Longitudinal associations between exercise identity and exercise motivation: A multilevel growth curve model approach.

Science.gov (United States)

Ntoumanis, N; Stenling, A; Thøgersen-Ntoumani, C; Vlachopoulos, S; Lindwall, M; Gucciardi, D F; Tsakonitis, C

2018-02-01

Past work linking exercise identity and exercise motivation has been cross-sectional. This is the first study to model the relations between different types of exercise identity and exercise motivation longitudinally. Understanding the dynamic associations between these sets of variables has implications for theory development and applied research. This was a longitudinal survey study. Participants were 180 exercisers (79 men, 101 women) from Greece, who were recruited from fitness centers and were asked to complete questionnaires assessing exercise identity (exercise beliefs and role-identity) and exercise motivation (intrinsic, identified, introjected, external motivation, and amotivation) three times within a 6 month period. Multilevel growth curve modeling examined the role of motivational regulations as within- and between-level predictors of exercise identity, and a model in which exercise identity predicted exercise motivation at the within- and between-person levels. Results showed that within-person changes in intrinsic motivation, introjected, and identified regulations were positively and reciprocally related to within-person changes in exercise beliefs; intrinsic motivation was also a positive predictor of within-person changes in role-identity but not vice versa. Between-person differences in the means of predictor variables were predictive of initial levels and average rates of change in the outcome variables. The findings show support to the proposition that a strong exercise identity (particularly exercise beliefs) can foster motivation for behaviors that reinforce this identity. We also demonstrate that such relations can be reciprocal overtime and can depend on the type of motivation in question as well as between-person differences in absolute levels of these variables. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of intrinsic motivation on affective responses during and after exercise: latent curve model analysis.

Science.gov (United States)

Shin, Myoungjin; Kim, Inwoo; Kwon, Sungho

2014-12-01

Understanding the relationship between affect and exercise is helpful in predicting human behavior with respect to exercise participation. The goals of the present study were to investigate individual differences in affective response during and after exercise and to identify the role of intrinsic motivation in affective changes. 30 active male college students (M age = 21.4 yr.) who regularly participated in sports activities volunteered to answer a questionnaire measuring intrinsic motivation toward running activities and performed a 20-min. straight running protocol at heavy intensity (about 70% of VO2max). Participants' affective responses were measured every 5 min. from the beginning of the run to 10 min. after completing the run. Latent curve model analysis indicated that individuals experienced different changes in affective state during exercise, moderated by intrinsic motivation. Higher intrinsic motivation was associated with more positive affect during exercise. There were no significant individual differences in the positive tendency of the participants' affective responses after exercise over time. Intrinsic motivation seems to facilitate positive feelings during exercise and encourages participation in exercise.

Statistical analysis of the W Cyg light curve

International Nuclear Information System (INIS)

Klyus, I.A.

1983-01-01

A statistical analysis of the light curve of W Cygni has been carried out. The process of brightness variations brightness of the star is shown to be a stationary stochastic one. The hypothesis of stationarity of the process was checked at the significance level of α=0.05. Oscillations of the brightness with average durations of 131 and 250 days have been found. It is proved that oscillations are narrow-band noise, i.e. cycles. Peaks on the power spectrum corresponding to these cycles exceed 99% confidence interval. It has been stated that the oscillations are independent

Teacher-student interpersonal relationships do change and affect academic motivation: a multilevel growth curve modelling.

Science.gov (United States)

Maulana, Ridwan; Opdenakker, Marie-Christine; Bosker, Roel

2014-09-01

Research has shown that the teacher-student interpersonal relationship (TSIR) is important for student motivation. Although TSIR has received a growing interest, there are only few studies that focus on changes and links between TSIR and student academic motivation in a longitudinal fashion in non-Western contexts. This study investigated changes in TSIR and links with academic motivation as perceived by first-grade secondary school students in Indonesia. TSIR was studied from the perspective of interpersonal behaviour in terms of Influence and Proximity. Students' academic motivation was studied from the perspective of self-determination theory. A total of 504 first-grade secondary school students of 16 mathematics and English classes participated in the study. Surveys were administered in five waves throughout the school year. Multilevel growth curve modelling was applied. Contrary to the (limited) general research findings from Western contexts, we found that the quality of TSIR (student perceptions) increased over time. The increase was slightly more pronounced for Proximity than for Influence. In accordance with the findings for the Western countries, the level of students' controlled motivation increased, while that of autonomous motivation decreased over time. However, the negative change in autonomous motivation was less pronounced. As in Western countries, TSIR was longitudinally linked with academic motivation, in particular, with autonomous motivation. Evidence is found that TSIR can change in a favourable way, and this positively affects student motivation. Future research could benefit from unravelling the influences of cultures on changes in TSIR in broader contexts. © 2013 The British Psychological Society.

The statistics of the points where nodal lines intersect a reference curve

International Nuclear Information System (INIS)

Aronovitch, Amit; Smilansky, Uzy

2007-01-01

We study the intersection points of a fixed planar curve Γ with the nodal set of a translationally invariant and isotropic Gaussian random field Ψ(r) and the zeros of its normal derivative across the curve. The intersection points form a discrete random process which is the object of this study. The field probability distribution function is completely specified by the correlation G(|r - r'|) = (Ψ(r)Ψ(r')). Given an arbitrary G(|r - r'|), we compute the two-point correlation function of the point process on the line, and derive other statistical measures (repulsion, rigidity) which characterize the short- and long-range correlations of the intersection points. We use these statistical measures to quantitatively characterize the complex patterns displayed by various kinds of nodal networks. We apply these statistics in particular to nodal patterns of random waves and of eigenfunctions of chaotic billiards. Of special interest is the observation that for monochromatic random waves, the number variance of the intersections with long straight segments grows like Lln L, as opposed to the linear growth predicted by the percolation model, which was successfully used to predict other long-range nodal properties of that field

Motivation for and Benefits from Attending the AP Statistics Reading

Science.gov (United States)

Jacobbe, Tim; Hartlaub, Bradley A.; Whitaker, Douglas

2013-01-01

This study explores the Advanced Placement® Statistics reading as a source of professional development for teachers. The study was conducted to capture the motivation for and benefits from attending the collective grading. Research has shown that examining student work during professional development has implications for teaching. The premise of…

Sparse approximation of currents for statistics on curves and surfaces.

Science.gov (United States)

Durrleman, Stanley; Pennec, Xavier; Trouvé, Alain; Ayache, Nicholas

2008-01-01

Computing, processing, visualizing statistics on shapes like curves or surfaces is a real challenge with many applications ranging from medical image analysis to computational geometry. Modelling such geometrical primitives with currents avoids feature-based approach as well as point-correspondence method. This framework has been proved to be powerful to register brain surfaces or to measure geometrical invariants. However, if the state-of-the-art methods perform efficiently pairwise registrations, new numerical schemes are required to process groupwise statistics due to an increasing complexity when the size of the database is growing. Statistics such as mean and principal modes of a set of shapes often have a heavy and highly redundant representation. We propose therefore to find an adapted basis on which mean and principal modes have a sparse decomposition. Besides the computational improvement, this sparse representation offers a way to visualize and interpret statistics on currents. Experiments show the relevance of the approach on 34 sets of 70 sulcal lines and on 50 sets of 10 meshes of deep brain structures.

StAR: a simple tool for the statistical comparison of ROC curves

Directory of Open Access Journals (Sweden)

Melo Francisco

2008-06-01

Full Text Available Abstract Background As in many different areas of science and technology, most important problems in bioinformatics rely on the proper development and assessment of binary classifiers. A generalized assessment of the performance of binary classifiers is typically carried out through the analysis of their receiver operating characteristic (ROC curves. The area under the ROC curve (AUC constitutes a popular indicator of the performance of a binary classifier. However, the assessment of the statistical significance of the difference between any two classifiers based on this measure is not a straightforward task, since not many freely available tools exist. Most existing software is either not free, difficult to use or not easy to automate when a comparative assessment of the performance of many binary classifiers is intended. This constitutes the typical scenario for the optimization of parameters when developing new classifiers and also for their performance validation through the comparison to previous art. Results In this work we describe and release new software to assess the statistical significance of the observed difference between the AUCs of any two classifiers for a common task estimated from paired data or unpaired balanced data. The software is able to perform a pairwise comparison of many classifiers in a single run, without requiring any expert or advanced knowledge to use it. The software relies on a non-parametric test for the difference of the AUCs that accounts for the correlation of the ROC curves. The results are displayed graphically and can be easily customized by the user. A human-readable report is generated and the complete data resulting from the analysis are also available for download, which can be used for further analysis with other software. The software is released as a web server that can be used in any client platform and also as a standalone application for the Linux operating system. Conclusion A new software for

Growth curve and diet density affect eating motivation, behaviour, and body composition of broiler breeders during rearing

NARCIS (Netherlands)

Mozos, de los J.; Garcia Ruiz, A.I.; Hartog, den L.A.; Villamide, M.J.

2017-01-01

The aim of this work has been to assess the effect of diet density [control (CON) or 15% diluted (DIL)] and growth curve [recommended by the genetic line (RBW) or 15% heavier (HBW)] and their interaction on BW uniformity, feeding motivation, behavior, and body composition of broiler breeder pullets.

Direct Breakthrough Curve Prediction From Statistics of Heterogeneous Conductivity Fields

Science.gov (United States)

Hansen, Scott K.; Haslauer, Claus P.; Cirpka, Olaf A.; Vesselinov, Velimir V.

2018-01-01

This paper presents a methodology to predict the shape of solute breakthrough curves in heterogeneous aquifers at early times and/or under high degrees of heterogeneity, both cases in which the classical macrodispersion theory may not be applicable. The methodology relies on the observation that breakthrough curves in heterogeneous media are generally well described by lognormal distributions, and mean breakthrough times can be predicted analytically. The log-variance of solute arrival is thus sufficient to completely specify the breakthrough curves, and this is calibrated as a function of aquifer heterogeneity and dimensionless distance from a source plane by means of Monte Carlo analysis and statistical regression. Using the ensemble of simulated groundwater flow and solute transport realizations employed to calibrate the predictive regression, reliability estimates for the prediction are also developed. Additional theoretical contributions include heuristics for the time until an effective macrodispersion coefficient becomes applicable, and also an expression for its magnitude that applies in highly heterogeneous systems. It is seen that the results here represent a way to derive continuous time random walk transition distributions from physical considerations rather than from empirical field calibration.

Statistics for products of traces of high powers of the frobenius class of hyperelliptic curves

OpenAIRE

Roditty-Gershon, Edva

2011-01-01

We study the averages of products of traces of high powers of the Frobenius class of hyperelliptic curves of genus g over a fixed finite field. We show that for increasing genus g, the limiting expectation of these products equals to the expectation when the curve varies over the unitary symplectic group USp(2g). We also consider the scaling limit of linear statistics for eigenphases of the Frobenius class of hyperelliptic curves, and show that their first few moments are Gaussian.

Principal Curves for Statistical Divergences and an Application to Finance

Directory of Open Access Journals (Sweden)

Ana Flávia P. Rodrigues

2018-05-01

Full Text Available This paper proposes a method for the beta pricing model under the consideration of non-Gaussian returns by means of a generalization of the mean-variance model and the use of principal curves to define a divergence model for the optimization of the pricing model. We rely on the q-exponential model so consider the properties of the divergences which are used to describe the statistical model and fully characterize the behavior of the assets. We derive the minimum divergence portfolio, which generalizes the Markowitz’s (mean-divergence approach and relying on the information geometrical aspects of the distributions the Capital Asset Pricing Model (CAPM is then derived under the geometrical characterization of the distributions which model the data, all by the consideration of principal curves approach. We discuss the possibility of integration of our model into an adaptive procedure that can be used for the search of optimum points on finance applications.

A Primer on the Statistical Modelling of Learning Curves in Health Professions Education

Science.gov (United States)

Pusic, Martin V.; Boutis, Kathy; Pecaric, Martin R.; Savenkov, Oleksander; Beckstead, Jason W.; Jaber, Mohamad Y.

2017-01-01

Learning curves are a useful way of representing the rate of learning over time. Features include an index of baseline performance (y-intercept), the efficiency of learning over time (slope parameter) and the maximal theoretical performance achievable (upper asymptote). Each of these parameters can be statistically modelled on an individual and…

Methods for estimating flow-duration curve and low-flow frequency statistics for ungaged locations on small streams in Minnesota

Science.gov (United States)

Ziegeweid, Jeffrey R.; Lorenz, David L.; Sanocki, Chris A.; Czuba, Christiana R.

2015-12-24

Knowledge of the magnitude and frequency of low flows in streams, which are flows in a stream during prolonged dry weather, is fundamental for water-supply planning and design; waste-load allocation; reservoir storage design; and maintenance of water quality and quantity for irrigation, recreation, and wildlife conservation. This report presents the results of a statewide study for which regional regression equations were developed for estimating 13 flow-duration curve statistics and 10 low-flow frequency statistics at ungaged stream locations in Minnesota. The 13 flow-duration curve statistics estimated by regression equations include the 0.0001, 0.001, 0.02, 0.05, 0.1, 0.25, 0.50, 0.75, 0.9, 0.95, 0.99, 0.999, and 0.9999 exceedance-probability quantiles. The low-flow frequency statistics include annual and seasonal (spring, summer, fall, winter) 7-day mean low flows, seasonal 30-day mean low flows, and summer 122-day mean low flows for a recurrence interval of 10 years. Estimates of the 13 flow-duration curve statistics and the 10 low-flow frequency statistics are provided for 196 U.S. Geological Survey continuous-record streamgages using streamflow data collected through September 30, 2012.

Statistical properties of a utility measure of observer performance compared to area under the ROC curve

Science.gov (United States)

Abbey, Craig K.; Samuelson, Frank W.; Gallas, Brandon D.; Boone, John M.; Niklason, Loren T.

2013-03-01

The receiver operating characteristic (ROC) curve has become a common tool for evaluating diagnostic imaging technologies, and the primary endpoint of such evaluations is the area under the curve (AUC), which integrates sensitivity over the entire false positive range. An alternative figure of merit for ROC studies is expected utility (EU), which focuses on the relevant region of the ROC curve as defined by disease prevalence and the relative utility of the task. However if this measure is to be used, it must also have desirable statistical properties keep the burden of observer performance studies as low as possible. Here, we evaluate effect size and variability for EU and AUC. We use two observer performance studies recently submitted to the FDA to compare the EU and AUC endpoints. The studies were conducted using the multi-reader multi-case methodology in which all readers score all cases in all modalities. ROC curves from the study were used to generate both the AUC and EU values for each reader and modality. The EU measure was computed assuming an iso-utility slope of 1.03. We find mean effect sizes, the reader averaged difference between modalities, to be roughly 2.0 times as big for EU as AUC. The standard deviation across readers is roughly 1.4 times as large, suggesting better statistical properties for the EU endpoint. In a simple power analysis of paired comparison across readers, the utility measure required 36% fewer readers on average to achieve 80% statistical power compared to AUC.

Statistical reexamination of analytical method on the observed electron spin (or nuclear) resonance curves

International Nuclear Information System (INIS)

Kim, J.W.

1980-01-01

Observed magnetic resonance curves are statistically reexamined. Typical models of resonance lines are Lorentzian and Gaussian distribution functions. In the case of metallic, alloy or intermetallic compound samples, observed resonance lines are supperposed with the absorption line and the dispersion line. The analyzing methods of supperposed resonance lines are demonstrated. (author)

MOTIVATION TO STUDY – STUDENTS` MOTIVATIONAL RESPONSE ON VARIOUS MOTIVATIONAL ACTIONS IN STATISTICAL COURSES

Directory of Open Access Journals (Sweden)

Pacáková, Zuzana

2013-12-01

Full Text Available Motivation to study is a topic to be studied on various levels of educational process, although the methods to be used can be very different. We have examined the motivational response of university students on various motivational actions. Credit tests results of a sample of Business and Administration study programme students from the period 2009/10 to 2012/13 were analyzed. During this period several motivational actions were accepted. The most important one was a chance to pass the exam on the basis of credit tests results only, if given 15 or more points from maximum of 20 points. On the other hand the students were given less tries to finish the test. It was found an increase in mean point results especially in the winter term. There is also an increasing percentage of students able to pass the test on the first attempt and increasing proportion of students who are given exam grade on the basis of the credit tests results. Therefore it can be assumed, that motivation in a form of possibility to be given the exam grade on the basis of credit tests, is very strong.

Microvariability in AGNs: study of different statistical methods - I. Observational analysis

Science.gov (United States)

Zibecchi, L.; Andruchow, I.; Cellone, S. A.; Carpintero, D. D.; Romero, G. E.; Combi, J. A.

2017-05-01

We present the results of a study of different statistical methods currently used in the literature to analyse the (micro)variability of active galactic nuclei (AGNs) from ground-based optical observations. In particular, we focus on the comparison between the results obtained by applying the so-called C and F statistics, which are based on the ratio of standard deviations and variances, respectively. The motivation for this is that the implementation of these methods leads to different and contradictory results, making the variability classification of the light curves of a certain source dependent on the statistics implemented. For this purpose, we re-analyse the results on an AGN sample observed along several sessions with the 2.15 m 'Jorge Sahade' telescope (CASLEO), San Juan, Argentina. For each AGN, we constructed the nightly differential light curves. We thus obtained a total of 78 light curves for 39 AGNs, and we then applied the statistical tests mentioned above, in order to re-classify the variability state of these light curves and in an attempt to find the suitable statistical methodology to study photometric (micro)variations. We conclude that, although the C criterion is not proper a statistical test, it could still be a suitable parameter to detect variability and that its application allows us to get more reliable variability results, in contrast with the F test.

Learning Curves and Bootstrap Estimates for Inference with Gaussian Processes: A Statistical Mechanics Study

DEFF Research Database (Denmark)

Malzahn, Dorthe; Opper, Manfred

2003-01-01

We employ the replica method of statistical physics to study the average case performance of learning systems. The new feature of our theory is that general distributions of data can be treated, which enables applications to real data. For a class of Bayesian prediction models which are based...... on Gaussian processes, we discuss Bootstrap estimates for learning curves....

Using Fun in the Statistics Classroom: An Exploratory Study of College Instructors' Hesitations and Motivations

Science.gov (United States)

Lesser, Lawrence M.; Wall, Amitra A.; Carver, Robert H.; Pearl, Dennis K.; Martin, Nadia; Kuiper, Shonda; Posner, Michael A.; Erickson, Patricia; Liao, Shu-Min; Albert, Jim; Weber, John J., III

2013-01-01

This study examines statistics instructors' use of fun as well as their motivations, hesitations, and awareness of resources. In 2011, a survey was administered to attendees at a national statistics education conference, and follow-up qualitative interviews were conducted with 16 of those ("N" = 249) surveyed to provide further…

Statistical inference methods for two crossing survival curves: a comparison of methods.

Science.gov (United States)

Li, Huimin; Han, Dong; Hou, Yawen; Chen, Huilin; Chen, Zheng

2015-01-01

A common problem that is encountered in medical applications is the overall homogeneity of survival distributions when two survival curves cross each other. A survey demonstrated that under this condition, which was an obvious violation of the assumption of proportional hazard rates, the log-rank test was still used in 70% of studies. Several statistical methods have been proposed to solve this problem. However, in many applications, it is difficult to specify the types of survival differences and choose an appropriate method prior to analysis. Thus, we conducted an extensive series of Monte Carlo simulations to investigate the power and type I error rate of these procedures under various patterns of crossing survival curves with different censoring rates and distribution parameters. Our objective was to evaluate the strengths and weaknesses of tests in different situations and for various censoring rates and to recommend an appropriate test that will not fail for a wide range of applications. Simulation studies demonstrated that adaptive Neyman's smooth tests and the two-stage procedure offer higher power and greater stability than other methods when the survival distributions cross at early, middle or late times. Even for proportional hazards, both methods maintain acceptable power compared with the log-rank test. In terms of the type I error rate, Renyi and Cramér-von Mises tests are relatively conservative, whereas the statistics of the Lin-Xu test exhibit apparent inflation as the censoring rate increases. Other tests produce results close to the nominal 0.05 level. In conclusion, adaptive Neyman's smooth tests and the two-stage procedure are found to be the most stable and feasible approaches for a variety of situations and censoring rates. Therefore, they are applicable to a wider spectrum of alternatives compared with other tests.

Curve Boxplot: Generalization of Boxplot for Ensembles of Curves.

Science.gov (United States)

Mirzargar, Mahsa; Whitaker, Ross T; Kirby, Robert M

2014-12-01

In simulation science, computational scientists often study the behavior of their simulations by repeated solutions with variations in parameters and/or boundary values or initial conditions. Through such simulation ensembles, one can try to understand or quantify the variability or uncertainty in a solution as a function of the various inputs or model assumptions. In response to a growing interest in simulation ensembles, the visualization community has developed a suite of methods for allowing users to observe and understand the properties of these ensembles in an efficient and effective manner. An important aspect of visualizing simulations is the analysis of derived features, often represented as points, surfaces, or curves. In this paper, we present a novel, nonparametric method for summarizing ensembles of 2D and 3D curves. We propose an extension of a method from descriptive statistics, data depth, to curves. We also demonstrate a set of rendering and visualization strategies for showing rank statistics of an ensemble of curves, which is a generalization of traditional whisker plots or boxplots to multidimensional curves. Results are presented for applications in neuroimaging, hurricane forecasting and fluid dynamics.

Statistically generated weighted curve fit of residual functions for modal analysis of structures

Science.gov (United States)

Bookout, P. S.

1995-01-01

A statistically generated weighting function for a second-order polynomial curve fit of residual functions has been developed. The residual flexibility test method, from which a residual function is generated, is a procedure for modal testing large structures in an external constraint-free environment to measure the effects of higher order modes and interface stiffness. This test method is applicable to structures with distinct degree-of-freedom interfaces to other system components. A theoretical residual function in the displacement/force domain has the characteristics of a relatively flat line in the lower frequencies and a slight upward curvature in the higher frequency range. In the test residual function, the above-mentioned characteristics can be seen in the data, but due to the present limitations in the modal parameter evaluation (natural frequencies and mode shapes) of test data, the residual function has regions of ragged data. A second order polynomial curve fit is required to obtain the residual flexibility term. A weighting function of the data is generated by examining the variances between neighboring data points. From a weighted second-order polynomial curve fit, an accurate residual flexibility value can be obtained. The residual flexibility value and free-free modes from testing are used to improve a mathematical model of the structure. The residual flexibility modal test method is applied to a straight beam with a trunnion appendage and a space shuttle payload pallet simulator.

Statistical study of clone survival curves after irradiation in one or two stages. Comparison and generalization of different models

International Nuclear Information System (INIS)

Lachet, Bernard.

1975-01-01

A statistical study was carried out on 208 survival curves for chlorella subjected to γ or particle radiations. The computing programmes used were written in Fortran. The different experimental causes contributing to the variance of a survival rate are analyzed and consequently the experiments can be planned. Each curve was fitted to four models by the weighted least squares method applied to non-linear functions. The validity of the fits obtained can be checked by the F test. It was possible to define the confidence and prediction zones around an adjusted curve by weighting of the residual variance, in spite of error on the doses delivered; the confidence limits can them be fixed for a dose estimated from an exact or measured survival. The four models adopted were compared for the precision of their fit (by a non-parametric simultaneous comparison test) and the scattering of their adjusted parameters: Wideroe's model gives a very good fit with the experimental points in return for a scattering of its parameters, which robs them of their presumed meaning. The principal component analysis showed the statistical equivalence of the 1 and 2 hit target models. Division of the irradiation into two doses, the first fixed by the investigator, leads to families of curves for which the equation was established from that of any basic model expressing the dose survival relationship in one-stage irradiation [fr

Gender and Facebook motives as predictors of specific types of Facebook use: A latent growth curve analysis in adolescence.

Science.gov (United States)

Frison, Eline; Eggermont, Steven

2016-10-01

Despite increasing evidence that specific types of Facebook use (i.e., active private, active public, and passive Facebook use) are differently related to adolescents' well-being, little is known how these types function over the course of adolescence and whether gender and Facebook motives may predict the initial level and changes in these types over time. To address these gaps, Flemish adolescents (ages 12-19) were questioned at three different time points, with six months in between (NTime1 = 1866). Latent growth curve models revealed that active private Facebook use increased over the course of adolescence, whereas public Facebook use decreased. Passive Facebook use, however, remained stable. In addition, gender and Facebook motives were related to initial levels of specific types of Facebook use, and predictive of dynamic change in specific types of Facebook use over time. The discussion focuses on the understanding and implications of these findings. Copyright © 2016. Published by Elsevier Ltd.

Stochastic or statistic? Comparing flow duration curve models in ungauged basins and changing climates

Science.gov (United States)

Müller, M. F.; Thompson, S. E.

2015-09-01

The prediction of flow duration curves (FDCs) in ungauged basins remains an important task for hydrologists given the practical relevance of FDCs for water management and infrastructure design. Predicting FDCs in ungauged basins typically requires spatial interpolation of statistical or model parameters. This task is complicated if climate becomes non-stationary, as the prediction challenge now also requires extrapolation through time. In this context, process-based models for FDCs that mechanistically link the streamflow distribution to climate and landscape factors may have an advantage over purely statistical methods to predict FDCs. This study compares a stochastic (process-based) and statistical method for FDC prediction in both stationary and non-stationary contexts, using Nepal as a case study. Under contemporary conditions, both models perform well in predicting FDCs, with Nash-Sutcliffe coefficients above 0.80 in 75 % of the tested catchments. The main drives of uncertainty differ between the models: parameter interpolation was the main source of error for the statistical model, while violations of the assumptions of the process-based model represented the main source of its error. The process-based approach performed better than the statistical approach in numerical simulations with non-stationary climate drivers. The predictions of the statistical method under non-stationary rainfall conditions were poor if (i) local runoff coefficients were not accurately determined from the gauge network, or (ii) streamflow variability was strongly affected by changes in rainfall. A Monte Carlo analysis shows that the streamflow regimes in catchments characterized by a strong wet-season runoff and a rapid, strongly non-linear hydrologic response are particularly sensitive to changes in rainfall statistics. In these cases, process-based prediction approaches are strongly favored over statistical models.

Changes in teachers' involvement versus rejection and links with academic motivation during the first year of secondary education: a multilevel growth curve analysis.

Science.gov (United States)

Maulana, Ridwan; Opdenakker, Marie-Christine; Stroet, Kim; Bosker, Roel

2013-09-01

Research consistently shows that the learning environment plays an important role for early adolescents' learning and outcomes and suggests that good teacher-student relationships can serve as a protective factor for maintaining young adolescents' interest and active engagement in learning. However, less is known about the dynamic nature of teacher-student relationships and how they link with academic motivation development. Furthermore, little is known about the nature and the effects of teacher-student relationships in a cross-national context. The present study investigated changes in two components of teacher-student relationships (teachers' involvement vs. rejection) and examined links with students' academic motivation during the first grade of secondary school. Ten Dutch and ten Indonesian teachers (65 % female) from 24 classes were videoed 12 times across the school year, and four videos for each class were selected randomly and coded on teachers' involvement versus rejection. A total of 713 students (52 % girls) completed four-wave measures of their academic motivation after each video observation. Multilevel growth curve modeling revealed that the teacher's involvement changed in a curvilinear way and decreased across the first year of secondary education, while changes in the teacher's rejection did not follow a linear time function. Academic motivation changed in an undesirable way: controlled motivation increased, while autonomous motivation decreased over time. Teachers' involvement had a unique contribution in preventing high levels of controlled motivation in both countries. Findings suggest that teacher-student relationships (teachers' involvement) play an essential role in early adolescents' motivation regardless of the nations and should be a priority for schools.

Statistical evaluation of low cycle loading curves parameters for structural materials by mechanical characteristics

International Nuclear Information System (INIS)

Daunys, Mykolas; Sniuolis, Raimondas

2006-01-01

About 300 welded joint materials that are used in nuclear power energy were tested under monotonous tension and low cycle loading in Kaunas University of Technology together with St. Peterburg Central Research Institute of Structural Materials in 1970-2000. The main mechanical, low cycle loading and fracture characteristics of base metals, weld metals and some heat-affected zones of welded joints metals were determined during these experiments. Analytical dependences of low cycle fatigue parameters on mechanical characteristics of structural materials were proposed on the basis of a large number of experimental data, obtained by the same methods and testing equipment. When these dependences are used, expensive low cycle fatigue tests may be omitted and it is possible to compute low cycle loading curves parameters and lifetime for structural materials according to the main mechanical characteristics given in technical manuals. Dependences of low cycle loading curves parameters on mechanical characteristics for several groups of structural materials used in Russian nuclear power energy are obtained by statistical methods and proposed in this paper

Statistics about elliptic curves over finite prime fields

OpenAIRE

Gekeler, Ernst-Ulrich

2006-01-01

We derive formulas for the probabilities of various properties (cyclicity, squarefreeness, generation by random points) of the point groups of randomly chosen elliptic curves over random prime fields.

The measurement of employee motivation by using multi-factor statistical analysis

OpenAIRE

Zámečník, Roman

2014-01-01

The proposal and implementation of an effective motivation program is one of the key management tasks of a company. Improperly designed and applied motivation programs can have a negative impact on employees, who are not motivated to achieve maximum performance. The paper will also deal with the problems of employee motivation and the motivation programs in a selected industrial company. The motivation structure analysis will be based on the general knowledge of the theory of motivation, toge...

Motivation, values, and work design as drivers of participation in the R open source project for statistical computing.

Science.gov (United States)

Mair, Patrick; Hofmann, Eva; Gruber, Kathrin; Hatzinger, Reinhold; Zeileis, Achim; Hornik, Kurt

2015-12-01

One of the cornerstones of the R system for statistical computing is the multitude of packages contributed by numerous package authors. This amount of packages makes an extremely broad range of statistical techniques and other quantitative methods freely available. Thus far, no empirical study has investigated psychological factors that drive authors to participate in the R project. This article presents a study of R package authors, collecting data on different types of participation (number of packages, participation in mailing lists, participation in conferences), three psychological scales (types of motivation, psychological values, and work design characteristics), and various socio-demographic factors. The data are analyzed using item response models and subsequent generalized linear models, showing that the most important determinants for participation are a hybrid form of motivation and the social characteristics of the work design. Other factors are found to have less impact or influence only specific aspects of participation.

RMS fatigue curves for random vibrations

International Nuclear Information System (INIS)

Brenneman, B.; Talley, J.G.

1984-01-01

Fatigue usage factors for deterministic or constant amplitude vibration stresses may be calculated with well known procedures and fatigue curves given in the ASME Boiler and Pressure Vessel Code. However, some phenomena produce nondeterministic cyclic stresses which can only be described and analyzed with statistical concepts and methods. Such stresses may be caused by turbulent fluid flow over a structure. Previous methods for solving this statistical fatigue problem are often difficult to use and may yield inaccurate results. Two such methods examined herein are Crandall's method and the ''3sigma'' method. The objective of this paper is to provide a method for creating ''RMS fatigue curves'' which accurately incorporate the requisite statistical information. These curves are given and may be used by analysts with the same ease and in the same manner as the ASME fatigue curves

Statistical properties of curved polymer

Indian Academy of Sciences (India)

respective ground states decide the conformational statistics of the polymer. For semiflexible polymers, the relevant non-dimensional quantity is lp/L, where lp is the persistence length (which is proportional to the bending modulus k) and L is the contour length of the polymer. In the limit, lp/L ≪ 1, the polymer behaves as.

Growth curve and diet density affect eating motivation, behavior, and body composition of broiler breeders during rearing.

Science.gov (United States)

de Los Mozos, J; García-Ruiz, A I; den Hartog, L A; Villamide, M J

2017-08-01

The aim of this work has been to assess the effect of diet density [control (CON) or 15% diluted (DIL)] and growth curve [recommended by the genetic line (RBW) or 15% heavier (HBW)] and their interaction on BW uniformity, feeding motivation, behavior, and body composition of broiler breeder pullets. A total of 3,000 one-day-old female breeders Ross 308, distributed in 20 pens, was randomly assigned to each treatment. Feed allowance was weekly adjusted to reach the desired BW. Feed was provided as pelleted (zero to 3 wk) and crumble (4 to 19 wk). Time eating was measured at 7, 11, and 19 weeks. A feeding rate test was performed after 11 weeks. Behavior was observed at 9 and 15 wk, by visual scan. At 6, 13, and 19 wk of age, one bird/pen was slaughtered for weighing different organs and analyzing the composition of empty whole bodies. Treatments did not affect BW uniformity; relative weights of the ovary, oviduct, or gizzard; or protein content of empty BW. Time eating varied with the growth curve at 19 wk (P motivation. Behavior was affected by the age and by the time of the d measured, but it did not change with the treatments. Birds spent most time pecking objects (50%), feeding (28%), and drinking (17%). Pullets fed DIL had 8% lower breast yield at different ages and higher empty digestive tracts at 6 weeks. Body composition varied with age; fat content increased from 12.7 to 15.9 to 19.8% for 6, 13, and 19 wk, respectively. The lowest body fat was observed for RBW pullets fed DIL (P = 0.003) at 19 weeks. Feeding DIL diets to HBW pullets could be done to increase the time spent eating and reduce their feeling of hunger without negative effects on body composition. However, its influence on behavior and BW uniformity was not proved. © The Author 2017. Published by Oxford University Press on behalf of Poultry Science Association.

Systematic review of learning curves for minimally invasive abdominal surgery: a review of the methodology of data collection, depiction of outcomes, and statistical analysis.

Science.gov (United States)

Harrysson, Iliana J; Cook, Jonathan; Sirimanna, Pramudith; Feldman, Liane S; Darzi, Ara; Aggarwal, Rajesh

2014-07-01

To determine how minimally invasive surgical learning curves are assessed and define an ideal framework for this assessment. Learning curves have implications for training and adoption of new procedures and devices. In 2000, a review of the learning curve literature was done by Ramsay et al and it called for improved reporting and statistical evaluation of learning curves. Since then, a body of literature is emerging on learning curves but the presentation and analysis vary. A systematic search was performed of MEDLINE, EMBASE, ISI Web of Science, ERIC, and the Cochrane Library from 1985 to August 2012. The inclusion criteria are minimally invasive abdominal surgery formally analyzing the learning curve and English language. 592 (11.1%) of the identified studies met the selection criteria. Time is the most commonly used proxy for the learning curve (508, 86%). Intraoperative outcomes were used in 316 (53%) of the articles, postoperative outcomes in 306 (52%), technical skills in 102 (17%), and patient-oriented outcomes in 38 (6%) articles. Over time, there was evidence of an increase in the relative amount of laparoscopic and robotic studies (P statistical evidence of a change in the complexity of analysis (P = 0.121). Assessment of learning curves is needed to inform surgical training and evaluate new clinical procedures. An ideal analysis would account for the degree of complexity of individual cases and the inherent differences between surgeons. There is no single proxy that best represents the success of surgery, and hence multiple outcomes should be collected.

Students’ perception of frequent assessments and its relation to motivation and grades in a statistics course: a pilot study

NARCIS (Netherlands)

Vaessen, B.E.; van den Beemt, A.A.J.; van de Watering, G.A.; van Meeuwen, L.W.; Lemmens, A.M.C.; den Brok, P.J.

2017-01-01

This pilot study measures university students’ perceptions of graded frequent assessments in an obligatory statistics course using a novel questionnaire. Relations between perceptions of frequent assessments, intrinsic motivation and grades were also investigated. A factor analysis of the

Motivation, values, and work design as drivers of participation in the R open source project for statistical computing

Science.gov (United States)

Mair, Patrick; Hofmann, Eva; Gruber, Kathrin; Hatzinger, Reinhold; Zeileis, Achim; Hornik, Kurt

2015-01-01

One of the cornerstones of the R system for statistical computing is the multitude of packages contributed by numerous package authors. This amount of packages makes an extremely broad range of statistical techniques and other quantitative methods freely available. Thus far, no empirical study has investigated psychological factors that drive authors to participate in the R project. This article presents a study of R package authors, collecting data on different types of participation (number of packages, participation in mailing lists, participation in conferences), three psychological scales (types of motivation, psychological values, and work design characteristics), and various socio-demographic factors. The data are analyzed using item response models and subsequent generalized linear models, showing that the most important determinants for participation are a hybrid form of motivation and the social characteristics of the work design. Other factors are found to have less impact or influence only specific aspects of participation. PMID:26554005

A Semiautomatic Pipeline for Be Star Light Curves

Science.gov (United States)

Rímulo, L. R.; Carciofi, A. C.; Rivinius, T.; Okazaki, A.

2016-11-01

Observational and theoretical studies from the last decade have shown that the Viscous Decretion Disk (VDD) scenario, in which turbulent viscosity is the physical mechanism responsible for the transport of material and angular momentum ejected from the star to the outer regions of the disk, is the only viable model for explaining the circumstellar disks of Be stars. In the α-disk approach applied to the VDD, the dimensionless parameter α is a measure of the turbulent viscosity. Recently, combining the time-dependent evolution of a VDD α-disk with non-LTE radiative transfer calculations, the first measurement of the α parameter was made, for the disk dissipation of the Be star ω CMa. It was found that α≍ 1 for that Be disk. The main motivation of this present work is the statistical determination of the α parameter. For this purpose, we present a pipeline that will allow the semiautomatic determination of the α parameter of several dozens of light curves of Be stars available from photometric surveys, In this contribution, we describe the pipeline, outlining the main staps required for the semiautomatic analysis of light curves

The Prompt-afterglow Connection in Gamma-ray Bursts: a Comprehensive Statistical Analysis of Swift X-ray Light-curves

Science.gov (United States)

Margutti, R.; Zaninoni, E.; Bernardini, M. G.; Chincarini, G.; Pasotti, F.; Guidorzi, C.; Angelini, Lorella; Burrows, D. N.; Capalbi, M.; Evans, P. A.;

A new method for curve fitting to the data with low statistics not using the chi2-method

International Nuclear Information System (INIS)

Awaya, T.

1979-01-01

A new method which does not use the chi 2 -fitting method is investigated in order to fit the theoretical curve to data with low statistics. The method is compared with the usual and modified chi 2 -fitting ones. The analyses are done for data which are generated by computers. It is concluded that the new method gives good results in all the cases. (Auth.)

MOTIVATION AND MOTIVES - DRIVER AND REASON OF CONSUMER'S BUYING BEHAVIOR

OpenAIRE

TICHINDELEAN Mihai; VINEREAN Simona

2013-01-01

The purpose of the paper is to understand and measure consumer's motives as part of the complex mental structure which has as result a certain buying behavior. To achieve this goal, the authors structured the paper in two parts: the first part contains a literature review regarding the concepts of motivation and motives, while the second part tries to measure and explain several dimensions of buying motives by using a statistical analysis tool - exploratory factor analysis.

Twisted Vector Bundles on Pointed Nodal Curves

Indian Academy of Sciences (India)

Abstract. Motivated by the quest for a good compactification of the moduli space of -bundles on a nodal curve we establish a striking relationship between Abramovich's and Vistoli's twisted bundles and Gieseker vector bundles.

A Latent Curve Model of Parental Motivational Practices and Developmental Decline in Math and Science Academic Intrinsic Motivation

Science.gov (United States)

Gottfried, Adele Eskeles; Marcoulides, George A.; Gottfried, Allen W.; Oliver, Pamella H.

2009-01-01

A longitudinal approach was used to examine the effects of parental task-intrinsic and task-extrinsic motivational practices on academic intrinsic motivation in the subject areas of math and science. Parental task-intrinsic practices comprise encouragement of children's pleasure and engagement in the learning process, whereas task-extrinsic…

Comparing statistical and process-based flow duration curve models in ungauged basins and changing rain regimes

Science.gov (United States)

Müller, M. F.; Thompson, S. E.

2016-02-01

The prediction of flow duration curves (FDCs) in ungauged basins remains an important task for hydrologists given the practical relevance of FDCs for water management and infrastructure design. Predicting FDCs in ungauged basins typically requires spatial interpolation of statistical or model parameters. This task is complicated if climate becomes non-stationary, as the prediction challenge now also requires extrapolation through time. In this context, process-based models for FDCs that mechanistically link the streamflow distribution to climate and landscape factors may have an advantage over purely statistical methods to predict FDCs. This study compares a stochastic (process-based) and statistical method for FDC prediction in both stationary and non-stationary contexts, using Nepal as a case study. Under contemporary conditions, both models perform well in predicting FDCs, with Nash-Sutcliffe coefficients above 0.80 in 75 % of the tested catchments. The main drivers of uncertainty differ between the models: parameter interpolation was the main source of error for the statistical model, while violations of the assumptions of the process-based model represented the main source of its error. The process-based approach performed better than the statistical approach in numerical simulations with non-stationary climate drivers. The predictions of the statistical method under non-stationary rainfall conditions were poor if (i) local runoff coefficients were not accurately determined from the gauge network, or (ii) streamflow variability was strongly affected by changes in rainfall. A Monte Carlo analysis shows that the streamflow regimes in catchments characterized by frequent wet-season runoff and a rapid, strongly non-linear hydrologic response are particularly sensitive to changes in rainfall statistics. In these cases, process-based prediction approaches are favored over statistical models.

A Monte Carlo Study of the Effect of Item Characteristic Curve Estimation on the Accuracy of Three Person-Fit Statistics

Science.gov (United States)

St-Onge, Christina; Valois, Pierre; Abdous, Belkacem; Germain, Stephane

2009-01-01

To date, there have been no studies comparing parametric and nonparametric Item Characteristic Curve (ICC) estimation methods on the effectiveness of Person-Fit Statistics (PFS). The primary aim of this study was to determine if the use of ICCs estimated by nonparametric methods would increase the accuracy of item response theory-based PFS for…

Phonon dispersion curves for CsCN

International Nuclear Information System (INIS)

Gaur, N.K.; Singh, Preeti; Rini, E.G.; Galgale, Jyostna; Singh, R.K.

2004-01-01

The motivation for the present work was gained from the recent publication on phonon dispersion curves (PDCs) of CsCN from the neutron scattering technique. We have applied the extended three-body force shell model (ETSM) by incorporating the effect of coupling between the translation modes and the orientation of cyanide molecules for the description of phonon dispersion curves of CsCN between the temperatures 195 and 295 K. Our results on PDCs in symmetric direction are in good agreement with the experimental data measured with inelastic neutron scattering technique. (author)

Ethnicity, Effort, Self-Efficacy, Worry, and Statistics Achievement in Malaysia: A Construct Validation of the State-Trait Motivation Model

Science.gov (United States)

Awang-Hashim, Rosa; O'Neil, Harold F., Jr.; Hocevar, Dennis

2002-01-01

The relations between motivational constructs, effort, self-efficacy and worry, and statistics achievement were investigated in a sample of 360 undergraduates in Malaysia. Both trait (cross-situational) and state (task-specific) measures of each construct were used to test a mediational trait (r) state (r) performance (TSP) model. As hypothesized,…

[The life cycle of general practitioners' professional motivations: the case of prevention].

Science.gov (United States)

Videau, Y; Batifoulier, P; Arrighi, Y; Gadreau, M; Ventelou, B

2010-10-01

The analysis of "professional motivations", mainly through the possible crowding-out effects between extrinsic and intrinsic motivations, has become an issue of great concern in the economic literature. This paper aims at applying this topic to the healthcare professions where the proper scaling up of pay-for-performance (P4P) policies by public authorities is at stake. We used a panel of 528 self-employed general practitioners in the "Provence-Alpes-Côte d'Azur" region in France to provide an interpersonal statistical decomposition between extrinsic and intrinsic motivations with regard to preventive actions. Then, we applied a Tobit model in order to specify the main explicative variables of the share of intrinsic motivations entering into physicians' total motivations. The relative share of intrinsic motivations was quite high among physicians paid with fixed fees. We found a significant effect of age on intrinsic motivations describing a U-shaped curve which can be interpreted as being the result of a "life cycle of medical motivations" or a generational effect. The cross-sectional nature of the data does not allow us to draw any conclusions concerning the predominance of the generational effect or the "life cycle effect" on the evolution of the relative share of physician's intrinsic motivations. Nevertheless, the U-shaped relation between intrinsic motivations and age questions the suitability of using uniformly P4P mechanisms. The generations or age groups of self-employed physicians who seem to be less responsive to extrinsic motivations are more likely to favour the introduction of other types of payment schemes (capitation or salary systems) or regulation tools such as clinical practice guidelines. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Motivational control of behavior of the staff

Directory of Open Access Journals (Sweden)

Лариса Григорьевна Миляева

2015-07-01

Full Text Available The article discusses the need for transition to the non-traditional (motivational concept of management of behavior of the staff; substantiates the urgent need to develop a universal innovative approach to the classification of staff to ensure the implementation of motivational models; the original technique based on the separation of employees on the conventional categories and drafting motivation curve; introduce and analyze the results of the pilot of approbation of the author's methodological approach.

a new approach of Analysing GRB light curves

International Nuclear Information System (INIS)

Varga, B.; Horvath, I.

2005-01-01

We estimated the T xx quantiles of the cumulative GRB light curves using our recalculated background. The basic information of the light curves was extracted by multivariate statistical methods. The possible classes of the light curves are also briefly discussed

Comparison and evaluation of mathematical lactation curve ...

African Journals Online (AJOL)

p2492989

A mathematical model of the lactation curve provides summary information about culling and milking strategies ..... Table 2 Statistics of the edited data for first lactation Holstein cows ..... Application of different models to the lactation curves of.

Utility of Interobserver Agreement Statistics in Establishing Radiology Resident Learning Curves During Self-directed Radiologic Anatomy Training.

Science.gov (United States)

Tureli, Derya; Altas, Hilal; Cengic, Ismet; Ekinci, Gazanfer; Baltacioglu, Feyyaz

2015-10-01

The aim of the study was to ascertain the learning curves for the radiology residents when first introduced to an anatomic structure in magnetic resonance images (MRI) to which they have not been previously exposed to. The iliolumbar ligament is a good marker for testing learning curves of radiology residents because the ligament is not part of a routine lumbar MRI reporting and has high variability in detection. Four radiologists, three residents without previous training and one mentor, studied standard axial T1- and T2-weighted images of routine lumbar MRI examinations. Radiologists had to define iliolumbar ligament while blinded to each other's findings. Interobserver agreement analyses, namely Cohen and Fleiss κ statistics, were performed for groups of 20 cases to evaluate the self-learning curve of radiology residents. Mean κ values of resident-mentor pairs were 0.431, 0.608, 0.604, 0.826, and 0.963 in the analysis of successive groups (P 0.8). Therefore, a junior radiology resident can obtain enough experience in identifying a rather ambiguous anatomic structure in routine MRI after a brief instruction of a few minutes by a mentor and studying approximately 80 cases by oneself. Implementing this methodology will help radiology educators obtain more concrete ideas on the optimal time and effort required for supported self-directed visual learning processes in resident education. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

The Effectiveness of Motivation Training for Increasing Students’ Motivation

Directory of Open Access Journals (Sweden)

Fatwa Tentama

2014-09-01

Full Text Available Students’ low level of motivation becomes a matter of concern to be addressed immediately. Students' motivation needs to be improved as it is a factor that will affect their lives in the future. This study aims to observe or examine the effectiveness of motivation training in increasing students' motivation.The research method used was the pre-experiment with one group pre-test post-test design. The subjects of this study were 15 boy and girl students of Grade X of SMK who had a low level of motivation. The measuring instruments were the motivation scales given during the pre-test and post-test. The quantitative data were statistically analyzed using the Wilcoxon test with non-parametric measurements to determine the significance of difference in the motivation level before and after the training. The data were tested using SPSS 17.0 for Windows.The result of Wilcoxon analysis to test the hypothesis whether there is a difference between the pre-test and post-test of students' motivation showed that the p = 0.025 (p < 0.05. This means that there was a significant difference between the motivation before the treatment (pre-test and after the treatment (post-test, which indicated that the students' motivation increased after a treatment in the form of motivation training.

Statistics of Smoothed Cosmic Fields in Perturbation Theory. I. Formulation and Useful Formulae in Second-Order Perturbation Theory

Science.gov (United States)

Matsubara, Takahiko

2003-02-01

We formulate a general method for perturbative evaluations of statistics of smoothed cosmic fields and provide useful formulae for application of the perturbation theory to various statistics. This formalism is an extensive generalization of the method used by Matsubara, who derived a weakly nonlinear formula of the genus statistic in a three-dimensional density field. After describing the general method, we apply the formalism to a series of statistics, including genus statistics, level-crossing statistics, Minkowski functionals, and a density extrema statistic, regardless of the dimensions in which each statistic is defined. The relation between the Minkowski functionals and other geometrical statistics is clarified. These statistics can be applied to several cosmic fields, including three-dimensional density field, three-dimensional velocity field, two-dimensional projected density field, and so forth. The results are detailed for second-order theory of the formalism. The effect of the bias is discussed. The statistics of smoothed cosmic fields as functions of rescaled threshold by volume fraction are discussed in the framework of second-order perturbation theory. In CDM-like models, their functional deviations from linear predictions plotted against the rescaled threshold are generally much smaller than that plotted against the direct threshold. There is still a slight meatball shift against rescaled threshold, which is characterized by asymmetry in depths of troughs in the genus curve. A theory-motivated asymmetry factor in the genus curve is proposed.

Irregular conformal block, spectral curve and flow equations

International Nuclear Information System (INIS)

Choi, Sang Kwan; Rim, Chaiho; Zhang, Hong

2016-01-01

Irregular conformal block is motivated by the Argyres-Douglas type of N=2 super conformal gauge theory. We investigate the classical/NS limit of irregular conformal block using the spectral curve on a Riemann surface with irregular punctures, which is equivalent to the loop equation of irregular matrix model. The spectral curve is reduced to the second order (Virasoro symmetry, SU(2) for the gauge theory) and third order (W_3 symmetry, SU(3)) differential equations of a polynomial with finite degree. The conformal and W symmetry generate the flow equations in the spectral curve and determine the irregular conformal block, hence the partition function of the Argyres-Douglas theory ala AGT conjecture.

Relationship between academic motivation and mathematics achievement among Indian adolescents in Canada and India.

Science.gov (United States)

Areepattamannil, Shaljan

2014-01-01

This study examined the relationships between academic motivation-intrinsic motivation, extrinsic motivation, amotivation-and mathematics achievement among 363 Indian adolescents in India and 355 Indian immigrant adolescents in Canada. Results of hierarchical multiple regression analyses showed that intrinsic motivation, extrinsic motivation, and amotivation were not statistically significantly related to mathematics achievement among Indian adolescents in India. In contrast, both intrinsic motivation and extrinsic motivation were statistically significantly related to mathematics achievement among Indian immigrant adolescents in Canada. While intrinsic motivation was a statistically significant positive predictor of mathematics achievement among Indian immigrant adolescents in Canada, extrinsic motivation was a statistically significant negative predictor of mathematics achievement among Indian immigrant adolescents in Canada. Amotivation was not statistically significantly related to mathematics achievement among Indian immigrant adolescents in Canada. Implications of the findings for pedagogy and practice are discussed.

Tucker tensor analysis of Matern functions in spatial statistics

KAUST Repository

Litvinenko, Alexander

2018-04-20

Low-rank Tucker tensor methods in spatial statistics 1. Motivation: improve statistical models 2. Motivation: disadvantages of matrices 3. Tools: Tucker tensor format 4. Tensor approximation of Matern covariance function via FFT 5. Typical statistical operations in Tucker tensor format 6. Numerical experiments

Learning from uncertain curves

DEFF Research Database (Denmark)

Mallasto, Anton; Feragen, Aasa

2017-01-01

We introduce a novel framework for statistical analysis of populations of nondegenerate Gaussian processes (GPs), which are natural representations of uncertain curves. This allows inherent variation or uncertainty in function-valued data to be properly incorporated in the population analysis. Us...

The best motivator priorities parents choose via analytical hierarchy process

Science.gov (United States)

Farah, R. N.; Latha, P.

2015-05-01

Motivation is probably the most important factor that educators can target in order to improve learning. Numerous cross-disciplinary theories have been postulated to explain motivation. While each of these theories has some truth, no single theory seems to adequately explain all human motivation. The fact is that human beings in general and pupils in particular are complex creatures with complex needs and desires. In this paper, Analytic Hierarchy Process (AHP) has been proposed as an emerging solution to move towards too large, dynamic and complex real world multi-criteria decision making problems in selecting the most suitable motivator when choosing school for their children. Data were analyzed using SPSS 17.0 ("Statistical Package for Social Science") software. Statistic testing used are descriptive and inferential statistic. Descriptive statistic used to identify respondent pupils and parents demographic factors. The statistical testing used to determine the pupils and parents highest motivator priorities and parents' best priorities using AHP to determine the criteria chosen by parents such as school principals, teachers, pupils and parents. The moderating factors are selected schools based on "Standard Kualiti Pendidikan Malaysia" (SKPM) in Ampang. Inferential statistics such as One-way ANOVA used to get the significant and data used to calculate the weightage of AHP. School principals is found to be the best motivator for parents in choosing school for their pupils followed by teachers, parents and pupils.

Four points function fitted and first derivative procedure for determining the end points in potentiometric titration curves: statistical analysis and method comparison.

Science.gov (United States)

Kholeif, S A

2001-06-01

A new method that belongs to the differential category for determining the end points from potentiometric titration curves is presented. It uses a preprocess to find first derivative values by fitting four data points in and around the region of inflection to a non-linear function, and then locate the end point, usually as a maximum or minimum, using an inverse parabolic interpolation procedure that has an analytical solution. The behavior and accuracy of the sigmoid and cumulative non-linear functions used are investigated against three factors. A statistical evaluation of the new method using linear least-squares method validation and multifactor data analysis are covered. The new method is generally applied to symmetrical and unsymmetrical potentiometric titration curves, and the end point is calculated using numerical procedures only. It outperforms the "parent" regular differential method in almost all factors levels and gives accurate results comparable to the true or estimated true end points. Calculated end points from selected experimental titration curves compatible with the equivalence point category of methods, such as Gran or Fortuin, are also compared with the new method.

Statistical Anxiety and Attitudes Towards Statistics: Development of a Comprehensive Danish Instrument

DEFF Research Database (Denmark)

Nielsen, Tine; Kreiner, Svend

Short abstract Motivated by experiencing with students’ psychological barriers for learning statistics we modified and extended the Statistical Anxiety Rating Scale (STARS) to develop a contemporary Danish measure of attitudes and relationship to statistics for use with higher education students...... with evidence of DIF in all cases: One TCA-item functioned differentially relative to age, one WS-item functioned differentially relative to statistics course (first or second), and two IA-items functioned differentially relative to statistics course and academic discipline (sociology, public health...

Teacher-student interpersonal relationships do change and affect academic motivation : A multilevel growth curve modelling

NARCIS (Netherlands)

Maulana, Ridwan; Opdenakker, Marie; Bosker, Roel

Background Research has shown that the teacher–student interpersonal relationship (TSIR) is important for student motivation. Although TSIR has received a growing interest, there are only few studies that focus on changes and links between TSIR and student academic motivation in a longitudinal

Growth Curve Analysis and Change-Points Detection in Extremes

KAUST Repository

Meng, Rui

2016-05-15

The thesis consists of two coherent projects. The first project presents the results of evaluating salinity tolerance in barley using growth curve analysis where different growth trajectories are observed within barley families. The study of salinity tolerance in plants is crucial to understanding plant growth and productivity. Because fully-automated smarthouses with conveyor systems allow non-destructive and high-throughput phenotyping of large number of plants, it is now possible to apply advanced statistical tools to analyze daily measurements and to study salinity tolerance. To compare different growth patterns of barley variates, we use functional data analysis techniques to analyze the daily projected shoot areas. In particular, we apply the curve registration method to align all the curves from the same barley family in order to summarize the family-wise features. We also illustrate how to use statistical modeling to account for spatial variation in microclimate in smarthouses and for temporal variation across runs, which is crucial for identifying traits of the barley variates. In our analysis, we show that the concentrations of sodium and potassium in leaves are negatively correlated, and their interactions are associated with the degree of salinity tolerance. The second project studies change-points detection methods in extremes when multiple time series data are available. Motived by the scientific question of whether the chances to experience extreme weather are different in different seasons of a year, we develop a change-points detection model to study changes in extremes or in the tail of a distribution. Most of existing models identify seasons from multiple yearly time series assuming a season or a change-point location remains exactly the same across years. In this work, we propose a random effect model that allows the change-point to vary from year to year, following a given distribution. Both parametric and nonparametric methods are developed

Modelling stochastic chances in curve shape, with an application to cancer diagnostics

DEFF Research Database (Denmark)

Hobolth, A; Jensen, Eva B. Vedel

2000-01-01

Often, the statistical analysis of the shape of a random planar curve is based on a model for a polygonal approximation to the curve. In the present paper, we instead describe the curve as a continuous stochastic deformation of a template curve. The advantage of this continuous approach is that t......Often, the statistical analysis of the shape of a random planar curve is based on a model for a polygonal approximation to the curve. In the present paper, we instead describe the curve as a continuous stochastic deformation of a template curve. The advantage of this continuous approach...... is that the parameters in the model do not relate to a particular polygonal approximation. A somewhat similar approach has been used by Kent et al. (1996), who describe the limiting behaviour of a model with a first-order Markov property as the landmarks on the curve become closely spaced; see also Grenander(1993...

Theoretical melting curve of caesium

International Nuclear Information System (INIS)

Simozar, S.; Girifalco, L.A.; Pennsylvania Univ., Philadelphia

1983-01-01

A statistical-mechanical model is developed to account for the complex melting curve of caesium. The model assumes the existence of three different species of caesium defined by three different electronic states. On the basis of this model, the free energy of melting and the melting curve are computed up to 60 kbar, using the solid-state data and the initial slope of the fusion curve as input parameters. The calculated phase diagram agrees with experiment to within the experimental error. Other thermodynamic properties including the entropy and volume of melting were also computed, and they agree with experiment. Since the theory requires only one adjustable constant, this is taken as strong evidence that the three-species model is satisfactory for caesium. (author)

Applied Problems and Use of Technology in an Aligned Way in Basic Courses in Probability and Statistics for Engineering Students--A Way to Enhance Understanding and Increase Motivation

Science.gov (United States)

Zetterqvist, Lena

2017-01-01

Researchers and teachers often recommend motivating exercises and use of mathematics or statistics software for the teaching of basic courses in probability and statistics. Our courses are given to large groups of engineering students at Lund Institute of Technology. We found that the mere existence of real-life data and technology in a course…

Achievement Motivation of Primary Mathematics Education Teacher Candidates According to Their Cognitive Styles and Motivation Styles

Science.gov (United States)

Yaman, Hakan; Dündar, Sefa; Ayvaz, Ülkü

2015-01-01

The aim of this study is to reveal whether there is relation between achievement motivations of teacher candidates according to their cognitive styles and motivation styles or not. This study was designed as a quantitative study due to collecting quantitative data and running statistical analyses. Both comparative and correlational survey methods…

Generalized t-statistic for two-group classification.

Science.gov (United States)

Komori, Osamu; Eguchi, Shinto; Copas, John B

2015-06-01

In the classic discriminant model of two multivariate normal distributions with equal variance matrices, the linear discriminant function is optimal both in terms of the log likelihood ratio and in terms of maximizing the standardized difference (the t-statistic) between the means of the two distributions. In a typical case-control study, normality may be sensible for the control sample but heterogeneity and uncertainty in diagnosis may suggest that a more flexible model is needed for the cases. We generalize the t-statistic approach by finding the linear function which maximizes a standardized difference but with data from one of the groups (the cases) filtered by a possibly nonlinear function U. We study conditions for consistency of the method and find the function U which is optimal in the sense of asymptotic efficiency. Optimality may also extend to other measures of discriminatory efficiency such as the area under the receiver operating characteristic curve. The optimal function U depends on a scalar probability density function which can be estimated non-parametrically using a standard numerical algorithm. A lasso-like version for variable selection is implemented by adding L1-regularization to the generalized t-statistic. Two microarray data sets in the study of asthma and various cancers are used as motivating examples. © 2014, The International Biometric Society.

Social motivation and health in college club swimming.

Science.gov (United States)

Anderson, Austin R; Ramos, William D

2018-03-22

Participation in recreational sport clubs on campus is a popular student activity nationwide. These sport-based organizations provide a host of benefits within recognized dimensions of health and wellness. Understanding participants' motives for engaging in these types of activities can provide insight in design and delivery and enhance participant health. This study focuses on outcomes related to the social motivations for participation in a recreational sport swim club and their potential relationship to social health. Current members of recreational swimming clubs were contacted for participation in the study from March-April 2016. A Leisure Motivation Scale (LMS) survey was sent electronically to 196 collegiate swim clubs nationwide. Aggregate and multivariate analyses from 1011 responses were conducted to examine the social motivation and motivational differences of participants. Social motivations emerged as the predominate motivational construct, indicating important implications for social health improvement through participation. Demographically, results indicated no statistically significant differences in social motivation factors based on participant gender, and statistically significant differences within participant race, university affiliation and practice frequency. Impacts of these findings are important for practitioners and participants when evaluating the potential these programs have to influence participant social health.

Digital Level Layers for Digital Curve Decomposition and Vectorization

Directory of Open Access Journals (Sweden)

Laurent Provot

2014-07-01

Full Text Available The purpose of this paper is to present Digital Level Layers and show the motivations for working with such analytical primitives in the framework of Digital Geometry. We first compare their properties to morphological and topological counterparts, and then we explain how to recognize them and use them to decompose or vectorize digital curves and contours.

Families of bitangent planes of space curves and minimal non-fibration families

KAUST Repository

Lubbes, Niels

2014-01-01

. Such families are called minimal non-fibration families. Families of bitangent planes of cone curves correspond to minimal non-fibration families. The main motivation of this paper is to classify minimal non-fibration families. We present algorithms which

Power of tests for comparing trend curves with application to national immunization survey (NIS).

Science.gov (United States)

Zhao, Zhen

2011-02-28

To develop statistical tests for comparing trend curves of study outcomes between two socio-demographic strata across consecutive time points, and compare statistical power of the proposed tests under different trend curves data, three statistical tests were proposed. For large sample size with independent normal assumption among strata and across consecutive time points, the Z and Chi-square test statistics were developed, which are functions of outcome estimates and the standard errors at each of the study time points for the two strata. For small sample size with independent normal assumption, the F-test statistic was generated, which is a function of sample size of the two strata and estimated parameters across study period. If two trend curves are approximately parallel, the power of Z-test is consistently higher than that of both Chi-square and F-test. If two trend curves cross at low interaction, the power of Z-test is higher than or equal to the power of both Chi-square and F-test; however, at high interaction, the powers of Chi-square and F-test are higher than that of Z-test. The measurement of interaction of two trend curves was defined. These tests were applied to the comparison of trend curves of vaccination coverage estimates of standard vaccine series with National Immunization Survey (NIS) 2000-2007 data. Copyright © 2011 John Wiley & Sons, Ltd.

SPIDERMAN: an open-source code to model phase curves and secondary eclipses

Science.gov (United States)

Louden, Tom; Kreidberg, Laura

2018-03-01

We present SPIDERMAN (Secondary eclipse and Phase curve Integrator for 2D tempERature MAppiNg), a fast code for calculating exoplanet phase curves and secondary eclipses with arbitrary surface brightness distributions in two dimensions. Using a geometrical algorithm, the code solves exactly the area of sections of the disc of the planet that are occulted by the star. The code is written in C with a user-friendly Python interface, and is optimised to run quickly, with no loss in numerical precision. Approximately 1000 models can be generated per second in typical use, making Markov Chain Monte Carlo analyses practicable. The modular nature of the code allows easy comparison of the effect of multiple different brightness distributions for the dataset. As a test case we apply the code to archival data on the phase curve of WASP-43b using a physically motivated analytical model for the two dimensional brightness map. The model provides a good fit to the data; however, it overpredicts the temperature of the nightside. We speculate that this could be due to the presence of clouds on the nightside of the planet, or additional reflected light from the dayside. When testing a simple cloud model we find that the best fitting model has a geometric albedo of 0.32 ± 0.02 and does not require a hot nightside. We also test for variation of the map parameters as a function of wavelength and find no statistically significant correlations. SPIDERMAN is available for download at https://github.com/tomlouden/spiderman.

SPIDERMAN: an open-source code to model phase curves and secondary eclipses

Science.gov (United States)

Louden, Tom; Kreidberg, Laura

2018-06-01

We present SPIDERMAN (Secondary eclipse and Phase curve Integrator for 2D tempERature MAppiNg), a fast code for calculating exoplanet phase curves and secondary eclipses with arbitrary surface brightness distributions in two dimensions. Using a geometrical algorithm, the code solves exactly the area of sections of the disc of the planet that are occulted by the star. The code is written in C with a user-friendly Python interface, and is optimized to run quickly, with no loss in numerical precision. Approximately 1000 models can be generated per second in typical use, making Markov Chain Monte Carlo analyses practicable. The modular nature of the code allows easy comparison of the effect of multiple different brightness distributions for the data set. As a test case, we apply the code to archival data on the phase curve of WASP-43b using a physically motivated analytical model for the two-dimensional brightness map. The model provides a good fit to the data; however, it overpredicts the temperature of the nightside. We speculate that this could be due to the presence of clouds on the nightside of the planet, or additional reflected light from the dayside. When testing a simple cloud model, we find that the best-fitting model has a geometric albedo of 0.32 ± 0.02 and does not require a hot nightside. We also test for variation of the map parameters as a function of wavelength and find no statistically significant correlations. SPIDERMAN is available for download at https://github.com/tomlouden/spiderman.

Wind Turbine Power Curves Incorporating Turbulence Intensity

DEFF Research Database (Denmark)

Sørensen, Emil Hedevang Lohse

2014-01-01

. The model and method are parsimonious in the sense that only a single function (the zero-turbulence power curve) and a single auxiliary parameter (the equivalent turbulence factor) are needed to predict the mean power at any desired turbulence intensity. The method requires only ten minute statistics......The performance of a wind turbine in terms of power production (the power curve) is important to the wind energy industry. The current IEC-61400-12-1 standard for power curve evaluation recognizes only the mean wind speed at hub height and the air density as relevant to the power production...

ITSA: Internet Traffic Statistics Archive

NARCIS (Netherlands)

Hoogesteger, Martijn; de Oliveira Schmidt, R.; Pras, Aiko

Motivated by the fact that comprehensive and long term Internet traffic measurements can be hard to obtain, we have proposed and developed the Internet Traffic Statistics Archive (ITSA). Since 2013, ITSA concentrates reports on high-level statistics of Internet traffic worldwide. Examples of

Hospital nurses' work motivation.

Science.gov (United States)

Toode, Kristi; Routasalo, Pirkko; Helminen, Mika; Suominen, Tarja

2015-06-01

The knowledge surrounding nurses' work motivation is currently insufficient, and previous studies have rarely taken into account the role of many influential background factors. This study investigates the motivation of Estonian nurses in hospitals, and how individual and organisational background factors influence their motivation to work. The study is quantitative and cross-sectional. An electronically self-reported questionnaire was used for data collection. The sample comprised of 201 Registered Nurses working in various hospital settings in Estonia. Data were analysed using descriptive statistics, two-sample Wilcoxon rank-sum (Mann-Whitney) test, Kruskal-Wallis equality-of-populations rank test and Spearman's correlation. Both extrinsic and intrinsic motivations were noted among hospital nurses. Nurses were moderately externally motivated (M = 3.63, SD = 0.89) and intrinsically strongly motivated (M = 4.98, SD = 1.03). A nurses' age and the duration of service were positively correlated with one particular area of extrinsic work motivation, namely introjected regulation (p extrinsic motivation (p = 0.016) and intrinsic work motivation (p = 0.004). The findings expand current knowledge of nurses' work motivation by describing the amount and orientation of work motivation among hospital nurses and highlighting background factors which should be taken into account in order to sustain and increase their intrinsic work motivation. The instrument used in the study can be an effective tool for nurse managers to determine a nurse's reasons to work and to choose a proper motivational strategy. Further research and testing of the instrument in different countries and in different contexts of nursing is however required. © 2014 Nordic College of Caring Science.

Generalized $L-, M-$, and $R$-Statistics

OpenAIRE

Serfling, Robert J.

1984-01-01

A class of statistics generalizing $U$-statistics and $L$-statistics, and containing other varieties of statistic as well, such as trimmed $U$-statistics, is studied. Using the differentiable statistical function approach, differential approximations are obtained and the influence curves of these generalized $L$-statistics are derived. These results are employed to establish asymptotic normality for such statistics. Parallel generalizations of $M$- and $R$-statistics are noted. Strong converg...

Measuring medical students' motivation to learning anatomy by cadaveric dissection.

Science.gov (United States)

Abdel Meguid, Eiman M; Khalil, Mohammed K

2017-07-01

Motivation and learning are inter-related. It is well known that motivating learners is clearly a complex endeavor, which can be influenced by the educational program and the learning environment. Limited research has been conducted to examine students' motivation as a method to assess the effectiveness of dissection in medical education. This study aimed to assess and analyze students' motivation following their dissection experience. A 29-item survey was developed based on the Attention, Relevance, Confidence, and Satisfaction model of motivation. Descriptive statistics were undertaken to describe students' motivation to the dissection experience. T-test and ANOVA were used to compare differences in motivational scores between gender and educational characteristics of students. Dissection activities appear to promote students' motivation. Gender difference was statistically significant as males were more motivated by the dissection experience than females. Comparison between students with different knowledge of anatomy was also significantly different. The study is an important step in the motivational design to improve students' motivation to learn. The outcome of this study provides guidance to the selection of specific strategies to increase motivation by generating motivational strategies/tactics to facilitate learning. Anat Sci Educ 10: 363-371. © 2016 American Association of Anatomists. © 2016 American Association of Anatomists.

Families of bitangent planes of space curves and minimal non-fibration families

KAUST Repository

Lubbes, Niels

2014-01-01

A cone curve is a reduced sextic space curve which lies on a quadric cone and does not pass through the vertex. We classify families of bitangent planes of cone curves. The methods we apply can be used for any space curve with ADE singularities, though in this paper we concentrate on cone curves. An embedded complex projective surface which is adjoint to a degree one weak Del Pezzo surface contains families of minimal degree rational curves, which cannot be defined by the fibers of a map. Such families are called minimal non-fibration families. Families of bitangent planes of cone curves correspond to minimal non-fibration families. The main motivation of this paper is to classify minimal non-fibration families. We present algorithms which compute all bitangent families of a given cone curve and their geometric genus. We consider cone curves to be equivalent if they have the same singularity configuration. For each equivalence class of cone curves we determine the possible number of bitangent families and the number of rational bitangent families. Finally we compute an example of a minimal non-fibration family on an embedded weak degree one Del Pezzo surface.

Object-Image Correspondence for Algebraic Curves under Projections

Directory of Open Access Journals (Sweden)

Joseph M. Burdis

2013-03-01

Full Text Available We present a novel algorithm for deciding whether a given planar curve is an image of a given spatial curve, obtained by a central or a parallel projection with unknown parameters. The motivation comes from the problem of establishing a correspondence between an object and an image, taken by a camera with unknown position and parameters. A straightforward approach to this problem consists of setting up a system of conditions on the projection parameters and then checking whether or not this system has a solution. The computational advantage of the algorithm presented here, in comparison to algorithms based on the straightforward approach, lies in a significant reduction of a number of real parameters that need to be eliminated in order to establish existence or non-existence of a projection that maps a given spatial curve to a given planar curve. Our algorithm is based on projection criteria that reduce the projection problem to a certain modification of the equivalence problem of planar curves under affine and projective transformations. To solve the latter problem we make an algebraic adaptation of signature construction that has been used to solve the equivalence problems for smooth curves. We introduce a notion of a classifying set of rational differential invariants and produce explicit formulas for such invariants for the actions of the projective and the affine groups on the plane.

Characterization of time series via Rényi complexity-entropy curves

Science.gov (United States)

Jauregui, M.; Zunino, L.; Lenzi, E. K.; Mendes, R. S.; Ribeiro, H. V.

2018-05-01

One of the most useful tools for distinguishing between chaotic and stochastic time series is the so-called complexity-entropy causality plane. This diagram involves two complexity measures: the Shannon entropy and the statistical complexity. Recently, this idea has been generalized by considering the Tsallis monoparametric generalization of the Shannon entropy, yielding complexity-entropy curves. These curves have proven to enhance the discrimination among different time series related to stochastic and chaotic processes of numerical and experimental nature. Here we further explore these complexity-entropy curves in the context of the Rényi entropy, which is another monoparametric generalization of the Shannon entropy. By combining the Rényi entropy with the proper generalization of the statistical complexity, we associate a parametric curve (the Rényi complexity-entropy curve) with a given time series. We explore this approach in a series of numerical and experimental applications, demonstrating the usefulness of this new technique for time series analysis. We show that the Rényi complexity-entropy curves enable the differentiation among time series of chaotic, stochastic, and periodic nature. In particular, time series of stochastic nature are associated with curves displaying positive curvature in a neighborhood of their initial points, whereas curves related to chaotic phenomena have a negative curvature; finally, periodic time series are represented by vertical straight lines.

Functional principal component analysis of glomerular filtration rate curves after kidney transplant.

Science.gov (United States)

Dong, Jianghu J; Wang, Liangliang; Gill, Jagbir; Cao, Jiguo

2017-01-01

This article is motivated by some longitudinal clinical data of kidney transplant recipients, where kidney function progression is recorded as the estimated glomerular filtration rates at multiple time points post kidney transplantation. We propose to use the functional principal component analysis method to explore the major source of variations of glomerular filtration rate curves. We find that the estimated functional principal component scores can be used to cluster glomerular filtration rate curves. Ordering functional principal component scores can detect abnormal glomerular filtration rate curves. Finally, functional principal component analysis can effectively estimate missing glomerular filtration rate values and predict future glomerular filtration rate values.

Incentivizing with Bonus in a College Statistics Course

Science.gov (United States)

Ingalls, Victoria

2018-01-01

Many studies have argued the negative effects of external rewards on internal motivation while others assert that external motivation does not necessarily undermine intrinsic motivation. At a private university, students were given the option to earn bonus points for achieving mastery in the online homework systems associated with Statistics and…

Motivational Strategies and Possible Influence on Secondary School ...

African Journals Online (AJOL)

... and administered to the 360 teachers. The data collected were subjected to statistical analyses using ANOVA. The test yielded significant influence of motivational strategies on teachers' work performance. Based on the findings, recommendations were made. KEY WORDS: Motivational Strategies, Teaching Performance.

Drinking motives and links to alcohol use in 13 European countries

DEFF Research Database (Denmark)

Kuntsche, Emmanuel; Gabhainn, Saoirse Nic; Roberts, Chris

2014-01-01

ABSTRACT. Objective: The purpose of this study was to test the structure and endorsement of drinking motives and their links to alcohol use among 11- to 19-year-olds from 13 European countries. Method: Confirmatory factor analysis, latent growth curves, and multiple regression models were conducted......, based on a sample of 33,813 alcohol-using students from Belgium, Denmark, Estonia, Finland, Hungary, Ireland, Italy, Poland, Portugal, Scotland, Slovakia, Switzerland, and Wales who completed the Drinking Motives Questionnaire Revised Short Form (DMQ-R SF). Results: The findings confirmed...... European countries. The results confirmed that, across countries, social motives were strongly positively related to drinking frequency, enhancement motives were strongly positively related to frequency of drunkenness, and conformity motives were negatively related to both alcohol outcomes. Against our...

Marginal versus joint Box-Cox transformation with applications to percentile curve construction for IgG subclasses and blood pressures.

Science.gov (United States)

He, Xuming; Ng, K W; Shi, Jian

2003-02-15

When age-specific percentile curves are constructed for several correlated variables, the marginal method of handling one variable at a time has typically been used. We address the question, frequently asked by practitioners, of whether we can achieve efficiency gains by joint estimation. We focus on a simple but common method of Box-Cox transformation and assess the statistical impact of a joint transformation to multivariate normality on the percentile curve estimation for correlated variables. We find that there is little gain from the joint transformation for estimating percentiles around the median but a noticeable reduction in variances is possible for estimating extreme percentiles that are usually of main interest in medical and biological applications. Our study is motivated by problems in constructing percentile charts for IgG subclasses of children and for blood pressures in adult populations, both of which are discussed in the paper as examples, and yet our general findings are applicable to a wide range of other problems. Copyright 2003 John Wiley & Sons, Ltd.

Implementation of the Master Curve method in ProSACC

Energy Technology Data Exchange (ETDEWEB)

Feilitzen, Carl von; Sattari-Far, Iradj [Inspecta Technology AB, Stockholm (Sweden)

2012-03-15

Cleavage fracture toughness data display normally large amount of statistical scatter in the transition region. The cleavage toughness data in this region is specimen size-dependent, and should be treated statistically rather than deterministically. Master Curve methodology is a procedure for mechanical testing and statistical analysis of fracture toughness of ferritic steels in the transition region. The methodology accounts for temperature and size dependence of fracture toughness. Using the Master Curve methodology for evaluation of the fracture toughness in the transition region releases the overconservatism that has been observed in using the ASME-KIC curve. One main advantage of using the Master Curve methodology is possibility to use small Charpy-size specimens to determine fracture toughness. Detailed description of the Master Curve methodology is given by Sattari-Far and Wallin [2005). ProSACC is a suitable program in using for structural integrity assessments of components containing crack like defects and for defect tolerance analysis. The program gives possibilities to conduct assessments based on deterministic or probabilistic grounds. The method utilized in ProSACC is based on the R6-method developed at Nuclear Electric plc, Milne et al [1988]. The basic assumption in this method is that fracture in a cracked body can be described by two parameters Kr and Lr. The parameter Kr is the ratio between the stress intensity factor and the fracture toughness of the material. The parameter Lr is the ratio between applied load and the plastic limit load of the structure. The ProSACC assessment results are therefore highly dependent on the applied fracture toughness value in the assessment. In this work, the main options of the Master Curve methodology are implemented in the ProSACC program. Different options in evaluating Master Curve fracture toughness from standard fracture toughness testing data or impact testing data are considered. In addition, the

Implementation of the Master Curve method in ProSACC

International Nuclear Information System (INIS)

Feilitzen, Carl von; Sattari-Far, Iradj

2012-03-01

Cleavage fracture toughness data display normally large amount of statistical scatter in the transition region. The cleavage toughness data in this region is specimen size-dependent, and should be treated statistically rather than deterministically. Master Curve methodology is a procedure for mechanical testing and statistical analysis of fracture toughness of ferritic steels in the transition region. The methodology accounts for temperature and size dependence of fracture toughness. Using the Master Curve methodology for evaluation of the fracture toughness in the transition region releases the overconservatism that has been observed in using the ASME-KIC curve. One main advantage of using the Master Curve methodology is possibility to use small Charpy-size specimens to determine fracture toughness. Detailed description of the Master Curve methodology is given by Sattari-Far and Wallin [2005). ProSACC is a suitable program in using for structural integrity assessments of components containing crack like defects and for defect tolerance analysis. The program gives possibilities to conduct assessments based on deterministic or probabilistic grounds. The method utilized in ProSACC is based on the R6-method developed at Nuclear Electric plc, Milne et al [1988]. The basic assumption in this method is that fracture in a cracked body can be described by two parameters Kr and Lr. The parameter Kr is the ratio between the stress intensity factor and the fracture toughness of the material. The parameter Lr is the ratio between applied load and the plastic limit load of the structure. The ProSACC assessment results are therefore highly dependent on the applied fracture toughness value in the assessment. In this work, the main options of the Master Curve methodology are implemented in the ProSACC program. Different options in evaluating Master Curve fracture toughness from standard fracture toughness testing data or impact testing data are considered. In addition, the

Cannabis, motivation, and life satisfaction in an internet sample

Directory of Open Access Journals (Sweden)

Wilcox Rand

2006-01-01

Full Text Available Abstract Although little evidence supports cannabis-induced amotivational syndrome, sources continue to assert that the drug saps motivation 1, which may guide current prohibitions. Few studies report low motivation in chronic users; another reveals that they have higher subjective wellbeing. To assess differences in motivation and subjective wellbeing, we used a large sample (N = 487 and strict definitions of cannabis use (7 days/week and abstinence (never. Standard statistical techniques showed no differences. Robust statistical methods controlling for heteroscedasticity, non-normality and extreme values found no differences in motivation but a small difference in subjective wellbeing. Medical users of cannabis reporting health problems tended to account for a significant portion of subjective wellbeing differences, suggesting that illness decreased wellbeing. All p-values were above p = .05. Thus, daily use of cannabis does not impair motivation. Its impact on subjective wellbeing is small and may actually reflect lower wellbeing due to medical symptoms rather than actual consumption of the plant.

Differential geometry curves, surfaces, manifolds

CERN Document Server

Kohnel, Wolfgang

2002-01-01

This carefully written book is an introduction to the beautiful ideas and results of differential geometry. The first half covers the geometry of curves and surfaces, which provide much of the motivation and intuition for the general theory. Special topics that are explored include Frenet frames, ruled surfaces, minimal surfaces and the Gauss-Bonnet theorem. The second part is an introduction to the geometry of general manifolds, with particular emphasis on connections and curvature. The final two chapters are insightful examinations of the special cases of spaces of constant curvature and Einstein manifolds. The text is illustrated with many figures and examples. The prerequisites are undergraduate analysis and linear algebra.

Reproducing tailing in breakthrough curves: Are statistical models equally representative and predictive?

Science.gov (United States)

Pedretti, Daniele; Bianchi, Marco

2018-03-01

Breakthrough curves (BTCs) observed during tracer tests in highly heterogeneous aquifers display strong tailing. Power laws are popular models for both the empirical fitting of these curves, and the prediction of transport using upscaling models based on best-fitted estimated parameters (e.g. the power law slope or exponent). The predictive capacity of power law based upscaling models can be however questioned due to the difficulties to link model parameters with the aquifers' physical properties. This work analyzes two aspects that can limit the use of power laws as effective predictive tools: (a) the implication of statistical subsampling, which often renders power laws undistinguishable from other heavily tailed distributions, such as the logarithmic (LOG); (b) the difficulties to reconcile fitting parameters obtained from models with different formulations, such as the presence of a late-time cutoff in the power law model. Two rigorous and systematic stochastic analyses, one based on benchmark distributions and the other on BTCs obtained from transport simulations, are considered. It is found that a power law model without cutoff (PL) results in best-fitted exponents (αPL) falling in the range of typical experimental values reported in the literature (1.5 tailing becomes heavier. Strong fluctuations occur when the number of samples is limited, due to the effects of subsampling. On the other hand, when the power law model embeds a cutoff (PLCO), the best-fitted exponent (αCO) is insensitive to the degree of tailing and to the effects of subsampling and tends to a constant αCO ≈ 1. In the PLCO model, the cutoff rate (λ) is the parameter that fully reproduces the persistence of the tailing and is shown to be inversely correlated to the LOG scale parameter (i.e. with the skewness of the distribution). The theoretical results are consistent with the fitting analysis of a tracer test performed during the MADE-5 experiment. It is shown that a simple

Application of Master Curve Methodology for Structural Integrity Assessments of Nuclear Components

Energy Technology Data Exchange (ETDEWEB)

Sattari-Far, Iradj [Det Norske Veritas, Stockholm (Sweden); Wallin, Kim [VTT, Esbo (Finland)

2005-10-15

The objective was to perform an in-depth investigation of the Master Curve methodology and also based on this method develop a procedure for fracture assessments of nuclear components. The project has sufficiently illustrated the capabilities of the Master Curve methodology for fracture assessments of nuclear components. Within the scope of this work, the theoretical background of the methodology and its validation on small and large specimens has been studied and presented to a sufficiently large extent, as well as the correlations between the charpy-V data and the Master Curve T{sub 0} reference temperature in the evaluation of fracture toughness. The work gives a comprehensive report of the background theory and the different applications of the Master Curve methodology. The main results of the work have shown that the cleavage fracture toughness is characterized by a large amount of statistical scatter in the transition region, it is specimen size dependent and it should be treated statistically rather than deterministically. The Master Curve methodology is able to make use of statistical data in a consistent way. Furthermore, the Master Curve methodology provides a more precise prediction of the fracture toughness of embrittled materials in comparison with the ASME K{sub IC} reference curve, which often gives over-conservative results. The suggested procedure in this study, concerning the application of the Master Curve method in fracture assessments of ferritic steels in the transition region and the low shelf regions, is valid for the temperatures range T{sub 0}-50{<=}T{<=}T{sub 0}+50 deg C. If only approximate information is required, the Master Curve may well be extrapolated outside this temperature range. The suggested procedure has also been illustrated for some examples.

Comparison of power curve monitoring methods

Directory of Open Access Journals (Sweden)

Cambron Philippe

2017-01-01

Full Text Available Performance monitoring is an important aspect of operating wind farms. This can be done through the power curve monitoring (PCM of wind turbines (WT. In the past years, important work has been conducted on PCM. Various methodologies have been proposed, each one with interesting results. However, it is difficult to compare these methods because they have been developed using their respective data sets. The objective of this actual work is to compare some of the proposed PCM methods using common data sets. The metric used to compare the PCM methods is the time needed to detect a change in the power curve. Two power curve models will be covered to establish the effect the model type has on the monitoring outcomes. Each model was tested with two control charts. Other methodologies and metrics proposed in the literature for power curve monitoring such as areas under the power curve and the use of statistical copulas have also been covered. Results demonstrate that model-based PCM methods are more reliable at the detecting a performance change than other methodologies and that the effectiveness of the control chart depends on the types of shift observed.

Principal Curves on Riemannian Manifolds.

Science.gov (United States)

Hauberg, Soren

2016-09-01

Euclidean statistics are often generalized to Riemannian manifolds by replacing straight-line interpolations with geodesic ones. While these Riemannian models are familiar-looking, they are restricted by the inflexibility of geodesics, and they rely on constructions which are optimal only in Euclidean domains. We consider extensions of Principal Component Analysis (PCA) to Riemannian manifolds. Classic Riemannian approaches seek a geodesic curve passing through the mean that optimizes a criteria of interest. The requirements that the solution both is geodesic and must pass through the mean tend to imply that the methods only work well when the manifold is mostly flat within the support of the generating distribution. We argue that instead of generalizing linear Euclidean models, it is more fruitful to generalize non-linear Euclidean models. Specifically, we extend the classic Principal Curves from Hastie & Stuetzle to data residing on a complete Riemannian manifold. We show that for elliptical distributions in the tangent of spaces of constant curvature, the standard principal geodesic is a principal curve. The proposed model is simple to compute and avoids many of the pitfalls of traditional geodesic approaches. We empirically demonstrate the effectiveness of the Riemannian principal curves on several manifolds and datasets.

In Search for Anchors The Fundamental Motivational Force in Compensating for Human Vulnerability

Directory of Open Access Journals (Sweden)

Bagus Riyono

2012-09-01

Full Text Available The purpose of this study is to develop a new integrative theory of motivation drawn from the existing theories and data. The method used is a combination of meta-ethnography and grounded theory. The second phase of the study employed a thought experiment to test the newly developed theoretical propositions of motivational force. The first phase of the study revealed a central phenomenon for the occurrence of motivational force, i.e. “In Search for Anchors,” which is a result of the paradox between freedom to choose and human vulnerability. “Freedom to choose” is the central factor of a motivational model that includes “urge,” “challenge,” “incentive,” and “meaning.” These five factors are motivational sources, which have holistic-dynamic-integrative interaction. Human vulnerability is the other side of the motivational model that comprises risk, uncertainty, and hope that ignite motivational force. The dynamic interaction of risk, uncertainty, and hope is represented in a mathematical formula that produces the strength of the force, (R – H2 x U, which can be potrayed in a “twin-peak” curve. The thought experiment was conducted to test the hypothetical formula. The result shows that the “twin-peak” hypothesis is supported but the shape of the curve is found to be not symmetrical. The data show that hope is the strongest motivational force, therefore the formula is modified into = (R – U2 x H. The implication of the study and the utility of the new theory are discussed.

Modeling of a Robust Confidence Band for the Power Curve of a Wind Turbine.

Science.gov (United States)

Hernandez, Wilmar; Méndez, Alfredo; Maldonado-Correa, Jorge L; Balleteros, Francisco

2016-12-07

Having an accurate model of the power curve of a wind turbine allows us to better monitor its operation and planning of storage capacity. Since wind speed and direction is of a highly stochastic nature, the forecasting of the power generated by the wind turbine is of the same nature as well. In this paper, a method for obtaining a robust confidence band containing the power curve of a wind turbine under test conditions is presented. Here, the confidence band is bound by two curves which are estimated using parametric statistical inference techniques. However, the observations that are used for carrying out the statistical analysis are obtained by using the binning method, and in each bin, the outliers are eliminated by using a censorship process based on robust statistical techniques. Then, the observations that are not outliers are divided into observation sets. Finally, both the power curve of the wind turbine and the two curves that define the robust confidence band are estimated using each of the previously mentioned observation sets.

pROC: an open-source package for R and S+ to analyze and compare ROC curves.

Science.gov (United States)

Robin, Xavier; Turck, Natacha; Hainard, Alexandre; Tiberti, Natalia; Lisacek, Frédérique; Sanchez, Jean-Charles; Müller, Markus

2011-03-17

Receiver operating characteristic (ROC) curves are useful tools to evaluate classifiers in biomedical and bioinformatics applications. However, conclusions are often reached through inconsistent use or insufficient statistical analysis. To support researchers in their ROC curves analysis we developed pROC, a package for R and S+ that contains a set of tools displaying, analyzing, smoothing and comparing ROC curves in a user-friendly, object-oriented and flexible interface. With data previously imported into the R or S+ environment, the pROC package builds ROC curves and includes functions for computing confidence intervals, statistical tests for comparing total or partial area under the curve or the operating points of different classifiers, and methods for smoothing ROC curves. Intermediary and final results are visualised in user-friendly interfaces. A case study based on published clinical and biomarker data shows how to perform a typical ROC analysis with pROC. pROC is a package for R and S+ specifically dedicated to ROC analysis. It proposes multiple statistical tests to compare ROC curves, and in particular partial areas under the curve, allowing proper ROC interpretation. pROC is available in two versions: in the R programming language or with a graphical user interface in the S+ statistical software. It is accessible at http://expasy.org/tools/pROC/ under the GNU General Public License. It is also distributed through the CRAN and CSAN public repositories, facilitating its installation.

The Relationship Between Internal Motivation And Customer Satisfaction Of Posthaste Purchase

Directory of Open Access Journals (Sweden)

Farbodsouri

2017-06-01

Full Text Available The purpose of this study is performing an empirical study in the field of marketing in order to examine the relationship between internal motivation and customer satisfaction of posthaste purchase in stores that researcher made model have been used.In this model the relationship between internal motivation and customer satisfaction of posthaste purchase was investigated. To review research sample of 385 customers was selected as a stepwise clustering. Data gathered by standard questionnaire with 21 questions that its validity and reliability was confirmed and distributed among the statistical population. Data analysis was performed using descriptive statistics and inferential statistics. At the level of Descriptive statistics indices such as frequency and frequency percentage were used and in inferential statistics correlation methods structural equation modeling path analysis has been done using the spss and lisrel software. The results of the analysis showing the existence of a significant and positive impact of internal motivation on customer satisfaction of posthaste buying. In general the ability of the Tehran Hyperstar chain store to increase customers satisfaction of posthaste buying must pay special attention to the effective internal motivation of customers the impulsivity the pleasure of shopping fashion involvement personal identity p050.

Predicting Condom Use Using the Information-Motivation-Behavioral Skills (IMB) Model: A Multivariate Latent Growth Curve Analysis

Science.gov (United States)

Senn, Theresa E.; Scott-Sheldon, Lori A. J.; Vanable, Peter A.; Carey, Michael P.

2011-01-01

Background The Information-Motivation-Behavioral Skills (IMB) model often guides sexual risk reduction programs even though no studies have examined covariation in the theory’s constructs in a dynamic fashion with longitudinal data. Purpose Using new developments in latent growth modeling, we explore how changes in information, motivation, and behavioral skills over 9 months relate to changes in condom use among STD clinic patients. Methods Participants (N = 1281, 50% female, 66% African American) completed measures of IMB constructs at three time points. We used parallel process latent growth modeling to examine associations among intercepts and slopes of IMB constructs. Results Initial levels of motivation, behavioral skills, and condom use were all positively associated, with behavioral skills partially mediating associations between motivation and condom use. Changes over time in behavioral skills positively related to changes in condom use. Conclusions Results support the key role of behavioral skills in sexual risk reduction, suggesting these skills should be targeted in HIV prevention interventions. PMID:21638196

Deep-learnt classification of light curves

DEFF Research Database (Denmark)

Mahabal, Ashish; Gieseke, Fabian; Pai, Akshay Sadananda Uppinakudru

2017-01-01

is to derive statistical features from the time series and to use machine learning methods, generally supervised, to separate objects into a few of the standard classes. In this work, we transform the time series to two-dimensional light curve representations in order to classify them using modern deep......Astronomy light curves are sparse, gappy, and heteroscedastic. As a result standard time series methods regularly used for financial and similar datasets are of little help and astronomers are usually left to their own instruments and techniques to classify light curves. A common approach...... learning techniques. In particular, we show that convolutional neural networks based classifiers work well for broad characterization and classification. We use labeled datasets of periodic variables from CRTS survey and show how this opens doors for a quick classification of diverse classes with several...

The Use of Statistically Based Rolling Supply Curves for Electricity Market Analysis: A Preliminary Look

Energy Technology Data Exchange (ETDEWEB)

Jenkin, Thomas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Larson, Andrew [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ruth, Mark F [National Renewable Energy Laboratory (NREL), Golden, CO (United States); King, Ben [U.S. Department of Energy; Spitsen, Paul [U.S. Department of Energy

2018-03-27

In light of the changing electricity resource mixes across the United States, an important question in electricity modeling is how additions and retirements of generation, including additions in variable renewable energy (VRE) generation could impact markets by changing hourly wholesale energy prices. Instead of using resource-intensive production cost models (PCMs) or building and using simple generator supply curves, this analysis uses a 'top-down' approach based on regression analysis of hourly historical energy and load data to estimate the impact of supply changes on wholesale electricity prices, provided the changes are not so substantial that they fundamentally alter the market and dispatch-order driven behavior of non-retiring units. The rolling supply curve (RSC) method used in this report estimates the shape of the supply curve that fits historical hourly price and load data for given time intervals, such as two-weeks, and then repeats this on a rolling basis through the year. These supply curves can then be modified on an hourly basis to reflect the impact of generation retirements or additions, including VRE and then reapplied to the same load data to estimate the change in hourly electricity price. The choice of duration over which these RSCs are estimated has a significant impact on goodness of fit. For example, in PJM in 2015, moving from fitting one curve per year to 26 rolling two-week supply curves improves the standard error of the regression from 16 dollars/MWh to 6 dollars/MWh and the R-squared of the estimate from 0.48 to 0.76. We illustrate the potential use and value of the RSC method by estimating wholesale price effects under various generator retirement and addition scenarios, and we discuss potential limits of the technique, some of which are inherent. The ability to do this type of analysis is important to a wide range of market participants and other stakeholders, and it may have a role in complementing use of or providing

The learning curve for hip arthroscopy: a systematic review.

Science.gov (United States)

Hoppe, Daniel J; de Sa, Darren; Simunovic, Nicole; Bhandari, Mohit; Safran, Marc R; Larson, Christopher M; Ayeni, Olufemi R

2014-03-01

The learning curve for hip arthroscopy is consistently characterized as "steep." The purpose of this systematic review was to (1) identify the various learning curves reported in the literature, (2) examine the evidence supporting these curves, and (3) determine whether this evidence supports an accepted number of cases needed to achieve proficiency. The electronic databases Embase and Medline were screened for any clinical studies reporting learning curves in hip arthroscopy. Two reviewers conducted a full-text review of eligible studies and a hand search of conference proceedings and reference sections of the included articles. Inclusion/exclusion criteria were applied, and a quality assessment was completed for each included article. Descriptive statistics were compiled. We identified 6 studies with a total of 1,063 patients. Studies grouped surgical cases into "early" versus "late" in a surgeon's experience, with 30 cases being the most common cutoff used. Most of these studies used descriptive statistics and operative time and complication rates as measures of competence. Five of 6 studies showed improvement in these measures between early and late experience, but only one study proposed a bona fide curve. This review shows that when 30 cases was used as the cutoff point to differentiate between early and late cases in a surgeon's experience, there were significant reductions in operative time and complication rates. However, there was insufficient evidence to quantify the learning curve and validate 30, or any number of cases, as the point at which the learning curve plateaus. As a result, this number should be interpreted with caution. Level IV, systematic review of Level IV studies. Copyright © 2014 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Academic Motivations of Pre-Service English Language Teachers

Science.gov (United States)

Ariogul, Sibel

2009-01-01

This study examines the academic motivation, in a Turkish context, of Turkish pre-service English teachers to contribute field research. Students (n=287) completed the Academic Motivation Scale (AMS) and a demographic questionnaire. Data were analyzed using descriptive statistics, a one-way ANOVA, independent sample t-test, and Pearson product…

All of statistics a concise course in statistical inference

CERN Document Server

Wasserman, Larry

2004-01-01

This book is for people who want to learn probability and statistics quickly It brings together many of the main ideas in modern statistics in one place The book is suitable for students and researchers in statistics, computer science, data mining and machine learning This book covers a much wider range of topics than a typical introductory text on mathematical statistics It includes modern topics like nonparametric curve estimation, bootstrapping and classification, topics that are usually relegated to follow-up courses The reader is assumed to know calculus and a little linear algebra No previous knowledge of probability and statistics is required The text can be used at the advanced undergraduate and graduate level Larry Wasserman is Professor of Statistics at Carnegie Mellon University He is also a member of the Center for Automated Learning and Discovery in the School of Computer Science His research areas include nonparametric inference, asymptotic theory, causality, and applications to astrophysics, bi...

Localization of nonlinear excitations in curved waveguides

DEFF Research Database (Denmark)

Gaididei, Yu. B.; Christiansen, Peter Leth; Kevrekidis, P. G.

2005-01-01

numerical simulations of the nonlinear problem and in this case localized excitations are found to persist. We found also interesting relaxational dynamics. Analogies of the present problem in context related to atomic physics and particularly to Bose–Einstein condensation are discussed.......Motivated by the examples of a curved waveguide embedded in a photonic crystal and cold atoms moving in a waveguide created by a spatially inhomogeneous electromagnetic field, we examine the effects of geometry in a 'quantum channel' of parabolic form. Starting with the linear case we derive exact...

Markov model plus k-word distributions: a synergy that produces novel statistical measures for sequence comparison.

Science.gov (United States)

Dai, Qi; Yang, Yanchun; Wang, Tianming

2008-10-15

Many proposed statistical measures can efficiently compare biological sequences to further infer their structures, functions and evolutionary information. They are related in spirit because all the ideas for sequence comparison try to use the information on the k-word distributions, Markov model or both. Motivated by adding k-word distributions to Markov model directly, we investigated two novel statistical measures for sequence comparison, called wre.k.r and S2.k.r. The proposed measures were tested by similarity search, evaluation on functionally related regulatory sequences and phylogenetic analysis. This offers the systematic and quantitative experimental assessment of our measures. Moreover, we compared our achievements with these based on alignment or alignment-free. We grouped our experiments into two sets. The first one, performed via ROC (receiver operating curve) analysis, aims at assessing the intrinsic ability of our statistical measures to search for similar sequences from a database and discriminate functionally related regulatory sequences from unrelated sequences. The second one aims at assessing how well our statistical measure is used for phylogenetic analysis. The experimental assessment demonstrates that our similarity measures intending to incorporate k-word distributions into Markov model are more efficient.

Strong laws for generalized absolute Lorenz curves when data are stationary and ergodic sequences

NARCIS (Netherlands)

R. Helmers (Roelof); R. Zitikis

2004-01-01

textabstractWe consider generalized absolute Lorenz curves that include, as special cases, classical and generalized L - statistics as well as absolute or, in other words, generalized Lorenz curves. The curves are based on strictly stationary and ergodic sequences of random variables. Most of the

Using statistical correlation to compare geomagnetic data sets

Science.gov (United States)

Stanton, T.

2009-04-01

The major features of data curves are often matched, to a first order, by bump and wiggle matching to arrive at an offset between data sets. This poster describes a simple statistical correlation program that has proved useful during this stage by determining the optimal correlation between geomagnetic curves using a variety of fixed and floating windows. Its utility is suggested by the fact that it is simple to run, yet generates meaningful data comparisons, often when data noise precludes the obvious matching of curve features. Data sets can be scaled, smoothed, normalised and standardised, before all possible correlations are carried out between selected overlapping portions of each curve. Best-fit offset curves can then be displayed graphically. The program was used to cross-correlate directional and palaeointensity data from Holocene lake sediments (Stanton et al., submitted) and Holocene lava flows. Some example curve matches are shown, including some that illustrate the potential of this technique when examining particularly sparse data sets. Stanton, T., Snowball, I., Zillén, L. and Wastegård, S., submitted. Detecting potential errors in varve chronology and 14C ages using palaeosecular variation curves, lead pollution history and statistical correlation. Quaternary Geochronology.

Understanding gendered aspects of migration aspiration and motives of university students by multivariate statistical methods

Directory of Open Access Journals (Sweden)

Đula Borozan

2014-03-01

Full Text Available The paper deals with the application of multivariate analysis of variance and logistic regression in measuring, explaining and evaluating (i gender differences in expressing migration aspirations, and (ii a gender effect on migration motivation of university students in Croatia. The results supported the thesis that migration is a complex gendering process that assumes subjective assessment of the whole set of interrelated motives. According to logistic regression, gender is a significant predictor of migration aspirations among the selected demographic and socio-economic variables. A multivariate analysis of variance showed that gender and migration aspirations in interaction matter when it comes to migration motives, particularly related to the perceived importance of social networks. Females, and especially those who aspire to migrate, assessed these motives as more important than males.

A Bargaining Experiment To Motivate a Discussion on Fairness.

Science.gov (United States)

Dickinson, David L.

2002-01-01

Employs a classroom version of the research game, the Ultimatum Game, to teach undergraduate students how fairness affects behavior. Focuses on three concepts related to fairness. Finds that classroom results motivate discussion about a downward sloping demand curve for fairness. Provides an appendix that includes instructional materials. (JEH)

TYPE Ia SUPERNOVA LIGHT-CURVE INFERENCE: HIERARCHICAL BAYESIAN ANALYSIS IN THE NEAR-INFRARED

International Nuclear Information System (INIS)

Mandel, Kaisey S.; Friedman, Andrew S.; Kirshner, Robert P.; Wood-Vasey, W. Michael

2009-01-01

We present a comprehensive statistical analysis of the properties of Type Ia supernova (SN Ia) light curves in the near-infrared using recent data from Peters Automated InfraRed Imaging TELescope and the literature. We construct a hierarchical Bayesian framework, incorporating several uncertainties including photometric error, peculiar velocities, dust extinction, and intrinsic variations, for principled and coherent statistical inference. SN Ia light-curve inferences are drawn from the global posterior probability of parameters describing both individual supernovae and the population conditioned on the entire SN Ia NIR data set. The logical structure of the hierarchical model is represented by a directed acyclic graph. Fully Bayesian analysis of the model and data is enabled by an efficient Markov Chain Monte Carlo algorithm exploiting the conditional probabilistic structure using Gibbs sampling. We apply this framework to the JHK s SN Ia light-curve data. A new light-curve model captures the observed J-band light-curve shape variations. The marginal intrinsic variances in peak absolute magnitudes are σ(M J ) = 0.17 ± 0.03, σ(M H ) = 0.11 ± 0.03, and σ(M Ks ) = 0.19 ± 0.04. We describe the first quantitative evidence for correlations between the NIR absolute magnitudes and J-band light-curve shapes, and demonstrate their utility for distance estimation. The average residual in the Hubble diagram for the training set SNe at cz > 2000kms -1 is 0.10 mag. The new application of bootstrap cross-validation to SN Ia light-curve inference tests the sensitivity of the statistical model fit to the finite sample and estimates the prediction error at 0.15 mag. These results demonstrate that SN Ia NIR light curves are as effective as corrected optical light curves, and, because they are less vulnerable to dust absorption, they have great potential as precise and accurate cosmological distance indicators.

Motivational profile quality players handball

Directory of Open Access Journals (Sweden)

Alfonso Martínez Moreno

2017-06-01

Full Text Available In the sport context, elite category, it is necessary to know all the factors, which in one way or another, affect the athletes throughout the different competitions. The object of study is to know the motivational profile of elite handball players. The sample consisted of 495 players, of whom 47.8% were boys and 52.2% girls, their ages ranged from 12 to 16 years, with an average of 13.8 years (dt = 1.0. Descriptive statistical analyzes of the sample, absolute and relative frequencies were performed for the qualitative variables and for the quantitative values minimum, maximum, mean, standard deviation, Cronbach's alpha. Correlation between variables, with the Pearson correlation coefficient. The MANCOVA test was performed to determine if there were differences between the dimensions of the questionnaire, according to age and years of practice. The results reveal that handball players elite category of the sample object of study have mainly intrinsic motivation, achieving high scores on general motivation, motivation achievement and motivation stimulation. In addition to moderately high values in introjected regulation and very low values in demotivation.

On Motivation and Motivation

OpenAIRE

Mircea UDRESCU

2014-01-01

Economic motivations were a big influence on consumer behavior motivation. In this context, it is considered that the general motives which give motivation to purchase content can be structured into rational and emotional motives, the motives innate and acquired motives, all gaining an individual or group event. The study of consumer behavior, with general motivations, attention increasingly larger granted special incentives, consisting of assertiveness feeling (emerging desire for a product)...

Sketching Curves for Normal Distributions--Geometric Connections

Science.gov (United States)

Bosse, Michael J.

2006-01-01

Within statistics instruction, students are often requested to sketch the curve representing a normal distribution with a given mean and standard deviation. Unfortunately, these sketches are often notoriously imprecise. Poor sketches are usually the result of missing mathematical knowledge. This paper considers relationships which exist among…

Dynamics of embedded curves by doubly-nonlocal reaction-diffusion systems

Science.gov (United States)

von Brecht, James H.; Blair, Ryan

2017-11-01

We study a class of nonlocal, energy-driven dynamical models that govern the motion of closed, embedded curves from both an energetic and dynamical perspective. Our energetic results provide a variety of ways to understand physically motivated energetic models in terms of more classical, combinatorial measures of complexity for embedded curves. This line of investigation culminates in a family of complexity bounds that relate a rather broad class of models to a generalized, or weighted, variant of the crossing number. Our dynamic results include global well-posedness of the associated partial differential equations, regularity of equilibria for these flows as well as a more detailed investigation of dynamics near such equilibria. Finally, we explore a few global dynamical properties of these models numerically.

Statistical factors affecting the success of nuclear operations

International Nuclear Information System (INIS)

Sunder, S.; Stephenson, J.R.; Hochman, D.

1999-01-01

In this article, the authors present a statistical analysis to determine the operational, financial, technical, and managerial factors that most significantly affect the success of nuclear operations. The study analyzes data for over 70 nuclear plants and 40 operating companies over a period of five years in order to draw conclusions that they hope will be of interest to utility companies and public utility commissions as they seek ways to improve rates of success in nuclear operations. Some of these conclusions will not be surprising--for example, that older plants have heavier maintenance requirements--but others are less intuitive. For instance, the observation that operators of fewer plants have lower costs suggests that any experience curve benefits associated with managing multiple nuclear facilities is overshadowed by the logistic problems of multiple facilities. After presenting a brief history of nuclear power in America, the authors outline the motivations of the study and the methodology of their analysis. They end the article with the results of the study and discuss some of the managerial implications of these findings

p-Curve and p-Hacking in Observational Research.

Science.gov (United States)

Bruns, Stephan B; Ioannidis, John P A

2016-01-01

The p-curve, the distribution of statistically significant p-values of published studies, has been used to make inferences on the proportion of true effects and on the presence of p-hacking in the published literature. We analyze the p-curve for observational research in the presence of p-hacking. We show by means of simulations that even with minimal omitted-variable bias (e.g., unaccounted confounding) p-curves based on true effects and p-curves based on null-effects with p-hacking cannot be reliably distinguished. We also demonstrate this problem using as practical example the evaluation of the effect of malaria prevalence on economic growth between 1960 and 1996. These findings call recent studies into question that use the p-curve to infer that most published research findings are based on true effects in the medical literature and in a wide range of disciplines. p-values in observational research may need to be empirically calibrated to be interpretable with respect to the commonly used significance threshold of 0.05. Violations of randomization in experimental studies may also result in situations where the use of p-curves is similarly unreliable.

Trends in scale and shape of survival curves.

Science.gov (United States)

Weon, Byung Mook; Je, Jung Ho

2012-01-01

The ageing of the population is an issue in wealthy countries worldwide because of increasing costs for health care and welfare. Survival curves taken from demographic life tables may help shed light on the hypotheses that humans are living longer and that human populations are growing older. We describe a methodology that enables us to obtain separate measurements of scale and shape variances in survival curves. Specifically, 'living longer' is associated with the scale variance of survival curves, whereas 'growing older' is associated with the shape variance. We show how the scale and shape of survival curves have changed over time during recent decades, based on period and cohort female life tables for selected wealthy countries. Our methodology will be useful for performing better tracking of ageing statistics and it is possible that this methodology can help identify the causes of current trends in human ageing.

Influence of pavement condition on horizontal curve safety.

Science.gov (United States)

Buddhavarapu, Prasad; Banerjee, Ambarish; Prozzi, Jorge A

2013-03-01

Crash statistics suggest that horizontal curves are the most vulnerable sites for crash occurrence. These crashes are often severe and many involve at least some level of injury due to the nature of the collisions. Ensuring the desired pavement surface condition is one potentially effective strategy to reduce the occurrence of severe accidents on horizontal curves. This study sought to develop crash injury severity models by integrating crash and pavement surface condition databases. It focuses on developing a causal relationship between pavement condition indices and severity level of crashes occurring on two-lane horizontal curves in Texas. In addition, it examines the suitability of the existing Skid Index for safety maintenance of two-lane curves. Significant correlation is evident between pavement condition and crash injury severity on two-lane undivided horizontal curves in Texas. Probability of a crash becoming fatal is appreciably sensitive to certain pavement indices. Data suggested that road facilities providing a smoother and more comfortable ride are vulnerable to severe crashes on horizontal curves. In addition, the study found that longitudinal skid measurement barely correlates with injury severity of crashes occurring on curved portions. The study recommends exploring the option of incorporating lateral friction measurement into Pavement Management System (PMS) databases specifically at curved road segments. Copyright © 2012 Elsevier Ltd. All rights reserved.

Anatomical curve identification

Science.gov (United States)

Bowman, Adrian W.; Katina, Stanislav; Smith, Joanna; Brown, Denise

2015-01-01

Methods for capturing images in three dimensions are now widely available, with stereo-photogrammetry and laser scanning being two common approaches. In anatomical studies, a number of landmarks are usually identified manually from each of these images and these form the basis of subsequent statistical analysis. However, landmarks express only a very small proportion of the information available from the images. Anatomically defined curves have the advantage of providing a much richer expression of shape. This is explored in the context of identifying the boundary of breasts from an image of the female torso and the boundary of the lips from a facial image. The curves of interest are characterised by ridges or valleys. Key issues in estimation are the ability to navigate across the anatomical surface in three-dimensions, the ability to recognise the relevant boundary and the need to assess the evidence for the presence of the surface feature of interest. The first issue is addressed by the use of principal curves, as an extension of principal components, the second by suitable assessment of curvature and the third by change-point detection. P-spline smoothing is used as an integral part of the methods but adaptations are made to the specific anatomical features of interest. After estimation of the boundary curves, the intermediate surfaces of the anatomical feature of interest can be characterised by surface interpolation. This allows shape variation to be explored using standard methods such as principal components. These tools are applied to a collection of images of women where one breast has been reconstructed after mastectomy and where interest lies in shape differences between the reconstructed and unreconstructed breasts. They are also applied to a collection of lip images where possible differences in shape between males and females are of interest. PMID:26041943

Curve fitting and modeling with splines using statistical variable selection techniques

Science.gov (United States)

Smith, P. L.

1982-01-01

The successful application of statistical variable selection techniques to fit splines is demonstrated. Major emphasis is given to knot selection, but order determination is also discussed. Two FORTRAN backward elimination programs, using the B-spline basis, were developed. The program for knot elimination is compared in detail with two other spline-fitting methods and several statistical software packages. An example is also given for the two-variable case using a tensor product basis, with a theoretical discussion of the difficulties of their use.

Calculation of magnetization curves and probability distribution for monoclinic and uniaxial systems

International Nuclear Information System (INIS)

Sobh, Hala A.; Aly, Samy H.; Yehia, Sherif

2013-01-01

We present the application of a simple classical statistical mechanics-based model to selected monoclinic and hexagonal model systems. In this model, we treat the magnetization as a classical vector whose angular orientation is dictated by the laws of equilibrium classical statistical mechanics. We calculate for these anisotropic systems, the magnetization curves, energy landscapes and probability distribution for different sets of relevant parameters and magnetic fields of different strengths and directions. Our results demonstrate a correlation between the most probable orientation of the magnetization vector, the system's parameters, and the external magnetic field. -- Highlights: ► We calculate magnetization curves and probability angular distribution of the magnetization. ► The magnetization curves are consistent with probability results for the studied systems. ► Monoclinic and hexagonal systems behave differently due to their different anisotropies

Lagrangian Curves on Spectral Curves of Monopoles

International Nuclear Information System (INIS)

Guilfoyle, Brendan; Khalid, Madeeha; Ramon Mari, Jose J.

2010-01-01

We study Lagrangian points on smooth holomorphic curves in TP 1 equipped with a natural neutral Kaehler structure, and prove that they must form real curves. By virtue of the identification of TP 1 with the space LE 3 of oriented affine lines in Euclidean 3-space, these Lagrangian curves give rise to ruled surfaces in E 3 , which we prove have zero Gauss curvature. Each ruled surface is shown to be the tangent lines to a curve in E 3 , called the edge of regression of the ruled surface. We give an alternative characterization of these curves as the points in E 3 where the number of oriented lines in the complex curve Σ that pass through the point is less than the degree of Σ. We then apply these results to the spectral curves of certain monopoles and construct the ruled surfaces and edges of regression generated by the Lagrangian curves.

Statistical improvement in detection level of gravitational microlensing events from their light curves

Science.gov (United States)

Ibrahim, Ichsan; Malasan, Hakim L.; Kunjaya, Chatief; Timur Jaelani, Anton; Puannandra Putri, Gerhana; Djamal, Mitra

2018-04-01

In astronomy, the brightness of a source is typically expressed in terms of magnitude. Conventionally, the magnitude is defined by the logarithm of received flux. This relationship is known as the Pogson formula. For received flux with a small signal to noise ratio (S/N), however, the formula gives a large magnitude error. We investigate whether the use of Inverse Hyperbolic Sine function (hereafter referred to as the Asinh magnitude) in the modified formulae could allow for an alternative calculation of magnitudes for small S/N flux, and whether the new approach is better for representing the brightness of that region. We study the possibility of increasing the detection level of gravitational microlensing using 40 selected microlensing light curves from the 2013 and 2014 seasons and by using the Asinh magnitude. Photometric data of the selected events are obtained from the Optical Gravitational Lensing Experiment (OGLE). We found that utilization of the Asinh magnitude makes the events brighter compared to using the logarithmic magnitude, with an average of about 3.42 × 10‑2 magnitude and an average in the difference of error between the logarithmic and the Asinh magnitude of about 2.21 × 10‑2 magnitude. The microlensing events OB140847 and OB140885 are found to have the largest difference values among the selected events. Using a Gaussian fit to find the peak for OB140847 and OB140885, we conclude statistically that the Asinh magnitude gives better mean squared values of the regression and narrower residual histograms than the Pogson magnitude. Based on these results, we also attempt to propose a limit in magnitude value for which use of the Asinh magnitude is optimal with small S/N data.

NormaCurve: a SuperCurve-based method that simultaneously quantifies and normalizes reverse phase protein array data.

Directory of Open Access Journals (Sweden)

Sylvie Troncale

Full Text Available MOTIVATION: Reverse phase protein array (RPPA is a powerful dot-blot technology that allows studying protein expression levels as well as post-translational modifications in a large number of samples simultaneously. Yet, correct interpretation of RPPA data has remained a major challenge for its broad-scale application and its translation into clinical research. Satisfying quantification tools are available to assess a relative protein expression level from a serial dilution curve. However, appropriate tools allowing the normalization of the data for external sources of variation are currently missing. RESULTS: Here we propose a new method, called NormaCurve, that allows simultaneous quantification and normalization of RPPA data. For this, we modified the quantification method SuperCurve in order to include normalization for (i background fluorescence, (ii variation in the total amount of spotted protein and (iii spatial bias on the arrays. Using a spike-in design with a purified protein, we test the capacity of different models to properly estimate normalized relative expression levels. The best performing model, NormaCurve, takes into account a negative control array without primary antibody, an array stained with a total protein stain and spatial covariates. We show that this normalization is reproducible and we discuss the number of serial dilutions and the number of replicates that are required to obtain robust data. We thus provide a ready-to-use method for reliable and reproducible normalization of RPPA data, which should facilitate the interpretation and the development of this promising technology. AVAILABILITY: The raw data, the scripts and the normacurve package are available at the following web site: http://microarrays.curie.fr.

Relationship between students’ motivation and their socio-demographic characteristics

Directory of Open Access Journals (Sweden)

Vesna Cigan

2014-12-01

Full Text Available This article presents the results of research on the relationship between indicators of intrinsic and extrinsic motivation in students attending higher education institutions, and their socio-demographic characteristics: the type of upper secondary education completed, secondary education grade point average, year of study, gender, and parents’ education.  The research was conducted in March 2012, through a survey questionnaire administered to a sample of 604 respondents. The questionnaire examined, among other things, students’ motivation for learning, self-assessment of motivation for learning English and further professional development, and self-assessment of overall satisfaction with the study programme.  According to the self-determination theory developed by Deci and Ryan (2000, intrinsic and extrinsic motivation are essential for undertaking any activity, including learning. As a social agent, each individual interacts with different social groups in an action-oriented set of circumstances, and develops his/her personality (CEFR. Social contexts that catalyse intrapersonal and interpersonal differences also have a significant influence on motivation. Gardner’s theory of motivation emphasizes the importance of social components and the extrinsic nature of instrumental and integrative ­orientation. Instrumental-integrative dichotomy was further developed by Dörnyei (1994: 279, who introduced a motivational framework consisting of three levels: the language level, the learner level and the learning situation level. Survey results show that the respondents are generally highly-motivated to learn, and that intrinsic motivation is predominant. Statistically significant differences were found between gender, secondary education grade point average, and year of study and the type and intensity of motivation, whereas the type of upper secondary education completed, and parents’ education, were not found to be statistically

Research on the achievement motivation levels of the amateur football players

Directory of Open Access Journals (Sweden)

Yalçın İlimdar

2017-01-01

Full Text Available This study was conducted to determine the achievement motivation levels of the amateur football players based upon the importance of motivation on the athletes’ successes. The research group comprises 243 voluntary amateur football players who actively participated in the competitions during 2016-2017 season in Elazig. In the study, “Sports-Specific Achievement Motivation Scale” that was developed by Willis (1982 and adapted to Turkish by Tiryaki and Godelek (1997 was used. The collected data were analyzed through SPSS 22 programme. The margin of error was accepted as p<0.05. The cronbach alpha value was found as ,78. Consequently; when the subscales of achievement motivation of the amateur soccer players participating in the study were analyzed with some variables, it was found that there was a statistically significant difference between those aged 22-24 years and those aged 25-27 years in approach success. In the team playing year variable, the statistical significance was found between the ones who have 1 year football history in the team and those who are 5 years or more in the approach success. It was observed the approach to achievement motivation increased as the experience of playing for a team increased. As for the year of working with a trainer variable, it was found that there was a statistically significant difference between those who had 1 year past with coach and those who had 2 years past with the motivation to avoid failure.

Growth Curves for Girls with Turner Syndrome

Directory of Open Access Journals (Sweden)

Fabio Bertapelli

2014-01-01

Full Text Available The objective of this study was to review the growth curves for Turner syndrome, evaluate the methodological and statistical quality, and suggest potential growth curves for clinical practice guidelines. The search was carried out in the databases Medline and Embase. Of 1006 references identified, 15 were included. Studies constructed curves for weight, height, weight/height, body mass index, head circumference, height velocity, leg length, and sitting height. The sample ranged between 47 and 1,565 (total = 6,273 girls aged 0 to 24 y, born between 1950 and 2006. The number of measures ranged from 580 to 9,011 (total = 28,915. Most studies showed strengths such as sample size, exclusion of the use of growth hormone and androgen, and analysis of confounding variables. However, the growth curves were restricted to height, lack of information about selection bias, limited distributional properties, and smoothing aspects. In conclusion, we observe the need to construct an international growth reference for girls with Turner syndrome, in order to provide support for clinical practice guidelines.

Multi-q pattern classification of polarization curves

Science.gov (United States)

Fabbri, Ricardo; Bastos, Ivan N.; Neto, Francisco D. Moura; Lopes, Francisco J. P.; Gonçalves, Wesley N.; Bruno, Odemir M.

2014-02-01

Several experimental measurements are expressed in the form of one-dimensional profiles, for which there is a scarcity of methodologies able to classify the pertinence of a given result to a specific group. The polarization curves that evaluate the corrosion kinetics of electrodes in corrosive media are applications where the behavior is chiefly analyzed from profiles. Polarization curves are indeed a classic method to determine the global kinetics of metallic electrodes, but the strong nonlinearity from different metals and alloys can overlap and the discrimination becomes a challenging problem. Moreover, even finding a typical curve from replicated tests requires subjective judgment. In this paper, we used the so-called multi-q approach based on the Tsallis statistics in a classification engine to separate the multiple polarization curve profiles of two stainless steels. We collected 48 experimental polarization curves in an aqueous chloride medium of two stainless steel types, with different resistance against localized corrosion. Multi-q pattern analysis was then carried out on a wide potential range, from cathodic up to anodic regions. An excellent classification rate was obtained, at a success rate of 90%, 80%, and 83% for low (cathodic), high (anodic), and both potential ranges, respectively, using only 2% of the original profile data. These results show the potential of the proposed approach towards efficient, robust, systematic and automatic classification of highly nonlinear profile curves.

The Quantitative Analysis on the Individual Characteristics of Urban Residents and Their Sport Consumption Motivation

Science.gov (United States)

Xianliang, Lei; Hongying, Yu

Using the questionnaire, mathematical statistics and entropy measurement methods, the quantitative relationship between the individual characteristics urban residents and their sports consumption motivation are studied. The results show that the most main sports consumption motivation of urban residents is fitness motivation and social motivation. Urban residents of different gender, age, education and income levels are different in regulating psychological motivation, rational consumption motivation and seeking common motivation.

RESEARCH ON HUMAN RESOURCES MOTIVATION AND SATISFACTION

Directory of Open Access Journals (Sweden)

Zoltan-Bela FARKAS

2014-06-01

Full Text Available Many research studies on the human resources performance of the educational system have proved that pupils/students’ educational success depends, to a high degree, on the level of human resource motivation, as well as on their degree of professional satisfaction. Teachers’ who show a high level of motivation, both intrinsic and extrinsic, invest more into their activity, are more creative and more efficient in problem solving. The paper debates the results of an empirical study regarding the influence of pre-university teachers’ motivation and satisfaction regarding the general work conditions on their work performance by measuring the present motivation and satisfaction level. Furthermore, the determinant factors of their satisfaction with the work place are determined and analyzed. Finally, based on the statistical data process we will conclude and debate on the research hypothesis validation and the empirical model related to motivation – satisfaction – performance interdependences.

Motivation of Academics: An Empirical Assessment of Herzberg's Theory

Science.gov (United States)

Saglam, Aycan Cicek

2007-01-01

This study examined academics' viewpoints according to sex, academic title, and professional seniority to establish how much the university presented to its staff hygiene and motivation factors and to find out the effect of these factors in motivating the staff. The findings show that there is not a statistical difference among the academics'…

Student Perceptions of Motivational Behaviors of Instructions in a Military Setting

Science.gov (United States)

2005-06-01

surveys of students, faculty, and alumni, (b) summaries of research, (c) theories of leading researchers, and (d) statistically identified factors. Three...habits, motivation, learning style, cogitative, socioemotional , and morale character development. Theoretical Framework of Motivation in Teacher...and not in others has been the subject of many theories McKeachie (2002). 23 McClelland, Atkinson, Clark, and Lowell (1953) stated that motivation

Econophysics: Master curve for price-impact function

Science.gov (United States)

Lillo, Fabrizio; Farmer, J. Doyne; Mantegna, Rosario N.

2003-01-01

The price reaction to a single transaction depends on transaction volume, the identity of the stock, and possibly many other factors. Here we show that, by taking into account the differences in liquidity for stocks of different size classes of market capitalization, we can rescale both the average price shift and the transaction volume to obtain a uniform price-impact curve for all size classes of firm for four different years (1995-98). This single-curve collapse of the price-impact function suggests that fluctuations from the supply-and-demand equilibrium for many financial assets, differing in economic sectors of activity and market capitalization, are governed by the same statistical rule.

A simple derivation of r* for curved exponential families

DEFF Research Database (Denmark)

Jensen, Jens Ledet

1997-01-01

For curved exponential families we consider modified likelihood ratio statistics of the form rL = r + log (u/r)/r, where r is the signed root of the likelihood ratio statistic. We are testing a one-dimensional hypothesis, but in order to specify approximate ancillary statistics we consider the test...... as one in a series of tests. By requiring asymptotic independence and asymptotic normality of the test statistics in a large deviation region there is a particular choice of the statistic u which suggests itself. The derivation of this result is quite simple, only involving a standard saddlepoint...... approximation followed by a transformation. We give explicit formulas for the statistic u, and include a discussion of the case where some coordinates of the underlying variable are lattice....

Intelligence, genes, and success scientists respond to the bell curve

CERN Document Server

Fienberg, Stephen; Resnick, Daniel; Roeder, Kathryn

1997-01-01

This is author-approved bcc. If it is too long, delete the last sentence in each of the biographies. THE BELL CURVE by Richard Herrnstein and Charles Murray, a best selling book published in 1994, set off a hailstorm of controversy about the relationships among IQ, genetics, and various social outcomes, including welfare dependency, crime, and earnings. Much of the public reaction to the book was polemical and did not focus on the details of the science and in particular on the validity of the statistical arguments that underlie the books's conclusions. A detailed understanding of the arguments in THE BELL CURVE requires knowledge about (i) statistical models for genetic heritability, (ii) factor analysis, especially as it has been applied to the analysis of IQ tests, (iii) logistic regression and multiple regression analyses,and (iv) causal modelling and alternative statistical frameworks for making inference from longitudinal data. In this volume a group of statisticians and social scientists have assembled...

Characterizing time series via complexity-entropy curves

Science.gov (United States)

Ribeiro, Haroldo V.; Jauregui, Max; Zunino, Luciano; Lenzi, Ervin K.

2017-06-01

The search for patterns in time series is a very common task when dealing with complex systems. This is usually accomplished by employing a complexity measure such as entropies and fractal dimensions. However, such measures usually only capture a single aspect of the system dynamics. Here, we propose a family of complexity measures for time series based on a generalization of the complexity-entropy causality plane. By replacing the Shannon entropy by a monoparametric entropy (Tsallis q entropy) and after considering the proper generalization of the statistical complexity (q complexity), we build up a parametric curve (the q -complexity-entropy curve) that is used for characterizing and classifying time series. Based on simple exact results and numerical simulations of stochastic processes, we show that these curves can distinguish among different long-range, short-range, and oscillating correlated behaviors. Also, we verify that simulated chaotic and stochastic time series can be distinguished based on whether these curves are open or closed. We further test this technique in experimental scenarios related to chaotic laser intensity, stock price, sunspot, and geomagnetic dynamics, confirming its usefulness. Finally, we prove that these curves enhance the automatic classification of time series with long-range correlations and interbeat intervals of healthy subjects and patients with heart disease.

Understanding the role of emotion-oriented coping in women's motivation for change.

Science.gov (United States)

Wu, Qiong; Slesnick, Natasha; Zhang, Jing

2018-03-01

This study tested a sequential mediation model that emotion-oriented coping and motivation for change mediate the relations between anxiety and depressive symptoms and the change in substance use. Data included 183 substance using women, randomly assigned to family therapy (N=123) or individual therapy (N=60). They reported their baseline anxiety and depressive symptoms, emotion-oriented coping, as well as motivation for change throughout treatment, and substance use over a time period of 1.5years. Latent growth curve modeling showed that increased baseline motivation was associated with a faster decline in alcohol and drug use. Moreover, higher baseline anxiety and depressive symptoms were associated with a faster decrease in drug use through higher emotion-oriented coping and higher baseline motivation. This study underscores the importance of emotion-oriented coping in increasing clients' motivation and reducing their drug use. Copyright © 2017 Elsevier Inc. All rights reserved.

Spline Trajectory Algorithm Development: Bezier Curve Control Point Generation for UAVs

Science.gov (United States)

Howell, Lauren R.; Allen, B. Danette

2016-01-01

A greater need for sophisticated autonomous piloting systems has risen in direct correlation with the ubiquity of Unmanned Aerial Vehicle (UAV) technology. Whether surveying unknown or unexplored areas of the world, collecting scientific data from regions in which humans are typically incapable of entering, locating lost or wanted persons, or delivering emergency supplies, an unmanned vehicle moving in close proximity to people and other vehicles, should fly smoothly and predictably. The mathematical application of spline interpolation can play an important role in autopilots' on-board trajectory planning. Spline interpolation allows for the connection of Three-Dimensional Euclidean Space coordinates through a continuous set of smooth curves. This paper explores the motivation, application, and methodology used to compute the spline control points, which shape the curves in such a way that the autopilot trajectory is able to meet vehicle-dynamics limitations. The spline algorithms developed used to generate these curves supply autopilots with the information necessary to compute vehicle paths through a set of coordinate waypoints.

Development of free statistical software enabling researchers to calculate confidence levels, clinical significance curves and risk-benefit contours

International Nuclear Information System (INIS)

Shakespeare, T.P.; Mukherjee, R.K.; Gebski, V.J.

2003-01-01

Confidence levels, clinical significance curves, and risk-benefit contours are tools improving analysis of clinical studies and minimizing misinterpretation of published results, however no software has been available for their calculation. The objective was to develop software to help clinicians utilize these tools. Excel 2000 spreadsheets were designed using only built-in functions, without macros. The workbook was protected and encrypted so that users can modify only input cells. The workbook has 4 spreadsheets for use in studies comparing two patient groups. Sheet 1 comprises instructions and graphic examples for use. Sheet 2 allows the user to input the main study results (e.g. survival rates) into a 2-by-2 table. Confidence intervals (95%), p-value and the confidence level for Treatment A being better than Treatment B are automatically generated. An additional input cell allows the user to determine the confidence associated with a specified level of benefit. For example if the user wishes to know the confidence that Treatment A is at least 10% better than B, 10% is entered. Sheet 2 automatically displays clinical significance curves, graphically illustrating confidence levels for all possible benefits of one treatment over the other. Sheet 3 allows input of toxicity data, and calculates the confidence that one treatment is more toxic than the other. It also determines the confidence that the relative toxicity of the most effective arm does not exceed user-defined tolerability. Sheet 4 automatically calculates risk-benefit contours, displaying the confidence associated with a specified scenario of minimum benefit and maximum risk of one treatment arm over the other. The spreadsheet is freely downloadable at www.ontumor.com/professional/statistics.htm A simple, self-explanatory, freely available spreadsheet calculator was developed using Excel 2000. The incorporated decision-making tools can be used for data analysis and improve the reporting of results of any

Nonparametric statistics with applications to science and engineering

CERN Document Server

Kvam, Paul H

2007-01-01

A thorough and definitive book that fully addresses traditional and modern-day topics of nonparametric statistics This book presents a practical approach to nonparametric statistical analysis and provides comprehensive coverage of both established and newly developed methods. With the use of MATLAB, the authors present information on theorems and rank tests in an applied fashion, with an emphasis on modern methods in regression and curve fitting, bootstrap confidence intervals, splines, wavelets, empirical likelihood, and goodness-of-fit testing. Nonparametric Statistics with Applications to Science and Engineering begins with succinct coverage of basic results for order statistics, methods of categorical data analysis, nonparametric regression, and curve fitting methods. The authors then focus on nonparametric procedures that are becoming more relevant to engineering researchers and practitioners. The important fundamental materials needed to effectively learn and apply the discussed methods are also provide...

Drinking motives and links to alcohol use in 13 European countries

NARCIS (Netherlands)

Kuntsche, E.N.; Gabhainn, S.N.; Roberts, C.; Windlin, B.; Vieno, A.; Bendtsen, P.; Hublet, A.; Tynjälä, J.; Välimaa, R.; Dankulincová, Z.; Aasvee, K.; Demetrovics, Z.; Farkas, J.; Sluijs, W. van der; Gaspar de Matos, M.; Mazur, J.; Wicki, M.

2014-01-01

Objective: The purpose of this study was to test the structure and endorsement of drinking motives and their links to alcohol use among 11- to 19-year-olds from 13 European countries. Method: Confirmatory factor analysis, latent growth curves, and multiple regression models were conducted, based on

Factors contributing to the nuclear caloric curve aspect

International Nuclear Information System (INIS)

Raduta, Al.H.; Raduta, Ad.R.

1999-01-01

After the first experimental evaluation of the nuclear caloric curve a large amount of theoretical work was concentrated to reproduce the transition-like plateau of the caloric curve from 5 MeV temperature. Both dynamical and statistical models have been employed in order to deduce the excitation energy dependence of the temperature of the equilibrated nuclear systems formed in violent heavy ion collisions. For describing such kind of systems a microcanonical model fully obeying the involved physical constrains seems to be the most appropriate option. However, the currently used statistical multifragmentation models (SMM and MMMC ) are not fully satisfying the microcanonical rules. For these reasons the nuclear caloric curve is studied in the present work from the point of view of a sharp microcanonical model. In this respect a detailed analysis concerning the contribution of the various energetic degrees of freedom (binding, Coulomb repulsive and internal excitation) to the curve aspect is performed. The method adopted here consists in suppressing each of the above-mentioned degrees of freedom once at a time keeping the rest of the system parameters unchanged. The Coulomb repulsive (V) and excitation (ε) degrees of freedom are suppressed by fixing the respective energies to zero. The binding degree of freedom (B) is 'suppressed' by fixing it to the constant value of - 8.5 MeV/nucleon for all fragments. The effect of the correlation between the Coulomb repulsive and the excitation degrees of freedom on the caloric curve aspect is also studied. The resulting caloric curves are denoted T -V , T -ε , T -B , T -Vε . One may observe that the suppression of the excitation degree of freedom has the effect of lifting and diminishing the plateau and the suppression of the Coulomb degree of freedom is lowering the plateau and almost washes-out the plateau-like region. The spectacular effect concerns the complementary moves T -Vε and - B: While the Vε couple suppression

A statistical study on fracture toughness data of Japanese RPVS

International Nuclear Information System (INIS)

Sakai, Y.; Ogura, N.

1987-01-01

In a cooperative study for investigating fracture toughness on pressure vessel steels produced in Japan, a number of heats of ASTM A533B cl.1 and A508 cl.3 steels have been studied. Approximately 3000 fracture toughness data and 8000 mechanical properties data were obtained and filed in a computer data bank. Statistical characterization of toughness data in the transition region has been carried out using the computer data bank. Curve fitting technique for toughness data has been examined. Approach using the function to model the transition behaviours of each toughness has been applied. The aims of fitting curve technique were as follows; (1) Summarization of an enormous toughness data base to permit comparison heats, materials and testing methods; (2) Investigating the relationships among static, dynamic and arrest toughness; (3) Examining the ASME K(IR) curve statistically. The methodology used in this study for analyzing a large quantity of fracture toughness data was found to be useful for formulating a statistically based K(IR) curve. (orig./HP)

Application of tan h curve fitting to toughness data

International Nuclear Information System (INIS)

Sakai, Yuzuru; Ogura, Nobukazu

1985-01-01

Curve-fitting regression procedures for toughness data have been examined. The objectives of fitting curve in the context of the study of nuclear pressure vessel steels are (1) convenient summarization of test data to permit comparison of materials and testing methods; (2) development of statistical base concerning the data; (3) the surveying of the relationships between charpy data and fracture toughness data; (4) estimation of fracture toughness level from charpy absorbed energy data. The computational procedures using the tanh function have been applied to the toughness data (charpy absorbed energy, static fracture toughness, dynamic fracture toughness, crack arrest toughness) of A533B cl.1 and A508 cl.3 steels. The results of the analysis shows the statistical features of the material toughness and gives the method for estimating fracture toughness level from charpy absorbed energy data. (author)

Computing daily mean streamflow at ungaged locations in Iowa by using the Flow Anywhere and Flow Duration Curve Transfer statistical methods

Science.gov (United States)

Linhart, S. Mike; Nania, Jon F.; Sanders, Curtis L.; Archfield, Stacey A.

2012-01-01

linear regression method and the daily mean streamflow for the 15th day of every other month. The Flow Duration Curve Transfer method was used to estimate unregulated daily mean streamflow from the physical and climatic characteristics of gaged basins. For the Flow Duration Curve Transfer method, daily mean streamflow quantiles at the ungaged site were estimated with the parameter-based regression model, which results in a continuous daily flow-duration curve (the relation between exceedance probability and streamflow for each day of observed streamflow) at the ungaged site. By the use of a reference streamgage, the Flow Duration Curve Transfer is converted to a time series. Data used in the Flow Duration Curve Transfer method were retrieved for 113 continuous-record streamgages in Iowa and within a 50-mile buffer of Iowa. The final statewide regression equations for Iowa were computed by using a weighted-least-squares multiple linear regression method and were computed for the 0.01-, 0.05-, 0.10-, 0.15-, 0.20-, 0.30-, 0.40-, 0.50-, 0.60-, 0.70-, 0.80-, 0.85-, 0.90-, and 0.95-exceedance probability statistics determined from the daily mean streamflow with a reporting limit set at 0.1 ft3/s. The final statewide regression equation for Iowa computed by using left-censored regression techniques was computed for the 0.99-exceedance probability statistic determined from the daily mean streamflow with a low limit threshold and a reporting limit set at 0.1 ft3/s. For the Flow Anywhere method, results of the validation study conducted by using six streamgages show that differences between the root-mean-square error and the mean absolute error ranged from 1,016 to 138 ft3/s, with the larger value signifying a greater occurrence of outliers between observed and estimated streamflows. Root-mean-square-error values ranged from 1,690 to 237 ft3/s. Values of the percent root-mean-square error ranged from 115 percent to 26.2 percent. The logarithm (base 10) streamflow percent root

Intrinsic motivation, neurocognition and psychosocial functioning in schizophrenia: testing mediator and moderator effects.

Science.gov (United States)

Nakagami, Eri; Xie, Bin; Hoe, Maanse; Brekke, John S

2008-10-01

This study examined the nature of the relationships among neurocognition, intrinsic motivation, and psychosocial functioning for persons with schizophrenia. Hypotheses concerning both mediator and moderator mechanisms were tested. 120 individuals diagnosed with schizophrenia were recruited as they entered outpatient psychosocial rehabilitation programs. Measures of psychosocial functioning and intrinsic motivation were administered at baseline. Measures of neurocognition were administered at baseline by testers blind to scores on other study variables. Data were analyzed using latent construct modeling to test for mediator and moderator effects. There were strong bivariate relationships between neurocognition, intrinsic motivation, and psychosocial functioning. The results demonstrated that intrinsic motivation strongly mediated the relationship between neurocognition and psychosocial functioning. This mediation was evidenced by: (i) the direct path from neurocognition to functional outcome no longer being statistically significant after the introduction of motivation into the model, (ii) the statistical significance of the indirect path from neurocognition through motivation to functional outcome. There was no support for the two moderation hypotheses: the level of neurocognition did not influence the relationship between intrinsic motivation and psychosocial functioning, nor did the level of intrinsic motivation influence the relationship between neurocognition and psychosocial functioning. Neurocognition influences psychosocial functioning through its relationship with intrinsic motivation. Intrinsic motivation is a critical mechanism for explaining the relationship between neurocognition and psychosocial functioning. Implications for the theoretical understanding and psychosocial treatment of intrinsic motivation in schizophrenia are discussed.

A heuristic for the distribution of point counts for random curves over a finite field.

Science.gov (United States)

Achter, Jeffrey D; Erman, Daniel; Kedlaya, Kiran S; Wood, Melanie Matchett; Zureick-Brown, David

2015-04-28

How many rational points are there on a random algebraic curve of large genus g over a given finite field Fq? We propose a heuristic for this question motivated by a (now proven) conjecture of Mumford on the cohomology of moduli spaces of curves; this heuristic suggests a Poisson distribution with mean q+1+1/(q-1). We prove a weaker version of this statement in which g and q tend to infinity, with q much larger than g. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Level Of Extension Agents Motivation And Effectiveness In Abia State Nigeria.

Directory of Open Access Journals (Sweden)

Machiadikwe N. Benjamin Agbarevo Nwogu

2015-08-01

Full Text Available Motivation is known to affect effectiveness of workers but the level of extension agents motivation and how this has affected their effectiveness in Abia state is apparently unknown. A study was therefore conducted to determine the effect of motivation on effectiveness of extension agents in Abia State Nigeria. Two blocks were selected from each of the three zones in the state at the first stage giving total of 6 blocks. The second stage involved the selection of two sub-circles from each of the 6 blocks selected giving a total of 12 extension sub-circles. At the third stage 10 extension agents from each of the sub-circles were randomly selected giving a sample size of 120 extension agents. The data for the study was collected with use of a structured questionnaire. The extension agents level of motivation and effectiveness were measured with the aid of a 5 point Likert rating scale. Data collected was analyzed using both descriptive and inferential statistics. Descriptive statistics used were the mean frequencies and the Pearsons Product Moment Correlation Co-efficient which was used to determine the coefficient of correlation r . The inferential statistic used was the t-test of significance of relationship. The study found a significant relationship between the level of motivation and effectiveness of extension agents. Hence the null hypothesis which stated that there is no significant relationship between the level of motivation and effectiveness of extension agents was rejected and the alternative hypothesis accepted at 95 confidence level and 119 degrees of freedom.

Analyzing Motives, Preferences, and Experiences in Video Game Play

Directory of Open Access Journals (Sweden)

Donald Loffredo

2017-04-01

Full Text Available This paper presents the results of analyzing motives, preferences, and experiences in video game play. A sample of 112 (64 male and 48 female students completed online the Gaming Attitudes, Motives, and Experiences Scales (GAMES. Separate one-way independent-measures multivariate analyses of variance (MANOVAs were used to determine if there were statistically significant differences by gender, age category, hours of videogame play, and ethnicity on the nine Factor Subscales of the GAMES. The results supported two of the proposed hypotheses. There were statistically differences by gender and hours of videogame play on some of the Factor Subscales of the GAMES.

Statistical Methods in Integrative Genomics

Science.gov (United States)

Richardson, Sylvia; Tseng, George C.; Sun, Wei

2016-01-01

Statistical methods in integrative genomics aim to answer important biology questions by jointly analyzing multiple types of genomic data (vertical integration) or aggregating the same type of data across multiple studies (horizontal integration). In this article, we introduce different types of genomic data and data resources, and then review statistical methods of integrative genomics, with emphasis on the motivation and rationale of these methods. We conclude with some summary points and future research directions. PMID:27482531

Greater Activity in the Frontal Cortex on Left Curves: A Vector-Based fNIRS Study of Left and Right Curve Driving.

Directory of Open Access Journals (Sweden)

Noriyuki Oka

Full Text Available In the brain, the mechanisms of attention to the left and the right are known to be different. It is possible that brain activity when driving also differs with different horizontal road alignments (left or right curves, but little is known about this. We found driver brain activity to be different when driving on left and right curves, in an experiment using a large-scale driving simulator and functional near-infrared spectroscopy (fNIRS.The participants were fifteen healthy adults. We created a course simulating an expressway, comprising straight line driving and gentle left and right curves, and monitored the participants under driving conditions, in which they drove at a constant speed of 100 km/h, and under non-driving conditions, in which they simply watched the screen (visual task. Changes in hemoglobin concentrations were monitored at 48 channels including the prefrontal cortex, the premotor cortex, the primary motor cortex and the parietal cortex. From orthogonal vectors of changes in deoxyhemoglobin and changes in oxyhemoglobin, we calculated changes in cerebral oxygen exchange, reflecting neural activity, and statistically compared the resulting values from the right and left curve sections.Under driving conditions, there were no sites where cerebral oxygen exchange increased significantly more during right curves than during left curves (p > 0.05, but cerebral oxygen exchange increased significantly more during left curves (p < 0.05 in the right premotor cortex, the right frontal eye field and the bilateral prefrontal cortex. Under non-driving conditions, increases were significantly greater during left curves (p < 0.05 only in the right frontal eye field.Left curve driving was thus found to require more brain activity at multiple sites, suggesting that left curve driving may require more visual attention than right curve driving. The right frontal eye field was activated under both driving and non-driving conditions.

Greater Activity in the Frontal Cortex on Left Curves: A Vector-Based fNIRS Study of Left and Right Curve Driving

Science.gov (United States)

Oka, Noriyuki; Yoshino, Kayoko; Yamamoto, Kouji; Takahashi, Hideki; Li, Shuguang; Sugimachi, Toshiyuki; Nakano, Kimihiko; Suda, Yoshihiro; Kato, Toshinori

2015-01-01

Objectives In the brain, the mechanisms of attention to the left and the right are known to be different. It is possible that brain activity when driving also differs with different horizontal road alignments (left or right curves), but little is known about this. We found driver brain activity to be different when driving on left and right curves, in an experiment using a large-scale driving simulator and functional near-infrared spectroscopy (fNIRS). Research Design and Methods The participants were fifteen healthy adults. We created a course simulating an expressway, comprising straight line driving and gentle left and right curves, and monitored the participants under driving conditions, in which they drove at a constant speed of 100 km/h, and under non-driving conditions, in which they simply watched the screen (visual task). Changes in hemoglobin concentrations were monitored at 48 channels including the prefrontal cortex, the premotor cortex, the primary motor cortex and the parietal cortex. From orthogonal vectors of changes in deoxyhemoglobin and changes in oxyhemoglobin, we calculated changes in cerebral oxygen exchange, reflecting neural activity, and statistically compared the resulting values from the right and left curve sections. Results Under driving conditions, there were no sites where cerebral oxygen exchange increased significantly more during right curves than during left curves (p > 0.05), but cerebral oxygen exchange increased significantly more during left curves (p right premotor cortex, the right frontal eye field and the bilateral prefrontal cortex. Under non-driving conditions, increases were significantly greater during left curves (p right frontal eye field. Conclusions Left curve driving was thus found to require more brain activity at multiple sites, suggesting that left curve driving may require more visual attention than right curve driving. The right frontal eye field was activated under both driving and non-driving conditions

Influence of science and technology magnet middle schools on students' motivation and achievement in science

Science.gov (United States)

Allen, David

Some informal discussions among educators regarding motivation of students and academic performance have included the topic of magnet schools. The premise is that a focused theme, such as an aspect of science, positively affects student motivation and academic achievement. However, there is limited research involving magnet schools and their influence on student motivation and academic performance. This study provides empirical data for the discussion about magnet schools influence on motivation and academic ability. This study utilized path analysis in a structural equation modeling framework to simultaneously investigate the relationships between demographic exogenous independent variables, the independent variable of attending a science or technology magnet middle school, and the dependent variables of motivation to learn science and academic achievement in science. Due to the categorical nature of the variables, Bayesian statistical analysis was used to calculate the path coefficients and the standardized effects for each relationship in the model. The coefficients of determination were calculated to determine the amount of variance each path explained. Only five of 21 paths had statistical significance. Only one of the five statistically significant paths (Attended Magnet School to Motivation to Learn Science) explained a noteworthy amount (45.8%) of the variance.

Why Wait? The Influence of Academic Self-Regulation, Intrinsic Motivation, and Statistics Anxiety on Procrastination in Online Statistics

Science.gov (United States)

Dunn, Karee

2014-01-01

Online graduate education programs are expanding rapidly. Many of these programs require a statistics course, resulting in an increasing need for online statistics courses. The study reported here grew from experiences teaching online, graduate statistics courses. In seeking answers on how to improve this class, I discovered that research has yet…

The effect of a motivational intervention on weight loss is moderated by level of baseline controlled motivation

Directory of Open Access Journals (Sweden)

Tate Deborah F

2010-01-01

Full Text Available Abstract Background Clinic-based behavioral weight loss programs are effective in producing significant weight loss. A one-size-fits-all approach is often taken with these programs. It may be beneficial to tailor programs based on participants' baseline characteristics. Type and level of motivation may be an important factor to consider. Previous research has found that, in general, higher levels of controlled motivation are detrimental to behavior change while higher levels of autonomous motivation improve the likelihood of behavior modification. Methods This study assessed the outcomes of two internet behavioral weight loss interventions and assessed the effect of baseline motivation levels on program success. Eighty females (M (SD age 48.7 (10.6 years; BMI 32.0 (3.7 kg/m2; 91% Caucasian were randomized to one of two groups, a standard group or a motivation-enhanced group. Both received a 16-week internet behavioral weight loss program and attended an initial and a four-week group session. Weight and motivation were measured at baseline, four and 16 weeks. Hierarchical regression analysis was conducted to test for moderation. Results There was significant weight loss at 16-weeks in both groups (p p = 0.57 (standard group 3.4 (3.6 kg; motivation-enhanced group 3.9 (3.4 kg. Further analysis was conducted to examine predictors of weight loss. Baseline controlled motivation level was negatively correlated with weight loss in the entire sample (r = -0.30; p = 0.01. Statistical analysis revealed an interaction between study group assignment and baseline level of controlled motivation. Weight loss was not predicted by baseline level of controlled motivation in the motivation-enhanced group, but was significantly predicted by controlled motivation in the standard group. Baseline autonomous motivation did not predict weight change in either group. Conclusions This research found that, in participants with high levels of baseline controlled motivation

The Practice of the Motivational Process in Contemporary Management

Directory of Open Access Journals (Sweden)

Tukhvatulina Liliya

2016-01-01

Full Text Available The purpose of this paper is to provide an analysis of the contemporary motivation system at the Russian enterprises. The purpose of the analysis is to find out the main motivators at the enterprises; to highlight the advantages and disadvantages of the existing motivation system and to predict the future development of the motivation system. The given research has been developed by using sociological methods, such as interviews, the analysis of the statistics and simulation method. By analyzing the existing works, the authors have identified the main motivators in connection with the management development periods. Tracing the features of these motivators, the authors have defined the period that corresponds to the incentive system at the Russian enterprises. In practical sphere, the proposed research can be used to develop the motivation system at the Russian enterprises, to make it effective and to predict the potential problems that can appear in the future.

SITE INDEX CURVES AND HYPSOMETRIC RELATIONSHIP FOR Eucalyptus grandis PLANTATIONS FOR THE CAMPOS GERAIS REGION, PARANA STATE

Directory of Open Access Journals (Sweden)

Fabiane Aparecida de Souza Retslaff

2015-06-01

Full Text Available The study aimed to fit mathematical models for the construction of Site Index curves and to estimate heights at different ages for Eucalyptus grandis in the Campos Gerais region, Parana State. The data used to fit the models came from permanent, temporary plots and pre-harvesting inventory, covering ages from 2.5 to 26.5 years. Several models were tested to represent the sites and the hypsometric relationship. The Site Index curves were constructed by the guide-curve method. For the Site Index, the Chapman-Richards model showed the best fit and precision statistics, generating 5 Site Index curves (range of 5 m with the Chapman-Richards model. The four hypsometric models tested showed satisfactory performance and similar statistics and the inclusion of the variables dominant height or site index did not substantially improve the goodness of fit statistics, but the residues were more homogeneous and closer to zero.

Statistical learning methods in high-energy and astrophysics analysis

Energy Technology Data Exchange (ETDEWEB)

Zimmermann, J. [Forschungszentrum Juelich GmbH, Zentrallabor fuer Elektronik, 52425 Juelich (Germany) and Max-Planck-Institut fuer Physik, Foehringer Ring 6, 80805 Munich (Germany)]. E-mail: zimmerm@mppmu.mpg.de; Kiesling, C. [Max-Planck-Institut fuer Physik, Foehringer Ring 6, 80805 Munich (Germany)

2004-11-21

We discuss several popular statistical learning methods used in high-energy- and astro-physics analysis. After a short motivation for statistical learning we present the most popular algorithms and discuss several examples from current research in particle- and astro-physics. The statistical learning methods are compared with each other and with standard methods for the respective application.

Statistical learning methods in high-energy and astrophysics analysis

International Nuclear Information System (INIS)

Zimmermann, J.; Kiesling, C.

2004-01-01

We discuss several popular statistical learning methods used in high-energy- and astro-physics analysis. After a short motivation for statistical learning we present the most popular algorithms and discuss several examples from current research in particle- and astro-physics. The statistical learning methods are compared with each other and with standard methods for the respective application

Characteristic of DTA curves for cast ferrous alloys

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S. Pietrowski

2008-04-01

Full Text Available The study presents DTA curves for selected grades of cast iron and cast steel. The thermal effects observed on derivative curves, caused by crystallisation of single phases and eutectic were discussed. The thermal effects having their origin in crystallisation of secondary carbides were determined. It has been indicated that the range of temperatures of their crystallisation can be determined from the cooling curve t = f(τ, from the solidification curve dt/dτ = f′(τ, and from the second derivative d2t/dτ2 = f″(τ. The crystallisation rate of single phases or of their mixture is indicated by the duration of thermal effect and by the slope angle of the curve responsible for a specific thermal effect before and after its maximum. A very high sensitivity of the derivative curve to temperature changes in liquid and solid alloy and to the phase (phases growth rate enables control of alloy before pouring of moulds. The control of alloy may consist in identification of phases the presence of which is indispensable in alloy microstructure and in determination of some important properties, e.g. Rp0,2, Rm, A5 and HB. In the latter case, the statistical relationships between the above mentioned characteristic parameters of DTA curves and the selected mechanical properties have been determined. The said relationships form a basis for construction of algorithms used in development of computer programs for control of individual alloys.

Rational Points on Curves of Genus 2: Experiments and Speculations

OpenAIRE

Stoll, Michael

2009-01-01

I will present results of computations providing statistics on rational points on (small) curves of genus 2 and use them to present several conjectures. Some of them are based on heuristic considerations, others are not.

Comparison of Paired ROC Curves through a Two-Stage Test.

Science.gov (United States)

Yu, Wenbao; Park, Eunsik; Chang, Yuan-Chin Ivan

2015-01-01

The area under the receiver operating characteristic (ROC) curve (AUC) is a popularly used index when comparing two ROC curves. Statistical tests based on it for analyzing the difference have been well developed. However, this index is less informative when two ROC curves cross and have similar AUCs. In order to detect differences between ROC curves in such situations, a two-stage nonparametric test that uses a shifted area under the ROC curve (sAUC), along with AUCs, is proposed for paired designs. The new procedure is shown, numerically, to be effective in terms of power under a wide range of scenarios; additionally, it outperforms two conventional ROC-type tests, especially when two ROC curves cross each other and have similar AUCs. Larger sAUC implies larger partial AUC at the range of low false-positive rates in this case. Because high specificity is important in many classification tasks, such as medical diagnosis, this is an appealing characteristic. The test also implicitly analyzes the equality of two commonly used binormal ROC curves at every operating point. We also apply the proposed method to synthesized data and two real examples to illustrate its usefulness in practice.

Better P-curves: Making P-curve analysis more robust to errors, fraud, and ambitious P-hacking, a Reply to Ulrich and Miller (2015).

Science.gov (United States)

Simonsohn, Uri; Simmons, Joseph P; Nelson, Leif D

2015-12-01

When studies examine true effects, they generate right-skewed p-curves, distributions of statistically significant results with more low (.01 s) than high (.04 s) p values. What else can cause a right-skewed p-curve? First, we consider the possibility that researchers report only the smallest significant p value (as conjectured by Ulrich & Miller, 2015), concluding that it is a very uncommon problem. We then consider more common problems, including (a) p-curvers selecting the wrong p values, (b) fake data, (c) honest errors, and (d) ambitiously p-hacked (beyond p < .05) results. We evaluate the impact of these common problems on the validity of p-curve analysis, and provide practical solutions that substantially increase its robustness. (c) 2015 APA, all rights reserved).

Dose-response curves from incomplete data

International Nuclear Information System (INIS)

Groer, P.G.

1978-01-01

Frequently many different responses occur in populations (animal or human) exposed to ionizing radiation. To obtain a dose-response curve, the exposed population is first divided into sub-groups whose members received the same radiation dose. To estimate the response, the fraction of subjects in each sub-group that showed the particular response of interest is determined. These fractions are plotted against dose to give the dose-response curve. This procedure of plotting the fractions versus the radiation dose is not the correct way to estimate the time distribution for a particular response at the different dose levels. Other observed responses competed for the individuals in the exposed population and therefore prevented manifestation of the complete information on the response-time distribution for one specific response. Such data are called incomplete in the statistical literature. A procedure is described which uses the by now classical Kaplan-Meier estimator, to establish dose-response curves from incomplete data under the assumption that the different observed responses are statistically independent. It is demonstrated that there is insufficient information in the observed survival functions to estimate the time distribution for one particular response if the assumption of independence is dropped. In addition, it is not possible to determine from the data (i.e. type of response and when it occurred) whether or not the different response-time distributions are independent. However, it is possible to give sharp bounds between which the response has to lie. This implies that for incomplete data, only a 'dose-response band' can be established if independence of the competing responses cannot be assumed. Examples are given using actual data to illustrate the estimation procedures

Quantifying and Reducing Curve-Fitting Uncertainty in Isc

Energy Technology Data Exchange (ETDEWEB)

Campanelli, Mark; Duck, Benjamin; Emery, Keith

2015-06-14

Current-voltage (I-V) curve measurements of photovoltaic (PV) devices are used to determine performance parameters and to establish traceable calibration chains. Measurement standards specify localized curve fitting methods, e.g., straight-line interpolation/extrapolation of the I-V curve points near short-circuit current, Isc. By considering such fits as statistical linear regressions, uncertainties in the performance parameters are readily quantified. However, the legitimacy of such a computed uncertainty requires that the model be a valid (local) representation of the I-V curve and that the noise be sufficiently well characterized. Using more data points often has the advantage of lowering the uncertainty. However, more data points can make the uncertainty in the fit arbitrarily small, and this fit uncertainty misses the dominant residual uncertainty due to so-called model discrepancy. Using objective Bayesian linear regression for straight-line fits for Isc, we investigate an evidence-based method to automatically choose data windows of I-V points with reduced model discrepancy. We also investigate noise effects. Uncertainties, aligned with the Guide to the Expression of Uncertainty in Measurement (GUM), are quantified throughout.

Flaws and fallacies in statistical thinking

CERN Document Server

Campbell, Stephen K

2004-01-01

This book was written with a dual purpose: first, the author was motivated to relieve his distress over the faulty conclusions drawn from the frequent misuse of relatively simple statistical tools such as percents, graphs, and averages. Second, his objective was to create a nontechnical book that would help people make better-informed decisions by increasing their ability to judge the quality of statistical evidence. This volume achieves both, serving as a supplemental text for students taking their first course in statistics, and as a self-help guide for anyone wishing to evaluate statistica

Energy dependence of contrast-detail-dose and object-detectability-dose curves for CT scanners

International Nuclear Information System (INIS)

Wagner, L.K.; Cohen, G.

1982-01-01

The energy dependence of contrast-detail-dose (CdD) and object-detectability-dose (OdD) curves for computed tomographic scanners is investigated. The effects of changes in beam energy on perceptibility are shown to be due to changes in signal-to-noise ratio resulting from changes in contrast and photon statistics. Energy-dependence analysis of OdD curves is shown to depend on the atomic composition of the phantom used to generate the curves, while such an analysis of CdD curves is independent of the atomic composition of the phantom. It is also shown that any OdD curve can be generated from CdD curves and that use of this fact rectifies any potential energy-dependent interpretation of CdD curves

Modelling precipitation extremes in the Czech Republic: update of intensity–duration–frequency curves

Directory of Open Access Journals (Sweden)

Michal Fusek

2016-11-01

Full Text Available Precipitation records from six stations of the Czech Hydrometeorological Institute were subject to statistical analysis with the objectives of updating the intensity–duration–frequency (IDF curves, by applying extreme value distributions, and comparing the updated curves against those produced by an empirical procedure in 1958. Another objective was to investigate differences between both sets of curves, which could be explained by such factors as different measuring instruments, measuring stations altitudes and data analysis methods. It has been shown that the differences between the two sets of IDF curves are significantly influenced by the chosen method of data analysis.

Statistical mechanics of solitons

International Nuclear Information System (INIS)

Bishop, A.

1980-01-01

The status of statistical mechanics theory (classical and quantum, statics and dynamics) is reviewed for 1-D soliton or solitary-wave-bearing systems. Primary attention is given to (i) perspective for existing results with evaluation and representative literature guide; (ii) motivation and status report for remaining problems; (iii) discussion of connections with other 1-D topics

Are health workers motivated by income? Job motivation of Cambodian primary health workers implementing performance-based financing.

Science.gov (United States)

Khim, Keovathanak

2016-01-01

Financial incentives are widely used in performance-based financing (PBF) schemes, but their contribution to health workers' incomes and job motivation is poorly understood. Cambodia undertook health sector reform from the middle of 2009 and PBF was employed as a part of the reform process. This study examines job motivation for primary health workers (PHWs) under PBF reform in Cambodia and assesses the relationship between job motivation and income. A cross-sectional self-administered survey was conducted on 266 PHWs, from 54 health centers in the 15 districts involved in the reform. The health workers were asked to report all sources of income from public sector jobs and provide answers to 20 items related to job motivation. Factor analysis was conducted to identify the latent variables of job motivation. Factors associated with motivation were identified through multivariable regression. PHWs reported multiple sources of income and an average total income of US$190 per month. Financial incentives under the PBF scheme account for 42% of the average total income. PHWs had an index motivation score of 4.9 (on a scale from one to six), suggesting they had generally high job motivation that was related to a sense of community service, respect, and job benefits. Regression analysis indicated that income and the perception of a fair distribution of incentives were both statistically significant in association with higher job motivation scores. Financial incentives used in the reform formed a significant part of health workers' income and influenced their job motivation. Improving job motivation requires fixing payment mechanisms and increasing the size of incentives. PBF is more likely to succeed when income, training needs, and the desire for a sense of community service are addressed and institutionalized within the health system.

Effect of Motivational Interviewing on a Weight Loss Program Based on the Protection Motivation Theory.

Science.gov (United States)

Mirkarimi, Kamal; Mostafavi, Firoozeh; Eshghinia, Samira; Vakili, Mohammad Ali; Ozouni-Davaji, Rahman Berdi; Aryaie, Mohammad

2015-06-01

The prevalence of overweight and obesity is on the increase the world over, which imposes an ever-increasing burden on societies and health care systems. This study sought to investigate the effect of motivational interviewing (MI) on a weight-loss program based on the protection motivation theory (PMT). This randomized clinical trial study, comprising pretest-posttest with a control group, was conducted on 150 overweight and obese women attending a private nutrition clinic for the first time. Samples were randomly selected using the clinic's records and then allocated to three groups (50 women in each group) receiving: 1) a standard weight-control program; 2) motivational interviewing; and 3) MI plus intention intervention. Data were collected using a researcher-made questionnaire through in-person interviews and were analyzed using SPSS (version 11) and statistical tests, including the Kruskal-Wallis test, one-way analysis of variance, paired t-test, and linear regression model. In the two intervention groups, the PMT construct scores, namely susceptibility (P = 0.001), severity (P = 0.001), rewards (P =0.004), self-efficacy (P = 0.001), response efficacy (P = 0.001), and costs (P = 0.014), were significantly increased compared to those in the control group. The anthropometric status was statistically significant in the MI group (P = 0.001) and the MI plus intention-intervention group (P = 0.001) at 2 months' follow-up, while in the control group, weight was meaningfully different after the intervention (P = 0.027). Weight was different between the groups after the intervention, with the Tukey test demonstrating that the differences were statistically significant between the control group and the MI group. Our results demonstrated that MI, combined with the implementation of intention intervention, increased weight loss and PMT construct scores in our study population.

The Influence of Motivation of Public Officials on their Corrupt Behavior in the System of Public Authority

Directory of Open Access Journals (Sweden)

Юлий Анатольевич Нисневич

2016-12-01

Full Text Available The article analyzes the influence of motivation of public officials on their corrupt behavior. In the framework of normative-value conceptualization corruption is considered as anti-social, auto-destructive deviant behavior. The represented two-dimensional curve of motivation consists of two segments. The first, “thirst for recognition” segment consists of pro-social, positive and altruistic motives, and the second, “greed” segment consists of negative and selfish motives. This article shows that motivation, especially with external locus of control has a decisive influence on corrupt behavior as means of the goals achievement. Particularly, it directly allows public officials to use “aim justifies the means” principle, or indirectly predetermine the very aim of their actions.

Effects of consumer motives on search behavior using internet advertising.

Science.gov (United States)

Yang, Kenneth C C

2004-08-01

Past studies on uses and gratifications theory suggested that consumer motives affect how they will use media and media contents. Recent advertising research has extended the theory to study the use of Internet advertising. The current study explores the effects of consumer motives on their search behavior using Internet advertising. The study employed a 2 by 2 between-subjects factorial experiment design. A total of 120 subjects were assigned to an experiment condition that contains an Internet advertisement varying by advertising appeals (i.e., rational vs. emotional) and product involvement levels (high vs. low). Consumer search behavior (measured by the depth, breadth, total amount of search), demographics, and motives were collected by post-experiment questionnaires. Because all three dependent variables measuring search behavior were conceptually related to each other, MANCOVA procedures were employed to examine the moderating effects of consumer motives on the dependent variables in four product involvement-advertising appeal conditions. Results indicated that main effects for product involvements and advertising appeals were statistically significant. Univariate ANOVA also showed that advertising appeals and product involvement levels influenced the total amount of search. Three-way interactions among advertising appeals, product involvement levels, and information motive were also statistically significant. Implications and future research directions are discussed.

Managerial level, managerial motivation and sense of coherence

Directory of Open Access Journals (Sweden)

MG Coetzee

2006-04-01

Full Text Available The first objective of the study was to assess whether the dimensions of Antonovsky’s Sense of Coherence (SOC scale correlated positively with those of the Managerial Motivation scale (MMQ. The second objective was to establish whether managers and supervisors differed with regard to sense of coherence and managerial motivation. The respondents were 124 employees of the Agricultural Research Council. None of the sense of coherence scales correlated with Attitude towards authority figures (MMQ. Also, Meaningfulness (SOC and Willingness to conduct administrative functions (MMQ did not correlate. However, the remainder of the correlations supported the hypothesis, indicating a strong positive relationship between managerial motivation and sense of coherence. Statistically significant differences between managers and supervisors were obtained for only two variables, namely Meaningfulness (SOC and Power motive (MMQ.

Examining Procrastination Across Multiple Goal Stages: A Longitudinal Study of Temporal Motivation Theory

Directory of Open Access Journals (Sweden)

Piers Steel

2018-04-01

Full Text Available Procrastination is among the most common of motivational failures, putting off despite expecting to be worse off. We examine this dynamic phenomenon in a detailed and realistic longitudinal design (Study 1 as well as in a large correlational data set (N = 7400; Study 2. The results are largely consistent with temporal motivation theory. People’s pacing style reflects a hyperbolic curve, with the steepness of the curve predicted by self-reported procrastination. Procrastination is related to intention-action gaps, but not intentions. Procrastinators are susceptible to proximity of temptation and to the temporal separation between their intention and the planned act; the more distal, the greater the gap. Critical self-regulatory skills in explaining procrastination are attention control, energy regulation and automaticity, accounting for 74% of the variance. Future research using this design is recommended, as it provides an almost ideal blend of realism and detailed longitudinal assessment.

Examining Procrastination Across Multiple Goal Stages: A Longitudinal Study of Temporal Motivation Theory.

Science.gov (United States)

Steel, Piers; Svartdal, Frode; Thundiyil, Tomas; Brothen, Thomas

2018-01-01

Procrastination is among the most common of motivational failures, putting off despite expecting to be worse off. We examine this dynamic phenomenon in a detailed and realistic longitudinal design (Study 1) as well as in a large correlational data set ( N = 7400; Study 2). The results are largely consistent with temporal motivation theory. People's pacing style reflects a hyperbolic curve, with the steepness of the curve predicted by self-reported procrastination. Procrastination is related to intention-action gaps, but not intentions. Procrastinators are susceptible to proximity of temptation and to the temporal separation between their intention and the planned act; the more distal, the greater the gap. Critical self-regulatory skills in explaining procrastination are attention control, energy regulation and automaticity, accounting for 74% of the variance. Future research using this design is recommended, as it provides an almost ideal blend of realism and detailed longitudinal assessment.

Modelling curves of manufacturing feasibilities and demand

Directory of Open Access Journals (Sweden)

Soloninko K.S.

2017-03-01

analysis and in the construction of models of curves according to statistical data. The methods of the study can also be applied to determine the functional properties for curves of supply.

Improving Statistical Literacy in Schools in Australia

OpenAIRE

Trewin, Dennis

2005-01-01

We live in the information age. Statistical thinking is a life skill that all Australian children should have. The Statistical Society of Australia (SSAI) and the Australian Bureau of Statistics (ABS) have been working on a strategy to ensure Australian school children acquire a sufficient understanding and appreciation of how data can be acquired and used so they can make informed judgements in their daily lives, as children and then as adults. There is another motive for our work i...

Motivation and motoric tests in sports.

Science.gov (United States)

Karaba-Jakovljević, Dea; Popadić-Gaćesa, Jelena; Grujić, Nikola; Barak, Otto; Drapsin, Miodrag

2007-01-01

Motivation in sport performance has been an interesting topic for many investigators during the past decade. This area can be considered from different viewpoints: motivation for participation in sport activity, achievement motivation, competitiveness etc. Motivation plays an important role in all out tests, as well as in sport activities and at all levels of competition. Motivation climate, or positive social environment may influence and modulate motivation of individuals involved in sports. Experience has shown that conventional encouragement and feedback during the test may affect its outcome. According to Wingate research team recommendations, verbal encouragement, as a motivation factor, was given to all examined subjects during Wingate anaerobic test, which is considered the most reliable test for assessing anaerobic capacity. The investigated group consisted of 30 young men--medical students, who were not actively involved in any programmed sport activity. The investigated group included second-year students of the Faculty of Medicine in Novi Sad chosen by random sampling. The Wingate anaerobic test was performed in all subjects, and changes of parameters when test was performed with verbal encouragement, were recorded The results show statistically significant increase of Wingate test parameters when conducted with verbal encouragement: anaerobic power (622/669 W); relative anaerobic power (7.70/8.27 W/kg); slope of the power (95.5/114 W/s); relative slope of the power (1.18/1.40 W/s/kg); anaerobic capacity (12.7/13.2 kJ) and relative anaerobic capacity (158/164 J/kg).

A residual life prediction model based on the generalized σ -N curved surface

Directory of Open Access Journals (Sweden)

Zongwen AN

2016-06-01

Full Text Available In order to investigate change rule of the residual life of structure under random repeated load, firstly, starting from the statistic meaning of random repeated load, the joint probability density function of maximum stress and minimum stress is derived based on the characteristics of order statistic (maximum order statistic and minimum order statistic; then, based on the equation of generalized σ -N curved surface, considering the influence of load cycles number on fatigue life, a relationship among minimum stress, maximum stress and residual life, that is the σmin(n- σmax(n-Nr(n curved surface model, is established; finally, the validity of the proposed model is demonstrated by a practical case. The result shows that the proposed model can reflect the influence of maximum stress and minimum stress on residual life of structure under random repeated load, which can provide a theoretical basis for life prediction and reliability assessment of structure.

Statistical methods for physical science

CERN Document Server

Stanford, John L

1994-01-01

This volume of Methods of Experimental Physics provides an extensive introduction to probability and statistics in many areas of the physical sciences, with an emphasis on the emerging area of spatial statistics. The scope of topics covered is wide-ranging-the text discusses a variety of the most commonly used classical methods and addresses newer methods that are applicable or potentially important. The chapter authors motivate readers with their insightful discussions, augmenting their material withKey Features* Examines basic probability, including coverage of standard distributions, time s

Wind energy statistics

International Nuclear Information System (INIS)

Holttinen, H.; Tammelin, B.; Hyvoenen, R.

1997-01-01

The recording, analyzing and publishing of statistics of wind energy production has been reorganized in cooperation of VTT Energy, Finnish Meteorological (FMI Energy) and Finnish Wind Energy Association (STY) and supported by the Ministry of Trade and Industry (KTM). VTT Energy has developed a database that contains both monthly data and information on the wind turbines, sites and operators involved. The monthly production figures together with component failure statistics are collected from the operators by VTT Energy, who produces the final wind energy statistics to be published in Tuulensilmae and reported to energy statistics in Finland and abroad (Statistics Finland, Eurostat, IEA). To be able to verify the annual and monthly wind energy potential with average wind energy climate a production index in adopted. The index gives the expected wind energy production at various areas in Finland calculated using real wind speed observations, air density and a power curve for a typical 500 kW-wind turbine. FMI Energy has produced the average figures for four weather stations using the data from 1985-1996, and produces the monthly figures. (orig.)

Research On: Motivation to Learn English among College Students in Sudan

Science.gov (United States)

Humaida, Ibrahim Abdelrahim Ibrahim

2012-01-01

This research was conducted to achieve the following objectives: to examine motivation to learn English language among students of faculty of arts, Islamic University-Sudan, to find out if there were significant statistical differences on motivation scores related to both student level and age. To pursue these objectives, the researcher used the…

Students' motivation and academic success in inclusive classes

Directory of Open Access Journals (Sweden)

Ilić-Stošović Danijela D.

2016-01-01

Full Text Available The analysis of the motivation experiences of students in the conditions of inclusive education determines teaching procedures considerably. The main aim of this research was to determine whether there were any difference in motivation experience between students with learning and developmental difficulties and the students without these difficulties, and whether there is any correlation of academic success and motivation experiences between these two groups. The sample comprised 87 students of the fifth grade (24.13% students with learning and developmental difficulties, and 75.86% students without these difficulties. The examination of motivation experience was carried out by the Scale for Estimating Extrinsic and Intrinsic Motivation. Statistics analyses show that there are differences in experiencing intrinsic and extrinsic motivation among students with and without learning and developmental difficulties. Learning difficulties correlate with lower academic achievement at the end of the fourth grade. As academic success increases the motivation experience decreases in both groups. The obtained results stress the importance of interventions by teachers and other school professionals in order to maintain motivational levels of all students. The results of this research highlight the quality of assessment system of academic achievement of all students and suggest further researching how and which way teachers understand and apply different functions of assessment.

Incorporating experience curves in appliance standards analysis

International Nuclear Information System (INIS)

Desroches, Louis-Benoit; Garbesi, Karina; Kantner, Colleen; Van Buskirk, Robert; Yang, Hung-Chia

2013-01-01

There exists considerable evidence that manufacturing costs and consumer prices of residential appliances have decreased in real terms over the last several decades. This phenomenon is generally attributable to manufacturing efficiency gained with cumulative experience producing a certain good, and is modeled by an empirical experience curve. The technical analyses conducted in support of U.S. energy conservation standards for residential appliances and commercial equipment have, until recently, assumed that manufacturing costs and retail prices remain constant during the projected 30-year analysis period. This assumption does not reflect real market price dynamics. Using price data from the Bureau of Labor Statistics, we present U.S. experience curves for room air conditioners, clothes dryers, central air conditioners, furnaces, and refrigerators and freezers. These experience curves were incorporated into recent energy conservation standards analyses for these products. Including experience curves increases the national consumer net present value of potential standard levels. In some cases a potential standard level exhibits a net benefit when considering experience, whereas without experience it exhibits a net cost. These results highlight the importance of modeling more representative market prices. - Highlights: ► Past appliance standards analyses have assumed constant equipment prices. ► There is considerable evidence of consistent real price declines. ► We incorporate experience curves for several large appliances into the analysis. ► The revised analyses demonstrate larger net present values of potential standards. ► The results imply that past standards analyses may have undervalued benefits.

Evaluation of the uncertainty for the efficiency curve determination of 210Pb by liquid scintillation

International Nuclear Information System (INIS)

Sampaio, C.S.; Sousa, W.O.; Dantas, B.M.

2014-01-01

Methodologies for the evaluation of uncertainties associated with the determination of the efficiency curve of 210 Pb by liquid scintillation counting (LSC) are presented. No statistical difference were found when compared the uncertainties of the curves that represented the counting net before and after the secular equilibrium between 210 Pb and 210 Bi, nether when compared the curves when counting only 210 Pb and the curve with the total count of 210 Pb and 210 Bi, for the same time interval after precipitation. (author)

Application of risk curve for statistical analysis of backside corrosion in the bottom floors of oil storage tanks

International Nuclear Information System (INIS)

Kasai, Naoya; Maeda, Takuma; Tamura, Koichi; Kitsukawa, Shigeo; Sekine, Kazuyoshi

2016-01-01

Overall thickness profile data for backside corrosion of the bottom floors of 17 oil storage tanks were collected, and a risk curve from the overall thickness profile and discrete thickness data was derived to evaluate the corrosion risk of the bottom floors. The slope of the risk curve in the large corrosion region was found to indicate the local corrosion condition. Parameters for evaluating localized corrosion derived from the corrosion distributions were also investigated to evaluate the corrosion risk of the bottom floors. Compared with the parameters obtained using the overall thickness profile and discrete thickness data, the slope of the risk curve is an excellent evaluation parameter using discrete thickness data. Thus, it is possible to accurately evaluate the corrosion characteristics of the bottom floors of oil storage tanks with the parameters obtained from discrete thickness data. - Highlights: • The risk curves for corrosion show the corrosion characteristic. • The obtained parameters indicate the corrosion characteristic. • The corrosion characteristic can be evaluated with discrete thickness data.

A residual life prediction model based on the generalized σ -N curved surface

OpenAIRE

Zongwen AN; Xuezong BAI; Jianxiong GAO

2016-01-01

In order to investigate change rule of the residual life of structure under random repeated load, firstly, starting from the statistic meaning of random repeated load, the joint probability density function of maximum stress and minimum stress is derived based on the characteristics of order statistic (maximum order statistic and minimum order statistic); then, based on the equation of generalized σ -N curved surface, considering the influence of load cycles number on fatigue life, a relation...

[Sucrose reward promotes rats' motivation for cocaine].

Science.gov (United States)

Li, Yan-Qing; LE, Qiu-Min; Yu, Xiang-Chen; Ma, Lan; Wang, Fei-Fei

2016-06-25

Caloric diet, such as fat and sugar intake, has rewarding effects, and has been indicated to affect the responses to addictive substances in animal experiments. However, the possible association between sucrose reward and the motivation for addictive drugs remains to be elucidated. Thus, we carried out behavioral tests after sucrose self-administration training to determine the effects of sucrose experience on rats' motivation for cocaine, locomotor sensitivity to cocaine, basal locomotor activity, anxiety level, and associative learning ability. The sucrose-experienced (sucrose) group exhibited higher lever press, cocaine infusion and break point, as well as upshift of cocaine dose-response curve in cocaine self-administration test, as compared with the control (chow) group. Additionally, despite similar locomotor activity in open field test and comparable score in cocaine-induced conditioned place preference, the sucrose group showed higher cocaine-induced locomotor sensitivity as compared with the chow group. The anxiety level and the performance in vocal-cue induced fear memory were similar between these two groups in elevated plus maze and fear conditioning tests, respectively. Taken together, our work indicates that sucrose experience promotes the rats' motivation for cocaine.

Learning curve of thyroid fine-needle aspiration biopsy.

Science.gov (United States)

Penín, Manuel; Martín, M Ángeles; San Millán, Beatriz; García, Juana

2017-12-01

Fine-needle aspiration biopsy (FNAB) is the reference procedure for thyroid nodule evaluation. Its main limitation are inadequate samples, which should be less than 20%. To analyze the learning curve of the procedure by comparing the results of a non-experienced endocrinologist (endocrinologist 2) to those of an experienced one (endocrinologist 1). Sixty FNABs were analyzed from February to June 2016. Each endocrinologist made 2punctures of every nodule in a random order. This order and the professional making every puncture were unknown to the pathologist who examined the samples. Endocrinologist 1 had a higher percentage of diagnoses than endocrinologist 2 (82% vs. 72%, P=.015). In the first 20 FNABs, the difference between both physicians was remarkable and statistically significant (80% vs. 50%, P=.047). In the following 20 FNABs, the difference narrowed and was not statistically significant (90% vs. 65%, P=.058). In the final 20 FNABs, the difference was minimal and not statistically significant (75% vs. 70%, P=.723). The learning curve of ultrasound-guided FNAB may be completed in a suitable environment by performing it at least 60 times. Although the guidelines recommend at least 3punctures per nodule, 2are enough to achieve an accurate percentage of diagnoses. Copyright © 2017 SEEN y SED. Publicado por Elsevier España, S.L.U. All rights reserved.

Foundations and applications of statistics an introduction using R

CERN Document Server

Pruim, Randall

2011-01-01

Foundations and Applications of Statistics simultaneously emphasizes both the foundational and the computational aspects of modern statistics. Engaging and accessible, this book is useful to undergraduate students with a wide range of backgrounds and career goals. The exposition immediately begins with statistics, presenting concepts and results from probability along the way. Hypothesis testing is introduced very early, and the motivation for several probability distributions comes from p-value computations. Pruim develops the students' practical statistical reasoning through explicit example

Weighted curve-fitting program for the HP 67/97 calculator

International Nuclear Information System (INIS)

Stockli, M.P.

1983-01-01

The HP 67/97 calculator provides in its standard equipment a curve-fit program for linear, logarithmic, exponential and power functions that is quite useful and popular. However, in more sophisticated applications, proper weights for data are often essential. For this purpose a program package was created which is very similar to the standard curve-fit program but which includes the weights of the data for proper statistical analysis. This allows accurate calculation of the uncertainties of the fitted curve parameters as well as the uncertainties of interpolations or extrapolations, or optionally the uncertainties can be normalized with chi-square. The program is very versatile and allows one to perform quite difficult data analysis in a convenient way with the pocket calculator HP 67/97

[The Significance of Work Motivation for Rehabilitation Success].

Science.gov (United States)

Kessemeier, Franziska; Stöckler, Christiane; Petermann, Franz; Bassler, Markus; Pfeiffer, Wolfgang; Kobelt, Axel

2017-11-28

Aim of this study Apart from the reduction of symptoms and the restoration of working ability, return to work is a long-term goal of medical rehabilitation. The aim of this study is to analyze the influence of work motivation on the outcome of rehabilitation. Methods The data basis consists of N=998 patients at the psychosomatic department of the Oberharz Rehabilitation Center as well as data from insurance accounts. Using multiple linear regression analysis the predictive power of work motivation on rehabilitation outcome as well as different facets of work motivation in their function as predictors are analyzed. Results Only minor statistical relations could be found between work motivation and rehabilitation success when also taking employment status of the previous year and subjective vocational disability into account. A small predictive power can be attributed to work motivation as a factor in rehabilitation success in the sense of a reduction of symptoms. Particular facets of work motivation are suitable to predict rehabilitation success. Patients with a work motivation risk profile differ from patients with a normal work motivation profile as regards their capacity to work in the year following rehabilitation treatment. Conclusion Work motivation represents a relevant construct in rehabilitation success but is strongly influenced by individual factors. During rehabilitation, individual problems which influence work motivation should be taken into account more strongly. © Georg Thieme Verlag KG Stuttgart · New York.

MOTIVATION

Institute of Scientific and Technical Information of China (English)

1994-01-01

Introduction What is the difference between instrumental and integrative motivation? What kind of motivations do students have? How can our knowledge of motivation help the language learning process? Motivation can be very important in language teaching. Students can do very well when they are motivated. Teachers, with their knowledge of motivation, can make their classes more efficient and successful. Middle school teachers, in addition to learning about the English language itself, and about teaching methods, should also learn more about motivation and how this affects our students. "When we consider language teaching, motivation can be classified as either integrative or instrumental motivation" (Luxon)

Exposure time independent summary statistics for assessment of drug dependent cell line growth inhibition.

Science.gov (United States)

Falgreen, Steffen; Laursen, Maria Bach; Bødker, Julie Støve; Kjeldsen, Malene Krag; Schmitz, Alexander; Nyegaard, Mette; Johnsen, Hans Erik; Dybkær, Karen; Bøgsted, Martin

2014-06-05

In vitro generated dose-response curves of human cancer cell lines are widely used to develop new therapeutics. The curves are summarised by simplified statistics that ignore the conventionally used dose-response curves' dependency on drug exposure time and growth kinetics. This may lead to suboptimal exploitation of data and biased conclusions on the potential of the drug in question. Therefore we set out to improve the dose-response assessments by eliminating the impact of time dependency. First, a mathematical model for drug induced cell growth inhibition was formulated and used to derive novel dose-response curves and improved summary statistics that are independent of time under the proposed model. Next, a statistical analysis workflow for estimating the improved statistics was suggested consisting of 1) nonlinear regression models for estimation of cell counts and doubling times, 2) isotonic regression for modelling the suggested dose-response curves, and 3) resampling based method for assessing variation of the novel summary statistics. We document that conventionally used summary statistics for dose-response experiments depend on time so that fast growing cell lines compared to slowly growing ones are considered overly sensitive. The adequacy of the mathematical model is tested for doxorubicin and found to fit real data to an acceptable degree. Dose-response data from the NCI60 drug screen were used to illustrate the time dependency and demonstrate an adjustment correcting for it. The applicability of the workflow was illustrated by simulation and application on a doxorubicin growth inhibition screen. The simulations show that under the proposed mathematical model the suggested statistical workflow results in unbiased estimates of the time independent summary statistics. Variance estimates of the novel summary statistics are used to conclude that the doxorubicin screen covers a significant diverse range of responses ensuring it is useful for biological

Virtual knotting in proteins and other open curves

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Alexander, Keith; Taylor, Alexander; Dennis, Mark

Long filaments naturally knot, from string to long-chain molecules. Knotting in a filament affects its properties, and may be very stable or disappear under slight manipulation. Knotting has been identified in protein backbones for which these mechanical constraints are of fundamental importance to their function, although they are open curves in which knots are not mathematically well defined; knotting can only be identified by closing the ends of the chain. We introduce a new method for resolving knotting in open curves using virtual knots, a wider class of topological objects that do not use a classical closure, capturing the topological ambiguity of open curves. Having analysed all proteins in the Protein Data Bank by this new scheme, we recover and extend previous knotting results, and identify topological interest in some new cases. The statistics of virtual knots in proteins are compared with those of Hamiltonian subchains on cubic lattices, identifying a regime of open curves in which the virtual knotting description is likely to be important. This work was supported by the Leverhulme Trust Programme Grant ``Scientific Properties of Complex Knots'' and the EPSRC.

Curve fitting methods for solar radiation data modeling

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Karim, Samsul Ariffin Abdul, E-mail: samsul-ariffin@petronas.com.my, E-mail: balbir@petronas.com.my; Singh, Balbir Singh Mahinder, E-mail: samsul-ariffin@petronas.com.my, E-mail: balbir@petronas.com.my [Department of Fundamental and Applied Sciences, Faculty of Sciences and Information Technology, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak Darul Ridzuan (Malaysia)

2014-10-24

This paper studies the use of several type of curve fitting method to smooth the global solar radiation data. After the data have been fitted by using curve fitting method, the mathematical model of global solar radiation will be developed. The error measurement was calculated by using goodness-fit statistics such as root mean square error (RMSE) and the value of R{sup 2}. The best fitting methods will be used as a starting point for the construction of mathematical modeling of solar radiation received in Universiti Teknologi PETRONAS (UTP) Malaysia. Numerical results indicated that Gaussian fitting and sine fitting (both with two terms) gives better results as compare with the other fitting methods.

Curve fitting methods for solar radiation data modeling

Science.gov (United States)

Karim, Samsul Ariffin Abdul; Singh, Balbir Singh Mahinder

2014-10-01

This paper studies the use of several type of curve fitting method to smooth the global solar radiation data. After the data have been fitted by using curve fitting method, the mathematical model of global solar radiation will be developed. The error measurement was calculated by using goodness-fit statistics such as root mean square error (RMSE) and the value of R2. The best fitting methods will be used as a starting point for the construction of mathematical modeling of solar radiation received in Universiti Teknologi PETRONAS (UTP) Malaysia. Numerical results indicated that Gaussian fitting and sine fitting (both with two terms) gives better results as compare with the other fitting methods.

Curve fitting methods for solar radiation data modeling

International Nuclear Information System (INIS)

Karim, Samsul Ariffin Abdul; Singh, Balbir Singh Mahinder

2014-01-01

This paper studies the use of several type of curve fitting method to smooth the global solar radiation data. After the data have been fitted by using curve fitting method, the mathematical model of global solar radiation will be developed. The error measurement was calculated by using goodness-fit statistics such as root mean square error (RMSE) and the value of R 2 . The best fitting methods will be used as a starting point for the construction of mathematical modeling of solar radiation received in Universiti Teknologi PETRONAS (UTP) Malaysia. Numerical results indicated that Gaussian fitting and sine fitting (both with two terms) gives better results as compare with the other fitting methods

Mediation Analysis in a Latent Growth Curve Modeling Framework

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von Soest, Tilmann; Hagtvet, Knut A.

2011-01-01

This article presents several longitudinal mediation models in the framework of latent growth curve modeling and provides a detailed account of how such models can be constructed. Logical and statistical challenges that might arise when such analyses are conducted are also discussed. Specifically, we discuss how the initial status (intercept) and…

A study of the relationship between the study process, motivation resources, and motivation problems of nursing students in different educational systems.

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Yardimci, Figen; Bektaş, Murat; Özkütük, Nilay; Muslu, Gonca Karayağız; Gerçeker, Gülçin Özalp; Başbakkal, Zümrüt

2017-01-01

The study process is related to students' learning approaches and styles. Motivation resources and problems determine students' internal, external, and negative motivation. Analyzing the study process and motivation of students yields important indications about the nature of educational systems in higher education. This study aims to analyze the relationship between the study process, and motivation resources and problems with regard to nursing students in different educational systems in Turkey and to reveal their effects according to a set of variables. This is a descriptive, cross-sectional and correlational study. Traditional, integrated and problem-based learning (PBL) educational programs for nurses involving students from three nursing schools in Turkey. Nursing students (n=330). The data were collected using the Study Process Questionnaire (R-SPQ-2F) and the Motivation Resources and Problems (MRP) Scale. A statistically significant difference was found between the scores on the study process scale, and motivation resources and problems scale among the educational systems. This study determined that the mean scores of students in the PBL system on learning approaches, intrinsic motivation and negative motivation were higher. A positive significant correlation was found between the scales. The study process, and motivation resources and problems were found to be affected by the educational system. This study determined that the PBL educational system more effectively increases students' intrinsic motivation and helps them to acquire learning skills. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nursing Students' Intrinsic Motivation and Performance on the Licensure Examination.

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Hackney, Michele G

Unsuccessful attempts at licensure adversely affect graduates, prelicensure nursing education programs, health care agencies, and ultimately, patient safety. The purpose of this quantitative, correlational study was to investigate the relationship between nursing students' intrinsic motivation and performance on the licensure examination. Nursing students responded to 12 questions related to reasons for learning as indicators of motivation type. Results indicated no statistically significant correlations between variables.

Psychosocial Predictors for Cancer Prevention Behaviors in Workplace Using Protection Motivation Theory.

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Zare Sakhvidi, Mohammad Javad; Zare, Maryam; Mostaghaci, Mehrdad; Mehrparvar, Amir Houshang; Morowatisharifabad, Mohammad Ali; Naghshineh, Elham

2015-01-01

Backgrounds. The aim of this study was to describe the preventive behaviors of industrial workers and factors influencing occupational cancer prevention behaviors using protection motivation theory. Methods. A self-administered questionnaire was completed by 161 petrochemical workers in Iran in 2014 which consisted of three sections: background information, protection motivation theory measures, and occupational cancers preventive behaviors. Results. A statistically significant positive correlation was found between PM and self-efficacy, response efficacy, and the cancer preventive behaviors. Meanwhile, statistically significant negative correlations were found between PM, cost, and reward. Conclusions. Among available PMT constructs, only self-efficacy and cost were significant predictors of preventive behaviors. Protection motivation model based health promotion interventions with focus on self-efficacy and cost would be desirable in the case of occupational cancers prevention.

Psychosocial Predictors for Cancer Prevention Behaviors in Workplace Using Protection Motivation Theory

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Mohammad Javad Zare Sakhvidi

2015-01-01

Full Text Available Backgrounds. The aim of this study was to describe the preventive behaviors of industrial workers and factors influencing occupational cancer prevention behaviors using protection motivation theory. Methods. A self-administered questionnaire was completed by 161 petrochemical workers in Iran in 2014 which consisted of three sections: background information, protection motivation theory measures, and occupational cancers preventive behaviors. Results. A statistically significant positive correlation was found between PM and self-efficacy, response efficacy, and the cancer preventive behaviors. Meanwhile, statistically significant negative correlations were found between PM, cost, and reward. Conclusions. Among available PMT constructs, only self-efficacy and cost were significant predictors of preventive behaviors. Protection motivation model based health promotion interventions with focus on self-efficacy and cost would be desirable in the case of occupational cancers prevention.

Predicting long-term growth in students' mathematics achievement: the unique contributions of motivation and cognitive strategies.

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Murayama, Kou; Pekrun, Reinhard; Lichtenfeld, Stephanie; Vom Hofe, Rudolf

2013-01-01

This research examined how motivation (perceived control, intrinsic motivation, and extrinsic motivation), cognitive learning strategies (deep and surface strategies), and intelligence jointly predict long-term growth in students' mathematics achievement over 5 years. Using longitudinal data from six annual waves (Grades 5 through 10; Mage  = 11.7 years at baseline; N = 3,530), latent growth curve modeling was employed to analyze growth in achievement. Results showed that the initial level of achievement was strongly related to intelligence, with motivation and cognitive strategies explaining additional variance. In contrast, intelligence had no relation with the growth of achievement over years, whereas motivation and learning strategies were predictors of growth. These findings highlight the importance of motivation and learning strategies in facilitating adolescents' development of mathematical competencies. © 2012 The Authors. Child Development © 2012 Society for Research in Child Development, Inc.

Quantifying and Reducing Curve-Fitting Uncertainty in Isc: Preprint

Energy Technology Data Exchange (ETDEWEB)

Campanelli, Mark; Duck, Benjamin; Emery, Keith

2015-09-28

Current-voltage (I-V) curve measurements of photovoltaic (PV) devices are used to determine performance parameters and to establish traceable calibration chains. Measurement standards specify localized curve fitting methods, e.g., straight-line interpolation/extrapolation of the I-V curve points near short-circuit current, Isc. By considering such fits as statistical linear regressions, uncertainties in the performance parameters are readily quantified. However, the legitimacy of such a computed uncertainty requires that the model be a valid (local) representation of the I-V curve and that the noise be sufficiently well characterized. Using more data points often has the advantage of lowering the uncertainty. However, more data points can make the uncertainty in the fit arbitrarily small, and this fit uncertainty misses the dominant residual uncertainty due to so-called model discrepancy. Using objective Bayesian linear regression for straight-line fits for Isc, we investigate an evidence-based method to automatically choose data windows of I-V points with reduced model discrepancy. We also investigate noise effects. Uncertainties, aligned with the Guide to the Expression of Uncertainty in Measurement (GUM), are quantified throughout.

Application of Parallel Hierarchical Matrices in Spatial Statistics and Parameter Identification

KAUST Repository

Litvinenko, Alexander

2018-04-20

Parallel H-matrices in spatial statistics 1. Motivation: improve statistical model 2. Tools: Hierarchical matrices [Hackbusch 1999] 3. Matern covariance function and joint Gaussian likelihood 4. Identification of unknown parameters via maximizing Gaussian log-likelihood 5. Implementation with HLIBPro

Measurement of self-evaluative motives: a shopping scenario.

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Wajda, Theresa A; Kolbe, Richard; Hu, Michael Y; Cui, Annie Peng

2008-08-01

To develop measures of consumers' self-evaluative motives of Self-verification, Self-enhancement, and Self-improvement within the context of a mall shopping environment, an initial set of 49 items was generated by conducting three focus-group sessions. These items were subsequently converted into shopping-dependent motive statements. 250 undergraduate college students responded on a 7-point scale to each statement as these related to the acquisition of recent personal shopping goods. An exploratory factor analysis yielded five factors, accounting for 57.7% of the variance, three of which corresponded to the Self-verification motive (five items), Self-enhancement motive (three items), and Self-improvement motive (six items). These 14 items, along with 9 reconstructed items, yielded 23 items retained and subjected to additional testing. In a final round of data collection, 169 college students provided data for exploratory factor analysis. 11 items were used in confirmatory factor analysis. Analysis indicated that the 11-item scale adequately captured measures of the three self-evaluative motives. However, further data reduction produced a 9-item scale with marked improvement in statistical fit over the 11-item scale.

Fluctuations in work motivation: tasks do not matter!

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Navarro, Jose; Curioso, Fernando; Gomes, Duarte; Arrieta, Carlos; Cortes, Mauricio

2013-01-01

Previous studies have shown that work motivation fluctuates considerably and in a nonlinear way over time. In the present research, we are interested in studying if the task at hand does or does not influence the presence of these fluctuations. We gathered daily registers from 69 workers during 21 consecutive working days (7036 registers) of task developed and levels of motivation, self-efficacy beliefs and instrumentalities perception. These registers were then categorized into a list of labor activities in main tasks and subtasks by means of three judges with a high level of agreement (97.47% for tasks, and 98.64% for subtasks). Taking the MSSD statistic (mean squared successive difference) of the average of motivation, self-efficacy and instrumentality, and using hierarchical regression analysis we have found that tasks (beta = .03; p = .188) and subtasks (beta = .10; p = .268) do not affect the presence of fluctuations in motivation. These results reveal instability in work motivation independently from the tasks and subtasks that the workers do. We proceed to find that fluctuations in work motivation show a fractal structure across the different tasks we do in a working day. Implications of these results to motivational theory will be discussed as well as possible explanations (e.g. the influence of affect in work motivation) and directions for future research are provided.

How do rewards and management styles influence the motivation to share knowledge?

OpenAIRE

Harder, Mie

2008-01-01

How to motivate knowledge sharing is of crucial importance to many companies. This paper analyzes individual knowledge sharing behavior in a self-determination theory (SDT) perspective. The primary aim is to explore what type of motivation predicts knowledge sharing behavior and how this type of motivation is affected by reward structures and management styles in organizations. The paper builds on survey and interview data from a pilot case study and provides statistical evidence of a strong ...

Parameters leading to a successful radiographic outcome following surgical treatment for Lenke 2 curves.

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Koller, Heiko; Meier, Oliver; McClung, Anna; Hitzl, Wolfgang; Mayer, Michael; Sucato, Daniel

2015-07-01

In Lenke 2 curves, there are conflicting data when to include the PTC into the fusion. Studies focusing on Lenke 2 curves are scant. The number of patients with significant postoperative shoulder height difference (SHD) or trunk shift (TS) is as high as 30 % indicating further research. Therefore, the purpose of the current study was to improve understanding of curve resolution and shoulder balance following surgical correction of Lenke 2 curves as well as the identification of radiographic parameters predicting postoperative curve resolution, shoulder and trunk balance in perspective of inclusion/exclusion of the proximal thoracic curve (PTC). This is a retrospective study of a 158 Lenke 2 curves. Serial radiographs were analyzed for the main thoracic curve (MTC), PTC, and lumbar curve (LC), SHD, clavicle angle (CA), T-1 tilt, deviation of the central sacral vertical line (CSVL) off the C7 plumb line.Patients were stratified whether the PTC was included in the fusion (+PTC group, n = 60) or not (-PTC group, n = 98). Intergroup results were studied. Compensatory mechanisms for SHD were studied in detail. Adding-on distally was defined as an increase of the lowest instrumented vertebra adjacent disc angle (LIVDA) >3°. Stepwise regression analyses were performed to establish predictive radiographic parameters. At follow-up averaging 24 months significant differences between the +PTC and -PTC group existed for the PTC (24° vs 28°, p 5° (27 vs 53 %, p 2 cm) was 9 (6 %): 7 in the -PTC vs 2 in the +PTC group (p = .03). Utilization of compensatory mechanisms (99 vs 83 %, p Statistics showed postoperative SHD improvement in both the +PTC and -PTC groups. There were no significant differences regarding SHD, CA and T1-Tilt between groups. However, only in the -PTC group, a significant change between postoperative and follow-up SHD existed (p = .02). Statistics identified a preoperative 'left shoulder up' (p statistical model only for the -PTC group showed 9 parameters

Is the intrinsic motivation of career choice important for the later professional development of teachers?

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Marušić Milica

2014-01-01

Full Text Available The nature of teachers’ professional choice motivation has been proved important for the later professional development. The goal of the present research was to determine the role of the intrinsic motivation in the participants’ decision to become teachers, as well as to establish the importance of intrinsic motivation for their later professional development. We have conducted a quantitative research, within a sample consisted of 118 secondary school teachers, by application of survey method (instrument– questionnaire in the form of Likert-type scale. Statistical analysis has consisted of: hierarchical cluster analysis, descriptive statistics, factor analysis and rank correlation. It was established that the intrinsic motivation takes precedence over the extrinsic motivation in the process of professional choice determination. We have also confirmed the hypothesis claiming that the level of intrinsic motivation correlates with the indicators of professional behavior. Besides, the level of intrinsic motivation is better predictor of the enthusiasm and growth then of the career frustration (Fessler, 1995. Our results are in favor of the teacher education system, where the candidates apply and prepare for the teacher profession from the beginning of the initial education.

Statistical analysis of the ASME KIc database

International Nuclear Information System (INIS)

Sokolov, M.A.

1998-01-01

The American Society of Mechanical Engineers (ASME) K Ic curve is a function of test temperature (T) normalized to a reference nil-ductility temperature, RT NDT , namely, T-RT NDT . It was constructed as the lower boundary to the available K Ic database. Being a lower bound to the unique but limited database, the ASME K Ic curve concept does not discuss probability matters. However, a continuing evolution of fracture mechanics advances has led to employment of the Weibull distribution function to model the scatter of fracture toughness values in the transition range. The Weibull statistic/master curve approach was applied to analyze the current ASME K Ic database. It is shown that the Weibull distribution function models the scatter in K Ic data from different materials very well, while the temperature dependence is described by the master curve. Probabilistic-based tolerance-bound curves are suggested to describe lower-bound K Ic values

LINS Curve in Romanian Economy

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Emilian Dobrescu

2016-02-01

Full Text Available The paper presents theoretical considerations and empirical evidence to test the validity of the Laffer in Narrower Sense (LINS curve as a parabola with a maximum. Attention is focused on the so-called legal-effective tax gap (letg. The econometric application is based on statistical data (1990-2013 for Romania as an emerging European economy. Three cointegrating regressions (fully modified least squares, canonical cointegrating regression and dynamic least squares and three algorithms, which are based on instrumental variables (two-stage least squares, generalized method of moments, and limited information maximum likelihood, are involved.

Sensitivity of Fit Indices to Misspecification in Growth Curve Models

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Wu, Wei; West, Stephen G.

2010-01-01

This study investigated the sensitivity of fit indices to model misspecification in within-individual covariance structure, between-individual covariance structure, and marginal mean structure in growth curve models. Five commonly used fit indices were examined, including the likelihood ratio test statistic, root mean square error of…

POSSIBLE RECESSION CURVE APPLICATIONS FOR RETENTION EVALUATION

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Daniel Liberacki

2015-11-01

Full Text Available The objective of the article was to present possible applications of recession flow curve in a small lowland watershed retention discharge size evaluation. The examined woodland micro catchment area of 0.52 sq km is located in Puszcza Zielonka in central Wielkopolska. The Hutka catchment is typically woody with high retention abilities. The catchment of the Hutka watercourse is forested in 89%, the other 11% is covered by swamps and wasteland. The predominant sites are fresh mixed coniferous forest (BMśw, fresh coniferous forest (Bśw and alder carr forest (Ol. Landscape in catchment is characterized by a large number of interior depressions, filled partly with rainwater or peatbogs, with poorly developed natural drainage. The watercourses do not exceed 1 km in length, the mean width is approx. 0.5 m, while mean depth ranges from 0.2 to 0.3 m. During hydrological research conducted in 1997/1998–1999/2000, 35 major (characteristic raised water stages were observed in Hutka after substantial precipitation. The recession curve dating from 18–24 September 2000 has the α and n rates nearest to average. Comparing the model curve and the curve created by observing watercourse flow, one can notice their resemblance and that they have similar ordinate values as well as shape. In the case of other recession curves, the maximum differences of ordinate values are also about 0.1–0.2 l/s/km2. The measuured α and n rates do not reveal any regularities. There are no significant statistical Horton model parameter (for recession flow curves dependencies between α and n and e.g. initial flows (Qo or the whole period of high water waves (Qp. Consequently, calculated relation between these parameters is only an approximation for the general evaluation of the retention discharge in the catchment area towards retention with flow function.

Intrinsic motivation and amotivation in first episode and prolonged psychosis.

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Luther, Lauren; Lysaker, Paul H; Firmin, Ruth L; Breier, Alan; Vohs, Jenifer L

2015-12-01

The deleterious functional implications of motivation deficits in psychosis have generated interest in examining dimensions of the construct. However, there remains a paucity of data regarding whether dimensions of motivation differ over the course of psychosis. Therefore, this study examined two motivation dimensions, trait-like intrinsic motivation, and the negative symptom of amotivation, and tested the impact of illness phase on the 1) levels of these dimensions and 2) relationship between these dimensions. Participants with first episode psychosis (FEP; n=40) and prolonged psychosis (n=66) completed clinician-rated measures of intrinsic motivation and amotivation. Analyses revealed that when controlling for group differences in gender and education, the FEP group had significantly more intrinsic motivation and lower amotivation than the prolonged psychosis group. Moreover, intrinsic motivation was negatively correlated with amotivation in both FEP and prolonged psychosis, but the magnitude of the relationship did not statistically differ between groups. These findings suggest that motivation deficits are more severe later in the course of psychosis and that low intrinsic motivation may be partially independent of amotivation in both first episode and prolonged psychosis. Clinically, these results highlight the importance of targeting motivation in early intervention services. Copyright © 2015 Elsevier B.V. All rights reserved.

TOWARD CHARACTERIZATION OF THE TYPE IIP SUPERNOVA PROGENITOR POPULATION: A STATISTICAL SAMPLE OF LIGHT CURVES FROM Pan-STARRS1

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Sanders, N. E.; Soderberg, A. M.; Chornock, R.; Berger, E.; Challis, P.; Drout, M.; Kirshner, R. P.; Lunnan, R.; Marion, G. H.; Margutti, R.; McKinnon, R.; Milisavljevic, D. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Gezari, S. [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Betancourt, M. [Department of Statistics, University of Warwick, Coventry (United Kingdom); Foley, R. J. [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, IL 61801 (United States); Narayan, G. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Rest, A. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Kankare, E.; Mattila, S. [Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Väisäläntie 20, 21500 Piikkiö (Finland); Smartt, S. J., E-mail: nsanders@cfa.harvard.edu [Astrophysics Research Centre, School of Mathematics and Physics, Queens University, BT7 1NN, Belfast (United Kingdom); and others

2015-02-01

In recent years, wide-field sky surveys providing deep multiband imaging have presented a new path for indirectly characterizing the progenitor populations of core-collapse supernovae (SNe): systematic light-curve studies. We assemble a set of 76 grizy-band Type IIP SN light curves from Pan-STARRS1, obtained over a constant survey program of 4 yr and classified using both spectroscopy and machine-learning-based photometric techniques. We develop and apply a new Bayesian model for the full multiband evolution of each light curve in the sample. We find no evidence of a subpopulation of fast-declining explosions (historically referred to as ''Type IIL'' SNe). However, we identify a highly significant relation between the plateau phase decay rate and peak luminosity among our SNe IIP. These results argue in favor of a single parameter, likely determined by initial stellar mass, predominantly controlling the explosions of red supergiants. This relation could also be applied for SN cosmology, offering a standardizable candle good to an intrinsic scatter of ≲ 0.2 mag. We compare each light curve to physical models from hydrodynamic simulations to estimate progenitor initial masses and other properties of the Pan-STARRS1 Type IIP SN sample. We show that correction of systematic discrepancies between modeled and observed SN IIP light-curve properties and an expanded grid of progenitor properties are needed to enable robust progenitor inferences from multiband light-curve samples of this kind. This work will serve as a pathfinder for photometric studies of core-collapse SNe to be conducted through future wide-field transient searches.

Influence of horizontally curved roadway section characteristics on motorcycle-to-barrier crash frequency.

Science.gov (United States)

Gabauer, Douglas J; Li, Xiaolong

2015-04-01

The purpose of this study was to investigate motorcycle-to-barrier crash frequency on horizontally curved roadway sections in Washington State using police-reported crash data linked with roadway data and augmented with barrier presence information. Data included 4915 horizontal curved roadway sections with 252 of these sections experiencing 329 motorcycle-to-barrier crashes between 2002 and 2011. Negative binomial regression was used to predict motorcycle-to-barrier crash frequency using horizontal curvature and other roadway characteristics. Based on the model results, the strongest predictor of crash frequency was found to be curve radius. This supports a motorcycle-to-barrier crash countermeasure placement criterion based, at the very least, on horizontal curve radius. With respect to the existing horizontal curve criterion of 820 feet or less, curves meeting this criterion were found to increase motorcycle-to-barrier crash frequency rate by a factor of 10 compared to curves not meeting this criterion. Other statistically significant predictors were curve length, traffic volume and the location of adjacent curves. Assuming curves of identical radius, the model results suggest that longer curves, those with higher traffic volume, and those that have no adjacent curved sections within 300 feet of either curve end would likely be better candidates for a motorcycle-to-barrier crash countermeasure. Copyright © 2015 Elsevier Ltd. All rights reserved.

WHAT MOTIVATES CULTURAL TOURISTS? AN ANALYSIS OF BUCHAREST INHABITANTS' MOTIVATION TO VISIT THE CENTRE REGION

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Ravar Anamaria Sidonia

2013-07-01

Full Text Available Cultural tourism is currently one of the main driving forces of the tourist phenomena, accounting for a significant part of the world's tourist flows. Cultural tourism may take many forms, according to the motivation behind tourists' impetus to travel to a certain destination. Cultural heritage and historical sites, dance, music and theatre performances, art galleries, museums and exhibitions, religious and worship sites and ethnic traditions are the main attractions for tourists motivated by knowledge seeking, self-development and the desire to experience other cultures. Although cultural motivations play an important role in the generation of tourist flows towards cultural tourism destinations, a tourism experience is rarely generated as a result of a single motivation. The act of choosing a specific destination and tourism product is influenced by multiple motivations, not only cultural but also connected to relaxation or family. Furthermore, tourism products are rarely homogeneous – a single holiday may include experiences with cultural content as well as leisure time, sports, adventure or entertainment. Thus, culture is not always the main motivation behind cultural tourism and may in fact be less central to the decision to travel than other factors. This is particularly true in the case of destinations which dispose of various cultural assets, but whose natural tourist resources – such as landscape, climate, access to the sea – also makes them attractive for other types of tourism. The aim of this article is to show that in the case of tourist destinations where cultural attractions represent the vast majority of the areas' tourist heritage, cultural motivations remains central to the decision to travel. Furthermore, we will seek to identify the main types of cultural attractions that motivate cultural tourism in Romania by investigating Bucharest inhabitants' perception of the Centre Region, a cultural destination par excellence in

Correlates of motivation to change in pathological gamblers completing cognitive-behavioral group therapy.

Science.gov (United States)

Gómez-Peña, Mónica; Penelo, Eva; Granero, Roser; Fernández-Aranda, Fernando; Alvarez-Moya, Eva; Santamaría, Juan José; Moragas, Laura; Neus Aymamí, Maria; Gunnard, Katarina; Menchón, José M; Jimenez-Murcia, Susana

2012-07-01

The present study analyzes the association between the motivation to change and the cognitive-behavioral group intervention, in terms of dropouts and relapses, in a sample of male pathological gamblers. The specific objectives were as follows: (a) to estimate the predictive value of baseline University of Rhode Island Change Assessment scale (URICA) scores (i.e., at the start of the study) as regards the risk of relapse and dropout during treatment and (b) to assess the incremental predictive ability of URICA scores, as regards the mean change produced in the clinical status of patients between the start and finish of treatment. The relationship between the URICA and the response to treatment was analyzed by means of a pre-post design applied to a sample of 191 patients who were consecutively receiving cognitive-behavioral group therapy. The statistical analysis included logistic regression models and hierarchical multiple linear regression models. The discriminative ability of the models including the four URICA scores regarding the likelihood of relapse and dropout was acceptable (area under the receiver operating haracteristic curve: .73 and .71, respectively). No significant predictive ability was found as regards the differences between baseline and posttreatment scores (changes in R(2) below 5% in the multiple regression models). The availability of useful measures of motivation to change would enable treatment outcomes to be optimized through the application of specific therapeutic interventions. © 2012 Wiley Periodicals, Inc.

Distortion-product otoacoustic emission growth curves in neonates

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Tania Alves Barbosa

2014-12-01

Full Text Available Background: The recording of otoacoustic emissions (OAE enabled us to prove that the cochlea is able not only to receive sounds but also to produce acoustic energy. Through the use of distortion-product otoacoustic emission measurements, the growth of the response was seen according to the intensity of the sound stimulus presented (growth curve. Objective: to determine the thresholds for the emergence of distortion-product otoacoustic emissions (DPOAE on frequencies of 2000 and 4000 Hz with a stimulus varying from 20 to 65dB SPL, and to establish the slope values obtained in the growth curves. Methods: 39 neonates aged 5 to 28 days without risk indicators of hearing loss were studied. The DPOAE growth curves were obtained on the frequencies from 2000 Hz and 4000 Hz with a level of intensity ranging from 20 to 65dB SPL divided into two paradigms (20 to 40dB SPL and 40-65dB SPL. Results: there was a statistically significant difference in the thresholds for the emergence of DPOAE depending on the criteria used. The thresholds were on average higher at 4000 Hz than 2000 Hz and the slope was higher on average at 2000 Hz than 4000 Hz, although not statistically significant in either case. Conclusion: the thresholds were on average 30dB SPL at 2000Hz and 35dB SPL at 4000Hz. The slope values varied between 3 and 4 on average, reaching 15 in some cases.

Statistically based evaluation of toughness properties of components in older nuclear power stations

International Nuclear Information System (INIS)

Aurich, D.; Jaenicke, B.; Veith, H.

1996-01-01

The KTA code 3201.2 contains provisions for the evaluation of K Ic values measured in components, but there are no instructions on how to proceed. According to the present state of the art in science and technology, fracture toughness values K Ic (T) should be evaluated statistically in order to specify the relationship to the loading values K I (T). The 'Master Curve' concept of Wallin yields too flat a curve shape at high temperatures. The statistical evaluation of K Ic values can also be carried out with the KTA-K Ic reference temperature function assuming a normal distribution of the measuring values. The KTA-K Ic reference temperature curve approximately corresponds to a fracture probability of 5 % when the KTA-K Ic reference temperature function is used for the statistical evaluation of the test results. Conclusions for the assessment of the safe distances can be drawn from the steeper shape of the KTA-K Ic reference temperature function in comparison to the 'Master Curve'. (orig.) [de

Does intrinsic motivation enhance motor cortex excitability?

Science.gov (United States)

Radel, Rémi; Pjevac, Dusan; Davranche, Karen; d'Arripe-Longueville, Fabienne; Colson, Serge S; Lapole, Thomas; Gruet, Mathieu

2016-11-01

Intrinsic motivation (IM) is often viewed as a spontaneous tendency for action. Recent behavioral and neuroimaging evidence indicate that IM, in comparison to extrinsic motivation (EM), solicits the motor system. Accordingly, we tested whether IM leads to greater excitability of the motor cortex than EM. To test this hypothesis, we used two different tasks to induce the motivational orientation using either words representing each motivational orientation or pictures previously linked to each motivational orientation through associative learning. Single-pulse transcranial magnetic stimulation over the motor cortex was applied when viewing the stimuli. Electromyographic activity was recorded on the contracted first dorsal interosseous muscle. Two indexes of corticospinal excitability (the amplitude of motor-evoked potential and the length of cortical silent period) were obtained through unbiased automatic detection and analyzed using a mixed model that provided both statistical power and a high level of control over all important individual, task, and stimuli characteristics. Across the two tasks and the two indices of corticospinal excitability, the exposure to IM-related stimuli did not lead to a greater corticospinal excitability than EM-related stimuli or than stimuli with no motivational valence (ps > .20). While these results tend to dismiss the advantage of IM at activating the motor cortex, we suggest alternative hypotheses to explain this lack of effect, which deserves further research. © 2016 Society for Psychophysiological Research.

Statistical evaluation of fracture characteristics of RPV steels in the ductile-brittle transition temperature region

International Nuclear Information System (INIS)

Kang, Sung Sik; Chi, Se Hwan; Hong, Jun Hwa

1998-01-01

The statistical analysis method was applied to the evaluation of fracture toughness in the ductile-brittle transition temperature region. Because cleavage fracture in steel is of a statistical nature, fracture toughness data or values show a similar statistical trend. Using the three-parameter Weibull distribution, a fracture toughness vs. temperature curve (K-curve) was directly generated from a set of fracture toughness data at a selected temperature. Charpy V-notch impact energy was also used to obtain the K-curve by a K IC -CVN (Charpy V-notch energy) correlation. Furthermore, this method was applied to evaluate the neutron irradiation embrittlement of reactor pressure vessel(RPV) steel. Most of the fracture toughness data were within the 95 percent confidence limits. The prediction of a transition temperature shift by statistical analysis was compared with that from the experimental data. (author)

Motivation of medical students: selection by motivation or motivation by selection.

Science.gov (United States)

Wouters, Anouk; Croiset, Gerda; Galindo-Garre, Francisca; Kusurkar, Rashmi A

2016-01-29

Medical schools try to implement selection procedures that will allow them to select the most motivated students for their programs. Though there is a general feeling that selection stimulates student motivation, conclusive evidence for this is lacking. The current study aims to use the perspective of Self-determination Theory (SDT) of motivation as a lens to examine how medical students' motivation differs in relation to different selection procedures. The hypotheses were that 1) selected students report higher strength and autonomous motivation than non-selected students, and 2) recently selected students report higher strength and autonomous motivation than non-selected students and students who were selected longer ago. First- (Y1) and fourth-year (Y4) medical students in the six-year regular programme and first-year students in the four-year graduate entry programme (GE) completed questionnaires measuring motivation strength and type (autonomous-AM, controlled-CM). Scores were compared between students admitted based on selection, lottery or top pre-university GPA (top GPA) using ANCOVAs. Selected students' answers on open-ended questions were analysed using inductive thematic analysis to identify reasons for changes in motivation. The response rate was 61.4 % (n = 357). Selected students (Y1, Y4 and GE) reported a significantly higher strength of motivation than non-selected students (Y1 and Y4 lottery and top GPA) (p motivation as they felt autonomous, competent and that they belonged to a special group. These reported reasons are in alignment with the basic psychological needs described by Self-Determination Theory as important in enhancing autonomous motivation. A comprehensive selection procedure, compared to less demanding admission procedures, does not seem to yield a student population which stands out in terms of autonomous motivation. The current findings indicate that selection might temporarily enhance students' motivation. The mechanism

Explaining Math Achievement: Personality, Motivation, and Trust

Science.gov (United States)

Kilic-Bebek, Ebru

2009-01-01

This study investigated the statistical significance of student trust next to the well-tested constructs of personality and motivation to determine whether trust is a significant predictor of course achievement in college math courses. Participants were 175 students who were taking undergraduate math courses in an urban public university. The…

Nursing students motivation toward their studies – a survey study

Directory of Open Access Journals (Sweden)

Nilsson Kerstin EL

2008-04-01

Full Text Available Abstract Background This study focuses on Swedish nursing students' motivation toward their studies during their three year academic studies. Earlier studies show the importance of motivation for study commitment and result. The aim was to analyze nursing students' estimation of their degree of motivation during different semester during their education and to identify reasons for the degree of motivation. Methods A questionnaire asking for scoring motivation and what influenced the degree of motivation was distributed to students enrolled in a nursing programme. 315 students who studied at different semesters participated. Analyzes were made by statistical calculation and content analysis. Results The mean motivation score over all semesters was 6.3 (ranked between 0–10 and differed significantly during the semesters with a tendency to lower score during the 5th semester. Students (73/315 with motivation score 6 reported positive opinions to becoming a nurse (125/234, organization of the programme and attitude to the studies. The mean score value for the motivation ranking differed significantly between male (5.8 and female (6.8 students. Conclusion Conclusions to be drawn are that nursing students mainly grade their motivation positive distributed different throughout their entire education. The main motivation factor was becoming a nurse. This study result highlights the need of understanding the students' situation and their need of tutorial support.

Obstacles to and motivation for successful breast-feeding

Directory of Open Access Journals (Sweden)

A-M Bergh

1993-03-01

Full Text Available This study determined obstetric physiotherapists' perceptions about major obstacles to and methods of motivation for successful breast-feeding by means of the Friedman non-parametric procedure for the two-way analysis of variance. Three categories of obstacles were identified: maternal obstacles, health professionals and society. Maternal obstacles mentioned most were insufficient motivation (25% and knowledge (24%, anxiety (14%, fatigue (14%, and employment (14%. Obstacles related to health professionals included tack of support for mothers (20%, inappropriate lactation management (19%, lack of knowledge (15%, negative attitudes (5% and staff shortages (5%. With regard to society, lack of support (27% and life-styles (29% were identified as significant obstacles. The two most significantly important methods of motivation were information and education (53% and contact with other breast-feeders (27%. It is concluded that breast-feeding education efforts can be improved by identifying obstacles to breast-feeding and methods of motivation and that the Friedman test may be a statistical procedure to consider for determining priorities.

Evidence against the continuum structure underlying motivation measures derived from self-determination theory.

Science.gov (United States)

Chemolli, Emanuela; Gagné, Marylène

2014-06-01

Self-determination theory (SDT) proposes a multidimensional conceptualization of motivation in which the different regulations are said to fall along a continuum of self-determination. The continuum has been used as a basis for using a relative autonomy index as a means to create motivational scores. Rasch analysis was used to verify the continuum structure of the Multidimensional Work Motivation Scale and of the Academic Motivation Scale. We discuss the concept of continuum against SDT's conceptualization of motivation and argue against the use of the relative autonomy index on the grounds that evidence for a continuum structure underlying the regulations is weak and because the index is statistically problematic. We suggest exploiting the full richness of SDT's multidimensional conceptualization of motivation through the use of alternative scoring methods when investigating motivational dynamics across life domains.

[Motivational orientation and depressive symptoms in the elderly].

Science.gov (United States)

Altintas, E; Guerrien, A

2009-04-01

This article is focused on motivation and depression in later life. For about 20 years, research on the motivation of elders has underlined the importance of the cognitive evaluation of life contexts, notably in terms of self-determination. This cognitive evaluation determines the motivational orientation for daily activities (notably the levels of intrinsic and extrinsic motivation). The purpose of this research was specifically to study the relationships between the existence of four types of motivation (intrinsic, self-determined extrinsic, nonself-determined extrinsic and amotivation) and the consequences for adaptation and well-being. The study, therefore, focused on the possible links between motivation and geriatric-depression level and explored the nature of this link. Forty persons aged 60 or over (31 women: 80.48+/-9.24; nine men: 80.56+/-9.48) who live in nursing homes (20 elderly) or in their own homes (20 elderly) were enrolled. Elderly persons were assessed with specific and standardized tools: the Elderly Motivation Scale (EMS, in the French version: EMPA) and the Geriatric Depression Scale (GDS). For the statistical analyses of the results, correlations and Mann-Whitney test were used. We found that in elderly people, the motivational styles (the four types of motivation) can be reliably measured and are related to geriatric depression. First, significant positive links were noticed between intrinsic motivation and depression scores and between self-determined extrinsic motivation and depression scores. Conversely, significant negative links were noticed between nonself-determined extrinsic motivation and depression scores and between amotivation and depression scores. The most self-determined elders presented low-depression levels, whereas the more nonself-determined elders showed high-depression levels. Moreover, motivational styles significantly differed in the two groups (depressive or not depressive). The most depressive elders showed

Planar-channeling spatial density under statistical equilibrium

International Nuclear Information System (INIS)

Ellison, J.A.; Picraux, S.T.

1978-01-01

The phase-space density for planar channeled particles has been derived for the continuum model under statistical equilibrium. This is used to obtain the particle spatial probability density as a function of incident angle. The spatial density is shown to depend on only two parameters, a normalized incident angle and a normalized planar spacing. This normalization is used to obtain, by numerical calculation, a set of universal curves for the spatial density and also for the channeled-particle wavelength as a function of amplitude. Using these universal curves, the statistical-equilibrium spatial density and the channeled-particle wavelength can be easily obtained for any case for which the continuum model can be applied. Also, a new one-parameter analytic approximation to the spatial density is developed. This parabolic approximation is shown to give excellent agreement with the exact calculations

Growth curve registration for evaluating salinity tolerance in barley

KAUST Repository

Meng, Rui

2017-03-23

Background: Smarthouses capable of non-destructive, high-throughput plant phenotyping collect large amounts of data that can be used to understand plant growth and productivity in extreme environments. The challenge is to apply the statistical tool that best analyzes the data to study plant traits, such as salinity tolerance, or plant-growth-related traits. Results: We derive family-wise salinity sensitivity (FSS) growth curves and use registration techniques to summarize growth patterns of HEB-25 barley families and the commercial variety, Navigator. We account for the spatial variation in smarthouse microclimates and in temporal variation across phenotyping runs using a functional ANOVA model to derive corrected FSS curves. From FSS, we derive corrected values for family-wise salinity tolerance, which are strongly negatively correlated with Na but not significantly with K, indicating that Na content is an important factor affecting salinity tolerance in these families, at least for plants of this age and grown in these conditions. Conclusions: Our family-wise methodology is suitable for analyzing the growth curves of a large number of plants from multiple families. The corrected curves accurately account for the spatial and temporal variations among plants that are inherent to high-throughput experiments.

Growth curve registration for evaluating salinity tolerance in barley

KAUST Repository

Meng, Rui; Saade, Stephanie; Kurtek, Sebastian; Berger, Bettina; Brien, Chris; Pillen, Klaus; Tester, Mark A.; Sun, Ying

2017-01-01

Background: Smarthouses capable of non-destructive, high-throughput plant phenotyping collect large amounts of data that can be used to understand plant growth and productivity in extreme environments. The challenge is to apply the statistical tool that best analyzes the data to study plant traits, such as salinity tolerance, or plant-growth-related traits. Results: We derive family-wise salinity sensitivity (FSS) growth curves and use registration techniques to summarize growth patterns of HEB-25 barley families and the commercial variety, Navigator. We account for the spatial variation in smarthouse microclimates and in temporal variation across phenotyping runs using a functional ANOVA model to derive corrected FSS curves. From FSS, we derive corrected values for family-wise salinity tolerance, which are strongly negatively correlated with Na but not significantly with K, indicating that Na content is an important factor affecting salinity tolerance in these families, at least for plants of this age and grown in these conditions. Conclusions: Our family-wise methodology is suitable for analyzing the growth curves of a large number of plants from multiple families. The corrected curves accurately account for the spatial and temporal variations among plants that are inherent to high-throughput experiments.

Students' Motivation toward Computer-Based Language Learning

Science.gov (United States)

Genc, Gulten; Aydin, Selami

2011-01-01

The present article examined some factors affecting the motivation level of the preparatory school students in using a web-based computer-assisted language-learning course. The sample group of the study consisted of 126 English-as-a-foreign-language learners at a preparatory school of a state university. After performing statistical analyses…

CFAssay: statistical analysis of the colony formation assay

International Nuclear Information System (INIS)

Braselmann, Herbert; Michna, Agata; Heß, Julia; Unger, Kristian

2015-01-01

Colony formation assay is the gold standard to determine cell reproductive death after treatment with ionizing radiation, applied for different cell lines or in combination with other treatment modalities. Associated linear-quadratic cell survival curves can be calculated with different methods. For easy code exchange and methodological standardisation among collaborating laboratories a software package CFAssay for R (R Core Team, R: A Language and Environment for Statistical Computing, 2014) was established to perform thorough statistical analysis of linear-quadratic cell survival curves after treatment with ionizing radiation and of two-way designs of experiments with chemical treatments only. CFAssay offers maximum likelihood and related methods by default and the least squares or weighted least squares method can be optionally chosen. A test for comparision of cell survival curves and an ANOVA test for experimental two-way designs are provided. For the two presented examples estimated parameters do not differ much between maximum-likelihood and least squares. However the dispersion parameter of the quasi-likelihood method is much more sensitive for statistical variation in the data than the multiple R 2 coefficient of determination from the least squares method. The dispersion parameter for goodness of fit and different plot functions in CFAssay help to evaluate experimental data quality. As open source software interlaboratory code sharing between users is facilitated

DETERMINISTIC COMPONENTS IN THE LIGHT CURVE AMPLITUDE OF Y OPH

International Nuclear Information System (INIS)

Pop, Alexandru; Turcu, Vlad; Vamos, Calin

2010-01-01

About two decades after the discovery of the amplitude decline of the light curve of the classical Cepheid Y Oph, its study is resumed using an increased amount of homogenized data and an extended time base. In our approach, the investigation of different time series concerning the light curve amplitude of Y Oph is not only the reason for the present study, but also a stimulus for developing a coherent methodology for studying long- and short-term variability phenomena in variable stars, taking into account the details of concrete observing conditions: amount of data, data sampling, time base, and individual errors of observational data. The statistical significance of this decreasing trend was estimated by assuming its linearity. We approached the decision-making process by formulating adequate null and alternative hypotheses, and testing the value of the regression line slope for different data sets via Monte Carlo simulations. A variability analysis, through various methods, of the original data and of the residuals obtained after removing the linear trend was performed. We also proposed a new statistical test, based on amplitude spectrum analysis and Monte Carlo simulations, intended to evaluate how detectible is a given (linear) trend in well-defined observing conditions: the trend detection probability. The main conclusion of our study on Y Oph is that, even if the false alarm probability is low enough to consider the decreasing trend to be statistically significant, the available data do not allow us to obtain a reasonably powerful test. We are able to confirm the light curve amplitude decline, and the order of magnitude of its slope with a better statistical substantiation. According to the obtained values of the trend detection probability, it seems that the trend we are dealing with is marked by a low detectibility. Our attempt to find signs of possible variability phenomena at shorter timescales ended by emphasizing the relative constancy of our data

PMAnalyzer: a new web interface for bacterial growth curve analysis.

Science.gov (United States)

Cuevas, Daniel A; Edwards, Robert A

2017-06-15

Bacterial growth curves are essential representations for characterizing bacteria metabolism within a variety of media compositions. Using high-throughput, spectrophotometers capable of processing tens of 96-well plates, quantitative phenotypic information can be easily integrated into the current data structures that describe a bacterial organism. The PMAnalyzer pipeline performs a growth curve analysis to parameterize the unique features occurring within microtiter wells containing specific growth media sources. We have expanded the pipeline capabilities and provide a user-friendly, online implementation of this automated pipeline. PMAnalyzer version 2.0 provides fast automatic growth curve parameter analysis, growth identification and high resolution figures of sample-replicate growth curves and several statistical analyses. PMAnalyzer v2.0 can be found at https://edwards.sdsu.edu/pmanalyzer/ . Source code for the pipeline can be found on GitHub at https://github.com/dacuevas/PMAnalyzer . Source code for the online implementation can be found on GitHub at https://github.com/dacuevas/PMAnalyzerWeb . dcuevas08@gmail.com. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press.

Motivational profiles of slovenian high school students and their academic performance outcomes.

Science.gov (United States)

Vrtačnik, Margareta; Juriševič, Mojca; Savec, Vesna Ferk

2010-09-01

Self-determination theory defines motivation as a multidimensional concept, with autonomous and controlled motivation as central factors of broader distinctions. Previous research has proven that academic achievements are positively correlated with autonomous motivation. Students from 10 Slovenian grammar schools were involved in empirical study, in which a cluster analysis revealed two motivational profiles: a low quantity motivation group (low controlled and autonomous motivation) and a good quality motivation group (high autonomous and low or average controlled motivation). Statistically significant differences between the two identified motivational profiles were found for students' general as well as chemistry performance in three grades of schooling. Furthermore, a good quality motivation group is also more in favour of autonomy-supportive teaching methods used in chemistry classes. Examination of students' opinions about important chemistry topics, and on the other hand, unimportant ones, and not connected with life, reveals that the basic reason for distinction might lie in the chemistry teacher's approach used while presenting these topics. Some chemistry teachers are not using an autonomy-supportive way of teaching which would contribute to better teaching outcomes; therefore a need for further research on Slovenian chemistry teachers' motivation and their teaching approaches was recognized.

A Numerical Framework for Sobolev Metrics on the Space of Curves

DEFF Research Database (Denmark)

Bauer, Martin; Bruveris, Martins; Harms, Philipp

2017-01-01

Statistical shape analysis can be done in a Riemannian framework by endowing the set of shapes with a Riemannian metric. Sobolev metrics of order two and higher on shape spaces of parametrized or unparametrized curves have several desirable properties not present in lower order metrics...

A standard curve based method for relative real time PCR data processing

Directory of Open Access Journals (Sweden)

Krause Andreas

2005-03-01

Full Text Available Abstract Background Currently real time PCR is the most precise method by which to measure gene expression. The method generates a large amount of raw numerical data and processing may notably influence final results. The data processing is based either on standard curves or on PCR efficiency assessment. At the moment, the PCR efficiency approach is preferred in relative PCR whilst the standard curve is often used for absolute PCR. However, there are no barriers to employ standard curves for relative PCR. This article provides an implementation of the standard curve method and discusses its advantages and limitations in relative real time PCR. Results We designed a procedure for data processing in relative real time PCR. The procedure completely avoids PCR efficiency assessment, minimizes operator involvement and provides a statistical assessment of intra-assay variation. The procedure includes the following steps. (I Noise is filtered from raw fluorescence readings by smoothing, baseline subtraction and amplitude normalization. (II The optimal threshold is selected automatically from regression parameters of the standard curve. (III Crossing points (CPs are derived directly from coordinates of points where the threshold line crosses fluorescence plots obtained after the noise filtering. (IV The means and their variances are calculated for CPs in PCR replicas. (V The final results are derived from the CPs' means. The CPs' variances are traced to results by the law of error propagation. A detailed description and analysis of this data processing is provided. The limitations associated with the use of parametric statistical methods and amplitude normalization are specifically analyzed and found fit to the routine laboratory practice. Different options are discussed for aggregation of data obtained from multiple reference genes. Conclusion A standard curve based procedure for PCR data processing has been compiled and validated. It illustrates that

Psychosocial Predictors for Cancer Prevention Behaviors in Workplace Using Protection Motivation Theory

OpenAIRE

Zare Sakhvidi, Mohammad Javad; Zare, Maryam; Mostaghaci, Mehrdad; Mehrparvar, Amir Houshang; Morowatisharifabad, Mohammad Ali; Naghshineh, Elham

2015-01-01

Backgrounds. The aim of this study was to describe the preventive behaviors of industrial workers and factors influencing occupational cancer prevention behaviors using protection motivation theory. Methods. A self-administered questionnaire was completed by 161 petrochemical workers in Iran in 2014 which consisted of three sections: background information, protection motivation theory measures, and occupational cancers preventive behaviors. Results. A statistically significant positive corre...

Exercise motives in a sample of Brazilian university students

Directory of Open Access Journals (Sweden)

Dartagnan Pinto Guedes

2013-09-01

Full Text Available The present study aimed to identify the exercise motives according to selected socio-demographic indicators in university students. The sample was comprised of 2,380 individuals (1,213 men and 1,167 women aged between 18 and 35 years. The exercise motives were identified with the Portuguese-translated version of the Exercise Motivations Inventory (EMI-2. University students gave significantly greater importance to exercise for reasons identified as Disease Prevention. Factors that are less relevant in statistical language were identified in a context of motivation associated with Social Recognition and Competition. Sex, age, family economic class, experience with exercise and body weight had a significant effect on the level of importance of exercise among university students. In conclusion, the results found can contribute to the development of physical activity promotion programs and a possible reduction in the number of dropouts among university students.

An Exploration of Sources of Foreign Language Teacher Motivation in Iran

Directory of Open Access Journals (Sweden)

Seyyed Mohammad Alavi

2011-11-01

Full Text Available This study aimed to investigate sources of motivation of English language teachers in Iranian public and private language schools. To this end, a Language Teacher Motivation Source (LTMS questionnaire was developed on the basis of the related literature. The LTMS examined four sources of motivation, i. e., extrinsic (economic, social, emotional, educational, intrinsic, altruistic, and subject matter motivation. Having been piloted and validated, the LTMS was administered to 200 male and female EFL teachers who had been classified in terms of their gender, age, marital status, academic degrees, job status, and their years of language teaching experiences. The results of parametric statistical analyses showed a hierarchy of language teacher sources of motivation that were not similar among different groups of language teachers in terms of their teaching experiences and level of education. This study suggests that authorities pay close attention to the sources of language teacher motivation to improve the quality of English language teaching and learning.

Measuring motivation in schizophrenia: Is a general state of motivation necessary for task-specific motivation?

Science.gov (United States)

Choi, Jimmy; Choi, Kee-Hong; Reddy, Felice; Fiszdon, Joanna M.

2014-01-01

Despite the important role of motivation in rehabilitation and functional outcomes in schizophrenia, to date, there has been little emphasis on how motivation is assessed. This is important, since different measures may tap potentially discrete motivational constructs, which in turn may have very different associations to important outcomes. In the current study, we used baseline data from 71 schizophrenia spectrum outpatients enrolled in a rehabilitation program to examine the relationship between task-specific motivation, as measured by the Intrinsic Motivation Inventory (IMI), and a more general state of volition/initiation, as measured by the three item Quality of Life (QLS) motivation index. We also examined the relationship of these motivation measures to demographic, clinical and functional variables relevant to rehabilitation outcomes. The two motivation measures were not correlated, and participants with low general state motivation exhibited a full range of task-specific motivation. Only the QLS motivation index correlated with variables relevant to rehabilitation outcomes. The lack of associations between QLS motivation index and IMI subscales suggests that constructs tapped by these measures may be divergent in schizophrenia, and specifically that task-specific intrinsic motivation is not contingent on a general state of motivation. That is, even in individuals with a general low motivational state (i.e. amotivation), interventions aimed at increasing task-specific motivation may still be effective. Moreover, the pattern of interrelationships between the QLS motivation index and variables relevant to psychosocial rehabilitation supports its use in treatment outcome studies. PMID:24529609

Psychiatric rehabilitation in community-based day centres: motivation and satisfaction.

Science.gov (United States)

Eklund, Mona; Tjörnstrand, Carina

2013-11-01

This study investigated attendees' motivation and motives for participation in day centres and their satisfaction with the rehabilitation, while also addressing the influence of day centre orientation (work- or meeting-place orientation), gender and age. Ninety-three Swedish day centre attendees participated in a cross-sectional study and completed questionnaires about motivation, motives, and satisfaction with the rehabilitation. Data were analysed with non-parametric statistics. The participants were highly motivated for going to the day centre and set clear goals for their rehabilitation. Female gender, but not age, was associated with stronger motivation. The strongest motives for going to the day centre were getting structure to the day and socializing. Attendees at work-oriented day centres more often expressed that they went there to get structure to the day and gain social status. Satisfaction with the rehabilitation was high, and the most common wishes for further opportunities concerned earning money and learning new things. The rehabilitation largely seemed to meet the attendees' needs, but the findings indicated that further developments were desired, such as participation in work on the open market and more work-like occupations in the day centre, accompanied by some kind of remuneration.

Innovation, ENBIS and the Importance of Practice in the Development of Statistics.

NARCIS (Netherlands)

Bisgaard, S.

2005-01-01

The theme of this paper is innovation - in statistics and, more generally, in business and industry. Innovations in statistical theory have historically frequently occurred in direct response to demands for solutions to important practical problems. A major motivation for the establishment of the

Inter-observer and intra-observer agreement on interpretation of uroflowmetry curves of kindergarten children.

Science.gov (United States)

Chang, Shang-Jen; Yang, Stephen S D

2008-12-01

To evaluate the inter-observer and intra-observer agreement on the interpretation of uroflowmetry curves of children. Healthy kindergarten children were enrolled for evaluation of uroflowmetry. Uroflowmetry curves were classified as bell-shaped, tower, plateau, staccato and interrupted. Only the bell-shaped curves were regarded as normal. Two urodynamists evaluated the curves independently after reviewing the definitions of the different types of uroflowmetry curve. The senior urodynamist evaluated the curves twice 3 months apart. The final conclusion was made when consensus was reached. Agreement among observers was analyzed using kappa statistics. Of 190 uroflowmetry curves eligible for analysis, the intra-observer agreement in interpreting each type of curve and interpreting normalcy vs abnormality was good (kappa=0.71 and 0.68, respectively). Very good inter-observer agreement (kappa=0.81) on normalcy and good inter-observer agreement (kappa=0.73) on types of uroflowmetry were observed. Poor inter-observer agreement existed on the classification of specific types of abnormal uroflowmetry curves (kappa=0.07). Uroflowmetry is a good screening tool for normalcy of kindergarten children, while not a good tool to define the specific types of abnormal uroflowmetry.

Motivation.

Science.gov (United States)

Chambers, David W

2007-01-01

Motivation is short-term focused energy. The oldest theories of motivation explain motivated activity as effort to overcome primary deficiencies, such as hunger or boredom. Such theories are difficult to apply because individuals learn idiosyncratic secondary motives as alternative ways of responding to these needs. Three prominent needs theories are discussed: Herzberg's theory of hygiene and motivational factors; McClelland's needs for achievement, power, and affiliation; and Maslow's hierarchy and theory of self-actualization. A second approach to motivation holds that individuals may be thought of as engaging in rational processes to maximize their self-interests. The presented examples of this approach include Vroom's expectancy theory, Adam's theory of inequality, and the Porter-Lawler model that addresses the question of whether satisfaction leads to high performance or vice versa. Finally, several theories of motivation as life orientation are developed.

The Study of Second Higher Education through Mathematical Statistics

Directory of Open Access Journals (Sweden)

Olga V. Kremer

2014-05-01

Full Text Available The article deals with the statistic reasons, age and wages of people who get the second higher education. People opt for the second higher education mostly due to many economical and physiological factors. According to our research, the age is a key motivator for the second higher education. Based on statistical data the portrait of a second higher education student was drawn.

Motivational factors and performance in soccer

Directory of Open Access Journals (Sweden)

Maria Cristina Chimelo Paim

2008-06-01

Full Text Available This study aimed to verify what were the motivational factors that made teenagers to choose ADUFSM soccer school, and to verify the difference among the groups, the performance and gain scores at soccer basis. The sample comprised 32 persons, 10 to 16 years old, that practice soccer at ADUFSM. The sample was divided in four groups. The motivational factors inventory (MFI was applied in the beginning of the semester. It was verified, through descriptive statistics, that the stronger motivation for the subjects involvement with soccer was to develop skills (78%, followed by excitation and challenge (72%; affiliation (70% and aptitude (68%. The performance level evaluation in three different phases was done through soccer basis analytical matrix (SBAM, always in game situation. Five observations per subject were made for each base listed in SBAM, and the execution mistakes were identifies. Initially, an ANOVA was used to deal with the data; later, a post-hoc test. The results showed that learning occurred and that there was a significant difference favoring GF10 in the learning gain scores after the treatment.

Assessment the effect of the CBT on motivation of the nursing students.

Science.gov (United States)

Mehrabi, Tayebeh; Behzadi, Somayeh; Sabouri, Farhad; Alavi, Mousa

2016-01-01

Motivation to academic achievement is critical for students of medical sciences, particularly nursing students. It is directly related to high levels of achievement and quality of life. Accordingly, diminished motivation would result in academic decline, study and work desertion and exhaustion. Therefore, this study aimed to investigate the effect of cognitive behavioural intervention on the motivation for academic achievement of the nursing students. This study was conducted on 64 female nursing students who were recruited to study based on the inclusion criteria. After sampling, the subjects were randomly assigned to study and control groups. Then, cognitive behavioural intervention was administered in study group during 60 days. Academic motivation scale was filled before, after and one month after the intervention. Data were analyzed by descriptive and inferential statistical tests (Chi-square, t-test). After the intervention, mean scores of academic motivation were significantly increased in study group, compared to control group (P academic motivation in two groups revealed a significant increase in mean score of academic motivation 151.50 (20.22) after cognitive behavioural intervention (P academic achievement motivation among nursing students.

Effects of Warming up with Music on Moods and Training Motivation among Athletes

Directory of Open Access Journals (Sweden)

Golnaz Khazdozi

2017-02-01

Full Text Available The purpose of the present study is to review the effects of warming up with music on moods and training motivation among Kurdistan province’s female handball players0 for this purpose, 24 handball players of premier league of Kurdistan province were selected as the research subjects through a random sampling method. In this study a pretest-posttest design is applied by which 12 subjects have been selected as control group and 12 as experimental group. The latter group performed warm ups free from music. For the purpose of estimation of motivation of subjects, the questionnaire of sports motivation was made use of. In addition, for investigation of the moods variable, the questionnaire of athletes’ moods was used. Research results using the statistical test of Mann-Whitney showed that no significant difference existed between the experimental and control groups’ motivation and moods after performance of the warming up program (P: 0.124. This was while there was a statistically significant difference between the experimental and control groups’ moods prior and post to execution of Training program (P= 0.003. In general, it may be concluded that playing music doesn’t have any significant effects on athletes’ motivation while their moods can undergo significant changes through listening to music during warming up.

Effects of Warming Up With Music on Moods and Training Motivation among Athletes

Directory of Open Access Journals (Sweden)

Golnaz Khazdozi

2017-04-01

Full Text Available The purpose of the present study is to review the effects of warming up with music on moods and training motivation among Kurdistan province’s female handball players0 for this purpose, 24 handball players of premier league of Kurdistan province were selected as the research subjects through a random sampling method. In this study a pretest-posttest design is applied by which 12 subjects have been selected as control group and 12 as experimental group. The latter group performed warm ups free from music. For the purpose of estimation of motivation of subjects, the questionnaire of sports motivation was made use of. In addition, for investigation of the moods variable, the questionnaire of athletes’ moods was used. Research results using the statistical test of Mann-Whitney showed that no significant difference existed between the experimental and control groups’ motivation and moods after performance of the warming up program (P: 0.124. This was while there was a statistically significant difference between the experimental and control groups’ moods prior and post to execution of Training program (P= 0.003. In general, it may be concluded that playing music doesn’t have any significant effects on athletes’ motivation while their moods can undergo significant changes through listening to music during warming up.

Benefit and cost curves for typical pollination mutualisms.

Science.gov (United States)

Morris, William F; Vázquez, Diego P; Chacoff, Natacha P

2010-05-01

Mutualisms provide benefits to interacting species, but they also involve costs. If costs come to exceed benefits as population density or the frequency of encounters between species increases, the interaction will no longer be mutualistic. Thus curves that represent benefits and costs as functions of interaction frequency are important tools for predicting when a mutualism will tip over into antagonism. Currently, most of what we know about benefit and cost curves in pollination mutualisms comes from highly specialized pollinating seed-consumer mutualisms, such as the yucca moth-yucca interaction. There, benefits to female reproduction saturate as the number of visits to a flower increases (because the amount of pollen needed to fertilize all the flower's ovules is finite), but costs continue to increase (because pollinator offspring consume developing seeds), leading to a peak in seed production at an intermediate number of visits. But for most plant-pollinator mutualisms, costs to the plant are more subtle than consumption of seeds, and how such costs scale with interaction frequency remains largely unknown. Here, we present reasonable benefit and cost curves that are appropriate for typical pollinator-plant interactions, and we show how they can result in a wide diversity of relationships between net benefit (benefit minus cost) and interaction frequency. We then use maximum-likelihood methods to fit net-benefit curves to measures of female reproductive success for three typical pollination mutualisms from two continents, and for each system we chose the most parsimonious model using information-criterion statistics. We discuss the implications of the shape of the net-benefit curve for the ecology and evolution of plant-pollinator mutualisms, as well as the challenges that lie ahead for disentangling the underlying benefit and cost curves for typical pollination mutualisms.

Condition of esthetic component of motive activity in aerobic gymnastics

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Valentina Todorova

2017-02-01

Full Text Available Purpose: to prove condition of esthetic component of motive activity of sportsmen in aerobic gymnastics at various stages of sports preparation. Material & Methods: analysis of video records, method of expert assessment, methods of mathematical statistics. Results: the level of criteria of esthetic component ("musicality", "dancing", "illustrative expressiveness", and "emotional expressiveness" with use of the offered rating scale is determined. Conclusions: indicators of motive activities of sportsmen for aerobic gymnastics are defined at various stages of sports preparation.

Introduction to probability and statistics for engineers and scientists

CERN Document Server

Ross, Sheldon M

2009-01-01

This updated text provides a superior introduction to applied probability and statistics for engineering or science majors. Ross emphasizes the manner in which probability yields insight into statistical problems; ultimately resulting in an intuitive understanding of the statistical procedures most often used by practicing engineers and scientists. Real data sets are incorporated in a wide variety of exercises and examples throughout the book, and this emphasis on data motivates the probability coverage.As with the previous editions, Ross' text has remendously clear exposition, plus real-data

Incorporating Experience Curves in Appliance Standards Analysis

Energy Technology Data Exchange (ETDEWEB)

Garbesi, Karina; Chan, Peter; Greenblatt, Jeffery; Kantner, Colleen; Lekov, Alex; Meyers, Stephen; Rosenquist, Gregory; Buskirk, Robert Van; Yang, Hung-Chia; Desroches, Louis-Benoit

2011-10-31

The technical analyses in support of U.S. energy conservation standards for residential appliances and commercial equipment have typically assumed that manufacturing costs and retail prices remain constant during the projected 30-year analysis period. There is, however, considerable evidence that this assumption does not reflect real market prices. Costs and prices generally fall in relation to cumulative production, a phenomenon known as experience and modeled by a fairly robust empirical experience curve. Using price data from the Bureau of Labor Statistics, and shipment data obtained as part of the standards analysis process, we present U.S. experience curves for room air conditioners, clothes dryers, central air conditioners, furnaces, and refrigerators and freezers. These allow us to develop more representative appliance price projections than the assumption-based approach of constant prices. These experience curves were incorporated into recent energy conservation standards for these products. The impact on the national modeling can be significant, often increasing the net present value of potential standard levels in the analysis. In some cases a previously cost-negative potential standard level demonstrates a benefit when incorporating experience. These results imply that past energy conservation standards analyses may have undervalued the economic benefits of potential standard levels.

Beyond job security and money: driving factors of motivation for government doctors in India.

Science.gov (United States)

Purohit, Bhaskar; Bandyopadhyay, Tathagata

2014-02-21

Despite many efforts from government to address the shortage of medical officers (MOs) in rural areas, rural health centres continue to suffer from severe shortage of MOs. Lack of motivation to join and continue service in rural areas is a major reason for such shortage. In the present study, we aimed to assess and rank the driving factors of motivation important for in-service MOs in their current job. The study participants included ninety two in-service government MOs from three states in India. The study participants were required to rank 14 factors of motivation important for them in their current job. The factors for the study were selected using Herzberg's two-factor theory of motivation and the data were collected using an instrument that has an established reliability and validity. Test of Kendall's coefficient of concordance (W) was carried out to assess the agreement in ranks assigned by participants to various motivation factors. Next, we studied the distributions of ranks of different motivating factors using standard descriptive statistics and box plots, which gave us interesting insights into the strength of agreement of the MOs in assigning ranks to various factors. And finally to assess whether MOs are more intrinsically motivated or extrinsically motivated, we used Kolmogorov-Smirnov test. The (W) test indicated statistically significant (P factors than to extrinsic factors. The study results indicate that job security was the most important factor related to motivation, closely followed by interesting work and respect and recognition. Among the top five preferred factors, three were intrinsic factors indicating a great importance given by MOs to factors beyond money and job security. To address the issue of motivation, the health departments need to pay close attention to devising management strategies that address not only extrinsic but also intrinsic factors of motivation. The study results may be useful to understand the complicated issue of

A dose-surviving fraction curve for mouse colonic mucosa

International Nuclear Information System (INIS)

Tucker, S.L.; Thames, H.D. Jr.; Withers, H.R.; Mason, K.A.

1983-01-01

A dose-surviving fraction curve representing the response of the mouse colonic mucosa to single doses of 137 Cs gamma radiation was obtained from the results of a multifraction in vivo colony assay. Construction of the curve required an estimated of the average number of clonogens initially present per colonic crypt. The estimated clonogen count (88) was determined by a statistical method based on the use of doses per fraction common to different fractionation protocols. Parameters for the LQ and TC models of cell survival were obtained by weighted least-squares fits to the data. A comparison of the survival characteristics of cells from the mouse colonic and jejunal crypts suggested that the epithelium of the colon is less radiosensitive than that of the jejunum. (author)

Are the Motivational Effects of Autonomy-Supportive Conditions Universal? Contrasting Results Among Indians and Americans.

Science.gov (United States)

Tripathi, Ritu; Cervone, Daniel; Savani, Krishna

2018-04-01

In Western theories of motivation, autonomy is conceived as a universal motivator of human action; enhancing autonomy is expected to increase motivation panculturally. Using a novel online experimental paradigm that afforded a behavioral measure of motivation, we found that, contrary to this prevailing view, autonomy cues affect motivation differently among American and Indian corporate professionals. Autonomy-supportive instructions increased motivation among Americans but decreased motivation among Indians. The motivational Cue × Culture interaction was extraordinarily large; the populations exhibited little statistical overlap. A second study suggested that this interaction reflects culturally specific norms that are widely understood by members of the given culture. When evaluating messages to motivate workers, Indians, far more than Americans, preferred a message invoking obligations to one invoking autonomous personal choice norms. Results cast doubt on the claim, made regularly in both basic and applied psychology, that enhancing autonomy is a universally preferred method for boosting motivation.

The statistical process control methods - SPC

Directory of Open Access Journals (Sweden)

Floreková Ľubica

1998-03-01

Full Text Available Methods of statistical evaluation of quality – SPC (item 20 of the documentation system of quality control of ISO norm, series 900 of various processes, products and services belong amongst basic qualitative methods that enable us to analyse and compare data pertaining to various quantitative parameters. Also they enable, based on the latter, to propose suitable interventions with the aim of improving these processes, products and services. Theoretical basis and applicatibily of the principles of the: - diagnostics of a cause and effects, - Paret analysis and Lorentz curve, - number distribution and frequency curves of random variable distribution, - Shewhart regulation charts, are presented in the contribution.

Fostering Self-Concept and Interest for Statistics through Specific Learning Environments

Science.gov (United States)

Sproesser, Ute; Engel, Joachim; Kuntze, Sebastian

2016-01-01

Supporting motivational variables such as self-concept or interest is an important goal of schooling as they relate to learning and achievement. In this study, we investigated whether specific interest and self-concept related to the domains of statistics and mathematics can be fostered through a four-lesson intervention focusing on statistics.…

Learning curves for mutual information maximization

International Nuclear Information System (INIS)

Urbanczik, R.

2003-01-01

An unsupervised learning procedure based on maximizing the mutual information between the outputs of two networks receiving different but statistically dependent inputs is analyzed [S. Becker and G. Hinton, Nature (London) 355, 161 (1992)]. For a generic data model, I show that in the large sample limit the structure in the data is recognized by mutual information maximization. For a more restricted model, where the networks are similar to perceptrons, I calculate the learning curves for zero-temperature Gibbs learning. These show that convergence can be rather slow, and a way of regularizing the procedure is considered

Flood damage curves for consistent global risk assessments

Science.gov (United States)

de Moel, Hans; Huizinga, Jan; Szewczyk, Wojtek

2016-04-01

Assessing potential damage of flood events is an important component in flood risk management. Determining direct flood damage is commonly done using depth-damage curves, which denote the flood damage that would occur at specific water depths per asset or land-use class. Many countries around the world have developed flood damage models using such curves which are based on analysis of past flood events and/or on expert judgement. However, such damage curves are not available for all regions, which hampers damage assessments in those regions. Moreover, due to different methodologies employed for various damage models in different countries, damage assessments cannot be directly compared with each other, obstructing also supra-national flood damage assessments. To address these problems, a globally consistent dataset of depth-damage curves has been developed. This dataset contains damage curves depicting percent of damage as a function of water depth as well as maximum damage values for a variety of assets and land use classes (i.e. residential, commercial, agriculture). Based on an extensive literature survey concave damage curves have been developed for each continent, while differentiation in flood damage between countries is established by determining maximum damage values at the country scale. These maximum damage values are based on construction cost surveys from multinational construction companies, which provide a coherent set of detailed building cost data across dozens of countries. A consistent set of maximum flood damage values for all countries was computed using statistical regressions with socio-economic World Development Indicators from the World Bank. Further, based on insights from the literature survey, guidance is also given on how the damage curves and maximum damage values can be adjusted for specific local circumstances, such as urban vs. rural locations, use of specific building material, etc. This dataset can be used for consistent supra

Statistical analysis of quality control of automatic processor

International Nuclear Information System (INIS)

Niu Yantao; Zhao Lei; Zhang Wei; Yan Shulin

2002-01-01

Objective: To strengthen the scientific management of automatic processor and promote QC, based on analyzing QC management chart for automatic processor by statistical method, evaluating and interpreting the data and trend of the chart. Method: Speed, contrast, minimum density of step wedge of film strip were measured everyday and recorded on the QC chart. Mean (x-bar), standard deviation (s) and range (R) were calculated. The data and the working trend were evaluated and interpreted for management decisions. Results: Using relative frequency distribution curve constructed by measured data, the authors can judge whether it is a symmetric bell-shaped curve or not. If not, it indicates a few extremes overstepping control limits possibly are pulling the curve to the left or right. If it is a normal distribution, standard deviation (s) is observed. When x-bar +- 2s lies in upper and lower control limits of relative performance indexes, it indicates the processor works in stable status in this period. Conclusion: Guided by statistical method, QC work becomes more scientific and quantified. The authors can deepen understanding and application of the trend chart, and improve the quality management to a new step

Type Ia Supernova Light Curve Inference: Hierarchical Models for Nearby SN Ia in the Optical and Near Infrared

Science.gov (United States)

Mandel, Kaisey; Kirshner, R. P.; Narayan, G.; Wood-Vasey, W. M.; Friedman, A. S.; Hicken, M.

2010-01-01

I have constructed a comprehensive statistical model for Type Ia supernova light curves spanning optical through near infrared data simultaneously. The near infrared light curves are found to be excellent standard candles (sigma(MH) = 0.11 +/- 0.03 mag) that are less vulnerable to systematic error from dust extinction, a major confounding factor for cosmological studies. A hierarchical statistical framework incorporates coherently multiple sources of randomness and uncertainty, including photometric error, intrinsic supernova light curve variations and correlations, dust extinction and reddening, peculiar velocity dispersion and distances, for probabilistic inference with Type Ia SN light curves. Inferences are drawn from the full probability density over individual supernovae and the SN Ia and dust populations, conditioned on a dataset of SN Ia light curves and redshifts. To compute probabilistic inferences with hierarchical models, I have developed BayeSN, a Markov Chain Monte Carlo algorithm based on Gibbs sampling. This code explores and samples the global probability density of parameters describing individual supernovae and the population. I have applied this hierarchical model to optical and near infrared data of over 100 nearby Type Ia SN from PAIRITEL, the CfA3 sample, and the literature. Using this statistical model, I find that SN with optical and NIR data have a smaller residual scatter in the Hubble diagram than SN with only optical data. The continued study of Type Ia SN in the near infrared will be important for improving their utility as precise and accurate cosmological distance indicators.

In depth analysis of motivational factors at work in the health industry

Directory of Open Access Journals (Sweden)

Sukhminder Jit Singh Bajwa

2010-01-01

Full Text Available Background: Motivation of health workers is necessary to generate the organizational commitment towards the patients and the hospital and therefore the knowledge about what motivates and satisfies them is very essential.The aim of the project was to investigate and analyze the various factors that help in motivation of the health workers while performing their clinical duties in the hospital. Materials and Methods: A simple random study was conducted among 100 employees of our institute, which included doctors, staff nurses and paramedical staff. One hundred employees from Gian Sagar Institute were chosen randomly for the purpose of our study. All the employees were enquired by the questionnaire method as well as by individual interviews regarding the various motivating and demotivating factors at the work place. Detailed enquiries were performed regarding the various aspects concerning the job factors and work satisfaction. All the answers and findings were observed and recorded. Results: Statistical Analysis Used: Simple non-parametric tests like mean, percentages and chi square tests were employed to analyze the data.The demographic profile of all the employees showed only minor differences which were statistically non-significant. Skills, task identity, task significance, autonomy, feedback, environment, job security and compensation were observed to be the important factors for the motivation of employees. The depth and the extent to which these factors were studied at work in the hospital showed remarkable differences. Conclusion: All the factors studied in this project are essential basis for organizational commitment, but feedback represents the factor with the highest motivation potential especially among the younger population.

Electron Energy Level Statistics in Graphene Quantum Dots

NARCIS (Netherlands)

De Raedt, H.; Katsnellson, M. I.; Katsnelson, M.I.

2008-01-01

Motivated by recent experimental observations of size quantization of electron energy levels in graphene quantum dots [7] we investigate the level statistics in the simplest tight-binding model for different dot shapes by computer simulation. The results are in a reasonable agreement with the

Network similarity and statistical analysis of earthquake seismic data

OpenAIRE

Deyasi, Krishanu; Chakraborty, Abhijit; Banerjee, Anirban

2016-01-01

We study the structural similarity of earthquake networks constructed from seismic catalogs of different geographical regions. A hierarchical clustering of underlying undirected earthquake networks is shown using Jensen-Shannon divergence in graph spectra. The directed nature of links indicates that each earthquake network is strongly connected, which motivates us to study the directed version statistically. Our statistical analysis of each earthquake region identifies the hub regions. We cal...

Parents' food choice motives and their associations with children's food preferences.

Science.gov (United States)

Russell, Catherine G; Worsley, Anthony; Liem, Djin G

2015-04-01

The objective was to investigate parents' motives for selecting foods for their children and the associations between these motives and children's food preferences. Cross-sectional survey. A modified version of the Food Choice Questionnaire was used to assess parents' food choice motives. Parents also reported children's liking/disliking of 176 food and beverage items on 5-point Likert scales. Patterns of food choice motives were examined with exploratory principal component analysis. Associations between motives and children's food preferences were assessed with linear regression while one-way and two-way ANOVA were used to test for sociodemographic differences. Two Australian cities. Parents (n 371) of 2-5-year-old children. Health, nutrition and taste were key motivators for parents, whereas price, political concerns and advertising were among the motives considered least important. The more parents' food choice for their children was driven by what their children wanted, the less children liked vegetables (β =-0·27, Pfoods (r=0·17, Pmotives (vegetables β=0·17, Pmotives bordered on statistical significance as predictors of children's fruit and vegetable preferences. Although parents appear well intentioned in their motives for selecting children's foods, there are gaps to be addressed in the nature of such motives (e.g. selecting foods in line with the child's desires) or the translation of health motives into healthy food choices.

Relationship of motivation for motherhood with some sociodemographic variables and gender identity

Directory of Open Access Journals (Sweden)

Vuletić Georgije M.

2016-01-01

Full Text Available Main goal of the research was to explore the relationship between motivation for motherhood and some of the sociodemographic variables which have been noticed as significant in the similar researches of other authors, as well as relation to the gender roles and gender identity, according to the model proposed by Sandra Bem. The study was conducted on the sample consisting of 571 female students in Belgrade. Statistically significant correlations are confirmed between motivation for motherhood and number of siblings, age of subject's mother and age of subject's mother at first birth. The highest correlation is found between motivation for motherhood and femininity. It is also proposed a preliminary questioner, as the first step of constructing an adequate instrument for measuring motivation for motherhood. The questioner is used for estimation of motivation for motherhood in this research.

Learning-curve estimation techniques for nuclear industry

Energy Technology Data Exchange (ETDEWEB)

Vaurio, J.K.

1983-01-01

Statistical techniques are developed to estimate the progress made by the nuclear industry in learning to prevent accidents. Learning curves are derived for accident occurrence rates based on acturial data, predictions are made for the future, and compact analytical equations are obtained for the statistical accuracies of the estimates. Both maximum likelihood estimation and the method of moments are applied to obtain parameters for the learning models, and results are compared to each other and to earlier graphical and analytical results. An effective statistical test is also derived to assess the significance of trends. The models used associate learning directly to accidents, to the number of plants and to the cumulative number of operating years. Using as a data base nine core damage accidents in electricity-producing plants, it is estimated that the probability of a plant to have a serious flaw has decreased from 0.1 to 0.01 during the developmental phase of the nuclear industry. At the same time the frequency of accidents has decreased from 0.04 per reactor year to 0.0004 per reactor year.

Learning-curve estimation techniques for nuclear industry

International Nuclear Information System (INIS)

Vaurio, J.K.

1983-01-01

Statistical techniques are developed to estimate the progress made by the nuclear industry in learning to prevent accidents. Learning curves are derived for accident occurrence rates based on acturial data, predictions are made for the future, and compact analytical equations are obtained for the statistical accuracies of the estimates. Both maximum likelihood estimation and the method of moments are applied to obtain parameters for the learning models, and results are compared to each other and to earlier graphical and analytical results. An effective statistical test is also derived to assess the significance of trends. The models used associate learning directly to accidents, to the number of plants and to the cumulative number of operating years. Using as a data base nine core damage accidents in electricity-producing plants, it is estimated that the probability of a plant to have a serious flaw has decreased from 0.1 to 0.01 during the developmental phase of the nuclear industry. At the same time the frequency of accidents has decreased from 0.04 per reactor year to 0.0004 per reactor year

Learning curve estimation techniques for nuclear industry

International Nuclear Information System (INIS)

Vaurio, Jussi K.

1983-01-01

Statistical techniques are developed to estimate the progress made by the nuclear industry in learning to prevent accidents. Learning curves are derived for accident occurrence rates based on actuarial data, predictions are made for the future, and compact analytical equations are obtained for the statistical accuracies of the estimates. Both maximum likelihood estimation and the method of moments are applied to obtain parameters for the learning models, and results are compared to each other and to earlier graphical and analytical results. An effective statistical test is also derived to assess the significance of trends. The models used associate learning directly to accidents, to the number of plants and to the cumulative number of operating years. Using as a data base nine core damage accidents in electricity-producing plants, it is estimated that the probability of a plant to have a serious flaw has decreased from 0.1 to 0.01 during the developmental phase of the nuclear industry. At the same time the frequency of accidents has decreased from 0.04 per reactor year to 0.0004 per reactor year

Motivation, Prosocial and Antisocial Behaviors of Juveniles in Compare to Wellbehaved Peers

Directory of Open Access Journals (Sweden)

Hubert Kupiec

2013-12-01

Full Text Available The article contain results of research which participants were 104 juvenile delinquent and 294 adolescents from public schools. The statistic analyses show that juveniles have similar level of prosocial motivation as their well behaving peers from schools. However, gender is significant differentiation factor because girls have higher prosocial motivation and more frequently behave prosocially than boys in both compared groups. Juveniles exhibit less prosocial behavior than antisocial to relatives and friends, compared to their peers from schools, also. This paper include discussion of results and practical recommendations how we can develope motivation and prosocial behavior among juvenile delinquents.

Modeling error distributions of growth curve models through Bayesian methods.

Science.gov (United States)

Zhang, Zhiyong

2016-06-01

Growth curve models are widely used in social and behavioral sciences. However, typical growth curve models often assume that the errors are normally distributed although non-normal data may be even more common than normal data. In order to avoid possible statistical inference problems in blindly assuming normality, a general Bayesian framework is proposed to flexibly model normal and non-normal data through the explicit specification of the error distributions. A simulation study shows when the distribution of the error is correctly specified, one can avoid the loss in the efficiency of standard error estimates. A real example on the analysis of mathematical ability growth data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998-99 is used to show the application of the proposed methods. Instructions and code on how to conduct growth curve analysis with both normal and non-normal error distributions using the the MCMC procedure of SAS are provided.

Pharmacy students' test-taking motivation-effort on a low-stakes standardized test.

Science.gov (United States)

Waskiewicz, Rhonda A

2011-04-11

To measure third-year pharmacy students' level of motivation while completing the Pharmacy Curriculum Outcomes Assessment (PCOA) administered as a low-stakes test to better understand use of the PCOA as a measure of student content knowledge. Student motivation was manipulated through an incentive (ie, personal letter from the dean) and a process of statistical motivation filtering. Data were analyzed to determine any differences between the experimental and control groups in PCOA test performance, motivation to perform well, and test performance after filtering for low motivation-effort. Incentivizing students diminished the need for filtering PCOA scores for low effort. Where filtering was used, performance scores improved, providing a more realistic measure of aggregate student performance. To ensure that PCOA scores are an accurate reflection of student knowledge, incentivizing and/or filtering for low motivation-effort among pharmacy students should be considered fundamental best practice when the PCOA is administered as a low-stakes test.

Arctic curves in path models from the tangent method

Science.gov (United States)

Di Francesco, Philippe; Lapa, Matthew F.

2018-04-01

Recently, Colomo and Sportiello introduced a powerful method, known as the tangent method, for computing the arctic curve in statistical models which have a (non- or weakly-) intersecting lattice path formulation. We apply the tangent method to compute arctic curves in various models: the domino tiling of the Aztec diamond for which we recover the celebrated arctic circle; a model of Dyck paths equivalent to the rhombus tiling of a half-hexagon for which we find an arctic half-ellipse; another rhombus tiling model with an arctic parabola; the vertically symmetric alternating sign matrices, where we find the same arctic curve as for unconstrained alternating sign matrices. The latter case involves lattice paths that are non-intersecting but that are allowed to have osculating contact points, for which the tangent method was argued to still apply. For each problem we estimate the large size asymptotics of a certain one-point function using LU decomposition of the corresponding Gessel–Viennot matrices, and a reformulation of the result amenable to asymptotic analysis.

An appraisal of the learning curve in robotic general surgery.

Science.gov (United States)

Pernar, Luise I M; Robertson, Faith C; Tavakkoli, Ali; Sheu, Eric G; Brooks, David C; Smink, Douglas S

2017-11-01

Robotic-assisted surgery is used with increasing frequency in general surgery for a variety of applications. In spite of this increase in usage, the learning curve is not yet defined. This study reviews the literature on the learning curve in robotic general surgery to inform adopters of the technology. PubMed and EMBASE searches yielded 3690 abstracts published between July 1986 and March 2016. The abstracts were evaluated based on the following inclusion criteria: written in English, reporting original work, focus on general surgery operations, and with explicit statistical methods. Twenty-six full-length articles were included in final analysis. The articles described the learning curves in colorectal (9 articles, 35%), foregut/bariatric (8, 31%), biliary (5, 19%), and solid organ (4, 15%) surgery. Eighteen of 26 (69%) articles report single-surgeon experiences. Time was used as a measure of the learning curve in all studies (100%); outcomes were examined in 10 (38%). In 12 studies (46%), the authors identified three phases of the learning curve. Numbers of cases needed to achieve plateau performance were wide-ranging but overlapping for different kinds of operations: 19-128 cases for colorectal, 8-95 for foregut/bariatric, 20-48 for biliary, and 10-80 for solid organ surgery. Although robotic surgery is increasingly utilized in general surgery, the literature provides few guidelines on the learning curve for adoption. In this heterogeneous sample of reviewed articles, the number of cases needed to achieve plateau performance varies by case type and the learning curve may have multiple phases as surgeons add more complex cases to their case mix with growing experience. Time is the most common determinant for the learning curve. The literature lacks a uniform assessment of outcomes and complications, which would arguably reflect expertise in a more meaningful way than time to perform the operation alone.

[Importance of perceived competition and motivation to the mental health of college athletes].

Science.gov (United States)

Castillo, Isabel; Molina-García, Javier; Alvarez, Octavio

2010-01-01

This research analyzes the direct and indirect relationships among self-motivation, perceived competition and psychological well-being and ill-being. Data from 491 Spanish college students (299 men and 192 women) who practice sports were collected using a cross-sectional design. Statistical analyses were carried out using structural equation modeling. Psychological well-being was directly fostered by perceived competition and indirectly by self- motivation. Furthermore, perceived competition was negatively associated with psychological ill-being. Perceived competition and self-motivation are important to the psychological well-being of college students and to avoiding ill-being.

Statistical analysis of fatigue strain-life data for carbon and low-alloy steels

International Nuclear Information System (INIS)

Keisler, J.; Chopra, O.K.; Shack, W.J.

1994-08-01

The existing fatigue strain vs. life (S-N) data, foreign and domestic, for carbon and low-alloy steels used in the construction of nuclear power plant components have been compiled and categorized according to material, loading, and environmental conditions. A statistical model has been developed for estimating the effects of the various test conditions on fatigue life. The results of a rigorous statistical analysis have been used to estimate the probability of initiating a fatigue crack. Data in the literature were reviewed to evaluate the effects of size, geometry, and surface finish of a component on its fatigue life. The fatigue S-N curves for components have been determined by applying design margins for size, geometry, and surface finish to crack initiation curves estimated from the model. The significance of the effect of environment on the current Code design curve and on the proposed interim design curves for carbon and low-alloy steels presented in NUREG/CR-5999 is discussed

Curve ball baseball, statistics, and the role of chance in the game

CERN Document Server

Bennett, Jay

2001-01-01

In its formative years, from the 1970s through the 1990s, sabermetrics was p- marily an amateur undertaking. Publications were aimed at a relatively small audience of baseball fans. To be sure, this ever-growing group of aficionados brought a lot of sophistication to baseball analysis, and were constantly looking for statistical insights beyond the listings of the top ten batters found in popular newspapers and magazines. But their influence on the baseball profession was very limited. A few consultants like Craig Wright developed temporary relati- ships with various teams, but none were able to stay long enough to create a p- manent sabermetrician staff position. (See Rob Neyer’s November 11, 2002, arti- 1 cle on ESPN. com. ) All of this changed, however, in 2002 with the hiring of Bill James by the Boston Red Sox. With that move, we have seen the admittance of the foremost proponent of sabermetrics into the top echelon of professional ba- ball management. The art and science of careful statistical analysi...

Optimal Sample Size for Probability of Detection Curves

International Nuclear Information System (INIS)

Annis, Charles; Gandossi, Luca; Martin, Oliver

2012-01-01

The use of Probability of Detection (POD) curves to quantify NDT reliability is common in the aeronautical industry, but relatively less so in the nuclear industry. The European Network for Inspection Qualification's (ENIQ) Inspection Qualification Methodology is based on the concept of Technical Justification, a document assembling all the evidence to assure that the NDT system in focus is indeed capable of finding the flaws for which it was designed. This methodology has become widely used in many countries, but the assurance it provides is usually of qualitative nature. The need to quantify the output of inspection qualification has become more important, especially as structural reliability modelling and quantitative risk-informed in-service inspection methodologies become more widely used. To credit the inspections in structural reliability evaluations, a measure of the NDT reliability is necessary. A POD curve provides such metric. In 2010 ENIQ developed a technical report on POD curves, reviewing the statistical models used to quantify inspection reliability. Further work was subsequently carried out to investigate the issue of optimal sample size for deriving a POD curve, so that adequate guidance could be given to the practitioners of inspection reliability. Manufacturing of test pieces with cracks that are representative of real defects found in nuclear power plants (NPP) can be very expensive. Thus there is a tendency to reduce sample sizes and in turn reduce the conservatism associated with the POD curve derived. Not much guidance on the correct sample size can be found in the published literature, where often qualitative statements are given with no further justification. The aim of this paper is to summarise the findings of such work. (author)

Syntactic discriminative language model rerankers for statistical machine translation

NARCIS (Netherlands)

Carter, S.; Monz, C.

2011-01-01

This article describes a method that successfully exploits syntactic features for n-best translation candidate reranking using perceptrons. We motivate the utility of syntax by demonstrating the superior performance of parsers over n-gram language models in differentiating between Statistical

Using a portable sulfide monitor as a motivational tool: a clinical study.

Science.gov (United States)

Uppal, Ranjit Singh; Malhotra, Ranjan; Grover, Vishakha; Grover, Deepak

2012-01-01

Bad breath has a significant impact on daily life of those who suffer from it. Oral malodor may rank only behind dental caries and periodontal disease as the cause of patient's visit to dentist. An aim of this study was to use a portable sulfide monitor as a motivational tool for encouraging the patients towards the better oral hygiene by correlating the plaque scores with sulfide monitor scores, and comparing the sulfide monitor scores before and after complete prophylaxis and 3 months after patient motivation. 30 patients with chronic periodontitis, having chief complaint of oral malodor participated in this study. At first visit, the plaque scores (P1) and sulfide monitor scores before (BCR1) and after complete oral prophylaxis (BCR2) were taken. Then the patients were motivated towards the better oral hygiene. After 3 months, plaque scores (P2) and sulfide monitor scores (BCR3) were recorded again. It was done using SPSS (student package software for statistical analysis). Paired sample test was performed. Statistically significant reduction in sulfide monitor scores was reported after the complete oral prophylaxis and 3 months after patient motivation. Plaque scores were significantly reduced after a period of 3 months. Plaque scores and breathchecker scores were positively correlated. An intensity of the oral malodor was positively correlated with the plaque scores. The portable sulfide monitor was efficacious in motivating the patients towards the better oral hygiene.

A comparison of South African and German extrinsic and intrinsic motivation

Directory of Open Access Journals (Sweden)

Robin Snelgar

2017-04-01

Aim: The main objective of this study was to investigate similarities and differences concerning extrinsic and intrinsic motivation in the workplace between German and South African cultures by examining individuals with working experience and tertiary education specifically. In addition, the research investigated differences in the motivation of respondents with regard to demographics such as gender, age and income. Setting: The setting took place in South Africa and Germany. Methods: In the study, exploratory factor analysis was utilised to prove validity of Cinar, Bektas and Aslan’s two-dimensional measure of extrinsic and intrinsic motivation. Moreover, analysis of variance and t-tests were used to show differences among demographic variables. Descriptive statistics such as means, central tendency and Cronbach’s alpha were also utilised. Results: The results revealed preferences for intrinsic motivational factors for the whole sample with higher levels of intrinsic motivation for the South African respondents compared to German respondents. Demographic characteristics played a minor role in determining levels of intrinsic motivation within individuals. Culture, however, played the biggest role in determining one’s levels of intrinsic or extrinsic motivation. Conclusion: These findings play an important role in explaining differences in motivation between the two countries Germany and South Africa. It highlights the important role that cultural differences play in shaping one’s form of motivation.

Stenting for curved lesions using a novel curved balloon: Preliminary experimental study.

Science.gov (United States)

Tomita, Hideshi; Higaki, Takashi; Kobayashi, Toshiki; Fujii, Takanari; Fujimoto, Kazuto

2015-08-01

Stenting may be a compelling approach to dilating curved lesions in congenital heart diseases. However, balloon-expandable stents, which are commonly used for congenital heart diseases, are usually deployed in a straight orientation. In this study, we evaluated the effect of stenting with a novel curved balloon considered to provide better conformability to the curved-angled lesion. In vitro experiments: A Palmaz Genesis(®) stent (Johnson & Johnson, Cordis Co, Bridgewater, NJ, USA) mounted on the Goku(®) curve (Tokai Medical Co. Nagoya, Japan) was dilated in vitro to observe directly the behavior of the stent and balloon assembly during expansion. Animal experiment: A short Express(®) Vascular SD (Boston Scientific Co, Marlborough, MA, USA) stent and a long Express(®) Vascular LD stent (Boston Scientific) mounted on the curved balloon were deployed in the curved vessel of a pig to observe the effect of stenting in vivo. In vitro experiments: Although the stent was dilated in a curved fashion, stent and balloon assembly also rotated conjointly during expansion of its curved portion. In the primary stenting of the short stent, the stent was dilated with rotation of the curved portion. The excised stent conformed to the curved vessel. As the long stent could not be negotiated across the mid-portion with the balloon in expansion when it started curving, the mid-portion of the stent failed to expand fully. Furthermore, the balloon, which became entangled with the stent strut, could not be retrieved even after complete deflation. This novel curved balloon catheter might be used for implantation of the short stent in a curved lesion; however, it should not be used for primary stenting of the long stent. Post-dilation to conform the stent to the angled vessel would be safer than primary stenting irrespective of stent length. Copyright © 2014 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

ROC-ing along: Evaluation and interpretation of receiver operating characteristic curves.

Science.gov (United States)

Carter, Jane V; Pan, Jianmin; Rai, Shesh N; Galandiuk, Susan

2016-06-01

It is vital for clinicians to understand and interpret correctly medical statistics as used in clinical studies. In this review, we address current issues and focus on delivering a simple, yet comprehensive, explanation of common research methodology involving receiver operating characteristic (ROC) curves. ROC curves are used most commonly in medicine as a means of evaluating diagnostic tests. Sample data from a plasma test for the diagnosis of colorectal cancer were used to generate a prediction model. These are actual, unpublished data that have been used to describe the calculation of sensitivity, specificity, positive predictive and negative predictive values, and accuracy. The ROC curves were generated to determine the accuracy of this plasma test. These curves are generated by plotting the sensitivity (true-positive rate) on the y axis and 1 - specificity (false-positive rate) on the x axis. Curves that approach closest to the coordinate (x = 0, y = 1) are more highly predictive, whereas ROC curves that lie close to the line of equality indicate that the result is no better than that obtained by chance. The optimum sensitivity and specificity can be determined from the graph as the point where the minimum distance line crosses the ROC curve. This point corresponds to the Youden index (J), a function of sensitivity and specificity used commonly to rate diagnostic tests. The area under the curve is used to quantify the overall ability of a test to discriminate between 2 outcomes. By following these simple guidelines, interpretation of ROC curves will be less difficult and they can then be interpreted more reliably when writing, reviewing, or analyzing scientific papers. Copyright © 2016 Elsevier Inc. All rights reserved.

Application of Parallel Hierarchical Matrices and Low-Rank Tensors in Spatial Statistics and Parameter Identification

KAUST Repository

Litvinenko, Alexander

2018-03-12

Part 1: Parallel H-matrices in spatial statistics 1. Motivation: improve statistical model 2. Tools: Hierarchical matrices 3. Matern covariance function and joint Gaussian likelihood 4. Identification of unknown parameters via maximizing Gaussian log-likelihood 5. Implementation with HLIBPro. Part 2: Low-rank Tucker tensor methods in spatial statistics

Human resource management tool of motivation and employees job ...

African Journals Online (AJOL)

Chi-square and correlation-co-efficient statistical methods were used to test the hypotheses. The following were the findings of the study: 1. There is significant relationship of employees motivation on their job satisfaction (2) There is a cordial relationship between management employees relationship and employees job ...

Motivating crowding theory - opening the black box of intrinsic motivation

DEFF Research Database (Denmark)

Jacobsen, Christian Bøtcher

2010-01-01

Public employees work for many other reasons than because they are paid for it. In other words, intrinsic motivation is an important determinant for their performance. Nonetheless, public sector organizations increasingly rely on extrinsic motivation factors such as monetary incentives to motivate...... employees. Motivation crowding theory claims that this may be at the expense of intrinsic motivation, if the extrinsic motivation factor is perceived to be controlling. On the other hand, intrinsic motivation will be enhanced (crowded in), if the extrinsic motivation factor is perceived to be supportive......, monetary incentives are found to cause different crowding effects for these different types of intrinsic motivation. The results call for more theoretical work on the drivers of motivation crowding effects and for practitioners to pay more attention to what type of intrinsic motivation is at stake, when...

Maximally Informative Stimuli and Tuning Curves for Sigmoidal Rate-Coding Neurons and Populations

Science.gov (United States)

McDonnell, Mark D.; Stocks, Nigel G.

2008-08-01

A general method for deriving maximally informative sigmoidal tuning curves for neural systems with small normalized variability is presented. The optimal tuning curve is a nonlinear function of the cumulative distribution function of the stimulus and depends on the mean-variance relationship of the neural system. The derivation is based on a known relationship between Shannon’s mutual information and Fisher information, and the optimality of Jeffrey’s prior. It relies on the existence of closed-form solutions to the converse problem of optimizing the stimulus distribution for a given tuning curve. It is shown that maximum mutual information corresponds to constant Fisher information only if the stimulus is uniformly distributed. As an example, the case of sub-Poisson binomial firing statistics is analyzed in detail.

Motivators and barriers to participating in health promotion behaviors in Black men.

Science.gov (United States)

Calvert, Wilma J; Isaac-Savage, E Paulette

2013-08-01

There is limited research examining the health promotion behaviors (HPBs) of low-income Black men. This study examined the relationship between HPBs, and motivators and barriers to participating in these behaviors in Black men (N = 107), aged 21 to 56. Using descriptive statistics, more than 96% of the participants reported they were motivated because of the desire to be healthy. Canonical correlation analysis and conditional random forest were used to determine the importance of individual motivators and barriers. Canonical correlation analysis yielded one interpretable canonical variate that explained 39.5% of the variance in sets of motivators and barriers, and health promotion lifestyle variables. Men with fewer motivators and more barriers took less responsibility for their health, participated in less physical activity, and reported less spiritual growth. Having too many things to do and not knowing what to do best predicted participation in HPBs.

JUMPING THE CURVE

Directory of Open Access Journals (Sweden)

René Pellissier

2012-01-01

Full Text Available This paper explores the notion ofjump ing the curve,following from Handy 's S-curve onto a new curve with new rules policies and procedures. . It claims that the curve does not generally lie in wait but has to be invented by leadership. The focus of this paper is the identification (mathematically and inferentially ofthat point in time, known as the cusp in catastrophe theory, when it is time to change - pro-actively, pre-actively or reactively. These three scenarios are addressed separately and discussed in terms ofthe relevance ofeach.

Successful innovation by motivation

Directory of Open Access Journals (Sweden)

Petra Koudelková

2015-10-01

Full Text Available Innovation is one of the most important factors for business growth. Human capital plays a significant role in the successful process of innovation. This article deals with employee motivation in the innovation process and the main scientific aim of this study is to present results of research that was undertaken in the Czech Republic at the beginning of 2013. Questionnaires were used for the survey and statistical analyses such as Chi square test or Hierarchical cluster analysis were used for data processing. This study also provides a theoretical and practical overview of business innovation in the Czech Republic.

S-curve networks and an approximate method for estimating degree distributions of complex networks

OpenAIRE

Guo, Jin-Li

2010-01-01

In the study of complex networks almost all theoretical models have the property of infinite growth, but the size of actual networks is finite. According to statistics from the China Internet IPv4 (Internet Protocol version 4) addresses, this paper proposes a forecasting model by using S curve (Logistic curve). The growing trend of IPv4 addresses in China is forecasted. There are some reference value for optimizing the distribution of IPv4 address resource and the development of IPv6. Based o...

SPOTTED STAR LIGHT CURVES WITH ENHANCED PRECISION

International Nuclear Information System (INIS)

Wilson, R. E.

2012-01-01

The nearly continuous timewise coverage of recent photometric surveys is free of the large gaps that compromise attempts to follow starspot growth and decay as well as motions, thereby giving incentive to improve computational precision for modeled spots. Due to the wide variety of star systems in the surveys, such improvement should apply to light/velocity curve models that accurately include all the main phenomena of close binaries and rotating single stars. The vector fractional area (VFA) algorithm that is introduced here represents surface elements by small sets of position vectors so as to allow accurate computation of circle-triangle overlap by spherical geometry. When computed by VFA, spots introduce essentially no noticeable scatter in light curves at the level of one part in 10,000. VFA has been put into the Wilson-Devinney light/velocity curve program and all logic and mathematics are given so as to facilitate entry into other such programs. Advantages of precise spot computation include improved statistics of spot motions and aging, reduced computation time (intrinsic precision relaxes needs for grid fineness), noise-free illustration of spot effects in figures, and help in guarding against false positives in exoplanet searches, where spots could approximately mimic transiting planets in unusual circumstances. A simple spot growth and decay template quantifies time profiles, and specifics of its utilization in differential corrections solutions are given. Computational strategies are discussed, the overall process is tested in simulations via solutions of synthetic light curve data, and essential simulation results are described. An efficient time smearing facility by Gaussian quadrature can deal with Kepler mission data that are in 30 minute time bins.

Enhanced secondary analysis of survival data: reconstructing the data from published Kaplan-Meier survival curves.

Science.gov (United States)

Guyot, Patricia; Ades, A E; Ouwens, Mario J N M; Welton, Nicky J

2012-02-01

The results of Randomized Controlled Trials (RCTs) on time-to-event outcomes that are usually reported are median time to events and Cox Hazard Ratio. These do not constitute the sufficient statistics required for meta-analysis or cost-effectiveness analysis, and their use in secondary analyses requires strong assumptions that may not have been adequately tested. In order to enhance the quality of secondary data analyses, we propose a method which derives from the published Kaplan Meier survival curves a close approximation to the original individual patient time-to-event data from which they were generated. We develop an algorithm that maps from digitised curves back to KM data by finding numerical solutions to the inverted KM equations, using where available information on number of events and numbers at risk. The reproducibility and accuracy of survival probabilities, median survival times and hazard ratios based on reconstructed KM data was assessed by comparing published statistics (survival probabilities, medians and hazard ratios) with statistics based on repeated reconstructions by multiple observers. The validation exercise established there was no material systematic error and that there was a high degree of reproducibility for all statistics. Accuracy was excellent for survival probabilities and medians, for hazard ratios reasonable accuracy can only be obtained if at least numbers at risk or total number of events are reported. The algorithm is a reliable tool for meta-analysis and cost-effectiveness analyses of RCTs reporting time-to-event data. It is recommended that all RCTs should report information on numbers at risk and total number of events alongside KM curves.

UNSUPERVISED TRANSIENT LIGHT CURVE ANALYSIS VIA HIERARCHICAL BAYESIAN INFERENCE

International Nuclear Information System (INIS)

Sanders, N. E.; Soderberg, A. M.; Betancourt, M.

2015-01-01

Historically, light curve studies of supernovae (SNe) and other transient classes have focused on individual objects with copious and high signal-to-noise observations. In the nascent era of wide field transient searches, objects with detailed observations are decreasing as a fraction of the overall known SN population, and this strategy sacrifices the majority of the information contained in the data about the underlying population of transients. A population level modeling approach, simultaneously fitting all available observations of objects in a transient sub-class of interest, fully mines the data to infer the properties of the population and avoids certain systematic biases. We present a novel hierarchical Bayesian statistical model for population level modeling of transient light curves, and discuss its implementation using an efficient Hamiltonian Monte Carlo technique. As a test case, we apply this model to the Type IIP SN sample from the Pan-STARRS1 Medium Deep Survey, consisting of 18,837 photometric observations of 76 SNe, corresponding to a joint posterior distribution with 9176 parameters under our model. Our hierarchical model fits provide improved constraints on light curve parameters relevant to the physical properties of their progenitor stars relative to modeling individual light curves alone. Moreover, we directly evaluate the probability for occurrence rates of unseen light curve characteristics from the model hyperparameters, addressing observational biases in survey methodology. We view this modeling framework as an unsupervised machine learning technique with the ability to maximize scientific returns from data to be collected by future wide field transient searches like LSST

UNSUPERVISED TRANSIENT LIGHT CURVE ANALYSIS VIA HIERARCHICAL BAYESIAN INFERENCE

Energy Technology Data Exchange (ETDEWEB)

Sanders, N. E.; Soderberg, A. M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Betancourt, M., E-mail: nsanders@cfa.harvard.edu [Department of Statistics, University of Warwick, Coventry CV4 7AL (United Kingdom)

2015-02-10

Historically, light curve studies of supernovae (SNe) and other transient classes have focused on individual objects with copious and high signal-to-noise observations. In the nascent era of wide field transient searches, objects with detailed observations are decreasing as a fraction of the overall known SN population, and this strategy sacrifices the majority of the information contained in the data about the underlying population of transients. A population level modeling approach, simultaneously fitting all available observations of objects in a transient sub-class of interest, fully mines the data to infer the properties of the population and avoids certain systematic biases. We present a novel hierarchical Bayesian statistical model for population level modeling of transient light curves, and discuss its implementation using an efficient Hamiltonian Monte Carlo technique. As a test case, we apply this model to the Type IIP SN sample from the Pan-STARRS1 Medium Deep Survey, consisting of 18,837 photometric observations of 76 SNe, corresponding to a joint posterior distribution with 9176 parameters under our model. Our hierarchical model fits provide improved constraints on light curve parameters relevant to the physical properties of their progenitor stars relative to modeling individual light curves alone. Moreover, we directly evaluate the probability for occurrence rates of unseen light curve characteristics from the model hyperparameters, addressing observational biases in survey methodology. We view this modeling framework as an unsupervised machine learning technique with the ability to maximize scientific returns from data to be collected by future wide field transient searches like LSST.

Dual Smarandache Curves of a Timelike Curve lying on Unit dual Lorentzian Sphere

OpenAIRE

Kahraman, Tanju; Hüseyin Ugurlu, Hasan

2016-01-01

In this paper, we give Darboux approximation for dual Smarandache curves of time like curve on unit dual Lorentzian sphere. Firstly, we define the four types of dual Smarandache curves of a timelike curve lying on dual Lorentzian sphere.

Organizational commitment and intrinsic motivation of regular and contractual primary health care providers.

Science.gov (United States)

Kumar, Pawan; Mehra, Anu; Inder, Deep; Sharma, Nandini

2016-01-01

Motivated and committed employees deliver better health care, which results in better outcomes and higher patient satisfaction. To assess the Organizational Commitment and Intrinsic Motivation of Primary Health Care Providers (HCPs) in New Delhi, India. Study was conducted in 2013 on a sample of 333 HCPs who were selected using multistage stage random sampling technique. The sample includes medical officers, auxiliary nurses and midwives, and pharmacists and laboratory technicians/assistants among regular and contractual staff. Data were collected using the pretested structured questionnaire for organization commitment (OC), job satisfiers, and intrinsic job motivation. Analysis was done by using SPSS version 18 and appropriate statistical tests were applied. The mean score for OC for entire regular staff is 1.6 ± 0.39 and contractual staff is 1.3 ± 0.45 which has statistically significant difference (t = 5.57; P = 0.00). In both regular and contractual staff, none of them show high emotional attachment with the organization and does not feel part of the family in the organization. Contractual staff does not feel proud to work in a present organization for rest of their career. Intrinsic motivation is high in both regular and contractual groups but intergroup difference is significant (t = 2.38; P Organizational commitment and intrinsic motivation of contractual staff are lesser than the permanent staff. Appropriate changes are required in the predictors of organizational commitment and factors responsible for satisfaction in the organization to keep the contractual human resource motivated and committed to the organization.

Estimation of Typhoon Wind Hazard Curves for Nuclear Sites

Energy Technology Data Exchange (ETDEWEB)

Choun, Young-Sun; Kim, Min-Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

The intensity of such typhoons, which can influence the Korean Peninsula, is on an increasing trend owing to a rapid change of climate of the Northwest Pacific Ocean. Therefore, nuclear facilities should be prepared against future super-typhoons. Currently, the U.S. Nuclear Regulatory Commission requires that a new NPP should be designed to endure the design-basis hurricane wind speeds corresponding to an annual exceedance frequency of 10{sup -7} (return period of 10 million years). A typical technique used to estimate typhoon wind speeds is based on a sampling of the key parameters of typhoon wind models from the distribution functions fitting statistical distributions to the observation data. Thus, the estimated wind speeds for long return periods include an unavoidable uncertainty owing to a limited observation. This study estimates the typhoon wind speeds for nuclear sites using a Monte Carlo simulation, and derives wind hazard curves using a logic-tree framework to reduce the epistemic uncertainty. Typhoon wind speeds were estimated for different return periods through a Monte-Carlo simulation using the typhoon observation data, and the wind hazard curves were derived using a logic-tree framework for three nuclear sites. The hazard curves for the simulated and probable maximum winds were obtained. The mean hazard curves for the simulated and probable maximum winds can be used for the design and risk assessment of an NPP.

THE INFLUENCE OF ORGANIZATIONAL CLIMATE, TRANSFORMATIONAL LEADERSHIP, AND WORK MOTIVATION ON TEACHER JOB PERFORMANCE

Directory of Open Access Journals (Sweden)

K. Kartini

2017-07-01

Full Text Available This research aimed at investigating the influence of organizational climate, transformational leadership, and work motivation on teacher job performance at Pondok Modern Tazakka, Batang - Central Java.The research using a quantitative approach with survey method. Amount of the samples in this research are 55 teachers that selected randomly. The data were analyzed by using descriptive statistics and inferential statistic using path analysis. (1 organizational climate have positive direct effect on teacher performance with path coefficient (py1 = 0,257 and t-count 2,963> t-table 1,684; (2 transformational leadership have positive direct effect on teacher performance with path coefficient (py2 = 0,489 and t-count 5,164> t-table 1,684, (3 work motivation have positive direct effect to teacher performance with path coefficient (py3 = 0,261 and t count 2,42> t-table 1,684, (4 organizational climate have positive direct effect (p31 = 0.391 and t-count 3.990> t-table 1.684, and (5 transformational leadership have a direct positive effect on work motivation with path coefficient (p32 = 0.526 and t-count 5,376> t- table 1,684. The Conclusion is organizational climate, transformational leadership, and work motivation have a direct effect on teacher job performance. Organizational climate and transformational leadership also have a direct effect on teacher work motivation. Therefore to improve teacher job performance, organizational climate, transformational leadership, and work motivation must be considered to be improved.

Relationship between time management skills and anxiety and academic motivation of nursing students in Tehran.

Science.gov (United States)

Ghiasvand, Arezoo Mohamadkhani; Naderi, Manijeh; Tafreshi, Mansoureh Zagheri; Ahmadi, Farzane; Hosseini, Meimanat

2017-01-01

Time management skills are essential for nursing students' success, and development of clinical competence. The purpose of this study was to determine the relationship between time management skills and anxiety and academic motivation of nursing students in Tehran medical sciences universities in 2015. This cross-sectional study was carried out on 441 nursing students in three medical universities in Tehran. Random stratified sampling was done to select the samples. Data were collected using demographic Questionnaire, Time Management Questionnaire (TMQ), Spielberger State-Trait Anxiety Inventory (STAI) and Academic Motivation Scale (AMS), which was completed t by self-report. Data were analyzed using SPSS 18 software with descriptive and analytical statistics such as ANOVA, independent t-test, Regression and Pearson Correlation Coefficient. Most participants had a moderate level of time Management skills (49%), State Anxiety (58%), Trait Anxiety (60%) and Academic Motivation (58%). The results also showed a statistically significant negative correlation between the students' TMQ scores and the state anxiety (r= -0.282, ptime management skills in order to enhance academic motivation and reduce anxiety rates among nursing students.

Motivation in Beyond Budgeting: A Motivational Paradox?

DEFF Research Database (Denmark)

Sandalgaard, Niels; Bukh, Per Nikolaj

In this paper we discuss the role of motivation in relation to budgeting and we analyse how the Beyond Budgeting model functions compared with traditional budgeting. In the paper we focus on budget related motivation (and motivation in general) and conclude that the Beyond Budgeting model...

Statistical treatment of fatigue test data

International Nuclear Information System (INIS)

Raske, D.T.

1980-01-01

This report discussed several aspects of fatigue data analysis in order to provide a basis for the development of statistically sound design curves. Included is a discussion on the choice of the dependent variable, the assumptions associated with least squares regression models, the variability of fatigue data, the treatment of data from suspended tests and outlying observations, and various strain-life relations

ECM using Edwards curves

DEFF Research Database (Denmark)

Bernstein, Daniel J.; Birkner, Peter; Lange, Tanja

2013-01-01

-arithmetic level are as follows: (1) use Edwards curves instead of Montgomery curves; (2) use extended Edwards coordinates; (3) use signed-sliding-window addition-subtraction chains; (4) batch primes to increase the window size; (5) choose curves with small parameters and base points; (6) choose curves with large...

Meta-analysis of single-arm survival studies: a distribution-free approach for estimating summary survival curves with random effects.

Science.gov (United States)

Combescure, Christophe; Foucher, Yohann; Jackson, Daniel

2014-07-10

In epidemiologic studies and clinical trials with time-dependent outcome (for instance death or disease progression), survival curves are used to describe the risk of the event over time. In meta-analyses of studies reporting a survival curve, the most informative finding is a summary survival curve. In this paper, we propose a method to obtain a distribution-free summary survival curve by expanding the product-limit estimator of survival for aggregated survival data. The extension of DerSimonian and Laird's methodology for multiple outcomes is applied to account for the between-study heterogeneity. Statistics I(2)  and H(2) are used to quantify the impact of the heterogeneity in the published survival curves. A statistical test for between-strata comparison is proposed, with the aim to explore study-level factors potentially associated with survival. The performance of the proposed approach is evaluated in a simulation study. Our approach is also applied to synthesize the survival of untreated patients with hepatocellular carcinoma from aggregate data of 27 studies and synthesize the graft survival of kidney transplant recipients from individual data from six hospitals. Copyright © 2014 John Wiley & Sons, Ltd.

"Statistical Techniques for Particle Physics" (2/4)

CERN Multimedia

CERN. Geneva

2009-01-01

This series will consist of four 1-hour lectures on statistics for particle physics. The goal will be to build up to techniques meant for dealing with problems of realistic complexity while maintaining a formal approach. I will also try to incorporate usage of common tools like ROOT, RooFit, and the newly developed RooStats framework into the lectures. The first lecture will begin with a review the basic principles of probability, some terminology, and the three main approaches towards statistical inference (Frequentist, Bayesian, and Likelihood-based). I will then outline the statistical basis for multivariate analysis techniques (the Neyman-Pearson lemma) and the motivation for machine learning algorithms. Later, I will extend simple hypothesis testing to the case in which the statistical model has one or many parameters (the Neyman Construction and the Feldman-Cousins technique). From there I will outline techniques to incorporate background uncertainties. If time allows, I will touch on the statist...

"Statistical Techniques for Particle Physics" (1/4)

CERN Multimedia

CERN. Geneva

2009-01-01

This series will consist of four 1-hour lectures on statistics for particle physics. The goal will be to build up to techniques meant for dealing with problems of realistic complexity while maintaining a formal approach. I will also try to incorporate usage of common tools like ROOT, RooFit, and the newly developed RooStats framework into the lectures. The first lecture will begin with a review the basic principles of probability, some terminology, and the three main approaches towards statistical inference (Frequentist, Bayesian, and Likelihood-based). I will then outline the statistical basis for multivariate analysis techniques (the Neyman-Pearson lemma) and the motivation for machine learning algorithms. Later, I will extend simple hypothesis testing to the case in which the statistical model has one or many parameters (the Neyman Construction and the Feldman-Cousins technique). From there I will outline techniques to incorporate background uncertainties. If time allows, I will touch on the statist...

"Statistical Techniques for Particle Physics" (4/4)

CERN Multimedia

CERN. Geneva

2009-01-01

This series will consist of four 1-hour lectures on statistics for particle physics. The goal will be to build up to techniques meant for dealing with problems of realistic complexity while maintaining a formal approach. I will also try to incorporate usage of common tools like ROOT, RooFit, and the newly developed RooStats framework into the lectures. The first lecture will begin with a review the basic principles of probability, some terminology, and the three main approaches towards statistical inference (Frequentist, Bayesian, and Likelihood-based). I will then outline the statistical basis for multivariate analysis techniques (the Neyman-Pearson lemma) and the motivation for machine learning algorithms. Later, I will extend simple hypothesis testing to the case in which the statistical model has one or many parameters (the Neyman Construction and the Feldman-Cousins technique). From there I will outline techniques to incorporate background uncertainties. If time allows, I will touch on the statist...

"Statistical Techniques for Particle Physics" (3/4)

CERN Multimedia

CERN. Geneva

2009-01-01

This series will consist of four 1-hour lectures on statistics for particle physics. The goal will be to build up to techniques meant for dealing with problems of realistic complexity while maintaining a formal approach. I will also try to incorporate usage of common tools like ROOT, RooFit, and the newly developed RooStats framework into the lectures. The first lecture will begin with a review the basic principles of probability, some terminology, and the three main approaches towards statistical inference (Frequentist, Bayesian, and Likelihood-based). I will then outline the statistical basis for multivariate analysis techniques (the Neyman-Pearson lemma) and the motivation for machine learning algorithms. Later, I will extend simple hypothesis testing to the case in which the statistical model has one or many parameters (the Neyman Construction and the Feldman-Cousins technique). From there I will outline techniques to incorporate background uncertainties. If time allows, I will touch on the statist...

Genomic growth curves of an outbred pig population

Directory of Open Access Journals (Sweden)

Fabyano Fonseca e Silva

2013-01-01

Full Text Available In the current post-genomic era, the genetic basis of pig growth can be understood by assessing SNP marker effects and genomic breeding values (GEBV based on estimates of these growth curve parameters as phenotypes. Although various statistical methods, such as random regression (RR-BLUP and Bayesian LASSO (BL, have been applied to genomic selection (GS, none of these has yet been used in a growth curve approach. In this work, we compared the accuracies of RR-BLUP and BL using empirical weight-age data from an outbred F2 (Brazilian Piau X commercial population. The phenotypes were determined by parameter estimates using a nonlinear logistic regression model and the halothane gene was considered as a marker for evaluating the assumptions of the GS methods in relation to the genetic variation explained by each locus. BL yielded more accurate values for all of the phenotypes evaluated and was used to estimate SNP effects and GEBV vectors. The latter allowed the construction of genomic growth curves, which showed substantial genetic discrimination among animals in the final growth phase. The SNP effect estimates allowed identification of the most relevant markers for each phenotype, the positions of which were coincident with reported QTL regions for growth traits.

Optimal sample size for probability of detection curves

International Nuclear Information System (INIS)

Annis, Charles; Gandossi, Luca; Martin, Oliver

2013-01-01

Highlights: • We investigate sample size requirement to develop probability of detection curves. • We develop simulations to determine effective inspection target sizes, number and distribution. • We summarize these findings and provide guidelines for the NDE practitioner. -- Abstract: The use of probability of detection curves to quantify the reliability of non-destructive examination (NDE) systems is common in the aeronautical industry, but relatively less so in the nuclear industry, at least in European countries. Due to the nature of the components being inspected, sample sizes tend to be much lower. This makes the manufacturing of test pieces with representative flaws, in sufficient numbers, so to draw statistical conclusions on the reliability of the NDT system under investigation, quite costly. The European Network for Inspection and Qualification (ENIQ) has developed an inspection qualification methodology, referred to as the ENIQ Methodology. It has become widely used in many European countries and provides assurance on the reliability of NDE systems, but only qualitatively. The need to quantify the output of inspection qualification has become more important as structural reliability modelling and quantitative risk-informed in-service inspection methodologies become more widely used. A measure of the NDE reliability is necessary to quantify risk reduction after inspection and probability of detection (POD) curves provide such a metric. The Joint Research Centre, Petten, The Netherlands supported ENIQ by investigating the question of the sample size required to determine a reliable POD curve. As mentioned earlier manufacturing of test pieces with defects that are typically found in nuclear power plants (NPPs) is usually quite expensive. Thus there is a tendency to reduce sample sizes, which in turn increases the uncertainty associated with the resulting POD curve. The main question in conjunction with POS curves is the appropriate sample size. Not

Statistical ultrasonics: the influence of Robert F. Wagner

Science.gov (United States)

Insana, Michael F.

2009-02-01

An important ongoing question for higher education is how to successfully mentor the next generation of scientists and engineers. It has been my privilege to have been mentored by one of the best, Dr Robert F. Wagner and his colleagues at the CDRH/FDA during the mid 1980s. Bob introduced many of us in medical ultrasonics to statistical imaging techniques. These ideas continue to broadly influence studies on adaptive aperture management (beamforming, speckle suppression, compounding), tissue characterization (texture features, Rayleigh/Rician statistics, scatterer size and number density estimators), and fundamental questions about how limitations of the human eye-brain system for extracting information from textured images can motivate image processing. He adapted the classical techniques of signal detection theory to coherent imaging systems that, for the first time in ultrasonics, related common engineering metrics for image quality to task-based clinical performance. This talk summarizes my wonderfully-exciting three years with Bob as I watched him explore topics in statistical image analysis that formed a rational basis for many of the signal processing techniques used in commercial systems today. It is a story of an exciting time in medical ultrasonics, and of how a sparkling personality guided and motivated the development of junior scientists who flocked around him in admiration and amazement.

On a framework for generating PoD curves assisted by numerical simulations

Energy Technology Data Exchange (ETDEWEB)

Subair, S. Mohamed, E-mail: prajagopal@iitm.ac.in; Agrawal, Shweta, E-mail: prajagopal@iitm.ac.in; Balasubramaniam, Krishnan, E-mail: prajagopal@iitm.ac.in; Rajagopal, Prabhu, E-mail: prajagopal@iitm.ac.in [Indian Institute of Technology Madras, Department of Mechanical Engineering, Chennai, T.N. (India); Kumar, Anish; Rao, Purnachandra B.; Tamanna, Jayakumar [Indira Gandhi Centre for Atomic Research, Metallurgy and Materials Group, Kalpakkam, T.N. (India)

2015-03-31

The Probability of Detection (PoD) curve method has emerged as an important tool for the assessment of the performance of NDE techniques, a topic of particular interest to the nuclear industry where inspection qualification is very important. The conventional experimental means of generating PoD curves though, can be expensive, requiring large data sets (covering defects and test conditions), and equipment and operator time. Several methods of achieving faster estimates for PoD curves using physics-based modelling have been developed to address this problem. Numerical modelling techniques are also attractive, especially given the ever-increasing computational power available to scientists today. Here we develop procedures for obtaining PoD curves, assisted by numerical simulation and based on Bayesian statistics. Numerical simulations are performed using Finite Element analysis for factors that are assumed to be independent, random and normally distributed. PoD curves so generated are compared with experiments on austenitic stainless steel (SS) plates with artificially created notches. We examine issues affecting the PoD curve generation process including codes, standards, distribution of defect parameters and the choice of the noise threshold. We also study the assumption of normal distribution for signal response parameters and consider strategies for dealing with data that may be more complex or sparse to justify this. These topics are addressed and illustrated through the example case of generation of PoD curves for pulse-echo ultrasonic inspection of vertical surface-breaking cracks in SS plates.

Effects of statistical quality, sampling rate and temporal filtering techniques on the extraction of functional parameters from the left ventricular time-activity curves

Energy Technology Data Exchange (ETDEWEB)

Guignard, P.A.; Chan, W. (Royal Melbourne Hospital, Parkville (Australia). Dept. of Nuclear Medicine)

1984-09-01

Several techniques for the processing of a series of curves derived from two left ventricular time-activity curves acquired at rest and during exercise with a nuclear stethoscope were evaluated. They were three and five point time smoothing. Fourier filtering preserving one to four harmonics (H), truncated curve Fourier filtering, and third degree polynomial curve fitting. Each filter's ability to recover, with fidelity, systolic and diastolic function parameters was evaluated under increasingly 'noisy' conditions and at several sampling rates. Third degree polynomial curve fittings and truncated Fourier filters exhibited very high sensitivity to noise. Three and five point time smoothing had moderate sensitivity to noise, but were highly affected by sampling rate. Fourier filtering preserving 2H or 3H produced the best compromise with high resilience to noise and independence of sampling rate as far as the recovery of these functional parameters is concerned.

Effects of statistical quality, sampling rate and temporal filtering techniques on the extraction of functional parameters from the left ventricular time-activity curves

International Nuclear Information System (INIS)

Guignard, P.A.; Chan, W.

1984-01-01

Several techniques for the processing of a series of curves derived from two left ventricular time-activity curves acquired at rest and during exercise with a nuclear stethoscope were evaluated. They were three and five point time smoothing. Fourier filtering preserving one to four harmonics (H), truncated curve Fourier filtering, and third degree polynomial curve fitting. Each filter's ability to recover, with fidelity, systolic and diastolic function parameters was evaluated under increasingly 'noisy' conditions and at several sampling rates. Third degree polynomial curve fittings and truncated Fourier filters exhibited very high sensitivity to noise. Three and five point time smoothing had moderate sensitivity to noise, but were highly affected by sampling rate. Fourier filtering preserving 2H or 3H produced the best compromise with high resilience to noise and independence of sampling rate as far as the recovery of these functional parameters is concerned. (author)

New method of safety assessment for pressure vessel of nuclear power plant--brief introduction of master curve approach

International Nuclear Information System (INIS)

Yang Wendou

2011-01-01

The new Master Curve Method is called as a revolutionary advance to the assessment of- reactor pressure vessel integrity in USA. This paper explains the origin, basis and standard of the Master Curve from the reactor pressure-temperature limit curve which assures the safety of nuclear power plant. According to the characteristics of brittle fracture which is greatly susceptible to the microstructure, the theory and the test method of the Master Curve as well as its statistical law which can be modeled using Weibull distribution are described in this paper. The meaning, advantage, application and importance of the Master Curve as well as the relation between the Master Curve and nuclear power safety are understood from the fitting formula for the fracture toughness database by Weibull distribution model. (author)

Exploration of variations in positions of upper and lower incisors, overjet, overbite, and irregularity index in orthodontic patients with dissimilar depths of curve of spee

International Nuclear Information System (INIS)

Kumari, N.; Fida, M.; Shaikh, A.

2017-01-01

The position and arrangement of teeth as well as the entire scheme of occlusion differs from one individual to the other .The purpose of this study was to examine differences in position and inclination of incisors, overjet, overbite and lower arch crowding in subjects with different depths of curve of Spee and to determine correlations between depth of curve of Spee and these variables. Methods: The sample comprised of 114 patients (55 females and 59 males) with fully erupted permanent second molars (age 12-25 years), having no history of previous orthodontic treatment, no craniofacial anomalies, and no missing permanent teeth. Study parameters were assessed by using pretreatment lateral cephalograms and dental casts of orthodontic patients. The entire sample was divided into three groups according to depth of curve of Spee (mild Spee=38, moderate Spee=38, severe Spee=38). Descriptive statistics were calculated. Differences between the Spee groups were assessed by analysis of variance. In addition, correlation coefficients were calculated between curve of Spee and other parameters. Results: Statistically significant differences were found in upper incisor inclination (p=0.000), lower incisor inclination (p=0.003), Steiner's mandibular plane angle (p=0.000), overjet (p=0.001), overbite (p=0.000) and irregularity index (p=0.008) among the Spee groups. Moreover, statistically significant positive correlations were found between curve of Spee and overjet, overbite and irregularity index. Upper and lower incisor inclinations as well as mandibular plane angle were found to have statistically significant but negative correlations with curve of Spee. Conclusion: Overjet and overbite in severe Spee group are larger than in mild and moderate Spee groups. There is negative correlation between curve of Spee depth and inclinations of upper and lower incisors. There is positive correlation between curve of Spee depth and severity of lower anterior crowding and Steiner

Technological change in energy systems. Learning curves, logistic curves and input-output coefficients

International Nuclear Information System (INIS)

Pan, Haoran; Koehler, Jonathan

2007-01-01

Learning curves have recently been widely adopted in climate-economy models to incorporate endogenous change of energy technologies, replacing the conventional assumption of an autonomous energy efficiency improvement. However, there has been little consideration of the credibility of the learning curve. The current trend that many important energy and climate change policy analyses rely on the learning curve means that it is of great importance to critically examine the basis for learning curves. Here, we analyse the use of learning curves in energy technology, usually implemented as a simple power function. We find that the learning curve cannot separate the effects of price and technological change, cannot reflect continuous and qualitative change of both conventional and emerging energy technologies, cannot help to determine the time paths of technological investment, and misses the central role of R and D activity in driving technological change. We argue that a logistic curve of improving performance modified to include R and D activity as a driving variable can better describe the cost reductions in energy technologies. Furthermore, we demonstrate that the top-down Leontief technology can incorporate the bottom-up technologies that improve along either the learning curve or the logistic curve, through changing input-output coefficients. An application to UK wind power illustrates that the logistic curve fits the observed data better and implies greater potential for cost reduction than the learning curve does. (author)

IMAGING STARSPOT EVOLUTION ON KEPLER TARGET KIC 5110407 USING LIGHT-CURVE INVERSION

International Nuclear Information System (INIS)

Roettenbacher, Rachael M.; Monnier, John D.; Harmon, Robert O.; Barclay, Thomas; Still, Martin

2013-01-01

The Kepler target KIC 5110407, a K-type star, shows strong quasi-periodic light curve fluctuations likely arising from the formation and decay of spots on the stellar surface rotating with a period of 3.4693 days. Using an established light-curve inversion algorithm, we study the evolution of the surface features based on Kepler space telescope light curves over a period of two years (with a gap of .25 years). At virtually all epochs, we detect at least one large spot group on the surface causing a 1%-10% flux modulation in the Kepler passband. By identifying and tracking spot groups over a range of inferred latitudes, we measured the surface differential rotation to be much smaller than that found for the Sun. We also searched for a correlation between the 17 stellar flares that occurred during our observations and the orientation of the dominant surface spot at the time of each flare. No statistically significant correlation was found except perhaps for the very brightest flares, suggesting that most flares are associated with regions devoid of spots or spots too small to be clearly discerned using our reconstruction technique. While we may see hints of long-term changes in the spot characteristics and flare statistics within our current data set, a longer baseline of observation will be needed to detect the existence of a magnetic cycle in KIC 5110407.

The self-regulation of motivation: Motivational strategies as mediator between motivational beliefs and engagement for learning.

NARCIS (Netherlands)

Smit, Karin; De Brabander, Cornelis; Boekaerts, Monique; Martens, Rob

2017-01-01

In this research we studied students´ motivational self-regulation as mediator between motivational beliefs and motivational outcomes. Dutch students in pre-vocational secondary education (N=3602, mean age 14) completed a questionnaire on five motivational strategies (Environmental Control,

The experience curve, option value, and the energy paradox

International Nuclear Information System (INIS)

Ansar, Jasmin; Sparks, Roger

2009-01-01

This paper develops a model to explain the 'energy paradox,' the inclination of households and firms to require very high internal rates of return in order to make energy-saving investments. The model abstracts from many features of such investments to focus on their irreversibility, the uncertainty of their future payoff streams, and the investor's anticipation of future technological advance. In this setting, the decision to invest in energy-saving technology can be delayed, providing option value. In addition, delay allows the potential investor to cash in on future experience-curve effects: With the passage of time, firms gain practical knowledge in producing and installing the energy-saving technology, enabling them to reduce the technology's up-front cost per unit of energy saved. We incorporate these fundamentals into a stochastic model where the investment's discounted benefits follow geometric Brownian motion. To demonstrate the model's capabilities, we generate simulation results for photovoltaic systems that highlight the experience-curve effect as a fundamental reason why households and firms delay making energy-saving investments until internal rates of return exceed values of 50% and higher, consistent with observations in the economics literature. We also explore altruistic motivations for energy conservation and the model's implications for both 'additionality' and the design of energy-conservation policy

The Effect of Motivational Practices on Volunteer Motivation to ...

African Journals Online (AJOL)

The study assesses whether organizations' motivational practices affect volunteer motivation and levels of performance. This study was guided by the following two research questions: first, what motivation practices exist in Volunteer Involving Organizations and whether such affect volunteers' motivation to volunteer again?

Investigation on Motorcyclist Riding Behaviour at Curve Entry Using Instrumented Motorcycle

Science.gov (United States)

Yuen, Choon Wah; Karim, Mohamed Rehan; Saifizul, Ahmad

2014-01-01

This paper details the study on the changes in riding behaviour, such as changes in speed as well as the brake force and throttle force applied, when motorcyclists ride over a curve section road using an instrumented motorcycle. In this study, an instrumented motorcycle equipped with various types of sensors, on-board cameras, and data loggers, was developed in order to collect the riding data on the study site. Results from the statistical analysis showed that riding characteristics, such as changes in speed, brake force, and throttle force applied, are influenced by the distance from the curve entry, riding experience, and travel mileage of the riders. A structural equation modeling was used to study the impact of these variables on the change of riding behaviour in curve entry section. Four regression equations are formed to study the relationship between four dependent variables, which are speed, throttle force, front brake force, and rear brake force applied with the independent variables. PMID:24523660

Math grades and intrinsic motivation in elementary school: A longitudinal investigation of their association.

Science.gov (United States)

Weidinger, Anne F; Steinmayr, Ricarda; Spinath, Birgit

2017-06-01

It is often argued that the negative development of intrinsic motivation in elementary school strongly depends on the presence of school grades because grades represent extrinsic consequences and achievement feedback that are supposed to influence intrinsically motivated behaviour. However, only a few studies have tested this hypothesis. Therefore, we investigated the role of school grades in inter- and intra-individual changes in elementary school students' intrinsic motivation from when grades were first introduced until the end of elementary school, when students in Germany receive recommendations for a secondary school type on the basis of their prior performance in school. A sample of 542 German elementary school students (t 1 : M = 7.95 years, SD = 0.57) was followed for 2 years from the end of Grade 2 to the end of Grade 4. At seven measurement occasions, children's math grades and their domain-specific intrinsic motivation were assessed. Latent growth curve models showed differences in trajectories of intrinsic motivation across students rather than uniform development. Moreover, students' trajectories of grades and intrinsic motivation were only weakly associated. A latent cross-lagged model revealed that reciprocal effects between the two constructs over time were small at best. Contrary to theoretical considerations, our results indicate that negative performance feedback in the form of grades does not necessarily lead to a decrease in intrinsic motivation. This calls into question the common opinion that a perception of being less competent, as reflected by poor grades, is responsible for weakening students' intrinsic motivation. © 2017 The British Psychological Society.

Assessment the effect of the CBT on motivation of the nursing students

Directory of Open Access Journals (Sweden)

Tayebeh Mehrabi

2016-01-01

Full Text Available Background: Motivation to academic achievement is critical for students of medical sciences, particularly nursing students. It is directly related to high levels of achievement and quality of life. Accordingly, diminished motivation would result in academic decline, study and work desertion and exhaustion. Therefore, this study aimed to investigate the effect of cognitive behavioural intervention on the motivation for academic achievement of the nursing students. Materials and Methods: This study was conducted on 64 female nursing students who were recruited to study based on the inclusion criteria. After sampling, the subjects were randomly assigned to study and control groups. Then, cognitive behavioural intervention was administered in study group during 60 days. Academic motivation scale was filled before, after and one month after the intervention. Data were analyzed by descriptive and inferential statistical tests (Chi-square, t-test. Results: After the intervention, mean scores of academic motivation were significantly increased in study group, compared to control group (P < 0.001. Comparison of the mean scores of academic motivation in two groups revealed a significant increase in mean score of academic motivation 151.50 (20.22 after cognitive behavioural intervention (P < 0.001. Conclusions: The findings suggested that cognitive behavioural intervention was a valuable psychotherapy technique to improve academic achievement motivation among nursing students.

Public Service Motivation and Monetary Incentives: Substitutes or Motivation Crowding?

DEFF Research Database (Denmark)

Jacobsen, Christian Bøtcher

2011-01-01

Motivation is probably one of the most important determinants for organizational performance, because it stimulates effort and effective behaviors among people in the organization. But what type of motivation should public managers rely on? The PSM literature has argued that public service...... motivation is the most important type of motivation in the delivery of public service, because it substitutes for egoistic motivation. Organizations whose members have high levels of PSM are therefore expected to be less dependent on utilitarian motivators such as monetary incentives. Motivation crowding...... theory, on the other hand, argues that the relationship is opposite, so it is the degree of incentives that affects motivation. Both arguments lead to expectations of an association between public service motivation and monetary incentives, but so far this complex relationship has not been entangled...

Assessment of mental workload and academic motivation in medical students.

Science.gov (United States)

Atalay, Kumru Didem; Can, Gulin Feryal; Erdem, Saban Remzi; Muderrisoglu, Ibrahim Haldun

2016-05-01

To investigate the level of correlation and direction of linearity between academic motivation and subjective workload. The study was conducted at Baskent University School of Medicine, Ankara, Turkey, from December 2013 to February 2014, and comprised Phase 5 Phase 6 medical students. Subjective workload level was determined by using National Aeronautics and Space Administration Task Load Index scale that was adapted to Turkish. Academic motivation values were obtained with the help of Academic Motivation Scale university form. SPSS 17 was used for statistical analysis. Of the total 105 subjects, 65(62%) students were in Phase 5 and 40(38%) were in Phase 6. Of the Phase 5 students, 18(27.7%) were boys and 47(72.3%) were girls, while of the Phase 6 students, 16(40%) were boys and 24(60%) were girls. There were significant differences in Phase 5 and Phase 6 students for mental effort (p=0.00) and physical effort (p=0.00). The highest correlation in Phase 5 was between mental effort and intrinsic motivation (r=0.343). For Phase 6, highest correlation was between effort and amotivation (r= -0.375). Subjective workload affected academic motivation in medical students.

Secondary eclipses in the CoRoT light curves

Directory of Open Access Journals (Sweden)

Belmonte Juan Antonio

2013-04-01

Full Text Available We identify and characterize secondary eclipses in the original light curves of published CoRoT planets using uniform detection and evaluation criteria. Our analysis is based on a Bayesian statistics: the eclipse search is carried out using Bayesian model selection, and the characterization of the plausible eclipse candidates using Bayesian parameter estimation. We discover statistically significant eclipse events for two planets, CoRoT-6b and CoRoT-11b, and for one brown dwarf, CoRoT-15b. We also find marginally significant eclipse events passing our plausibility criteria for CoRoT-3b, 13b, 18b, and 21b, and confirm the previously published CoRoT-1b and CoRoT-2b eclipses.

On the analysis of Canadian Holstein dairy cow lactation curves using standard growth functions.

Science.gov (United States)

López, S; France, J; Odongo, N E; McBride, R A; Kebreab, E; AlZahal, O; McBride, B W; Dijkstra, J

2015-04-01

Six classical growth functions (monomolecular, Schumacher, Gompertz, logistic, Richards, and Morgan) were fitted to individual and average (by parity) cumulative milk production curves of Canadian Holstein dairy cows. The data analyzed consisted of approximately 91,000 daily milk yield records corresponding to 122 first, 99 second, and 92 third parity individual lactation curves. The functions were fitted using nonlinear regression procedures, and their performance was assessed using goodness-of-fit statistics (coefficient of determination, residual mean squares, Akaike information criterion, and the correlation and concordance coefficients between observed and adjusted milk yields at several days in milk). Overall, all the growth functions evaluated showed an acceptable fit to the cumulative milk production curves, with the Richards equation ranking first (smallest Akaike information criterion) followed by the Morgan equation. Differences among the functions in their goodness-of-fit were enlarged when fitted to average curves by parity, where the sigmoidal functions with a variable point of inflection (Richards and Morgan) outperformed the other 4 equations. All the functions provided satisfactory predictions of milk yield (calculated from the first derivative of the functions) at different lactation stages, from early to late lactation. The Richards and Morgan equations provided the most accurate estimates of peak yield and total milk production per 305-d lactation, whereas the least accurate estimates were obtained with the logistic equation. In conclusion, classical growth functions (especially sigmoidal functions with a variable point of inflection) proved to be feasible alternatives to fit cumulative milk production curves of dairy cows, resulting in suitable statistical performance and accurate estimates of lactation traits. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Numerical modeling of the effect of surface topology on the saturated pool nucleate boiling curve

International Nuclear Information System (INIS)

Unal, C.; Pasamehmetoglu, K.O.

1993-01-01

A numerical study of saturated pool nucleate boiling with an emphasis on the effect of surface topography is presented. The numerical model consisted of solving the three-dimensional transient heat conduction equation within the heater subjected to nucleate boiling over its upper surface. The surface topography model considered the distribution of the cavity and cavity angles based on exponential and normal probability functions. Parametric results showed that the saturated nucleate boiling curve shifted left and became steeper with an increase in the mean cavity radius. The boiling curve was found to be sensitive to the selection of how many cavities were selected for each octagonal cell. A small variation in the statistical parameters, especially cavity radii for smooth surfaces, resulted in noticeable differences in wall superheat for a given heat flux. This result indicated that while the heat transfer coefficient increased with cavity radii, the cavity radii or height alone was not sufficient to characterize the boiling curve. It also suggested that statistical experimental data should consider large samples to characterize the surface topology. The boiling curve shifted to the right when the cavity angle was obtained using a normal distribution. This effect became less important when the number of cavities for each cell was increasing because the probability of the potential cavity with a larger radius in each cell was increased. When the contact angle of the fluid decreased for a given mean cavity radii, the boiling curve shifted to the right. This shift was more pronounced at smaller mean cavity radii and decreased with increasing mean cavity radii

Learning curve estimation techniques for the nuclear industry

International Nuclear Information System (INIS)

Vaurio, J.K.

1983-01-01

Statistical techniques are developed to estimate the progress made by the nuclear industry in learning to prevent accidents. Learning curves are derived for accident occurrence rates based on actuarial data, predictions are made for the future, and compact analytical equations are obtained for the statistical accuracies of the estimates. Both maximum likelihood estimation and the method of moments are applied to obtain parameters for the learning models, and results are compared to each other and to earlier graphical and analytical results. An effective statistical test is also derived to assess the significance of trends. The models used associate learning directly to accidents, to the number of plants and to the cumulative number of operating years. Using as a data base nine core damage accidents in electricity-producing plants, it is estimated that the probability of a plant to have a serious flaw has decreased from 0.1 to 0.01 during the developmental phase of the nuclear industry. At the same time the frequency of accidents has decreased from 0.04 per reactor year to 0.0004 per reactor year

Local Finite Density Theory, Statistical Blocking and Color Superconductivity

OpenAIRE

Ying, S.

2000-01-01

The motivation for the development of a local finite density theory is discussed. One of the problems related to an instability in the baryon number fluctuation of the chiral symmetry breaking phase of the quark system in the local theory is shown to exist. Such an instability problem is removed by taking into account the statistical blocking effects for the quark propagator, which depends on a macroscopic {\\em statistical blocking parameter} $\\epsilon$. This new frame work is then applied to...

On Nonextensive Statistics, Chaos and Fractal Strings

CERN Document Server

Castro, C

2004-01-01

Motivated by the growing evidence of universality and chaos in QFT and string theory, we study the Tsallis non-extensive statistics ( with a non-additive $ q$-entropy ) of an ensemble of fractal strings and branes of different dimensionalities. Non-equilibrium systems with complex dynamics in stationary states may exhibit large fluctuations of intensive quantities which are described in terms of generalized statistics. Tsallis statistics is a particular representative of such class. The non-extensive entropy and probability distribution of a canonical ensemble of fractal strings and branes is studied in terms of their dimensional spectrum which leads to a natural upper cutoff in energy and establishes a direct correlation among dimensions, energy and temperature. The absolute zero temperature ( Kelvin ) corresponds to zero dimensions (energy ) and an infinite temperature corresponds to infinite dimensions. In the concluding remarks some applications of fractal statistics, quasi-particles, knot theory, quantum...

Construction of estimated flow- and load-duration curves for Kentucky using the Water Availability Tool for Environmental Resources (WATER)

Science.gov (United States)

Unthank, Michael D.; Newson, Jeremy K.; Williamson, Tanja N.; Nelson, Hugh L.

2012-01-01

Flow- and load-duration curves were constructed from the model outputs of the U.S. Geological Survey's Water Availability Tool for Environmental Resources (WATER) application for streams in Kentucky. The WATER application was designed to access multiple geospatial datasets to generate more than 60 years of statistically based streamflow data for Kentucky. The WATER application enables a user to graphically select a site on a stream and generate an estimated hydrograph and flow-duration curve for the watershed upstream of that point. The flow-duration curves are constructed by calculating the exceedance probability of the modeled daily streamflows. User-defined water-quality criteria and (or) sampling results can be loaded into the WATER application to construct load-duration curves that are based on the modeled streamflow results. Estimates of flow and streamflow statistics were derived from TOPographically Based Hydrological MODEL (TOPMODEL) simulations in the WATER application. A modified TOPMODEL code, SDP-TOPMODEL (Sinkhole Drainage Process-TOPMODEL) was used to simulate daily mean discharges over the period of record for 5 karst and 5 non-karst watersheds in Kentucky in order to verify the calibrated model. A statistical evaluation of the model's verification simulations show that calibration criteria, established by previous WATER application reports, were met thus insuring the model's ability to provide acceptably accurate estimates of discharge at gaged and ungaged sites throughout Kentucky. Flow-duration curves are constructed in the WATER application by calculating the exceedence probability of the modeled daily flow values. The flow-duration intervals are expressed as a percentage, with zero corresponding to the highest stream discharge in the streamflow record. Load-duration curves are constructed by applying the loading equation (Load = Flow*Water-quality criterion) at each flow interval.

Statistical shape analysis with applications in R

CERN Document Server

Dryden, Ian L

2016-01-01

A thoroughly revised and updated edition of this introduction to modern statistical methods for shape analysis Shape analysis is an important tool in the many disciplines where objects are compared using geometrical features. Examples include comparing brain shape in schizophrenia; investigating protein molecules in bioinformatics; and describing growth of organisms in biology. This book is a significant update of the highly-regarded `Statistical Shape Analysis’ by the same authors. The new edition lays the foundations of landmark shape analysis, including geometrical concepts and statistical techniques, and extends to include analysis of curves, surfaces, images and other types of object data. Key definitions and concepts are discussed throughout, and the relative merits of different approaches are presented. The authors have included substantial new material on recent statistical developments and offer numerous examples throughout the text. Concepts are introduced in an accessible manner, while reta...

In vivo Comet assay – statistical analysis and power calculations of mice testicular cells

DEFF Research Database (Denmark)

Hansen, Merete Kjær; Sharma, Anoop Kumar; Dybdahl, Marianne

2014-01-01

is to provide curves for this statistic outlining the number of animals and gels to use. The current study was based on 11 compounds administered via oral gavage in three doses to male mice: CAS no. 110-26-9, CAS no. 512-56-1, CAS no. 111873-33-7, CAS no. 79-94-7, CAS no. 115-96-8, CAS no. 598-55-0, CAS no. 636....... A linear mixed-effects model was fitted to the summarized data and the estimated variance components were used to generate power curves as a function of sample size. The statistic that most appropriately summarized the within-sample distributions was the median of the log-transformed data, as it most...... consistently conformed to the assumptions of the statistical model. Power curves for 1.5-, 2-, and 2.5-fold changes of the highest dose group compared to the control group when 50 and 100 cells were scored per gel are provided to aid in the design of future Comet assay studies on testicular cells....

Computerised curve deconvolution of TL/OSL curves using a popular spreadsheet program.

Science.gov (United States)

Afouxenidis, D; Polymeris, G S; Tsirliganis, N C; Kitis, G

2012-05-01

This paper exploits the possibility of using commercial software for thermoluminescence and optically stimulated luminescence curve deconvolution analysis. The widely used software package Microsoft Excel, with the Solver utility has been used to perform deconvolution analysis to both experimental and reference glow curves resulted from the GLOw Curve ANalysis INtercomparison project. The simple interface of this programme combined with the powerful Solver utility, allows the analysis of complex stimulated luminescence curves into their components and the evaluation of the associated luminescence parameters.

Computerised curve deconvolution of TL/OSL curves using a popular spreadsheet program

International Nuclear Information System (INIS)

Afouxenidis, D.; Polymeris, G. S.; Tsirliganis, N. C.; Kitis, G.

2012-01-01

This paper exploits the possibility of using commercial software for thermoluminescence and optically stimulated luminescence curve deconvolution analysis. The widely used software package Microsoft Excel, with the Solver utility has been used to perform deconvolution analysis to both experimental and reference glow curves resulted from the Glow Curve Analysis Intercomparison project. The simple interface of this programme combined with the powerful Solver utility, allows the analysis of complex stimulated luminescence curves into their components and the evaluation of the associated luminescence parameters. (authors)

Organizational commitment and intrinsic motivation of regular and contractual primary health care providers

Directory of Open Access Journals (Sweden)

Pawan Kumar

2016-01-01

Full Text Available Background: Motivated and committed employees deliver better health care, which results in better outcomes and higher patient satisfaction. Objective: To assess the Organizational Commitment and Intrinsic Motivation of Primary Health Care Providers (HCPs in New Delhi, India. Materials and Methods: Study was conducted in 2013 on a sample of 333 HCPs who were selected using multistage stage random sampling technique. The sample includes medical officers, auxiliary nurses and midwives, and pharmacists and laboratory technicians/assistants among regular and contractual staff. Data were collected using the pretested structured questionnaire for organization commitment (OC, job satisfiers, and intrinsic job motivation. Analysis was done by using SPSS version 18 and appropriate statistical tests were applied. Results: The mean score for OC for entire regular staff is 1.6 ± 0.39 and contractual staff is 1.3 ± 0.45 which has statistically significant difference (t = 5.57; P = 0.00. In both regular and contractual staff, none of them show high emotional attachment with the organization and does not feel part of the family in the organization. Contractual staff does not feel proud to work in a present organization for rest of their career. Intrinsic motivation is high in both regular and contractual groups but intergroup difference is significant (t = 2.38; P < 0.05. Contractual staff has more dissatisfier than regular, and the difference is significant (P < 0.01. Conclusion: Organizational commitment and intrinsic motivation of contractual staff are lesser than the permanent staff. Appropriate changes are required in the predictors of organizational commitment and factors responsible for satisfaction in the organization to keep the contractual human resource motivated and committed to the organization.

Effects of different premature chromosome condensation method on dose-curve of 60Co γ-ray

International Nuclear Information System (INIS)

Guo Yicao; Yang Haoxian; Yang Yuhua; Li Xi'na; Huang Weixu; Zheng Qiaoling

2012-01-01

Objective: To study the effect of traditional method and improved method of the premature chromosome condensation (PCC) on the dose-effect curve of 60 Co γ ray, for choosing the rapid and accurate biological dose estimating method for the accident emergency. Methods: Collected 3 healthy male cubits venous blood (23 to 28 years old), and irradiated by 0, 1.0, 5.0, 10.0, 15.0, 20.0 Gy 60 Co γ ray (absorbed dose rate: 0.635 Gy/min). Observed the relation of dose-effect curve in the 2 incubation time (50 hours and 60 hours) of the traditional method and improved method. Used the dose-effect curve to verify the exposure of 10.0 Gy (absorbed dose rate: 0.670 Gy/min). Results: (1) In the traditional method of 50-hour culture, the PCC cell count in 15.0 Gy and 20.0 Gy was of no statistical significance. But there were statistical significance in the traditional method of 60-hours culture and improved method (50-hour culture and 60-hour culture). Used the last 3 culture methods to make dose curve. (2) In the above 3 culture methods, the related coefficient between PCC ring and exposure dose was quite close (all of more than 0.996, P 0.05), the morphology of regression straight lines almost overlap. (3) Used the above 3 dose-effect curves to estimate the irradiation results (10.0 Gy), the error was less than or equal to 8%, all of them were within the allowable range of the biological experiment (15%). Conclusion: The 3 dose-effect curves of the above 3 culture methods can apply to biological dose estimating of large doses of ionizing radiation damage. Especially the improved method of 50-hour culture,it is much faster to estimate and it should be regarded as the first choice in accident emergency. (authors)

Enhanced secondary analysis of survival data: reconstructing the data from published Kaplan-Meier survival curves

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Guyot Patricia

2012-02-01

Full Text Available Abstract Background The results of Randomized Controlled Trials (RCTs on time-to-event outcomes that are usually reported are median time to events and Cox Hazard Ratio. These do not constitute the sufficient statistics required for meta-analysis or cost-effectiveness analysis, and their use in secondary analyses requires strong assumptions that may not have been adequately tested. In order to enhance the quality of secondary data analyses, we propose a method which derives from the published Kaplan Meier survival curves a close approximation to the original individual patient time-to-event data from which they were generated. Methods We develop an algorithm that maps from digitised curves back to KM data by finding numerical solutions to the inverted KM equations, using where available information on number of events and numbers at risk. The reproducibility and accuracy of survival probabilities, median survival times and hazard ratios based on reconstructed KM data was assessed by comparing published statistics (survival probabilities, medians and hazard ratios with statistics based on repeated reconstructions by multiple observers. Results The validation exercise established there was no material systematic error and that there was a high degree of reproducibility for all statistics. Accuracy was excellent for survival probabilities and medians, for hazard ratios reasonable accuracy can only be obtained if at least numbers at risk or total number of events are reported. Conclusion The algorithm is a reliable tool for meta-analysis and cost-effectiveness analyses of RCTs reporting time-to-event data. It is recommended that all RCTs should report information on numbers at risk and total number of events alongside KM curves.

A Preliminary Study of Classroom Motivators and De-Motivators from a Motivation-Hygiene Perspective

Science.gov (United States)

Katt, James A.; Condly, Steven J.

2009-01-01

This study seeks to begin answering two simple questions: "What motivates our students?" and its corollary, "What prevents our students from being motivated?" The motivation-hygiene theory (F. Herzberg, "Work and the nature of man," World Publishing, Cleveland, OH, 1966), a well-tested theory from organizational…

Motivated Explanation

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Richard ePatterson

2015-10-01

Full Text Available Although motivation is a well-established field of study in its own right, and has been fruitfully studied in connection with attribution theory and belief formation under the heading of motivated thinking, its powerful and pervasive influence on explanatory processes is less well explored. Where one has a strong motivation to understand some event correctly, one is thereby motivated to adhere as best one can to normative or epistemic criteria for correct or accurate explanation, even if one does not consciously formulate or apply such criteria. By contrast, many of our motivations to explain introduce bias into the processes involved in generating, evaluating, or giving of explanations. Non-epistemic explanatory motivations, or (following Kunda’s usage, directional motivations, include self-justification, resolution of cognitive dissonance, deliberate deception, teaching, and many more. Some of these motivations lead to the relaxation or violation of epistemic norms, combined with an effort to preserve the appearance of accuracy; others enhance epistemic motivation, so that one engages in more careful and thorough generational and evaluative processes. In short, real life explanatory processes are often constrained by multiple goals, epistemic and directional, where these goals may mutually reinforce one another or may conflict, and where our explanations emerge as a matter of weighing and satisfying those goals. Our proposals are largely programmatic, although we do review a good deal of relevant behavioral and neurological evidence. Specifically, we recognize five generative processes, some of which cover further sub-processes, and six evaluative processes. All of these are potential points of entry for the influence of motivation. We then suggest in some detail how specific sorts of explanatory motivation interact with specific explanatory processes.

Radioligand assays - methods and applications. IV. Uniform regression of hyperbolic and linear radioimmunoassay calibration curves

Energy Technology Data Exchange (ETDEWEB)

Keilacker, H; Becker, G; Ziegler, M; Gottschling, H D [Zentralinstitut fuer Diabetes, Karlsburg (German Democratic Republic)

1980-10-01

In order to handle all types of radioimmunoassay (RIA) calibration curves obtained in the authors' laboratory in the same way, they tried to find a non-linear expression for their regression which allows calibration curves with different degrees of curvature to be fitted. Considering the two boundary cases of the incubation protocol they derived a hyperbolic inverse regression function: x = a/sub 1/y + a/sub 0/ + asub(-1)y/sup -1/, where x is the total concentration of antigen, asub(i) are constants, and y is the specifically bound radioactivity. An RIA evaluation procedure based on this function is described providing a fitted inverse RIA calibration curve and some statistical quality parameters. The latter are of an order which is normal for RIA systems. There is an excellent agreement between fitted and experimentally obtained calibration curves having a different degree of curvature.

Generational motivation and preference for reward and recognition

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Nico Martins

2015-08-01

Full Text Available Generation sub-groups have been and continue to be stereotyped as requiring different approaches in the workplace and elsewhere with regard to what keeps them motivated and satisfied. Two measuring instruments were distributed electronically to all staff of a South African Facilities Management firm. The one-way ANOVA was conducted with post-hoc tests to establish which factors display statistically significant differences between generations. The findings demonstrated that certain generation sub-groups have preferences for different types of reward, reward categories, and have different perceptions about what types of reward attracts, motivates and retains employees. The main recommendation is that the company needs to adopt a flexible approach to reward and recognition that allows employees to tailor their reward structure to their own needs

A prospective randomized comparison of curved array and radial echoendoscopy in patients with esophageal cancer

DEFF Research Database (Denmark)

Siemsen, Mette; Svendsen, Lars Bo; Knigge, Ulrich

2003-01-01

BACKGROUND: Both curved array and radial scanning echoendoscopy are used for locoregional staging of cancer arising in the esophagus or cardia. The accuracy of TNM staging of these malignancies by curved array and radial EUS was compared in a prospective, randomized study. METHODS: Patients...... with cancer of the esophagus or cardia were examined by both curved array and radial echoendoscopy in randomized order by the same endosonographer in an unblinded fashion. The staging results and the examination time for the two echoendoscopies were compared and statistically analyzed, and finally compared......, respectively, 15 and 12 minutes (pcancer of the esophagus or cardia. The choice of echoendoscope for TNM staging in patients with these malignancies is, therefore, a question...

[Team motivation and motivational strategies adopted by nurses].

Science.gov (United States)

Bezerra, Felipa Daiana; Andrade, Marta Francisca da Conceição; Andrade, Joseilze Santos de; Vieira, Maria Jésia; Pimentel, Deborah

2010-01-01

Qualitative study held in an emergency hospital in Aracaju-SE, which aimed to know the perception of nurses about what is a motivated nursing team, to identify possible motivational policies used by them and if they are consistent with the policies proposed by Frederick Herzberg in his theory. Of the 20 nurses participants, the most understood the motivation as a set of techniques possible to shape the behavior of the individual at work, linking it to extrinsic factors and 60% did not consider his team motivated. The types of motivational policies that usually apply realized that these correspond to intrinsic factors aimed at self recovery and self realization of individuals in the tasks running.

Working females : a modern statistical approach

OpenAIRE

Kuhlenkasper, Torben

2010-01-01

The thesis analyzes the changing employment and economic situation of females when they become mothers. Two major questions are focused in the thesis: First, when do mothers return to their previous employment after bearing a child? Secondly, what are the individual economic consequences after having returned to the labor market? Both questions are analyzed empirically with latest statistical methods. The first major part of the thesis, corresponding to the above first motivated question, ...

Effectiveness of a Stress Management Training on Motivation and Well-being

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Saul Neves de Jesus

2013-09-01

Full Text Available This study investigated the immediate influence of a stress management training on teachers’ and physicians’ motivational (professional objective, intrinsic motivation, efficacy expectancies and well-being related outcomes (positive well-being, emotional exhaustion, work distress, irrational beliefs using meta-analytical techniques. In an action-research perspective, the stress management training program was implemented in several groups of physicians and teachers, in Portugal and in Brazil (n=144. It was found that, at all the samples where this intervention was implemented, an increase occurred on all motivational indicators and on positive well-being, and a decrease on negative well-being outcomes; nevertheless, not all obtained results are statistically significant. The largest impact of the implemented training program was at positive well-being at work, with a large effect size (d+=.81, and at the irrational beliefs, with a medium effect size (d+=.61. These results suggest the short-term benefits of this intervention on teachers’ and physicians’ motivation and well-being.

Calculation of accurate small angle X-ray scattering curves from coarse-grained protein models

DEFF Research Database (Denmark)

Stovgaard, Kasper; Andreetta, Christian; Ferkinghoff-Borg, Jesper

2010-01-01

, which is paramount for structure determination based on statistical inference. Results: We present a method for the efficient calculation of accurate SAXS curves based on the Debye formula and a set of scattering form factors for dummy atom representations of amino acids. Such a method avoids......DBN. This resulted in a significant improvement in the decoy recognition performance. In conclusion, the presented method shows great promise for use in statistical inference of protein structures from SAXS data....

High cycle fatigue test and regression methods of S-N curve

International Nuclear Information System (INIS)

Kim, D. W.; Park, J. Y.; Kim, W. G.; Yoon, J. H.

2011-11-01

The fatigue design curve in the ASME Boiler and Pressure Vessel Code Section III are based on the assumption that fatigue life is infinite after 106 cycles. This is because standard fatigue testing equipment prior to the past decades was limited in speed to less than 200 cycles per second. Traditional servo-hydraulic machines work at frequency of 50 Hz. Servo-hydraulic machines working at 1000 Hz have been developed after 1997. This machines allow high frequency and displacement of up to ±0.1 mm and dynamic load of ±20 kN are guaranteed. The frequency of resonant fatigue test machine is 50-250 Hz. Various forced vibration-based system works at 500 Hz or 1.8 kHz. Rotating bending machines allow testing frequency at 0.1-200 Hz. The main advantage of ultrasonic fatigue testing at 20 kHz is performing Although S-N curve is determined by experiment, the fatigue strength corresponding to a given fatigue life should be determined by statistical method considering the scatter of fatigue properties. In this report, the statistical methods for evaluation of fatigue test data is investigated

A course in statistics with R

CERN Document Server

Tattar, Prabhanjan N; Manjunath, B G

2016-01-01

Integrates the theory and applications of statistics using R A Course in Statistics with R has been written to bridge the gap between theory and applications and explain how mathematical expressions are converted into R programs. The book has been primarily designed as a useful companion for a Masters student during each semester of the course, but will also help applied statisticians in revisiting the underpinnings of the subject. With this dual goal in mind, the book begins with R basics and quickly covers visualization and exploratory analysis. Probability and statistical inference, inclusive of classical, nonparametric, and Bayesian schools, is developed with definitions, motivations, mathematical expression and R programs in a way which will help the reader to understand the mathematical development as well as R implementation. Linear regression models, experimental designs, multivariate analysis, and categorical data analysis are treated in a way which makes effective use of visualization techniques and...

Improving Accuracy and Temporal Resolution of Learning Curve Estimation for within- and across-Session Analysis

Science.gov (United States)

Tabelow, Karsten; König, Reinhard; Polzehl, Jörg

2016-01-01

Estimation of learning curves is ubiquitously based on proportions of correct responses within moving trial windows. Thereby, it is tacitly assumed that learning performance is constant within the moving windows, which, however, is often not the case. In the present study we demonstrate that violations of this assumption lead to systematic errors in the analysis of learning curves, and we explored the dependency of these errors on window size, different statistical models, and learning phase. To reduce these errors in the analysis of single-subject data as well as on the population level, we propose adequate statistical methods for the estimation of learning curves and the construction of confidence intervals, trial by trial. Applied to data from an avoidance learning experiment with rodents, these methods revealed performance changes occurring at multiple time scales within and across training sessions which were otherwise obscured in the conventional analysis. Our work shows that the proper assessment of the behavioral dynamics of learning at high temporal resolution can shed new light on specific learning processes, and, thus, allows to refine existing learning concepts. It further disambiguates the interpretation of neurophysiological signal changes recorded during training in relation to learning. PMID:27303809

Improving Accuracy and Temporal Resolution of Learning Curve Estimation for within- and across-Session Analysis.

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Matthias Deliano

Full Text Available Estimation of learning curves is ubiquitously based on proportions of correct responses within moving trial windows. Thereby, it is tacitly assumed that learning performance is constant within the moving windows, which, however, is often not the case. In the present study we demonstrate that violations of this assumption lead to systematic errors in the analysis of learning curves, and we explored the dependency of these errors on window size, different statistical models, and learning phase. To reduce these errors in the analysis of single-subject data as well as on the population level, we propose adequate statistical methods for the estimation of learning curves and the construction of confidence intervals, trial by trial. Applied to data from an avoidance learning experiment with rodents, these methods revealed performance changes occurring at multiple time scales within and across training sessions which were otherwise obscured in the conventional analysis. Our work shows that the proper assessment of the behavioral dynamics of learning at high temporal resolution can shed new light on specific learning processes, and, thus, allows to refine existing learning concepts. It further disambiguates the interpretation of neurophysiological signal changes recorded during training in relation to learning.

INTERPLAY OF DIFFERENT CONTEXTUAL MOTIVATIONS AND THEIR IMPLICATIONS FOR EXERCISE MOTIVATION

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David González-Cutre

2011-06-01

Full Text Available The aim of this study was to analyze the interaction between different contextual motivations and exercise motivation. The sample consisted of 449 exercisers aged between 16 and 53 years. Questionnaires were used to measure the satisfaction of basic psychological needs, self-determined motivation and the autotelic experience during exercise. The level of self-determined motivation regarding health, leisure and interpersonal relationships was also measured. The results of the structural equation modeling demonstrated that basic psychological needs and self-determined motivations about health and leisure positively predicted the self-determined motivation to exercise. Moreover, the self-determined motivation to exercise positively predicted the autotelic experience. The model was invariant across age, although some gender differences were found. Specifically, the self-determined motivation towards health in men did not significantly predict the self-determined motivation to exercise. These results represent to evaluate the role that other contextual motivations play in exercise motivation

Performance Motivation of Elite Athletes, Recreational Athletes and Non-Athletes

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Šmela Pavel

2017-11-01

Full Text Available The aim of the paper is to widen knowledge about motivation of elite, recreational athletes and non-athletes. Participants from the elite athletes group (n = 35, 16.7 ± .70 years old were football players of the Slovak national team. Recreational athletes (n = 31, 16.8 ± .80 years old and non-athletes (n = 29, 15.7 ± .60 years old are visiting Grammar School in Zvolen. D-M-V standardized questionnaire was used to determine performance motivation. The Kolmogorov-Smirnov's test disconfirmed the null hypothesis on the normality of data. We used the non-parametric Kruskal-Wallis and Mann-Whitney U tests to determine the statistical significance of the differences. The results showed that there were significant (p .0.01 differences with large effect size (η2 ≥ .14 in all the three (the performance motives scale, the anxiety inhibiting performance scale and the anxiety supporting performance scale dimensions among the research groups. The motivation of elite athletes is significantly higher (p = .048; r = .25 compared to the recreational athletes. Also, compared to the non-athletes, the level of performance motivation is significantly higher (p = .002; r = .51 in the elite athletes. Based on the results of the study we can formulate the statement that the level of performance motivation is contingent on the level of sport activity.

Motivation for pilgrimage: using theory to explore motivations

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Ruth Blackwell

2010-01-01

Full Text Available This article is a discussion of the motivations for pilgrimage and it will draw upon theories of motivation to explore the continuing attraction of pilgrimage in contemporary times. This discussion is located within the field of Event Management. Event Management is a fast growing discipline which focuses on the design, production and management of planned events, such as festivals, celebrations, conferences, fund-raisers and so on. Clearly pilgrimages, as planned events, fit into this definition. In this context, it is essential to recognise the importance of understanding the motives and needs of event customers so that we can plan to help our customers satisfy their motives. Whilst it might seem abhorrent and commercial to talk of pilgrims as customers, pilgrimages and religious sites have become more and more commodified and increasingly are deemed to need professional management. Key theories of motivation will be compared in order to identify the prime motivating factors underpinning people’s decisions to make pilgrimages.

Motivational Profiles and Motivation for Lifelong Learning of Medical Specialists.

Science.gov (United States)

van der Burgt, Stéphanie M E; Kusurkar, Rashmi A; Wilschut, Janneke A; Tjin A Tsoi, Sharon L N M; Croiset, Gerda; Peerdeman, Saskia M

2018-05-22

Medical specialists face the challenge of maintaining their knowledge and skills and continuing professional development, that is, lifelong learning. Motivation may play an integral role in many of the challenges facing the physician workforce today including maintenance of a high performance. The aim of this study was to determine whether medical specialists show different motivational profiles and if these profiles predict differences in motivation for lifelong learning. An online questionnaire was sent to every medical specialist working in five hospitals in the Netherlands. The questionnaire included the validated Multidimensional Work Motivation Scale and the Jefferson Scale of Physician Lifelong Learning together with background questions like age, gender, and type of hospital. Respondents were grouped into different motivational profiles by using a two-step clustering approach. Four motivational profiles were identified: (1) HAMC profile (for High Autonomous and Moderate Controlled motivation), (2) MAMC profile (for Moderate Autonomous and Moderate Controlled motivation), (3) MALC profile (for Moderate Autonomous and Low Controlled motivation), and (4) HALC profile (for High Autonomous and Low Controlled motivation). Most of the female specialists that work in an academic hospital and specialists with a surgical specialty were represented in the HALC profile. Four motivational profiles were found among medical specialists, differing in gender, experience and type of specialization. The profiles are based on the combination of autonomous motivation (AM) and controlled motivation (CM) in the specialists. The profiles that have a high score on autonomous motivation have a positive association with lifelong learning.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work

Self-Generated Motives for Not Gambling Among Young Adult Non-gamblers.

Science.gov (United States)

Rash, Christina L; McGrath, Daniel S

2017-09-01

Motivational models have been shown to usefully describe reasons for engaging in addictive behaviors including gambling disorder. Although most scales designed to measure motives have been derived statistically, self-generated open-ended responses have also shown utility for identifying unique motives for gambling. While the motivational structure for gambling disorder has been extensively explored, there has been a paucity of research examining motives for choosing not to gamble. This is not the case for other addictive behaviors such as alcohol use where motives for abstaining from drinking have been well defined. The primary goal of this study was to qualitatively explore and identify motives for not gambling in a sample of young adult non-gamblers using open-ended responses. A sample (N = 196) of undergraduate current non-gamblers, defined as no gambling activity over the previous 12 months, completed a series of questionnaires on demographics, gambling behavior, and alcohol consumption. Furthermore, they were asked to provide their top three reasons for not gambling in rank order. The results revealed eight specific motives for why participants chose not to gamble: 'financial reasons and risk aversion'; 'disinterest and other priorities'; 'personal and religious convictions'; 'addiction concerns'; 'influence of others' values'; 'awareness of the odds'; 'lack of access, opportunity, or skill'; and 'emotional distress'. Personal and religious convictions reasons were also related to lifetime non-drinking, suggesting that these motives are associated with decreased addictive behaviors in general. Ultimately, these results may help to inform the design of prevention strategies for gambling disorder.

Command and motivation

DEFF Research Database (Denmark)

Jacobsen, Christian Bøtcher; Hvidtved, Johan; Andersen, Lotte Bøgh

2014-01-01

Motivated employees are crucial to organizations, but external interventions such as command systems and financial incentives may decrease motivation. If these external interventions are perceived to be controlling, they are expected to crowd out intrinsic motivation, and this may also apply...... to other types of autonomous motivation such as public service motivation. The perception of external interventions is thus expected to be vital. This article investigates how the perception of a specific command system (obligatory student plans) is associated with intrinsic motivation and public service...... motivation. Using a dataset with 3,230 school teachers in Denmark, a structural equation model shows that the perception of obligatory student plans as controlling is negatively associated with all of the investigated types of employee motivation, supporting that motivation crowding can occur....

Employees motivation in two wood industry companies in Croatia

Directory of Open Access Journals (Sweden)

Denis Jelačić

2016-12-01

Full Text Available This research analysed the motivating and demotivating factors amongst employees in two wood processing companies in Croatia. Research was conducted over the year 2014 and 2015, during the economic recovery of the companies and Croatian economy in general. Research was conducted with a survey using a questionnaire containing six questions with multiple choice statements. The questions were closed-ended, and respondents used the Likert four-level scale of importance for each statement. A total of 180 employees were surveyed, and results were statistically processed by using the χ2 - test and cluster analysis. This study established that the motivation factors most important to employees between researched companies are significantly different. Employees were most concerned about social needs. Also, employees consider psychological circumstances of work to be very important. Employees’ overall motivation can be linked to higher efficiency and higher quality production and business results, and such research should be conducted more often.

The motivational value of rewards amongst Malawi’s health professionals

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Alfred W.D. Chanza

2013-08-01

Research purpose: This study focuses on assessing the motivational value of rewards amongst health professionals in Malawi’s Ministry of Health (MoH. Motivation for the study: Malawian studies indicate that Malawi’s MoH has become dysfunctional largely due to reward-related problems faced by its health professionals. Research design, approach and method: This study was a non-experimental design with an explanatory and evaluative approach, utilising both quantitative (questionnaire and qualitative methods (literature review, interviews and focus group discussions. Main findings: The study confirmed the existence of reward-related problems amongst health professionals in Malawi’s MoH. Initially, statistical testing of the hypothesised model collapsed, suggesting that no relationship existed amongst the variables. However, statistical testing of the re-specified model suggests that there is a positive relationship between financial and non-financial rewards. Through the structural equation modeling (SEM exercise, an inverse (negative relationship between financial and non-financial rewards was established. Practical/managerial implications: The re-specified model symbolises a pragmatic departure from theoretical claims that financial rewards (salaries or money in general are not a motivator. The graphic model suggests to managers and policy-makers that both financial and non-financial rewards are very important and valuable in any employment relationship. Contribution/value-add: An inverse (causal relationship between financial and non-financial rewards has been established, graphically demonstrated and scientifically explained.

Approximation by planar elastic curves

DEFF Research Database (Denmark)

Brander, David; Gravesen, Jens; Nørbjerg, Toke Bjerge

2016-01-01

We give an algorithm for approximating a given plane curve segment by a planar elastic curve. The method depends on an analytic representation of the space of elastic curve segments, together with a geometric method for obtaining a good initial guess for the approximating curve. A gradient......-driven optimization is then used to find the approximating elastic curve....

Stochastic geometry of critical curves, Schramm-Loewner evolutions and conformal field theory

International Nuclear Information System (INIS)

Gruzberg, Ilya A

2006-01-01

Conformally invariant curves that appear at critical points in two-dimensional statistical mechanics systems and their fractal geometry have received a lot of attention in recent years. On the one hand, Schramm (2000 Israel J. Math. 118 221 (Preprint math.PR/9904022)) has invented a new rigorous as well as practical calculational approach to critical curves, based on a beautiful unification of conformal maps and stochastic processes, and by now known as Schramm-Loewner evolution (SLE). On the other hand, Duplantier (2000 Phys. Rev. Lett. 84 1363; Fractal Geometry and Applications: A Jubilee of Benot Mandelbrot: Part 2 (Proc. Symp. Pure Math. vol 72) (Providence, RI: American Mathematical Society) p 365 (Preprint math-ph/0303034)) has applied boundary quantum gravity methods to calculate exact multifractal exponents associated with critical curves. In the first part of this paper, I provide a pedagogical introduction to SLE. I present mathematical facts from the theory of conformal maps and stochastic processes related to SLE. Then I review basic properties of SLE and provide practical derivation of various interesting quantities related to critical curves, including fractal dimensions and crossing probabilities. The second part of the paper is devoted to a way of describing critical curves using boundary conformal field theory (CFT) in the so-called Coulomb gas formalism. This description provides an alternative (to quantum gravity) way of obtaining the multifractal spectrum of critical curves using only traditional methods of CFT based on free bosonic fields

Analysis of self-determined motivation in basketball players through goal orientations.

Science.gov (United States)

Gómez-López, Manuel; Granero-Gallegos, Antonio; Abraldes, J Arturo; Rodríguez-Suárez, Nuria

2013-09-01

The purpose of this study was twofold. Firstly to examine the relations between the different constructs that defines Nicholls' Achievement Goal Theory and Deci and Ryan's self-determination theory. Secondly to analyse the differences that exist between them with respect to the socio-demographic variables gender and age. A sample of 292 federated basketball players from the Region of Murcia (Spain) with ages between 14 and 18 years old was used. In addition, Castilian versions of The Perception of Success Questionnaire (POSQ) and the Sports Motivational Scale (SMS) were administered. Three statistical analyses were employed, a descriptive analysis, a correlation analysis and a regression analysis. The results showed a positive relation between ego orientation, extrinsic motivation and amotivation. The motivational relations between both theories and the differences with respect to gender and age are discussed. We have found out that mainly gender and also age differences are strong predictors of ego orientation, extrinsic motivation of external regulation and amotivation. We can also confirm that extrinsic motivation of external regulation positively predicts ego orientation and a decrease of task orientation. The results ratify the use of the Spanish version of the SMS to measure different types of motivation within the sports context.

Statistical reporting inconsistencies in experimental philosophy.

Science.gov (United States)

Colombo, Matteo; Duev, Georgi; Nuijten, Michèle B; Sprenger, Jan

2018-01-01

Experimental philosophy (x-phi) is a young field of research in the intersection of philosophy and psychology. It aims to make progress on philosophical questions by using experimental methods traditionally associated with the psychological and behavioral sciences, such as null hypothesis significance testing (NHST). Motivated by recent discussions about a methodological crisis in the behavioral sciences, questions have been raised about the methodological standards of x-phi. Here, we focus on one aspect of this question, namely the rate of inconsistencies in statistical reporting. Previous research has examined the extent to which published articles in psychology and other behavioral sciences present statistical inconsistencies in reporting the results of NHST. In this study, we used the R package statcheck to detect statistical inconsistencies in x-phi, and compared rates of inconsistencies in psychology and philosophy. We found that rates of inconsistencies in x-phi are lower than in the psychological and behavioral sciences. From the point of view of statistical reporting consistency, x-phi seems to do no worse, and perhaps even better, than psychological science.

Statistical reporting inconsistencies in experimental philosophy

Science.gov (United States)

Colombo, Matteo; Duev, Georgi; Nuijten, Michèle B.; Sprenger, Jan

2018-01-01

Experimental philosophy (x-phi) is a young field of research in the intersection of philosophy and psychology. It aims to make progress on philosophical questions by using experimental methods traditionally associated with the psychological and behavioral sciences, such as null hypothesis significance testing (NHST). Motivated by recent discussions about a methodological crisis in the behavioral sciences, questions have been raised about the methodological standards of x-phi. Here, we focus on one aspect of this question, namely the rate of inconsistencies in statistical reporting. Previous research has examined the extent to which published articles in psychology and other behavioral sciences present statistical inconsistencies in reporting the results of NHST. In this study, we used the R package statcheck to detect statistical inconsistencies in x-phi, and compared rates of inconsistencies in psychology and philosophy. We found that rates of inconsistencies in x-phi are lower than in the psychological and behavioral sciences. From the point of view of statistical reporting consistency, x-phi seems to do no worse, and perhaps even better, than psychological science. PMID:29649220

A comparative study on undergraduate students' academic motivation and academic self-concept.

Science.gov (United States)

Isiksal, Mine

2010-11-01

The purpose of this study was to investigate Turkish and American undergraduate students' academic motivation and academic self-concept scores regarding the years that they spent in university. The analysis was based on 566 (284 Turkish, 282 American) undergraduate students where, Academic Motivation Scale and Academic Self-Concept Scale were used as measuring instruments. The results showed that there was a statistical significant effect of nationality and number of years spent in university on undergraduate students' intrinsic motivation, extrinsic motivation, and self-concept scores. Turkish students had higher intrinsic scores whereas American students had higher extrinsic scores and more positive academic-self concept compared to Turkish partners. Regarding grade level, senior students from both cultures had higher intrinsic motivation and academic self-concept scores compared to other grade levels. In terms of extrinsic motivation, there is steady decline in American students' scores as grade level increases. On the other hand, Turkish undergraduates' extrinsic scores decrease in the second year but increase in the third and fourth year of university education. Results were discussed by taking into consideration the social and cultural differences between two nations.

Assessment of the relationship between the engagement in leisure time and academic motivation among the students of faculty of education

OpenAIRE

SARI, Ihsan; CETIN, Mehmet; KAYA, Erdi; GULLE, Mahmut; KAHRAMANOĞLU, Recep

2014-01-01

The aim of the study was to determine the relationship between leisure time motivation and academic motivation among the students who studied at the Faculty of Education of Mustafa Kemal University. 260 students (Xyears: 21.29±2.11) constituted the sample of the study. For the analyses of the data; Leisure Motivation Scale and Academic Motivation Scale were employed. The data were analyzed using descriptive statistics, Pearson's correlation test and regression analysis. According to the ...

Addressing group dynamics in a brief motivational intervention for college student drinkers.

Science.gov (United States)

Faris, Alexander S; Brown, Janice M

2003-01-01

Previous research indicates that brief motivational interventions for college student drinkers may be less effective in group settings than individual settings. Social psychological theories about counterproductive group dynamics may partially explain this finding. The present study examined potential problems with group motivational interventions by comparing outcomes from a standard group motivational intervention (SGMI; n = 25), an enhanced group motivational intervention (EGMI; n = 27) designed to suppress counterproductive processes, and a no intervention control (n = 23). SGMI and EGMI participants reported disruptive group dynamics as evidenced by low elaboration likelihood, production blocking, and social loafing, though the level of disturbance was significantly lower for EGMI individuals (p = .001). Despite counteracting group dynamics in the EGMI condition, participants in the two interventions were statistically similar in post-intervention problem recognition and future drinking intentions. The results raise concerns over implementing individually-based interventions in group settings without making necessary adjustments.

Motives of Masters for the Teaching Profession: Development of the MMTP Questionnaire

Directory of Open Access Journals (Sweden)

Wil Meeus

2015-01-01

Full Text Available Increasing teacher shortages provide incentives for conducting research into the motives of future teachers aspiring to work in education. The present study builds on previous research into motivation for entering the teaching profession. Given the shortage of studies carried out with direct empirical foundations, multiphase factor analyses, and large respondent groups, the present research focuses on developing the questionnaire Motives of Masters for the Teaching Profession (MMTP while meeting these methodological criteria. Master’s students N=1200 described their motivations for entering the teaching profession. Confirmatory factor analysis N=707 was carried out in order to confirm the factor structure produced by the exploratory factor analysis N=145. On the basis of content and statistical arguments, a 7-factor solution was obtained and a 35-item questionnaire was produced. Future cross-contextual research on the MMTP should attempt to improve the generalizability of the questionnaire.

Bragg Curve Spectroscopy

International Nuclear Information System (INIS)

Gruhn, C.R.

1981-05-01

An alternative utilization is presented for the gaseous ionization chamber in the detection of energetic heavy ions, which is called Bragg Curve Spectroscopy (BCS). Conceptually, BCS involves using the maximum data available from the Bragg curve of the stopping heavy ion (HI) for purposes of identifying the particle and measuring its energy. A detector has been designed that measures the Bragg curve with high precision. From the Bragg curve the range from the length of the track, the total energy from the integral of the specific ionization over the track, the dE/dx from the specific ionization at the beginning of the track, and the Bragg peak from the maximum of the specific ionization of the HI are determined. This last signal measures the atomic number, Z, of the HI unambiguously

Investigation of mosaicity of epitaxic multilayers by the statistical theory of X-ray dynamical diffraction

International Nuclear Information System (INIS)

Li Ming; Mai Zhenhong; Li Jianhua; Li Chaorong; Cui Shufan

1995-01-01

Based on the statistical theory of X-ray dynamical diffraction for thin films, the mosaicity of three types of semiconductor epitaxic layers has been investigated by analyzing their rocking curves by the X-ray double-crystal diffraction method. It is shown that the statistical theory can provide quantitative information on the mosaicity of the epitaxic layers such as the mean size and the mean disorientation of mosaic blocks in the layers. Some misunderstandings in interpreting experimental data are cleared up by taking into account the effect of diffuse scattering. It is emphasized that attempts to obtain structural parameters of specimens from their rocking curves by means of the Takagi-Taupin equations for coherent fields only are not strictly correct since diffuse scattering causes additional changes in the tails of the rocking curves. (orig.)

Value of training on motivation among health workers in Narok County, Kenya.

Science.gov (United States)

Momanyi, George Osoro; Adoyo, Maureen Atieno; Mwangi, Eunice Muthoni; Mokua, Dennis Okari

2016-01-01

Training, as an additive human resources intervention is decisive to organizational performance. Employees require constant update of formal and informal knowledge alongside positive attitudes that have been defined as necessary in motivation leading to effectiveness in performance hence workplace training is tied to achieving organizational aims and objectives. The objective of this study was to determine the influence of training on motivation among health workers in Narok County, Kenya. A cross-sectional study utilizing a self administered questionnaire, targeting 237 health workers and 21 health managers was used. Data analysis was done using SPSS version 21 using descriptive statistics. Factor analysis was done on the training perception in relation to motivation. Majority of the respondents rated their motivation between 7 and 9 in the current health facility (35.4%), Sub-county (33.8%) and County (32.9%) with the median motivation level of 5. Majority of health workers 194 (81.9%) had received a form of training, of whom 191 (98.5%) indicated that on-job training was relevant to their tasks and that it motivated 192 (99.0%) of them to perform better due to coining skills to motivation. Training significantly predicted general motivation (p-value = 0.013), job satisfaction (p-value = .001), intrinsic job satisfaction (p-value = .001) and organisational commitment (p-value motivated health workforce in Narok County and recommended strengthening of current training initiatives by ensuring trainings are more regular and involvement of health workers in discussing their career development prospects.

Exact fast computation of band depth for large functional datasets: How quickly can one million curves be ranked?

KAUST Repository

Sun, Ying

2012-10-01

© 2012 John Wiley & Sons, Ltd. Band depth is an important nonparametric measure that generalizes order statistics and makes univariate methods based on order statistics possible for functional data. However, the computational burden of band depth limits its applicability when large functional or image datasets are considered. This paper proposes an exact fast method to speed up the band depth computation when bands are defined by two curves. Remarkable computational gains are demonstrated through simulation studies comparing our proposal with the original computation and one existing approximate method. For example, we report an experiment where our method can rank one million curves, evaluated at fifty time points each, in 12.4 seconds with Matlab.

Motivator-manager.

Science.gov (United States)

McDonald, Angelic P

2009-01-01

The radiologic career field has undergone radical changes in technology, regulatory compliance, and customer expectation.These changes often require dramatic alterations to processes,which can break down communication, create stress, and have a negative effect on department productivity. Motivation itself is a frequently analyzed and reported topic in professional publications. For this purpose, this literature review specifically researches motivation as identified by radiology administrators through Radiology Management. Three key elements surfaced as those with the most impact: (1) motivation is an intrinsic factor which can be influenced but not created, (2) clear attainable goals are an essential component of motivation,and (3) motivation begins with identification of employee needs.

Learning Curve? Which One?

Directory of Open Access Journals (Sweden)

Paulo Prochno

2004-07-01

Full Text Available Learning curves have been studied for a long time. These studies provided strong support to the hypothesis that, as organizations produce more of a product, unit costs of production decrease at a decreasing rate (see Argote, 1999 for a comprehensive review of learning curve studies. But the organizational mechanisms that lead to these results are still underexplored. We know some drivers of learning curves (ADLER; CLARK, 1991; LAPRE et al., 2000, but we still lack a more detailed view of the organizational processes behind those curves. Through an ethnographic study, I bring a comprehensive account of the first year of operations of a new automotive plant, describing what was taking place on in the assembly area during the most relevant shifts of the learning curve. The emphasis is then on how learning occurs in that setting. My analysis suggests that the overall learning curve is in fact the result of an integration process that puts together several individual ongoing learning curves in different areas throughout the organization. In the end, I propose a model to understand the evolution of these learning processes and their supporting organizational mechanisms.

Supplementary Material for: Growth curve registration for evaluating salinity tolerance in barley

KAUST Repository

Meng, Rui

2017-01-01

Abstract Background Smarthouses capable of non-destructive, high-throughput plant phenotyping collect large amounts of data that can be used to understand plant growth and productivity in extreme environments. The challenge is to apply the statistical tool that best analyzes the data to study plant traits, such as salinity tolerance, or plant-growth-related traits. Results We derive family-wise salinity sensitivity (FSS) growth curves and use registration techniques to summarize growth patterns of HEB-25 barley families and the commercial variety, Navigator. We account for the spatial variation in smarthouse microclimates and in temporal variation across phenotyping runs using a functional ANOVA model to derive corrected FSS curves. From FSS, we derive corrected values for family-wise salinity tolerance, which are strongly negatively correlated with Na but not significantly with K, indicating that Na content is an important factor affecting salinity tolerance in these families, at least for plants of this age and grown in these conditions. Conclusions Our family-wise methodology is suitable for analyzing the growth curves of a large number of plants from multiple families. The corrected curves accurately account for the spatial and temporal variations among plants that are inherent to high-throughput experiments.

A statistical approach to evaluate the performance of cardiac biomarkers in predicting death due to acute myocardial infarction: time-dependent ROC curve

Science.gov (United States)

Karaismailoğlu, Eda; Dikmen, Zeliha Günnur; Akbıyık, Filiz; Karaağaoğlu, Ahmet Ergun

2018-04-30

Background/aim: Myoglobin, cardiac troponin T, B-type natriuretic peptide (BNP), and creatine kinase isoenzyme MB (CK-MB) are frequently used biomarkers for evaluating risk of patients admitted to an emergency department with chest pain. Recently, time- dependent receiver operating characteristic (ROC) analysis has been used to evaluate the predictive power of biomarkers where disease status can change over time. We aimed to determine the best set of biomarkers that estimate cardiac death during follow-up time. We also obtained optimal cut-off values of these biomarkers, which differentiates between patients with and without risk of death. A web tool was developed to estimate time intervals in risk. Materials and methods: A total of 410 patients admitted to the emergency department with chest pain and shortness of breath were included. Cox regression analysis was used to determine an optimal set of biomarkers that can be used for estimating cardiac death and to combine the significant biomarkers. Time-dependent ROC analysis was performed for evaluating performances of significant biomarkers and a combined biomarker during 240 h. The bootstrap method was used to compare statistical significance and the Youden index was used to determine optimal cut-off values. Results : Myoglobin and BNP were significant by multivariate Cox regression analysis. Areas under the time-dependent ROC curves of myoglobin and BNP were about 0.80 during 240 h, and that of the combined biomarker (myoglobin + BNP) increased to 0.90 during the first 180 h. Conclusion: Although myoglobin is not clinically specific to a cardiac event, in our study both myoglobin and BNP were found to be statistically significant for estimating cardiac death. Using this combined biomarker may increase the power of prediction. Our web tool can be useful for evaluating the risk status of new patients and helping clinicians in making decisions.

Contractibility of curves

Directory of Open Access Journals (Sweden)

Janusz Charatonik

1991-11-01

Full Text Available Results concerning contractibility of curves (equivalently: of dendroids are collected and discussed in the paper. Interrelations tetween various conditions which are either sufficient or necessary for a curve to be contractible are studied.

Roc curves for continuous data

CERN Document Server

Krzanowski, Wojtek J

2009-01-01

Since ROC curves have become ubiquitous in many application areas, the various advances have been scattered across disparate articles and texts. ROC Curves for Continuous Data is the first book solely devoted to the subject, bringing together all the relevant material to provide a clear understanding of how to analyze ROC curves.The fundamental theory of ROC curvesThe book first discusses the relationship between the ROC curve and numerous performance measures and then extends the theory into practice by describing how ROC curves are estimated. Further building on the theory, the authors prese

National proficiency-gain curves for minimally invasive gastrointestinal cancer surgery.

Science.gov (United States)

Mackenzie, H; Markar, S R; Askari, A; Ni, M; Faiz, O; Hanna, G B

2016-01-01

Minimal access surgery for gastrointestinal cancer has short-term benefits but is associated with a proficiency-gain curve. The aim of this study was to define national proficiency-gain curves for minimal access colorectal and oesophagogastric surgery, and to determine the impact on clinical outcomes. All adult patients undergoing minimal access oesophageal, colonic and rectal surgery between 2002 and 2012 were identified from the Hospital Episode Statistics database. Proficiency-gain curves were created using risk-adjusted cumulative sum analysis. Change points were identified, and bootstrapping was performed with 1000 iterations to identify a confidence level. The primary outcome was 30-day mortality; secondary outcomes were 90-day mortality, reintervention, conversion and length of hospital stay. Some 1696, 15 008 and 16 701 minimal access oesophageal, rectal and colonic cancer resections were performed during the study period. The change point in the proficiency-gain curve for 30-day mortality for oesophageal, rectal and colonic surgery was 19 (confidence level 98·4 per cent), 20 (99·2 per cent) and three (99·5 per cent) procedures; the mortality rate fell from 4·0 to 2·0 per cent (relative risk reduction (RRR) 0·50, P = 0·033), from 2·1 to 1·2 per cent (RRR 0·43, P curve for reintervention in oesophageal, rectal and colonic resection was 19 (98·1 per cent), 32 (99·5 per cent) and 26 (99·2 per cent) procedures respectively. There were also significant proficiency-gain curves for 90-day mortality, conversion and length of stay. The introduction of minimal access gastrointestinal cancer surgery has been associated with a proficiency-gain curve for mortality and major morbidity at a national level. Unnecessary patient harm should be avoided by appropriate training and monitoring of new surgical techniques. © 2015 BJS Society Ltd Published by John Wiley & Sons Ltd.

Food Choice Motives among the Students of a Dental Institution in ...

African Journals Online (AJOL)

Food is a focus of social interaction ... the role of other influences on food choice. ... Results indicated statistically significant differences in terms of food choice .... This interpretation would support the argument that ... Gender, age and motives underlying food choice affected the .... eating behavior and body weight regulation.

Foundations and applications of statistics an introduction using $Mathsf{R}$

CERN Document Server

Pruim, Randall

2018-01-01

Foundations and Applications of Statistics simultaneously emphasizes both the foundational and the computational aspects of modern statistics. Engaging and accessible, this book is useful to undergraduate students with a wide range of backgrounds and career goals. The exposition immediately begins with statistics, presenting concepts and results from probability along the way. Hypothesis testing is introduced very early, and the motivation for several probability distributions comes from p-value computations. Pruim develops the students' practical statistical reasoning through explicit examples and through numerical and graphical summaries of data that allow intuitive inferences before introducing the formal machinery. The topics have been selected to reflect the current practice in statistics, where computation is an indispensible tool. In this vein, the statistical computing environment \\mathsf{R} is used throughout the text and is integral to the exposition. Attention is paid to developing students' mathem...

Hierarchical statistical modeling of xylem vulnerability to cavitation.

Science.gov (United States)

Ogle, Kiona; Barber, Jarrett J; Willson, Cynthia; Thompson, Brenda

2009-01-01

Cavitation of xylem elements diminishes the water transport capacity of plants, and quantifying xylem vulnerability to cavitation is important to understanding plant function. Current approaches to analyzing hydraulic conductivity (K) data to infer vulnerability to cavitation suffer from problems such as the use of potentially unrealistic vulnerability curves, difficulty interpreting parameters in these curves, a statistical framework that ignores sampling design, and an overly simplistic view of uncertainty. This study illustrates how two common curves (exponential-sigmoid and Weibull) can be reparameterized in terms of meaningful parameters: maximum conductivity (k(sat)), water potential (-P) at which percentage loss of conductivity (PLC) =X% (P(X)), and the slope of the PLC curve at P(X) (S(X)), a 'sensitivity' index. We provide a hierarchical Bayesian method for fitting the reparameterized curves to K(H) data. We illustrate the method using data for roots and stems of two populations of Juniperus scopulorum and test for differences in k(sat), P(X), and S(X) between different groups. Two important results emerge from this study. First, the Weibull model is preferred because it produces biologically realistic estimates of PLC near P = 0 MPa. Second, stochastic embolisms contribute an important source of uncertainty that should be included in such analyses.

Penultimate modeling of spatial extremes: statistical inference for max-infinitely divisible processes

KAUST Repository

Huser, Raphaë l; Opitz, Thomas; Thibaud, Emeric

2018-01-01

Extreme-value theory for stochastic processes has motivated the statistical use of max-stable models for spatial extremes. However, fitting such asymptotic models to maxima observed over finite blocks is problematic when the asymptotic stability

Directed Motivational Currents: Using vision to create effective motivational pathways

Directory of Open Access Journals (Sweden)

Christine Muir

2013-10-01

Full Text Available Vision, that is, the mental representation of the sensory experience of a future goal state (involving imagination and imagery, is currently at the forefront of motivational innovation, and in recent years it has been seen increasingly more often in the motivational tool kit of practicing language teachers. Theories such as Dörnyei’s L2 motivational self system have explored the power that creating effective visions can harness (see, e.g., Dörnyei & Kubanyiova, 2014 and when viewed in conjunction with other current research avenues, such as future time perspective and dynamic systems theory, vision offers exciting potential. A Directed Motivational Current is a new motivational construct that we suggest is capable of integrating many current theoretical strands with vision: It can be described as a motivational drive which energises long-term, sustained behaviour (such as language learning, and through placing vision and goals as critical central components within this construct, it offers real and practical motivational potential. In this conceptual paper, we first discuss current understandings of vision and of Directed Motivational Currents, and then analyse how they may be optimally integrated and employed to create effective motivational pathways in language learning environments.

Atlas of stress-strain curves

CERN Document Server

2002-01-01

The Atlas of Stress-Strain Curves, Second Edition is substantially bigger in page dimensions, number of pages, and total number of curves than the previous edition. It contains over 1,400 curves, almost three times as many as in the 1987 edition. The curves are normalized in appearance to aid making comparisons among materials. All diagrams include metric (SI) units, and many also include U.S. customary units. All curves are captioned in a consistent format with valuable information including (as available) standard designation, the primary source of the curve, mechanical properties (including hardening exponent and strength coefficient), condition of sample, strain rate, test temperature, and alloy composition. Curve types include monotonic and cyclic stress-strain, isochronous stress-strain, and tangent modulus. Curves are logically arranged and indexed for fast retrieval of information. The book also includes an introduction that provides background information on methods of stress-strain determination, on...

Head-circumference distribution in a large primary care network differs from CDC and WHO curves.

Science.gov (United States)

Daymont, Carrie; Hwang, Wei-Ting; Feudtner, Chris; Rubin, David

2010-10-01

To compare currently available head-circumference growth curves to curves constructed from clinical measurements from patients in a large US primary care network (PCN). We performed a retrospective cohort study of 75 412 patients in an urban-suburban PCN. Patients with a birth weight of curves. The PCN curves were most similar to the National Center for Health Statistics (NCHS) curves and were substantially different from the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) curves. The overall proportion of observations above the 95th percentile was 4.9% (PCN), 6.2% (NCHS), 8.6% (CDC), and 14.0% (WHO). The proportion below the 5th percentile was 4.4% (PCN), 5.1% (NCHS), 2.9% (CDC), and 2.3% (WHO). When using the CDC curves, the proportion above the 95th percentile increased from 0.2% for children younger than 2 weeks to 11.8% for children 12 months old. When using the WHO curves, the proportion above the 95th percentile was >5% at all ages, with a maximum of 18.0% for children older than 24 months. The CDC and WHO head-circumference curves describe different distributions than the clinical measurements in our PCN population, especially for children with larger heads. The resulting percentile misclassification may delay diagnosis in children with intracranial pathology in very young infants and spur unnecessary evaluation of healthy children older than 6 months.

Motivating Information Technology Professionals: The case of New Zealand

Directory of Open Access Journals (Sweden)

Shoaib Ahmed

2017-06-01

Full Text Available IT professionals play a critical role in organizations. Research indicates that they may be unique in their attitudes toward motivation and job satisfaction. In New Zealand, a shortage of skilled professionals may contribute to or impact on motivation. Using a modified model of Herzberg’s two-factor theory by Smerek and Peterson (2007, this research seeks to answer the question: what motivates New Zealand IT professionals? In response, an online questionnaire was distributed to a population of New Zealand IT professionals and the data analysed using Partial Least Squares to understand the relationship between the various dimensions of job satisfaction, the impact of personal and job characteristics, and turnover intention. The findings show that the New Zealand IT professional is primarily motivated by the nature of his or her work, followed by perceptions of responsibility, and how supervisors encourage an environment for such. Satisfaction with salary is a predictor to a lesser degree. Perhaps somewhat surprisingly, professional growth opportunities, career advancement, and recognition do not have a statistically-significant positive association with motivation. We conclude that, to motivate their IT workforce, organizations should: 1 focus on the nature of the jobs that IT professionals undertake; 2 train supervisors to provide an empowering environment; 3 offer competitive salaries to retain top talent; 4 not hesitate to employ IT professionals born outside New Zealand; and 5 take account of the singularities of the New Zealand labour market in seeking to attract, recruit and retain IT professionals. Implications for policy, practice and theory are discussed.

CORSSA: The Community Online Resource for Statistical Seismicity Analysis

Science.gov (United States)

Michael, Andrew J.; Wiemer, Stefan

2010-01-01

Statistical seismology is the application of rigorous statistical methods to earthquake science with the goal of improving our knowledge of how the earth works. Within statistical seismology there is a strong emphasis on the analysis of seismicity data in order to improve our scientific understanding of earthquakes and to improve the evaluation and testing of earthquake forecasts, earthquake early warning, and seismic hazards assessments. Given the societal importance of these applications, statistical seismology must be done well. Unfortunately, a lack of educational resources and available software tools make it difficult for students and new practitioners to learn about this discipline. The goal of the Community Online Resource for Statistical Seismicity Analysis (CORSSA) is to promote excellence in statistical seismology by providing the knowledge and resources necessary to understand and implement the best practices, so that the reader can apply these methods to their own research. This introduction describes the motivation for and vision of CORRSA. It also describes its structure and contents.

Tornado-Shaped Curves

Science.gov (United States)

Martínez, Sol Sáez; de la Rosa, Félix Martínez; Rojas, Sergio

2017-01-01

In Advanced Calculus, our students wonder if it is possible to graphically represent a tornado by means of a three-dimensional curve. In this paper, we show it is possible by providing the parametric equations of such tornado-shaped curves.

In vivo Comet assay--statistical analysis and power calculations of mice testicular cells.

Science.gov (United States)

Hansen, Merete Kjær; Sharma, Anoop Kumar; Dybdahl, Marianne; Boberg, Julie; Kulahci, Murat

2014-11-01

The in vivo Comet assay is a sensitive method for evaluating DNA damage. A recurrent concern is how to analyze the data appropriately and efficiently. A popular approach is to summarize the raw data into a summary statistic prior to the statistical analysis. However, consensus on which summary statistic to use has yet to be reached. Another important consideration concerns the assessment of proper sample sizes in the design of Comet assay studies. This study aims to identify a statistic suitably summarizing the % tail DNA of mice testicular samples in Comet assay studies. A second aim is to provide curves for this statistic outlining the number of animals and gels to use. The current study was based on 11 compounds administered via oral gavage in three doses to male mice: CAS no. 110-26-9, CAS no. 512-56-1, CAS no. 111873-33-7, CAS no. 79-94-7, CAS no. 115-96-8, CAS no. 598-55-0, CAS no. 636-97-5, CAS no. 85-28-9, CAS no. 13674-87-8, CAS no. 43100-38-5 and CAS no. 60965-26-6. Testicular cells were examined using the alkaline version of the Comet assay and the DNA damage was quantified as % tail DNA using a fully automatic scoring system. From the raw data 23 summary statistics were examined. A linear mixed-effects model was fitted to the summarized data and the estimated variance components were used to generate power curves as a function of sample size. The statistic that most appropriately summarized the within-sample distributions was the median of the log-transformed data, as it most consistently conformed to the assumptions of the statistical model. Power curves for 1.5-, 2-, and 2.5-fold changes of the highest dose group compared to the control group when 50 and 100 cells were scored per gel are provided to aid in the design of future Comet assay studies on testicular cells. Copyright © 2014 Elsevier B.V. All rights reserved.

Multiple motives and persuasive communication : Creative elaboration as a result of impression motivation and accuracy motivation

NARCIS (Netherlands)

Nienhuis, AE; Manstead, ASR; Spears, R

The authors examined the influence of impression motivation (Experiments 1 and 2) and the combined effects of accuracy motivation and impression motivation (Experiment 3) on the elaboration of persuasive messages as reflected in attitude change and cognitive responses. Intermediate levels of

A versatile curve-fit model for linear to deeply concave rank abundance curves

NARCIS (Netherlands)

Neuteboom, J.H.; Struik, P.C.

2005-01-01

A new, flexible curve-fit model for linear to concave rank abundance curves was conceptualized and validated using observational data. The model links the geometric-series model and log-series model and can also fit deeply concave rank abundance curves. The model is based ¿ in an unconventional way

Motivating pharmacy employees.

Science.gov (United States)

White, S J; Generali, J A

1984-07-01

Concepts from theories of motivation are used to suggest methods for improving the motivational environment of hospital pharmacy departments. Motivation--the state of being stimulated to take action to achieve a goal or to satisfy a need--comes from within individuals, but hospital pharmacy managers can facilitate motivation by structuring the work environment so that it satisfies employees' needs. Concepts from several theories of motivation are discussed, including McGregor's theory X and theory Y assumptions, Maslow's hierarchy of needs theory, Herzberg's motivation hygiene theory, and Massey's value system theory. Concepts from the Japanese style of management that can be used to facilitate motivation, such as quality circles, also are described. The autocratic, participative, and laissez faire styles of leadership are discussed in the context of the motivation theories, and suggested applications of theoretical concepts to practice are presented.

"What If" Analyses: Ways to Interpret Statistical Significance Test Results Using EXCEL or "R"

Science.gov (United States)

Ozturk, Elif

2012-01-01

The present paper aims to review two motivations to conduct "what if" analyses using Excel and "R" to understand the statistical significance tests through the sample size context. "What if" analyses can be used to teach students what statistical significance tests really do and in applied research either prospectively to estimate what sample size…

The Motivational Climate and Intrinsic Motivation in the Rehabilitation Setting.

Science.gov (United States)

Brinkman-Majewski, Rachel E; Weiss, Windee M

2018-02-06

The motivational climate created by the athletic trainer in rehabilitation may be critical in influencing athletes' intrinsic motivation and other psychosocial outcomes in the rehabilitation and the recovery process. The purpose of this study was to examine intercollegiate athletes' perceptions of the motivational climate in the rehabilitation setting. Specifically, examining if perceptions of the motivational climate can predict athletes' levels of intrinsic motivation with rehabilitation as well as the relationship between perceptions of the motivational climate and athlete demographics (gender, starter status, athletic trainer gender, etc). Cross-sectional, descriptive research. College sport team and athletic training center. NCAA Division II intercollegiate athletes from one institution (n = 187; 125 male, 62 female). Paper-based survey measuring: mastery and performance perceptions of the motivational climate in rehabilitation, athletes' goal orientation in sport, athletes' levels of motivation in rehabilitation. Perceptions of a performance climate was positively related to intrinsic motivation effort-improvement (effect size=25.34%). Perceptions of a mastery climate were positively related to interest-enjoyment and perceived competence and negatively related to tension-pressure (effect size=39.03%). In general, female athletes, as well as athletes with a female athletic trainer, had significantly higher perceptions of mastery motivational climate effort-improvement compared to male athletes and athletes with male athletic trainers. While male athletes and athletes with male athletic trainers had higher perceptions of intra-team member rivalry in rehabilitation. The athlete's gender and goal orientation, as well as the gender of the athletic trainer creating the motivational climate, can influence whether the environment is perceived as more mastery or performance. The recovering athletes' perceptions of the climate in rehabilitation can, in turn, affect

An Empirical Analysis Of The Motivational Value Of Corporate Social Responsibility Actions In Sugar Production Firms In Western Kenya

Directory of Open Access Journals (Sweden)

Dr. Janet N. Manyasi

2015-08-01

Full Text Available The relationship between CSR activities and employee motivation is still an area that is under- researched. Few studies have tried to compare the motivational value of the different types of CSR actions in the company especially in the manufacturing firms in Kenya. This study therefore investigated the effect of different types of corporate social responsibility activities on the motivation of employees in sugar production firms in western Kenya. The study employed a descriptive survey design to investigate this relationship. Stratified and random sampling techniques were used to obtain a sample of 306 respondents from the research population. A self administered questionnaire was used to collect primary data which was analyzed statistically with the help of the SPSS software 20. To determine the statistical associations between the different types of CSR activities and employee motivation correlation was used. The results from the hypotheses testing indicated that there are significant positive correlations between all the types of CSR activities and employee motivation. These are customers-related the local community-related the business partners-related and employees-related CSR activities. On the whole each type of CSR activities had its own strength and degree to which it could promote or influence employee motivation.

Personal dosimetry statistics and specifics of low dose evaluation

International Nuclear Information System (INIS)

Avila, R.E.; Gómez Salinas, R.A.; Oyarzún Cortés, C.H.

2015-01-01

The dose statistics of a personal dosimetry service, considering 35,000+ readings, display a sharp peak at low dose (below 0.5 mSv) with skewness to higher values. A measure of the dispersion is that approximately 65% of the doses fall below the average plus 2 standard deviations, an observation which may prove helpful to radiation protection agencies. Categorizing the doses by the concomitant use of a finger ring dosimeter, that skewness is larger in the whole body, and ring dosimeters. The use of Harshaw 5500 readers at high gain leads to frequent values of the glow curve that are judged to be spurious, i.e. values not belonging to the roughly normal noise over the curve. A statistical criterion is shown for identifying those anomalous values, and replacing them with the local behavior, as fit by a cubic polynomial. As a result, the doses above 0.05 mSv which are affected by more than 2% comprise over 10% of the data base. The low dose peak of the statistics, above, has focused our attention on the evaluation of LiF(Mg,Ti) dosimeters exposed at low dose, and read with Harshaw 5500 readers. The standard linear procedure, via an overall reader calibration factor, is observed to fail at low dose, in detailed calibrations from 0.02 mSv to 1 Sv. A significant improvement is achieved by a piecewise polynomials calibration curve. A cubic, at low dose is matched, at ∼10 mSv, in value and first derivative, to a linear dependence at higher doses. This improvement is particularly noticeable below 2 mSv, where over 60% of the evaluated dosimeters are found. (author)

Client Motivation for Therapy Scale: a measure of intrinsic motivation, extrinsic motivation, and amotivation for therapy.

Science.gov (United States)

Pelletier, L G; Tuson, K M; Haddad, N K

1997-04-01

The purpose of this study was to examine the psychometric properties of a new measure of client motivation for therapy, the Client Motivation for Therapy Scale. This scale is designed to measure client's Intrinsic Motivation, four forms of regulation for Extrinsic Motivation (integrated, identified, introjected, and external regulation), and Amotivation for therapy. These subscales correspond to different forms of motivation identified by Deci and Ryan (1985) and fall along a self-determination continuum. An experimental version of the scale, along with related scales, was distributed to a total sample of 138 clients involved in therapy. The results supported the factor structure of the scale and revealed a satisfactory level of internal consistency. Correlations among the subscales revealed a simplex pattern that, in general, provides support for the self-determination continuum and the construct validity of the scale. Implications for research on client motivation for therapy are discussed.

Variability analysis of AGN: a review of results using new statistical criteria

Science.gov (United States)

Zibecchi, L.; Andruchow, I.; Cellone, S. A.; Romero, G. E.; Combi, J. A.

We present here a re-analysis of the variability results of a sample of active galactic nuclei (AGN), which have been observed on several sessions with the 2.15 m "Jorge Sahade" telescope (CASLEO), San Juan, Argentina, and whose results are published (Romero et al. 1999, 2000, 2002; Cellone et al. 2000). The motivation for this new analysis is the implementation, dur- ing the last years, of improvements in the statistical criteria applied, taking quantitatively into account the incidence of the photometric errors (Cellone et al. 2007). This work is framed as a first step in an integral study on the statistical estimators of AGN variability. This study is motivated by the great diversity of statistical tests that have been proposed to analyze the variability of these objects. Since we note that, in some cases, the results of the object variability depend on the test used, we attempt to make a com- parative study of the various tests and analyze, under the given conditions, which of them is the most efficient and reliable.

In-Vehicle Dynamic Curve-Speed Warnings at High-Risk Rural Curves

Science.gov (United States)

2018-03-01

Lane-departure crashes at horizontal curves represent a significant portion of fatal crashes on rural Minnesota roads. Because of this, solutions are needed to aid drivers in identifying upcoming curves and inform them of a safe speed at which they s...

Multi-messenger Light Curves from Gamma-Ray Bursts in the Internal Shock Model

Energy Technology Data Exchange (ETDEWEB)

Bustamante, Mauricio [Center for Cosmology and AstroParticle Physics (CCAPP), The Ohio State University, Columbus, OH 43210 (United States); Heinze, Jonas; Winter, Walter [Deutsches Elektronen-Synchrotron (DESY), Platanenallee 6, D-15738 Zeuthen (Germany); Murase, Kohta, E-mail: bustamanteramirez.1@osu.edu, E-mail: walter.winter@desy.de, E-mail: jonas.heinze@desy.de, E-mail: murase@psu.edu [Center for Particle and Gravitational Astrophysics, The Pennsylvania State University, University Park, PA16802 (United States)

2017-03-01

Gamma-ray bursts (GRBs) are promising as sources of neutrinos and cosmic rays. In the internal shock scenario, blobs of plasma emitted from a central engine collide within a relativistic jet and form shocks, leading to particle acceleration and emission. Motivated by present experimental constraints and sensitivities, we improve the predictions of particle emission by investigating time-dependent effects from multiple shocks. We produce synthetic light curves with different variability timescales that stem from properties of the central engine. For individual GRBs, qualitative conclusions about model parameters, neutrino production efficiency, and delays in high-energy gamma-rays can be deduced from inspection of the gamma-ray light curves. GRBs with fast time variability without additional prominent pulse structure tend to be efficient neutrino emitters, whereas GRBs with fast variability modulated by a broad pulse structure can be inefficient neutrino emitters and produce delayed high-energy gamma-ray signals. Our results can be applied to quantitative tests of the GRB origin of ultra-high-energy cosmic rays, and have the potential to impact current and future multi-messenger searches.

Multi-messenger light curves from gamma-ray bursts in the internal shock model

Energy Technology Data Exchange (ETDEWEB)

Bustamante, Mauricio [Ohio State Univ., Columbus, OH (United States). Center for Cosmology and AstroParticle Physics (CCAPP); Ohio State Univ., Columbus, OH (United States). Dept. of Physics; Murase, Kohta [Pennsylvania State Univ., University Park, PA (United States). Center for Particle and Gravitational Astrophysics; Pennsylvania State Univ., University Park, PA (United States). Dept. of Astronomy and Astrophysics; Winter, Walter [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

2016-06-15

Gamma-ray bursts (GRBs) are promising as sources of neutrinos and cosmic rays. In the internal shock scenario, blobs of plasma emitted from a central engine collide within a relativistic jet and form shocks, leading to particle acceleration and emission. Motivated by present experimental constraints and sensitivities, we improve the predictions of particle emission by investigating time-dependent effects from multiple shocks. We produce synthetic light curves with different variability timescales that stem from properties of the central engine. For individual GRBs, qualitative conclusions about model parameters, neutrino production efficiency, and delays in high-energy gamma rays can be deduced from inspection of the gamma-ray light curves. GRBs with fast time variability without additional prominent pulse structure tend to be efficient neutrino emitters, whereas GRBs with fast variability modulated by a broad pulse structure tend to be inefficient neutrino emitters and produce delayed high-energy gamma-ray signals. Our results can be applied to quantitative tests of the GRB origin of ultra-high-energy cosmic rays, and have the potential to impact current and future multi-messenger searches.

ELECTRICAL CONDUCTIVITY OF SOYBEAN SEED CULTIVARS AND ADJUSTED MODELS OF LEAKAGE CURVES ALONG THE TIME

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ADRIANA RITA SALINAS

2010-01-01

Full Text Available The objective of this work was to study the behavior of ten soybean [Glycine max (L. Merr.] cultivars using the electrical conductivity (EC test by the comparison of curves of the accumulative electrolyte leakage along the time and to establish the statistical model that allow the best adjust of the curves. Ten soybean cultivars were used and they were mechanically harvested in 2004 in the EEA Oliveros, Santa Fe, Argentina. Measurements of EC were made for 100 individual seeds of each cultivar during 20 hours of immersion at intervals of 1 hour using an equipment that permit an individual seed analysis (Seed Automatic Analyzer SAD 9000S. There were proposed two statistical models to study the EC along the time of the 10 cultivars studied using SAS Statistics Program, to select the model that better allow us to understand the EC behavior along the time. Model 1 allowed to make comparisons of EC along the time between cultivars and to study the influence of the production environment on the physiological quality of soybean seeds. The time to reach the stabilization of the EC must not be lower than 19 hours for the different cultivars.

The relationship between extrinsic motivation, job satisfaction and life satisfaction amongst employees in a public organisation

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Chengedzai Mafini

2014-04-01

Research purpose: To examine the relationships between extrinsic motivation, job satisfaction and life satisfaction amongst employees in a public organisation. Motivation for the study: Labour strife is an endemic phenomenon in South Africa’s public sector as evidenced by the high incidences of industrial action and labour turnover. This study contributes to this subject by identifying the extrinsic factors that could be optimised with a view to enhancing job and life satisfaction amongst government employees. Research approach, design and method: The study used the quantitative research survey approach: a questionnaire was administered to 246 employees in a South African public organisation. Extrinsic motivation factors were identified using principal components analysis. Mean score ranking was used to compare the relative importance of all factors. The conceptual framework was tested using Spearman’s rank correlation analysis and linear regression analysis. Main findings: Statistically significant relationships were observed between job satisfaction and four extrinsic motivation factors: remuneration, quality of work life, supervision and teamwork. The relationship with promotion was insignificant, but a statistically significant relationship was established with life satisfaction. Practical/managerial implications: The findings may be used to implement strategies for enhancing employee performance and industrial relations within public organisations. Contribution/value-add: The study provides evidence of the interplay between extrinsic motivation, job satisfaction and life satisfaction for public servants in developing countries.

Geodesic curve-of-sight formulae for the cosmic microwave background: a unified treatment of redshift, time delay, and lensing

International Nuclear Information System (INIS)

Saito, Ryo; Naruko, Atsushi; Hiramatsu, Takashi; Sasaki, Misao

2014-01-01

In this paper, we introduce a new approach to a treatment of the gravitational effects (redshift, time delay and lensing) on the observed cosmic microwave background (CMB) anisotropies based on the Boltzmann equation. From the Liouville's theorem in curved spacetime, the intensity of photons is conserved along a photon geodesic when non-gravitational scatterings are absent. Motivated by this fact, we derive a second-order line-of-sight formula by integrating the Boltzmann equation along a perturbed geodesic (curve) instead of a background geodesic (line). In this approach, the separation of the gravitational and intrinsic effects are manifest. This approach can be considered as a generalization of the remapping approach of CMB lensing, where all the gravitational effects can be treated on the same footing

HOW TO MOTIVATE OTHERS AND MOTIVATE YOURSELF IN TIMES OF CRISIS

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José Navarro

2014-01-01

Full Text Available Work motivation is an adaptive behavior with which we respond effectively to our job demands. The current crisis has introduced changes in some basic working conditions (timetable, salary, security, etc. that are affecting a type of motivation determined by the external conditions of the worker. Research shows that this nonself-determined motivation is weaker in intensity and less persistent over time than self-determined motivation. Based on the research we have been developing in recent years, we propose some guidelines that focus on encouraging a more autonomous and self-determined motivation. Much of this research has been based on a dynamic understanding of work motivation. Understanding the dynamics of motivation gives us useful guidelines for action.

Value of training on motivation among health workers in Narok County, Kenya

Science.gov (United States)

Momanyi, George Osoro; Adoyo, Maureen Atieno; Mwangi, Eunice Muthoni; Mokua, Dennis Okari

2016-01-01

Introduction Training, as an additive human resources intervention is decisive to organizational performance. Employees require constant update of formal and informal knowledge alongside positive attitudes that have been defined as necessary in motivation leading to effectiveness in performance hence workplace training is tied to achieving organizational aims and objectives. The objective of this study was to determine the influence of training on motivation among health workers in Narok County, Kenya. Methods A cross-sectional study utilizing a self administered questionnaire, targeting 237 health workers and 21 health managers was used. Data analysis was done using SPSS version 21 using descriptive statistics. Factor analysis was done on the training perception in relation to motivation. Results Majority of the respondents rated their motivation between 7 and 9 in the current health facility (35.4%), Sub-county (33.8%) and County (32.9%) with the median motivation level of 5. Majority of health workers 194 (81.9%) had received a form of training, of whom 191 (98.5%) indicated that on-job training was relevant to their tasks and that it motivated 192 (99.0%) of them to perform better due to coining skills to motivation. Training significantly predicted general motivation (p-value = 0.013), job satisfaction (p-value = .001), intrinsic job satisfaction (p-value = .001) and organisational commitment (p-value motivated health workforce in Narok County and recommended strengthening of current training initiatives by ensuring trainings are more regular and involvement of health workers in discussing their career development prospects. PMID:27516826

DEVELOPING AN EXCELLENT SEDIMENT RATING CURVE FROM ONE HYDROLOGICAL YEAR SAMPLING PROGRAMME DATA: APPROACH

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Preksedis M. Ndomba

2008-01-01

Full Text Available This paper presents preliminary findings on the adequacy of one hydrological year sampling programme data in developing an excellent sediment rating curve. The study case is a 1DD1 subcatchment in the upstream of Pangani River Basin (PRB, located in the North Eastern part of Tanzania. 1DD1 is the major runoff-sediment contributing tributary to the downstream hydropower reservoir, the Nyumba Ya Mungu (NYM. In literature sediment rating curve method is known to underestimate the actual sediment load. In the case of developing countries long-term sediment sampling monitoring or conservation campaigns have been reported as unworkable options. Besides, to the best knowledge of the authors, to date there is no consensus on how to develop an excellent rating curve. Daily-midway and intermittent-cross section sediment samples from Depth Integrating sampler (D-74 were used to calibrate the subdaily automatic sediment pumping sampler (ISCO 6712 near bank point samples for developing the rating curve. Sediment load correction factors were derived from both statistical bias estimators and actual sediment load approaches. It should be noted that the ongoing study is guided by findings of other studies in the same catchment. For instance, long term sediment yield rate estimated based on reservoir survey validated the performance of the developed rating curve. The result suggests that excellent rating curve could be developed from one hydrological year sediment sampling programme data. This study has also found that uncorrected rating curve underestimates sediment load. The degreeof underestimation depends on the type of rating curve developed and data used.

Exercise Participation Motives and Engaging In Sports Activity among University of Ljubljana Students