmoodi, Ali; Bang, Dan; Ahmadabadi, Majid Nili; Bahrami, Bahador

2013-01-01

Little is known about how people learn to take into account others' opinions in joint decisions. To address this question, we combined computational and empirical approaches. Human dyads made individual and joint visual perceptual decision and rated their confidence in those decisions (data previously published). We trained a reinforcement (temporal difference) learning agent to get the participants' confidence level and learn to arrive at a dyadic decision by finding the policy that either maximized the accuracy of the model decisions or maximally conformed to the empirical dyadic decisions. When confidences were shared visually without verbal interaction, RL agents successfully captured social learning. When participants exchanged confidences visually and interacted verbally, no collective benefit was achieved and the model failed to predict the dyadic behaviour. Behaviourally, dyad members' confidence increased progressively and verbal interaction accelerated this escalation. The success of the model in drawing collective benefit from dyad members was inversely related to confidence escalation rate. The findings show an automated learning agent can, in principle, combine individual opinions and achieve collective benefit but the same agent cannot discount the escalation suggesting that one cognitive component of collective decision making in human may involve discounting of overconfidence arising from interactions.

Variation in aerodynamic coefficients with altitude

Science.gov (United States)

Shahid, Faiza; Hussain, Mukkarum; Baig, Mirza Mehmood; Haq, Ihtram ul

Precise aerodynamics performance prediction plays key role for a flying vehicle to get its mission completed within desired accuracy. Aerodynamic coefficients for same Mach number can be different at different altitude due to difference in Reynolds number. Prediction of these aerodynamics coefficients can be made through experiments, analytical solution or Computational Fluid Dynamics (CFD). Advancements in computational power have generated the concept of using CFD as a virtual Wind Tunnel (WT), hence aerodynamic performance prediction in present study is based upon CFD (numerical test rig). Simulations at different altitudes for a range of Mach numbers with zero angle of attack are performed to predict axial force coefficient behavior with altitude (Reynolds number). Similar simulations for a fixed Mach number '3' and a range of angle of attacks are also carried out to envisage the variation in normal force and pitching moment coefficients with altitude (Reynolds number). Results clearly depict that the axial force coefficient is a function of altitude (Reynolds number) and increase as altitude increases, especially for subsonic region. Variation in axial force coefficient with altitude (Reynolds number) slightly increases for larger values of angle of attacks. Normal force and pitching moment coefficients do not depend on altitude (Reynolds number) at smaller values of angle of attacks but show slight decrease as altitude increases. Present study suggests that variation of normal force and pitching moment coefficients with altitude can be neglected but the variation of axial force coefficient with altitude should be considered for vehicle fly in dense atmosphere. It is recommended to continue this study to more complex configurations for various Mach numbers with side slip and real gas effects.

Confidence-Based Learning in Investment Analysis

Science.gov (United States)

Serradell-Lopez, Enric; Lara-Navarra, Pablo; Castillo-Merino, David; González-González, Inés

The aim of this study is to determine the effectiveness of using multiple choice tests in subjects related to the administration and business management. To this end we used a multiple-choice test with specific questions to verify the extent of knowledge gained and the confidence and trust in the answers. The tests were performed in a group of 200 students at the bachelor's degree in Business Administration and Management. The analysis made have been implemented in one subject of the scope of investment analysis and measured the level of knowledge gained and the degree of trust and security in the responses at two different times of the course. The measurements have been taken into account different levels of difficulty in the questions asked and the time spent by students to complete the test. The results confirm that students are generally able to obtain more knowledge along the way and get increases in the degree of trust and confidence in the answers. It is confirmed as the difficulty level of the questions set a priori by the heads of the subjects are related to levels of security and confidence in the answers. It is estimated that the improvement in the skills learned is viewed favourably by businesses and are especially important for job placement of students.

Confidence, Visual Research, and the Aesthetic Function

Directory of Open Access Journals (Sweden)

Stan Ruecker

2007-05-01

Full Text Available The goal of this article is to identify and describe one of the primary purposes of aesthetic quality in the design of computer interfaces and visualization tools. We suggest that humanists can derive advantages in visual research by acknowledging by their efforts to advance aesthetic quality that a significant function of aesthetics in this context is to inspire the user’s confidence. This confidence typically serves to create a sense of trust in the provider of the interface or tool. In turn, this increased trust may result in an increased willingness to engage with the object, on the basis that it demonstrates an attention to detail that promises to reward increased engagement. In addition to confidence, the aesthetic may also contribute to a heightened degree of satisfaction with having spent time using or investigating the object. In the realm of interface design and visualization research, we propose that these aesthetic functions have implications not only for the quality of interactions, but also for the results of the standard measures of performance and preference.

Implications of NGA for NEHRP site coefficients

Science.gov (United States)

Borcherdt, Roger D.

2012-01-01

Three proposals are provided to update tables 11.4-1 and 11.4-2 of Minimum Design Loads for Buildings and Other Structures (7-10), by the American Society of Civil Engineers (2010) (ASCE/SEI 7-10), with site coefficients implied directly by NGA (Next Generation Attenuation) ground motion prediction equations (GMPEs). Proposals include a recommendation to use straight-line interpolation to infer site coefficients at intermediate values of ̅vs (average shear velocity). Site coefficients are recommended to ensure consistency with ASCE/SEI 7-10 MCER (Maximum Considered Earthquake) seismic-design maps and simplified site-specific design spectra procedures requiring site classes with associated tabulated site coefficients and a reference site class with unity site coefficients. Recommended site coefficients are confirmed by independent observations of average site amplification coefficients inferred with respect to an average ground condition consistent with that used for the MCER maps. The NGA coefficients recommended for consideration are implied directly by the NGA GMPEs and do not require introduction of additional models.

The Relationship Between Eyewitness Confidence and Identification Accuracy: A New Synthesis.

Science.gov (United States)

Wixted, John T; Wells, Gary L

2017-05-01

The U.S. legal system increasingly accepts the idea that the confidence expressed by an eyewitness who identified a suspect from a lineup provides little information as to the accuracy of that identification. There was a time when this pessimistic assessment was entirely reasonable because of the questionable eyewitness-identification procedures that police commonly employed. However, after more than 30 years of eyewitness-identification research, our understanding of how to properly conduct a lineup has evolved considerably, and the time seems ripe to ask how eyewitness confidence informs accuracy under more pristine testing conditions (e.g., initial, uncontaminated memory tests using fair lineups, with no lineup administrator influence, and with an immediate confidence statement). Under those conditions, mock-crime studies and police department field studies have consistently shown that, for adults, (a) confidence and accuracy are strongly related and (b) high-confidence suspect identifications are remarkably accurate. However, when certain non-pristine testing conditions prevail (e.g., when unfair lineups are used), the accuracy of even a high-confidence suspect ID is seriously compromised. Unfortunately, some jurisdictions have not yet made reforms that would create pristine testing conditions and, hence, our conclusions about the reliability of high-confidence identifications cannot yet be applied to those jurisdictions. However, understanding the information value of eyewitness confidence under pristine testing conditions can help the criminal justice system to simultaneously achieve both of its main objectives: to exonerate the innocent (by better appreciating that initial, low-confidence suspect identifications are error prone) and to convict the guilty (by better appreciating that initial, high-confidence suspect identifications are surprisingly accurate under proper testing conditions).

Experiential Education Builds Student Self-Confidence in Delivering Medication Therapy Management

Directory of Open Access Journals (Sweden)

Wendy M. Parker

2017-07-01

Full Text Available To determine the impact of advanced pharmacy practice experiences (APPE on student self-confidence related to medication therapy management (MTM, fourth-year pharmacy students were surveyed pre/post APPE to: identify exposure to MTM learning opportunities, assess knowledge of the MTM core components, and assess self-confidence performing MTM services. An anonymous electronic questionnaire administered pre/post APPE captured demographics, factors predicted to impact student self-confidence (Grade point average (GPA, work experience, exposure to MTM learning opportunities, MTM knowledge and self-confidence conducting MTM using a 5-point Likert scale (1 = Not at all Confident; 5 = Extremely Confident. Sixty-two students (26% response rate responded to the pre-APPE questionnaire and n = 44 (18% to the post-APPE. Over 90% demonstrated MTM knowledge and 68.2% completed MTM learning activities. APPE experiences significantly improved students’ overall self-confidence (pre-APPE = 3.27 (0.85 SD, post-APPE = 4.02 (0.88, p < 0.001. Students engaging in MTM learning opportunities had higher self-confidence post-APPE (4.20 (0.71 vs. those not reporting MTM learning opportunities (3.64 (1.08, p = 0.05. Post-APPE, fewer students reported MTM was patient-centric or anticipated engaging in MTM post-graduation. APPE learning opportunities increased student self-confidence to provide MTM services. However, the reduction in anticipated engagement in MTM post-graduation and reduction in sensing the patient-centric nature of MTM practice, may reveal a gap between practice expectations and reality.

Confidence intervals for distinguishing ordinal and disordinal interactions in multiple regression.

Science.gov (United States)

Lee, Sunbok; Lei, Man-Kit; Brody, Gene H

2015-06-01

Distinguishing between ordinal and disordinal interaction in multiple regression is useful in testing many interesting theoretical hypotheses. Because the distinction is made based on the location of a crossover point of 2 simple regression lines, confidence intervals of the crossover point can be used to distinguish ordinal and disordinal interactions. This study examined 2 factors that need to be considered in constructing confidence intervals of the crossover point: (a) the assumption about the sampling distribution of the crossover point, and (b) the possibility of abnormally wide confidence intervals for the crossover point. A Monte Carlo simulation study was conducted to compare 6 different methods for constructing confidence intervals of the crossover point in terms of the coverage rate, the proportion of true values that fall to the left or right of the confidence intervals, and the average width of the confidence intervals. The methods include the reparameterization, delta, Fieller, basic bootstrap, percentile bootstrap, and bias-corrected accelerated bootstrap methods. The results of our Monte Carlo simulation study suggest that statistical inference using confidence intervals to distinguish ordinal and disordinal interaction requires sample sizes more than 500 to be able to provide sufficiently narrow confidence intervals to identify the location of the crossover point. (c) 2015 APA, all rights reserved).

Determining the confidence levels of sensor outputs using neural networks

Energy Technology Data Exchange (ETDEWEB)

Broten, G S; Wood, H C [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Electrical Engineering

1996-12-31

This paper describes an approach for determining the confidence level of a sensor output using multi-sensor arrays, sensor fusion and artificial neural networks. The authors have shown in previous work that sensor fusion and artificial neural networks can be used to learn the relationships between the outputs of an array of simulated partially selective sensors and the individual analyte concentrations in a mixture of analyses. Other researchers have shown that an array of partially selective sensors can be used to determine the individual gas concentrations in a gaseous mixture. The research reported in this paper shows that it is possible to extract confidence level information from an array of partially selective sensors using artificial neural networks. The confidence level of a sensor output is defined as a numeric value, ranging from 0% to 100%, that indicates the confidence associated with a output of a given sensor. A three layer back-propagation neural network was trained on a subset of the sensor confidence level space, and was tested for its ability to generalize, where the confidence level space is defined as all possible deviations from the correct sensor output. A learning rate of 0.1 was used and no momentum terms were used in the neural network. This research has shown that an artificial neural network can accurately estimate the confidence level of individual sensors in an array of partially selective sensors. This research has also shown that the neural network`s ability to determine the confidence level is influenced by the complexity of the sensor`s response and that the neural network is able to estimate the confidence levels even if more than one sensor is in error. The fundamentals behind this research could be applied to other configurations besides arrays of partially selective sensors, such as an array of sensors separated spatially. An example of such a configuration could be an array of temperature sensors in a tank that is not in

Determining the confidence levels of sensor outputs using neural networks

International Nuclear Information System (INIS)

Broten, G.S.; Wood, H.C.

1995-01-01

This paper describes an approach for determining the confidence level of a sensor output using multi-sensor arrays, sensor fusion and artificial neural networks. The authors have shown in previous work that sensor fusion and artificial neural networks can be used to learn the relationships between the outputs of an array of simulated partially selective sensors and the individual analyte concentrations in a mixture of analyses. Other researchers have shown that an array of partially selective sensors can be used to determine the individual gas concentrations in a gaseous mixture. The research reported in this paper shows that it is possible to extract confidence level information from an array of partially selective sensors using artificial neural networks. The confidence level of a sensor output is defined as a numeric value, ranging from 0% to 100%, that indicates the confidence associated with a output of a given sensor. A three layer back-propagation neural network was trained on a subset of the sensor confidence level space, and was tested for its ability to generalize, where the confidence level space is defined as all possible deviations from the correct sensor output. A learning rate of 0.1 was used and no momentum terms were used in the neural network. This research has shown that an artificial neural network can accurately estimate the confidence level of individual sensors in an array of partially selective sensors. This research has also shown that the neural network's ability to determine the confidence level is influenced by the complexity of the sensor's response and that the neural network is able to estimate the confidence levels even if more than one sensor is in error. The fundamentals behind this research could be applied to other configurations besides arrays of partially selective sensors, such as an array of sensors separated spatially. An example of such a configuration could be an array of temperature sensors in a tank that is not in

Probabilistic optimization of safety coefficients

International Nuclear Information System (INIS)

Marques, M.; Devictor, N.; Magistris, F. de

1999-01-01

This article describes a reliability-based method for the optimization of safety coefficients defined and used in design codes. The purpose of the optimization is to determine the partial safety coefficients which minimize an objective function for sets of components and loading situations covered by a design rule. This objective function is a sum of distances between the reliability of the components designed using the safety coefficients and a target reliability. The advantage of this method is shown on the examples of the reactor vessel, a vapour pipe and the safety injection circuit. (authors)

Estimation of the simple correlation coefficient.

Science.gov (United States)

Shieh, Gwowen

2010-11-01

This article investigates some unfamiliar properties of the Pearson product-moment correlation coefficient for the estimation of simple correlation coefficient. Although Pearson's r is biased, except for limited situations, and the minimum variance unbiased estimator has been proposed in the literature, researchers routinely employ the sample correlation coefficient in their practical applications, because of its simplicity and popularity. In order to support such practice, this study examines the mean squared errors of r and several prominent formulas. The results reveal specific situations in which the sample correlation coefficient performs better than the unbiased and nearly unbiased estimators, facilitating recommendation of r as an effect size index for the strength of linear association between two variables. In addition, related issues of estimating the squared simple correlation coefficient are also considered.

Variation in aerodynamic coefficients with altitude

Directory of Open Access Journals (Sweden)

Faiza Shahid

Full Text Available Precise aerodynamics performance prediction plays key role for a flying vehicle to get its mission completed within desired accuracy. Aerodynamic coefficients for same Mach number can be different at different altitude due to difference in Reynolds number. Prediction of these aerodynamics coefficients can be made through experiments, analytical solution or Computational Fluid Dynamics (CFD. Advancements in computational power have generated the concept of using CFD as a virtual Wind Tunnel (WT, hence aerodynamic performance prediction in present study is based upon CFD (numerical test rig. Simulations at different altitudes for a range of Mach numbers with zero angle of attack are performed to predict axial force coefficient behavior with altitude (Reynolds number. Similar simulations for a fixed Mach number ‘3’ and a range of angle of attacks are also carried out to envisage the variation in normal force and pitching moment coefficients with altitude (Reynolds number. Results clearly depict that the axial force coefficient is a function of altitude (Reynolds number and increase as altitude increases, especially for subsonic region. Variation in axial force coefficient with altitude (Reynolds number slightly increases for larger values of angle of attacks. Normal force and pitching moment coefficients do not depend on altitude (Reynolds number at smaller values of angle of attacks but show slight decrease as altitude increases. Present study suggests that variation of normal force and pitching moment coefficients with altitude can be neglected but the variation of axial force coefficient with altitude should be considered for vehicle fly in dense atmosphere. It is recommended to continue this study to more complex configurations for various Mach numbers with side slip and real gas effects. Keywords: Mach number, Reynolds number, Blunt body, Altitude effect, Angle of attacks

Anomalous Seebeck coefficient in boron carbides

International Nuclear Information System (INIS)

Aselage, T.L.; Emin, D.; Wood, C.; Mackinnon, I.D.R.; Howard, I.A.

1987-01-01

Boron carbides exhibit an anomalously large Seebeck coefficient with a temperature coefficient that is characteristic of polaronic hopping between inequivalent sites. The inequivalence in the sites is associated with disorder in the solid. The temperature dependence of the Seebeck coefficient for materials prepared by different techniques provides insight into the nature of the disorder

The Sense of Confidence during Probabilistic Learning: A Normative Account.

Directory of Open Access Journals (Sweden)

Florent Meyniel

2015-06-01

Full Text Available Learning in a stochastic environment consists of estimating a model from a limited amount of noisy data, and is therefore inherently uncertain. However, many classical models reduce the learning process to the updating of parameter estimates and neglect the fact that learning is also frequently accompanied by a variable "feeling of knowing" or confidence. The characteristics and the origin of these subjective confidence estimates thus remain largely unknown. Here we investigate whether, during learning, humans not only infer a model of their environment, but also derive an accurate sense of confidence from their inferences. In our experiment, humans estimated the transition probabilities between two visual or auditory stimuli in a changing environment, and reported their mean estimate and their confidence in this report. To formalize the link between both kinds of estimate and assess their accuracy in comparison to a normative reference, we derive the optimal inference strategy for our task. Our results indicate that subjects accurately track the likelihood that their inferences are correct. Learning and estimating confidence in what has been learned appear to be two intimately related abilities, suggesting that they arise from a single inference process. We show that human performance matches several properties of the optimal probabilistic inference. In particular, subjective confidence is impacted by environmental uncertainty, both at the first level (uncertainty in stimulus occurrence given the inferred stochastic characteristics and at the second level (uncertainty due to unexpected changes in these stochastic characteristics. Confidence also increases appropriately with the number of observations within stable periods. Our results support the idea that humans possess a quantitative sense of confidence in their inferences about abstract non-sensory parameters of the environment. This ability cannot be reduced to simple heuristics, it seems

Brain networks for confidence weighting and hierarchical inference during probabilistic learning.

Science.gov (United States)

Meyniel, Florent; Dehaene, Stanislas

2017-05-09

Learning is difficult when the world fluctuates randomly and ceaselessly. Classical learning algorithms, such as the delta rule with constant learning rate, are not optimal. Mathematically, the optimal learning rule requires weighting prior knowledge and incoming evidence according to their respective reliabilities. This "confidence weighting" implies the maintenance of an accurate estimate of the reliability of what has been learned. Here, using fMRI and an ideal-observer analysis, we demonstrate that the brain's learning algorithm relies on confidence weighting. While in the fMRI scanner, human adults attempted to learn the transition probabilities underlying an auditory or visual sequence, and reported their confidence in those estimates. They knew that these transition probabilities could change simultaneously at unpredicted moments, and therefore that the learning problem was inherently hierarchical. Subjective confidence reports tightly followed the predictions derived from the ideal observer. In particular, subjects managed to attach distinct levels of confidence to each learned transition probability, as required by Bayes-optimal inference. Distinct brain areas tracked the likelihood of new observations given current predictions, and the confidence in those predictions. Both signals were combined in the right inferior frontal gyrus, where they operated in agreement with the confidence-weighting model. This brain region also presented signatures of a hierarchical process that disentangles distinct sources of uncertainty. Together, our results provide evidence that the sense of confidence is an essential ingredient of probabilistic learning in the human brain, and that the right inferior frontal gyrus hosts a confidence-based statistical learning algorithm for auditory and visual sequences.

Brain networks for confidence weighting and hierarchical inference during probabilistic learning

Science.gov (United States)

Meyniel, Florent; Dehaene, Stanislas

2017-01-01

Learning is difficult when the world fluctuates randomly and ceaselessly. Classical learning algorithms, such as the delta rule with constant learning rate, are not optimal. Mathematically, the optimal learning rule requires weighting prior knowledge and incoming evidence according to their respective reliabilities. This “confidence weighting” implies the maintenance of an accurate estimate of the reliability of what has been learned. Here, using fMRI and an ideal-observer analysis, we demonstrate that the brain’s learning algorithm relies on confidence weighting. While in the fMRI scanner, human adults attempted to learn the transition probabilities underlying an auditory or visual sequence, and reported their confidence in those estimates. They knew that these transition probabilities could change simultaneously at unpredicted moments, and therefore that the learning problem was inherently hierarchical. Subjective confidence reports tightly followed the predictions derived from the ideal observer. In particular, subjects managed to attach distinct levels of confidence to each learned transition probability, as required by Bayes-optimal inference. Distinct brain areas tracked the likelihood of new observations given current predictions, and the confidence in those predictions. Both signals were combined in the right inferior frontal gyrus, where they operated in agreement with the confidence-weighting model. This brain region also presented signatures of a hierarchical process that disentangles distinct sources of uncertainty. Together, our results provide evidence that the sense of confidence is an essential ingredient of probabilistic learning in the human brain, and that the right inferior frontal gyrus hosts a confidence-based statistical learning algorithm for auditory and visual sequences. PMID:28439014

Meta-Analysis of the Correlation between Apparent Diffusion Coefficient and Standardized Uptake Value in Malignant Disease

Directory of Open Access Journals (Sweden)

Shengming Deng

2017-01-01

Full Text Available The objective of this meta-analysis is to explore the correlation between the apparent diffusion coefficient (ADC on diffusion-weighted MR and the standard uptake value (SUV of 18F-FDG on PET/CT in patients with cancer. Databases such as PubMed (MEDLINE included, EMBASE, and Cochrane Database of Systematic Review were searched for relevant original articles that explored the correlation between SUV and ADC in English. After applying Fisher’s r-to-z transformation, correlation coefficient (r values were extracted from each study and 95% confidence intervals (CIs were calculated. Sensitivity and subgroup analyses based on tumor type were performed to investigate the potential heterogeneity. Forty-nine studies were eligible for the meta-analysis, comprising 1927 patients. Pooled r for all studies was −0.35 (95% CI: −0.42–0.28 and exhibited a notable heterogeneity (I2 = 78.4%; P < 0.01. In terms of the cancer type subgroup analysis, combined correlation coefficients of ADC/SUV range from −0.12 (lymphoma, n = 5 to −0.59 (pancreatic cancer, n = 2. We concluded that there is an average negative correlation between ADC and SUV in patients with cancer. Higher correlations were found in the brain tumor, cervix carcinoma, and pancreas cancer. However, a larger, prospective study is warranted to validate these findings in different cancer types.

Gini coefficient as a life table function

Directory of Open Access Journals (Sweden)

2003-06-01

Full Text Available This paper presents a toolkit for measuring and analyzing inter-individual inequality in length of life by Gini coefficient. Gini coefficient and four other inequality measures are defined on the length-of-life distribution. Properties of these measures and their empirical testing on mortality data suggest a possibility for different judgements about the direction of changes in the degree of inequality by using different measures. A new computational procedure for the estimation of Gini coefficient from life tables is developed and tested on about four hundred real life tables. The estimates of Gini coefficient are precise enough even for abridged life tables with the final age group of 85+. New formulae have been developed for the decomposition of differences between Gini coefficients by age and cause of death. A new method for decomposition of age-components into effects of mortality and composition of population by group is developed. Temporal changes in the effects of elimination of causes of death on Gini coefficient are analyzed. Numerous empirical examples show: Lorenz curves for Sweden, Russia and Bangladesh in 1995, proportional changes in Gini coefficient and four other measures of inequality for the USA in 1950-1995 and for Russia in 1959-2000. Further shown are errors of estimates of Gini coefficient when computed from various types of mortality data of France, Japan, Sweden and the USA in 1900-95, decompositions of the USA-UK difference in life expectancies and Gini coefficients by age and cause of death in 1997. As well, effects of elimination of major causes of death in the UK in 1951-96 on Gini coefficient, age-specific effects of mortality and educational composition of the Russian population on changes in life expectancy and Gini coefficient between 1979 and 1989. Illustrated as well are variations in life expectancy and Gini coefficient across 32 countries in 1996-1999 and associated changes in life expectancy and Gini

Confidence assessment. Site descriptive modelling SDM-Site Forsmark

International Nuclear Information System (INIS)

2008-09-01

The objective of this report is to assess the confidence that can be placed in the Forsmark site descriptive model, based on the information available at the conclusion of the surface-based investigations (SDM-Site Forsmark). In this exploration, an overriding question is whether remaining uncertainties are significant for repository engineering design or long-term safety assessment and could successfully be further reduced by more surface based investigations or more usefully by explorations underground made during construction of the repository. The confidence in the Forsmark site descriptive model, based on the data available at the conclusion of the surface-based site investigations, have been assessed by exploring: Confidence in the site characterisation data base; Key remaining issues and their handling; Handling of alternative models; Consistency between disciplines; and, Main reasons for confidence and lack of confidence in the model. It is generally found that the key aspects of importance for safety assessment and repository engineering of the Forsmark site descriptive model are associated with a high degree of confidence. Because of the robust geological model that describes the site, the overall confidence in Forsmark site descriptive model is judged to be high. While some aspects have lower confidence this lack of confidence is handled by providing wider uncertainty ranges, bounding estimates and/or alternative models. Most, but not all, of the low confidence aspects have little impact on repository engineering design or for long-term safety. Poor precision in the measured data are judged to have limited impact on uncertainties on the site descriptive model, with the exceptions of inaccuracy in determining the position of some boreholes at depth in 3-D space, as well as the poor precision of the orientation of BIPS images in some boreholes, and the poor precision of stress data determined by overcoring at the locations where the pre

Monitoring consumer confidence in food safety: an exploratory study

NARCIS (Netherlands)

Jonge, de J.; Frewer, L.J.; Trijp, van J.C.M.; Renes, R.J.; Wit, de W.; Timmers, J.C.M.

2004-01-01

Abstract: In response to the potential for negative economic and societal effects resulting from a low level of consumer confidence in food safety, it is important to know how confidence is potentially influenced by external events. The aim of this article is to describe the development of a monitor

Differentially Private Confidence Intervals for Empirical Risk Minimization

OpenAIRE

Wang, Yue; Kifer, Daniel; Lee, Jaewoo

2018-01-01

The process of data mining with differential privacy produces results that are affected by two types of noise: sampling noise due to data collection and privacy noise that is designed to prevent the reconstruction of sensitive information. In this paper, we consider the problem of designing confidence intervals for the parameters of a variety of differentially private machine learning models. The algorithms can provide confidence intervals that satisfy differential privacy (as well as the mor...

Determination of the surface drag coefficient

DEFF Research Database (Denmark)

Mahrt, L.; Vickers, D.; Sun, J.L.

2001-01-01

This study examines the dependence of the surface drag coefficient on stability, wind speed, mesoscale modulation of the turbulent flux and method of calculation of the drag coefficient. Data sets over grassland, sparse grass, heather and two forest sites are analyzed. For significantly unstable...... conditions, the drag coefficient does not depend systematically on z/L but decreases with wind speed for fixed intervals of z/L, where L is the Obukhov length. Even though the drag coefficient for weak wind conditions is sensitive to the exact method of calculation and choice of averaging time, the decrease...... of the drag coefficient with wind speed occurs for all of the calculation methods. A classification of flux calculation methods is constructed, which unifies the most common previous approaches. The roughness length corresponding to the usual Monin-Obukhov stability functions decreases with increasing wind...

Thought confidence as a determinant of persuasion: the self-validation hypothesis.

Science.gov (United States)

Petty, Richard E; Briñol, Pablo; Tormala, Zakary L

2002-05-01

Previous research in the domain of attitude change has described 2 primary dimensions of thinking that impact persuasion processes and outcomes: the extent (amount) of thinking and the direction (valence) of issue-relevant thought. The authors examined the possibility that another, more meta-cognitive aspect of thinking is also important-the degree of confidence people have in their own thoughts. Four studies test the notion that thought confidence affects the extent of persuasion. When positive thoughts dominate in response to a message, increasing confidence in those thoughts increases persuasion, but when negative thoughts dominate, increasing confidence decreases persuasion. In addition, using self-reported and manipulated thought confidence in separate studies, the authors provide evidence that the magnitude of the attitude-thought relationship depends on the confidence people have in their thoughts. Finally, the authors also show that these self-validation effects are most likely in situations that foster high amounts of information processing activity.

True and False Memories, Parietal Cortex, and Confidence Judgments

Science.gov (United States)

Urgolites, Zhisen J.; Smith, Christine N.; Squire, Larry R.

2015-01-01

Recent studies have asked whether activity in the medial temporal lobe (MTL) and the neocortex can distinguish true memory from false memory. A frequent complication has been that the confidence associated with correct memory judgments (true memory) is typically higher than the confidence associated with incorrect memory judgments (false memory).…

Study of transport coefficients of nanodiamond nanofluids

Science.gov (United States)

Pryazhnikov, M. I.; Minakov, A. V.; Guzei, D. V.

2017-09-01

Experimental data on the thermal conductivity coefficient and viscosity coefficient of nanodiamond nanofluids are presented. Distilled water and ethylene glycol were used as the base fluid. Dependences of transport coefficients on concentration are obtained. It was shown that the thermal conductivity coefficient increases with increasing nanodiamonds concentration. It was shown that base fluids properties and nanodiamonds concentration affect on the rheology of nanofluids.

Statistical analysis of solid waste composition data: Arithmetic mean, standard deviation and correlation coefficients

DEFF Research Database (Denmark)

Edjabou, Maklawe Essonanawe; Martín-Fernández, Josep Antoni; Scheutz, Charlotte

2017-01-01

-derived food waste amounted to 2.21 ± 3.12% with a confidence interval of (−4.03; 8.45), which highlights the problem of the biased negative proportions. A Pearson’s correlation test, applied to waste fraction generation (kg mass), indicated a positive correlation between avoidable vegetable food waste...... and plastic packaging. However, correlation tests applied to waste fraction compositions (percentage values) showed a negative association in this regard, thus demonstrating that statistical analyses applied to compositional waste fraction data, without addressing the closed characteristics of these data......, have the potential to generate spurious or misleading results. Therefore, ¨compositional data should be transformed adequately prior to any statistical analysis, such as computing mean, standard deviation and correlation coefficients....

Building and strengthening confidence and security in Asia

International Nuclear Information System (INIS)

Corden, P.S.

1992-01-01

This paper presents a few thoughts on the question of building and strengthening confidence and security in Asia, in particular in the area centred on the Korean peninsula. This question includes the process of establishing and implementing confidence- and security-building measures, some of which might involve States other than North and South Korea. The development of CSBMs has now been well established in Europe, and there are encouraging signs that such measures are taking hold in other areas of the world, including in Korea. Consequently there is a fairly rich mine of information, precedent and experience from which to draw in focusing on the particular subject at hand. In these remarks the concept of confidence- and security-building is briefly addressed and measures are examined that have proven useful in other circumstances and review some possibilities that appear of interest in the present context

The integrated model of sport confidence: a canonical correlation and mediational analysis.

Science.gov (United States)

Koehn, Stefan; Pearce, Alan J; Morris, Tony

2013-12-01

The main purpose of the study was to examine crucial parts of Vealey's (2001) integrated framework hypothesizing that sport confidence is a mediating variable between sources of sport confidence (including achievement, self-regulation, and social climate) and athletes' affect in competition. The sample consisted of 386 athletes, who completed the Sources of Sport Confidence Questionnaire, Trait Sport Confidence Inventory, and Dispositional Flow Scale-2. Canonical correlation analysis revealed a confidence-achievement dimension underlying flow. Bias-corrected bootstrap confidence intervals in AMOS 20.0 were used in examining mediation effects between source domains and dispositional flow. Results showed that sport confidence partially mediated the relationship between achievement and self-regulation domains and flow, whereas no significant mediation was found for social climate. On a subscale level, full mediation models emerged for achievement and flow dimensions of challenge-skills balance, clear goals, and concentration on the task at hand.

Meta-Analysis of Coefficient Alpha

Science.gov (United States)

Rodriguez, Michael C.; Maeda, Yukiko

2006-01-01

The meta-analysis of coefficient alpha across many studies is becoming more common in psychology by a methodology labeled reliability generalization. Existing reliability generalization studies have not used the sampling distribution of coefficient alpha for precision weighting and other common meta-analytic procedures. A framework is provided for…

Analysis of internal conversion coefficients

International Nuclear Information System (INIS)

Coursol, N.; Gorozhankin, V.M.; Yakushev, E.A.; Briancon, C.; Vylov, Ts.

2000-01-01

An extensive database has been assembled that contains the three most widely used sets of calculated internal conversion coefficients (ICC): [Hager R.S., Seltzer E.C., 1968. Internal conversion tables. K-, L-, M-shell Conversion coefficients for Z=30 to Z=103, Nucl. Data Tables A4, 1-237; Band I.M., Trzhaskovskaya M.B., 1978. Tables of gamma-ray internal conversion coefficients for the K-, L- and M-shells, 10≤Z≤104, Special Report of Leningrad Nuclear Physics Institute; Roesel F., Fries H.M., Alder K., Pauli H.C., 1978. Internal conversion coefficients for all atomic shells, At. Data Nucl. Data Tables 21, 91-289] and also includes new Dirac-Fock calculations [Band I.M. and Trzhaskovskaya M.B., 1993. Internal conversion coefficients for low-energy nuclear transitions, At. Data Nucl. Data Tables 55, 43-61]. This database is linked to a computer program to plot ICCs and their combinations (sums and ratios) as a function of Z and energy, as well as relative deviations of ICC or their combinations for any pair of tabulated data. Examples of these analyses are presented for the K-shell and total ICCs of the gamma-ray standards [Hansen H.H., 1985. Evaluation of K-shell and total internal conversion coefficients for some selected nuclear transitions, Eur. Appl. Res. Rept. Nucl. Sci. Tech. 11.6 (4) 777-816] and for the K-shell and total ICCs of high multipolarity transitions (total, K-, L-, M-shells of E3 and M3 and K-shell of M4). Experimental data sets are also compared with the theoretical values of these specific calculations

SOCIAL MEDIA – VITAL INSTRUMENT IN GAINING CONSUMERS CONFIDENCE

Directory of Open Access Journals (Sweden)

Mirela-Cristina VOICU

2016-06-01

Full Text Available Given that, currently, the consumer has become more demanding and organizations face some of the greatest challenges due to the economic climate of recent years, the need to build and cultivate strong relationships has become vital not only for the company's success but also for its survival. And solid relationships are built over time through confidence. Trust is one of the most important elements in the process of purchasing and consumer loyalty; it is difficult to obtain but easy to lose. Companies that are enjoying a high degree of confidence benefit from best quotations for their shares, higher profits and a better retention of the best employees. The effects of the lack of confidence are obvious (unsatisfied consumers, lost sales and very expensive for the company. In this context, through the following paper we seek to bring more understanding on how a company can gain the confidence of consumers given that the forms of communication that consumers prefer and that are gaining momentum currently, are taking place online, especially in the social media.

Workshop on confidence limits. Proceedings

International Nuclear Information System (INIS)

James, F.; Lyons, L.; Perrin, Y.

2000-01-01

The First Workshop on Confidence Limits was held at CERN on 17-18 January 2000. It was devoted to the problem of setting confidence limits in difficult cases: number of observed events is small or zero, background is larger than signal, background not well known, and measurements near a physical boundary. Among the many examples in high-energy physics are searches for the Higgs, searches for neutrino oscillations, B s mixing, SUSY, compositeness, neutrino masses, and dark matter. Several different methods are on the market: the CL s methods used by the LEP Higgs searches; Bayesian methods; Feldman-Cousins and modifications thereof; empirical and combined methods. The Workshop generated considerable interest, and attendance was finally limited by the seating capacity of the CERN Council Chamber where all the sessions took place. These proceedings contain all the papers presented, as well as the full text of the discussions after each paper and of course the last session which was a discussion session. The list of participants and the 'required reading', which was expected to be part of the prior knowledge of all participants, are also included. (orig.)

Measuring Resource Inequality: The Gini Coefficient

Directory of Open Access Journals (Sweden)

Michael T. Catalano

2009-07-01

Full Text Available This paper stems from work done by the authors at the Mathematics for Social Justice Workshop held in June of 2007 at Middlebury College. We provide a description of the Gini coefficient and some discussion of how it can be used to promote quantitative literacy skills in mathematics courses. The Gini Coefficient was introduced in 1921 by Italian statistician Corrado Gini as a measure of inequality. It is defined as twice the area between two curves. One, the Lorenz curve for a given population with respect to a given resource, represents the cumulative percentage of the resource as a function of the cumulative percentage of the population that shares that percentage of the resource. The second curve is the line y = x which is the Lorenz curve for a population which shares the resource equally. The Gini coefficient can be interpreted as the percentage of inequality represented in the population with respect to the given resource. We propose that the Gini coefficient can be used to enhance students’ understanding of calculus concepts and provide practice for students in using both calculus and quantitative literacy skills. Our examples are based mainly on distribution of energy resources using publicly available data from the Energy Information Agency of the United States Government. For energy resources within the United States, we find that by household, the Gini coefficient is 0.346, while using the 51 data points represented by the states and Washington D.C., the Gini coefficient is 0.158. When we consider the countries of the world as a population of 210, the Gini coefficient is 0.670. We close with ideas for questions which can be posed to students and discussion of the experiences two other mathematics instructors have had incorporating the Gini coefficient into pre-calculus-level mathematics classes.

Revised Mark 22 coolant temperature coefficients

International Nuclear Information System (INIS)

Graves, W.E.

1987-01-01

Coolant temperature coefficients for the Mark 22 charge published previously are non-conservative because of the neglect of a significant mechanism which has a positive contribution to reactivity. Even after correcting for this effect, dynamic tests made on a Mark VIB charge in the early 60's suggest the results are still non-conservative. This memorandum takes both of these sources of information into account in making a best estimate of the prompt (coolant plus metal) temperature coefficient. Although no safety issues arise from this work (the overall temperature coefficient still strongly contributes to reactor stability), it is obviously desirable to use best estimates for prompt coefficients in limits and other calculations

Transport Coefficients from Large Deviation Functions

Directory of Open Access Journals (Sweden)

Chloe Ya Gao

2017-10-01

Full Text Available We describe a method for computing transport coefficients from the direct evaluation of large deviation functions. This method is general, relying on only equilibrium fluctuations, and is statistically efficient, employing trajectory based importance sampling. Equilibrium fluctuations of molecular currents are characterized by their large deviation functions, which are scaled cumulant generating functions analogous to the free energies. A diffusion Monte Carlo algorithm is used to evaluate the large deviation functions, from which arbitrary transport coefficients are derivable. We find significant statistical improvement over traditional Green–Kubo based calculations. The systematic and statistical errors of this method are analyzed in the context of specific transport coefficient calculations, including the shear viscosity, interfacial friction coefficient, and thermal conductivity.

Transport Coefficients from Large Deviation Functions

Science.gov (United States)

Gao, Chloe; Limmer, David

2017-10-01

We describe a method for computing transport coefficients from the direct evaluation of large deviation function. This method is general, relying on only equilibrium fluctuations, and is statistically efficient, employing trajectory based importance sampling. Equilibrium fluctuations of molecular currents are characterized by their large deviation functions, which is a scaled cumulant generating function analogous to the free energy. A diffusion Monte Carlo algorithm is used to evaluate the large deviation functions, from which arbitrary transport coefficients are derivable. We find significant statistical improvement over traditional Green-Kubo based calculations. The systematic and statistical errors of this method are analyzed in the context of specific transport coefficient calculations, including the shear viscosity, interfacial friction coefficient, and thermal conductivity.

Power coefficient anomaly in JOYO

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, H

1980-12-15

Operation of the JOYO experimental fast reactor with the MK-I core has been divided into two phases: (1) 50 MWt power ascension and operation; and (2) 75 MWt power ascension and operation. The 50 MWt power-up tests were conducted in August 1978. In these tests, the measured reactivity loss due to power increases from 15 MWt to 50 MWt was 0.28% ..delta.. K/K, and agreed well with the predicted value of 0.27% ..delta.. K/K. The 75 MWt power ascension tests were conducted in July-August 1979. In the process of the first power increase above 50 MWt to 65 MWt conducted on July 11, 1979, an anomalously large negative power coefficient was observed. The value was about twice the power coefficient values measured in the tests below 50 MW. In order to reproduce the anomaly, the reactor power was decreased and again increased up to the maximum power of 65 MWt. However, the large negative power coefficient was not observed at this time. In the succeeding power increase from 65 MWt to 75 MWt, a similar anomalous power coefficient was again observed. This anomaly disappeared in the subsequent power ascensions to 75 MWt, and the magnitude of the power coefficient gradually decreased with power cycles above the 50 MWt level.

Perceptual learning effect on decision and confidence thresholds.

Science.gov (United States)

Solovey, Guillermo; Shalom, Diego; Pérez-Schuster, Verónica; Sigman, Mariano

2016-10-01

Practice can enhance of perceptual sensitivity, a well-known phenomenon called perceptual learning. However, the effect of practice on subjective perception has received little attention. We approach this problem from a visual psychophysics and computational modeling perspective. In a sequence of visual search experiments, subjects significantly increased the ability to detect a "trained target". Before and after training, subjects performed two psychophysical protocols that parametrically vary the visibility of the "trained target": an attentional blink and a visual masking task. We found that confidence increased after learning only in the attentional blink task. Despite large differences in some observables and task settings, we identify common mechanisms for decision-making and confidence. Specifically, our behavioral results and computational model suggest that perceptual ability is independent of processing time, indicating that changes in early cortical representations are effective, and learning changes decision criteria to convey choice and confidence. Copyright © 2016 Elsevier Inc. All rights reserved.

Summary of the activities of the ISAM Confidence Building Working Group

International Nuclear Information System (INIS)

Dolinar, G.M.; Batandjieva, B.

2002-01-01

During the early stages of the ISAM project confidence building was a relatively new topic in the radioactive waste disposal literature, but it was beginning to receive some attention. Although almost all safety assessment activities are intended to provide a level of confidence in the results of the assessment, considering the activities from the viewpoint of how they contributed to the decision making of various 'audiences' was relatively new. The ISAM project included the Confidence Building Working Group (CBWG) to examine the topic of Confidence Building and this paper provides a summary of the working group findings. (author)

Kangaroo Care Education Effects on Nurses' Knowledge and Skills Confidence.

Science.gov (United States)

Almutairi, Wedad Matar; Ludington-Hoe, Susan M

2016-11-01

Less than 20% of the 996 NICUs in the United States routinely practice kangaroo care, due in part to the inadequate knowledge and skills confidence of nurses. Continuing education improves knowledge and skills acquisition, but the effects of a kangaroo care certification course on nurses' knowledge and skills confidence are unknown. A pretest-posttest quasi-experiment was conducted. The Kangaroo Care Knowledge and Skills Confidence Tool was administered to 68 RNs at a 2.5-day course about kangaroo care evidence and skills. Measures of central tendency, dispersion, and paired t tests were conducted on 57 questionnaires. The nurses' characteristics were varied. The mean posttest Knowledge score (M = 88.54, SD = 6.13) was significantly higher than the pretest score (M = 78.7, SD = 8.30), t [54] = -9.1, p = .000), as was the posttest Skills Confidence score (pretest M = 32.06, SD = 3.49; posttest M = 26.80, SD = 5.22), t [53] = -8.459, p = .000). The nurses' knowledge and skills confidence of kangaroo care improved following continuing education, suggesting a need for continuing education in this area. J Contin Educ Nurs. 2016;47(11):518-524. Copyright 2016, SLACK Incorporated.

Confidence intervals for experiments with background and small numbers of events

International Nuclear Information System (INIS)

Bruechle, W.

2003-01-01

Methods to find a confidence interval for Poisson distributed variables are illuminated, especially for the case of poor statistics. The application of 'central' and 'highest probability density' confidence intervals is compared for the case of low count-rates. A method to determine realistic estimates of the confidence intervals for Poisson distributed variables affected with background, and their ratios, is given. (orig.)

Confidence intervals for experiments with background and small numbers of events

International Nuclear Information System (INIS)

Bruechle, W.

2002-07-01

Methods to find a confidence interval for Poisson distributed variables are illuminated, especially for the case of poor statistics. The application of 'central' and 'highest probability density' confidence intervals is compared for the case of low count-rates. A method to determine realistic estimates of the confidence intervals for Poisson distributed variables affected with background, and their ratios, is given. (orig.)

Temperature dependence of Kerr coefficient and quadratic polarized optical coefficient of a paraelectric Mn:Fe:KTN crystal

Directory of Open Access Journals (Sweden)

Qieni Lu

2015-08-01

Full Text Available We measure temperature dependence on Kerr coefficient and quadratic polarized optical coefficient of a paraelectric Mn:Fe:KTN crystal simultaneously in this work, based on digital holographic interferometry (DHI. And the spatial distribution of the field-induced refractive index change can also be visualized and estimated by numerically retrieving sequential phase maps of Mn:Fe:KTN crystal from recording digital holograms in different states. The refractive indices decrease with increasing temperature and quadratic polarized optical coefficient is insensitive to temperature. The experimental results suggest that the DHI method presented here is highly applicable in both visualizing the temporal and spatial behavior of the internal electric field and accurately measuring electro-optic coefficient for electrooptical media.

Three-dimensional transport coefficient model and prediction-correction numerical method for thermal margin analysis of PWR cores

International Nuclear Information System (INIS)

Chiu, C.

1981-01-01

Combustion Engineering Inc. designs its modern PWR reactor cores using open-core thermal-hydraulic methods where the mass, momentum and energy equations are solved in three dimensions (one axial and two lateral directions). The resultant fluid properties are used to compute the minimum Departure from Nuclear Boiling Ratio (DNBR) which ultimately sets the power capability of the core. The on-line digital monitoring and protection systems require a small fast-running algorithm of the design code. This paper presents two techniques used in the development of the on-line DNB algorithm. First, a three-dimensional transport coefficient model is introduced to radially group the flow subchannel into channels for the thermal-hydraulic fluid properties calculation. Conservation equations of mass, momentum and energy for this channels are derived using transport coefficients to modify the calculation of the radial transport of enthalpy and momentum. Second, a simplified, non-iterative numerical method, called the prediction-correction method, is applied together with the transport coefficient model to reduce the computer execution time in the determination of fluid properties. Comparison of the algorithm and the design thermal-hydraulic code shows agreement to within 0.65% equivalent power at a 95/95 confidence/probability level for all normal operating conditions of the PWR core. This algorithm accuracy is achieved with 1/800th of the computer processing time of its parent design code. (orig.)

Colorectal liver metastases: contrast agent diffusion coefficient for quantification of contrast enhancement heterogeneity at MR imaging.

Science.gov (United States)

Jia, Guang; O'Dell, Craig; Heverhagen, Johannes T; Yang, Xiangyu; Liang, Jiachao; Jacko, Richard V; Sammet, Steffen; Pellas, Theodore; Cole, Patricia; Knopp, Michael V

2008-09-01

To describe and determine the reproducibility of a simplified model to quantitatively measure heterogeneous intralesion contrast agent diffusion in colorectal liver metastases. This HIPAA-compliant retrospective study received institutional review board approval, and written informed consent was obtained from 14 patients (mean age, 61 years +/- 9 [standard deviation]; range, 41-78 years), including 10 men (mean age, 65 years +/- 8; range, 47-78 years) and four women (mean age, 54 years +/- 9; range, 41-59 years), with colorectal liver metastases. Magnetic resonance (MR) imaging was performed twice (first baseline MR image [B(1)] and second baseline MR image [B(2)]) in a single target lesion prior to therapy. Dynamic contrast material-enhanced MR imaging was performed by using a saturation-recovery fast gradient-echo sequence. A simplified contrast agent diffusion model was proposed, and a contrast agent diffusion coefficient (CDC) was calculated. The reproducibility of the CDC measurement was evaluated by using the Bland-Altman plot and a linear regression model. The mean CDC was 0.22 mm(2)/sec (range, 0.01-0.73 mm(2)/sec) on B(1) and 0.24 mm(2)/sec (range, 0.01-0.71 mm(2)/sec) on B(2), with an intraclass correlation coefficient of 0.91 (P < .0001). Bland-Altman plot showed good agreement, with a mean difference in measurement pairs of 0.017 mm(2)/sec +/- 0.096. The slope from the linear regression model was 0.89 (95% confidence interval: 0.63, 1.15) and the intercept was 0.01 (95% confidence interval: -0.08, 0.09). The CDC enables a quantitative description of contrast enhancement heterogeneity in lesions. Given the high reproducibility of the CDC metric, CDC appears promising for further qualification as an imaging biomarker of change measurement in response assessment. http://radiology.rsnajnls.org/cgi/content/full/248/3/901/DC1. RSNA, 2008

Form coefficient of helical toroidal solenoids

International Nuclear Information System (INIS)

Amelin, V.Z.; Kunchenko, V.B.

1982-01-01

For toroidal solenoids with continuous spiral coil, winded according to the laws of equiinclined and simple cylindrical spirals with homogeneous, linearly increasing to the coil periphery and ''Bitter'' distribution of current density, the analytical expressions for the dependence between capacity consumed and generated magnetic field, expressions for coefficients of form similar to Fabry coefficient for cylindrical solenoids are obtained and dependence of the form coefficient and relative volume of solenoid conductor on the number of revolutions of screw line per one circumvention over the large torus radius is also investigated. Analytical expressions of form coefficients and graphical material permit to select the optimum geometry as to capacity consumed both for spiral (including ''force-free'') and conventional toroidal solenoids of magnetic systems in thermonulear installations

Friction coefficient dependence on electrostatic tribocharging.

Science.gov (United States)

Burgo, Thiago A L; Silva, Cristiane A; Balestrin, Lia B S; Galembeck, Fernando

2013-01-01

Friction between dielectric surfaces produces patterns of fixed, stable electric charges that in turn contribute electrostatic components to surface interactions between the contacting solids. The literature presents a wealth of information on the electronic contributions to friction in metals and semiconductors but the effect of triboelectricity on friction coefficients of dielectrics is as yet poorly defined and understood. In this work, friction coefficients were measured on tribocharged polytetrafluoroethylene (PTFE), using three different techniques. As a result, friction coefficients at the macro- and nanoscales increase many-fold when PTFE surfaces are tribocharged, but this effect is eliminated by silanization of glass spheres rolling on PTFE. In conclusion, tribocharging may supersede all other contributions to macro- and nanoscale friction coefficients in PTFE and probably in other insulating polymers.

Effects of parental divorce on marital commitment and confidence.

Science.gov (United States)

Whitton, Sarah W; Rhoades, Galena K; Stanley, Scott M; Markman, Howard J

2008-10-01

Research on the intergenerational transmission of divorce has demonstrated that compared with offspring of nondivorced parents, those of divorced parents generally have more negative attitudes toward marriage as an institution and are less optimistic about the feasibility of a long-lasting, healthy marriage. It is also possible that when entering marriage themselves, adults whose parents divorced have less personal relationship commitment to their own marriages and less confidence in their own ability to maintain a happy marriage with their spouse. However, this prediction has not been tested. In the current study, we assessed relationship commitment and relationship confidence, as well as parental divorce and retrospectively reported interparental conflict, in a sample of 265 engaged couples prior to their first marriage. Results demonstrated that women's, but not men's, parental divorce was associated with lower relationship commitment and lower relationship confidence. These effects persisted when controlling for the influence of recalled interparental conflict and premarital relationship adjustment. The current findings suggest that women whose parents divorced are more likely to enter marriage with relatively lower commitment to, and confidence in, the future of those marriages, potentially raising their risk for divorce. Copyright 2008 APA, all rights reserved.

The effect of terrorism on public confidence : an exploratory study.

Energy Technology Data Exchange (ETDEWEB)

Berry, M. S.; Baldwin, T. E.; Samsa, M. E.; Ramaprasad, A.; Decision and Information Sciences

2008-10-31

A primary goal of terrorism is to instill a sense of fear and vulnerability in a population and to erode confidence in government and law enforcement agencies to protect citizens against future attacks. In recognition of its importance, the Department of Homeland Security includes public confidence as one of the metrics it uses to assess the consequences of terrorist attacks. Hence, several factors--including a detailed understanding of the variations in public confidence among individuals, by type of terrorist event, and as a function of time--are critical to developing this metric. In this exploratory study, a questionnaire was designed, tested, and administered to small groups of individuals to measure public confidence in the ability of federal, state, and local governments and their public safety agencies to prevent acts of terrorism. Data were collected from the groups before and after they watched mock television news broadcasts portraying a smallpox attack, a series of suicide bomber attacks, a refinery bombing, and cyber intrusions on financial institutions that resulted in identity theft and financial losses. Our findings include the following: (a) the subjects can be classified into at least three distinct groups on the basis of their baseline outlook--optimistic, pessimistic, and unaffected; (b) the subjects make discriminations in their interpretations of an event on the basis of the nature of a terrorist attack, the time horizon, and its impact; (c) the recovery of confidence after a terrorist event has an incubation period and typically does not return to its initial level in the long-term; (d) the patterns of recovery of confidence differ between the optimists and the pessimists; and (e) individuals are able to associate a monetary value with a loss or gain in confidence, and the value associated with a loss is greater than the value associated with a gain. These findings illustrate the importance the public places in their confidence in government

Friction coefficient dependence on electrostatic tribocharging

Science.gov (United States)

Burgo, Thiago A. L.; Silva, Cristiane A.; Balestrin, Lia B. S.; Galembeck, Fernando

2013-01-01

Friction between dielectric surfaces produces patterns of fixed, stable electric charges that in turn contribute electrostatic components to surface interactions between the contacting solids. The literature presents a wealth of information on the electronic contributions to friction in metals and semiconductors but the effect of triboelectricity on friction coefficients of dielectrics is as yet poorly defined and understood. In this work, friction coefficients were measured on tribocharged polytetrafluoroethylene (PTFE), using three different techniques. As a result, friction coefficients at the macro- and nanoscales increase many-fold when PTFE surfaces are tribocharged, but this effect is eliminated by silanization of glass spheres rolling on PTFE. In conclusion, tribocharging may supersede all other contributions to macro- and nanoscale friction coefficients in PTFE and probably in other insulating polymers. PMID:23934227

An Exact Confidence Region in Multivariate Calibration

OpenAIRE

Mathew, Thomas; Kasala, Subramanyam

1994-01-01

In the multivariate calibration problem using a multivariate linear model, an exact confidence region is constructed. It is shown that the region is always nonempty and is invariant under nonsingular transformations.

A Poisson process approximation for generalized K-5 confidence regions

Science.gov (United States)

Arsham, H.; Miller, D. R.

1982-01-01

One-sided confidence regions for continuous cumulative distribution functions are constructed using empirical cumulative distribution functions and the generalized Kolmogorov-Smirnov distance. The band width of such regions becomes narrower in the right or left tail of the distribution. To avoid tedious computation of confidence levels and critical values, an approximation based on the Poisson process is introduced. This aproximation provides a conservative confidence region; moreover, the approximation error decreases monotonically to 0 as sample size increases. Critical values necessary for implementation are given. Applications are made to the areas of risk analysis, investment modeling, reliability assessment, and analysis of fault tolerant systems.

Institutional Confidence in the United States: Attitudes of Secular Americans

Directory of Open Access Journals (Sweden)

Isabella Kasselstrand

2017-04-01

Full Text Available The First Amendment to the United States’ Constitution addresses freedom of religion and the separation of church and state. However, the historical influence of religion in laws, policies, and political representation have left secular individuals feeling excluded. At the same time, levels of confidence in social and political institutions in the United States are at an all-time low. This begs the question: Is there a relationship between secularity and confidence in various social and political institutions (e.g. the armed forces, churches, major companies, government, police, and political parties? This question is examined using data on the United States from the World Values Survey from 1995–2011. While controlling for a range of key demographics, the findings show a negative relationship between secularity and institutional confidence. More specifically, atheists and nonreligious individuals are less likely than those who are religious to have confidence in all six institutions. Based on previous literature and the empirical evidence presented in this study, we argue that overall lower levels of institutional confidence among secular Americans is an outcome of the exclusion of such individuals from American social life. Thus, it highlights the importance of addressing the stereotypes and prejudice that this minority group faces.

Calculation of transport coefficients in an axisymmetric plasma

International Nuclear Information System (INIS)

Shumaker, D.E.

1976-01-01

A method of calculating the transport coefficient in an axisymmetric toroidal plasma is presented. This method is useful in calculating the transport coefficients in a Tokamak plasma confinement device. The particle density and temperature are shown to be a constant on a magnetic flux surface. Transport equations are given for the total particle flux and total energy flux crossing a closed toroidal surface. Also transport equations are given for the toroidal magnetic flux. A computer code was written to calculate the transport coefficients for a three species plasma, electrons and two species of ions. This is useful for calculating the transport coefficients of a plasma which contains impurities. It was found that the particle and energy transport coefficients are increased by a large amount, and the transport coefficients for the toroidal magnetic field are reduced by a small amount. For example, a deuterium plasma with 1.3 percent oxygen, one of the particle transport coefficients is increased by a factor of about four. The transport coefficients for the toroidal magnetic flux are reduced by about 20 percent. The increase in the particle transport coefficient is due to the collisional scattering of the deuterons by the heavy oxygen ions which is larger than the deuteron electron scattering, the normal process for particle transport in a two species plasma. The reduction in the toroidal magnetic flux transport coefficients are left unexplained

Teachers and Counselors: Building Math Confidence in Schools

Directory of Open Access Journals (Sweden)

Joseph M. Furner

2017-08-01

Full Text Available Mathematics teachers need to take on the role of counselors in addressing the math anxious in today's math classrooms. This paper looks at the impact math anxiety has on the future of young adults in our high-tech society. Teachers and professional school counselors are encouraged to work together to prevent and reduce math anxiety. It is important that all students feel confident in their ability to do mathematics in an age that relies so heavily on problem solving, technology, science, and mathematics. It really is a school's obligation to see that their students value and feel confident in their ability to do math, because ultimately a child's life: all decisions they will make and careers choices may be determined based on their disposition toward mathematics. This paper raises some interesting questions and provides some strategies (See Appendix A for teachers and counselors for addressing the issue of math anxiety while discussing the importance of developing mathematically confident young people for a high-tech world of STEM.

Building public confidence in the world's nuclear industry

International Nuclear Information System (INIS)

Duncan, C.D.

1996-01-01

Public confidence in the nuclear industry requires two things, which are trust and understanding. Trust is an emotional response based upon an instinctive reaction. Understanding, on the other hand, is an intellectual response based upon facts. To gain public confidence, both of these levels must be communicated and proactive strategies must be implemented to do this. To achieve this objective will require confidence and courage in communication programs. Each company operating in the nuclear sector must be proactive in building its individual reputation and must not retreat from controversy. Similarly, each industry body must continue the Herculean task of building understanding. The nuclear industry has powerful arguments. ICI, BP or Ford did not achieve their licences to operate by keeping their heads down, they achieved their current market positions by building a positive corporate reputation within their respective industrial contexts over many decades. In order to achieve a similar position for the nuclear industry and the companies, their examples must be followed. If it is continued to 'keep the heads down' in the trenches, public opinion will surely bury within it. (G.K.)

Transfer coefficients in ultracold strongly coupled plasma

Science.gov (United States)

Bobrov, A. A.; Vorob'ev, V. S.; Zelener, B. V.

2018-03-01

We use both analytical and molecular dynamic methods for electron transfer coefficients in an ultracold plasma when its temperature is small and the coupling parameter characterizing the interaction of electrons and ions exceeds unity. For these conditions, we use the approach of nearest neighbor to determine the average electron (ion) diffusion coefficient and to calculate other electron transfer coefficients (viscosity and electrical and thermal conductivities). Molecular dynamics simulations produce electronic and ionic diffusion coefficients, confirming the reliability of these results. The results compare favorably with experimental and numerical data from earlier studies.

Two sides of the same coin: Monetary incentives concurrently improve and bias confidence judgments.

Science.gov (United States)

Lebreton, Maël; Langdon, Shari; Slieker, Matthijs J; Nooitgedacht, Jip S; Goudriaan, Anna E; Denys, Damiaan; van Holst, Ruth J; Luigjes, Judy

2018-05-01

Decisions are accompanied by a feeling of confidence, that is, a belief about the decision being correct. Confidence accuracy is critical, notably in high-stakes situations such as medical or financial decision-making. We investigated how incentive motivation influences confidence accuracy by combining a perceptual task with a confidence incentivization mechanism. By varying the magnitude and valence (gains or losses) of monetary incentives, we orthogonalized their motivational and affective components. Corroborating theories of rational decision-making and motivation, our results first reveal that the motivational value of incentives improves aspects of confidence accuracy. However, in line with a value-confidence interaction hypothesis, we further show that the affective value of incentives concurrently biases confidence reports, thus degrading confidence accuracy. Finally, we demonstrate that the motivational and affective effects of incentives differentially affect how confidence builds on perceptual evidence. Together, these findings may provide new hints about confidence miscalibration in healthy or pathological contexts.

Two sides of the same coin: Monetary incentives concurrently improve and bias confidence judgments

Science.gov (United States)

Lebreton, Maël; Slieker, Matthijs J.; Nooitgedacht, Jip S.; van Holst, Ruth J.; Luigjes, Judy

2018-01-01

Decisions are accompanied by a feeling of confidence, that is, a belief about the decision being correct. Confidence accuracy is critical, notably in high-stakes situations such as medical or financial decision-making. We investigated how incentive motivation influences confidence accuracy by combining a perceptual task with a confidence incentivization mechanism. By varying the magnitude and valence (gains or losses) of monetary incentives, we orthogonalized their motivational and affective components. Corroborating theories of rational decision-making and motivation, our results first reveal that the motivational value of incentives improves aspects of confidence accuracy. However, in line with a value-confidence interaction hypothesis, we further show that the affective value of incentives concurrently biases confidence reports, thus degrading confidence accuracy. Finally, we demonstrate that the motivational and affective effects of incentives differentially affect how confidence builds on perceptual evidence. Together, these findings may provide new hints about confidence miscalibration in healthy or pathological contexts. PMID:29854944

Growing confidence, building skills | IDRC - International ...

International Development Research Centre (IDRC) Digital Library (Canada)

In 2012 Rashid explored the influence of think tanks on policy in Bangladesh, as well as their relationships with international donors and media. In 2014, he explored two-way student exchanges between Canadian and ... his IDRC experience “gave me the confidence to conduct high quality research in social sciences.”.

Radionuclides distribution coefficient of soil to soil-solution

International Nuclear Information System (INIS)

1990-06-01

The present book addresses various issues related with the coefficient of radionuclides distribution between soil and soil solution. It consists of six sections and two appendices. The second section, following an introductory one, describes the definition of the coefficient and a procedures of its calculation. The third section deals with the application of the distribution coefficient to the prediction of movements of radionuclides through soil. Various methods for measuring the coefficient are described in the fourth section. The next section discusses a variety of factors (physical and chemical) that can affect the distribution coefficient. Measurements of the coefficient for different types of oils are listed in the sixth section. An appendix is attached to the book to show various models that can be helpful in applying the coefficient of distribution of radionuclides moving from soil into agricultural plants. (N.K.)

Soccer Ball Lift Coefficients via Trajectory Analysis

Science.gov (United States)

Goff, John Eric; Carre, Matt J.

2010-01-01

We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin…

A scale for consumer confidence in the safety of food

NARCIS (Netherlands)

Jonge, de J.; Trijp, van J.C.M.; Lans, van der I.A.; Renes, R.J.; Frewer, L.J.

2008-01-01

The aim of this study was to develop and validate a scale to measure general consumer confidence in the safety of food. Results from exploratory and confirmatory analyses indicate that general consumer confidence in the safety of food consists of two distinct dimensions, optimism and pessimism,

Confidence Scoring of Speaking Performance: How Does Fuzziness become Exact?

Science.gov (United States)

Jin, Tan; Mak, Barley; Zhou, Pei

2012-01-01

The fuzziness of assessing second language speaking performance raises two difficulties in scoring speaking performance: "indistinction between adjacent levels" and "overlap between scales". To address these two problems, this article proposes a new approach, "confidence scoring", to deal with such fuzziness, leading to "confidence" scores between…

Variance misperception explains illusions of confidence in simple perceptual decisions

NARCIS (Netherlands)

Zylberberg, Ariel; Roelfsema, Pieter R.; Sigman, Mariano

2014-01-01

Confidence in a perceptual decision is a judgment about the quality of the sensory evidence. The quality of the evidence depends not only on its strength ('signal') but critically on its reliability ('noise'), but the separate contribution of these quantities to the formation of confidence judgments

Assessing confidence in management adaptation approaches for climate-sensitive ecosystems

International Nuclear Information System (INIS)

West, J M; Julius, S H; Weaver, C P

2012-01-01

A number of options are available for adapting ecosystem management to improve resilience in the face of climatic changes. However, uncertainty exists as to the effectiveness of these options. A report prepared for the US Climate Change Science Program reviewed adaptation options for a range of federally managed systems in the United States. The report included a qualitative uncertainty analysis of conceptual approaches to adaptation derived from the review. The approaches included reducing anthropogenic stressors, protecting key ecosystem features, maintaining representation, replicating, restoring, identifying refugia and relocating organisms. The results showed that the expert teams had the greatest scientific confidence in adaptation options that reduce anthropogenic stresses. Confidence in other approaches was lower because of gaps in understanding of ecosystem function, climate change impacts on ecosystems, and management effectiveness. This letter discusses insights gained from the confidence exercise and proposes strategies for improving future assessments of confidence for management adaptations to climate change. (letter)

THE USE OF SKIT TECHNIQUE TO INCREASE STUDENTS’ SELF-CONFIDENCE IN SPEAKING

Directory of Open Access Journals (Sweden)

Dini Deswarni

2017-12-01

The study aimed to know the use of Skit Technique to increase students’ self-confidence in speaking English. Speaking is one of important skills in English. Self-Confidence is really need to speak in English. Someone needs self-confidence to express their idea and their feelings in a foreign language especially in English. Not all of the people have good self-confidence in using English to express or to share their idea and their opinion. The aim of this study is to know whether the Skit Technique can increase self- confidence in speaking English. In other words Skit Technique can help to increase self-confidence in speaking English. The design of this research is experiment. The population of the research is 46 students at the eight grade students of MTs Darul Ihsan Duri. The sample technique is random sampling. From the data, it can be seen that Ttable < Tvalue (2.101 < 12.466. It means Ha is accepted and Skit Technique done in experiment class.

Monitoring device for local power peaking coefficients

International Nuclear Information System (INIS)

Mihashi, Ishi

1987-01-01

Purpose: To determine and monitor the local power peaking coefficients by a method not depending on the combination of fuel types. Constitution: Representative values for the local power distribution can be obtained by determining corresponding burn-up degrees based on the burn-up degree of each of fuel assembly segments obtained in a power distribution monitor and by the interpolation and extrapolation of void coefficients. The typical values are multiplied with compensation coefficients for the control rod effect and coefficients for compensating the effect of adjacent fuel assemblies in a calculation device to obtain typical values for the present local power distribution compensated with all of the effects. Further, the calculation device compares them with typical values of the present local power distribution to obtain an aimed local power peaking coefficient as the maximum value thereof. According to the present invention, since the local power peaking coefficients can be determined not depending on the combination of the kind of fuels, if the combination of fuel assemblies is increased upon fuel change, the amount of operation therefor is not increased. (Kamimura, M.)

Monitoring device for local power peaking coefficient

International Nuclear Information System (INIS)

Mitsuhashi, Ishi

1987-01-01

Purpose: To monitor the local power peaking coefficients obtained by the method not depending on the combination of fuel types. Method: A plurality of representative values for the local power distribution determined by the nuclear constant calculation for one fuel assembly are memorized regarding each of the burn-up degree and the void coefficient on every positions and fuel types in fuel rod assemblies. While on the other hand, the representative values for the local power distribution as described above are compensated by a compensation coefficient considering the effect of adjacent segments and a control rod compensation coefficient considering the effect due to the control rod insertion relative to the just-mentioned compensation coefficient. Then, the maximum value among them is selected to determine the local power peaking coefficient at each of the times and each of the segments, which is monitored. According to this system, the calculation and the working required for the fitting work depending on the combination of fuel types are no more required at all to facilitate the maintenance as well. (Horiuchi, T.)

Using an R Shiny to Enhance the Learning Experience of Confidence Intervals

Science.gov (United States)

Williams, Immanuel James; Williams, Kelley Kim

2018-01-01

Many students find understanding confidence intervals difficult, especially because of the amalgamation of concepts such as confidence levels, standard error, point estimates and sample sizes. An R Shiny application was created to assist the learning process of confidence intervals using graphics and data from the US National Basketball…

Properties of Traffic Risk Coefficient

Science.gov (United States)

Tang, Tie-Qiao; Huang, Hai-Jun; Shang, Hua-Yan; Xue, Yu

2009-10-01

We use the model with the consideration of the traffic interruption probability (Physica A 387(2008)6845) to study the relationship between the traffic risk coefficient and the traffic interruption probability. The analytical and numerical results show that the traffic interruption probability will reduce the traffic risk coefficient and that the reduction is related to the density, which shows that this model can improve traffic security.

Development and Evaluation of a Confidence-Weighting Computerized Adaptive Testing

Science.gov (United States)

Yen, Yung-Chin; Ho, Rong-Guey; Chen, Li-Ju; Chou, Kun-Yi; Chen, Yan-Lin

2010-01-01

The purpose of this study was to examine whether the efficiency, precision, and validity of computerized adaptive testing (CAT) could be improved by assessing confidence differences in knowledge that examinees possessed. We proposed a novel polytomous CAT model called the confidence-weighting computerized adaptive testing (CWCAT), which combined a…

Confident Communication: Speaking Tips for Educators.

Science.gov (United States)

Parker, Douglas A.

This resource book seeks to provide the building blocks needed for public speaking while eliminating the fear factor. The book explains how educators can perfect their oratorical capabilities as well as enjoy the security, confidence, and support needed to create and deliver dynamic speeches. Following an Introduction: A Message for Teachers,…

Confidence intervals for correlations when data are not normal.

Science.gov (United States)

Bishara, Anthony J; Hittner, James B

2017-02-01

With nonnormal data, the typical confidence interval of the correlation (Fisher z') may be inaccurate. The literature has been unclear as to which of several alternative methods should be used instead, and how extreme a violation of normality is needed to justify an alternative. Through Monte Carlo simulation, 11 confidence interval methods were compared, including Fisher z', two Spearman rank-order methods, the Box-Cox transformation, rank-based inverse normal (RIN) transformation, and various bootstrap methods. Nonnormality often distorted the Fisher z' confidence interval-for example, leading to a 95 % confidence interval that had actual coverage as low as 68 %. Increasing the sample size sometimes worsened this problem. Inaccurate Fisher z' intervals could be predicted by a sample kurtosis of at least 2, an absolute sample skewness of at least 1, or significant violations of normality hypothesis tests. Only the Spearman rank-order and RIN transformation methods were universally robust to nonnormality. Among the bootstrap methods, an observed imposed bootstrap came closest to accurate coverage, though it often resulted in an overly long interval. The results suggest that sample nonnormality can justify avoidance of the Fisher z' interval in favor of a more robust alternative. R code for the relevant methods is provided in supplementary materials.

Prediction of friction coefficients for gases

Science.gov (United States)

Taylor, M. F.

1969-01-01

Empirical relations are used for correlating laminar and turbulent friction coefficients for gases, with large variations in the physical properties, flowing through smooth tubes. These relations have been used to correlate friction coefficients for hydrogen, helium, nitrogen, carbon dioxide and air.

Computing exact Fourier series coefficients of IC rectilinear polygons from low-resolution fast Fourier coefficients

Science.gov (United States)

Scheibler, Robin; Hurley, Paul

2012-03-01

We present a novel, accurate and fast algorithm to obtain Fourier series coefficients from an IC layer whose description consists of rectilinear polygons on a plane, and how to implement it using off-the-shelf hardware components. Based on properties of Fourier calculus, we derive a relationship between the Discrete Fourier Transforms of the sampled mask transmission function and its continuous Fourier series coefficients. The relationship leads to a straightforward algorithm for computing the continuous Fourier series coefficients where one samples the mask transmission function, compute its discrete Fourier transform and applies a frequency-dependent multiplicative factor. The algorithm is guaranteed to yield the exact continuous Fourier series coefficients for any sampling representing the mask function exactly. Computationally, this leads to significant saving by allowing to choose the maximal such pixel size and reducing the fast Fourier transform size by as much, without compromising accuracy. In addition, the continuous Fourier series is free from aliasing and follows closely the physical model of Fourier optics. We show that in some cases this can make a significant difference, especially in modern very low pitch technology nodes.

Comparing linear probability model coefficients across groups

DEFF Research Database (Denmark)

Holm, Anders; Ejrnæs, Mette; Karlson, Kristian Bernt

2015-01-01

of the following three components: outcome truncation, scale parameters and distributional shape of the predictor variable. These results point to limitations in using linear probability model coefficients for group comparisons. We also provide Monte Carlo simulations and real examples to illustrate......This article offers a formal identification analysis of the problem in comparing coefficients from linear probability models between groups. We show that differences in coefficients from these models can result not only from genuine differences in effects, but also from differences in one or more...... these limitations, and we suggest a restricted approach to using linear probability model coefficients in group comparisons....

Diffusion coefficient of three-dimensional Yukawa liquids

International Nuclear Information System (INIS)

Dzhumagulova, K. N.; Ramazanov, T. S.; Masheeva, R. U.

2013-01-01

The purpose of this work is an investigation of the diffusion coefficient of the dust component in complex plasma. The computer simulation of the Yukawa liquids was made on the basis of the Langevin equation, which takes into account the influence of buffer plasma on the dust particles dynamics. The Green–Kubo relation was used to calculate the diffusion coefficient. Calculations of the diffusion coefficient for a wide range of the system parameters were performed. Using obtained numerical data, we constructed the interpolation formula for the diffusion coefficient. We also show that the interpolation formula correctly describes experimental data obtained under microgravity conditions

The application of deep confidence network in the problem of image recognition

Directory of Open Access Journals (Sweden)

Chumachenko О.І.

2016-12-01

Full Text Available In order to study the concept of deep learning, in particular the substitution of multilayer perceptron on the corresponding network of deep confidence, computer simulations of the learning process to test voters was carried out. Multi-layer perceptron has been replaced by a network of deep confidence, consisting of successive limited Boltzmann machines. After training of a network of deep confidence algorithm of layer-wise training it was found that the use of networks of deep confidence greatly improves the accuracy of multilayer perceptron training by method of reverse distribution errors.

Diffusion coefficients of paracetamol in aqueous solutions

International Nuclear Information System (INIS)

Ribeiro, Ana C.F.; Barros, Marisa C.F.; Veríssimo, Luís M.P.; Santos, Cecilia I.A.V.; Cabral, Ana M.T.D.P.V.; Gaspar, Gualter D.; Esteso, Miguel A.

2012-01-01

Highlights: ► Mutual diffusion coefficients of paracetamol in aqueous dilute solutions. ► Influence of the thermodynamic factors on the variation of their mutual diffusion coefficients. ► Estimation of the mutual limiting diffusion coefficients of the molecular, D m 0 , and ionized forms, D ± 0 , of this drug. - Abstract: Binary mutual diffusion coefficients measured by the Taylor dispersion method, for aqueous solutions of paracetamol (PA) at concentrations from (0.001 to 0.050) mol·dm −3 at T = 298.15 K, are reported. From the Nernst–Hartley equation and our experimental results, the limiting diffusion coefficient of this drug and its thermodynamic factors are estimated, thereby contributing in this way to a better understanding of the structure of such systems and of their thermodynamic behaviour in aqueous solution at different concentrations.

The accuracy of meta-metacognitive judgments: regulating the realism of confidence.

Science.gov (United States)

Buratti, Sandra; Allwood, Carl Martin

2012-08-01

Can people improve the realism of their confidence judgments about the correctness of their episodic memory reports by deselecting the least realistic judgments? An assumption of Koriat and Goldsmith's (Psychol Rev 103:490-517, 1996) model is that confidence judgments regulate the reporting of memory reports. We tested whether this assumption generalizes to the regulation of the realism (accuracy) of confidence judgments. In two experiments, 270 adults in separate conditions answered 50 recognition and recall questions about the contents of a just-seen video. After each answer, they made confidence judgments about the answer's correctness. In Experiment 1, the participants in the recognition conditions significantly increased their absolute bias when they excluded 15 questions. In Experiment 2, the participants in the recall condition significantly improved their calibration. The results indicate that recall, more than recognition, offers valid cues for participants to increase the realism of their report. However, the effects were small with only weak support for the conclusion that people have some ability to regulate the realism in their confidence judgments.

Emotor control: computations underlying bodily resource allocation, emotions, and confidence.

Science.gov (United States)

Kepecs, Adam; Mensh, Brett D

2015-12-01

Emotional processes are central to behavior, yet their deeply subjective nature has been a challenge for neuroscientific study as well as for psychiatric diagnosis. Here we explore the relationships between subjective feelings and their underlying brain circuits from a computational perspective. We apply recent insights from systems neuroscience-approaching subjective behavior as the result of mental computations instantiated in the brain-to the study of emotions. We develop the hypothesis that emotions are the product of neural computations whose motor role is to reallocate bodily resources mostly gated by smooth muscles. This "emotor" control system is analagous to the more familiar motor control computations that coordinate skeletal muscle movements. To illustrate this framework, we review recent research on "confidence." Although familiar as a feeling, confidence is also an objective statistical quantity: an estimate of the probability that a hypothesis is correct. This model-based approach helped reveal the neural basis of decision confidence in mammals and provides a bridge to the subjective feeling of confidence in humans. These results have important implications for psychiatry, since disorders of confidence computations appear to contribute to a number of psychopathologies. More broadly, this computational approach to emotions resonates with the emerging view that psychiatric nosology may be best parameterized in terms of disorders of the cognitive computations underlying complex behavior.

Approximate reflection coefficients for a thin VTI layer

KAUST Repository

Hao, Qi

2017-09-18

We present an approximate method to derive simple expressions for the reflection coefficients of P- and SV-waves for a thin transversely isotropic layer with a vertical symmetry axis (VTI) embedded in a homogeneous VTI background. The layer thickness is assumed to be much smaller than the wavelengths of P- and SV-waves inside. The exact reflection and transmission coefficients are derived by the propagator matrix method. In the case of normal incidence, the exact reflection and transmission coefficients are expressed in terms of the impedances of vertically propagating P- and S-waves. For subcritical incidence, the approximate reflection coefficients are expressed in terms of the contrast in the VTI parameters between the layer and the background. Numerical examples are designed to analyze the reflection coefficients at normal and oblique incidence, and investigate the influence of transverse isotropy on the reflection coefficients. Despite giving numerical errors, the approximate formulae are sufficiently simple to qualitatively analyze the variation of the reflection coefficients with the angle of incidence.

How Is Gender Self-Confidence Related to Subjective Well-Being?

Science.gov (United States)

Hoffman, Rose Marie

2006-01-01

This study of ethnically diverse participants explored the relationship of gender self-confidence to subjective well-being. The 2 components of gender self-confidence (gender self-definition and gender self-acceptance) were assessed using the Hoffman Gender Scale (R. M. Hoffman, 1996; R. M. Hoffman, L. D. Borders, & J. A. Hattie, 2000). The…

The Metamemory Approach to Confidence: A Test Using Semantic Memory

Science.gov (United States)

Brewer, William F.; Sampaio, Cristina

2012-01-01

The metamemory approach to memory confidence was extended and elaborated to deal with semantic memory tasks. The metamemory approach assumes that memory confidence is based on the products and processes of a completed memory task, as well as metamemory beliefs that individuals have about how their memory products and processes relate to memory…

To protect and serve: Restoring public confidence in the SAPS ...

African Journals Online (AJOL)

Persistent incidents of brutality, criminal behaviour and abuse of authority by members of South Africa's police agencies have serious implications for public trust and confidence in the police. A decline in trust and confidence in the police is inevitably harmful to the ability of the government to reduce crime and improve public ...

Bootstrap-based confidence estimation in PCA and multivariate statistical process control

DEFF Research Database (Denmark)

Babamoradi, Hamid

be used to detect outliers in the data since the outliers can distort the bootstrap estimates. Bootstrap-based confidence limits were suggested as alternative to the asymptotic limits for control charts and contribution plots in MSPC (Paper II). The results showed that in case of the Q-statistic......Traditional/Asymptotic confidence estimation has limited applicability since it needs statistical theories to estimate the confidences, which are not available for all indicators/parameters. Furthermore, in case the theories are available for a specific indicator/parameter, the theories are based....... The goal was to improve process monitoring by improving the quality of MSPC charts and contribution plots. Bootstrapping algorithm to build confidence limits was illustrated in a case study format (Paper I). The main steps in the algorithm were discussed where a set of sensible choices (plus...

Radon emanation coefficients in sandy soils

International Nuclear Information System (INIS)

Holy, K.; Polaskova, A.; Baranova, A.; Sykora, I.; Hola, O.

1998-01-01

In this contribution the results of the study of an influence of the water content on the emanation coefficient for two sandy soil samples are reported. These samples were chosen on the because of the long-term continual monitoring of the 222 Rn concentration just in such types of soils and this radon concentration showed the significant variations during a year. These variations are chiefly given in connection with the soil moisture. Therefore, the determination of the dependence of the emanation coefficient of radon on the water content can help to evaluate the influence of the soil moisture variations of radon concentrations in the soil air. The presented results show that the emanation coefficient reaches the constant value in the wide interval of the water content for both sandy soil samples. Therefore, in the common range of the soil moisture (5 - 20 %) it is impossible to expect the variations of the radon concentration in the soil air due to the change of the emanation coefficient. The expressive changes of the radon concentration in the soil air can be observed in case of the significant decrease of the emanation coefficient during the soil drying when the water content decreases under 5 % or during the complete filling of the soil pores by the water. (authors)

Confidence Sharing in the Vocational Counselling Interview: Emergence and Repercussions

Science.gov (United States)

Olry-Louis, Isabelle; Bremond, Capucine; Pouliot, Manon

2012-01-01

Confidence sharing is an asymmetrical dialogic episode to which both parties consent, in which one reveals something personal to the other who participates in the emergence and unfolding of the confidence. We describe how this is achieved at a discursive level within vocational counselling interviews. Based on a corpus of 64 interviews, we analyse…

Friction coefficient and limiter load test analysis by flexibility coefficient model of Hold-Down Spring of nuclear reactor vessel internals

Energy Technology Data Exchange (ETDEWEB)

Xie, Linjun [Zhejiang Univ. of Technology, Hangzhou (China). College of Mechanical Engineering; Xue, Guohong; Zhang, Ming [Shanghai Nuclear Engineering Research and Design Institute, Shanghai (China)

2017-11-15

The friction force between the contact surfaces of a reactor internal hold-down spring (HDS) and core barrel flanges can directly influence the axial stiffness of an HDS. However, friction coefficient cannot be obtained through theoretical analysis. This study performs a mathematical deduction of the physical model of an HDS. Moreover, a mathematical model of axial load P, displacement δ, and flexibility coefficient is established, and a set of test apparatuses is designed to simulate the preloading process of the HDS. According to the experimental research and theoretical analysis, P-δ curves and the flexibility coefficient λ are obtained in the loading processes of the HDS. The friction coefficient f of the M1000 HDS is further calculated as 0.224. The displacement limit load value (4,638 kN) can be obtained through a displacement limit experiment. With the friction coefficient considered, the theoretical load is 4,271 kN, which is relatively close to the experimental result. Thus, the friction coefficient exerts an influence on the displacement limit load P. The friction coefficient should be considered in the design analysis for HDS.

Friction coefficient and limiter load test analysis by flexibility coefficient model of Hold-Down Spring of nuclear reactor vessel internals

International Nuclear Information System (INIS)

Xie, Linjun

2017-01-01

The friction force between the contact surfaces of a reactor internal hold-down spring (HDS) and core barrel flanges can directly influence the axial stiffness of an HDS. However, friction coefficient cannot be obtained through theoretical analysis. This study performs a mathematical deduction of the physical model of an HDS. Moreover, a mathematical model of axial load P, displacement δ, and flexibility coefficient is established, and a set of test apparatuses is designed to simulate the preloading process of the HDS. According to the experimental research and theoretical analysis, P-δ curves and the flexibility coefficient λ are obtained in the loading processes of the HDS. The friction coefficient f of the M1000 HDS is further calculated as 0.224. The displacement limit load value (4,638 kN) can be obtained through a displacement limit experiment. With the friction coefficient considered, the theoretical load is 4,271 kN, which is relatively close to the experimental result. Thus, the friction coefficient exerts an influence on the displacement limit load P. The friction coefficient should be considered in the design analysis for HDS.

Confidence Intervals from Realizations of Simulated Nuclear Data

Energy Technology Data Exchange (ETDEWEB)

Younes, W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ratkiewicz, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ressler, J. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-09-28

Various statistical techniques are discussed that can be used to assign a level of confidence in the prediction of models that depend on input data with known uncertainties and correlations. The particular techniques reviewed in this paper are: 1) random realizations of the input data using Monte-Carlo methods, 2) the construction of confidence intervals to assess the reliability of model predictions, and 3) resampling techniques to impose statistical constraints on the input data based on additional information. These techniques are illustrated with a calculation of the keff value, based on the ²³⁵U(n, f) and ²³⁹Pu (n, f) cross sections.

Exploring Self - Confidence Level of High School Students Doing Sport

Directory of Open Access Journals (Sweden)

Nurullah Emir Ekinci

2014-10-01

Full Text Available The aim of this study was to investigate self-confidence levels of high school students, who do sport, in the extent of their gender, sport branch (individual/team sports and aim for participating in sport (professional/amateur. 185 active high school students from Kutahya voluntarily participated for the study. In the study as data gathering tool self-confidence scale was used. In the evaluation of the data as a hypothesis test Mann Whitney U non parametric test was used. As a result self-confidence levels of participants showed significant differences according to their gender and sport branch but there was no significant difference according to aim for participating in sport.

Multiphoton absorption coefficients in solids: an universal curve

International Nuclear Information System (INIS)

Brandi, H.S.; Araujo, C.B. de

1983-04-01

An universal curve for the frequency dependence of the multiphoton absorption coefficient is proposed based on a 'non-perturbative' approach. Specific applications have been made to obtain two, three, four and five photons absorption coefficient in different materials. Properly scaling of the two photon absorption coefficient and the use of the universal curve yields results for the higher order absorption coefficients in good agreement with the experimental data. (Author) [pt

Does Consumer Confidence Forecast Household Saving and Borrowing Behavior? Evidence for Poland.

Science.gov (United States)

Kłopocka, Aneta Maria

2017-01-01

Consumer confidence plays an important role in households' decision-making processes. This study investigates the effects of consumer confidence on household saving and borrowing behavior that are unsatisfactorily considered in previous discussions. The questions of interest are first, whether indexes of consumer confidence have any predictive power on their own for future household saving and borrowing rates, and second, whether they contain information about future household saving and borrowing rates aside from the information contained in other available indicators. In addition to aggregate confidence indicators, their components are used to provide more precise information. Overall, the multiple linear regression analysis (OLS technique) of Polish time-series data gives positive answers to both questions. This finding supports the recommendation of combining the strengths of objective indicators (such as economic fundamentals) and subjective indicators (such as consumer confidence) to improve household financial behavior forecasts.

Confidence Intervals: From tests of statistical significance to confidence intervals, range hypotheses and substantial effects

Directory of Open Access Journals (Sweden)

Dominic Beaulieu-Prévost

2006-03-01

Full Text Available For the last 50 years of research in quantitative social sciences, the empirical evaluation of scientific hypotheses has been based on the rejection or not of the null hypothesis. However, more than 300 articles demonstrated that this method was problematic. In summary, null hypothesis testing (NHT is unfalsifiable, its results depend directly on sample size and the null hypothesis is both improbable and not plausible. Consequently, alternatives to NHT such as confidence intervals (CI and measures of effect size are starting to be used in scientific publications. The purpose of this article is, first, to provide the conceptual tools necessary to implement an approach based on confidence intervals, and second, to briefly demonstrate why such an approach is an interesting alternative to an approach based on NHT. As demonstrated in the article, the proposed CI approach avoids most problems related to a NHT approach and can often improve the scientific and contextual relevance of the statistical interpretations by testing range hypotheses instead of a point hypothesis and by defining the minimal value of a substantial effect. The main advantage of such a CI approach is that it replaces the notion of statistical power by an easily interpretable three-value logic (probable presence of a substantial effect, probable absence of a substantial effect and probabilistic undetermination. The demonstration includes a complete example.

Drag coefficient Variability and Thermospheric models

Science.gov (United States)

Moe, Kenneth

Satellite drag coefficients depend upon a variety of factors: The shape of the satellite, its altitude, the eccentricity of its orbit, the temperature and mean molecular mass of the ambient atmosphere, and the time in the sunspot cycle. At altitudes where the mean free path of the atmospheric molecules is large compared to the dimensions of the satellite, the drag coefficients can be determined from the theory of free-molecule flow. The dependence on altitude is caused by the concentration of atomic oxygen which plays an important role by its ability to adsorb on the satellite surface and thereby affect the energy loss of molecules striking the surface. The eccentricity of the orbit determines the satellite velocity at perigee, and therefore the energy of the incident molecules relative to the energy of adsorption of atomic oxygen atoms on the surface. The temperature of the ambient atmosphere determines the extent to which the random thermal motion of the molecules influences the momentum transfer to the satellite. The time in the sunspot cycle affects the ambient temperature as well as the concentration of atomic oxygen at a particular altitude. Tables and graphs will be used to illustrate the variability of drag coefficients. Before there were any measurements of gas-surface interactions in orbit, Izakov and Cook independently made an excellent estimate that the drag coefficient of satellites of compact shape would be 2.2. That numerical value, independent of altitude, was used by Jacchia to construct his model from the early measurements of satellite drag. Consequently, there is an altitude dependent bias in the model. From the sparce orbital experiments that have been done, we know that the molecules which strike satellite surfaces rebound in a diffuse angular distribution with an energy loss given by the energy accommodation coefficient. As more evidence accumulates on the energy loss, more realistic drag coefficients are being calculated. These improved drag

Calculation of transport coefficients in an axisymmetric plasma

International Nuclear Information System (INIS)

Shumaker, D.E.

1977-01-01

A method of calculating the transport coefficient in an axisymmetric toroidal plasma is presented. This method is useful in calculating the transport coefficients in a Tokamak plasma confinement device. The particle density and temperature are shown to be a constant on a magnetic flux surface. Transport equations are given for the total particle flux and total energy flux crossing a closed toroidal surface. Also transport equations are given for the toroidal magnetic flux. A computer code was written to calculate the transport coefficients for a three species plasma, electrons and two species of ions. This is useful for calculating the transport coefficients of a plasma which contains impurities. It was found that the particle and energy transport coefficients are increased by a large amount, and the transport coefficients for the toroidal magnetic field are reduced by a small amount

Experimental methodology for obtaining sound absorption coefficients

Directory of Open Access Journals (Sweden)

Carlos A. Macía M

2011-07-01

Full Text Available Objective: the authors propose a new methodology for estimating sound absorption coefficients using genetic algorithms. Methodology: sound waves are generated and conducted along a rectangular silencer. The waves are then attenuated by the absorbing material covering the silencer’s walls. The attenuated sound pressure level is used in a genetic algorithm-based search to find the parameters of the proposed attenuation expressions that include geometric factors, the wavelength and the absorption coefficient. Results: a variety of adjusted mathematical models were found that make it possible to estimate the absorption coefficients based on the characteristics of a rectangular silencer used for measuring the attenuation of the noise that passes through it. Conclusions: this methodology makes it possible to obtain the absorption coefficients of new materials in a cheap and simple manner. Although these coefficients might be slightly different from those obtained through other methodologies, they provide solutions within the engineering accuracy ranges that are used for designing noise control systems.

LIMB-DARKENING COEFFICIENTS FOR ECLIPSING WHITE DWARFS

Energy Technology Data Exchange (ETDEWEB)

Gianninas, A.; Strickland, B. D.; Kilic, Mukremin [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St., Norman, OK 73019 (United States); Bergeron, P., E-mail: alexg@nhn.ou.edu, E-mail: benstrickland@ou.edu, E-mail: kilic@ou.edu, E-mail: bergeron@astro.umontreal.ca [Departement de Physique, Universite de Montreal, C.P. 6128, Succ. Centre-Ville, Montreal, Quebec H3C 3J7 (Canada)

2013-03-20

We present extensive calculations of linear and nonlinear limb-darkening coefficients as well as complete intensity profiles appropriate for modeling the light-curves of eclipsing white dwarfs. We compute limb-darkening coefficients in the Johnson-Kron-Cousins UBVRI photometric system as well as the Large Synoptic Survey Telescope (LSST) ugrizy system using the most up to date model atmospheres available. In all, we provide the coefficients for seven different limb-darkening laws. We describe the variations of these coefficients as a function of the atmospheric parameters, including the effects of convection at low effective temperatures. Finally, we discuss the importance of having readily available limb-darkening coefficients in the context of present and future photometric surveys like the LSST, Palomar Transient Factory, and the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS). The LSST, for example, may find {approx}10{sup 5} eclipsing white dwarfs. The limb-darkening calculations presented here will be an essential part of the detailed analysis of all of these systems.

LIMB-DARKENING COEFFICIENTS FOR ECLIPSING WHITE DWARFS

International Nuclear Information System (INIS)

Gianninas, A.; Strickland, B. D.; Kilic, Mukremin; Bergeron, P.

2013-01-01

We present extensive calculations of linear and nonlinear limb-darkening coefficients as well as complete intensity profiles appropriate for modeling the light-curves of eclipsing white dwarfs. We compute limb-darkening coefficients in the Johnson-Kron-Cousins UBVRI photometric system as well as the Large Synoptic Survey Telescope (LSST) ugrizy system using the most up to date model atmospheres available. In all, we provide the coefficients for seven different limb-darkening laws. We describe the variations of these coefficients as a function of the atmospheric parameters, including the effects of convection at low effective temperatures. Finally, we discuss the importance of having readily available limb-darkening coefficients in the context of present and future photometric surveys like the LSST, Palomar Transient Factory, and the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS). The LSST, for example, may find ∼10 5 eclipsing white dwarfs. The limb-darkening calculations presented here will be an essential part of the detailed analysis of all of these systems.

Static pressure and temperature coefficients of working standard microphones

DEFF Research Database (Denmark)

Barrera Figueroa, Salvador; Cutanda Henriquez, Vicente; Torras Rosell, Antoni

2016-01-01

be a significant contribution to the uncertainty of the measurement. Determining the environmental coefficients of individual specimens of measurement microphones can be a straightforward though time-consuming procedure provided the appropriate facilities are available. An alternative is to determine them using...... coefficients. For this purpose, the environmental coefficients of some commercially available microphones have been determined experimentally, and whenever possible, compared with the coefficients determined numerically using the Boundary Element Method....... for these coefficients which are used for calibration purposes. Working standard microphones are not exempt of these influences. However, manufacturers usually provide a low frequency value of the environmental coefficient. While in some applications the influence of this coefficient may be negligible, in others it may...

Apparatus for measurement of coefficient of friction

Science.gov (United States)

Slifka, A. J.; Siegwarth, J. D.; Sparks, L. L.; Chaudhuri, Dilip K.

1990-01-01

An apparatus designed to measure the coefficient of friction in certain controlled atmospheres is described. The coefficient of friction observed during high-load tests was nearly constant, with an average value of 0.56. This value is in general agreement with that found in the literature and also with the initial friction coefficient value of 0.67 measured during self-mated friction of 440C steel in an oxygen environment.

New definition of the cell diffusion coefficient

International Nuclear Information System (INIS)

Koehler, P.

1975-01-01

As was shown in a recent work by Gelbard, the usually applied Benoist definition of the cell diffusion coefficient gives two different values if two different definitions of the cell are made. A new definition is proposed that preserves the neutron balance for the homogenized lattice and that is independent of the cell definition. The resulting diffusion coefficient is identical with the main term of Benoist's diffusion coefficient

Changing job seekers' image perceptions during recruitment visits: the moderating role of belief confidence.

Science.gov (United States)

Slaughter, Jerel E; Cable, Daniel M; Turban, Daniel B

2014-11-01

The purpose of this study was to understand how an important construct in social psychology-confidence in one's beliefs-could both (a) influence the effectiveness of organizations' recruiting processes and (b) be changed during recruitment. Using a sample of recruits to a branch of the United States military, the authors studied belief confidence before and after recruits' formal visits to the organization's recruiting stations. Personal sources of information had a stronger influence on recruits' belief confidence than impersonal sources. Moreover, recruits' confidence in their initial beliefs affected how perceptions of the recruiter changed their employer images. Among participants with low-initial confidence, the relation between recruitment experiences and employer images was positive and linear across the whole range of recruitment experiences. Among recruits with high-initial confidence, however, the recruitment experience-image relationship was curvilinear, such that recruitment experiences were related to images only at more positive recruitment experiences. The relationship between recruitment experiences and changes in belief confidence was also curvilinear, such that only more positive recruitment experiences led to changes in confidence. These results indicate not only that belief confidence influences the effectiveness of recruiting efforts but also that recruiting efforts can influence belief confidence. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

A Comparative Study of Self-Confidence from the Perspectives of Quran, Ahadith and Psychology

Directory of Open Access Journals (Sweden)

Sayyed Ali Mostajaboldavati

2017-03-01

Full Text Available Background and Objectives: Self-confidence, referring to relying on and exploiting individual abilities and talents for realizing spiritual and material prosperity, not only contradicts but is in agreement with and a prerequisite for faith in God. Practically, the greater faith in God one has, the more potent self-confidence he /she possess. Investigating the subject of self-confidence from the perspectives of Quran, Ahadith and psychology, this study explores the meaning of self (soul in self-confidence and its levels, the prerequisites for development and enhancement of self-confidence, the association of self-concept and self-esteem with self-confidence, and the approaches to develop and enhance positive self-concept as well as to boost self-confidence. Methods: The data of this descriptive review article were gathered from library and digital references. Results: Although it appears that self-confidence contradicts Islamic teachings, it can be clearly understood that this teaching subject is confirmed and emphasized in Islamic teachings by discovery of its true meaning. Conclusion: If having self-confidence is meant to rely on and exploiting individual abilities and talents to reach material and spiritual prosperity, it not only does not contradict but is in agreement with and a prerequisite for faith in God. Self in self- confidence indeed means human as a combination of the body and the spirit which is fully consistent with indices of self-confidence. According to psychologists, improving self-esteem and positive self-concept affects self-confidence directly. From perspective of religion, paying attention to venerability and God-given dignity of human, recognizing the superb purpose in life, etc. are approaches to develop and enhance positive self-concept and self-esteem, and to boost self-confidence.

A new proposal for Lagrangian correlation coefficient

International Nuclear Information System (INIS)

Altinsoy, N.; Tugrul, A.B.

2002-01-01

The statistical description of dispersion in turbulent flow was first considered by Taylor (Proc. London Math. Soc. 20 (1921) 196) and the statistical properties of the field were determined by Lagrangian correlation coefficient R L (τ). Frenkiel (Adv. Appl. Mech. 3 (1953) 61) has proposed several simple forms for R L (τ). Some workers have investigated for a proper form of the Lagrangian correlation coefficient. In this work, a new proposal for the Lagrangian correlation coefficient is proposed and discussed. It can be written in general form with the one of the Frenkiel's (Adv. Appl. Mech. 3 (1953) 61) Lagrangian correlation coefficient. There is very satisfactory agreement between the new correlation and the experiment

Leadership by Confidence in Teams

OpenAIRE

Kobayashi, Hajime; Suehiro, Hideo

2008-01-01

We study endogenous signaling by analyzing a team production problem with endogenous timing. Each agent of the team is privately endowed with some level of confidence about team productivity. Each of them must then commit a level of effort in one of two periods. At the end of each period, each agent observes his partner' s move in this period. Both agents are rewarded by a team output determined by team productivity and total invested effort. Each agent must personally incur the cost of effor...

Fuel Temperature Coefficient of Reactivity

Energy Technology Data Exchange (ETDEWEB)

Loewe, W.E.

2001-07-31

A method for measuring the fuel temperature coefficient of reactivity in a heterogeneous nuclear reactor is presented. The method, which is used during normal operation, requires that calibrated control rods be oscillated in a special way at a high reactor power level. The value of the fuel temperature coefficient of reactivity is found from the measured flux responses to these oscillations. Application of the method in a Savannah River reactor charged with natural uranium is discussed.

Virial Coefficients for the Liquid Argon

Science.gov (United States)

Korth, Micheal; Kim, Saesun

2014-03-01

We begin with a geometric model of hard colliding spheres and calculate probability densities in an iterative sequence of calculations that lead to the pair correlation function. The model is based on a kinetic theory approach developed by Shinomoto, to which we added an interatomic potential for argon based on the model from Aziz. From values of the pair correlation function at various values of density, we were able to find viral coefficients of liquid argon. The low order coefficients are in good agreement with theoretical hard sphere coefficients, but appropriate data for argon to which these results might be compared is difficult to find.

Problems with Discontinuous Diffusion/Dispersion Coefficients

Directory of Open Access Journals (Sweden)

Stefano Ferraris

2012-01-01

accurate on smooth solutions and based on a special numerical treatment of the diffusion/dispersion coefficients that makes its application possible also when such coefficients are discontinuous. Numerical experiments confirm the convergence of the numerical approximation and show a good behavior on a set of benchmark problems in two space dimensions.

Transparency as an element of public confidence

International Nuclear Information System (INIS)

Kim, H.K.

2007-01-01

In the modern society, there is increasing demands for greater transparency. It has been discussed with respect to corruption or ethics issues in social science. The need for greater openness and transparency in nuclear regulation is widely recognised as public expectations on regulator grow. It is also related to the digital and information technology that enables disclosures of every activity and information of individual and organisation, characterised by numerous 'small brothers'. Transparency has become a key word in this ubiquitous era. Transparency in regulatory activities needs to be understood in following contexts. First, transparency is one of elements to build public confidence in regulator and eventually to achieve regulatory goal of providing the public with satisfaction at nuclear safety. Transparent bases of competence, independence, ethics and integrity of working process of regulatory body would enhance public confidence. Second, activities transmitting information on nuclear safety and preparedness to be accessed are different types of transparency. Communication is an active method of transparency. With increasing use of web-sites, 'digital transparency' is also discussed as passive one. Transparency in regulatory process may be more important than that of contents. Simply providing more information is of little value and specific information may need to be protected for security reason. Third, transparency should be discussed in international, national and organizational perspectives. It has been demanded through international instruments. for each country, transparency is demanded by residents, public, NGOs, media and other stakeholders. Employees also demand more transparency in operating and regulatory organisations. Whistle-blower may appear unless they are satisfied. Fourth, pursuing transparency may cause undue social cost or adverse effects. Over-transparency may decrease public confidence and the process for transparency may also hinder

Modified Regression Correlation Coefficient for Poisson Regression Model

Science.gov (United States)

Kaengthong, Nattacha; Domthong, Uthumporn

2017-09-01

This study gives attention to indicators in predictive power of the Generalized Linear Model (GLM) which are widely used; however, often having some restrictions. We are interested in regression correlation coefficient for a Poisson regression model. This is a measure of predictive power, and defined by the relationship between the dependent variable (Y) and the expected value of the dependent variable given the independent variables [E(Y|X)] for the Poisson regression model. The dependent variable is distributed as Poisson. The purpose of this research was modifying regression correlation coefficient for Poisson regression model. We also compare the proposed modified regression correlation coefficient with the traditional regression correlation coefficient in the case of two or more independent variables, and having multicollinearity in independent variables. The result shows that the proposed regression correlation coefficient is better than the traditional regression correlation coefficient based on Bias and the Root Mean Square Error (RMSE).

Temporal correlation coefficient for directed networks.

Science.gov (United States)

Büttner, Kathrin; Salau, Jennifer; Krieter, Joachim

2016-01-01

Previous studies dealing with network theory focused mainly on the static aggregation of edges over specific time window lengths. Thus, most of the dynamic information gets lost. To assess the quality of such a static aggregation the temporal correlation coefficient can be calculated. It measures the overall possibility for an edge to persist between two consecutive snapshots. Up to now, this measure is only defined for undirected networks. Therefore, we introduce the adaption of the temporal correlation coefficient to directed networks. This new methodology enables the distinction between ingoing and outgoing edges. Besides a small example network presenting the single calculation steps, we also calculated the proposed measurements for a real pig trade network to emphasize the importance of considering the edge direction. The farm types at the beginning of the pork supply chain showed clearly higher values for the outgoing temporal correlation coefficient compared to the farm types at the end of the pork supply chain. These farm types showed higher values for the ingoing temporal correlation coefficient. The temporal correlation coefficient is a valuable tool to understand the structural dynamics of these systems, as it assesses the consistency of the edge configuration. The adaption of this measure for directed networks may help to preserve meaningful additional information about the investigated network that might get lost if the edge directions are ignored.

Kubo Formulas for Second-Order Hydrodynamic Coefficients

International Nuclear Information System (INIS)

Moore, Guy D.; Sohrabi, Kiyoumars A.

2011-01-01

At second order in gradients, conformal relativistic hydrodynamics depends on the viscosity η and on five additional ''second-order'' hydrodynamical coefficients τ Π , κ, λ 1 , λ 2 , and λ 3 . We derive Kubo relations for these coefficients, relating them to equilibrium, fully retarded three-point correlation functions of the stress tensor. We show that the coefficient λ 3 can be evaluated directly by Euclidean means and does not in general vanish.

78 FR 57538 - Proposed Waste Confidence Rule and Draft Generic Environmental Impact Statement

Science.gov (United States)

2013-09-19

..., Chief, Communication, Planning, and Rulemaking Branch Waste Confidence Directorate, Office of Nuclear...-2012-0246] RIN 3150-AJ20 Proposed Waste Confidence Rule and Draft Generic Environmental Impact... disposal (proposed Waste Confidence rule). In addition, the NRC will receive public comment on its...

Investigating the psychological resilience, self-confidence and problem-solving skills of midwife candidates.

Science.gov (United States)

Ertekin Pinar, Sukran; Yildirim, Gulay; Sayin, Neslihan

2018-05-01

The high level of psychological resilience, self-confidence and problem solving skills of midwife candidates play an important role in increasing the quality of health care and in fulfilling their responsibilities towards patients. This study was conducted to investigate the psychological resilience, self-confidence and problem-solving skills of midwife candidates. It is a convenience descriptive quantitative study. Students who study at Health Sciences Faculty in Turkey's Central Anatolia Region. Midwife candidates (N = 270). In collection of data, the Personal Information Form, Psychological Resilience Scale for Adults (PRSA), Self-Confidence Scale (SCS), and Problem Solving Inventory (PSI) were used. There was a negatively moderate-level significant relationship between the Problem Solving Inventory scores and the Psychological Resilience Scale for Adults scores (r = -0.619; p = 0.000), and between Self-Confidence Scale scores (r = -0.524; p = 0.000). There was a positively moderate-level significant relationship between the Psychological Resilience Scale for Adults scores and the Self-Confidence Scale scores (r = 0.583; p = 0.000). There was a statistically significant difference (p Problem Solving Inventory and the Psychological Resilience Scale for Adults scores according to getting support in a difficult situation. As psychological resilience and self-confidence levels increase, problem-solving skills increase; additionally, as self-confidence increases, psychological resilience increases too. Psychological resilience, self-confidence, and problem-solving skills of midwife candidates in their first-year of studies are higher than those who are in their fourth year. Self-confidence and psychological resilience of midwife candidates aged between 17 and 21, self-confidence and problem solving skills of residents of city centers, psychological resilience of those who perceive their monthly income as sufficient are high

Irrational "Coefficients" in Renaissance Algebra.

Science.gov (United States)

Oaks, Jeffrey A

2017-06-01

Argument From the time of al-Khwārizmī in the ninth century to the beginning of the sixteenth century algebraists did not allow irrational numbers to serve as coefficients. To multiply by x, for instance, the result was expressed as the rhetorical equivalent of . The reason for this practice has to do with the premodern concept of a monomial. The coefficient, or "number," of a term was thought of as how many of that term are present, and not as the scalar multiple that we work with today. Then, in sixteenth-century Europe, a few algebraists began to allow for irrational coefficients in their notation. Christoff Rudolff (1525) was the first to admit them in special cases, and subsequently they appear more liberally in Cardano (1539), Scheubel (1550), Bombelli (1572), and others, though most algebraists continued to ban them. We survey this development by examining the texts that show irrational coefficients and those that argue against them. We show that the debate took place entirely in the conceptual context of premodern, "cossic" algebra, and persisted in the sixteenth century independent of the development of the new algebra of Viète, Decartes, and Fermat. This was a formal innovation violating prevailing concepts that we propose could only be introduced because of the growing autonomy of notation from rhetorical text.

Activity coefficients of electrons and holes in semiconductors

International Nuclear Information System (INIS)

Orazem, M.E.; Newman, J.

1984-01-01

Dilute-solution transport equations with constant activity coefficients are commonly used to model semiconductors. These equations are consistent with a Boltzmann distribution and are invalid in regions where the species concentration is close to the respective site concentration. A more rigorous treatment of transport in a semiconductor requires activity coefficients which are functions of concentration. Expressions are presented for activity coefficients of electrons and holes in semiconductors for which conduction- and valence-band energy levels are given by the respective bandedge energy levels. These activity coefficients are functions of concentration and are thermodynamically consistent. The use of activity coefficients in macroscopic transport relationships allows a description of electron transport in a manner consistent with the Fermi-Dirac distribution

Coefficients of conservatism for the vascular flora of the Dakotas and adjacent grasslands

Science.gov (United States)

,

2001-01-01

Floristic quality assessment can be used to identity natural areas, to facilitate comparisons among different sites, to provide long-term monitoring of natural area quality, and to evaluate habitat management and restoration efforts. To facilitate the use of floristic quality assessment in North Dakota, South Dakota (excluding the Black Hills), and adjacent grasslands, we developed a species list and assigned coefficients of conservatism (C values; range 0 to 10) to each plant species in the region's flora. The C values we assigned represented our collective knowledge of the patterns of occurrence of each plant species in the Dakotas and our confidence that a particular taxon is natural-area dependent. Because state boundaries usually do not follow ecological boundaries, the C values we assigned should be equally valid in nearby areas with the same vegetation types. Of the 1,584 taxa we recognized in this effort, 275 (17%) were determined to be nonnative to the region. We assigned C values of 4 or higher to 77% of our taxa, and the entire native flora had a mean C value (C) of 6.l. A floristic quality index (FQI) can be calculated to rank sites in order of their floristic quality. By applying the coefficients of conservatism supplied here and calculating C and FQI, an effective means of evaluating the quality of plant communities can be obtained. Additionally, by repeating plant surveys and calculations of C and FQI over time, temporal changes in floristic quality can be identified.

Extracting electron backscattering coefficients from backscattered electron micrographs

International Nuclear Information System (INIS)

Zupanic, F.

2010-01-01

Electron backscattering micrographs possess the so-called Z-contrast, carrying information about the chemical compositions of phases present in microstructures. The intensity at a particular point in the backscattered electron micrograph is proportional to the signal detected at a corresponding point in the scan raster, which is, in turn, proportional to the electron backscattering coefficient of a phase at that point. This article introduces a simple method for extracting the electron backscattering coefficients of phases present in the microstructure, from the backscattered electron micrographs. This method is able to convert the micrograph's greyscale to the backscattering-coefficient-scale. The prerequisite involves the known backscattering coefficients for two phases in the micrograph. In this way, backscattering coefficients of other phases can be determined. The method is unable to determine the chemical compositions of phases or the presence of an element only from analysing the backscattered electron micrograph. Nevertheless, this method was found to be very powerful when combined with energy dispersive spectroscopy, and the calculations of backscattering coefficients. - Research Highlights: →A simple method for extracting the electron backscattering coefficients →The prerequisite is known backscattering coefficients for two phases →The information is complementary to the EDS-results. →This method is especially useful when a phase contains a light element (H, Li, Be, and B)

Attenuation coefficients of soils

International Nuclear Information System (INIS)

Martini, E.; Naziry, M.J.

1989-01-01

As a prerequisite to the interpretation of gamma-spectrometric in situ measurements of activity concentrations of soil radionuclides the attenuation of 60 to 1332 keV gamma radiation by soil samples varying in water content and density has been investigated. A useful empirical equation could be set up to describe the dependence of the mass attenuation coefficient upon photon energy for soil with a mean water content of 10%, with the results comparing well with data in the literature. The mean density of soil in the GDR was estimated at 1.6 g/cm 3 . This value was used to derive the linear attenuation coefficients, their range of variation being 10%. 7 figs., 5 tabs. (author)

Anomaly coefficients: Their calculation and congruences

International Nuclear Information System (INIS)

Braden, H.W.

1988-01-01

A new method for the calculation of anomaly coefficients is presented. For su(n) some explicit and general expressions are given for these. In particular, certain congruences are discovered and investigated among the leading anomaly coefficients. As an application of these congruences, the absence of global six-dimensional gauge anomalies is shown

Diagnosing Anomalous Network Performance with Confidence

Energy Technology Data Exchange (ETDEWEB)

Settlemyer, Bradley W [ORNL; Hodson, Stephen W [ORNL; Kuehn, Jeffery A [ORNL; Poole, Stephen W [ORNL

2011-04-01

Variability in network performance is a major obstacle in effectively analyzing the throughput of modern high performance computer systems. High performance interconnec- tion networks offer excellent best-case network latencies; how- ever, highly parallel applications running on parallel machines typically require consistently high levels of performance to adequately leverage the massive amounts of available computing power. Performance analysts have usually quantified network performance using traditional summary statistics that assume the observational data is sampled from a normal distribution. In our examinations of network performance, we have found this method of analysis often provides too little data to under- stand anomalous network performance. Our tool, Confidence, instead uses an empirically derived probability distribution to characterize network performance. In this paper we describe several instances where the Confidence toolkit allowed us to understand and diagnose network performance anomalies that we could not adequately explore with the simple summary statis- tics provided by traditional measurement tools. In particular, we examine a multi-modal performance scenario encountered with an Infiniband interconnection network and we explore the performance repeatability on the custom Cray SeaStar2 interconnection network after a set of software and driver updates.

A new consistent definition of the homogenized diffusion coefficient of a lattice, limitations of the homogenization concept, and discussion of previously defined coefficients

International Nuclear Information System (INIS)

Deniz, V.C.

1978-01-01

The problem concerned with the correct definition of the homogenized diffusion coefficient of a lattice, and the concurrent problem of whether or not a homogenized diffusion equation can be formally set up, is studied by a space-energy angle dependent treatment for a general lattice cell; using an operator notation which applies to any eigen-problem. It is shown that the diffusion coefficient should represent only leakage effects. A new definition of the diffusion coefficient is given, which combines within itself the individual merits of each of the two definitions of Benoist, and reduces to the 'uncorrected' Benoist coefficient in certain cases. The conditions under which a homogenized diffusion equation can be obtained are discussed. A compatison is made between the approach via a diffusion equation and the approach via the eigen-coefficients of Deniz. Previously defined diffusion coefficients are discussed, and it is shown that the transformed eigen-coefficients proposed by Gelbard and by Larsen are unsuitable as diffusion coefficients, and that the cell-edge normalization of the Bonalumi coefficient is not physically justifiable. (author)

Validation of an instrument to assess evidence-based practice knowledge, attitudes, access, and confidence in the dental environment.

Science.gov (United States)

Hendricson, William D; Rugh, John D; Hatch, John P; Stark, Debra L; Deahl, Thomas; Wallmann, Elizabeth R

2011-02-01

This article reports the validation of an assessment instrument designed to measure the outcomes of training in evidence-based practice (EBP) in the context of dentistry. Four EBP dimensions are measured by this instrument: 1) understanding of EBP concepts, 2) attitudes about EBP, 3) evidence-accessing methods, and 4) confidence in critical appraisal. The instrument-the Knowledge, Attitudes, Access, and Confidence Evaluation (KACE)-has four scales, with a total of thirty-five items: EBP knowledge (ten items), EBP attitudes (ten), accessing evidence (nine), and confidence (six). Four elements of validity were assessed: consistency of items within the KACE scales (extent to which items within a scale measure the same dimension), discrimination (capacity to detect differences between individuals with different training or experience), responsiveness (capacity to detect the effects of education on trainees), and test-retest reliability. Internal consistency of scales was assessed by analyzing responses of second-year dental students, dental residents, and dental faculty members using Cronbach coefficient alpha, a statistical measure of reliability. Discriminative validity was assessed by comparing KACE scores for the three groups. Responsiveness was assessed by comparing pre- and post-training responses for dental students and residents. To measure test-retest reliability, the full KACE was completed twice by a class of freshman dental students seventeen days apart, and the knowledge scale was completed twice by sixteen faculty members fourteen days apart. Item-to-scale consistency ranged from 0.21 to 0.78 for knowledge, 0.57 to 0.83 for attitude, 0.70 to 0.84 for accessing evidence, and 0.87 to 0.94 for confidence. For discrimination, ANOVA and post hoc testing by the Tukey-Kramer method revealed significant score differences among students, residents, and faculty members consistent with education and experience levels. For responsiveness to training, dental students

Distribution of the product confidence limits for the indirect effect: Program PRODCLIN

Science.gov (United States)

MacKinnon, David P.; Fritz, Matthew S.; Williams, Jason; Lockwood, Chondra M.

2010-01-01

This article describes a program, PRODCLIN (distribution of the PRODuct Confidence Limits for INdirect effects), written for SAS, SPSS, and R, that computes confidence limits for the product of two normal random variables. The program is important because it can be used to obtain more accurate confidence limits for the indirect effect, as demonstrated in several recent articles (MacKinnon, Lockwood, & Williams, 2004; Pituch, Whittaker, & Stapleton, 2005). Tests of the significance of and confidence limits for indirect effects based on the distribution of the product method have more accurate Type I error rates and more power than other, more commonly used tests. Values for the two paths involved in the indirect effect and their standard errors are entered in the PRODCLIN program, and distribution of the product confidence limits are computed. Several examples are used to illustrate the PRODCLIN program. The PRODCLIN programs in rich text format may be downloaded from www.psychonomic.org/archive. PMID:17958149

Building confidence: an exploration of nurses undertaking a postgraduate biological science course.

Science.gov (United States)

Van Wissen, Kim; McBride-Henry, Karen

2010-01-01

This study aimed to explore the impact of studying biological science at a postgraduate level and how this impacted on nursing practice. The term biological sciences in this research encompasses elements of physiology, genetics, biochemistry and pathophysiology. A qualitative research study was designed, that involved the dissemination of a pre- and post-course semi-structured questionnaire for a biological science course, as part of a Master of Nursing programme at a New Zealand University, thus exploring the impact of undertaking a postgraduate biological sciences course. The responses were analysed into themes, based on interpretive concepts. The primary themes revealed improvement in confidence as: confidence in communication, confidence in linking nursing theoretical knowledge to practice and confidence in clinical nursing knowledge. This study highlights the need to privilege clinically-derived nursing knowledge, and that confidence in this nursing knowledge and clinical practice can be instilled through employing the model of theory-guided practice.

Continuous Opinion Dynamics Under Bounded Confidence:. a Survey

Science.gov (United States)

Lorenz, Jan

Models of continuous opinion dynamics under bounded confidence have been presented independently by Krause and Hegselmann and by Deffuant et al. in 2000. They have raised a fair amount of attention in the communities of social simulation, sociophysics and complexity science. The researchers working on it come from disciplines such as physics, mathematics, computer science, social psychology and philosophy. In these models agents hold continuous opinions which they can gradually adjust if they hear the opinions of others. The idea of bounded confidence is that agents only interact if they are close in opinion to each other. Usually, the models are analyzed with agent-based simulations in a Monte Carlo style, but they can also be reformulated on the agent's density in the opinion space in a master equation style. The contribution of this survey is fourfold. First, it will present the agent-based and density-based modeling frameworks including the cases of multidimensional opinions and heterogeneous bounds of confidence. Second, it will give the bifurcation diagrams of cluster configuration in the homogeneous model with uniformly distributed initial opinions. Third, it will review the several extensions and the evolving phenomena which have been studied so far, and fourth it will state some open questions.

A general model of confidence building: analysis and implications

International Nuclear Information System (INIS)

Kilgour, D.M.

1998-01-01

For more than two decades, security approaches in Europe have included confidence building. Many have argued that Confidence-Building Measures (CBMS) played an essential role in the enormous transformations that took place there. Thus, it is hardly,surprising that CBMs have been proposed as measures to reduce tensions and transform security relationships elsewhere in the world. The move toward wider application of CBMs has strengthened recently, as conventional military, diplomatic, and humanitarian approaches seem to have failed to address problems associated with peace-building and peace support operations. There is, however, a serious problem. We don't really know why, or even how, CBMs work. Consequently, we have no reliable way to design CBMs that would be appropriate in substance, form, and timing for regions culturally, geographically, and militarily different from Europe. Lacking a solid understanding of confidence building, we are handicapped in our efforts to extend its successes to the domain of peace building and peace support. To paraphrase Macintosh, if we don't know how CBMs succeeded in the past, then we are unlikely to be good at maintaining, improving, or extending them. The specific aim of this project is to step into this gap, using the methods of game theory to clarify some aspects of the underlying logic of confidence building. Formal decision models will be shown to contribute new and valuable insights that will assist in the design of CBMs to contribute to new problems and in new arenas. (author)

Probability based calibration of pressure coefficients

DEFF Research Database (Denmark)

Hansen, Svend Ole; Pedersen, Marie Louise; Sørensen, John Dalsgaard

2015-01-01

Normally, a consistent basis for calculating partial factors focuses on a homogeneous reliability index neither depending on which material the structure is constructed of nor the ratio between the permanent and variable actions acting on the structure. Furthermore, the reliability index should n...... the characteristic shape coefficients are based on mean values as specified in background documents to the Eurocodes. Importance of hidden safeties judging the reliability is discussed for wind actions on low-rise structures....... not depend on the type of variable action. A probability based calibration of pressure coefficients have been carried out using pressure measurements on the standard CAARC building modelled on scale of 1:383. The extreme pressures measured on the CAARC building model in the wind tunnel have been fitted.......3, the Eurocode partial factor of 1.5 for variable actions agrees well with the inherent uncertainties of wind actions when the pressure coefficients are determined using wind tunnel test results. The increased bias and uncertainty when pressure coefficients mainly are based on structural codes lead to a larger...

Axially symmetric reconstruction of plasma emission and absorption coefficients

International Nuclear Information System (INIS)

Yang Lixin; Jia Hui; Yang Jiankun; Li Xiujian; Chen Shaorong; Liu Xishun

2013-01-01

A layered structure imaging model is developed in order to reconstruct emission coefficients and absorption coefficients simultaneously, in laser fusion core plasma diagnostics. A novel axially symmetric reconstruction method that utilizes the LM (Levenberg-Marquardt) nonlinear least squares minimization algorithm is proposed based on the layered structure. Numerical simulation results demonstrate that the proposed method is sufficiently accurate to reconstruct emission coefficients and absorption coefficients, and when the standard deviation of noise is 0.01, the errors of emission coefficients and absorption coefficients are 0.17, 0.22, respectively. Furthermore, this method could perform much better on reconstruction effect compared with traditional inverse Abel transform algorithms. (authors)

Estimating Runoff Coefficients Using Weather Radars

DEFF Research Database (Denmark)

Ahm, Malte; Thorndahl, Søren Liedtke; Rasmussen, Michael R.

2012-01-01

This paper presents a method for estimating runoff coefficients of urban drainage catchments based on a combination of high resolution weather radar data and insewer flow measurements. By utilising the spatial variability of the precipitation it is possible to estimate the runoff coefficients...... of separate subcatchments. The method is demonstrated through a case study of an urban drainage catchment (678ha) located in the municipality of Aarhus, Denmark. The study has proven it is possible to use corresponding measurements of the relative rainfall distribution over the catchment and runoff...... measurements to identify the runoff coefficients at subcatchment level. The number of potential subcatchments is limited by the number of available rainfall events with a sufficient spatial variability....

Lower Confidence Bounds for the Probabilities of Correct Selection

Directory of Open Access Journals (Sweden)

Radhey S. Singh

2011-01-01

Full Text Available We extend the results of Gupta and Liang (1998, derived for location parameters, to obtain lower confidence bounds for the probability of correctly selecting the t best populations (PCSt simultaneously for all t=1,…,k−1 for the general scale parameter models, where k is the number of populations involved in the selection problem. The application of the results to the exponential and normal probability models is discussed. The implementation of the simultaneous lower confidence bounds for PCSt is illustrated through real-life datasets.

Metacognitive Confidence Increases with, but Does Not Determine, Visual Perceptual Learning.

Science.gov (United States)

Zizlsperger, Leopold; Kümmel, Florian; Haarmeier, Thomas

2016-01-01

While perceptual learning increases objective sensitivity, the effects on the constant interaction of the process of perception and its metacognitive evaluation have been rarely investigated. Visual perception has been described as a process of probabilistic inference featuring metacognitive evaluations of choice certainty. For visual motion perception in healthy, naive human subjects here we show that perceptual sensitivity and confidence in it increased with training. The metacognitive sensitivity-estimated from certainty ratings by a bias-free signal detection theoretic approach-in contrast, did not. Concomitant 3Hz transcranial alternating current stimulation (tACS) was applied in compliance with previous findings on effective high-low cross-frequency coupling subserving signal detection. While perceptual accuracy and confidence in it improved with training, there were no statistically significant tACS effects. Neither metacognitive sensitivity in distinguishing between their own correct and incorrect stimulus classifications, nor decision confidence itself determined the subjects' visual perceptual learning. Improvements of objective performance and the metacognitive confidence in it were rather determined by the perceptual sensitivity at the outset of the experiment. Post-decision certainty in visual perceptual learning was neither independent of objective performance, nor requisite for changes in sensitivity, but rather covaried with objective performance. The exact functional role of metacognitive confidence in human visual perception has yet to be determined.

Diffusion coefficient adaptive correction in Lagrangian puff model

International Nuclear Information System (INIS)

Tan Wenji; Wang Dezhong; Ma Yuanwei; Ji Zhilong

2014-01-01

Lagrangian puff model is widely used in the decision support system for nuclear emergency management. The diffusion coefficient is one of the key parameters impacting puff model. An adaptive method was proposed in this paper, which could correct the diffusion coefficient in Lagrangian puff model, and it aimed to improve the accuracy of calculating the nuclide concentration distribution. This method used detected concentration data, meteorological data and source release data to estimate the actual diffusion coefficient with least square method. The diffusion coefficient adaptive correction method was evaluated by Kincaid data in MVK, and was compared with traditional Pasquill-Gifford (P-G) diffusion scheme method. The results indicate that this diffusion coefficient adaptive correction method can improve the accuracy of Lagrangian puff model. (authors)

Taylor coefficients and coefficient multipliers of Hardy and Bergman-type spaces

CERN Document Server

Jevtić, Miroljub; Arsenović, Miloš

2016-01-01

This book provides a systematic overview of the theory of Taylor coefficients of functions in some classical spaces of analytic functions and especially of the coefficient multipliers between spaces of Hardy type. Offering a comprehensive reference guide to the subject, it is the first of its kind in this area. After several introductory chapters covering the basic material, a large variety of results obtained over the past 80 years, including the most recent ones, are treated in detail. Several chapters end with discussions of practical applications and related topics that graduate students and experts in other subjects may find useful for their own purposes. Thus, a further aim of the book is to communicate to non-specialists some concrete facts that may be of value in their own work. The book can also be used as a textbook or a supplementary reference for an advanced graduate course. It is primarily intended for specialists in complex and functional analysis, graduate students, and experts in other related...

Roughness coefficient and its uncertainty in gravel-bed river

Directory of Open Access Journals (Sweden)

Ji-Sung Kim

2010-06-01

Full Text Available Manning's roughness coefficient was estimated for a gravel-bed river reach using field measurements of water level and discharge, and the applicability of various methods used for estimation of the roughness coefficient was evaluated. Results show that the roughness coefficient tends to decrease with increasing discharge and water depth, and over a certain range it appears to remain constant. Comparison of roughness coefficients calculated by field measurement data with those estimated by other methods shows that, although the field-measured values provide approximate roughness coefficients for relatively large discharge, there seems to be rather high uncertainty due to the difference in resultant values. For this reason, uncertainty related to the roughness coefficient was analyzed in terms of change in computed variables. On average, a 20% increase of the roughness coefficient causes a 7% increase in the water depth and an 8% decrease in velocity, but there may be about a 15% increase in the water depth and an equivalent decrease in velocity for certain cross-sections in the study reach. Finally, the validity of estimated roughness coefficient based on field measurements was examined. A 10% error in discharge measurement may lead to more than 10% uncertainty in roughness coefficient estimation, but corresponding uncertainty in computed water depth and velocity is reduced to approximately 5%. Conversely, the necessity for roughness coefficient estimation by field measurement is confirmed.

A gain-coefficient switched Alexandrite laser

International Nuclear Information System (INIS)

Lee, Chris J; Van der Slot, Peter J M; Boller, Klaus-J

2013-01-01

We report on a gain-coefficient switched Alexandrite laser. An electro-optic modulator is used to switch between high and low gain states by making use of the polarization dependent gain of Alexandrite. In gain-coefficient switched mode, the laser produces 85 ns pulses with a pulse energy of 240 mJ at a repetition rate of 5 Hz.

Confidence-building measures in the Asia-Pacific region

International Nuclear Information System (INIS)

Qin Huasun

1991-01-01

The regional confidence-building, security and disarmament issues in the Asia-Pacific region, and in particular, support to non-proliferation regime and establishing nuclear-weapon-free zones are reviewed

Effect of immersive workplace experience on undergraduate nurses' mental health clinical confidence.

Science.gov (United States)

Patterson, Christopher; Moxham, Lorna; Taylor, Ellie K; Perlman, Dana; Brighton, Renee; Sumskis, Susan; Heffernan, Tim; Lee-Bates, Benjamin

2017-12-01

Preregistration education needs to ensure that student nurses are properly trained with the required skills and knowledge, and have the confidence to work with people who have a mental illness. With increased attention on non-traditional mental health clinical placements, further research is required to determine the effects of non-traditional mental health clinical placements on mental health clinical confidence. The aim of the present study was to investigate the impact of a non-traditional mental health clinical placement on mental health nursing clinical confidence compared to nursing students undergoing traditional clinical placements. Using the Mental Health Nursing Clinical Confidence Scale, the study investigated the relative effects of two placement programmes on the mental health clinical confidence of 79 nursing students. The two placement programmes included a non-traditional clinical placement of Recovery Camp and a comparison group that attended traditional clinical placements. Overall, the results indicated that, for both groups, mental health placement had a significant effect on improving mean mental health clinical confidence, both immediately upon conclusion of placement and at the 3-month follow up. Students who attended Recovery Camp reported a significant positive difference, compared to the comparison group, for ratings related to communicating effectively with clients with a mental illness, having a basic knowledge of antipsychotic medications and their side-effects, and providing client education regarding the effects and side-effects of medications. The findings suggest that a unique clinical placement, such as Recovery Camp, can improve and maintain facets of mental health clinical confidence for students of nursing. © 2017 Australian College of Mental Health Nurses Inc.

Quantum Non-Markovian Langevin Equations and Transport Coefficients

International Nuclear Information System (INIS)

Sargsyan, V.V.; Antonenko, N.V.; Kanokov, Z.; Adamian, G.G.

2005-01-01

Quantum diffusion equations featuring explicitly time-dependent transport coefficients are derived from generalized non-Markovian Langevin equations. Generalized fluctuation-dissipation relations and analytic expressions for calculating the friction and diffusion coefficients in nuclear processes are obtained. The asymptotic behavior of the transport coefficients and correlation functions for a damped harmonic oscillator that is linearly coupled in momentum to a heat bath is studied. The coupling to a heat bath in momentum is responsible for the appearance of the diffusion coefficient in coordinate. The problem of regression of correlations in quantum dissipative systems is analyzed

Empowerment as Interactions that Generate Self-Confidence

DEFF Research Database (Denmark)

Poder, Poul

2010-01-01

to address this gap in understanding by theorizing how confidence and other positive emotions contribute to personal agency, which is an essential aspect of the empowerment process.                       It is generally understood that confidence – meaning faith in oneself as opposed to conceit or arrogance...... by particular social interactions that promote recognition and access to relevant resources for action. Drawing on emotion-focused sociological theory about agency and emotional energy, and Fredrickson’s ‘build and broaden’ theory of positive emotions, I argue that the focus on consciousness and intentionality...... as the defining features of human agency has led us to downplay the fact that agency is primarily an emotional phenomenon. As such, it is also dynamic and situational, since it is highly dependent on interactions that engender emotional energy and positive emotions that fuel and widen agency. As an example...

Roughness coefficients for stream channels in Arizona

Science.gov (United States)

Aldridge, B.N.; Garrett, J.M.

1973-01-01

When water flows in an open channel, energy is lost through friction along the banks and bed of the channel and through turbulence within the channel. The amount of energy lost is governed by channel roughness, which is expressed in terms of a roughness coefficient. An evaluation of the roughness coefficient is necessary in many hydraulic computations that involve flow in an open channel. Owing to the lack of satisfactory quantitative procedure, the ability of evaluate roughness coefficients can be developed only through experience; however, a basic knowledge of the methods used to assign the coefficients and the factors affecting them will be a great help. One of the most commonly used equations in open-channel hydraulics is that of Manning. The Manning equation is       1.486

Heat conduction coefficient and coefficient of linear thermal expansion of electric insulation materials for superconducting magnetic system

International Nuclear Information System (INIS)

Deev, V.I.; Sobolev, V.P.; Kruglov, A.B.; Pridantsev, A.I.

1984-01-01

Results of experimental investigation of heat conduction coefficient and coefficient of linear thermal expansion and thermal shrinkages of the STEF-1 textolite-glass widely used in superconducting magnetic systems as electric insulating and structural material are presented. Samples of two types have been died: sample axisa is perpendicular to a plae of fiberglass layers ad sample axis is parallel to a plane of fiberglass layers. Heat conduction coefficient was decreased almost a five times with temperature decrease from 300 up to 5K and was slightly dependent on a sample type. Temperature variation of linear dimensions in a sample of the first type occurs in twice as fast as compared to the sample of the second type

The confidence of speech-language pathology students regarding communicating with people with aphasia

Science.gov (United States)

2013-01-01

Background Aphasia is an acquired language disorder that can present a significant barrier to patient involvement in healthcare decisions. Speech-language pathologists (SLPs) are viewed as experts in the field of communication. However, many SLP students do not receive practical training in techniques to communicate with people with aphasia (PWA) until they encounter PWA during clinical education placements. Methods This study investigated the confidence and knowledge of SLP students in communicating with PWA prior to clinical placements using a customised questionnaire. Confidence in communicating with people with aphasia was assessed using a 100-point visual analogue scale. Linear, and logistic, regressions were used to examine the association between confidence and age, as well as confidence and course type (graduate-entry masters or undergraduate), respectively. Knowledge of strategies to assist communication with PWA was examined by asking respondents to list specific strategies that could assist communication with PWA. Results SLP students were not confident with the prospect of communicating with PWA; reporting a median 29-points (inter-quartile range 17–47) on the visual analogue confidence scale. Only, four (8.2%) of respondents rated their confidence greater than 55 (out of 100). Regression analyses indicated no relationship existed between confidence and students‘ age (p = 0.31, r-squared = 0.02), or confidence and course type (p = 0.22, pseudo r-squared = 0.03). Students displayed limited knowledge about communication strategies. Thematic analysis of strategies revealed four overarching themes; Physical, Verbal Communication, Visual Information and Environmental Changes. While most students identified potential use of resources (such as images and written information), fewer students identified strategies to alter their verbal communication (such as reduced speech rate). Conclusions SLP students who had received aphasia related

The confidence of speech-language pathology students regarding communicating with people with aphasia.

Science.gov (United States)

Finch, Emma; Fleming, Jennifer; Brown, Kyla; Lethlean, Jennifer; Cameron, Ashley; McPhail, Steven M

2013-06-27

Aphasia is an acquired language disorder that can present a significant barrier to patient involvement in healthcare decisions. Speech-language pathologists (SLPs) are viewed as experts in the field of communication. However, many SLP students do not receive practical training in techniques to communicate with people with aphasia (PWA) until they encounter PWA during clinical education placements. This study investigated the confidence and knowledge of SLP students in communicating with PWA prior to clinical placements using a customised questionnaire. Confidence in communicating with people with aphasia was assessed using a 100-point visual analogue scale. Linear, and logistic, regressions were used to examine the association between confidence and age, as well as confidence and course type (graduate-entry masters or undergraduate), respectively. Knowledge of strategies to assist communication with PWA was examined by asking respondents to list specific strategies that could assist communication with PWA. SLP students were not confident with the prospect of communicating with PWA; reporting a median 29-points (inter-quartile range 17-47) on the visual analogue confidence scale. Only, four (8.2%) of respondents rated their confidence greater than 55 (out of 100). Regression analyses indicated no relationship existed between confidence and students' age (p = 0.31, r-squared = 0.02), or confidence and course type (p = 0.22, pseudo r-squared = 0.03). Students displayed limited knowledge about communication strategies. Thematic analysis of strategies revealed four overarching themes; Physical, Verbal Communication, Visual Information and Environmental Changes. While most students identified potential use of resources (such as images and written information), fewer students identified strategies to alter their verbal communication (such as reduced speech rate). SLP students who had received aphasia related theoretical coursework, but not commenced clinical placements

The relationship between fundamental movement skill proficiency and physical self-confidence among adolescents.

Science.gov (United States)

McGrane, Bronagh; Belton, Sarahjane; Powell, Danielle; Issartel, Johann

2017-09-01

This study aims to assess fundamental movement skill (FMS) proficiency, physical self-confidence levels, and the relationship between these variables and gender differences among adolescents. Three hundred and ninety five adolescents aged 13.78 years (SD = ±1.2) from 20 schools were involved in this study. The Test of Gross Motor Development-2nd Edition (TGMD), TGMD-2 and Victorian Skills Manual were used to assess 15 FMS. Participants' physical self-confidence was also assessed using a valid skill-specific scale. A significant correlation was observed between FMS proficiency and physical self-confidence for females only (r = 0.305, P < 0.001). Males rated themselves as having significantly higher physical self-confidence levels than females (P = 0.001). Males scored significantly higher than females in FMS proficiency (P < 0.05), and the lowest physical self-confidence group were significantly less proficient at FMS than the medium (P < 0.001) and high physical self-confidence groups (P < 0.05). This information not only highlights those in need of assistance to develop their FMS but will also facilitate in the development of an intervention which aims to improve physical self-confidence and FMS proficiency.

Breakdown coefficients and scaling properties of rain fields

Directory of Open Access Journals (Sweden)

D. Harris

1998-01-01

Full Text Available The theory of scale similarity and breakdown coefficients is applied here to intermittent rainfall data consisting of time series and spatial rain fields. The probability distributions (pdf of the logarithm of the breakdown coefficients are the principal descriptor used. Rain fields are distinguished as being either multiscaling or multiaffine depending on whether the pdfs of breakdown coefficients are scale similar or scale dependent, respectively. Parameter  estimation techniques are developed which are applicable to both multiscaling and multiaffine fields. The scale parameter (width, σ, of the pdfs of the log-breakdown coefficients is a measure of the intermittency of a field. For multiaffine fields, this scale parameter is found to increase with scale in a power-law fashion consistent with a bounded-cascade picture of rainfall modelling. The resulting power-law exponent, H, is indicative of the smoothness of the field. Some details of breakdown coefficient analysis are addressed and a theoretical link between this analysis and moment scaling analysis is also presented. Breakdown coefficient properties of cascades are also investigated in the context of parameter estimation for modelling purposes.

A National Survey of Music Education Majors' Confidence in Teaching Improvisation

Science.gov (United States)

Bernhard, H. Christian, II.; Stringham, David A.

2016-01-01

The purpose of the study was to investigate undergraduate music education majors' confidence in teaching improvisation, according to the NAfME (1994) K-12 Achievement Standards. Specific research questions were: 1) How confident are music education majors in implementing the 11 improvisation achievement standards for grades K-12? 2) How confident…

Confidence Limits for the Indirect Effect: Distribution of the Product and Resampling Methods

Science.gov (United States)

MacKinnon, David P.; Lockwood, Chondra M.; Williams, Jason

2010-01-01

The most commonly used method to test an indirect effect is to divide the estimate of the indirect effect by its standard error and compare the resulting z statistic with a critical value from the standard normal distribution. Confidence limits for the indirect effect are also typically based on critical values from the standard normal distribution. This article uses a simulation study to demonstrate that confidence limits are imbalanced because the distribution of the indirect effect is normal only in special cases. Two alternatives for improving the performance of confidence limits for the indirect effect are evaluated: (a) a method based on the distribution of the product of two normal random variables, and (b) resampling methods. In Study 1, confidence limits based on the distribution of the product are more accurate than methods based on an assumed normal distribution but confidence limits are still imbalanced. Study 2 demonstrates that more accurate confidence limits are obtained using resampling methods, with the bias-corrected bootstrap the best method overall. PMID:20157642

Lattice cell diffusion coefficients. Definitions and comparisons

International Nuclear Information System (INIS)

Hughes, R.P.

1980-01-01

Definitions of equivalent diffusion coefficients for regular lattices of heterogeneous cells have been given by several authors. The paper begins by reviewing these different definitions and the unification of their derivation. This unification makes clear how accurately each definition (together with appropriate cross-section definitions to preserve the eigenvalue) represents the individual reaction rates within the cell. The approach can be extended to include asymmetric cells and whereas before, the buckling describing the macroscopic flux shape was real, here it is found to be complex. A neutron ''drift'' coefficient as well as a diffusion coefficient is necessary to produce the macroscopic flux shape. The numerical calculation of the various different diffusion coefficients requires the solutions of equations similar to the ordinary transport equation for an infinite lattice. Traditional reactor physics codes are not sufficiently flexible to solve these equations in general. However, calculations in certain simple cases are presented and the theoretical results quantified. In difficult geometries, Monte Carlo techniques can be used to calculate an effective diffusion coefficient. These methods relate to those already described provided that correlation effects between different generations of neutrons are included. Again, these effects are quantified in certain simple cases. (author)

Globalization of consumer confidence

Directory of Open Access Journals (Sweden)

Çelik Sadullah

2017-01-01

Full Text Available The globalization of world economies and the importance of nowcasting analysis have been at the core of the recent literature. Nevertheless, these two strands of research are hardly coupled. This study aims to fill this gap through examining the globalization of the consumer confidence index (CCI by applying conventional and unconventional econometric methods. The US CCI is used as the benchmark in tests of comovement among the CCIs of several developing and developed countries, with the data sets divided into three sub-periods: global liquidity abundance, the Great Recession, and postcrisis. The existence and/or degree of globalization of the CCIs vary according to the period, whereas globalization in the form of coherence and similar paths is observed only during the Great Recession and, surprisingly, stronger in developing/emerging countries.

Pediatrics Residents' Confidence and Performance Following a Longitudinal Quality Improvement Curriculum.

Science.gov (United States)

Courtlandt, Cheryl; Noonan, Laura; Koricke, Maureen Walsh; Zeskind, Philip Sanford; Mabus, Sarah; Feld, Leonard

2016-02-01

Quality improvement (QI) training is an integral part of residents' education. Understanding the educational value of a QI curriculum facilitates understanding of its impact. The purpose of this study was to evaluate the effects of a longitudinal QI curriculum on pediatrics residents' confidence and competence in the acquisition and application of QI knowledge and skills. Three successive cohorts of pediatrics residents (N = 36) participated in a longitudinal curriculum designed to increase resident confidence in QI knowledge and skills. Key components were a succession of progressive experiential projects, QI coaching, and resident team membership culminating in leadership of the project. Residents completed precurricular and postcurricular surveys and demonstrated QI competence by performance on the pediatric QI assessment scenario. Residents participating in the Center for Advancing Pediatric Excellence QI curriculum showed significant increases in pre-post measures of confidence in QI knowledge and skills. Coaching and team leadership were ranked by resident participants as having the most educational value among curriculum components. A pediatric QI assessment scenario, which correlated with resident-perceived confidence in acquisition of QI skills but not QI knowledge, is a tool available to test pediatrics residents' QI knowledge. A 3-year longitudinal, multimodal, experiential QI curriculum increased pediatrics residents' confidence in QI knowledge and skills, was feasible with faculty support, and was well-accepted by residents.

Heat transfer coefficient of cryotop during freezing.

Science.gov (United States)

Li, W J; Zhou, X L; Wang, H S; Liu, B L; Dai, J J

2013-01-01

Cryotop is an efficient vitrification method for cryopreservation of oocytes. It has been widely used owing to its simple operation and high freezing rate. Recently, the heat transfer performance of cryotop was studied by numerical simulation in several studies. However, the range of heat transfer coefficient in the simulation is uncertain. In this study, the heat transfer coefficient for cryotop during freezing process was analyzed. The cooling rates of 40 percent ethylene glycol (EG) droplet in cryotop during freezing were measured by ultra-fast measurement system and calculated by numerical simulation at different value of heat transfer coefficient. Compared with the results obtained by two methods, the range of the heat transfer coefficient necessary for the numerical simulation of cryotop was determined, which is between 9000 W/(m(2)·K) and 10000 W/(m (2)·K).

Estimation and interpretation of keff confidence intervals in MCNP

International Nuclear Information System (INIS)

Urbatsch, T.J.

1995-11-01

MCNP's criticality methodology and some basic statistics are reviewed. Confidence intervals are discussed, as well as how to build them and their importance in the presentation of a Monte Carlo result. The combination of MCNP's three k eff estimators is shown, theoretically and empirically, by statistical studies and examples, to be the best k eff estimator. The method of combining estimators is based on a solid theoretical foundation, namely, the Gauss-Markov Theorem in regard to the least squares method. The confidence intervals of the combined estimator are also shown to have correct coverage rates for the examples considered

Confidence limits for small numbers of events in astrophysical data

Science.gov (United States)

Gehrels, N.

1986-01-01

The calculation of limits for small numbers of astronomical counts is based on standard equations derived from Poisson and binomial statistics; although the equations are straightforward, their direct use is cumbersome and involves both table-interpolations and several mathematical operations. Convenient tables and approximate formulae are here presented for confidence limits which are based on such Poisson and binomial statistics. The limits in the tables are given for all confidence levels commonly used in astrophysics.

Learning style and confidence: an empirical investigation of Japanese employees

OpenAIRE

Yoshitaka Yamazaki

2012-01-01

This study aims to examine how learning styles relate to employees' confidence through a view of Kolb's experiential learning theory. For this aim, an empirical investigation was conducted using the sample of 201 Japanese employees who work for a Japanese multinational corporation. Results illustrated that the learning style group of acting orientation described a significantly higher level of job confidence than that of reflecting orientation, whereas the two groups of feeling and thinking o...

PET attenuation coefficients from CT images: experimental evaluation of the transformation of CT into PET 511-keV attenuation coefficients.

Science.gov (United States)

Burger, C; Goerres, G; Schoenes, S; Buck, A; Lonn, A H R; Von Schulthess, G K

2002-07-01

The CT data acquired in combined PET/CT studies provide a fast and essentially noiseless source for the correction of photon attenuation in PET emission data. To this end, the CT values relating to attenuation of photons in the range of 40-140 keV must be transformed into linear attenuation coefficients at the PET energy of 511 keV. As attenuation depends on photon energy and the absorbing material, an accurate theoretical relation cannot be devised. The transformation implemented in the Discovery LS PET/CT scanner (GE Medical Systems, Milwaukee, Wis.) uses a bilinear function based on the attenuation of water and cortical bone at the CT and PET energies. The purpose of this study was to compare this transformation with experimental CT values and corresponding PET attenuation coefficients. In 14 patients, quantitative PET attenuation maps were calculated from germanium-68 transmission scans, and resolution-matched CT images were generated. A total of 114 volumes of interest were defined and the average PET attenuation coefficients and CT values measured. From the CT values the predicted PET attenuation coefficients were calculated using the bilinear transformation. When the transformation was based on the narrow-beam attenuation coefficient of water at 511 keV (0.096 cm(-1)), the predicted attenuation coefficients were higher in soft tissue than the measured values. This bias was reduced by replacing 0.096 cm(-1) in the transformation by the linear attenuation coefficient of 0.093 cm(-1) obtained from germanium-68 transmission scans. An analysis of the corrected emission activities shows that the resulting transformation is essentially equivalent to the transmission-based attenuation correction for human tissue. For non-human material, however, it may assign inaccurate attenuation coefficients which will also affect the correction in neighbouring tissue.

Soccer ball lift coefficients via trajectory analysis

International Nuclear Information System (INIS)

Goff, John Eric; Carre, Matt J

2010-01-01

We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin parameters that have not been obtained by today's wind tunnels. Our trajectory analysis technique is not only a valuable tool for professional sports scientists, it is also accessible to students with a background in undergraduate-level classical mechanics.

Soccer ball lift coefficients via trajectory analysis

Energy Technology Data Exchange (ETDEWEB)

Goff, John Eric [Department of Physics, Lynchburg College, Lynchburg, VA 24501 (United States); Carre, Matt J, E-mail: goff@lynchburg.ed [Department of Mechanical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)

2010-07-15

We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin parameters that have not been obtained by today's wind tunnels. Our trajectory analysis technique is not only a valuable tool for professional sports scientists, it is also accessible to students with a background in undergraduate-level classical mechanics.

Factorization of Transport Coefficients in Macroporous Media

DEFF Research Database (Denmark)

Shapiro, Alexander; Stenby, Erling Halfdan

2000-01-01

We prove the fundamental theorem about factorization of the phenomenological coefficients for transport in macroporous media. By factorization we mean the representation of the transport coefficients as products of geometric parameters of the porous medium and the parameters characteristic...

Evaluating Measures of Optimism and Sport Confidence

Science.gov (United States)

Fogarty, Gerard J.; Perera, Harsha N.; Furst, Andrea J.; Thomas, Patrick R.

2016-01-01

The psychometric properties of the Life Orientation Test-Revised (LOT-R), the Sport Confidence Inventory (SCI), and the Carolina SCI (CSCI) were examined in a study involving 260 athletes. The study aimed to test the dimensional structure, convergent and divergent validity, and invariance over competition level of scores generated by these…

Current Developments in Measuring Academic Behavioural Confidence

Science.gov (United States)

Sander, Paul

2009-01-01

Using published findings and by further analyses of existing data, the structure, validity and utility of the Academic Behavioural Confidence scale (ABC) is critically considered. Validity is primarily assessed through the scale's relationship with other existing scales as well as by looking for predicted differences. The utility of the ABC scale…

Monte Carlo based diffusion coefficients for LMFBR analysis

International Nuclear Information System (INIS)

Van Rooijen, Willem F.G.; Takeda, Toshikazu; Hazama, Taira

2010-01-01

A method based on Monte Carlo calculations is developed to estimate the diffusion coefficient of unit cells. The method uses a geometrical model similar to that used in lattice theory, but does not use the assumption of a separable fundamental mode used in lattice theory. The method uses standard Monte Carlo flux and current tallies, and the continuous energy Monte Carlo code MVP was used without modifications. Four models are presented to derive the diffusion coefficient from tally results of flux and partial currents. In this paper the method is applied to the calculation of a plate cell of the fast-spectrum critical facility ZEBRA. Conventional calculations of the diffusion coefficient diverge in the presence of planar voids in the lattice, but our Monte Carlo method can treat this situation without any problem. The Monte Carlo method was used to investigate the influence of geometrical modeling as well as the directional dependence of the diffusion coefficient. The method can be used to estimate the diffusion coefficient of complicated unit cells, the limitation being the capabilities of the Monte Carlo code. The method will be used in the future to confirm results for the diffusion coefficient obtained of the Monte Carlo code. The method will be used in the future to confirm results for the diffusion coefficient obtained with deterministic codes. (author)

Torsion method for measuring piezooptic coefficients

Energy Technology Data Exchange (ETDEWEB)

Skab, I.; Smaga, I.; Savaryn, V.; Vasylkiv, Yu.; Vlokh, R. [Institute of Physical Optics, Lviv (Ukraine)

2011-01-15

We develop and describe analytically a torsion method for measuring piezooptic coefficients associated with shear stresses. It is shown that the method enables to increase significantly the accuracy of determination of piezooptic coefficients. The method and the appropriate apparatus are verified experimentally on the example of LiNbO{sub 3} crystals. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Understanding Confidence Intervals With Visual Representations

OpenAIRE

Navruz, Bilgin; Delen, Erhan

2014-01-01

In the present paper, we showed how confidence intervals (CIs) are valuable and useful in research studies when they are used in the correct form with correct interpretations. The sixth edition of the APA (2010) Publication Manual strongly recommended reporting CIs in research studies, and it was described as “the best reporting strategy” (p. 34). Misconceptions and correct interpretations of CIs were presented from several textbooks. In addition, limitations of the null hypothesis statistica...

Transfer coefficients for terrestrial foodchain: their derivation and limitations

International Nuclear Information System (INIS)

Ng, Y.C.; Colsher, C.S.; Thompson, S.E.

1979-01-01

Transfer coefficients to predict the passage of isotopes from the environment to terrestrial foods have been derived for various radionuclides of importance in the nuclear fuel cycle. These data update and extend previously recommended handbook values. We derive transfer coefficients to terrestrial foods and describe the systematics of the derived transfer coefficients. Suggestions are offered for changes in the values of transfer coefficients to terrestrial foods that now appear in federal regulatory guides. Deficiencies in our present knowledge concerning transfer coefficients and limitations in the use of these values to ensure compliance with radiation protection standards are discussed

Ideal related K-theory with coefficients

DEFF Research Database (Denmark)

Eilers, Soren; Restorff, Gunnar; Ruiz, Efren

2017-01-01

In this paper, we define an invariant, which we believe should be the substitute for total K-theory in the case when there is one distinguished ideal. Moreover, some diagrams relating the new groups to the ordinary K-groups with coefficients are constructed. These diagrams will in most cases help...... to determine the new groups, and will in a companion paper be used to prove a universal multi-coefficient theorem for the one distinguished ideal case for a large class of algebras......In this paper, we define an invariant, which we believe should be the substitute for total K-theory in the case when there is one distinguished ideal. Moreover, some diagrams relating the new groups to the ordinary K-groups with coefficients are constructed. These diagrams will in most cases help...

Confidence Testing for Knowledge-Based Global Communities

Science.gov (United States)

Jack, Brady Michael; Liu, Chia-Ju; Chiu, Houn-Lin; Shymansky, James A.

2009-01-01

This proposal advocates the position that the use of confidence wagering (CW) during testing can predict the accuracy of a student's test answer selection during between-subject assessments. Data revealed female students were more favorable to taking risks when making CW and less inclined toward risk aversion than their male counterparts. Student…

Resummed coefficient function for the shape function

OpenAIRE

Aglietti, U.

2001-01-01

We present a leading evaluation of the resummed coefficient function for the shape function. It is also shown that the coefficient function is short-distance-dominated. Our results allow relating the shape function computed on the lattice to the physical QCD distributions.

Alternatives to Pearson's and Spearman's Correlation Coefficients

OpenAIRE

Smarandache, Florentin

2008-01-01

This article presents several alternatives to Pearson's correlation coefficient and many examples. In the samples where the rank in a discrete variable counts more than the variable values, the mixtures that we propose of Pearson's and Spearman's correlation coefficients give better results.

Coefficients of tracer transfer through membranes. Pt. 7

Energy Technology Data Exchange (ETDEWEB)

Dorabialska, A; Hawlicka, E; Plonka, A [Politechnika Lodzka (Poland)

1974-01-01

The doubled value of the tracer transfer coefficient in the self-diffusion process is equal to the sum of tracer transfer coefficients in the diffusion and interfusion processes. The fundamental phenomenological relation can be deduced for the coefficients of tracer transfer between two phases of electrolyte solutions spearated by a virtual boundary. Indeed, the doubled value of the tracer mobility in the self-diffusion experiment (no concentration gradient of the traced substance) is equal to the sum of the tracer mobilities in the diffusion (tracer movement along with the concentration gradient of the traced substance) and interfusion experiments (tracer movement against the concentration gradient of the traced substance). Thus the doubled value of the tracer transfer coefficient in the self-diffusion process should be equal to the sum of tracer transfer coefficients in the diffusion and interfusion processes. The experimental verification of that fundamental relation is presented.

Planning an Availability Demonstration Test with Consideration of Confidence Level

Directory of Open Access Journals (Sweden)

Frank Müller

2017-08-01

Full Text Available The full service life of a technical product or system is usually not completed after an initial failure. With appropriate measures, the system can be returned to a functional state. Availability is an important parameter for evaluating such repairable systems: Failure and repair behaviors are required to determine this availability. These data are usually given as mean value distributions with a certain confidence level. Consequently, the availability value also needs to be expressed with a confidence level. This paper first highlights the bootstrap Monte Carlo simulation (BMCS for availability demonstration and inference with confidence intervals based on limited failure and repair data. The BMCS enables point-, steady-state and average availability to be determined with a confidence level based on the pure samples or mean value distributions in combination with the corresponding sample size of failure and repair behavior. Furthermore, the method enables individual sample sizes to be used. A sample calculation of a system with Weibull-distributed failure behavior and a sample of repair times is presented. Based on the BMCS, an extended, new procedure is introduced: the “inverse bootstrap Monte Carlo simulation” (IBMCS to be used for availability demonstration tests with consideration of confidence levels. The IBMCS provides a test plan comprising the required number of failures and repair actions that must be observed to demonstrate a certain availability value. The concept can be applied to each type of availability and can also be applied to the pure samples or distribution functions of failure and repair behavior. It does not require special types of distribution. In other words, for example, a Weibull, a lognormal or an exponential distribution can all be considered as distribution functions of failure and repair behavior. After presenting the IBMCS, a sample calculation will be carried out and the potential of the BMCS and the IBMCS

Algebraic polynomials with random coefficients

Directory of Open Access Journals (Sweden)

K. Farahmand

2002-01-01

Full Text Available This paper provides an asymptotic value for the mathematical expected number of points of inflections of a random polynomial of the form a0(ω+a1(ω(n11/2x+a2(ω(n21/2x2+…an(ω(nn1/2xn when n is large. The coefficients {aj(w}j=0n, w∈Ω are assumed to be a sequence of independent normally distributed random variables with means zero and variance one, each defined on a fixed probability space (A,Ω,Pr. A special case of dependent coefficients is also studied.

Estimating varying coefficients for partial differential equation models.

Science.gov (United States)

Zhang, Xinyu; Cao, Jiguo; Carroll, Raymond J

2017-09-01

Partial differential equations (PDEs) are used to model complex dynamical systems in multiple dimensions, and their parameters often have important scientific interpretations. In some applications, PDE parameters are not constant but can change depending on the values of covariates, a feature that we call varying coefficients. We propose a parameter cascading method to estimate varying coefficients in PDE models from noisy data. Our estimates of the varying coefficients are shown to be consistent and asymptotically normally distributed. The performance of our method is evaluated by a simulation study and by an empirical study estimating three varying coefficients in a PDE model arising from LIDAR data. © 2017, The International Biometric Society.

Using ab initio 'data' to accurately determine the fourth density virial coefficient of helium

International Nuclear Information System (INIS)

Moldover, Michael R.; McLinden, Mark O.

2010-01-01

We combine accurate ab initio calculations of the second and third density virial coefficients, B(T) and C(T), of 4 He with measurements of its (p-ρ-T) behavior to determine the fourth density virial coefficient D(T). The measurements were made with a two-sinker, magnetic-suspension densimeter at pressures up to 38 MPa. The measurements on isotherms from T = 223 K to T = 323 K were previously published; new measurements from T = 323 K to T = 500 K are presented here. On each isotherm, a regression of the virial expansion was constrained to the ab initio values of B(T) and C(T); the regression determined D(T) as well as two apparatus-dependent parameters that compensated for systematic errors in the measurements. The percentage uncertainties of D(T) ranged from 2.6% at T = 223 K to 9.5% at T = 400 K to 24.7% at T = 500 K, where these uncertainties are expanded uncertainties with coverage factor of k = 2 corresponding to a 95% confidence interval. These uncertainties are 1/6th of the uncertainty obtained without the ab initio values of B(T) and C(T). The apparatus-dependent parameters can be used to calibrate the densimeter, and this will reduce the uncertainty of other measurements made with this two-sinker densimeter. The new values of D(T) will find applications in accurate gas metrology, such as a primary pressure standard based on the refractive index of helium.

Confidence-based learning CME: overcoming barriers in irritable bowel syndrome with constipation.

Science.gov (United States)

Cash, Brooks; Mitchner, Natasha A; Ravyn, Dana

2011-01-01

Performance of health care professionals depends on both medical knowledge and the certainty with which they possess it. Conventional continuing medical education interventions assess the correctness of learners' responses but do not determine the degree of confidence with which they hold incorrect information. This study describes the use of confidence-based learning (CBL) in an activity designed to enhance learners' knowledge, confidence in their knowledge, and clinical competence with regard to constipation-predominant IBS (IBS-C), a frequently underdiagnosed and misdiagnosed condition. The online CBL activity included multiple-choice questions in 2 modules: Burden of Care (BOC; 28 questions) and Patient Scenarios (PS; 9 case-based questions). After formative assessment, targeted feedback was provided, and the learner focused on material with demonstrated knowledge and/or confidence gaps. The process was repeated until 85% of questions were answered correctly and confidently (ie, mastery was attained). Of 275 participants (24% internal medicine, 13% gastroenterology, 32% family medicine, and 31% other), 249 and 167 completed the BOC and PS modules, respectively. Among all participants, 61.8% and 98.2% achieved mastery in the BOC and PS modules, respectively. Baseline mastery levels between specialties were significantly different in the BOC module (p = 0.002); no significant differences were evident between specialties in final mastery levels. Approximately one-third of learners were confident and wrong in topics of epidemiology, defining IBS and constipation, and treatments in the first iteration. No significant difference was observed between specialties for the PS module in either the first or last iterations. Learners achieved mastery in topics pertaining to IBS-C regardless of baseline knowledge or specialty. These data indicate that CME activities employing CBL can be used to address knowledge and confidence gaps. Copyright © 2010 The Alliance for

Clebsch-Gordan and Racah coefficients of SUpq(2)

International Nuclear Information System (INIS)

Kachurik, I.I.

1993-01-01

Explicit expressions for the Clebsch-Gordan coefficients and for the Racah coefficients of the two-parametric quantum algebra SU pq (2) are derived. They are given as finite sums and as terminating basic hypergeometric functions 3 φ 2 and 4 φ 3 . It is indicated how other expressions for these coefficients can be derived with the help of basic hypergeometric functions. (author). 11 refs

On some properties of SU(3 fusion coefficients

Directory of Open Access Journals (Sweden)

Robert Coquereaux

2016-11-01

Full Text Available Three aspects of the SU(3 fusion coefficients are revisited: the generating polynomials of fusion coefficients are written explicitly; some curious identities generalizing the classical Freudenthal–de Vries formula are derived; and the properties of the fusion coefficients under conjugation of one of the factors, previously analyzed in the classical case, are extended to the affine algebra suˆ(3 at finite level.

Variable-coefficient higher-order nonlinear Schroedinger model in optical fibers: Variable-coefficient bilinear form, Baecklund transformation, brightons and symbolic computation

International Nuclear Information System (INIS)

Tian Bo; Gao Yitian; Zhu Hongwu

2007-01-01

Symbolically investigated in this Letter is a variable-coefficient higher-order nonlinear Schroedinger (vcHNLS) model for ultrafast signal-routing, fiber laser systems and optical communication systems with distributed dispersion and nonlinearity management. Of physical and optical interests, with bilinear method extend, the vcHNLS model is transformed into a variable-coefficient bilinear form, and then an auto-Baecklund transformation is constructed. Constraints on coefficient functions are analyzed. Potentially observable with future optical-fiber experiments, variable-coefficient brightons are illustrated. Relevant properties and features are discussed as well. Baecklund transformation and other results of this Letter will be of certain value to the studies on inhomogeneous fiber media, core of dispersion-managed brightons, fiber amplifiers, laser systems and optical communication links with distributed dispersion and nonlinearity management

Micro- and macroscale coefficients of friction of cementitious materials

International Nuclear Information System (INIS)

Lomboy, Gilson; Sundararajan, Sriram; Wang, Kejin

2013-01-01

Millions of metric tons of cementitious materials are produced, transported and used in construction each year. The ease or difficulty of handling cementitious materials is greatly influenced by the material friction properties. In the present study, the coefficients of friction of cementitious materials were measured at the microscale and macroscale. The materials tested were commercially-available Portland cement, Class C fly ash, and ground granulated blast furnace slag. At the microscale, the coefficient of friction was determined from the interaction forces between cementitious particles using an Atomic Force Microscope. At the macroscale, the coefficient of friction was determined from stresses on bulk cementitious materials under direct shear. The study indicated that the microscale coefficient of friction ranged from 0.020 to 0.059, and the macroscale coefficient of friction ranged from 0.56 to 0.75. The fly ash studied had the highest microscale coefficient of friction and the lowest macroscale coefficient of friction. -- Highlights: •Microscale (interparticle) coefficient of friction (COF) was determined with AFM. •Macroscale (bulk) COF was measured under direct shear. •Fly ash had the highest microscale COF and the lowest macroscale COF. •Portland cement against GGBFS had the lowest microscale COF. •Portland cement against Portland cement had the highest macroscale COF

Re-thinking accountability: trust versus confidence in medical practice.

Science.gov (United States)

Checkland, K; Marshall, M; Harrison, S

2004-04-01

In seeking to prevent a reoccurrence of scandals such as that involving cardiac surgery in Bristol, the UK government has adopted a model of regulation that uses rules and surveillance as a way of both improving the quality of care delivered and increasing confidence in healthcare institutions. However, this approach may actually act to reduce confidence and trust while also reducing the moral motivation of practitioners. Accountability in health care is discussed, and it is suggested that openness about the difficult dilemmas that arise when practitioners have a duty to be accountable to more than one audience may be an alternative means of restoring trust. A greater emphasis on the sharing of information between individual health professionals and their patients would increase trust and would allow patients to hold their doctors to account for the quality of care they receive. Concentrating more on developing trust by the sharing of information and less on the futile search for complete confidence in systems and rules may improve the quality of care delivered while also nurturing the moral motivation of professionals upon which the delivery of high quality health care depends.

Heat transfer coefficient for boiling carbon dioxide

DEFF Research Database (Denmark)

Knudsen, Hans Jørgen Høgaard; Jensen, Per Henrik

1998-01-01

Heat transfer coefficient and pressure drop for boiling carbon dioxide (R744) flowing in a horizontal pipe has been measured. The calculated heat transfer coeeficient has been compared with the Chart correlation of Shah. The Chart Correlation predits too low heat transfer coefficient but the ratio...... between the measured and the calculated heat transfer coefficient is nearly constant and equal 1.9. With this factor the correlation predicts the measured data within 14% (RMS). The pressure drop is of the same order as the measuring uncertainty and the pressure drop has not been compared with correlation's....

Post choice information integration as a causal determinant of confidence: Novel data and a computational account.

Science.gov (United States)

Moran, Rani; Teodorescu, Andrei R; Usher, Marius

2015-05-01

Confidence judgments are pivotal in the performance of daily tasks and in many domains of scientific research including the behavioral sciences, psychology and neuroscience. Positive resolution i.e., the positive correlation between choice-correctness and choice-confidence is a critical property of confidence judgments, which justifies their ubiquity. In the current paper, we study the mechanism underlying confidence judgments and their resolution by investigating the source of the inputs for the confidence-calculation. We focus on the intriguing debate between two families of confidence theories. According to single stage theories, confidence is based on the same information that underlies the decision (or on some other aspect of the decision process), whereas according to dual stage theories, confidence is affected by novel information that is collected after the decision was made. In three experiments, we support the case for dual stage theories by showing that post-choice perceptual availability manipulations exert a causal effect on confidence-resolution in the decision followed by confidence paradigm. These finding establish the role of RT2, the duration of the post-choice information-integration stage, as a prime dependent variable that theories of confidence should account for. We then present a novel list of robust empirical patterns ('hurdles') involving RT2 to guide further theorizing about confidence judgments. Finally, we present a unified computational dual stage model for choice, confidence and their latencies namely, the collapsing confidence boundary model (CCB). According to CCB, a diffusion-process choice is followed by a second evidence-integration stage towards a stochastic collapsing confidence boundary. Despite its simplicity, CCB clears the entire list of hurdles. Copyright © 2015 Elsevier Inc. All rights reserved.

The P Value Problem in Otolaryngology: Shifting to Effect Sizes and Confidence Intervals.

Science.gov (United States)

Vila, Peter M; Townsend, Melanie Elizabeth; Bhatt, Neel K; Kao, W Katherine; Sinha, Parul; Neely, J Gail

2017-06-01

There is a lack of reporting effect sizes and confidence intervals in the current biomedical literature. The objective of this article is to present a discussion of the recent paradigm shift encouraging the use of reporting effect sizes and confidence intervals. Although P values help to inform us about whether an effect exists due to chance, effect sizes inform us about the magnitude of the effect (clinical significance), and confidence intervals inform us about the range of plausible estimates for the general population mean (precision). Reporting effect sizes and confidence intervals is a necessary addition to the biomedical literature, and these concepts are reviewed in this article.

Expanding Horizons--Into the Future with Confidence!

Science.gov (United States)

Volk, Valerie

2006-01-01

Gifted students often show a deep interest in and profound concern for the complex issues of society. Given the leadership potential of these students and their likely responsibility for solving future social problems, they need to develop this awareness and also a sense of confidence in dealing with future issues. The Future Problem Solving…

Two sides of the same coin : Monetary incentives concurrently improve and bias confidence judgments

NARCIS (Netherlands)

Lebreton, Maël; Langdon, Shari; Slieker, Matthijs J; Nooitgedacht, Jip S; Goudriaan, Anna E; Denys, D.; van Holst, Ruth J; Luigjes, Judy

2018-01-01

Decisions are accompanied by a feeling of confidence, that is, a belief about the decision being correct. Confidence accuracy is critical, notably in high-stakes situations such as medical or financial decision-making. We investigated how incentive motivation influences confidence accuracy by

Linking employee confidence to performance: a study of self-managing service teams

NARCIS (Netherlands)

Jong, de A.; Ruyter, de J.C.; Wetzels, M.G.M.

2006-01-01

The increasing implementation of self-managing teams (SMTs) in service delivery suggests the importance of developing confidence beliefs about a team's collective competence. This research examined causality in the linkage between employee confidence beliefs and performance for boundary-spanning

CERN confident of LHC start-up in 2007

CERN Document Server

2007-01-01

"Delegates attending the 140th meeting of CERN Council heard a confident report from the Laboratory about the scheduled start-up of the world's highest energy particle accelerator, the Large Hadron Collier (LHC), in 2007." (1 page)

Older widows and married women: their intimates and confidants.

Science.gov (United States)

Babchuk, N; Anderson, T B

1989-01-01

Interview data obtained from 132 women sixty-five and older reveals that the widows and married women have a comparable number of primary friends. Being over age seventy-four influences the size of the friendship network for widows but not married women. The primary friendships of widows and married women parallel each other in terms of endurance and stability. Primary ties with men are the exception rather than the norm, for both widows and married women. Widows do differ from married women in that the former rely on confidant friends to a greater extent. Ties between older women and their confidants are characterized by norms of reciprocity.

Social media sentiment and consumer confidence

OpenAIRE

Daas, Piet J.H.; Puts, Marco J.H.

2014-01-01

Changes in the sentiment of Dutch public social media messages were compared with changes in monthly consumer confidence over a period of three-and-a-half years, revealing that both were highly correlated (up to r = 0.9) and that both series cointegrated. This phenomenon is predominantly affected by changes in the sentiment of all Dutch public Facebook messages. The inclusion of various selections of public Twitter messages improved this association and the response to changes in sentiment. G...

Teachers' confidence in teaching HIV/AIDS and sexuality in South African and Tanzanian schools.

Science.gov (United States)

Helleve, Arnfinn; Flisher, Alan J; Onya, Hans; Kaaya, Sylvia; Mukoma, Wanjiru; Swai, Caroline; Klepp, Knut-Inge

2009-06-01

This study aimed to investigate how confident and comfortable teachers at Tanzanian and South African urban and rural schools are in teaching HIV/AIDS and sexuality. It also aimed at identifying factors associated with teacher confidence and investigated how reported confidence was associated with the implementation of educational programmes on HIV/AIDS and sexuality. A survey was conducted among South African grade 8 and 9 Life Orientation teachers, and among science teachers for grade 5 to 7 in public primary schools in Tanzania. Teachers' confidence levels were measured on a four-item scale (0-3). A total number of 266 teachers participated in a survey in 86 schools in South Africa and Tanzania. Overall, teachers report to be rather confident in teaching HIV/AIDS and sexuality. Tanzanian teachers reported higher levels of confidence then did their South Africa colleagues (2.1 vs. 1.8; p teaching was significantly associated with the numbers of years teaching HIV/AIDS and sexuality, formal training in these subjects, experience in discussing the topics with others, school policy and priority given to teaching HIV/AIDS and sexuality at school. Finally, confidence in teaching remained positively associated with self-reported successful implementation of school-based programmes after adjusting for gender, age, religion and numbers of years teaching HIV/AIDS and sexuality. Across urban and rural sites in South Africa and Tanzania teachers reported to be fairly confident in teaching HIV/AIDS and sexuality. Further strengthening of their confidence levels could, however, be an important measure for improving the implementation of such programmes.

Power coefficient anomaly in Joyo, (2)

International Nuclear Information System (INIS)

Ishikawa, Makoto; Yamashita, Yoshioki; Sasaki, Makoto; Nara, Yoshihiko.

1981-12-01

In this report, the presumption about the mechanism having caused the power coefficient anomaly in Joyo during the 75 MW power-raising test in 1979 is described. After the previous report, the new information about the results of the post-irradiation examination and the analysis of the power coefficient of Joyo were able to be obtained. From these information, the mechanism of causing the anomaly was presumed as follows. In 50 MW operation, the fuel burnup reached about 10,000 MWD/ton at the end of second cycle, and produced fission gas was almost retained in fuel pellets. When the power was raised from 50 MW to 75 MW for the first time, the fission gas began to be released when 50 MW was somewhat exceeded. The fission gas release caused the temperature rise and cracking of fuel pellets, and elongated fuel stack length abruptly. These phenomena induced to enlarge the fuel expansion reactivity effect and Doppler reactivity effect, and caused the anomalous behavior of power coefficient. After reaching 75 MW, the fuel stack length did not respond normally to reactor power change, and the magnitude of power coefficient became smaller. The reactivity was lost considerably from the core after the anomaly. (Kako, I.)

Transport Coefficients for dense hard-disk systems

NARCIS (Netherlands)

Garcia-Rojo, R.; Luding, Stefan; Brey, J. Javier; Ooms, G.; Hoogendoorn, C.J.

2007-01-01

A study of the transport coefficients of a system of elastic hard disks, based on the use of Helfand-Einstein expressions is reported. The pressure, the viscosity, and the heat conductivity are examined for different density and system-size. While most transport coefficients agree with Enskog theory

What does confidence mean to people who have had a stroke? A qualitative interview study.

Science.gov (United States)

Horne, Jane; Lincoln, Nadina Berrice; Preston, Jenny; Logan, Pip

2014-11-01

To explore the meaning of confidence to stroke patients after stroke in order to inform the development of a measurement tool. Qualitative interview study using interpretative phenomenological analysis (IPA). Ten stroke survivors were purposively selected from those participating in a multi-centre randomised trial of outdoor mobility rehabilitation. Interviews about confidence were conducted in participants' homes, audio recorded and transcribed verbatim. Six themes emerged from the analysis. These were loss of identity, fear, social confidence, role confidence, mastering skill and attitudes and beliefs. Loss of identity was particularly evident in the early stages of stroke recovery. Fear was a barrier to regaining confidence and was associated with avoidance behaviours. Lack of social confidence was a common problem which appeared difficult to resolve. Life roles motivated participants to re-engage in daily life activities. Personal attitudes and beliefs, combined with the attitudes of significant others, contributed to personal feelings of competence. This study provides a coherent definition of the meaning of confidence through the experiences of stroke survivors. Being successful in gradually re-engaging in activities, including social activities and life roles helped to establish a positive self-belief. The influence of others, such as family and friends reinforce self-beliefs. Confidence and self-efficacy appear to be a similar construct. However, participants in this study also identified a relationship between confidence and self-esteem. The findings indicate that all six themes need to be included in a confidence measure to encompass the meaning of confidence as described by participants with stroke. © The Author(s) 2014.

Riesz frames and approximation of the frame coefficients

DEFF Research Database (Denmark)

Casazza, P.; Christensen, Ole

1998-01-01

A frame is a fmaily {f i } i=1 ∞ of elements in a Hilbert space with the property that every element in can be written as a (infinite) linear combination of the frame elements. Frame theory describes how one can choose the corresponding coefficients, which are called frame coefficients. From...... the mathematical point of view this is gratifying, but for applications it is a problem that the calculation requires inversion of an operator on . The projection method is introduced in order to avoid this problem. The basic idea is to consider finite subfamilies {f i } i=1 n of the frame and the orthogonal...... projection Pn onto its span. For has a representation as a linear combination of fi, i=1,2,..., n and the corresponding coefficients can be calculated using finite dimensional methods. We find conditions implying that those coefficients converge to the correct frame coefficients as n→∞, in which case we have...

Regional water coefficients for U.S. industrial sectors

Directory of Open Access Journals (Sweden)

Riccardo Boero

2017-12-01

Full Text Available Designing policies for water systems management requires the capability to assess the economic impacts of water availability and to effectively couple water withdrawals by human activities with natural hydrologic dynamics. At the core of any scientific approach to these issues there is the estimation of water withdrawals by industrial sectors in the form of water coefficients, which are measurements of the quantity of water withdrawn per dollar of GDP or output. In this work we focus on the contiguous United States and on the estimation of water coefficients for regional scale analyses. We first compare an established methodology for the estimation of national water coefficients with a parametric one we propose. Second, we introduce a method to estimate water coefficients at the level of ecological regions and we discuss how they reduce possible biases in regional analyses of water systems. We conclude discussing advantages and limits of regional water coefficients.

On finding algebraic expressions for genealogical coefficients

International Nuclear Information System (INIS)

Kanyauskas, J.M.; Shimonis, V.Ch.; Rudzikas, Z.B.

1979-01-01

It has been attempted to obtain analytical expressions for genealogical coefficients with one detached electron in the case of L-S coupling. A method of second quantization and tensorial properties of the quasi-spin operator are applied. It is restricted to the states for the classification of which the seigniority quantum number v is sufficient. Three ways of the acquirement of these expressions are discussed: 1. In the recurrent way wave functions of N and N-1 electrons are built, consequently expressing these functions in terms of the creation-annihilation operators. 2. Recurrent summation with the use of evident, simple genealogical coefficients. 3. Using the ratios, connecting the genealogical coefficients with the normalized multiplier. The data are presented in formulae and discussions. The generalization of the Redmond's formula is obtained and relatively simple algebraic expressions of the genealogical coefficients of the equivalent electron configurations, for the distinction of the recurrent terms of which introduction of the seigniority quantum number v is sufficient, are given

Rate coefficient for the reaction N + NO

Science.gov (United States)

Fox, J. L.

1994-01-01

Evidence has been advanced that the rate coefficient for the reaction N + NO right arrow N2 + O has a small positive temperature dependence at the high temperatures (900 to 1500 K) that prevail in the terrestrial middle and upper thermosphere by Siskind and Rusch (1992), and at the low temperatures (100 to 200 K) of the Martian lower thermosphere by Fox (1993). Assuming that the rate coefficient recommended by the Jet Propulsion Laboratory evaluation (DeMore et al., 1992) is accurate at 300 K, we derive here the low temperature value of the activation energy for this reaction and thus the rate coefficient that best fits the Viking 1 measured NO densities. We find that the fit is acceptable for a rate coefficient of about 1.3 x 10(exp -10)(T/300)(exp 0.5)exp(-400/T) and better for a value of about 2.5 x 10(exp -10)(T/300)(exp 0.5)exp(-600/T)cu cm/s.

Towards confidence in transport safety

International Nuclear Information System (INIS)

Robison, R.W.

1992-01-01

The U.S. Department of Energy (US DOE) plans to demonstrate to the public that high-level waste can be transported safely to the proposed repository. The author argues US DOE should begin now to demonstrate its commitment to safety by developing an extraordinary safety program for nuclear cargo it is now shipping. The program for current shipments should be developed with State, Tribal, and local officials. Social scientists should be involved in evaluating the effect of the safety program on public confidence. The safety program developed in cooperation with western states for shipments to the Waste Isolation Pilot plant is a good basis for designing that extraordinary safety program

Establishing and communicating confidence in the safety of deep geologic disposal. Approaches and arguments

International Nuclear Information System (INIS)

2002-01-01

Confidence among both technical experts and the public in the safety of deep geologic repositories for radioactive waste is a key element in the successful development of the repositories. This report presents the approaches and arguments that are currently used in OECD countries to establish and communicate confidence in their safety. It evaluates the state of the art for obtaining, presenting and demonstrating confidence in long-term safety, and makes recommendations on future directions and initiatives to be taken for improving confidence. (author)

False memories and memory confidence in borderline patients.

Science.gov (United States)

Schilling, Lisa; Wingenfeld, Katja; Spitzer, Carsten; Nagel, Matthias; Moritz, Steffen

2013-12-01

Mixed results have been obtained regarding memory in patients with borderline personality disorder (BPD). Prior reports and anecdotal evidence suggests that patients with BPD are prone to false memories but this assumption has to been put to firm empirical test, yet. Memory accuracy and confidence was assessed in 20 BPD patients and 22 healthy controls using a visual variant of the false memory (Deese-Roediger-McDermott) paradigm which involved a negative and a positive-valenced picture. Groups did not differ regarding veridical item recognition. Importantly, patients did not display more false memories than controls. At trend level, borderline patients rated more items as new with high confidence compared to healthy controls. The results tentatively suggest that borderline patients show uncompromised visual memory functions and display no increased susceptibility for distorted memories. Copyright © 2013 Elsevier Ltd. All rights reserved.

On Bayesian treatment of systematic uncertainties in confidence interval calculation

CERN Document Server

Tegenfeldt, Fredrik

2005-01-01

In high energy physics, a widely used method to treat systematic uncertainties in confidence interval calculations is based on combining a frequentist construction of confidence belts with a Bayesian treatment of systematic uncertainties. In this note we present a study of the coverage of this method for the standard Likelihood Ratio (aka Feldman & Cousins) construction for a Poisson process with known background and Gaussian or log-Normal distributed uncertainties in the background or signal efficiency. For uncertainties in the signal efficiency of upto 40 % we find over-coverage on the level of 2 to 4 % depending on the size of uncertainties and the region in signal space. Uncertainties in the background generally have smaller effect on the coverage. A considerable smoothing of the coverage curves is observed. A software package is presented which allows fast calculation of the confidence intervals for a variety of assumptions on shape and size of systematic uncertainties for different nuisance paramete...

The Binomial Coefficient for Negative Arguments

OpenAIRE

Kronenburg, M. J.

2011-01-01

The definition of the binomial coefficient in terms of gamma functions also allows non-integer arguments. For nonnegative integer arguments the gamma functions reduce to factorials, leading to the well-known Pascal triangle. Using a symmetry formula for the gamma function, this definition is extended to negative integer arguments, making the symmetry identity for binomial coefficients valid for all integer arguments. The agreement of this definition with some other identities and with the bin...

A study on effects of packaging characteristics on consumer's purchasing confidence

Directory of Open Access Journals (Sweden)

Naser Azad

2012-01-01

Full Text Available Packaging plays an important role on marketing products and services in many competitive environments. A good packaging can increase sales of products, reduces the level of inventory, which yields to higher profitability. In this paper, we study the relationship between a good packaging program and customer's confidence as well as customer's attraction on purchasing goods and services. The paper uses a questionnaire based on Likert scale and distributes among the target population of this survey and the information of packaging are divided into two groups of visibility and informative. The results indicate that a good and label with detailed and precise information on product could significantly impact customer's confidence while other visible information do not have much impact on customer's confidence.

Forecast Correlation Coefficient Matrix of Stock Returns in Portfolio Analysis

OpenAIRE

Zhao, Feng

2013-01-01

In Modern Portfolio Theory, the correlation coefficients decide the risk of a set of stocks in the portfolio. So, to understand the correlation coefficients between returns of stocks, is a challenge but is very important for the portfolio management. Usually, the stocks with small correlation coefficients or even negative correlation coefficients are preferred. One can calculate the correlation coefficients of stock returns based on the historical stock data. However, in order to control the ...

An analysis of confidence limit calculations used in AAPM Task Group No. 119

International Nuclear Information System (INIS)

Knill, Cory; Snyder, Michael

2011-01-01

Purpose: The report issued by AAPM Task Group No. 119 outlined a procedure for evaluating the effectiveness of IMRT commissioning. The procedure involves measuring gamma pass-rate indices for IMRT plans of standard phantoms and determining if the results fall within a confidence limit set by assuming normally distributed data. As stated in the TG report, the assumption of normally distributed gamma pass rates is a convenient approximation for commissioning purposes, but may not accurately describe the data. Here the authors attempt to better describe gamma pass-rate data by fitting it to different distributions. The authors then calculate updated confidence limits using those distributions and compare them to those derived using TG No. 119 method. Methods: Gamma pass-rate data from 111 head and neck patients are fitted using the TG No. 119 normal distribution, a truncated normal distribution, and a Weibull distribution. Confidence limits to 95% are calculated for each and compared. A more general analysis of the expected differences between the TG No. 119 method of determining confidence limits and a more time-consuming curve fitting method is performed. Results: The TG No. 119 standard normal distribution does not fit the measured data. However, due to the small range of measured data points, the inaccuracy of the fit has only a small effect on the final value of the confidence limits. The confidence limits for the 111 patient plans are within 0.1% of each other for all distributions. The maximum expected difference in confidence limits, calculated using TG No. 119's approximation and a truncated distribution, is 1.2%. Conclusions: A three-parameter Weibull probability distribution more accurately fits the clinical gamma index pass-rate data than the normal distribution adopted by TG No. 119. However, the sensitivity of the confidence limit on distribution fit is low outside of exceptional circumstances.

CERN confident of LHC start-up in 2007

CERN Document Server

Vanden Broeck, Renilde

2007-01-01

"Delegates attending the 140th meeting of CERN Council today heard a confident report from the Laboratory about the scheduled start-up of the world's highest energy particle accelerator, the Large Hadron Collier (LHC) in 2007. (1/2 page)

CERN confident of LHC start-up in 2007

CERN Multimedia

2006-01-01

"Delegates attending the 140th meeting of CERN Council today heard a confident report from the Laboratory about the scheduled start-up of the world's highest energy particle accelerator, the Large Hadron Collider (LHC) in 2007." (1/2 page)

Negative power coefficient on PHWRs with CARA fuel

International Nuclear Information System (INIS)

Lestani, H.A.; González, H.J.; Florido, P.C.

2014-01-01

Highlights: • A PHWR fuel was optimized to obtain a negative power coefficient. • Fuel cost, being a measure of design investment efficiency, was optimized. • Influence on power coefficient of geometrical and economical parameters’ was studied. • Different neutronic absorbers were studied; pure absorbers can be used. • Thermal and economical models were developed to complement neutronic assessment. - Abstract: A study of power coefficient of reactivity in heavy water reactors is made analyzing the reactivity components of fuels with several modifications oriented at reducing the coefficient. A cell model is used for neutronics calculations; a non-linear two dimensional model is used to evaluate the thermal changes that follow a power change; and a levelized unit energy cost model is used to assess the economical feasibility of the design changes introduced to reduce power coefficient. The necessity of modelling all the aforementioned quantities in a coupled scheme is stressed, as a strong interdependence was found. A series of design changes complied with a negative power coefficient of reactivity, with a feasible power radial distribution and with low refuelling cost. Some investigation lines that exceed the fuel cell study and deal with the plant operation are marked as potentially addressing the stable operation of big heavy water reactors

Concurrent predictors of dysfunctional parenting and maternal confidence: implications for parenting interventions.

Science.gov (United States)

Morawska, A; Sanders, M R

2007-11-01

The often intense nature of the conflict between parents and their toddlers requires better understanding of what happens during this stage of development and how difficulties can be prevented from escalating in the future. Clarification of the nature of family and parenting factors related to toddler behaviour allows better capacity for intervention development and tailoring to individual families. A total of 126 mothers of toddlers completed a self-report assessment battery, examining child behaviour, parenting style and confidence, as well as broader family adjustment measures. The study found that maternal confidence and dysfunctional parenting were interrelated and were also predicted best by parenting variables, in contrast to socio-demographic and child variables. Maternal confidence also mediated the relationships between family income and toddler behaviour. Parenting style and confidence are important modifiable factors to target in parenting interventions. The implications for the development, implementation and delivery of parenting interventions are discussed.

Minimum wall pressure coefficient of orifice plate energy dissipater

Directory of Open Access Journals (Sweden)

Wan-zheng Ai

2015-01-01

Full Text Available Orifice plate energy dissipaters have been successfully used in large-scale hydropower projects due to their simple structure, convenient construction procedure, and high energy dissipation ratio. The minimum wall pressure coefficient of an orifice plate can indirectly reflect its cavitation characteristics: the lower the minimum wall pressure coefficient is, the better the ability of the orifice plate to resist cavitation damage is. Thus, it is important to study the minimum wall pressure coefficient of the orifice plate. In this study, this coefficient and related parameters, such as the contraction ratio, defined as the ratio of the orifice plate diameter to the flood-discharging tunnel diameter; the relative thickness, defined as the ratio of the orifice plate thickness to the tunnel diameter; and the Reynolds number of the flow through the orifice plate, were theoretically analyzed, and their relationships were obtained through physical model experiments. It can be concluded that the minimum wall pressure coefficient is mainly dominated by the contraction ratio and relative thickness. The lower the contraction ratio and relative thickness are, the larger the minimum wall pressure coefficient is. The effects of the Reynolds number on the minimum wall pressure coefficient can be neglected when it is larger than 105. An empirical expression was presented to calculate the minimum wall pressure coefficient in this study.

Simultaneous Description of Activity Coefficients and Solubility with eCPA

DEFF Research Database (Denmark)

Schlaikjer, Anders; Thomsen, Kaj; Kontogeorgis, Georgios

2017-01-01

with salt specific parameters. The focus is on accurate description of the salt solubility, and low deviation correlations are obtained for all salts investigated. The inclusion of the solubility data in the parametrization has, compared to parameters only parametrized to osmotic coefficients and activity...... coefficients, not significantly affected the deviations of the osmotic coefficients and activity coefficients. The average deviations of the activity coefficient does increase slightly and it was found that the increase in deviations was almost entirely due to reduced accuracy at high temperature and high...... molality. The model is, furthermore, compared to the activity coefficient model, Extended UNIQUAC. It is shown that the eCPA provides more accurate solubility description at higher temperatures than Extended UNIQUAC but also that Extended UNIQUAC is slightly better at describing the activity coefficients...

Measuring device for the temperature coefficient of reactor moderators

International Nuclear Information System (INIS)

Nakano, Yuzo.

1987-01-01

Purpose: To rapidly determine by automatic calculation the temperature coefficient for moderators which has been determined so far by a log of manual processings. Constitution: Each of signals from a control rod position indicator, a reactor reactivity, instrument and moderator temperature meter are inputted, and each of the signals and designed valued for the doppler temperature coefficients are stored. Recurling calculation is conducted based on the reactivity and the moderator temperature at an interval where the temperature changes of the moderators are equalized at an identical control rod position, to determine isothermic coefficient. Then, the temperature coefficient for moderator are calculated from the isothermic coefficient and the doppler temperature coefficient. The relationship between the reactivity and the moderator temperature is plotted on a X-Y recorder. The stored signals and the calculated temperature coefficient for moderators are sequentially displayed and the results are printed out when the measurement is completed. According to the present device, since the real time processing is conducted, the processing time can be shortened remarkably. Accordingly, it is possible to save the man power for the test of the nuclear reactor and improve the reactor operation performance. (Kamimura, M.)

Uncertainty and confidence from the triple-network perspective

DEFF Research Database (Denmark)

White, Thomas P.; Engen, Nina Helkjær; Sørensen, Susan

2014-01-01

of environmental conditions; (ii) those regions whose activity is robustly affected by our subjective confidence; and (iii) those regions differentially activated at these contrasting times. In further meta-analyses the consistency of activation between these judgement types was assessed. Increased activation...

Non-linear Bayesian update of PCE coefficients

KAUST Repository

Litvinenko, Alexander

2014-01-06

Given: a physical system modeled by a PDE or ODE with uncertain coefficient q(?), a measurement operator Y (u(q), q), where u(q, ?) uncertain solution. Aim: to identify q(?). The mapping from parameters to observations is usually not invertible, hence this inverse identification problem is generally ill-posed. To identify q(!) we derived non-linear Bayesian update from the variational problem associated with conditional expectation. To reduce cost of the Bayesian update we offer a unctional approximation, e.g. polynomial chaos expansion (PCE). New: We apply Bayesian update to the PCE coefficients of the random coefficient q(?) (not to the probability density function of q).

Non-linear Bayesian update of PCE coefficients

KAUST Repository

Litvinenko, Alexander; Matthies, Hermann G.; Pojonk, Oliver; Rosic, Bojana V.; Zander, Elmar

2014-01-01

Given: a physical system modeled by a PDE or ODE with uncertain coefficient q(?), a measurement operator Y (u(q), q), where u(q, ?) uncertain solution. Aim: to identify q(?). The mapping from parameters to observations is usually not invertible, hence this inverse identification problem is generally ill-posed. To identify q(!) we derived non-linear Bayesian update from the variational problem associated with conditional expectation. To reduce cost of the Bayesian update we offer a unctional approximation, e.g. polynomial chaos expansion (PCE). New: We apply Bayesian update to the PCE coefficients of the random coefficient q(?) (not to the probability density function of q).

Non-vanishing of Taylor coefficients and Poincaré series

DEFF Research Database (Denmark)

O'Sullivan, C.; Risager, Morten S.

2013-01-01

We prove recursive formulas for the Taylor coefficients of cusp forms, such as Ramanujan's Delta function, at points in the upper half-plane. This allows us to show the non-vanishing of all Taylor coefficients of Delta at CM points of small discriminant as well as the non-vanishing of certain...... Poincaré series. At a "generic" point, all Taylor coefficients are shown to be non-zero. Some conjectures on the Taylor coefficients of Delta at CM points are stated....

Development of reflectance-based crop coefficients for corn

International Nuclear Information System (INIS)

Neale, C.M.U.; Bausch, W.C.; Heermann, D.F.

1989-01-01

Concurrent measurements of reflected canopy radiation and the basal crop coefficient (K^b) for corn were conducted throughout a season in order to develop a reflectance-based crop coefficient model. Reflectance was measured in Landsat Thematic Mapper bands TM3 (0.63 - 0.69 um) and TM4 (0.76 - 0.90 um) and used in the calculation of a vegetation index called the normalized difference (ND). A linear transformation of the ND was used as the reflectance-based crop coefficient (Kcr). The transformation equates the ND for dry bare soil and the ND at effective cover, to the basal crop coefficient for dry soil evaporation and at effective cover, respectively. Basal crop coefficient values for com were obtained from daily evapotranspiration measurements of corn and alfalfa, using hydraulic weighing lysimeters. The Richards growth curve function was fitted to both sets of data. The K^b values were determined to be within -2.6% and 4.7% of the K^^ values. The date of effective cover obtained from the K^b data was within four days of the date on which the ND curve reached its maxima according to the Richards function. A comparison of the Kcr with basal crop curves from the literature for several years of data indicated good agreement. Reflectance-based crop coefficients are sensitive to periods of slow and fast growth induced by weather conditions, resulting in a real time coefficient, independent from the traditional time base parameters based on the day of planting and effective cover

A study of the correlation between self-confidence and professional achievement of designers

Directory of Open Access Journals (Sweden)

Chen Rain

2017-01-01

Full Text Available This study mainly investigated which mental state of designers, self-confidence or sense of inferiority, has positive effects on professional design achievement. This study attempted to find if there is correlation between designers’ self-confidence or sense of inferiority and their professional achievement. With regard to the tendency of designers’ psychological state, the Rosenberg Self-Esteem Scale was used to measure designers’ selfconfidence, and statistical computations were made based on gathered data. This study used correlation analysis to find if confidence level of 46 seniors of Design Department is relevant to their professional achievement. The results of the study showed that confidence level of designers has a slight correlation to professional achievement. Factors leading to the study’s findings may be the small amount of sample analyzed or may be the reason that the Rosenberg Self-Esteem Scale only detected the current level of self-confidence and could not give a proper feedback on designers’ self-confidence during the entire semester. In the future, the results of this study can be considered as a pre-test experiment for a more complete study, and it is expected that results of the study can be for design educators’ reference.

A new consistent definition of the homogenized diffusion coefficient of a lattice, limitations of the homogenization concept, and discussion of previously defined coefficients

International Nuclear Information System (INIS)

Deniz, V.C.

1980-01-01

The problem concerned with the correct definition of the homogenized diffusion coefficient of a lattice, and the concurrent problem of whether or not a homogenized diffusion equation can be formally set up, is studied by a space-energy-angle dependent treatment for a general lattice cell using an operator notation which applies to any eigen-problem. A new definition of the diffusion coefficient is given, which combines within itself the individual merits of the two definitions of Benoist. The relation between the new coefficient and the ''uncorrected'' Benoist coefficient is discussed by considering continuous-spectrum and multi-group diffusion equations. Other definitions existing in the literature are briefly discussed. It is concluded that a diffusion coefficient should represent only leakage effects. A comparison is made between the homogenization approach and the approach via eigen-coefficients, and brief indications are given of a possible scheme for the latter. (author)

Systematic Risk on Istanbul Stock Exchange: Traditional Beta Coefficient Versus Downside Beta Coefficient

Directory of Open Access Journals (Sweden)

Gülfen TUNA

2013-03-01

Full Text Available The aim of this study is to test the validity of Downside Capital Asset Pricing Model (D-CAPM on the ISE. At the same time, the explanatory power of CAPM's traditional beta and D-CAPM's downside beta on the changes in the average return values are examined comparatively. In this context, the monthly data for seventy three stocks that are continuously traded on the ISE for the period 1991-2009 is used. Regression analysis is applied in this study. The research results have shown that D-CAPM is valid on the ISE. In addition, it is obtained that the power of downside beta coefficient is higher than traditional beta coefficient on explaining the return changes. Therefore, it can be said that the downside beta is superior to traditional beta in the ISE for chosen period.

Building confident organizations by filling buckets, building infrastructures, and shining the flashlight.

Science.gov (United States)

Kerfoot, Karlene

2005-04-01

Leaders have the ability to create confidence or fear in the organization. Kanter (2004) writes that confidence is the "...sweet spot between arrogance and despair" (p. 8). Overconfidence causes people to overshoot, and to assume they are invulnerable. Underconfidence is just as harmful because it leads to underinvesting in people, under-innovating, and eventually leads to the disenfranchisement of staff and poor morale. If we take Kanter's advice, we will build an infrastructure that creates confidence in everyone and the organization. But we will not stop there. We will focus "flashlights" on people and activities that are inspiring to others.

Social acceptance and population confidence in telehealth in Quebec.

Science.gov (United States)

Poder, Thomas G; Bellemare, Christian A; Bédard, Suzanne K; Lemieux, Renald

2015-02-21

Access to healthcare in remote areas is difficult and telehealth could be a promising avenue if accepted by the population. The aim of this study is to assess social acceptance and population confidence in telehealth in the Province of Quebec. We conducted a survey using a questionnaire assessing the social acceptance of and confidence level in telehealth. Two strategies were used: 1) paper questionnaires were sent to two hospitals in Quebec; and 2) online questionnaires were randomly sent by a firm specialized in online survey to a representative sample of the population of the Province of Quebec. Respondents were all residents of the Province of Quebec and 18 years and older. Questions were scored with a four-level Likert scale. A total of 1816 questionnaires were analyzed (229 written and 1,587 online questionnaires). The socio-demographic variables in our samples, especially the online questionnaires, were fairly representative of Quebec's population. Overall, social acceptance scored at 77.71% and confidence level at 65.76%. Both scores were higher in the case of treatment (3 scenarios were proposed) vs. diagnosis (p < 0.05). No difference was found when respondents were asked to respond for themselves and for a member of their family, which demonstrates a true interest in telehealth in Quebec. In addition, we found a significant difference (p < 0.05) between written and online questionnaires regarding social acceptance (80.75% vs. 77.33%) and confidence level (74.84% vs. 64.55%). These differences may be due to social desirability or avidity bias in the written questionnaires. Our results suggest that the population in Quebec encourages the development of telehealth for real time diagnosis and long distance treatment for regions deprived of healthcare professionals.

Measurements of density and of thermal expansion coefficient of sodium tetraborate (borax)-UO2 and of sodium metaborate-UO2 solutions

International Nuclear Information System (INIS)

Dalle Donne, M.; Dorner, S.

1980-12-01

Measurements have been performed of the density and volumetric thermal expansion coefficient of liquid sodium tetraborate (borax) and of sodium metaborate both pure and with two different amounts of UO 2 dissolved in each. These data are required for the design of core-catchers based on sodium borates. The measurements have been performed with the buoyancy method in the temperature range from 850 0 C to 1325 0 C. The data for the pure borax and for the sodium metaborate agree reasonably well with the data from the literature, giving confidence that the measurements are correct and the new data for the salts with UO 2 are reliable. (orig.) [de

The Applicability of Confidence Intervals of Quantiles for the Generalized Logistic Distribution

Science.gov (United States)

Shin, H.; Heo, J.; Kim, T.; Jung, Y.

2007-12-01

The generalized logistic (GL) distribution has been widely used for frequency analysis. However, there is a little study related to the confidence intervals that indicate the prediction accuracy of distribution for the GL distribution. In this paper, the estimation of the confidence intervals of quantiles for the GL distribution is presented based on the method of moments (MOM), maximum likelihood (ML), and probability weighted moments (PWM) and the asymptotic variances of each quantile estimator are derived as functions of the sample sizes, return periods, and parameters. Monte Carlo simulation experiments are also performed to verify the applicability of the derived confidence intervals of quantile. As the results, the relative bias (RBIAS) and relative root mean square error (RRMSE) of the confidence intervals generally increase as return period increases and reverse as sample size increases. And PWM for estimating the confidence intervals performs better than the other methods in terms of RRMSE when the data is almost symmetric while ML shows the smallest RBIAS and RRMSE when the data is more skewed and sample size is moderately large. The GL model was applied to fit the distribution of annual maximum rainfall data. The results show that there are little differences in the estimated quantiles between ML and PWM while distinct differences in MOM.

Determination of confidence limits for experiments with low numbers of counts

International Nuclear Information System (INIS)

Kraft, R.P.; Burrows, D.N.; Nousek, J.A.

1991-01-01

Two different methods, classical and Bayesian, for determining confidence intervals involving Poisson-distributed data are compared. Particular consideration is given to cases where the number of counts observed is small and is comparable to the mean number of background counts. Reasons for preferring the Bayesian over the classical method are given. Tables of confidence limits calculated by the Bayesian method are provided for quick reference. 12 refs

Solving Variable Coefficient Fourth-Order Parabolic Equation by ...

African Journals Online (AJOL)

Solving Variable Coefficient Fourth-Order Parabolic Equation by Modified initial guess Variational ... variable coefficient fourth order parabolic partial differential equations. The new method shows rapid convergence to the exact solution.

Suicide-Related Knowledge and Confidence Among Behavioral Health Care Staff in Seven States.

Science.gov (United States)

Silva, Caroline; Smith, April R; Dodd, Dorian R; Covington, David W; Joiner, Thomas E

2016-11-01

Death by suicide is a serious and growing public health concern in the United States. This noncontrolled, naturalistic study examined professionals' knowledge about suicide and confidence in working with suicidal individuals, comparing those who had received either of two gatekeeper trainings-Question, Persuade, and Refer (QPR) or Applied Suicide Intervention Skills Training (ASIST)-or other suicide-relevant training or no training. Participants (N=16,693) were individuals in various professional roles in the field of behavioral health care in Indiana, Kentucky, New York, Pennsylvania, Tennessee, Texas, and Utah. Participants completed a survey assessing suicide knowledge and skills confidence. Most participants (52.9%) reported no previous suicide prevention or assessment training. Individuals with suicide-relevant training demonstrated greater suicide knowledge and confidence than those with no such training. Among those who had received any training, no differences were found in suicide knowledge; however, individuals who had received ASIST reported greater confidence in working with suicidal individuals, compared with those who had received other training. Professional role and prior experience with a client who had died by suicide had significant positive relationships with suicide knowledge and confidence. Regional differences emerged between states and are examined within the context of statewide suicide prevention initiatives. Increasing access to and incentives for participating in suicide-relevant training among behavioral health care staff may foster a more knowledgeable and confident group of gatekeepers. Future research should examine whether increases in knowledge and confidence among staff translate into actual changes in practice that help protect and serve at-risk individuals.

Fechner’s law in metacognition: a quantitative model of visual working memory confidence

Science.gov (United States)

van den Berg, Ronald; Yoo, Aspen H.; Ma, Wei Ji

2016-01-01

Although visual working memory (VWM) has been studied extensively, it is unknown how people form confidence judgments about their memories. Peirce (1878) speculated that Fechner’s law – which states that sensation is proportional to the logarithm of stimulus intensity – might apply to confidence reports. Based on this idea, we hypothesize that humans map the precision of their VWM contents to a confidence rating through Fechner’s law. We incorporate this hypothesis into the best available model of VWM encoding and fit it to data from a delayed-estimation experiment. The model provides an excellent account of human confidence rating distributions as well as the relation between performance and confidence. Moreover, the best-fitting mapping in a model with a highly flexible mapping closely resembles the logarithmic mapping, suggesting that no alternative mapping exists that accounts better for the data than Fechner's law. We propose a neural implementation of the model and find that this model also fits the behavioral data well. Furthermore, we find that jointly fitting memory errors and confidence ratings boosts the power to distinguish previously proposed VWM encoding models by a factor of 5.99 compared to fitting only memory errors. Finally, we show that Fechner's law also accounts for metacognitive judgments in a word recognition memory task, which is a first indication that it may be a general law in metacognition. Our work presents the first model to jointly account for errors and confidence ratings in VWM and could lay the groundwork for understanding the computational mechanisms of metacognition. PMID:28221087

Clustering coefficient and community structure of bipartite networks

Science.gov (United States)

Zhang, Peng; Wang, Jinliang; Li, Xiaojia; Li, Menghui; Di, Zengru; Fan, Ying

2008-12-01

Many real-world networks display natural bipartite structure, where the basic cycle is a square. In this paper, with the similar consideration of standard clustering coefficient in binary networks, a definition of the clustering coefficient for bipartite networks based on the fraction of squares is proposed. In order to detect community structures in bipartite networks, two different edge clustering coefficients LC4 and LC3 of bipartite networks are defined, which are based on squares and triples respectively. With the algorithm of cutting the edge with the least clustering coefficient, communities in artificial and real world networks are identified. The results reveal that investigating bipartite networks based on the original structure can show the detailed properties that is helpful to get deep understanding about the networks.

Does interaction matter? Testing whether a confidence heuristic can replace interaction in collective decision-making.

Science.gov (United States)

Bang, Dan; Fusaroli, Riccardo; Tylén, Kristian; Olsen, Karsten; Latham, Peter E; Lau, Jennifer Y F; Roepstorff, Andreas; Rees, Geraint; Frith, Chris D; Bahrami, Bahador

2014-05-01

In a range of contexts, individuals arrive at collective decisions by sharing confidence in their judgements. This tendency to evaluate the reliability of information by the confidence with which it is expressed has been termed the 'confidence heuristic'. We tested two ways of implementing the confidence heuristic in the context of a collective perceptual decision-making task: either directly, by opting for the judgement made with higher confidence, or indirectly, by opting for the faster judgement, exploiting an inverse correlation between confidence and reaction time. We found that the success of these heuristics depends on how similar individuals are in terms of the reliability of their judgements and, more importantly, that for dissimilar individuals such heuristics are dramatically inferior to interaction. Interaction allows individuals to alleviate, but not fully resolve, differences in the reliability of their judgements. We discuss the implications of these findings for models of confidence and collective decision-making. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Impact of an Advanced Cardiac Life Support Simulation Laboratory Experience on Pharmacy Student Confidence and Knowledge.

Science.gov (United States)

Maxwell, Whitney D; Mohorn, Phillip L; Haney, Jason S; Phillips, Cynthia M; Lu, Z Kevin; Clark, Kimberly; Corboy, Alex; Ragucci, Kelly R

2016-10-25

Objective. To assess the impact of an advanced cardiac life support (ACLS) simulation on pharmacy student confidence and knowledge. Design. Third-year pharmacy students participated in a simulation experience that consisted of team roles training, high-fidelity ACLS simulations, and debriefing. Students completed a pre/postsimulation confidence and knowledge assessment. Assessment. Overall, student knowledge assessment scores and student confidence scores improved significantly. Student confidence and knowledge changes from baseline were not significantly correlated. Conversely, a significant, weak positive correlation between presimulation studying and both presimulation confidence and presimulation knowledge was discovered. Conclusions. Overall, student confidence and knowledge assessment scores in ACLS significantly improved from baseline; however, student confidence and knowledge were not significantly correlated.

The effect of in-training assessment on clinical confidence in postgraduate education

DEFF Research Database (Denmark)

Ringsted, Charlotte; Pallisgaard, Jane; Østergaard, Doris

2004-01-01

doctors' self-confidence in clinical performance before (in 2001) and 2 years after (in 2003) the introduction of an ITA programme. Respondents indicated confidence on a 155-item questionnaire related to performance of clinical skills and tasks reflecting broad aspects of competence. A total of 23...

An Introduction to Confidence Intervals for Both Statistical Estimates and Effect Sizes.

Science.gov (United States)

Capraro, Mary Margaret

This paper summarizes methods of estimating confidence intervals, including classical intervals and intervals for effect sizes. The recent American Psychological Association (APA) Task Force on Statistical Inference report suggested that confidence intervals should always be reported, and the fifth edition of the APA "Publication Manual"…

Does Classroom Management Coursework Influence Pre-service Teachers' Perceived Preparedness or Confidence?

Science.gov (United States)

O'Neill, Sue; Stephenson, Jennifer

2012-01-01

There has been conjecture that completing focused coursework units on classroom management during pre-service teacher preparation might lead to increased feelings of preparedness and confidence. This study reports the preparedness in managing specific problem behaviours, familiarity, and confidence in using management strategies and models of…

Principles of psychological confidence of NPP operators

International Nuclear Information System (INIS)

Alpeev, A.S.

1994-01-01

The problems of operator interaction with subsystems supporting his activity are discussed from the point of view of formation of his psychological confidence on the basis of the automation intellectual means capabilities. The functions of operator activity supporting subsystems, which realization will provide to decrease greatly the portion of accidents at NPPs connected with mistakes in operator actions, are derived. 6 refs

Evidence for a confidence-accuracy relationship in memory for same- and cross-race faces.

Science.gov (United States)

Nguyen, Thao B; Pezdek, Kathy; Wixted, John T

2017-12-01

Discrimination accuracy is usually higher for same- than for cross-race faces, a phenomenon known as the cross-race effect (CRE). According to prior research, the CRE occurs because memories for same- and cross-race faces rely on qualitatively different processes. However, according to a continuous dual-process model of recognition memory, memories that rely on qualitatively different processes do not differ in recognition accuracy when confidence is equated. Thus, although there are differences in overall same- and cross-race discrimination accuracy, confidence-specific accuracy (i.e., recognition accuracy at a particular level of confidence) may not differ. We analysed datasets from four recognition memory studies on same- and cross-race faces to test this hypothesis. Confidence ratings reliably predicted recognition accuracy when performance was above chance levels (Experiments 1, 2, and 3) but not when performance was at chance levels (Experiment 4). Furthermore, at each level of confidence, confidence-specific accuracy for same- and cross-race faces did not significantly differ when overall performance was above chance levels (Experiments 1, 2, and 3) but significantly differed when overall performance was at chance levels (Experiment 4). Thus, under certain conditions, high-confidence same-race and cross-race identifications may be equally reliable.

Balance confidence is related to features of balance and gait in individuals with chronic stroke

Science.gov (United States)

Schinkel-Ivy, Alison; Wong, Jennifer S.; Mansfield, Avril

2016-01-01

Reduced balance confidence is associated with impairments in features of balance and gait in individuals with sub-acute stroke. However, an understanding of these relationships in individuals at the chronic stage of stroke recovery is lacking. This study aimed to quantify relationships between balance confidence and specific features of balance and gait in individuals with chronic stroke. Participants completed a balance confidence questionnaire and clinical balance assessment (quiet standing, walking, and reactive stepping) at 6 months post-discharge from inpatient stroke rehabilitation. Regression analyses were performed using balance confidence as a predictor variable and quiet standing, walking, and reactive stepping outcome measures as the dependent variables. Walking velocity was positively correlated with balance confidence, while medio-lateral centre of pressure excursion (quiet standing) and double support time, step width variability, and step time variability (walking) were negatively correlated with balance confidence. This study provides insight into the relationships between balance confidence and balance and gait measures in individuals with chronic stroke, suggesting that individuals with low balance confidence exhibited impaired control of quiet standing as well as walking characteristics associated with cautious gait strategies. Future work should identify the direction of these relationships to inform community-based stroke rehabilitation programs for individuals with chronic stroke, and determine the potential utility of incorporating interventions to improve balance confidence into these programs. PMID:27955809

Confidence limits for parameters of Poisson and binomial distributions

International Nuclear Information System (INIS)

Arnett, L.M.

1976-04-01

The confidence limits for the frequency in a Poisson process and for the proportion of successes in a binomial process were calculated and tabulated for the situations in which the observed values of the frequency or proportion and an a priori distribution of these parameters are available. Methods are used that produce limits with exactly the stated confidence levels. The confidence interval [a,b] is calculated so that Pr [a less than or equal to lambda less than or equal to b c,μ], where c is the observed value of the parameter, and μ is the a priori hypothesis of the distribution of this parameter. A Bayesian type analysis is used. The intervals calculated are narrower and appreciably different from results, known to be conservative, that are often used in problems of this type. Pearson and Hartley recognized the characteristics of their methods and contemplated that exact methods could someday be used. The calculation of the exact intervals requires involved numerical analyses readily implemented only on digital computers not available to Pearson and Hartley. A Monte Carlo experiment was conducted to verify a selected interval from those calculated. This numerical experiment confirmed the results of the analytical methods and the prediction of Pearson and Hartley that their published tables give conservative results

Improved diffusion coefficients generated from Monte Carlo codes

International Nuclear Information System (INIS)

Herman, B. R.; Forget, B.; Smith, K.; Aviles, B. N.

2013-01-01

Monte Carlo codes are becoming more widely used for reactor analysis. Some of these applications involve the generation of diffusion theory parameters including macroscopic cross sections and diffusion coefficients. Two approximations used to generate diffusion coefficients are assessed using the Monte Carlo code MC21. The first is the method of homogenization; whether to weight either fine-group transport cross sections or fine-group diffusion coefficients when collapsing to few-group diffusion coefficients. The second is a fundamental approximation made to the energy-dependent P1 equations to derive the energy-dependent diffusion equations. Standard Monte Carlo codes usually generate a flux-weighted transport cross section with no correction to the diffusion approximation. Results indicate that this causes noticeable tilting in reconstructed pin powers in simple test lattices with L2 norm error of 3.6%. This error is reduced significantly to 0.27% when weighting fine-group diffusion coefficients by the flux and applying a correction to the diffusion approximation. Noticeable tilting in reconstructed fluxes and pin powers was reduced when applying these corrections. (authors)

The influence of hydrogen bonding on partition coefficients

Science.gov (United States)

Borges, Nádia Melo; Kenny, Peter W.; Montanari, Carlos A.; Prokopczyk, Igor M.; Ribeiro, Jean F. R.; Rocha, Josmar R.; Sartori, Geraldo Rodrigues

2017-02-01

This Perspective explores how consideration of hydrogen bonding can be used to both predict and better understand partition coefficients. It is shown how polarity of both compounds and substructures can be estimated from measured alkane/water partition coefficients. When polarity is defined in this manner, hydrogen bond donors are typically less polar than hydrogen bond acceptors. Analysis of alkane/water partition coefficients in conjunction with molecular electrostatic potential calculations suggests that aromatic chloro substituents may be less lipophilic than is generally believed and that some of the effect of chloro-substitution stems from making the aromatic π-cloud less available to hydrogen bond donors. Relationships between polarity and calculated hydrogen bond basicity are derived for aromatic nitrogen and carbonyl oxygen. Aligned hydrogen bond acceptors appear to present special challenges for prediction of alkane/water partition coefficients and this may reflect `frustration' of solvation resulting from overlapping hydration spheres. It is also shown how calculated hydrogen bond basicity can be used to model the effect of aromatic aza-substitution on octanol/water partition coefficients.

Amide temperature coefficients in the protein G B1 domain

International Nuclear Information System (INIS)

Tomlinson, Jennifer H.; Williamson, Mike P.

2012-01-01

Temperature coefficients have been measured for backbone amide 1 H and 15 N nuclei in the B1 domain of protein G (GB1), using temperatures in the range 283–313 K, and pH values from 2.0 to 9.0. Many nuclei display pH-dependent coefficients, which were fitted to one or two pK a values. 1 H coefficients showed the expected behaviour, in that hydrogen-bonded amides have less negative values, but for those amides involved in strong hydrogen bonds in regular secondary structure there is a negative correlation between strength of hydrogen bond and size of temperature coefficient. The best correlation to temperature coefficient is with secondary shift, indicative of a very approximately uniform thermal expansion. The largest pH-dependent changes in coefficient are for amides in loops adjacent to sidechain hydrogen bonds rather than the amides involved directly in hydrogen bonds, indicating that the biggest determinant of the temperature coefficient is temperature-dependent loss of structure, not hydrogen bonding. Amide 15 N coefficients have no clear relationship with structure.

Probability and Confidence Trade-space (PACT) Evaluation: Accounting for Uncertainty in Sparing Assessments

Science.gov (United States)

Anderson, Leif; Box, Neil; Carter, Katrina; DiFilippo, Denise; Harrington, Sean; Jackson, David; Lutomski, Michael

2012-01-01

There are two general shortcomings to the current annual sparing assessment: 1. The vehicle functions are currently assessed according to confidence targets, which can be misleading- overly conservative or optimistic. 2. The current confidence levels are arbitrarily determined and do not account for epistemic uncertainty (lack of knowledge) in the ORU failure rate. There are two major categories of uncertainty that impact Sparing Assessment: (a) Aleatory Uncertainty: Natural variability in distribution of actual failures around an Mean Time Between Failure (MTBF) (b) Epistemic Uncertainty : Lack of knowledge about the true value of an Orbital Replacement Unit's (ORU) MTBF We propose an approach to revise confidence targets and account for both categories of uncertainty, an approach we call Probability and Confidence Trade-space (PACT) evaluation.

Self-confidence in financial analysis: a study of younger and older male professional analysts.

Science.gov (United States)

Webster, R L; Ellis, T S

2001-06-01

Measures of reported self-confidence in performing financial analysis by 59 professional male analysts, 31 born between 1946 and 1964 and 28 born between 1965 and 1976, were investigated and reported. Self-confidence in one's ability is important in the securities industry because it affects recommendations and decisions to buy, sell, and hold securities. The respondents analyzed a set of multiyear corporate financial statements and reported their self-confidence in six separate financial areas. Data from the 59 male financial analysts were tallied and analyzed using both univariate and multivariate statistical tests. Rated self-confidence was not significantly different for the younger and the older men. These results are not consistent with a similar prior study of female analysts in which younger women showed significantly higher self-confidence than older women.

Exact nonparametric confidence bands for the survivor function.

Science.gov (United States)

Matthews, David

2013-10-12

A method to produce exact simultaneous confidence bands for the empirical cumulative distribution function that was first described by Owen, and subsequently corrected by Jager and Wellner, is the starting point for deriving exact nonparametric confidence bands for the survivor function of any positive random variable. We invert a nonparametric likelihood test of uniformity, constructed from the Kaplan-Meier estimator of the survivor function, to obtain simultaneous lower and upper bands for the function of interest with specified global confidence level. The method involves calculating a null distribution and associated critical value for each observed sample configuration. However, Noe recursions and the Van Wijngaarden-Decker-Brent root-finding algorithm provide the necessary tools for efficient computation of these exact bounds. Various aspects of the effect of right censoring on these exact bands are investigated, using as illustrations two observational studies of survival experience among non-Hodgkin's lymphoma patients and a much larger group of subjects with advanced lung cancer enrolled in trials within the North Central Cancer Treatment Group. Monte Carlo simulations confirm the merits of the proposed method of deriving simultaneous interval estimates of the survivor function across the entire range of the observed sample. This research was supported by the Natural Sciences and Engineering Research Council (NSERC) of Canada. It was begun while the author was visiting the Department of Statistics, University of Auckland, and completed during a subsequent sojourn at the Medical Research Council Biostatistics Unit in Cambridge. The support of both institutions, in addition to that of NSERC and the University of Waterloo, is greatly appreciated.

The Selective Cue Integration Framework: A Theory of Postidentification Witness Confidence Assessment

Science.gov (United States)

Charman, Steve D.; Carlucci, Marianna; Vallano, Jon; Gregory, Amy Hyman

2010-01-01

The current manuscript proposes a theory of how witnesses assess their confidence following a lineup identification, called the selective cue integration framework (SCIF). Drawing from past research on the postidentification feedback effect, the SCIF details a three-stage process of confidence assessment that is based largely on a…

Kinetic theory of the interdiffusion coefficient in dense plasmas

International Nuclear Information System (INIS)

Boercker, D.B.

1986-08-01

Naive applications of Spitzer's theory to very dense plasmas can lead to negative diffusion coefficients. The interdiffusion coefficients in Binary Ionic Mixtures (two species of point ions in a uniform neutralizing background) have been calculated recently using molecular dynamics techniques. These calculations can provide useful benchmarks for theoretical evaluations of the diffusion coefficient in dense plasma mixtures. This paper gives a brief description of a kinetic theoretic approximation to the diffusion coefficient which generalizes Spitzer to high density and is in excellent agreement with the computer simulations. 15 refs., 1 fig., 2 tabs

Higher-order Cn dispersion coefficients for hydrogen

International Nuclear Information System (INIS)

Mitroy, J.; Bromley, M.W.J.

2005-01-01

The complete set of second-, third-, and fourth-order van der Waals coefficients C n up to n=32 for the H(1s)-H(1s) dimer have been determined. They are computed by diagonalizing the nonrelativistic Hamiltonian for hydrogen to obtain a set of pseudostates that are used to evaluate the appropriate sum rules. A study of the convergence pattern for n≤16 indicates that all the C n/16 coefficients are accurate to 13 significant digits. The relative size of the fourth-order C n (4) to the second-order C n (2) coefficients is seen to increase as n increases and at n=32 the fourth-order term is actually larger

Determination of beta attenuation coefficients by means of timing method

International Nuclear Information System (INIS)

Ermis, E.E.; Celiktas, C.

2012-01-01

Highlights: ► Beta attenuation coefficients of absorber materials were found in this study. ► For this process, a new method (timing method) was suggested. ► The obtained beta attenuation coefficients were compatible with the results from the traditional one. ► The timing method can be used to determine beta attenuation coefficient. - Abstract: Using a counting system with plastic scintillation detector, beta linear and mass attenuation coefficients were determined for bakelite, Al, Fe and plexiglass absorbers by means of timing method. To show the accuracy and reliability of the obtained results through this method, the coefficients were also found via conventional energy method. Obtained beta attenuation coefficients from both methods were compared with each other and the literature values. Beta attenuation coefficients obtained through timing method were found to be compatible with the values obtained from conventional energy method and the literature.

Role perception, job-related tension and organisational confidence ...

African Journals Online (AJOL)

Role perception, job-related tension and organisational confidence of the village extension workers in Nsukka zone of Enugu State Agricultural Development ... Data for the study were collected through structured questionnaire administered on 44 VEWS selected, using ... their role-expectations as being important. Many of ...

Mayer coefficients in two-dimensional Coulomb systems

International Nuclear Information System (INIS)

Speer, E.R.

1986-01-01

It is shown that, for neutral systems of particles of arbitrary charges in two dimensions, with hard cores, coefficients of the Mayer series for the pressure exist in the thermodynamic limit below certain thresholds in the temperature. The methods used here apply also to correlation functions and yield bounds on the asymptotic behavior of their Mayer coefficients

Helioseismic Solar Cycle Changes and Splitting Coefficients

Indian Academy of Sciences (India)

tribpo

Abstract. Using the GONG data for a period over four years, we have studied the variation of frequencies and splitting coefficients with solar cycle. Frequencies and even-order coefficients are found to change signi- ficantly with rising phase of the solar cycle. We also find temporal varia- tions in the rotation rate near the solar ...

Estimation of the thermal diffusion coefficient in fusion plasmas taking frequency measurement uncertainties into account

International Nuclear Information System (INIS)

Van Berkel, M; Hogeweij, G M D; Van den Brand, H; De Baar, M R; Zwart, H J; Vandersteen, G

2014-01-01

In this paper, the estimation of the thermal diffusivity from perturbative experiments in fusion plasmas is discussed. The measurements used to estimate the thermal diffusivity suffer from stochastic noise. Accurate estimation of the thermal diffusivity should take this into account. It will be shown that formulas found in the literature often result in a thermal diffusivity that has a bias (a difference between the estimated value and the actual value that remains even if more measurements are added) or have an unnecessarily large uncertainty. This will be shown by modeling a plasma using only diffusion as heat transport mechanism and measurement noise based on ASDEX Upgrade measurements. The Fourier coefficients of a temperature perturbation will exhibit noise from the circular complex normal distribution (CCND). Based on Fourier coefficients distributed according to a CCND, it is shown that the resulting probability density function of the thermal diffusivity is an inverse non-central chi-squared distribution. The thermal diffusivity that is found by sampling this distribution will always be biased, and averaging of multiple estimated diffusivities will not necessarily improve the estimation. Confidence bounds are constructed to illustrate the uncertainty in the diffusivity using several formulas that are equivalent in the noiseless case. Finally, a different method of averaging, that reduces the uncertainty significantly, is suggested. The methodology is also extended to the case where damping is included, and it is explained how to include the cylindrical geometry. (paper)

Knee Confidence as it Relates to Self-Reported and Objective Correlates of Knee Osteoarthritis

DEFF Research Database (Denmark)

Skou, Søren T; Rasmussen, Sten; Simonsen, Ole

2015-01-01

osteoarthritis (OA). Background Lack of knee confidence is a frequent symptom in patients with knee OA, but little is known of associations between knee confidence and other common correlates of knee OA. Methods Baseline data from 220 patients with knee OA were applied in ordinal regression analyses, with knee...... confidence, assessed using item Q3 of the Knee injury and Osteoarthritis Outcome Score, as the dependent variable and self-reported (pain on walking, general health, fear of movement, self-efficacy, function, and previous serious injury) and objective measures (muscle strength, 20-m walk time.......21; 95% CI: 1.09, 1.34), and general health (OR = 0.024; 95% CI: 0.002, 0.259) explained 19% of the variance in knee confidence (Pcommon finding in individuals with knee OA. Pain on walking was confirmed as a correlate of knee confidence, whereas...

Preparedness for eHealth: Health Sciences Students’ Knowledge, Skills, and Confidence

Directory of Open Access Journals (Sweden)

Mary Lam

2016-07-01

Full Text Available There is increasing recognition of the role eHealth will play in the effective and efficient delivery of healthcare. This research challenges the assumption that students enter university as digital natives, able to confidently and competently adapt their use of information and communication technology (ICT to new contexts. This study explored health sciences students’ preparedness for working, and leading change, in eHealth-enabled environments. Using a cross-sectional study design, 420 undergraduate and postgraduate students participated in an online survey investigating their understanding of and attitude towards eHealth, frequency of online activities and software usage, confidence learning and using ICTs, and perceived learning needs. Although students reported that they regularly engaged with a wide range of online activities and software and were confident learning new ICT skills especially where they have sufficient time or support, their understanding of eHealth was uncertain or limited. Poor understanding of and difficulty translating skills learned in personal contexts to the professional context may impair graduates ability to con-fidently engage in the eHealth-enabled workplace. These results suggest educators need to scaffold the learning experience to ensure students build on their ICT knowledge to transfer this to their future workplaces.

Confidence amongst Multidisciplinary Professionals in Managing Paediatric Rheumatic Disease in Australia

Directory of Open Access Journals (Sweden)

Samuel Cassidy

2018-01-01

Full Text Available Objective. Interprofessional collaboration is a crucial component of care for children with rheumatic disease. Interprofessional care, when delivered appropriately, prevents disability and improves long-term prognosis in this vulnerable group. Methods. The aim of this survey was to explore allied health professionals’ and nurses’ confidence in treating paediatric rheumatology patients. Results. Overall, 117 participants were recruited, 77.9% of participants reported being “not confident at all,” “not confident,” or “neutral” in treating children with rheumatic diseases (RD despite 65.1% of participants reporting having treated >1 paediatric rheumatology case in the past month. Furthermore, 67.2% of participants felt their undergraduate education in paediatric rheumatology was inadequate. “Journals” or “texts books” were used by 49.3% of participants as their primary source of continuing professional development (CPD and 39.3% of participants indicated that they did not undertake any CPD related to paediatric rheumatology. Small group and online education were perceived to be potentially of “great benefit” for CPD. Conclusion. This paper highlights allied health professionals’ and nurses’ perceived inadequacy of their undergraduate education in paediatric RD and their low confidence in recognising and treating RD. Undergraduate and postgraduate education opportunities focusing on interprofessional collaboration should be developed to address this workforce deficiency.

Changes in Electrokinetic Coupling Coefficients of Granite under Triaxial Deformation

Directory of Open Access Journals (Sweden)

Osamu Kuwano

2012-01-01

Full Text Available Electrokinetic phenomena are believed to be the most likely origin of electromagnetic signals preceding or accompanying earthquakes. The intensity of the source current due to the electrokinetic phenomena is determined by the fluid flux and the electrokinetic coupling coefficient called streaming current coefficient; therefore, how the coefficient changes before rupture is essential. Here, we show how the electrokinetic coefficients change during the rock deformation experiment up to failure. The streaming current coefficient did not increase before failure, but continued to decrease up to failure, which is explained in terms of the elastic closure of capillary. On the other hand, the streaming potential coefficient, which is the product of the streaming current coefficient and bulk resistivity of the rock, increased at the onset of dilatancy. It may be due to change in bulk resistivity. Our result indicates that the zeta potential of the newly created surface does not change so much from that of the preexisting fluid rock interface.

Reaction rate calculations via transmission coefficients

International Nuclear Information System (INIS)

Feit, M.D.; Alder, B.J.

1985-01-01

The transmission coefficient of a wavepacket traversing a potential barrier can be determined by steady state calculations carried out in imaginary time instead of by real time dynamical calculations. The general argument is verified for the Eckart barrier potential by a comparison of transmission coefficients calculated from real and imaginary time solutions of the Schroedinger equation. The correspondence demonstrated here allows a formulation for the reaction rate that avoids difficulties due to both rare events and explicitly time dependent calculations. 5 refs., 2 figs

Radioactive waste and civil society: Toward confidence and efficiency

International Nuclear Information System (INIS)

Ferte, Jacques de la

2001-01-01

Radioactive waste management is a typical area where a confident and efficient relationship between decision makers and civil society is required to achieve progress. The Radioactive waste management community must now learn the lessons and borrow from the good and bad experiences of government and industry in the area of good governance. Key ingredients include not only good science and technology, but also an early association of stakeholders with the waste management development process, so as to care for social values and generate confidence in the public, notably at the local level. The new NEA Forum will now organise its future work around this concept, collecting and sharing the experience among its members, and working together in an on-going multi-year programme

Errors and Predictors of Confidence in Condom Use amongst Young Australians Attending a Music Festival

OpenAIRE

Hall, Karina M.; Brieger, Daniel G.; De Silva, Sukhita H.; Pfister, Benjamin F.; Youlden, Daniel J.; John-Leader, Franklin; Pit, Sabrina W.

2016-01-01

Objectives. To determine the confidence and ability to use condoms correctly and consistently and the predictors of confidence in young Australians attending a festival. Methods. 288 young people aged 18 to 29 attending a mixed-genre music festival completed a survey measuring demographics, self-reported confidence using condoms, ability to use condoms, and issues experienced when using condoms in the past 12 months. Results. Self-reported confidence using condoms was high (77%). Multivariate...

Effect of rolling motion on the expansion and contraction loss coefficients

International Nuclear Information System (INIS)

Yan, B.H.; Gu, H.Y.

2013-01-01

Highlights: ► The expansion and contraction loss coefficients in rolling motion are analyzed. ► Effects of rolling motion on the expansion and contraction loss coefficients are different. ► The spanwise and transverse additional forces contribute slightly to the local loss. ► The oscillations of loss coefficients increase as the strengthening of rolling motion. - Abstract: The sudden expansion and sudden contraction loss coefficients in rolling motion are investigated with CFD code FLUENT. The calculation results are validated with experimental and theoretical results in steady state. The effects of rolling motion on the expansion and contraction loss coefficients are different. The effects of spanwise and transverse additional forces on the expansion and contraction loss coefficients are weak. The effect of velocity oscillation on the contraction loss coefficient is more significant than that on the expansion loss coefficient. The oscillation of local loss coefficient also becomes more and more irregular as the strengthening of rolling motion

Theoretical investigation of the extinction coefficient of magnetic fluid

Energy Technology Data Exchange (ETDEWEB)

Fang Xiaopeng; Xuan Yimin, E-mail: ymxuan@mail.njust.edu.cn; Li Qiang [Nanjing University of Science and Technology, School of Energy and Power Engineering (China)

2013-05-15

A new theoretical approach for calculating the extinction coefficient of magnetic fluid is proposed, which is based on molecular dynamics (MD) simulation and T-matrix method. By means of this approach, the influence of particle diameter, particle volume fraction, and external magnetic filed on the extinction coefficient of magnetic fluid is investigated. The results show that the extinction coefficient of the magnetic fluid linearly increases with increase in the particle volume fraction. For a given particle volume fraction, the extinction coefficient increases with increase in the particle diameter which varies from 5 to 20 nm. When a uniform external magnetic filed is applied to the magnetic fluid, the extinction coefficient of the magnetic fluid presents an anisotropic feature. These results agree well with the reported experimental results. The proposed approach is applicable to investigating the optical properties of magnetic fluids.

Technique for Determining Lock Coefficient of Differential "Quif"

Directory of Open Access Journals (Sweden)

A. B. Fominyh

2015-01-01

Full Text Available Increasing the traction qualities of cars on the black ice and snow-covered roads is a relevant task. There are two ways to solve this task, i.e. optimize distribution of the power stream between the driving wheels of the car; introduce a differential (differentials of the increased friction in transmission.Now, an installation of the increased friction differential in transmission is the most widespread measure to increase traction properties of cars. The differential of design "Quif" is one of such differentials. To estimate the efficiency degree of using such a differential is possible either experimentally or theoretically. In case of theoretically determined usefulness of this differential design, as an estimate indicator of the differential installation in transmission a coefficient of lock is accepted.The article considers an algorithm and a technique to calculate a lock coefficient of the differential design "Quif" allowing us to define numeric values of the lock coefficient of such differential at designing stage. It also considers how the lock coefficient depends on the gearing angle and tilt angle of the gear wheel teeth of differential. The given estimating algorithm of designated parameter of differential has more logical and compact structure with regard to the known ones. The lock coefficient values calculated by the offered technique differ from the experimental data by no more than 12%. Taking into account abovementioned, the presented technique for calculating lock coefficient of differential "Quif" is advisable for practical application.

Reactor kinetics revisited: a coefficient based model (CBM)

International Nuclear Information System (INIS)

Ratemi, W.M.

2011-01-01

In this paper, a nuclear reactor kinetics model based on Guelph expansion coefficients calculation ( Coefficients Based Model, CBM), for n groups of delayed neutrons is developed. The accompanying characteristic equation is a polynomial form of the Inhour equation with the same coefficients of the CBM- kinetics model. Those coefficients depend on Universal abc- values which are dependent on the type of the fuel fueling a nuclear reactor. Furthermore, such coefficients are linearly dependent on the inserted reactivity. In this paper, the Universal abc- values have been presented symbolically, for the first time, as well as with their numerical values for U-235 fueled reactors for one, two, three, and six groups of delayed neutrons. Simulation studies for constant and variable reactivity insertions are made for the CBM kinetics model, and a comparison of results, with numerical solutions of classical kinetics models for one, two, three, and six groups of delayed neutrons are presented. The results show good agreements, especially for single step insertion of reactivity, with the advantage of the CBM- solution of not encountering the stiffness problem accompanying the numerical solutions of the classical kinetics model. (author)

Pancreatic enzyme replacement therapy in cystic fibrosis: dose, variability and coefficient of fat absorption

Directory of Open Access Journals (Sweden)

Joaquim Calvo-Lerma

Full Text Available Objectives: Pancreatic enzyme replacement therapy (PERT remains a backbone in the nutritional treatment of cystic fibrosis. Currently, there is a lack of an evidence-based tool that allows dose adjustment. To date, no studies have found an association between PERT dose and fat absorption. Therefore, the aim of the study was to assess the influence of both the PERT dose and the variability in this dose on the coefficient of fat absorption (CFA. Methods: This is a retrospective longitudinal study of 16 pediatric patients (192 food records with three consecutive visits to the hospital over a twelve-month period. Dietary fat intake and PERT were assessed via a four-day food record and fat content in stools was determined by means of a three-day stool sample collection. A beta regression model was built to explain the association between the CFA and the interaction between the PERT dose (lipase units [LU]/g dietary fat and the variability in the PERT dose (standard deviation [SD]. Results: The coefficient of fat absorption increased with the PERT dose when the variability in the dose was low. In contrast, even at the highest PERT dose values, the CFA decreased when the variability was high. The confidence interval suggested an association, although the analysis was not statistically significant. Conclusion: The variability in the PERT dose adjustment should be taken into consideration when performing studies on PERT efficiency. A clinical goal should be the maintenance of a constant PERT dose rather than trying to obtain an optimal value.

Pancreatic enzyme replacement therapy in cystic fibrosis: dose, variability and coefficient of fat absorption.

Science.gov (United States)

Calvo-Lerma, Joaquim; Martínez-Barona, Sandra; Masip, Etna; Fornés, Victoria; Ribes-Koninckx, Carmen

2017-10-01

Pancreatic enzyme replacement therapy (PERT) remains a backbone in the nutritional treatment of cystic fibrosis. Currently, there is a lack of an evidence-based tool that allows dose adjustment. To date, no studies have found an association between PERT dose and fat absorption. Therefore, the aim of the study was to assess the influence of both the PERT dose and the variability in this dose on the coefficient of fat absorption (CFA). This is a retrospective longitudinal study of 16 pediatric patients (192 food records) with three consecutive visits to the hospital over a twelve-month period. Dietary fat intake and PERT were assessed via a four-day food record and fat content in stools was determined by means of a three-day stool sample collection. A beta regression model was built to explain the association between the CFA and the interaction between the PERT dose (lipase units [LU]/g dietary fat) and the variability in the PERT dose (standard deviation [SD]). The coefficient of fat absorption increased with the PERT dose when the variability in the dose was low. In contrast, even at the highest PERT dose values, the CFA decreased when the variability was high. The confidence interval suggested an association, although the analysis was not statistically significant. The variability in the PERT dose adjustment should be taken into consideration when performing studies on PERT efficiency. A clinical goal should be the maintenance of a constant PERT dose rather than trying to obtain an optimal value.