Gender differences in the factors predicting initial engagement at cardiac rehabilitation.

Science.gov (United States)

Galdas, Paul Michael; Harrison, Alexander Stephen; Doherty, Patrick

2018-01-01

To determine whether there are gender differences in the factors that predict attendance at the initial cardiac rehabilitation baseline assessment (CR engagement) after referral. Using data from the National Audit of Cardiac Rehabilitation, we analysed data on 95 638 patients referred to CR following a cardiovascular diagnosis/treatment between 2013 and 2016. Eighteen factors that have been shown in previous research to be important predictors of CR participation were investigated and grouped into four categories: sociodemographic factors, cardiac risk factors, patient medical status and service-level factors. Logistic binary regression models were built for male patients and female patients, assessing the likelihood for CR engagement. Each included predictors such as age, number of comorbidities and social deprivation score. There were no important differences in the factors that predict the likelihood of CR engagement in men and women. Seven factors associated with a reduced probability of CR engagement, and eight factors associated with increased probability, were identified. Fourteen of the 15 factors identified as predicting the likelihood for engagement/non-engagement were the same for both men and women. Increasing age, being South Asian or non-white ethnicity (other than Black) and being single were all associated with a reduced likelihood of attending an initial CR baseline assessment in both men and women. Male patients with diabetes were 11% less likely to engage with CR; however, there was no significant association in women. Results showed that the overwhelmingly important determinant of CR engagement observed in both men and women was receiving an invitation to attend an assessment session (OR 4.223 men/4.033women; pgender differences in predictors of CR uptake should probably be more nuanced and informed by the stage of the patient care pathway.

Numerical and Experimental Validation of a New Damage Initiation Criterion

Science.gov (United States)

Sadhinoch, M.; Atzema, E. H.; Perdahcioglu, E. S.; van den Boogaard, A. H.

2017-09-01

Most commercial finite element software packages, like Abaqus, have a built-in coupled damage model where a damage evolution needs to be defined in terms of a single fracture energy value for all stress states. The Johnson-Cook criterion has been modified to be Lode parameter dependent and this Modified Johnson-Cook (MJC) criterion is used as a Damage Initiation Surface (DIS) in combination with the built-in Abaqus ductile damage model. An exponential damage evolution law has been used with a single fracture energy value. Ultimately, the simulated force-displacement curves are compared with experiments to validate the MJC criterion. 7 out of 9 fracture experiments were predicted accurately. The limitations and accuracy of the failure predictions of the newly developed damage initiation criterion will be discussed shortly.

Predicting initial client engagement with community mental health services by routinely measured data

NARCIS (Netherlands)

Roeg, D.P.K.; van de Goor, L.A.M.; Garretsen, H.F.L.

2015-01-01

Engagement is a determinant of how well a person will respond to professional input. This study investigates whether, in practice, routinely measured data predict initial client engagement with community mental health services. Engagement, problem severity, client characteristics, and duration

Clinical assessment scoring system for tracheostomy (CASST) criterion: Objective criteria to predict pre-operatively the need for a tracheostomy in head and neck malignancies.

Science.gov (United States)

Gupta, Karan; Mandlik, Dushyant; Patel, Daxesh; Patel, Purvi; Shah, Bankim; Vijay, Devanhalli G; Kothari, Jagdish M; Toprani, Rajendra B; Patel, Kaustubh D

2016-09-01

Tracheostomy is a mainstay modality for airway management for patients with head-neck cancer undergoing surgery. This study aims to define factors predicting need of tracheostomy and define an effective objective criterion to predict tracheostomy need. 486 patients undergoing composite resections were studied. Factors analyzed were age, previous surgery, extent of surgery, trismus, extent of mandibular resection and reconstruction etc. Factors were divided into major and minor, using the clinical assessment scoring system for tracheostomy (CASST) criterion. Sixty seven (13.7%) patients required tracheostomy for their peri-operative management. Elective tracheostomies were done in 53 cases during surgery and post-operatively in 14 patients. All patients in whom tracheostomies were anticipated had a score of seven or more. A decision on whether or not an elective tracheotomy in head and neck surgery is necessary and can be facilitated using CASST criterion, which has a sensitivity of 95.5% and a negative predictive value (NPV) of 99.3%. It may reduce post-operative complications and contribute to safer treatment. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

A phenomenological prediction of dryout based on the churn-to-annular flow transition criterion in uniformly heated vertical tubes

International Nuclear Information System (INIS)

Hong, Sung-Deok; Chun, Se-Young; Yang, Sun-Kyu; Chung, Moon-Ki; Lashgari, Farbod

2000-01-01

A phenomenological model is proposed to predict dryout in uniformly heated vertical tubes. The major point of the study was refining the initial conditions at the onset of annular flow location that starts the liquid film dryout process. The void fraction at the onset of the annular flow location has been derived from the vapor superficial velocity obtained by the churn-to-annular flow criterion with the help of the void-quality relationship. The thermodynamic equilibrium quality calculated through the iteration of flow quality using the profile-fit model to find the accurate starting point of the annular-flow in a tube. The present method was validated by worldwide data covering wide parametric ranges, a diameter of 5.1-37.5, exit quality over 10%, a flow rate of 183-5261 kg/m 2 -s and a system pressure of 0.5-17.7 MPa. The churn-to-annular flow transition criterion of Taitel et al.'s shows better prediction results than the other transition criteria. The present model improved the CHF prediction capability as a mean of 0.97 and root mean square error of 11% for the 3883 experimental data and extended the applicable range to the relatively low quality region. (author)

Health Communication in Social Media: Message Features Predicting User Engagement on Diabetes-Related Facebook Pages.

Science.gov (United States)

Rus, Holly M; Cameron, Linda D

2016-10-01

Social media provides unprecedented opportunities for enhancing health communication and health care, including self-management of chronic conditions such as diabetes. Creating messages that engage users is critical for enhancing message impact and dissemination. This study analyzed health communications within ten diabetes-related Facebook pages to identify message features predictive of user engagement. The Common-Sense Model of Illness Self-Regulation and established health communication techniques guided content analyses of 500 Facebook posts. Each post was coded for message features predicted to engage users and numbers of likes, shares, and comments during the week following posting. Multi-level, negative binomial regressions revealed that specific features predicted different forms of engagement. Imagery emerged as a strong predictor; messages with images had higher rates of liking and sharing relative to messages without images. Diabetes consequence information and positive identity predicted higher sharing while negative affect, social support, and crowdsourcing predicted higher commenting. Negative affect, crowdsourcing, and use of external links predicted lower sharing while positive identity predicted lower commenting. The presence of imagery weakened or reversed the positive relationships of several message features with engagement. Diabetes control information and negative affect predicted more likes in text-only messages, but fewer likes when these messages included illustrative imagery. Similar patterns of imagery's attenuating effects emerged for the positive relationships of consequence information, control information, and positive identity with shares and for positive relationships of negative affect and social support with comments. These findings hold promise for guiding communication design in health-related social media.

Role of optimization criterion in static asymmetric analysis of lumbar spine load.

Science.gov (United States)

Daniel, Matej

2011-10-01

A common method for load estimation in biomechanics is the inverse dynamics optimization, where the muscle activation pattern is found by minimizing or maximizing the optimization criterion. It has been shown that various optimization criteria predict remarkably similar muscle activation pattern and intra-articular contact forces during leg motion. The aim of this paper is to study the effect of the choice of optimization criterion on L4/L5 loading during static asymmetric loading. Upright standing with weight in one stretched arm was taken as a representative position. Musculoskeletal model of lumbar spine model was created from CT images of Visible Human Project. Several criteria were tested based on the minimization of muscle forces, muscle stresses, and spinal load. All criteria provide the same level of lumbar spine loading (difference is below 25%), except the criterion of minimum lumbar shear force which predicts unrealistically high spinal load and should not be considered further. Estimated spinal load and predicted muscle force activation pattern are in accordance with the intradiscal pressure measurements and EMG measurements. The L4/L5 spine loads 1312 N, 1674 N, and 1993 N were predicted for mass of weight in hand 2, 5, and 8 kg, respectively using criterion of mininum muscle stress cubed. As the optimization criteria do not considerably affect the spinal load, their choice is not critical in further clinical or ergonomic studies and computationally simpler criterion can be used.

Use of the Niyama criterion to predict porosity of the mushy zone with deformation

Directory of Open Access Journals (Sweden)

S. Polyakov

2011-10-01

Full Text Available The article presents new results on the use of the Niyama criterion to estimate porosity appearance in castings under hindered shrinkage. The effect of deformation of the mushy zone on filtration is shown. A new form of the Niyama criterion accounting for the hindered shrinkage and the range of deformation localization has been obtained. The results of this study are illustrated by the examp le of the Niyama criterion calculated for Al-Cu alloys under different diffusion conditions of solidification and rate of deformation in the mushy zone. Derived equations can be used in a mathematical model of the casting solidification as well as for interpretation of the simulation results of casting solidification under hindered shrinkage. The presented study resulted in a new procedure of using the Niyama criterion under mushy zone deformation.

Shrinkage Porosity Criterion and Its Application to A 5.5 Ton Steel Ingot

Directory of Open Access Journals (Sweden)

Zhang C.

2016-06-01

Full Text Available In order to predict the distribution of shrinkage porosity in steel ingot efficiently and accurately, a criterion R√L and a method to obtain its threshold value were proposed. The criterion R√L was derived based on the solidification characteristics of steel ingot and pressure gradient in the mushy zone, in which the physical properties, the thermal parameters, the structure of the mushy zone and the secondary dendrite arm spacing were all taken into consideration. The threshold value of the criterion R√L was obtained with combination of numerical simulation of ingot solidification and total solidification shrinkage rate. Prediction of the shrinkage porosity in a 5.5 ton ingot of 2Cr13 steel with criterion R√L>0.21 m · °C1/2 · s−3/2 agreed well with the results of experimental sectioning. Based on this criterion, optimization of the ingot was carried out by decreasing the height-to-diameter ratio and increasing the taper, which successfully eliminated the centreline porosity and further proved the applicability of this criterion.

A simple stability criterion for CANDU figure-of-eight flow oscillations

International Nuclear Information System (INIS)

Gulshani, P.; Spinks, N.J.

1983-01-01

Potential flow oscillations in CANDU reactor primary heat transport system are analyzed in terms of a simple, linearized model. A simple, algebraic stability criterion is obtained. The model predictions are found to be in good agreement with those of thermohydraulic codes for high pressure natural circulation conditions. For normal operating conditions the criterion predicts the correct trend but overlooks important stabilizing effects. The model clarifies the instability mechanism; namely the response of enthalpy and, hence, pressure in the boiling region to flow change

Nonparametric adaptive age replacement with a one-cycle criterion

International Nuclear Information System (INIS)

Coolen-Schrijner, P.; Coolen, F.P.A.

2007-01-01

Age replacement of technical units has received much attention in the reliability literature over the last four decades. Mostly, the failure time distribution for the units is assumed to be known, and minimal costs per unit of time is used as optimality criterion, where renewal reward theory simplifies the mathematics involved but requires the assumption that the same process and replacement strategy continues over a very large ('infinite') period of time. Recently, there has been increasing attention to adaptive strategies for age replacement, taking into account the information from the process. Although renewal reward theory can still be used to provide an intuitively and mathematically attractive optimality criterion, it is more logical to use minimal costs per unit of time over a single cycle as optimality criterion for adaptive age replacement. In this paper, we first show that in the classical age replacement setting, with known failure time distribution with increasing hazard rate, the one-cycle criterion leads to earlier replacement than the renewal reward criterion. Thereafter, we present adaptive age replacement with a one-cycle criterion within the nonparametric predictive inferential framework. We study the performance of this approach via simulations, which are also used for comparisons with the use of the renewal reward criterion within the same statistical framework

Genetic Gain Increases by Applying the Usefulness Criterion with Improved Variance Prediction in Selection of Crosses.

Science.gov (United States)

Lehermeier, Christina; Teyssèdre, Simon; Schön, Chris-Carolin

2017-12-01

A crucial step in plant breeding is the selection and combination of parents to form new crosses. Genome-based prediction guides the selection of high-performing parental lines in many crop breeding programs which ensures a high mean performance of progeny. To warrant maximum selection progress, a new cross should also provide a large progeny variance. The usefulness concept as measure of the gain that can be obtained from a specific cross accounts for variation in progeny variance. Here, it is shown that genetic gain can be considerably increased when crosses are selected based on their genomic usefulness criterion compared to selection based on mean genomic estimated breeding values. An efficient and improved method to predict the genetic variance of a cross based on Markov chain Monte Carlo samples of marker effects from a whole-genome regression model is suggested. In simulations representing selection procedures in crop breeding programs, the performance of this novel approach is compared with existing methods, like selection based on mean genomic estimated breeding values and optimal haploid values. In all cases, higher genetic gain was obtained compared with previously suggested methods. When 1% of progenies per cross were selected, the genetic gain based on the estimated usefulness criterion increased by 0.14 genetic standard deviation compared to a selection based on mean genomic estimated breeding values. Analytical derivations of the progeny genotypic variance-covariance matrix based on parental genotypes and genetic map information make simulations of progeny dispensable, and allow fast implementation in large-scale breeding programs. Copyright © 2017 by the Genetics Society of America.

Facial motion engages predictive visual mechanisms.

Directory of Open Access Journals (Sweden)

Jordy Kaufman

Full Text Available We employed a novel cuing paradigm to assess whether dynamically versus statically presented facial expressions differentially engaged predictive visual mechanisms. Participants were presented with a cueing stimulus that was either the static depiction of a low intensity expressed emotion; or a dynamic sequence evolving from a neutral expression to the low intensity expressed emotion. Following this cue and a backwards mask, participants were presented with a probe face that displayed either the same emotion (congruent or a different emotion (incongruent with respect to that displayed by the cue although expressed at a high intensity. The probe face had either the same or different identity from the cued face. The participants' task was to indicate whether or not the probe face showed the same emotion as the cue. Dynamic cues and same identity cues both led to a greater tendency towards congruent responding, although these factors did not interact. Facial motion also led to faster responding when the probe face was emotionally congruent to the cue. We interpret these results as indicating that dynamic facial displays preferentially invoke predictive visual mechanisms, and suggest that motoric simulation may provide an important basis for the generation of predictions in the visual system.

LSSVM-Based Rock Failure Criterion and Its Application in Numerical Simulation

Directory of Open Access Journals (Sweden)

Changxing Zhu

2015-01-01

Full Text Available A rock failure criterion is very important for the prediction of the failure of rocks or rock masses in rock mechanics and engineering. Least squares support vector machines (LSSVM are a powerful tool for addressing complex nonlinear problems. This paper describes a LSSVM-based rock failure criterion for analyzing the deformation of a circular tunnel under different in situ stresses without assuming a function form. First, LSSVM was used to represent the nonlinear relationship between the mechanical properties of rock and the failure behavior of the rock in order to construct a rock failure criterion based on experimental data. Then, this was used in a hypothetical numerical analysis of a circular tunnel to analyze the mechanical behavior of the rock mass surrounding the tunnel. The Mohr-Coulomb and Hoek-Brown failure criteria were also used to analyze the same case, and the results were compared; these clearly indicate that LSSVM can be used to establish a rock failure criterion and to predict the failure of a rock mass during excavation of a circular tunnel.

The Brand's PREACH Model: Predicting Readiness to Engage African American Churches in Health.

Science.gov (United States)

Brand, Dorine J; Alston, Reginald J

2017-09-01

Despite many attempts to reduce health disparities, health professionals face obstacles in improving poor health outcomes within the African American (AA) community. To promote change for improved health measures, it is important to implement culturally tailored programming through a trusted institution, such as the AA church. While churches have the potential to play an important role in positively impacting health among AAs, it is unclear what attributes are necessary to predict success or failure for health promotion within these institutions. The purpose of this study was to create a model, the Brand's PREACH ( Predicting Readiness to Engage African American Churches in Health) Model, to predict the readiness of AA churches to engage in health promotion programming. Thirty-six semistructured key informant interviews were conducted with 12 pastors, 12 health leaders, and 12 congregants to gain information on the relationship between church infrastructure (physical structure, personnel, funding, and social/cultural support), readiness, and health promotion programming. The findings revealed that church infrastructure has an association with and will predict the readiness of a church to engage in health promotion programming. The ability to identify readiness early on will be useful for developing, implementing, and evaluating faith-based interventions, in partnership with churches, which is a key factor for sustainable and effective programs.

Social interaction anxiety and personality traits predicting engagement in health risk sexual behaviors.

Science.gov (United States)

Rahm-Knigge, Ryan L; Prince, Mark A; Conner, Bradley T

2018-06-01

Individuals with social interaction anxiety, a facet of social anxiety disorder, withdraw from or avoid social encounters and generally avoid risks. However, a subset engages in health risk sexual behavior (HRSB). Because sensation seeking, emotion dysregulation, and impulsivity predict engagement in HRSB among adolescents and young adults, the present study hypothesized that latent classes of social interaction anxiety and these personality traits would differentially predict likelihood of engagement in HRSB. Finite mixture modeling was used to discern four classes: two low social interaction anxiety classes distinguished by facets of emotion dysregulation, positive urgency, and negative urgency (Low SIAS High Urgency and Low SIAS Low Urgency) and two high social interaction anxiety classes distinguished by positive urgency, negative urgency, risk seeking, and facets of emotion dysregulation (High SIAS High Urgency and High SIAS Low Urgency). HRSB were entered into the model as auxiliary distal outcomes. Of importance to this study were findings that the High SIAS High Urgency class was more likely to engage in most identified HRSB than the High SIAS Low Urgency class. This study extends previous findings on the heterogeneity of social interaction anxiety by identifying the effects of social interaction anxiety and personality on engagement in HRSB. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Distributed Criterion Design

Science.gov (United States)

McDougall, Dennis

2006-01-01

This article describes and illustrates a novel form of the changing criterion design called the distributed criterion design, which represents perhaps the first advance in the changing criterion design in four decades. The distributed criterion design incorporates elements of the multiple baseline and A-B-A-B designs and is well suited to applied…

A New Multiaxial High-Cycle Fatigue Criterion Based on the Critical Plane for Ductile and Brittle Materials

Science.gov (United States)

Wang, Cong; Shang, De-Guang; Wang, Xiao-Wei

2015-02-01

An improved high-cycle multiaxial fatigue criterion based on the critical plane was proposed in this paper. The critical plane was defined as the plane of maximum shear stress (MSS) in the proposed multiaxial fatigue criterion, which is different from the traditional critical plane based on the MSS amplitude. The proposed criterion was extended as a fatigue life prediction model that can be applicable for ductile and brittle materials. The fatigue life prediction model based on the proposed high-cycle multiaxial fatigue criterion was validated with experimental results obtained from the test of 7075-T651 aluminum alloy and some references.

On the Jeans criterion

International Nuclear Information System (INIS)

Whitworth, A.P.

1980-01-01

The Jeans criterion is first stated and distinguished from the Virial Theorem. Then it is discussed how the Jeans criterion can be derived from the Virial Theorem and the inherent shortcomings in this derivation. Finally, it is indicated how these shortcomings might be overcome. The Jeans criterion is a fragmentation - or condensation -criterion. An expression is given, connecting the fragmentation of an unstable extended medium into masses Msub(J). Rather than picturing the background medium fragmenting, it is probably more appropriate to envisage these masses Msub(J) 'condensing' out of the background medium. On the condensation picture some fraction of the background material separates out into coherent bound nodules under the pull of its self-gravity. For this reason the Jeans criterion is discussed as a condensation condition, reserving the term fragmentation for a different process. The Virial Theorem provides a contraction criterion. This is described with reference to a spherical cloud and is developed to derive the Jeans criterion. (U.K.)

Do workaholism and work engagement predict employee well-being and performance in opposite directions?

Science.gov (United States)

Shimazu, Akihito; Schaufeli, Wilmar B; Kubota, Kazumi; Kawakami, Norito

2012-01-01

This study investigated the distinctiveness between workaholism and work engagement by examining their longitudinal relationships (measurement interval=7 months) with well-being and performance in a sample of 1,967 Japanese employees from various occupations. Based on a previous cross-sectional study (Shimazu & Schaufeli, 2009), we expected that workaholism predicts future unwell-being (i.e., high ill-health and low life satisfaction) and poor job performance, whereas work engagement predicts future well-being (i.e., low ill-health and high life satisfaction) and superior job performance. T1-T2 changes in ill-health, life satisfaction and job performance were measured as residual scores that were then included in the structural equation model. Results showed that workaholism and work engagement were weakly and positively related to each other. In addition, workaholism was related to an increase in ill-health and to a decrease in life satisfaction. In contrast, work engagement was related to a decrease in ill-health and to increases in both life satisfaction and job performance. These findings suggest that workaholism and work engagement are two different kinds of concepts that are oppositely related to well-being and performance.

Beyond size : Predicting engagement in environmental management practices of Dutch SMEs

NARCIS (Netherlands)

Uhlaner, L.M.; Berent-Braun, M.M.; Jeurissen, R.J.M.; Wit, de G.

2012-01-01

This study focuses on the prediction of the engagement of small- and medium-sized enterprises (SMEs) in environmental management practices, based on a random sample of 689 SMEs. The study finds that several endogenous factors, including tangibility of sector, firm size, innovative orientation,

Forming limit prediction by an evolving non-quadratic yield criterion considering the anisotropic hardening and r-value evolution

Science.gov (United States)

Lian, Junhe; Shen, Fuhui; Liu, Wenqi; Münstermann, Sebastian

2018-05-01

The constitutive model development has been driven to a very accurate and fine-resolution description of the material behaviour responding to various environmental variable changes. The evolving features of the anisotropic behaviour during deformation, therefore, has drawn particular attention due to its possible impacts on the sheet metal forming industry. An evolving non-associated Hill48 (enHill48) model was recently proposed and applied to the forming limit prediction by coupling with the modified maximum force criterion. On the one hand, the study showed the significance to include the anisotropic evolution for accurate forming limit prediction. On the other hand, it also illustrated that the enHill48 model introduced an instability region that suddenly decreases the formability. Therefore, in this study, an alternative model that is based on the associated flow rule and provides similar anisotropic predictive capability is extended to chapter the evolving effects and further applied to the forming limit prediction. The final results are compared with experimental data as well as the results by enHill48 model.

Ductile failure analysis of API X65 pipes with notch-type defects using a local fracture criterion

International Nuclear Information System (INIS)

Oh, Chang-Kyun; Kim, Yun-Jae; Baek, Jong-Hyun; Kim, Young-Pyo; Kim, Woo-Sik

2007-01-01

A local failure criterion for API X65 steel is applied to predict ductile failure of full-scale API X65 pipes with simulated corrosion and gouge defects under internal pressure. The local failure criterion is the stress-modified fracture strain as a function of the stress triaxiality (defined by the ratio of the hydrostatic stress to the effective stress). Based on detailed finite element (FE) analyses with the proposed local failure criterion, burst pressures of defective pipes are estimated and compared with experimental data. For pipes with simulated corrosion defects, FE analysis with the proposed local fracture criterion indicates that predicted failure takes place after the defective pipes attain maximum loads for all cases, possibly due to the fact that the material has sufficient ductility. For pipes with simulated gouge defects, on the other hand, it is found that predicted failure takes place before global instability, and the predicted burst pressures are in good agreement with experimental data, providing confidence in the present approach

Direct numerical simulations of non-premixed ethylene-air flames: Local flame extinction criterion

KAUST Repository

Lecoustre, Vivien R.

2014-11-01

Direct Numerical Simulations (DNS) of ethylene/air diffusion flame extinctions in decaying two-dimensional turbulence were performed. A Damköhler-number-based flame extinction criterion as provided by classical large activation energy asymptotic (AEA) theory is assessed for its validity in predicting flame extinction and compared to one based on Chemical Explosive Mode Analysis (CEMA) of the detailed chemistry. The DNS code solves compressible flow conservation equations using high order finite difference and explicit time integration schemes. The ethylene/air chemistry is simulated with a reduced mechanism that is generated based on the directed relation graph (DRG) based methods along with stiffness removal. The numerical configuration is an ethylene fuel strip embedded in ambient air and exposed to a prescribed decaying turbulent flow field. The emphasis of this study is on the several flame extinction events observed in contrived parametric simulations. A modified viscosity and changing pressure (MVCP) scheme was adopted in order to artificially manipulate the probability of flame extinction. Using MVCP, pressure was changed from the baseline case of 1 atm to 0.1 and 10 atm. In the high pressure MVCP case, the simulated flame is extinction-free, whereas in the low pressure MVCP case, the simulated flame features frequent extinction events and is close to global extinction. Results show that, despite its relative simplicity and provided that the global flame activation temperature is correctly calibrated, the AEA-based flame extinction criterion can accurately predict the simulated flame extinction events. It is also found that the AEA-based criterion provides predictions of flame extinction that are consistent with those provided by a CEMA-based criterion. This study supports the validity of a simple Damköhler-number-based criterion to predict flame extinction in engineering-level CFD models. © 2014 The Combustion Institute.

Rayleigh Number Criterion for Formation of A-Segregates in Steel Castings and Ingots

DEFF Research Database (Denmark)

Rad, M. Torabi; Kotas, Petr; Beckermann, C.

2013-01-01

A Rayleigh number-based criterion is developed for predicting the formation of A-segregates in steel castings and ingots. The criterion is calibrated using available experimental data for ingots involving 27 different steel compositions. The critical Rayleigh number above which A-segregates can b......, the primary reason for this over-prediction is persumed to be the presence of a central zone of equiaxed grains in the casting sections. A-segregates do not form when the grain structure is equiaxed. © The Minerals, Metals & Materials Society and ASM International 2013...

An Empirical Model Building Criterion Based on Prediction with Applications in Parametric Cost Estimation.

Science.gov (United States)

1980-08-01

varia- ble is denoted by 7, the total sum of squares of deviations from that mean is defined by n - SSTO - (-Y) (2.6) iul and the regression sum of...squares by SSR - SSTO - SSE (2.7) II 14 A selection criterion is a rule according to which a certain model out of the 2p possible models is labeled "best...dis- cussed next. 1. The R2 Criterion The coefficient of determination is defined by R2 . 1 - SSE/ SSTO . (2.8) It is clear that R is the proportion of

Generalized Majority Logic Criterion to Analyze the Statistical Strength of S-Boxes

Science.gov (United States)

Hussain, Iqtadar; Shah, Tariq; Gondal, Muhammad Asif; Mahmood, Hasan

2012-05-01

The majority logic criterion is applicable in the evaluation process of substitution boxes used in the advanced encryption standard (AES). The performance of modified or advanced substitution boxes is predicted by processing the results of statistical analysis by the majority logic criteria. In this paper, we use the majority logic criteria to analyze some popular and prevailing substitution boxes used in encryption processes. In particular, the majority logic criterion is applied to AES, affine power affine (APA), Gray, Lui J, residue prime, S8 AES, Skipjack, and Xyi substitution boxes. The majority logic criterion is further extended into a generalized majority logic criterion which has a broader spectrum of analyzing the effectiveness of substitution boxes in image encryption applications. The integral components of the statistical analyses used for the generalized majority logic criterion are derived from results of entropy analysis, contrast analysis, correlation analysis, homogeneity analysis, energy analysis, and mean of absolute deviation (MAD) analysis.

Bell's theorem based on a generalized EPR criterion of reality

International Nuclear Information System (INIS)

Eberhard, P.H.; Rosselet, P.

1995-01-01

First, the demonstration of Bell's theorem, i.e., of the nonlocal character of quantum theory, is spelled out using the EPR criterion of reality as premises and a gedanken experiment involving two particles. Then, the EPR criterion is extended to include quantities predicted almost with certainty, and Bell's theorem is demonstrated on these new premises. The same experiment is used but in conditions that become possible in real life, without the requirements of ideal efficiencies and zero background. Very high efficiencies and low background are needed, but these requirements may be met in the future

A new self-report inventory of dyslexia for students: criterion and construct validity.

Science.gov (United States)

Tamboer, Peter; Vorst, Harrie C M

2015-02-01

The validity of a Dutch self-report inventory of dyslexia was ascertained in two samples of students. Six biographical questions, 20 general language statements and 56 specific language statements were based on dyslexia as a multi-dimensional deficit. Dyslexia and non-dyslexia were assessed with two criteria: identification with test results (Sample 1) and classification using biographical information (both samples). Using discriminant analyses, these criteria were predicted with various groups of statements. All together, 11 discriminant functions were used to estimate classification accuracy of the inventory. In Sample 1, 15 statements predicted the test criterion with classification accuracy of 98%, and 18 statements predicted the biographical criterion with classification accuracy of 97%. In Sample 2, 16 statements predicted the biographical criterion with classification accuracy of 94%. Estimations of positive and negative predictive value were 89% and 99%. Items of various discriminant functions were factor analysed to find characteristic difficulties of students with dyslexia, resulting in a five-factor structure in Sample 1 and a four-factor structure in Sample 2. Answer bias was investigated with measures of internal consistency reliability. Less than 20 self-report items are sufficient to accurately classify students with and without dyslexia. This supports the usefulness of self-assessment of dyslexia as a valid alternative to diagnostic test batteries. Copyright © 2015 John Wiley & Sons, Ltd.

An Elasto-Plastic Damage Model for Rocks Based on a New Nonlinear Strength Criterion

Science.gov (United States)

Huang, Jingqi; Zhao, Mi; Du, Xiuli; Dai, Feng; Ma, Chao; Liu, Jingbo

2018-05-01

The strength and deformation characteristics of rocks are the most important mechanical properties for rock engineering constructions. A new nonlinear strength criterion is developed for rocks by combining the Hoek-Brown (HB) criterion and the nonlinear unified strength criterion (NUSC). The proposed criterion takes account of the intermediate principal stress effect against HB criterion, as well as being nonlinear in the meridian plane against NUSC. Only three parameters are required to be determined by experiments, including the two HB parameters σ c and m i . The failure surface of the proposed criterion is continuous, smooth and convex. The proposed criterion fits the true triaxial test data well and performs better than the other three existing criteria. Then, by introducing the Geological Strength Index, the proposed criterion is extended to rock masses and predicts the test data well. Finally, based on the proposed criterion, a triaxial elasto-plastic damage model for intact rock is developed. The plastic part is based on the effective stress, whose yield function is developed by the proposed criterion. For the damage part, the evolution function is assumed to have an exponential form. The performance of the constitutive model shows good agreement with the results of experimental tests.

[GSH fermentation process modeling using entropy-criterion based RBF neural network model].

Science.gov (United States)

Tan, Zuoping; Wang, Shitong; Deng, Zhaohong; Du, Guocheng

2008-05-01

The prediction accuracy and generalization of GSH fermentation process modeling are often deteriorated by noise existing in the corresponding experimental data. In order to avoid this problem, we present a novel RBF neural network modeling approach based on entropy criterion. It considers the whole distribution structure of the training data set in the parameter learning process compared with the traditional MSE-criterion based parameter learning, and thus effectively avoids the weak generalization and over-learning. Then the proposed approach is applied to the GSH fermentation process modeling. Our results demonstrate that this proposed method has better prediction accuracy, generalization and robustness such that it offers a potential application merit for the GSH fermentation process modeling.

Bell's theorem based on a generalized EPR criterion of reality

International Nuclear Information System (INIS)

Eberhard, P.H.; Rosselet, P.

1993-04-01

First, the demonstration of Bell's theorem, i.e. of the non-local character of quantum theory, is spelled out using the EPR criterion of reality as premises and a gedanken experiment involving two particles. Then, the EPR criterion is extended to include quantities predicted almost with certainty, and Bell's theorem is demonstrated on these new premises. The same experiment is used but in conditions that become possible in real life, without the requirements of ideal efficiencies and zero background. Very high efficiencies and low background are needed, but these requirements may be met in the future. (author) 1 fig., 11 refs

On translational superfluidity and the Landau criterion for Bose gases in the Gross-Pitaevski limit

International Nuclear Information System (INIS)

Wreszinski, Walter F

2008-01-01

The two-fluid and Landau criteria for superfluidity are compared for trapped Bose gases. While the two-fluid criterion predicts translational superfluidity, it is suggested, on the basis of the homogeneous Gross-Pitaevski limit, that a necessary part of Landau's criterion, adequate for non-translationally invariant systems, does not hold for trapped Bose gases in the GP limit. As a consequence, if the compressibility is detected to be very large (infinite by experimental standards), the two-fluid criterion is seen to be the relevant one in case the system is a translational superfluid, while the Landau criterion is the relevant one if translational superfluidity is absent. (fast track communication)

Beyond Engagement Analytics: Which Online Mixed-Data Factors Predict Student Learning Outcomes?

Science.gov (United States)

Strang, Kenneth David

2017-01-01

This mixed-method study focuses on online learning analytics, a research area of importance. Several important student attributes and their online activities are examined to identify what seems to work best to predict higher grades. The purpose is to explore the relationships between student grade and key learning engagement factors using a large…

Discriminant Validity Assessment: Use of Fornell & Larcker criterion versus HTMT Criterion

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Hamid, M. R. Ab; Sami, W.; Mohmad Sidek, M. H.

2017-09-01

Assessment of discriminant validity is a must in any research that involves latent variables for the prevention of multicollinearity issues. Fornell and Larcker criterion is the most widely used method for this purpose. However, a new method has emerged for establishing the discriminant validity assessment through heterotrait-monotrait (HTMT) ratio of correlations method. Therefore, this article presents the results of discriminant validity assessment using these methods. Data from previous study was used that involved 429 respondents for empirical validation of value-based excellence model in higher education institutions (HEI) in Malaysia. From the analysis, the convergent, divergent and discriminant validity were established and admissible using Fornell and Larcker criterion. However, the discriminant validity is an issue when employing the HTMT criterion. This shows that the latent variables under study faced the issue of multicollinearity and should be looked into for further details. This also implied that the HTMT criterion is a stringent measure that could detect the possible indiscriminant among the latent variables. In conclusion, the instrument which consisted of six latent variables was still lacking in terms of discriminant validity and should be explored further.

Time to Criterion: An Experimental Study.

Science.gov (United States)

Anderson, Lorin W.

The purpose of the study was to investigate the magnitude of individual differences in time-to-criterion and the stability of these differences. Time-to-criterion was defined in two ways: the amount of elapsed time required to attain the criterion level and the amount of on-task time required to attain the criterion level. Ninety students were…

How personal resources predict work engagement and self-rated performance among construction workers: a social cognitive perspective.

Science.gov (United States)

Lorente, Laura; Salanova, Marisa; Martínez, Isabel M; Vera, María

2014-06-01

Traditionally, research focussing on psychosocial factors in the construction industry has focused mainly on the negative aspects of health and on results such as occupational accidents. This study, however, focuses on the specific relationships among the different positive psychosocial factors shared by construction workers that could be responsible for occupational well-being and outcomes such as performance. The main objective of this study was to test whether personal resources predict self-rated job performance through job resources and work engagement. Following the predictions of Bandura's Social Cognitive Theory and the motivational process of the Job Demands-Resources Model, we expect that the relationship between personal resources and performance will be fully mediated by job resources and work engagement. The sample consists of 228 construction workers. Structural equation modelling supports the research model. Personal resources (i.e. self-efficacy, mental and emotional competences) play a predicting role in the perception of job resources (i.e. job control and supervisor social support), which in turn leads to work engagement and self-rated performance. This study emphasises the crucial role that personal resources play in determining how people perceive job resources by determining the levels of work engagement and, hence, their self-rated job performance. Theoretical and practical implications are discussed. © 2014 International Union of Psychological Science.

Ten Issues in Criterion-Referenced Testing: A Response to Commonly Heard Criticisms.

Science.gov (United States)

Curlette, William L.; Stallings, William M.

1979-01-01

The 10 criticisms of criterion-referenced tests addressed in this paper are: the domains tested; pedagogical influence; difficulty of items; cumbersome reports; reliability; arbitrary criteria; local objectives; labeling; predictive validity; and repeated testing. (SJL)

A study on the instability criterion for the stratified flow in horizontal pipe at cocurrent flow conditions

Energy Technology Data Exchange (ETDEWEB)

Sung, Chang Kyung [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

1998-12-31

This paper presents a theoretical approach of the instability criterion from stratified to nonstratified flow in horizontal pipe at cocurrent flow conditions. The new theoretical instability criterion for the stratified and nonstratified flow transition in horizontal pipe has been developed by hyperbolic equations in two-phase flow. Critical flow condition criterion and onset of slugging at cocurrent flow condition correspond to zero and imaginary characteristics which occur when the hyperbolicity of a stratified two-phase flow is broken, respectively. Through comparison between results predicted by the present flow is broken, respectively. Through comparison between results predicted by the present theory and the Kukita et al. [1] experimental data of pipes, it is shown that they are in good agreement with data. 4 refs., 2 figs. (Author)

A study on the instability criterion for the stratified flow in horizontal pipe at cocurrent flow conditions

Energy Technology Data Exchange (ETDEWEB)

Sung, Chang Kyung [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

1997-12-31

This paper presents a theoretical approach of the instability criterion from stratified to nonstratified flow in horizontal pipe at cocurrent flow conditions. The new theoretical instability criterion for the stratified and nonstratified flow transition in horizontal pipe has been developed by hyperbolic equations in two-phase flow. Critical flow condition criterion and onset of slugging at cocurrent flow condition correspond to zero and imaginary characteristics which occur when the hyperbolicity of a stratified two-phase flow is broken, respectively. Through comparison between results predicted by the present flow is broken, respectively. Through comparison between results predicted by the present theory and the Kukita et al. [1] experimental data of pipes, it is shown that they are in good agreement with data. 4 refs., 2 figs. (Author)

Applicability of the Modified Ritchie-Knott-Rice Failure Criterion to Examine the Feasibility of Miniaturized Charpy Type SE(B Specimens

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Toshiyuki Meshii

2016-01-01

Full Text Available This paper examined whether the modified Ritchie-Knott-Rice (RKR failure criterion can be applied to examine the feasibility of miniaturized Charpy type SE(B specimens of thickness-to-width ratio B/W=1. The modified RKR failure criterion considered in this paper is the (4δt,σ22c criterion which predicts the onset of cleavage fracture when the midplane crack-opening stress measured at a distance equal to four times the crack-tip opening displacement, denoted as σ22d, exceeds a critical stress σ22c. Specimens with B values of 25, 10, 3, and 2 mm (denoted as 25t, 10t, 3t, and 2t specimens, resp. manufactured with 0.55% carbon steel were tested at 20°C. The results showed that the modified RKR criterion could appropriately predict the occurrence of cleavage fracture accompanied by negligibly small stable crack extension (denoted as KJc fracture naturally for the 25t and 10t specimens. The modified RKR criterion could also predict that KJc fracture does not occur for the 2t specimen. The σ22c obtained from specimens for the 25t and 10t specimens exhibited only a small difference, indicating that the Jc obtained from the 10t specimens can be used to predict the Jc that will be obtained with the 25t specimens.

Predicting drive for muscularity behavioural engagement from body image attitudes and emotions.

Science.gov (United States)

Tod, David; Edwards, Christian

2013-01-01

We examined the potential moderating effects of appearance investment, body image disturbance, and situational body image dysphoria on the drive for muscularity attitude-behaviour relationship. Participants (339 British college men, M(AGE)=20.00 years, SD=2.59) completed drive for muscularity attitude and behaviour, appearance investment, body image disturbance, and situational body image dysphoria measures. Results indicated higher levels of appearance investment, body image disturbance, and situational body image dysphoria were associated with increases in the drive for muscularity attitude's relationship with physique-enhancing behavioural engagement. Results help extend recent research that has moved beyond identifying correlates to examining ways that groups of variables interact to predict drive for muscularity behavioural engagement and may contribute to theory development. Copyright © 2012 Elsevier Ltd. All rights reserved.

Mediating role of work engagement in the relationship between job resources and personal resources with turnover intention among female nurses.

Science.gov (United States)

Shahpouri, Samira; Namdari, Kourosh; Abedi, Ahmad

2016-05-01

One of the latest models proposed with regard to work engagement is the detailed model put forward by Bakker and Demerouti (2007). The present study aims at investigating the effect of job resources and personal resources on turnover intention with the mediator role of work engagement among female nurses at Isfahan Alzahra Hospital. In the current study, job and personal resources were considered as the predictors of job turnover and work engagement was considered as the mediator variable among predictive and criterion variables. The data of the present study were collected from 208 female nurses who were selected by systematic random sampling. As for the analysis of the collected data, structural equations model, normal distribution method, and Bootstrap method in Macro, Preacher and Hayes, (2004) program were deployed. The findings showed that the personal resources affect the turnover intention both directly and indirectly (through work engagement); however, job resources are just associated with turnover intention with the mediating role of work engagement. The results of the study have important implications for organizations' managers about improving work engagement. Copyright © 2015 Elsevier Inc. All rights reserved.

Extensions and applications of the Bohm criterion

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Baalrud, Scott D.; Scheiner, Brett; Yee, Benjamin; Hopkins, Matthew; Barnat, Edward

2015-04-01

The generalized Bohm criterion is revisited in the context of incorporating kinetic effects of the electron and ion distribution functions into the theory. The underlying assumptions and results of two different approaches are compared: the conventional ‘kinetic Bohm criterion’ and a fluid-moment hierarchy approach. The former is based on the asymptotic limit of an infinitely thin sheath (λD/l = 0), whereas the latter is based on a perturbative expansion of a sheath that is thin compared to the plasma (λD/l ≪ 1). Here λD is the Debye length, which characterizes the sheath length scale, and l is a measure of the plasma or presheath length scale. The consequences of these assumptions are discussed in terms of how they restrict the class of distribution functions to which the resulting criteria can be applied. Two examples are considered to provide concrete comparisons between the two approaches. The first is a Tonks-Langmuir model including a warm ion source (Robertson 2009 Phys. Plasmas 16 103503). This highlights a substantial difference between the conventional kinetic theory, which predicts slow ions dominate at the sheath edge, and the fluid moment approach, which predicts slow ions have little influence. The second example considers planar electrostatic probes biased near the plasma potential using model equations and particle-in-cell simulations. This demonstrates a situation where electron kinetic effects alter the Bohm criterion, leading to a subsonic ion flow at the sheath edge.

Nucleation of recrystallization in fine-grained materials: an extension of the Bailey-Hirsch criterion

Science.gov (United States)

Favre, Julien; Fabrègue, Damien; Chiba, Akihiko; Bréchet, Yves

2013-11-01

A new criterion for nucleation in the case of dynamic recrystallization is proposed in order to include the contribution of the grain boundary energy stored in the microstructure in the energy balance. Due to the nucleation events, the total surface area of pre-existing grain boundaries decreases, leading to a nucleus size smaller than expected by conventional nucleation criteria. The new model provides a better prediction of the nucleus size during recrystallization of pure copper compared with the conventional nucleation criterion.

Do burnout and work engagement predict depressive symptoms and life satisfaction? A three-wave seven-year prospective study.

Science.gov (United States)

Hakanen, Jari J; Schaufeli, Wilmar B

2012-12-10

Burnout and work engagement have been viewed as opposite, yet distinct states of employee well-being. We investigated whether work-related indicators of well-being (i.e. burnout and work engagement) spill-over and generalize to context-free well-being (i.e. depressive symptoms and life satisfaction). More specifically, we examined the causal direction: does burnout/work engagement lead to depressive symptoms/life satisfaction, or the other way around? Three surveys were conducted. In 2003, 71% of all Finnish dentists were surveyed (n=3255), and the response rate of the 3-year follow-up was 84% (n=2555). The second follow-up was conducted four years later with a response rate of 86% (n=1964). Structural equation modeling was used to investigate the cross-lagged associations between the study variables across time. Burnout predicted depressive symptoms and life dissatisfaction from T1 to T2 and from T2 to T3. Conversely, work engagement had a negative effect on depressive symptoms and a positive effect on life satisfaction, both from T1 to T2 and from T2 to T3, even after adjusting for the impact of burnout at every occasion. The study was conducted among one occupational group, which limits its generalizability. Work-related well-being predicts general wellbeing in the long-term. For example, burnout predicts depressive symptoms and not vice versa. In addition, burnout and work engagement are not direct opposites. Instead, both have unique, incremental impacts on life satisfaction and depressive symptoms. Copyright © 2012 Elsevier B.V. All rights reserved.

Electricity Consumption Forecasting Scheme via Improved LSSVM with Maximum Correntropy Criterion

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Jiandong Duan

2018-02-01

Full Text Available In recent years, with the deepening of China’s electricity sales side reform and electricity market opening up gradually, the forecasting of electricity consumption (FoEC becomes an extremely important technique for the electricity market. At present, how to forecast the electricity accurately and make an evaluation of results scientifically are still key research topics. In this paper, we propose a novel prediction scheme based on the least-square support vector machine (LSSVM model with a maximum correntropy criterion (MCC to forecast the electricity consumption (EC. Firstly, the electricity characteristics of various industries are analyzed to determine the factors that mainly affect the changes in electricity, such as the gross domestic product (GDP, temperature, and so on. Secondly, according to the statistics of the status quo of the small sample data, the LSSVM model is employed as the prediction model. In order to optimize the parameters of the LSSVM model, we further use the local similarity function MCC as the evaluation criterion. Thirdly, we employ the K-fold cross-validation and grid searching methods to improve the learning ability. In the experiments, we have used the EC data of Shaanxi Province in China to evaluate the proposed prediction scheme, and the results show that the proposed prediction scheme outperforms the method based on the traditional LSSVM model.

The Bohm criterion for rf discharges

International Nuclear Information System (INIS)

Meijer, P.M.; Goedheer, W.J.

1991-01-01

The well-known dc Bohm criterion is extended to rf discharges. Both low- (ω rf much-lt ω pi ) and high-(ω pi much-lt ω rf ) frequency regimes are considered. For low frequencies, the dc Bohm criterion holds. This criterion states that the initial energy of the ions entering the sheath must exceed a limit in order to obtain a stable sheath. For high frequencies, a modified limit is derived, which is somewhat lower than that of the dc Bohm criterion. The resulting ion current density in a high-frequency sheath is only a few percent lower than that for the dc case

Stigma Predicts Treatment Preferences and Care Engagement among Veterans Affairs Primary Care Patients with Depression

Science.gov (United States)

Campbell, Duncan G.; Bonner, Laura M.; Bolkan, Cory R.; Lanto, Andrew B.; Zivin, Kara; Waltz, Thomas J.; Klap, Ruth; Rubenstein, Lisa V.; Chaney, Edmund F.

2016-01-01

Background Whereas stigma regarding mental health concerns exists, the evidence for stigma as a depression treatment barrier among patients in Veterans Affairs (VA) primary care (PC) is mixed. Purpose To test whether stigma, defined as depression label avoidance, predicted patients' preferences for depression treatment providers, patients' prospective engagement in depression care, and care quality. Methods We conducted cross-sectional and prospective analyses of existing data from 761 VA PC patients with probable major depression. Results Relative to low stigma patients, those with high stigma were less likely to prefer treatment from mental health specialists. In prospective controlled analyses, high stigma predicted lower likelihood of the following: taking medications for mood, treatment by mental health specialists, treatment for emotional concerns in PC, and appropriate depression care. Conclusions High stigma is associated with lower preferences for care from mental health specialists and confers risk for minimal depression treatment engagement. PMID:26935310

Reviewing Employee Turnover: Focusing on Proximal Withdrawal States and an Expanded Criterion

Science.gov (United States)

Hom, Peter W.; Mitchell, Terence R.; Lee, Thomas W.; Griffeth, Rodger W.

2012-01-01

We reconceptualize employee turnover to promote researchers' understanding and prediction of why employees quit or stay in employing institutions. A literature review identifies shortcomings with prevailing turnover dimensions. In response, we expand the conceptual domain of the turnover criterion to include multiple types of turnover (notably,…

Does Self-Determination Predict the School Engagement of Four Different Motivation Types in Adolescence?

Science.gov (United States)

Raufelder, Diana; Regner, Nicola; Drury, Kate; Eid, Michael

2016-01-01

In order to enhance our understanding of inter-individual differences in scholastic motivation, this study examined if self-determination predicts the school engagement of four different motivation types (MT) in a large sample of adolescent students (N = 1088) from Brandenburg, Germany: (1) peer-dependent MT, (2) teacher-dependent MT, (3)…

University student’s engagement: development of the University Student Engagement Inventory (USEI

Directory of Open Access Journals (Sweden)

João Maroco

2016-01-01

Full Text Available Abstract Student engagement is a key factor in academic achievement and degree completion, though there is much debate about the operationalization and dimensionality of this construct. The goal of this paper is to describe the development of an psycho-educational oriented measure – the University Student Engagement Inventory (USEI. This measure draws on the conceptualization of engagement as a multidimensional construct, including cognitive, behavioural and emotional engagement. Participants were 609 Portuguese University students (67 % female majoring in Social Sciences, Biological Sciences or Engineering and Exact Sciences. The content, construct and predictive validity, and reliability of the USEI were tested. The validated USEI was composed of 15 items, and supported the tri-factorial structure of student engagement. We documented evidence of adequate reliability, factorial, convergent and discriminant validities. USEI’s concurrent validity, with the Utrecht Work Engagement Scale-Student Survey, and the predictive validity for self-reported academic achievement and intention to dropout from school were also observed.

Towards chaos criterion in quantum field theory

OpenAIRE

Kuvshinov, V. I.; Kuzmin, A. V.

2002-01-01

Chaos criterion for quantum field theory is proposed. Its correspondence with classical chaos criterion in semi-classical regime is shown. It is demonstrated for real scalar field that proposed chaos criterion can be used to investigate stability of classical solutions of field equations.

The Interplay of Maternal Sensitivity and Toddler Engagement of Mother in Predicting Self-Regulation

Science.gov (United States)

Ispa, Jean M.; Su-Russell, Chang; Palermo, Francisco; Carlo, Gustavo

2017-01-01

Using data from the Early Head Start Research and Evaluation Project, a cross-lag mediation model was tested to examine longitudinal relations among low-income mothers' sensitivity; toddlers' engagement of their mothers; and toddler's self-regulation at ages 1, 2, and 3 years (N = 2,958). Age 1 maternal sensitivity predicted self-regulation at…

Generalized melting criterion for beam-induced amorphization

International Nuclear Information System (INIS)

Lam, N. Q.; Okamoto, Paul R.

1993-09-01

Recent studies have shown that the mean-square static atomic displacements provide a generic measure of the enthalpy stored in the lattice in the form of chemical and topological disorder, and that the effect of the displacements on the softening of shear elastic constants is identical to that of heating. This finding lends support to a generalized form of the Lindemann phenomenological melting criterion and leads to a natural interpretion of crystalline-to-amorphous transformations as defect-induced melting of metastable crystals driven beyond a critical state of disorder where the melting temperature falls below the glass-transition temperature. Application of the generalized Lindemann criterion to both the crystalline and amorphous phases indicates that the enthalpies of the two phases become identical when their shear moduli become equal. This thermo-elastic rule provides a basis for predicting the relative susceptibility of compounds to amorphization in terms of their elastic properties as measured by Debye temperatures. The present approach can explain many of the basic findings on beam-induced amorphization of intermetallic compounds as well as amorphous phase formation associated with ion implantation, ion-beam mixing and other solid-state processes

The stressor criterion for posttraumatic stress disorder: Does it matter?

Science.gov (United States)

Roberts, Andrea L.; Dohrenwend, Bruce P.; Aiello, Allison; Wright, Rosalind J.; Maercker, Andreas; Galea, Sandro; Koenen, Karestan C.

2013-01-01

Objective The definition of the stressor criterion for posttraumatic stress disorder (“Criterion A1”) is hotly debated with major revisions being considered for DSM-V. We examine whether symptoms, course, and consequences of PTSD vary predictably with the type of stressful event that precipitates symptoms. Method We used data from the 2009 PTSD diagnostic subsample (N=3,013) of the Nurses Health Study II. We asked respondents about exposure to stressful events qualifying under 1) DSM-III, 2) DSM-IV, or 3) not qualifying under DSM Criterion A1. Respondents selected the event they considered worst and reported subsequent PTSD symptoms. Among participants who met all other DSM-IV PTSD criteria, we compared distress, symptom severity, duration, impairment, receipt of professional help, and nine physical, behavioral, and psychiatric sequelae (e.g. physical functioning, unemployment, depression) by precipitating event group. Various assessment tools were used to determine fulfillment of PTSD Criteria B through F and to assess these 14 outcomes. Results Participants with PTSD from DSM-III events reported on average 1 more symptom (DSM-III mean=11.8 symptoms, DSM-IV=10.7, non-DSM=10.9) and more often reported symptoms lasted one year or longer compared to participants with PTSD from other groups. However, sequelae of PTSD did not vary systematically with precipitating event type. Conclusions Results indicate the stressor criterion as defined by the DSM may not be informative in characterizing PTSD symptoms and sequelae. In the context of ongoing DSM-V revision, these results suggest that Criterion A1 could be expanded in DSM-V without much consequence for our understanding of PTSD phenomenology. Events not considered qualifying stressors under the DSM produced PTSD as consequential as PTSD following DSM-III events, suggesting PTSD may be an aberrantly severe but nonspecific stress response syndrome. PMID:22401487

PUBLICATION ACTIVITY AND ITS ROLE IN ASSESSMENT OF PROFESSIONAL ENGAGEMENT OF HEI ACADEMIC STAFF (RUSSIAN PRACTICES

Directory of Open Access Journals (Sweden)

I. B. Ardashkin

2016-01-01

Full Text Available The aim of the research is to analyze and summarize the Russian best practices of using the publication activity as a criterion to assess the professional activity of the academic staff; to identify the role of motivational factors as a method to manage and control the publication activity of the academic staff.Methods. The authors address the methodology of comprehensive research based on the method of document analysis, comparative analysis, and method of secondary use of sociological and psychological data.Results and scientific novelty concludes in presenting Russian and international best practices generalized on using the publication activity to assess the engagement of HEI (Higher Educational Institution academic staff; the most appropriate formats of using the publication activity as a criterion to assess the research component of the academic staff engagement are defined. Degree of reliability of this criterion is shown – its strengths and shortcomings. The conclusion is drawn on need of the essential changes in management of publication activity affecting both professional and motivational spheres of scientific and pedagogical staff. The most acceptable options of measurement of staff work efficiency of this category are formulated.Practical significance. The research outcomes can be the corpus for designing the assessment method for the professional engagement of the academic staff.

Attachment and personality predicts engagement in sexual harassment by male and female college students.

Science.gov (United States)

Mènard, Kim S; Shoss, Naomi E; Pincus, Aaron L

2010-01-01

The purpose of this study was to examine a trait model of personality (Five-Factor Model) as a mediator of the relationship between attachment styles and sexually harassing behavior in a sample of male (N = 148) and female (N = 278) college students. We found that gender (male) and low Agreeableness predicted engaging in sexual harassment and all three of its subtypes; gender harassment, unwanted sexual attention, and sexual coercion. Further, low Conscientiousness predicted overall sexual harassment, gender harassment, and unwanted sexual attention. Personality traits mediated the relationship between insecure attachment styles (Preoccupation with Relationships and Relationships as Secondary) and sexually harassing behaviors. Thus, factors beyond gender can help predict students' propensity to sexually harass others.

Job demands-resources predicting burnout and work engagement among Belgian home health care nurses: A cross-sectional study.

Science.gov (United States)

Vander Elst, Tinne; Cavents, Carolien; Daneels, Katrien; Johannik, Kristien; Baillien, Elfi; Van den Broeck, Anja; Godderis, Lode

A better knowledge of the job aspects that may predict home health care nurses' burnout and work engagement is important in view of stress prevention and health promotion. The Job Demands-Resources model predicts that job demands and resources relate to burnout and work engagement but has not previously been tested in the specific context of home health care nursing. The present study offers a comprehensive test of the Job-Demands Resources model in home health care nursing. We investigate the main and interaction effects of distinctive job demands (workload, emotional demands and aggression) and resources (autonomy, social support and learning opportunities) on burnout and work engagement. Analyses were conducted using cross-sectional data from 675 Belgian home health care nurses, who participated in a voluntary and anonymous survey. The results show that workload and emotional demands were positively associated with burnout, whereas aggression was unrelated to burnout. All job resources were associated with higher levels of work engagement and lower levels of burnout. In addition, social support buffered the positive relationship between workload and burnout. Home health care organizations should invest in dealing with workload and emotional demands and stimulating the job resources under study to reduce the risk of burnout and increase their nurses' work engagement. Copyright © 2016 Elsevier Inc. All rights reserved.

Ductile failure analysis of defective API X65 pipes based on stress-modified fracture strain criterion

International Nuclear Information System (INIS)

Oh, Chang Kyun; Kim, Yun Jae; Baek, Jong Hyun; Kim, Young Pyo; Kim, Woo Sik

2006-01-01

A local failure criterion for the API X65 steel is applied to predict ductile failure of full-scale API X65 pipes with simulated corrosion and gouge defects under internal pressure. The local failure criterion is the stress-modified fracture strain for the API X65 steel as a function of the stress triaxiality (defined by the ratio of the hydrostatic stress to the effective stress). Based on detailed FE analyses with the proposed local failure criteria, burst pressures of defective pipes are estimated and compared with experimental data. The predicted burst pressures are in good agreement with experimental data. Noting that an assessment equation against the gouge defect is not yet available, parametric study is performed, from which a simple equation is proposed to predict burst pressure for API X65 pipes with gouge defects

Wavelength selection in injection-driven Hele-Shaw flows: A maximum amplitude criterion

Science.gov (United States)

Dias, Eduardo; Miranda, Jose

2013-11-01

As in most interfacial flow problems, the standard theoretical procedure to establish wavelength selection in the viscous fingering instability is to maximize the linear growth rate. However, there are important discrepancies between previous theoretical predictions and existing experimental data. In this work we perform a linear stability analysis of the radial Hele-Shaw flow system that takes into account the combined action of viscous normal stresses and wetting effects. Most importantly, we introduce an alternative selection criterion for which the selected wavelength is determined by the maximum of the interfacial perturbation amplitude. The effectiveness of such a criterion is substantiated by the significantly improved agreement between theory and experiments. We thank CNPq (Brazilian Sponsor) for financial support.

The AP diameter of the pelvis: a new criterion for continence in the exstrophy complex?

International Nuclear Information System (INIS)

Ait-Ameur, A.; Kalifa, G.; Adamsbaum, C.; Wakim, A.; Dubousset, J.

2001-01-01

Reconstructive surgery of bladder exstrophy remains a challenge. By using CT of the pelvis, we suggest a new pre- and post-operative investigative procedure to define the AP diameter (APD) as a predictive criterion for continence in this anomaly. Patients and methods: Three axial CT slices were selected in nine children with exstrophy who had undergone neonatal reconstructive surgery. The three levels selected were the first sacral plate, the mid acetabular plane and the superior pubic spine. We used combined slices to measure: circle APD = distance between the first sacral vertebra and the pubic symphysis. circle Pubic diastasis (PD) circle Three angles defined on the transverse plane of the first sacral vertebra - iliac wing angle, sacropubic angle and acetabular version. In exstrophy, the angles demonstrate opening of the iliac wings and the pubic ramus, and acetabular retroversion compared to controls. Comparisons between controls, continent and incontinent patients reveal that in continent patients, APD increases with growth and seems to be a predictive criterion for continence, independent of diastasis of the pubic symphysis. We believe that CT of the pelvis with measurements of the APD should be performed in all neonates with bladder exstrophy before reconstructive surgery and for better understanding of the malformation. The APD seems to be predictive and may be a major criterion for continence, independent of PD. (orig.)

Suboptimal Criterion Learning in Static and Dynamic Environments.

Directory of Open Access Journals (Sweden)

Elyse H Norton

2017-01-01

Full Text Available Humans often make decisions based on uncertain sensory information. Signal detection theory (SDT describes detection and discrimination decisions as a comparison of stimulus "strength" to a fixed decision criterion. However, recent research suggests that current responses depend on the recent history of stimuli and previous responses, suggesting that the decision criterion is updated trial-by-trial. The mechanisms underpinning criterion setting remain unknown. Here, we examine how observers learn to set a decision criterion in an orientation-discrimination task under both static and dynamic conditions. To investigate mechanisms underlying trial-by-trial criterion placement, we introduce a novel task in which participants explicitly set the criterion, and compare it to a more traditional discrimination task, allowing us to model this explicit indication of criterion dynamics. In each task, stimuli were ellipses with principal orientations drawn from two categories: Gaussian distributions with different means and equal variance. In the covert-criterion task, observers categorized a displayed ellipse. In the overt-criterion task, observers adjusted the orientation of a line that served as the discrimination criterion for a subsequently presented ellipse. We compared performance to the ideal Bayesian learner and several suboptimal models that varied in both computational and memory demands. Under static and dynamic conditions, we found that, in both tasks, observers used suboptimal learning rules. In most conditions, a model in which the recent history of past samples determines a belief about category means fit the data best for most observers and on average. Our results reveal dynamic adjustment of discrimination criterion, even after prolonged training, and indicate how decision criteria are updated over time.

Harnessing Facebook for Smoking Reduction and Cessation Interventions: Facebook User Engagement and Social Support Predict Smoking Reduction

Science.gov (United States)

Marsch, Lisa A; Brunette, Mary F; Dallery, Jesse

2017-01-01

Background Social media technologies offer a novel opportunity for scalable health interventions that can facilitate user engagement and social support, which in turn may reinforce positive processes for behavior change. Objective By using principles from health communication and social support literature, we implemented a Facebook group–based intervention that targeted smoking reduction and cessation. This study hypothesized that participants’ engagement with and perceived social support from our Facebook group intervention would predict smoking reduction. Methods We recruited 16 regular smokers who live in the United States and who were motivated in quitting smoking at screening. We promoted message exposure as well as engagement and social support systems throughout the intervention. For message exposure, we posted prevalidated, antismoking messages (such as national antismoking campaigns) on our smoking reduction and cessation Facebook group. For engagement and social support systems, we delivered a high degree of engagement and social support systems during the second and third week of the intervention and a low degree of engagement and social support systems during the first and fourth week. A total of six surveys were conducted via Amazon Mechanical Turk (MTurk) at baseline on a weekly basis and at a 2-week follow-up. Results Of the total 16 participants, most were female (n=13, 81%), white (n=15, 94%), and between 25 and 50 years of age (mean 34.75, SD 8.15). There was no study attrition throughout the 6-time-point baseline, weekly, and follow-up surveys. We generated Facebook engagement and social support composite scores (mean 19.19, SD 24.35) by combining the number of likes each participant received and the number of comments or wall posts each participant posted on our smoking reduction and cessation Facebook group during the intervention period. The primary outcome was smoking reduction in the past 7 days measured at baseline and at the two

Development of a stress-induced martensitic transformation criterion for a Cu–Al–Be polycrystalline shape memory alloy undergoing uniaxial tension

International Nuclear Information System (INIS)

García-Castillo, F.N.; Cortés-Pérez, J.; Amigó, V.; Sánchez-Arévalo, F.M.; Lara-Rodríguez, G.A.

2015-01-01

This study presents a criterion for predicting the martensitic variants (MVs) that appear during the stress-induced martensitic transformation (SIMT) in a polycrystalline sample of Cu–11.5% wt. Al–0.5% wt. Be under simple tension. Our criterion is based on crystallographic parameters, such as the crystal orientation and Schmid factor (SF). The displacement vector fields (DVFs) were obtained in the observation system by a mathematical model and were used to distort the boundary of a set of grains. From the DVF, the strain tensor for each grain was obtained, and the strain ratio (SR) in the observation system was calculated. Electron backscattering diffraction (EBSD) measurements were performed to determine the crystal orientation of the grains. The inverse SF was used to determine the in-plane stress transformation diagrams (STDs) for each studied grain. The combination of a balance criterion (BC) and STD provided a criterion that allowed us to predict the possible order of stress-induced MVs formed as a function of the crystal orientation and thermomechanical parameters of the shape memory alloy (SMA) with higher accuracy than when using the criteria separately. To validate our criteria, we tested other researchers’ published results. Our results were in agreement and were capable of predicting the stress-induced MVs in a polycrystalline SMA

Criterion for vortex breakdown on shock wave and streamwise vortex interactions.

Science.gov (United States)

Hiejima, Toshihiko

2014-05-01

The interactions between supersonic streamwise vortices and oblique shock waves are theoretically and numerically investigated by three-dimensional (3D) Navier-Stokes equations. Based on the two inequalities, a criterion for shock-induced breakdown of the streamwise vortex is proposed. The simple breakdown condition depends on the Mach number, the swirl number, the velocity deficit, and the shock angle. According to the proposed criterion, the breakdown region expands as the Mach number increases. In numerical simulations, vortex breakdown appeared under conditions of multiple pressure increases and the helicity disappeared behind the oblique shock wave along the line of the vortex center. The numerical results are consistent with the predicted breakdown condition at Mach numbers 2.0 and 3.0. This study also found that the axial velocity deficit is important for classifying the breakdown configuration.

Predicting the onset of cracks in bulk metal forming by ductile damage criteria

DEFF Research Database (Denmark)

Christiansen, Peter; Nielsen, Chris Valentin; Martins, Paulo A.F.

2017-01-01

Three different ductile damage criteria, Ayada, normalized Cockcroft and Latham and a new shear stress based criterion taking into account hydrostatic tension, are utilized for predicting the onset of cracks in various deformation processes. It is found that the Ayada criterion predicts well...... the onset of cracks when they originate from hydrostatic tension. The shear based criterion predicts cracks triggered by shear and the normalized Cockcroft and Latham criterion indicates the overall area of onset of cracks caused by either hydrostatic or shear stresses. However the prediction...... is not as accurate as the Ayada criterion for cracks caused by hydrostatic tension....

Optimal design of constant-stress accelerated degradation tests using the M-optimality criterion

International Nuclear Information System (INIS)

Wang, Han; Zhao, Yu; Ma, Xiaobing; Wang, Hongyu

2017-01-01

In this paper, we propose the M-optimality criterion for designing constant-stress accelerated degradation tests (ADTs). The newly proposed criterion concentrates on the degradation mechanism equivalence rather than evaluation precision or prediction accuracy which is usually considered in traditional optimization criteria. Subject to the constraints of total sample number, test termination time as well as the stress region, an optimum constant-stress ADT plan is derived by determining the combination of stress levels and the number of samples allocated to each stress level, when the degradation path comes from inverse Gaussian (IG) process model with covariates and random effects. A numerical example is presented to verify the robustness of our proposed optimum plan and compare its efficiency with other test plans. Results show that, with a slightly relaxed requirement of evaluation precision and prediction accuracy, our proposed optimum plan reduces the dispersion of the estimated acceleration factor between the usage stress level and a higher accelerated stress level, which makes an important contribution to reliability demonstration and assessment tests. - Highlights: • We establish the necessary conditions for degradation mechanism equivalence of ADTs. • We propose the M-optimality criterion for designing constant-stress ADT plans. • The M-optimality plan reduces the dispersion of the estimated accelerated factors. • An electrical connector with its stress relaxation data is used for illustration.

Barriers to Mindfulness: a Path Analytic Model Exploring the Role of Rumination and Worry in Predicting Psychological and Physical Engagement in an Online Mindfulness-Based Intervention.

Science.gov (United States)

Banerjee, Moitree; Cavanagh, Kate; Strauss, Clara

2018-01-01

Little is known about the factors associated with engagement in mindfulness-based interventions (MBIs). Moreover, engagement in MBIs is usually defined in terms of class attendance ('physical engagement') only. However, in the psychotherapy literature, there is increasing emphasis on measuring participants' involvement with interventions ('psychological engagement'). This study tests a model that rumination and worry act as barriers to physical and psychological engagement in MBIs and that this in turn impedes learning mindfulness. One hundred and twenty-four participants were given access to a 2-week online mindfulness-based self-help (MBSH) intervention. Self-report measures of mindfulness, rumination, worry, positive beliefs about rumination, positive beliefs about worry and physical and psychological engagement were administered. A path analysis was used to test the linear relationships between the variables. Physical and psychological engagement were identified as two distinct constructs. Findings were that rumination and worry both predicted psychological disengagement in MBSH. Psychological engagement predicted change in the describe, act with awareness, non-judge and non-react facets of mindfulness while physical engagement only predicted changes in the non-react facet of mindfulness. Thus, rumination and worry may increase risk of psychological disengagement from MBSH which may in turn hinder cultivating mindfulness. Future suggestions for practice are discussed.

Harnessing Facebook for Smoking Reduction and Cessation Interventions: Facebook User Engagement and Social Support Predict Smoking Reduction.

Science.gov (United States)

Kim, Sunny Jung; Marsch, Lisa A; Brunette, Mary F; Dallery, Jesse

2017-05-23

Social media technologies offer a novel opportunity for scalable health interventions that can facilitate user engagement and social support, which in turn may reinforce positive processes for behavior change. By using principles from health communication and social support literature, we implemented a Facebook group-based intervention that targeted smoking reduction and cessation. This study hypothesized that participants' engagement with and perceived social support from our Facebook group intervention would predict smoking reduction. We recruited 16 regular smokers who live in the United States and who were motivated in quitting smoking at screening. We promoted message exposure as well as engagement and social support systems throughout the intervention. For message exposure, we posted prevalidated, antismoking messages (such as national antismoking campaigns) on our smoking reduction and cessation Facebook group. For engagement and social support systems, we delivered a high degree of engagement and social support systems during the second and third week of the intervention and a low degree of engagement and social support systems during the first and fourth week. A total of six surveys were conducted via Amazon Mechanical Turk (MTurk) at baseline on a weekly basis and at a 2-week follow-up. Of the total 16 participants, most were female (n=13, 81%), white (n=15, 94%), and between 25 and 50 years of age (mean 34.75, SD 8.15). There was no study attrition throughout the 6-time-point baseline, weekly, and follow-up surveys. We generated Facebook engagement and social support composite scores (mean 19.19, SD 24.35) by combining the number of likes each participant received and the number of comments or wall posts each participant posted on our smoking reduction and cessation Facebook group during the intervention period. The primary outcome was smoking reduction in the past 7 days measured at baseline and at the two-week follow-up. Compared with the baseline

A work criterion for plastic collapse

International Nuclear Information System (INIS)

Muscat, Martin; Mackenzie, Donald; Hamilton, Robert

2003-01-01

A new criterion for evaluating limit and plastic loads in pressure vessel design by analysis is presented. The proposed criterion is based on the plastic work dissipated in the structure as loading progresses and may be used for structures subject to a single load or a combination of multiple loads. Example analyses show that limit and plastic loads given by the plastic work criterion are robust and consistent. The limit and plastic loads are determined purely by the inelastic response of the structure and are not influenced by the initial elastic response: a problem with some established plastic criteria

Some properties of the computable cross-norm criterion for separability

International Nuclear Information System (INIS)

Rudolph, Oliver

2003-01-01

The computable cross-norm (CCN) criterion is a powerful analytical and computable separability criterion for bipartite quantum states, which is also known to systematically detect bound entanglement. In certain aspects this criterion complements the well-known Peres positive partial transpose (PPT) criterion. In the present paper we study important analytical properties of the CCN criterion. We show that in contrast to the PPT criterion it is not sufficient in dimension 2x2. In higher dimensions, theorems connecting the fidelity of a quantum state with the CCN criterion are proved. We also analyze the behavior of the CCN criterion under local operations and identify the operations that leave it invariant. It turns out that the CCN criterion is in general not invariant under local operations

Ethical leadership: meta-analytic evidence of criterion-related and incremental validity.

Science.gov (United States)

Ng, Thomas W H; Feldman, Daniel C

2015-05-01

This study examines the criterion-related and incremental validity of ethical leadership (EL) with meta-analytic data. Across 101 samples published over the last 15 years (N = 29,620), we observed that EL demonstrated acceptable criterion-related validity with variables that tap followers' job attitudes, job performance, and evaluations of their leaders. Further, followers' trust in the leader mediated the relationships of EL with job attitudes and performance. In terms of incremental validity, we found that EL significantly, albeit weakly in some cases, predicted task performance, citizenship behavior, and counterproductive work behavior-even after controlling for the effects of such variables as transformational leadership, use of contingent rewards, management by exception, interactional fairness, and destructive leadership. The article concludes with a discussion of ways to strengthen the incremental validity of EL. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Sequential lineups: shift in criterion or decision strategy?

Science.gov (United States)

Gronlund, Scott D

2004-04-01

R. C. L. Lindsay and G. L. Wells (1985) argued that a sequential lineup enhanced discriminability because it elicited use of an absolute decision strategy. E. B. Ebbesen and H. D. Flowe (2002) argued that a sequential lineup led witnesses to adopt a more conservative response criterion, thereby affecting bias, not discriminability. Height was encoded as absolute (e.g., 6 ft [1.83 m] tall) or relative (e.g., taller than). If a sequential lineup elicited an absolute decision strategy, the principle of transfer-appropriate processing predicted that performance should be best when height was encoded absolutely. Conversely, if a simultaneous lineup elicited a relative decision strategy, performance should be best when height was encoded relatively. The predicted interaction was observed, providing direct evidence for the decision strategies explanation of what happens when witnesses view a sequential lineup.

Satisfying the Einstein–Podolsky–Rosen criterion with massive particles

Science.gov (United States)

Peise, J.; Kruse, I.; Lange, K.; Lücke, B.; Pezzè, L.; Arlt, J.; Ertmer, W.; Hammerer, K.; Santos, L.; Smerzi, A.; Klempt, C.

2015-01-01

In 1935, Einstein, Podolsky and Rosen (EPR) questioned the completeness of quantum mechanics by devising a quantum state of two massive particles with maximally correlated space and momentum coordinates. The EPR criterion qualifies such continuous-variable entangled states, where a measurement of one subsystem seemingly allows for a prediction of the second subsystem beyond the Heisenberg uncertainty relation. Up to now, continuous-variable EPR correlations have only been created with photons, while the demonstration of such strongly correlated states with massive particles is still outstanding. Here we report on the creation of an EPR-correlated two-mode squeezed state in an ultracold atomic ensemble. The state shows an EPR entanglement parameter of 0.18(3), which is 2.4 s.d. below the threshold 1/4 of the EPR criterion. We also present a full tomographic reconstruction of the underlying many-particle quantum state. The state presents a resource for tests of quantum nonlocality and a wide variety of applications in the field of continuous-variable quantum information and metrology. PMID:26612105

Satisfying the Einstein-Podolsky-Rosen criterion with massive particles.

Science.gov (United States)

Peise, J; Kruse, I; Lange, K; Lücke, B; Pezzè, L; Arlt, J; Ertmer, W; Hammerer, K; Santos, L; Smerzi, A; Klempt, C

2015-11-27

In 1935, Einstein, Podolsky and Rosen (EPR) questioned the completeness of quantum mechanics by devising a quantum state of two massive particles with maximally correlated space and momentum coordinates. The EPR criterion qualifies such continuous-variable entangled states, where a measurement of one subsystem seemingly allows for a prediction of the second subsystem beyond the Heisenberg uncertainty relation. Up to now, continuous-variable EPR correlations have only been created with photons, while the demonstration of such strongly correlated states with massive particles is still outstanding. Here we report on the creation of an EPR-correlated two-mode squeezed state in an ultracold atomic ensemble. The state shows an EPR entanglement parameter of 0.18(3), which is 2.4 s.d. below the threshold 1/4 of the EPR criterion. We also present a full tomographic reconstruction of the underlying many-particle quantum state. The state presents a resource for tests of quantum nonlocality and a wide variety of applications in the field of continuous-variable quantum information and metrology.

The qualitative criterion of transient angle stability

DEFF Research Database (Denmark)

Lyu, R.; Xue, Y.; Xue, F.

2015-01-01

In almost all the literatures, the qualitative assessment of transient angle stability extracts the angle information of generators based on the swing curve. As the angle (or angle difference) of concern and the threshold value rely strongly on the engineering experience, the validity and robust...... of these criterions are weak. Based on the stability mechanism from the extended equal area criterion (EEAC) theory and combining with abundant simulations of real system, this paper analyzes the criterions in most literatures and finds that the results could be too conservative or too optimistic. It is concluded...

Failure Criterion for Brick Masonry: A Micro-Mechanics Approach

Directory of Open Access Journals (Sweden)

Kawa Marek

2015-02-01

Full Text Available The paper deals with the formulation of failure criterion for an in-plane loaded masonry. Using micro-mechanics approach the strength estimation for masonry microstructure with constituents obeying the Drucker-Prager criterion is determined numerically. The procedure invokes lower bound analysis: for assumed stress fields constructed within masonry periodic cell critical load is obtained as a solution of constrained optimization problem. The analysis is carried out for many different loading conditions at different orientations of bed joints. The performance of the approach is verified against solutions obtained for corresponding layered and block microstructures, which provides the upper and lower strength bounds for masonry microstructure, respectively. Subsequently, a phenomenological anisotropic strength criterion for masonry microstructure is proposed. The criterion has a form of conjunction of Jaeger critical plane condition and Tsai-Wu criterion. The model proposed is identified based on the fitting of numerical results obtained from the microstructural analysis. Identified criterion is then verified against results obtained for different loading orientations. It appears that strength of masonry microstructure can be satisfactorily described by the criterion proposed.

Proposal of failure criterion applicable to finite element analysis results for wall-thinned pipes under bending load

Energy Technology Data Exchange (ETDEWEB)

Meshii, Toshiyuki, E-mail: meshii@u-fukui.ac.jp [Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui (Japan); Ito, Yoshiaki [Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui (Japan)

2012-01-15

Highlights: Black-Right-Pointing-Pointer Limit bending load (LBL) of wall-thinned pipe by large strain FEA was considered. Black-Right-Pointing-Pointer Net section yield load had sufficient margin to LBL. Black-Right-Pointing-Pointer LBL for collapse was the load when volume with nominal thickness yielded. Black-Right-Pointing-Pointer LBL for cracking was the load when flawed section stress exceeded tensile strength. Black-Right-Pointing-Pointer Failure criterion considering above was named Domain Collapse Criterion. - Abstract: In this work, a failure criterion applicable to large strain Finite Element Analysis (FEA) results was proposed in order to predict both the fracture mode (collapse or cracking) and the limit bending load of wall-thinned straight pipes. This work was motivated from the recent experimental results of ; that is, fracture mode is not always collapse, and the fracture mode affects the limit bending load. The key finding in comparing their test results and a detailed large strain FEA results was that the Mises stress distribution at the limit bending load of a flawed cylinder was similar to that of a flawless cylinder; specifically, in case of collapse, the Mises stress exceeded the true yield stress of a material for the whole 'volume' of a cylinder with a nominal wall thickness. Based on this finding, a failure criterion applicable to large strain FEA results of wall-thinned straight pipes under a bending load that can predict both fracture mode and limit bending load was proposed and was named the Domain Collapse Criterion (DCC). DCC predicts the limit bending load as the lower value of either the M{sub c}{sup FEA}, which is the load at which the Mises stress exceeds the true yield strength of a straight pipe for the whole 'volume' with a nominal wall thickness (fracture mode: collapse), or the M{sub c}{sup FEAb}, which is the load at which the Mises stress in a section of the flaw ligament exceeds the true tensile stress

A Failure Criterion for Concrete

DEFF Research Database (Denmark)

Ottosen, N. S.

1977-01-01

A four-parameter failure criterion containing all the three stress invariants explicitly is proposed for short-time loading of concrete. It corresponds to a smooth convex failure surface with curved meridians, which open in the negative direction of the hydrostatic axis, and the trace in the devi......A four-parameter failure criterion containing all the three stress invariants explicitly is proposed for short-time loading of concrete. It corresponds to a smooth convex failure surface with curved meridians, which open in the negative direction of the hydrostatic axis, and the trace...

The EMU debt criterion: an interpretation

Directory of Open Access Journals (Sweden)

R. BERNDSEN

1997-12-01

Full Text Available The convergence criteria specified in the Maastricht Treaty on government deficit and debt, inflation, the exchange rate and the long-term interest rate will play an important, if not decisive, role in determining which countries move on to the third stage of the Economic and Monetary Union (EMU. The aim of this work is to provide a possible interpretation of the EMU debt criterion. The author investigates the government debt criterion which, as Article 104c(2b of the Treaty shows, has a considerable scope for interpretation. Although this subject has been discussed extensively, relatively little work has been done to develop a clear interpretation of the EMU debt criterion. A flexible approach is adopted in which parts of the relevant Treaty text are characterised using two parameters.

Inviscid criterion for decomposing scales

Science.gov (United States)

Zhao, Dongxiao; Aluie, Hussein

2018-05-01

The proper scale decomposition in flows with significant density variations is not as straightforward as in incompressible flows, with many possible ways to define a "length scale." A choice can be made according to the so-called inviscid criterion [Aluie, Physica D 24, 54 (2013), 10.1016/j.physd.2012.12.009]. It is a kinematic requirement that a scale decomposition yield negligible viscous effects at large enough length scales. It has been proved [Aluie, Physica D 24, 54 (2013), 10.1016/j.physd.2012.12.009] recently that a Favre decomposition satisfies the inviscid criterion, which is necessary to unravel inertial-range dynamics and the cascade. Here we present numerical demonstrations of those results. We also show that two other commonly used decompositions can violate the inviscid criterion and, therefore, are not suitable to study inertial-range dynamics in variable-density and compressible turbulence. Our results have practical modeling implication in showing that viscous terms in Large Eddy Simulations do not need to be modeled and can be neglected.

Accuracy of a selection criterion for glass forming ability in the Ni–Nb–Zr system

International Nuclear Information System (INIS)

Déo, L.P.; Oliveira, M.F. de

2014-01-01

Highlights: • We applied a selection in the Ni–Nb–Zr system to find alloys with high GFA. • We used the thermal parameter γ m to evaluate the GFA of alloys. • The correlation between the γ m parameter and R c in the studied system is poor. • The effect of oxygen impurity reduced dramatically the GFA of alloys. • Unknown intermetallic compounds reduced the accuracy of the criterion. - Abstract: Several theories have been developed and applied in metallic systems in order to find the best stoichiometries with high glass forming ability; however there is no universal theory to predict the glass forming ability in metallic systems. Recently a selection criterion was applied in the Zr–Ni–Cu system and it was found some correlation between experimental and theoretical data. This criterion correlates critical cooling rate for glass formation with topological instability of stable crystalline structures; average work function difference and average electron density difference among the constituent elements of the alloy. In the present work, this criterion was applied in the Ni–Nb–Zr system. It was investigated the influence of factors not considered in the calculation and on the accuracy of the criterion, such as unknown intermetallic compounds and oxygen contamination. Bulk amorphous specimens were produced by injection casting. The amorphous nature was analyzed by X-ray diffraction and differential scanning calorimetry; oxygen contamination was quantified by the inert gas fusion method

Plasma sheath criterion in thermal electronegative plasmas

International Nuclear Information System (INIS)

Ghomi, Hamid; Khoramabadi, Mansour; Ghorannevis, Mahmod; Shukla, Padma Kant

2010-01-01

The sheath formation criterion in electronegative plasma is examined. By using a multifluid model, it is shown that in a collisional sheath there will be upper as well as lower limits for the sheath velocity criterion. However, the parameters of the negative ions only affect the lower limit.

Emotional engagements predict and enhance social cognition in young chimpanzees.

Science.gov (United States)

Bard, Kim A; Bakeman, Roger; Boysen, Sarah T; Leavens, David A

2014-09-01

Social cognition in infancy is evident in coordinated triadic engagements, that is, infants attending jointly with social partners and objects. Current evolutionary theories of primate social cognition tend to highlight species differences in cognition based on human-unique cooperative motives. We consider a developmental model in which engagement experiences produce differential outcomes. We conducted a 10-year-long study in which two groups of laboratory-raised chimpanzee infants were given quantifiably different engagement experiences. Joint attention, cooperativeness, affect, and different levels of cognition were measured in 5- to 12-month-old chimpanzees, and compared to outcomes derived from a normative human database. We found that joint attention skills significantly improved across development for all infants, but by 12 months, the humans significantly surpassed the chimpanzees. We found that cooperativeness was stable in the humans, but by 12 months, the chimpanzee group given enriched engagement experiences significantly surpassed the humans. Past engagement experiences and concurrent affect were significant unique predictors of both joint attention and cooperativeness in 5- to 12-month-old chimpanzees. When engagement experiences and concurrent affect were statistically controlled, joint attention and cooperation were not associated. We explain differential social cognition outcomes in terms of the significant influences of previous engagement experiences and affect, in addition to cognition. Our study highlights developmental processes that underpin the emergence of social cognition in support of evolutionary continuity. © 2014 The Authors. Developmental Science Published by John Wiley & Sons Ltd.

A pellet-clad interaction failure criterion

International Nuclear Information System (INIS)

Howl, D.A.; Coucill, D.N.; Marechal, A.J.C.

1983-01-01

A Pellet-Clad Interaction (PCI) failure criterion, enabling the number of fuel rod failures in a reactor core to be determined for a variety of normal and fault conditions, is required for safety analysis. The criterion currently being used for the safety analysis of the Pressurized Water Reactor planned for Sizewell in the UK is defined and justified in this paper. The criterion is based upon a threshold clad stress which diminishes with increasing fast neutron dose. This concept is consistent with the mechanism of clad failure being stress corrosion cracking (SCC); providing excess corrodant is always present, the dominant parameter determining the propagation of SCC defects is stress. In applying the criterion, the SLEUTH-SEER 77 fuel performance computer code is used to calculate the peak clad stress, allowing for concentrations due to pellet hourglassing and the effect of radial cracks in the fuel. The method has been validated by analysis of PCI failures in various in-reactor experiments, particularly in the well-characterised power ramp tests in the Steam Generating Heavy Water Reactor (SGHWR) at Winfrith. It is also in accord with out-of-reactor tests with iodine and irradiated Zircaloy clad, such as those carried out at Kjeller in Norway. (author)

A multipole acceptability criterion for electronic structure theory

International Nuclear Information System (INIS)

Schwegler, E.; Challacombe, M.; Head-Gordon, M.

1998-01-01

Accurate and computationally inexpensive estimates of multipole expansion errors are crucial to the success of several fast electronic structure methods. In this paper, a new nonempirical multipole acceptability criterion is described that is directly applicable to expansions of high order moments. Several model calculations typical of electronic structure theory are presented to demonstrate its performance. For cases involving small translation distances, accuracies are increased by up to five orders of magnitude over an empirical criterion. The new multipole acceptance criterion is on average within an order of magnitude of the exact expansion error. Use of the multipole acceptance criterion in hierarchical multipole based methods as well as in traditional electronic structure methods is discussed. copyright 1998 American Institute of Physics

Effective Social Media Engagement for Nonprofits: What Matters?

Directory of Open Access Journals (Sweden)

Julia L Carboni

2015-03-01

Full Text Available We employ public management relationship theory to examine how nonprofits can effectively engage social media stakeholders in two-way communication. Though many nonprofit organizations have a social media presence, there is variance in how well organizations use social media to engage stakeholders. Simply having a social media presence is not enough to engage stakeholders.  We examine Facebook posts of a stratified random sample of youth development organizations to determine what predicts stakeholder engagement. We find the type of Facebook post is a significant predictor of stakeholder engagement.  Longer posts also significantly predict increased stakeholder engagement.  At the organizational level, having many posts is a significant negative predictor of stakeholder engagement, indicating that users may feel bombarded and are less likely to engage.  Increased organizational spending on advertising as a proportion of total budget is positively associated with stakeholder engagement. 

Adults' future time perspective predicts engagement in physical activity.

Science.gov (United States)

Stahl, Sarah T; Patrick, Julie Hicks

2012-07-01

Our aim was to examine how the relations among known predictors of physical activity, such as age, sex, and body mass index, interact with future time perspective (FTP) and perceived functional limitation to explain adults' engagement in physical activity. Self-report data from 226 adults (range 20-88 years) were collected to examine the hypothesis that a more expansive FTP is associated with engagement in physical activity. Results indicated a good fit of the data to the model χ(2) (4, N = 226) = 7.457, p = .14 and accounted for a moderate amount of variance in adults' physical activity (R(2) = 15.7). Specifically, results indicated that perceived functional limitation (β = -.140) and FTP (β = .162) were directly associated with physical activity. Age was indirectly associated with physical activity through its association with perceived functional limitation (β = -.264) and FTP (β = .541). Results indicate that FTP may play an important role in explaining engagement in health promoting behaviors across the life span. Researchers should consider additional constructs and perhaps adopt socioemotional selectivity theory when explaining adults' engagement in physical activity.

Goldberger-Treiman constraint criterion for hyperon coupling constants

International Nuclear Information System (INIS)

General, Ignacio J.; Cotanch, Stephen R.

2004-01-01

The generalized Goldberger-Treiman relation is combined with the Dashen-Weinstein sum rule to provide a constraint equation between the g KΣN and g KΛN coupling constants. A comprehensive examination of the published phenomenological and theoretical hyperon couplings has yielded a much smaller set of values, spanning the intervals 0.80≤g KΣN /√(4π)≤2.72 and -3.90≤g KΛN /√(4π)≤-1.84, consistent with this criterion. The broken SU F (3) and Goldberger-Treiman hyperon couplings satisfy the constraint along with predictions from a Taylor series extrapolation using the same momentum variation as exhibited by g πNN

Unified Bohm criterion

Energy Technology Data Exchange (ETDEWEB)

Kos, L. [LECAD Laboratory, Faculty of Mechanical Engineering, University of Ljubljana, SI-1000 Ljubljana (Slovenia); Tskhakaya, D. D.; Jelić, N. [Institute for Theoretical Physics, Fusion@ÖAW, University of Innsbruck, A-6020 Innsbruck (Austria)

2015-09-15

Recent decades have seen research into the conditions necessary for the formation of the monotonic potential shape in the sheath, appearing at the plasma boundaries like walls, in fluid, and kinetic approximations separately. Although either of these approaches yields a formulation commonly known as the much-acclaimed Bohm criterion (BC), the respective results involve essentially different physical quantities that describe the ion gas behavior. In the fluid approach, such a quantity is clearly identified as the ion directional velocity. In the kinetic approach, the ion behavior is formulated via a quantity (the squared inverse velocity averaged by the ion distribution function) without any clear physical significance, which is, moreover, impractical. In the present paper, we try to explain this difference by deriving a condition called here the Unified Bohm Criterion, which combines an advanced fluid model with an upgraded explicit kinetic formula in a new form of the BC. By introducing a generalized polytropic coefficient function, the unified BC can be interpreted in a form that holds, irrespective of whether the ions are described kinetically or in the fluid approximation.

Reactor instrumentation. Definition of the single failure criterion

International Nuclear Information System (INIS)

1980-12-01

The standard defines the single failure criterion which is used in other IEC publications on reactor safety systems. The purpose of the single failure criterion is the assurance of minimum redundancy. (orig./HP) [de

Criterion of cleavage crack propagation and arrest in a nuclear PWR vessel steel

International Nuclear Information System (INIS)

Bousquet, Amaury

2013-01-01

The purpose of this PhD thesis is to understand physical mechanisms of cleavage crack propagation and arrest in the 16MND5 PWR vessel steel and to propose a robust predicting model based on a brittle fracture experimental campaign of finely instrumented laboratory specimens associated with numerical computations. First, experiments were carried out on thin CT25 specimens at five temperatures (-150 C, -125 C, -100 C, -7 C, -50 C). Two kinds of crack path, straight or branching path, have been observed. To characterize crack propagation and to measure crack speed, a high-speed framing camera system was used, combined with the development of an experimental protocol which allowed to observe CT surface without icing inside the thermal chamber and on the specimen. The framing camera (520 000 fps) has allowed to have a very accurate estimation of crack speed on the complete ligament of CT (∼ 25 mm). Besides, to analyse experiments and to study the impact of viscosity on the mechanical response around the crack tip, the elastic-viscoplastic behavior of the ferritic steel has been studied up to a strain rate of 104 s -1 for the tested temperatures.The extended Finite Element Method (X-FEM) was used in CAST3M FE software to model crack propagation. Numerical computations combine a local non linear dynamic approach with a RKR type fracture stress criterion to a characteristic distance. The work carried out has confirmed the form of the criterion proposed by Prabel at -125 C, and has identified the dependencies of the criterion on temperature and strain rate. From numerical analyzes in 2D and 3D, a multi-temperature fracture stress criterion, increasing function of the strain rate, was proposed. Predictive modeling were used to confirm the identified criterion on two specimen geometries (CT and compressive ring) in mode I at different temperatures. SEM observations and 3D analyzes made with optical microscope showed that the fracture mechanism was the cleavage associated

Modified Schur-Cohn Criterion for Stability of Delayed Systems

Directory of Open Access Journals (Sweden)

Juan Ignacio Mulero-Martínez

2015-01-01

Full Text Available A modified Schur-Cohn criterion for time-delay linear time-invariant systems is derived. The classical Schur-Cohn criterion has two main drawbacks; namely, (i the dimension of the Schur-Cohn matrix generates some round-off errors eventually resulting in a polynomial of s with erroneous coefficients and (ii imaginary roots are very hard to detect when numerical errors creep in. In contrast to the classical Schur-Cohn criterion an alternative approach is proposed in this paper which is based on the application of triangular matrices over a polynomial ring in a similar way as in the Jury test of stability for discrete systems. The advantages of the proposed approach are that it halves the dimension of the polynomial and it only requires seeking real roots, making this modified criterion comparable to the Rekasius substitution criterion.

Psychosocial assessments for young people: a systematic review examining acceptability, disclosure and engagement, and predictive utility

Directory of Open Access Journals (Sweden)

Bradford S

2012-12-01

Full Text Available Sally Bradford,1 Debra Rickwood1,21Faculty of Health, University of Canberra, Canberra, 2Headspace National Youth Mental Health Foundation, North Melbourne, AustraliaAbstract: Adolescence and young adulthood are often turbulent periods in a person’s life. There are high rates of accidental deaths, suicide, mental health concerns, substance use, and sexual experimentation. Health care professionals need to conduct holistic assessments of clients in these developmental life stages to identify psychosocial risks and provide targeted early intervention and implement prevention strategies. The most useful psychosocial assessments for most health care professionals are those that can provide a complete picture of the young person’s life and circumstances. This article identifies psychosocial assessment instruments that can be used as an initial assessment and engagement tool with the general population of young people presenting for health care. We review the psychometric properties of each of the instruments, determining what type of instrument is most acceptable to young people, whether any can increase disclosure and improve engagement between young people and health professionals, and whether they have predictive utility. The search strategy complied with the relevant sections of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA statement. A total of 89 published articles were identified, covering 31 different assessment instruments. Results indicated that those that were self-administered were most acceptable to young people, although it is unclear whether pen-and-paper or computer formats were preferred. Most psychosocial assessments can improve rates of disclosure and enhance engagement between young people and health professionals; however, worryingly, we found evidence that clinicians did not always respond to some of the most serious identified risks. Only for one instrument was there any mention of

Future Time Orientation Predicts Academic Engagement among First-Year University Students

Science.gov (United States)

Horstmanshof, Louise; Zimitat, Craig

2007-01-01

Background: Enhancing student engagement is considered an important strategy for improving retention. Students' Time Perspective is an under-researched factor that may significantly influence student engagement. Aims: This study examines interrelationships between elements of student engagement and relationship with Time Perspective. We propose…

FFTBM and primary pressure acceptance criterion

International Nuclear Information System (INIS)

Prosek, A.

2004-01-01

When thermalhydraulic computer codes are used for simulation in the area of nuclear engineering the question is how to conduct an objective comparison between the code calculation and measured data. To answer this the fast Fourier transform based method (FFTBM) was developed. When the FFTBM method was developed the acceptance criteria for primary pressure and total accuracy were set. In the recent study the FFTBM method was used for accuracy quantification of RD-14M large LOCA test B9401 calculations. The blind accuracy analysis indicated good total accuracy while the primary pressure criterion was not fulfilled. The objective of the study was therefore to investigate the reasons for not fulfilling the primary pressure acceptance criterion and the applicability of the criterion to experimental facilities simulating heavy water reactor. The results of the open quantitative analysis showed that sensitivity analysis for influence parameters provide sufficient information to judge in which calculation the accuracy of primary pressure is acceptable. (author)

A ductile fracture criterion with Zener-Hollomon parameter of pure molybdenum sheet in thermal forming

Directory of Open Access Journals (Sweden)

Wang Chu

2015-01-01

Full Text Available Formability of pure molybdenum in thermal forming process has been greatly improved, but it is still hard to avoid the generation of rupture and other quality defects. In this paper, a ductile fracture criterion of pure molybdenum sheet in thermal forming was established by considering the plastic deformation capacity of material and stress states, which can be used to describe fracture behaviour and critical rupture prediction of pure molybdenum sheet during hot forming process. Based on the isothermal uniaxial tensile tests which performed at 993 to 1143 K with strain rate range from 0.0005 to 0.2 s−1, the material parameters are calculated by the combination method of experiment with FEsimulation. Based on the observation, new fracture criteria can be expressed as a function of Zener-Hollomon parameter. The critical fracture value that calculated by Oyane-Sato criterion increases with increasing temperature and decreasing strain rate. The ductile fracture criterion with Zener-Hollomon parameter of pure molybdenum in thermal forming is proposed.

Does the Lowest Bid Price Evaluation Criterion Make for a More Efficient Public Procurement Selection Criterion? (Case of the Czech Republic

Directory of Open Access Journals (Sweden)

Ochrana František

2015-06-01

Full Text Available Through the institute of public procurement a considerable volume of financial resources is allocated. It is therefore in the interest of contracting entities to seek ways of how to achieve an efficient allocation of resources. Some public contract-awarding entities, along with some public-administration authorities in the Czech Republic, believe that the use of a single evaluation criterion (the lowest bid price results in a more efficient tender for a public contract. It was found that contracting entities in the Czech Republic strongly prefer to use the lowest bid price criterion. Within the examined sample, 86.5 % of public procurements were evaluated this way. The analysis of the examined sample of public contracts proved that the choice of an evaluation criterion, even the preference of the lowest bid price criterion, does not have any obvious impact on the final cost of a public contract. The study concludes that it is inappropriate to prefer the criterion of the lowest bid price within the evaluation of public contracts that are characterised by their complexity (including public contracts for construction works and public service contracts. The findings of the Supreme Audit Office related to the inspection of public contracts indicate that when using the lowest bid price as an evaluation criterion, a public contract may indeed be tendered with the lowest bid price, but not necessarily the best offer in terms of supplied quality. It is therefore not appropriate to use the lowest bid price evaluation criterion to such an extent for the purpose of evaluating work and services. Any improvement to this situation requires a corresponding amendment to the Law on Public Contracts and mainly a radical change in the attitude of the Office for the Protection of Competition towards proposed changes, as indicated within the conclusions and recommendations proposed by this study.

Application of a new criterion for assessing the susceptibility to internal erosion

Energy Technology Data Exchange (ETDEWEB)

Li, M.; Garner, S.J. [BC Hydro, Burnaby, BC (Canada); Fannin, R.J. [British Columbia Univ., Vancouver, BC (Canada)

2009-07-01

Occasionally, internal erosion can occur in internally unstable soils that are subject to seepage flow. This paper presented a modification to the Kenney-Lau criterion for assessing susceptibility to internal erosion in widely-graded cohesionless soils. The original Kenney-Lau criterion and the newly-proposed Li-Fannin criteria were both used to evaluate the grading stability of filter and core materials from two zoned earthfill dams in British Columbia. Using a statistical approach, the criteria were applied to construction data to account for the many gradation curves available within the specification envelope for materials used in construction. The paper discussed the implications of the findings within the context of laboratory permeameter tests on the same soils, and also based on a sinkhole incident at one of the dams. It was concluded that the Kenney-Lau method appears to be less conservative for predicting the internal instability of widely graded materials. 16 refs., 5 figs.

Protection motivation theory in predicting intention to engage in protective behaviors against schistosomiasis among middle school students in rural China.

Science.gov (United States)

Xiao, Han; Li, Shiyue; Chen, Xinguang; Yu, Bin; Gao, Mengting; Yan, Hong; Okafor, Chukwuemeka N

2014-10-01

Among millions of people who suffer from schistosomiasis in China, adolescents are at increased risk to be infected. However, there is a lack of theory-guided behavioral prevention intervention programs to protect these adolescents. This study attempted to apply the Protection Motivation Theory (PMT) in predicting intentions to engage in protective behaviors against schistosomiasis infection. The participants were selected using the stratified cluster sampling method. Survey data were collected using anonymous self-reported questionnaire. The advanced structural equation modeling (SEM) method was utilized to assess the complex relationship among schistosomiasis knowledge, previous risk exposure and protective measures in predicting intentions to engage in protective behavior through the PMT constructs. Approximately 70% of participants reported they were always aware of schistosomiasis before exposure to water with endemic schistosomiasis, 6% of the participants reported frequency of weekly or monthly prior exposure to snail-conditioned water. 74% of participants reported having always engaged in protective behaviors in the past three months. Approximately 7% were unlikely or very unlikely to avoid contact with snail-conditioned water, and to use protective behaviors before exposure. Results from SEM analysis indicated that both schistosomiasis knowledge and prior exposure to schistosomiasis were indirectly related to behavior intentions through intrinsic rewards and self-efficacy; prior protective behaviors were indirectly related to behavior intentions through severity, intrinsic rewards and self-efficacy, while awareness had an indirect relationship with behavior intentions through self-efficacy. Among the seven PMT constructs, severity, intrinsic rewards and self-efficacy were significantly associated with behavior intentions. The PMT can be used to predict the intention to engage in protective behaviors against schistosomiasis. Schistosomiasis intervention

Protection Motivation Theory in Predicting Intention to Engage in Protective Behaviors against Schistosomiasis among Middle School Students in Rural China

Science.gov (United States)

Chen, Xinguang; Yu, Bin; Gao, Mengting; Yan, Hong; Okafor, Chukwuemeka N.

2014-01-01

Background Among millions of people who suffer from schistosomiasis in China, adolescents are at increased risk to be infected. However, there is a lack of theory-guided behavioral prevention intervention programs to protect these adolescents. This study attempted to apply the Protection Motivation Theory (PMT) in predicting intentions to engage in protective behaviors against schistosomiasis infection. Methods The participants were selected using the stratified cluster sampling method. Survey data were collected using anonymous self-reported questionnaire. The advanced structural equation modeling (SEM) method was utilized to assess the complex relationship among schistosomiasis knowledge, previous risk exposure and protective measures in predicting intentions to engage in protective behavior through the PMT constructs. Principal Findings Approximately 70% of participants reported they were always aware of schistosomiasis before exposure to water with endemic schistosomiasis, 6% of the participants reported frequency of weekly or monthly prior exposure to snail-conditioned water. 74% of participants reported having always engaged in protective behaviors in the past three months. Approximately 7% were unlikely or very unlikely to avoid contact with snail-conditioned water, and to use protective behaviors before exposure. Results from SEM analysis indicated that both schistosomiasis knowledge and prior exposure to schistosomiasis were indirectly related to behavior intentions through intrinsic rewards and self-efficacy; prior protective behaviors were indirectly related to behavior intentions through severity, intrinsic rewards and self-efficacy, while awareness had an indirect relationship with behavior intentions through self-efficacy. Among the seven PMT constructs, severity, intrinsic rewards and self-efficacy were significantly associated with behavior intentions. Conclusions The PMT can be used to predict the intention to engage in protective behaviors against

Protection motivation theory in predicting intention to engage in protective behaviors against schistosomiasis among middle school students in rural China.

Directory of Open Access Journals (Sweden)

Han Xiao

2014-10-01

Full Text Available Among millions of people who suffer from schistosomiasis in China, adolescents are at increased risk to be infected. However, there is a lack of theory-guided behavioral prevention intervention programs to protect these adolescents. This study attempted to apply the Protection Motivation Theory (PMT in predicting intentions to engage in protective behaviors against schistosomiasis infection.The participants were selected using the stratified cluster sampling method. Survey data were collected using anonymous self-reported questionnaire. The advanced structural equation modeling (SEM method was utilized to assess the complex relationship among schistosomiasis knowledge, previous risk exposure and protective measures in predicting intentions to engage in protective behavior through the PMT constructs.Approximately 70% of participants reported they were always aware of schistosomiasis before exposure to water with endemic schistosomiasis, 6% of the participants reported frequency of weekly or monthly prior exposure to snail-conditioned water. 74% of participants reported having always engaged in protective behaviors in the past three months. Approximately 7% were unlikely or very unlikely to avoid contact with snail-conditioned water, and to use protective behaviors before exposure. Results from SEM analysis indicated that both schistosomiasis knowledge and prior exposure to schistosomiasis were indirectly related to behavior intentions through intrinsic rewards and self-efficacy; prior protective behaviors were indirectly related to behavior intentions through severity, intrinsic rewards and self-efficacy, while awareness had an indirect relationship with behavior intentions through self-efficacy. Among the seven PMT constructs, severity, intrinsic rewards and self-efficacy were significantly associated with behavior intentions.The PMT can be used to predict the intention to engage in protective behaviors against schistosomiasis. Schistosomiasis

Covariance-Based Measurement Selection Criterion for Gaussian-Based Algorithms

Directory of Open Access Journals (Sweden)

Fernando A. Auat Cheein

2013-01-01

Full Text Available Process modeling by means of Gaussian-based algorithms often suffers from redundant information which usually increases the estimation computational complexity without significantly improving the estimation performance. In this article, a non-arbitrary measurement selection criterion for Gaussian-based algorithms is proposed. The measurement selection criterion is based on the determination of the most significant measurement from both an estimation convergence perspective and the covariance matrix associated with the measurement. The selection criterion is independent from the nature of the measured variable. This criterion is used in conjunction with three Gaussian-based algorithms: the EIF (Extended Information Filter, the EKF (Extended Kalman Filter and the UKF (Unscented Kalman Filter. Nevertheless, the measurement selection criterion shown herein can also be applied to other Gaussian-based algorithms. Although this work is focused on environment modeling, the results shown herein can be applied to other Gaussian-based algorithm implementations. Mathematical descriptions and implementation results that validate the proposal are also included in this work.

Angular criterion for distinguishing between Fraunhofer and Fresnel diffraction

International Nuclear Information System (INIS)

Medina, Francisco F.; Garcia-Sucerquia, Jorge; Castaneda, Roman; Matteucci, Giorgio

2003-03-01

The distinction between Fresnel and Fraunhofer diffraction is a crucial condition for the accurate analysis of diffracting structures. In this paper we propose a criterion based on the angle subtended by the first zero of the diffraction pattern from the center of the diffracting aperture. The determination of the zero of the diffraction pattern is the crucial point for assuring the precision of the criterion. It mainly depends on the dynamical range of the detector. Therefore, the applicability of adequate thresholds for different detector types is discussed. The criterion is also generalized by expressing it in terms of the number of Fresnel zones delimited by the aperture. Simulations are reported for illustrating the feasibility of the criterion. (author)

Stakeholder engagement in comparative effectiveness research: how will we measure success?

Science.gov (United States)

Lavallee, Danielle C; Williams, Carla J; Tambor, Ellen S; Deverka, Patricia A

2012-09-01

Stakeholder engagement in comparative effectiveness research continues to gain national attention. While various methods are used to gather stakeholder expertise and form recommendations, evaluation of the stakeholder experience is often missing. The lack of evaluation prohibits assessing how effective and meaningful engagement practices are for enhancing research efforts and limits the ability to identify areas for future improvement. We propose that an evaluation plan of engagement processes be developed before stakeholder involvement begins and be required as part of a request for proposal or research grant where stakeholder input is being sought. Furthermore, we recommend the inclusion of six meta-criteria that represent normative goals of multiple studies: respect, trust, legitimacy, fairness, competence and accountability. To aid in the development of future evaluations, we have developed definitions for and matched specific examples of measuring each meta-criterion to serve a guide for others in the field.

Using Akaike's information theoretic criterion in mixed-effects modeling of pharmacokinetic data: a simulation study [version 3; referees: 2 approved, 1 approved with reservations

Directory of Open Access Journals (Sweden)

Erik Olofsen

2015-07-01

Full Text Available Akaike's information theoretic criterion for model discrimination (AIC is often stated to "overfit", i.e., it selects models with a higher dimension than the dimension of the model that generated the data. However, with experimental pharmacokinetic data it may not be possible to identify the correct model, because of the complexity of the processes governing drug disposition. Instead of trying to find the correct model, a more useful objective might be to minimize the prediction error of drug concentrations in subjects with unknown disposition characteristics. In that case, the AIC might be the selection criterion of choice. We performed Monte Carlo simulations using a model of pharmacokinetic data (a power function of time with the property that fits with common multi-exponential models can never be perfect - thus resembling the situation with real data. Prespecified models were fitted to simulated data sets, and AIC and AICc (the criterion with a correction for small sample sizes values were calculated and averaged. The average predictive performances of the models, quantified using simulated validation sets, were compared to the means of the AICs. The data for fits and validation consisted of 11 concentration measurements each obtained in 5 individuals, with three degrees of interindividual variability in the pharmacokinetic volume of distribution. Mean AICc corresponded very well, and better than mean AIC, with mean predictive performance. With increasing interindividual variability, there was a trend towards larger optimal models, but with respect to both lowest AICc and best predictive performance. Furthermore, it was observed that the mean square prediction error itself became less suitable as a validation criterion, and that a predictive performance measure should incorporate interindividual variability. This simulation study showed that, at least in a relatively simple mixed-effects modelling context with a set of prespecified models

Consistency of test behaviour and individual difference in prescision of prediction

NARCIS (Netherlands)

Meijer, R.R.

1998-01-01

Ghiselli ((1956, 1960) argued that the precision of prediction on the basis of a test may vary for different individuals. To quantify the individual precision of prediction he compared the observed criterion scores with the expected criterion scores estimated on the basis of the total scores on a

A criterion for the onset of slugging in horizontal stratified air-water countercurrent flow

International Nuclear Information System (INIS)

Chun, Moon-Hyun; Lee, Byung-Ryung; Kim, Yang-Seok

1995-01-01

This paper presents an experimental and theoretical investigation of wave height and transition criterion from wavy to slug flow in horizontal air-water countercurrent stratified flow conditions. A theoretical formula for the wave height in a stratified wavy flow regime has been developed using the concept of total energy balance over a wave crest to consider the shear stress acting on the interface of two fluids. From the limiting condition of the formula for the wave height, a necessary criterion for transition from a stratified wavy flow to a slug flow has been derived. A series of experiments have been conducted changing the non-dimensional water depth and the flow rates of air in a horizontal pipe and a duct. Comparisons between the measured data and the predictions of the present theory show that the agreement is within ±8%

A criterion for the onset of slugging in horizontal stratified air-water countercurrent flow

Energy Technology Data Exchange (ETDEWEB)

Chun, Moon-Hyun; Lee, Byung-Ryung; Kim, Yang-Seok [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)] [and others

1995-09-01

This paper presents an experimental and theoretical investigation of wave height and transition criterion from wavy to slug flow in horizontal air-water countercurrent stratified flow conditions. A theoretical formula for the wave height in a stratified wavy flow regime has been developed using the concept of total energy balance over a wave crest to consider the shear stress acting on the interface of two fluids. From the limiting condition of the formula for the wave height, a necessary criterion for transition from a stratified wavy flow to a slug flow has been derived. A series of experiments have been conducted changing the non-dimensional water depth and the flow rates of air in a horizontal pipe and a duct. Comparisons between the measured data and the predictions of the present theory show that the agreement is within {plus_minus}8%.

Criterion for testing multiparticle negative-partial-transpose entanglement

International Nuclear Information System (INIS)

Zeng, B.; Zhou, D.L.; Zhang, P.; Xu, Z.; You, L.

2003-01-01

We revisit the criterion of multiparticle entanglement based on the overlaps of a given quantum state ρ with maximally entangled states. For a system of m particles, each with N distinct states, we prove that ρ is m-particle negative partial transpose entangled, if there exists a maximally entangled state vertical bar MES>, such that >1/N. While this sufficiency condition is weaker than the Peres-Horodecki criterion in all cases, it applies to multi-particle systems, and becomes especially useful when the number of particles (m) is large. We also consider the converse of this criterion and illustrate its invalidity with counter examples

Burnout and engagement of reformed church ministers

Directory of Open Access Journals (Sweden)

Chenelle Buys

2010-06-01

Research purpose: The objective of this study was to investigate the effects of job-demands and job-resources on ministers’ burnout and engagement. Congregational commitment and health were included as possible consequences of burnout and engagement. Motivation for the study: Ministers’ well-being has become an important topic for both researchers and practitioners. Research design, approach and method: A survey design with a non-probability, purposive voluntary sample of 115 ministers was used. The Job-Demands–Resources Questionnaire, Maslach Burnout Inventory, Work Engagement Scale, General Health Questionnaire, and Congregational Commitment Scale were administered. Main findings: Regression analysis indicated that the pace, amount of work and emotional demands were indicators of burnout while growth opportunities, social support and job significance were indicators of engagement. Furthermore, it was found that exhaustion predicted somatic symptoms and depression, while mental distance predicted depression. Engagement predicted social functioning and affective commitment. Practical implications: Interventions should be implemented to help ministers deal more effectively with any burnout symptoms experienced in order to prevent ministers who are already showing signs of burnout from getting sick to increase their engagement and to rehabilitate individuals who are ill as a result of the work place. Contribution: The study contributes to knowledge regarding the effects of job-demands and resources on the well-being of ministers.

Stress, alcohol use and work engagement among university workers ...

African Journals Online (AJOL)

... workplace alcohol use and work engagement among 228 University of Nigeria, Nsukka, workers. The results of the regression analyses showed that job stress significantly predicted workplace alcohol use (â = .17, p < .01). Workplace alcohol use also significantly predicted employee work engagement (â = -.35, p < .001).

Absorbed in the task : Personality measures predict engagement during task performance as tracked by error negativity and asymmetrical frontal activity

NARCIS (Netherlands)

Tops, Mattie; Boksem, Maarten A. S.

2010-01-01

We hypothesized that interactions between traits and context predict task engagement, as measured by the amplitude of the error-related negativity (ERN), performance, and relative frontal activity asymmetry (RFA). In Study 1, we found that drive for reward, absorption, and constraint independently

Coping and work engagement in selected South African organisations

Directory of Open Access Journals (Sweden)

Sebastiaan Rothmann

2011-10-01

Research purpose: The objective of this study was to investigate the relationship between coping strategies and work engagement in three occupational groups in South Africa. Motivation for the study: There is little understanding of the relationship between effective forms of coping and positive outcomes (like work engagement. Research design, approach and method: The researchers used a survey design. They drew random and stratified samples (N = 3178 from three occupational groups. These were technical employees in an electricity provider, professional and enrolled nurses and police officers. They administered the Coping Orientations to the Problems Experienced (COPE and the Utrecht Work Engagement Scale (UWES. Main findings: The results showed that there was a statistically significant relationship between work engagement, problem-focused coping, positive reinterpretation and growth. In the nursing sample, high problem-focused coping, low avoidance and low ventilation of emotions predicted work engagement best. In the police sample, four coping strategies (problem-focused coping, seeking social support, turning to religion and low ventilation of emotions predicted work engagement best. In the technician sample, problem-focused coping and low ventilation of emotions predicted work engagement best. Practical/managerial implications: Organisations should consider employees’ coping strategies when they introduce interventions to improve work engagement. Contribution/value-add: This study contributes to the knowledge about the relationship between coping strategies and work engagement in South African organisations.

Interpretation of ongoing thermal response tests of vertical (BHE) borehole heat exchangers with predictive uncertainty based stopping criterion

DEFF Research Database (Denmark)

Poulsen, Søren Erbs; Alberdi Pagola, Maria

2015-01-01

A method for real-time interpretation of ongoing thermal response tests of vertical borehole heat exchangers is presented. The method utilizes a statistically based stopping criterion for ongoing tests. The study finds minimum testing times for synthetic and actual TRTs to be in the interval 12–2...

Determination of the initiation of ductile tearing in cracked branch pipes on the basis of a pre-determined criterion using small specimens

International Nuclear Information System (INIS)

Chapuliot, S.; Marie, S.

1999-01-01

This article describes an experimental and numerical study of the initiation conditions of ductile tearing in ferritic materials. An initial criterion J i is determined experimentally using a sufficiently thick CT specimen. The numerical and experimental aspects are then discussed for thinner CT specimen and a method is proposed for determining it in thin test samples. The local ductile tear initiation criterion, which was determined on the basis of 3D finite element calculations, was applied to a cracked branch pipe geometry subjected to out-of-plane bending to compare the load estimates at the start of propagation and the values measured during the test. The results of the comparison were highly satisfactory: the criterion is predictive. (orig.)

Determinants of engagement in mental health consumer-run organizations.

Science.gov (United States)

Brown, Louis Davis; Townley, Greg

2015-04-01

Mental health consumer-run organizations (CROs) are a low-cost, evidence-based strategy for promoting recovery. To increase CRO utilization, characteristics that promote engagement need to be identified and encouraged. The study examined individual and organizational characteristics that predict three types of engagement in CROs-attendance, leadership involvement, and socially supportive involvement. Surveys were administered to 250 CRO members attending 20 CROs. Leaders of each CRO reported organizational characteristics through a separate questionnaire. Multilevel regression models examined relationships between predictors and indicators of CRO engagement. Perceived sense of community was the only characteristic that predicted attendance, leadership involvement, and socially supportive involvement (p<.001). Perceived organizational empowerment, shared leadership, peer counseling, and several demographic characteristics also predicted some measures of engagement. CROs that can effectively promote sense of community, organizational empowerment, shared leadership, and peer counseling may be better able to engage participants. The discussion considers several strategies to enhance these characteristics, such as collectively establishing values and practicing shared decision making.

A comparative study on the forming limit diagram prediction between Marciniak-Kuczynski model and modified maximum force criterion by using the evolving non-associated Hill48 plasticity model

Science.gov (United States)

Shen, Fuhui; Lian, Junhe; Münstermann, Sebastian

2018-05-01

Experimental and numerical investigations on the forming limit diagram (FLD) of a ferritic stainless steel were performed in this study. The FLD of this material was obtained by Nakajima tests. Both the Marciniak-Kuczynski (MK) model and the modified maximum force criterion (MMFC) were used for the theoretical prediction of the FLD. From the results of uniaxial tensile tests along different loading directions with respect to the rolling direction, strong anisotropic plastic behaviour was observed in the investigated steel. A recently proposed anisotropic evolving non-associated Hill48 (enHill48) plasticity model, which was developed from the conventional Hill48 model based on the non-associated flow rule with evolving anisotropic parameters, was adopted to describe the anisotropic hardening behaviour of the investigated material. In the previous study, the model was coupled with the MMFC for FLD prediction. In the current study, the enHill48 was further coupled with the MK model. By comparing the predicted forming limit curves with the experimental results, the influences of anisotropy in terms of flow rule and evolving features on the forming limit prediction were revealed and analysed. In addition, the forming limit predictive performances of the MK and the MMFC models in conjunction with the enHill48 plasticity model were compared and evaluated.

SOCIO-PSYCHOLOGICAL CRITERIONS OF FAMILY LIFESTYLE TYPOLOGY

Directory of Open Access Journals (Sweden)

Yekaterina Anatolievna Yumkina

2015-02-01

Full Text Available The purpose of this article is to present socio-psychological criterions of family lifestyle typology, which were found during theoretical modelling and empirical research work. It is important in fundamental and practical aspects. St-Petersburg students (n = 116, from 19 to 21 years old were examined by special questionnaire «Family relationship and home» (Kunitsi-na V.N., Yumkina Ye.A., 2012 which measures different aspects of family lifestyle. We also used complex of methods that gave us information about personal values, self-rating and parent-child relationships. Dates were divided into six groups according to three main criterions of family lifestyle typology: social environment of family life, family activity, and family interpersonal relationships. There were found statistically significant differences between pairs of group from every criterions. The results can be useful in spheres dealing with family crisis, family development, family traditions etc.

Industry Software Trustworthiness Criterion Research Based on Business Trustworthiness

Science.gov (United States)

Zhang, Jin; Liu, Jun-fei; Jiao, Hai-xing; Shen, Yi; Liu, Shu-yuan

To industry software Trustworthiness problem, an idea aiming to business to construct industry software trustworthiness criterion is proposed. Based on the triangle model of "trustworthy grade definition-trustworthy evidence model-trustworthy evaluating", the idea of business trustworthiness is incarnated from different aspects of trustworthy triangle model for special industry software, power producing management system (PPMS). Business trustworthiness is the center in the constructed industry trustworthy software criterion. Fusing the international standard and industry rules, the constructed trustworthy criterion strengthens the maneuverability and reliability. Quantitive evaluating method makes the evaluating results be intuitionistic and comparable.

Two novel synchronization criterions for a unified chaotic system

International Nuclear Information System (INIS)

Tao Chaohai; Xiong Hongxia; Hu Feng

2006-01-01

Two novel synchronization criterions are proposed in this paper. It includes drive-response synchronization and adaptive synchronization schemes. Moreover, these synchronization criterions can be applied to a large class of chaotic systems and are very useful for secure communication

Predicting glass-forming compositions in the Al-La and Al-La-Ni systems

International Nuclear Information System (INIS)

Gargarella, P.; de Oliveira, M.F.; Kiminami, C.S.; Pauly, S.; Kuehn, U.; Bolfarini, C.; Botta, W.J.; Eckert, J.

2011-01-01

Research highlights: → The glass-forming ability of the Al-La and Al-La-Ni systems was studied using the λ* and the λ.Δe criteria. → Both criteria predicted with just 1% at. of error the best glass-former verified so far in the Al-La system. → Four new glass-former compositions could be predicted in the Al-La-Ni system using the λ.Δe criterion. → The best glass-former reported so far in the Al-La-Ni system was found. - Abstract: In this work, a criterion considering the topological instability (λ) and the differences in the electronegativity of the constituent elements (Δe) was applied to the Al-La and Al-Ni-La systems in order to predict the best glass-forming compositions. The results were compared with literature data and with our own experimental data for the Al-La-Ni system. The alloy described in the literature as the best glass former in the Al-La system is located near the point with local maximum for the λ.Δe criterion. A good agreement was found between the predictions of the λ.Δe criterion and literature data in the Al-La-Ni system, with the region of the best glass-forming ability (GFA) and largest supercooled liquid region (ΔT x ) coinciding with the best compositional region for amorphization indicated by the λ.Δe criterion. Four new glassy compositions were found in the Al-La-Ni system, with the best predicted composition presenting the best glass-forming ability observed so far for this system. Although the λ.Δe criterion needs further refinements for completely describe the glass-forming ability in the Al-La and Al-La-Ni systems, the results demonstrated that this criterion is a good tool to predict new glass-forming compositions.

A scale invariance criterion for LES parametrizations

Directory of Open Access Journals (Sweden)

Urs Schaefer-Rolffs

2015-01-01

Full Text Available Turbulent kinetic energy cascades in fluid dynamical systems are usually characterized by scale invariance. However, representations of subgrid scales in large eddy simulations do not necessarily fulfill this constraint. So far, scale invariance has been considered in the context of isotropic, incompressible, and three-dimensional turbulence. In the present paper, the theory is extended to compressible flows that obey the hydrostatic approximation, as well as to corresponding subgrid-scale parametrizations. A criterion is presented to check if the symmetries of the governing equations are correctly translated into the equations used in numerical models. By applying scaling transformations to the model equations, relations between the scaling factors are obtained by demanding that the mathematical structure of the equations does not change.The criterion is validated by recovering the breakdown of scale invariance in the classical Smagorinsky model and confirming scale invariance for the Dynamic Smagorinsky Model. The criterion also shows that the compressible continuity equation is intrinsically scale-invariant. The criterion also proves that a scale-invariant turbulent kinetic energy equation or a scale-invariant equation of motion for a passive tracer is obtained only with a dynamic mixing length. For large-scale atmospheric flows governed by the hydrostatic balance the energy cascade is due to horizontal advection and the vertical length scale exhibits a scaling behaviour that is different from that derived for horizontal length scales.

Study on criterion for leak before break assessment of pressure pipes

International Nuclear Information System (INIS)

Yang Linjuan

2009-01-01

Based on the elastoplastic fracture mechanics, this paper established the expression formulas of limit buckling pressure P u on the ligament of axial and circumferential surface cracks and the initial pressure for the through cracks P c . A new Leak Before Break (LBB) assessment criterion was put forward to predict the failure mode of pressure pipes, i.e., when P u is less than P c , the pipe will leak; when P u is equal to or larger than P c , the pipe will break, which is verified by the test data reported in literatures. (authors)

Decision criterion dynamics in animals performing an auditory detection task.

Directory of Open Access Journals (Sweden)

Robert W Mill

Full Text Available Classical signal detection theory attributes bias in perceptual decisions to a threshold criterion, against which sensory excitation is compared. The optimal criterion setting depends on the signal level, which may vary over time, and about which the subject is naïve. Consequently, the subject must optimise its threshold by responding appropriately to feedback. Here a series of experiments was conducted, and a computational model applied, to determine how the decision bias of the ferret in an auditory signal detection task tracks changes in the stimulus level. The time scales of criterion dynamics were investigated by means of a yes-no signal-in-noise detection task, in which trials were grouped into blocks that alternately contained easy- and hard-to-detect signals. The responses of the ferrets implied both long- and short-term criterion dynamics. The animals exhibited a bias in favour of responding "yes" during blocks of harder trials, and vice versa. Moreover, the outcome of each single trial had a strong influence on the decision at the next trial. We demonstrate that the single-trial and block-level changes in bias are a manifestation of the same criterion update policy by fitting a model, in which the criterion is shifted by fixed amounts according to the outcome of the previous trial and decays strongly towards a resting value. The apparent block-level stabilisation of bias arises as the probabilities of outcomes and shifts on single trials mutually interact to establish equilibrium. To gain an intuition into how stable criterion distributions arise from specific parameter sets we develop a Markov model which accounts for the dynamic effects of criterion shifts. Our approach provides a framework for investigating the dynamics of decisions at different timescales in other species (e.g., humans and in other psychological domains (e.g., vision, memory.

Fingerprint verification prediction model in hand dermatitis.

Science.gov (United States)

Lee, Chew K; Chang, Choong C; Johor, Asmah; Othman, Puwira; Baba, Roshidah

2015-07-01

Hand dermatitis associated fingerprint changes is a significant problem and affects fingerprint verification processes. This study was done to develop a clinically useful prediction model for fingerprint verification in patients with hand dermatitis. A case-control study involving 100 patients with hand dermatitis. All patients verified their thumbprints against their identity card. Registered fingerprints were randomized into a model derivation and model validation group. Predictive model was derived using multiple logistic regression. Validation was done using the goodness-of-fit test. The fingerprint verification prediction model consists of a major criterion (fingerprint dystrophy area of ≥ 25%) and two minor criteria (long horizontal lines and long vertical lines). The presence of the major criterion predicts it will almost always fail verification, while presence of both minor criteria and presence of one minor criterion predict high and low risk of fingerprint verification failure, respectively. When none of the criteria are met, the fingerprint almost always passes the verification. The area under the receiver operating characteristic curve was 0.937, and the goodness-of-fit test showed agreement between the observed and expected number (P = 0.26). The derived fingerprint verification failure prediction model is validated and highly discriminatory in predicting risk of fingerprint verification in patients with hand dermatitis. © 2014 The International Society of Dermatology.

Blind equalization with criterion with memory nonlinearity

Science.gov (United States)

Chen, Yuanjie; Nikias, Chrysostomos L.; Proakis, John G.

1992-06-01

Blind equalization methods usually combat the linear distortion caused by a nonideal channel via a transversal filter, without resorting to the a priori known training sequences. We introduce a new criterion with memory nonlinearity (CRIMNO) for the blind equalization problem. The basic idea of this criterion is to augment the Godard [or constant modulus algorithm (CMA)] cost function with additional terms that penalize the autocorrelations of the equalizer outputs. Several variations of the CRIMNO algorithms are derived, with the variations dependent on (1) whether the empirical averages or the single point estimates are used to approximate the expectations, (2) whether the recent or the delayed equalizer coefficients are used, and (3) whether the weights applied to the autocorrelation terms are fixed or are allowed to adapt. Simulation experiments show that the CRIMNO algorithm, and especially its adaptive weight version, exhibits faster convergence speed than the Godard (or CMA) algorithm. Extensions of the CRIMNO criterion to accommodate the case of correlated inputs to the channel are also presented.

Importance biasing quality criterion based on contribution response theory

International Nuclear Information System (INIS)

Borisov, N.M.; Panin, M.P.

2001-01-01

The report proposes a visual criterion of importance biasing both of forward and adjoint simulation. The similarity of contribution Monte Carlo and importance biasing random collision event distribution is proved. The conservation of total number of random trajectory crossings of surfaces, which separate the source and the detector is proposed as importance biasing quality criterion. The use of this criterion is demonstrated on the example of forward vs. adjoint importance biasing in gamma ray deep penetration problem. The larger amount of published data on forward field characteristics than on adjoint leads to the more accurate approximation of adjoint importance function in comparison to forward, for it adjoint importance simulation is more effective than forward. The proposed criterion indicates it visually, showing the most uniform distribution of random trajectory crossing events for the most effective importance biasing parameters and pointing to the direction of tuning importance biasing parameters. (orig.)

The Prediction of Metal Slopping in LD Converter on Base an Acoustic Signal

Directory of Open Access Journals (Sweden)

Kostúr, K.

2006-01-01

Full Text Available The negative influences of slopping in a BOF are pollution to the environment. They give lower yield and cause equipment damage. The prediction of these phenomena is based on information processing from the measuring microphone. The change of frequency in certain range is done by a signal for the prediction of slopping. In this paper two methods for prediction of slopping are described. The first method is based on measuring and processing of sound emitted from the vessel during the blow. The second method utilizes Fourier’s transformation for processing of acoustic signal from sonic meter. The success rate of prediction has been evaluated by help of five criterions. It is possible to forecast the slopping on selected frequency (band. It is the essence of the second method, because this method has high success (criterion K1. Note, that criterion K5 defines acknowledgment of duration slopping. This criterion has the highest value.

Criterion of damage beginning: experimental identification for laminate composite

International Nuclear Information System (INIS)

Thiebaud, F.; Perreux, D.; Varchon, D.; Lebras, J.

1996-01-01

The aim of this study is to propose a criterion of damage beginning for laminate composite. The materials is a glass-epoxy laminate [+55 deg.,-55 deg.[ n performed by winding filament process. First of all a description of the damage is performed and allows to define a damage variable. Thanks to the potential of free energy, an associated variable is defined. The damage criterion is written by using this last one. The parameter of the criterion is identified using mechanical and acoustical methods. The result is compared and exhibit a good agreement. (authors). 13 refs., 5 figs

The free growth criterion for grain initiation in TiB 2 inoculated γ-titanium aluminide based alloys

Science.gov (United States)

Gosslar, D.; Günther, R.

2014-02-01

γ-titanium aluminide (γ-TiAl) based alloys enable for the design of light-weight and high-temperature resistant engine components. This work centers on a numerical study of the condition for grain initiation during solidification of TiB2 inoculated γ-TiAl based alloys. Grain initiation is treated according to the so-called free growth criterion. This means that the free growth barrier for grain initiation is determined by the maximum interfacial mean curvature between a nucleus and the melt. The strategy presented in this paper relies on iteratively increasing the volume of a nucleus, which partially wets a hexagonal TiB2 crystal, minimizing the interfacial energy and calculating the corresponding interfacial curvature. The hereby obtained maximum curvature yields a scaling relation between the size of TiB2 crystals and the free growth barrier. Comparison to a prototypical TiB2 crystal in an as cast γ-TiAl based alloy allowed then to predict the free growth barrier prevailing under experimental conditions. The validity of the free growth criterion is discussed by an interfacial energy criterion.

Latent profiles of nonresidential father engagement six years after divorce predict long-term offspring outcomes.

Science.gov (United States)

Modecki, Kathryn Lynn; Hagan, Melissa J; Sandler, Irwin; Wolchik, Sharlene A

2015-01-01

This study examined profiles of nonresidential father engagement (i.e., support to the adolescent, contact frequency, remarriage, relocation, and interparental conflict) with their adolescent children (N = 156) 6 to 8 years following divorce and the prospective relation between these profiles and the psychosocial functioning of their offspring, 9 years later. Parental divorce occurred during late childhood to early adolescence; indicators of nonresidential father engagement were assessed during adolescence, and mental health problems and academic achievement of offspring were assessed 9 years later in young adulthood. Three profiles of father engagement were identified in our sample of mainly White, non-Hispanic divorced fathers: Moderate Involvement/Low Conflict, Low Involvement/Moderate Conflict, and High Involvement/High Conflict. Profiles differentially predicted offspring outcomes 9 years later when they were young adults, controlling for quality of the mother-adolescent relationship, mother's remarriage, mother's income, and gender, age, and offspring mental health problems in adolescence. Offspring of fathers characterized as Moderate Involvement/Low Conflict had the highest academic achievement and the lowest number of externalizing problems 9 years later compared to offspring whose fathers had profiles indicating either the highest or lowest levels of involvement but higher levels of conflict. Results indicate that greater paternal psychosocial support and more frequent father-adolescent contact do not outweigh the negative impact of interparental conflict on youth outcomes in the long term. Implications of findings for policy and intervention are discussed.

The adolescents’ school engagement: Assessment of its dimensions

Directory of Open Access Journals (Sweden)

José Manuel TOMÁS

2016-06-01

Full Text Available A topic that in the last years is getting relevance in school and students research is school engagement. This topic has been related, among other important constructs, with burnout of teachers and students, school performance, satisfaction with the school, behavioral disruption, goal orientation and motivational climate in the classroom, students-teachers relationships, and life satisfaction of the students. School engagement may be defined as the participation of the student in academic achievements, and it is understood as a multidimensional construct. The most repeated typology of dimensions recognizes three specific and overlapping dimensions: cognitive, behavioral, and emotional (affective. Frequently, education professionals have reported the lack of instruments to measure some students’ characteristics and psychosocial and behavioral variables in the classroom, as it is the case of school engagement. Recently, a fourth new dimension, personal agency, has been proposed (Reeve and Tseng, 2011. Veiga (2013 has been the first to present a self-report instrument, in Portuguese, to measure these four components, the Student Engagement Scale-4 dimensions (ses-4ds. Taken all this into account, the aim of this research was to study the reliability and validity of the aforementioned scale in two versions, Spanish and Portuguese, in large samples from the Dominican Republic and Angola. Results have shown a clear factor structure (after deleting two items, and adequate criterion-related and nomological validity. Accordingly, the ses-4d scale was considered a valid instrument to be applied in studies measuring school engagement of teenagers. 

A multiple model approach to respiratory motion prediction for real-time IGRT

International Nuclear Information System (INIS)

Putra, Devi; Haas, Olivier C L; Burnham, Keith J; Mills, John A

2008-01-01

Respiration induces significant movement of tumours in the vicinity of thoracic and abdominal structures. Real-time image-guided radiotherapy (IGRT) aims to adapt radiation delivery to tumour motion during irradiation. One of the main problems for achieving this objective is the presence of time lag between the acquisition of tumour position and the radiation delivery. Such time lag causes significant beam positioning errors and affects the dose coverage. A method to solve this problem is to employ an algorithm that is able to predict future tumour positions from available tumour position measurements. This paper presents a multiple model approach to respiratory-induced tumour motion prediction using the interacting multiple model (IMM) filter. A combination of two models, constant velocity (CV) and constant acceleration (CA), is used to capture respiratory-induced tumour motion. A Kalman filter is designed for each of the local models and the IMM filter is applied to combine the predictions of these Kalman filters for obtaining the predicted tumour position. The IMM filter, likewise the Kalman filter, is a recursive algorithm that is suitable for real-time applications. In addition, this paper proposes a confidence interval (CI) criterion to evaluate the performance of tumour motion prediction algorithms for IGRT. The proposed CI criterion provides a relevant measure for the prediction performance in terms of clinical applications and can be used to specify the margin to accommodate prediction errors. The prediction performance of the IMM filter has been evaluated using 110 traces of 4-minute free-breathing motion collected from 24 lung-cancer patients. The simulation study was carried out for prediction time 0.1-0.6 s with sampling rates 3, 5 and 10 Hz. It was found that the prediction of the IMM filter was consistently better than the prediction of the Kalman filter with the CV or CA model. There was no significant difference of prediction errors for the

Human amygdala engagement moderated by early life stress exposure is a biobehavioral target for predicting recovery on antidepressants.

Science.gov (United States)

Goldstein-Piekarski, Andrea N; Korgaonkar, Mayuresh S; Green, Erin; Suppes, Trisha; Schatzberg, Alan F; Hastie, Trevor; Nemeroff, Charles B; Williams, Leanne M

2016-10-18

Amygdala circuitry and early life stress (ELS) are both strongly and independently implicated in the neurobiology of depression. Importantly, animal models have revealed that the contribution of ELS to the development and maintenance of depression is likely a consequence of structural and physiological changes in amygdala circuitry in response to stress hormones. Despite these mechanistic foundations, amygdala engagement and ELS have not been investigated as biobehavioral targets for predicting functional remission in translational human studies of depression. Addressing this question, we integrated human neuroimaging and measurement of ELS within a controlled trial of antidepressant outcomes. Here we demonstrate that the interaction between amygdala activation engaged by emotional stimuli and ELS predicts functional remission on antidepressants with a greater than 80% cross-validated accuracy. Our model suggests that in depressed people with high ELS, the likelihood of remission is highest with greater amygdala reactivity to socially rewarding stimuli, whereas for those with low-ELS exposure, remission is associated with lower amygdala reactivity to both rewarding and threat-related stimuli. This full model predicted functional remission over and above the contribution of demographics, symptom severity, ELS, and amygdala reactivity alone. These findings identify a human target for elucidating the mechanisms of antidepressant functional remission and offer a target for developing novel therapeutics. The results also offer a proof-of-concept for using neuroimaging as a target for guiding neuroscience-informed intervention decisions at the level of the individual person.

The impact of a total reward system of work engagement

Directory of Open Access Journals (Sweden)

Crystal Hoole

2016-11-01

Research purpose: The overall purpose of this study was to explore the relationship between total rewards and work engagement in a South African context and to determine which reward categories predict work engagement. The study further endeavoured to determine whether gender and age had a moderating effect on the relationship between total rewards and engagement. Motivation for the study: Statistics report that less than 30% of all working people are optimally engaged in their work. Considering that individuals spend more than a third of their lives at work committing themselves emotionally, physically and psychologically – research indicates that employees are no longer satisfied with traditional reward systems and want to feel valued and appreciated. Research approach, design and method: In this quantitative, cross-sectional research design using a non-probability convenience and purposive sampling strategy, 318 questionnaires were collected and analysed from financial institutions in Gauteng in which opinions were sought on the importance of different types of rewards structures and preferences, and how engaged they are in their workplace. The 17-item UWES and Nienaber total reward preference model were the chosen measuring instruments. Main findings: A small statistically significant correlation (r = 0.25; p < 0.05; small effect was found between total rewards and work engagement, and 12% of the variance of work engagement was explained. Only performance and career management significantly predicted work engagement. Practical/Managerial implications: Although small, the significant correlation between total rewards and work engagement implies that total rewards are important motivators for employees in the workplace. Of the total rewards scales tested, only performance and career management significantly predicted work engagement, suggesting that more research is needed. Organisations seeking to implement total reward strategies should pay specific

General stability criterion for inviscid parallel flow

International Nuclear Information System (INIS)

Sun Liang

2007-01-01

Arnol'd's second stability theorem is approached from an elementary point of view. First, a sufficient criterion for stability is found analytically as either -μ 1 s ) s ) in the flow, where U s is the velocity at the inflection point, and μ 1 is the eigenvalue of Poincare's problem. Second, this criterion is generalized to barotropic geophysical flows in the β plane. And the connections between present criteria and Arnol'd's nonlinear criteria are also discussed. The proofs are completely elementary and so could be used to teach undergraduate students

The Concept of Performance Levels in Criterion-Referenced Assessment.

Science.gov (United States)

Hewitson, Mal

The concept of performance levels in criterion-referenced assessment is explored by applying the idea to different types of tests commonly used in schools, mastery tests (including diagnostic tests) and achievement tests. In mastery tests, a threshold performance standard must be established for each criterion. Attainment of this threshold…

A criterion for heated pipe design by linear electric resistances

International Nuclear Information System (INIS)

Bloch, M.; Cruz, J.R.B.

1984-01-01

A criterion for linear eletrical elements instalation on horizontal tubes is obtainned in this work. This criterion is based upon the calculation of the thermal stresses caused by the non uniform temperature distribution in the tube cross section. The finite difference method and the SAP IV computer code are both used in the calculations. The criterion is applied to the thermal circuits of the IEN which has tube diameter varying from φ 1/2 in till φ 8 in. (author) [pt

Novel global robust stability criterion for neural networks with delay

International Nuclear Information System (INIS)

Singh, Vimal

2009-01-01

A novel criterion for the global robust stability of Hopfield-type interval neural networks with delay is presented. An example illustrating the improvement of the present criterion over several recently reported criteria is given.

An extension of theoretical analysis for the onset of slugging criterion in horizontal stratified air-water countercurrent flow

International Nuclear Information System (INIS)

Lee, Byung Ryung

1997-02-01

This paper presents an experimental and theoretical investigation of interfacial friction factor, wave height and transition criterion from wavy to slug flow in a long horizontal air-water countercurrent stratified flow condition. A series of experiments have been conducted in adiabatic countercurrent stratified flow with the round pipe and rectangular duct test section to develop the interfacial friction factor and the criterion of onset of slugging in horizontal air-water countercurrent stratified flow. An adiabatic semi-empirical correlation for interfacial friction factor has been developed based on the surface roughness concept. A comparison of the measured data in this study and of other investigators with the predictions of the present correlation shows that the agreement is within ±30% error, and that the present correlation is applicable to a broader range of water flow rate than the correlations of previous investigators. The theories which can calculate the wave height and criteria of onset of slug flow in a stratified wavy flow regime have been developed based on the concept of total energy conservation and also wave theory. This theoretical criteria agree better with the measured data than the other criteria available in the literature, but the criteria range about 92∼107% of the measured data. An empirical formula for the criterion has been also developed and compared with the formula in the literatures. Comparison between the measured data and the predictions of the present theory shows that the agreement is within ±8%

Appraisal and Reliability of Variable Engagement Model Prediction ...

African Journals Online (AJOL)

The variable engagement model based on the stress - crack opening displacement relationship and, which describes the behaviour of randomly oriented steel fibres composite subjected to uniaxial tension has been evaluated so as to determine the safety indices associated when the fibres are subjected to pullout and with ...

Joined application of a multiaxial critical plane criterion and a strain energy density criterion in low-cycle fatigue

Directory of Open Access Journals (Sweden)

Andrea Carpinteri

2017-07-01

Full Text Available In the present paper, the multiaxial fatigue life assessment of notched structural components is performed by employing a strain-based multiaxial fatigue criterion. Such a criterion, depending on the critical plane concept, is extended by implementing the control volume concept reated to the Strain Energy Density (SED approach: a material point located at a certain distance from the notch tip is assumed to be the verification point where to perform the above assessment. Such a distance, measured along the notch bisector, is a function of both the biaxiality ratio (defined as the ratio between the applied shear stress amplitude and the normal stress amplitude and the control volume radii under Mode I and Mode III. Once the position of the verification point is determined, the fatigue lifetime is assessed through an equivalent strain amplitude, acting on the critical plane, together with a unique material reference curve (i.e. the Manson-Coffin curve. Some uniaxial and multiaxial fatigue data related to V-notched round bars made of titanium grade 5 alloy (Ti-6Al-4V are examined to validate the present criterion.

Distance criterion for hydrogen bond

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Distance criterion for hydrogen bond. In a D-H ...A contact, the D...A distance must be less than the sum of van der Waals Radii of the D and A atoms, for it to be a hydrogen bond.

P2-17: Individual Differences in Dynamic Criterion Shifts during Perceptual Decision Making

Directory of Open Access Journals (Sweden)

Issac Rhim

2012-10-01

Full Text Available Perceptual decision-making involves placing an optimal criterion on the axis of encoded sensory evidence to maximize outcomes for choices. Optimal criterion setting becomes critical particularly when neural representations of sensory inputs are noisy and feedbacks for perceptual choices vary over time in an unpredictable manner. Here we monitored time courses of decision criteria that are adopted by human subjects while abruptly shifting the criterion of stochastic feedback to perceptual choices with certain amounts in an unpredictable direction and at an unpredictable point of time. Subjects viewed a brief (0.3 s, thin (.07 deg annulus around the fixation and were forced to judge whether the annulus was smaller or larger than an unknown boundary. We estimated moment-to-moment criteria by fitting a cumulative Gaussian function to the data within a sliding window of trials that are locked to a shift in feedback criterion. Unpredictable shifts in feedback criterion successfully induced shifts in actual decision criterion towards an optimal criterion for many of subjects, but with time delay and amount of shifts varying across individual subjects. There were disproportionately more numbers of overshooters (reaching and then surpassing the optimal criterion required than undershooters (subpar reach, with a significant anti-correlation with sensory sensitivity. To find a mechanism that generates these individual differences, we developed a dynamic criterion learning model by modifying a reinforcement learning model, which assumes that a criterion is adjusted every trial by a weighted discrepancy between actual and expected rewards.

Criterion for the onset of quench for low-flow reflood

International Nuclear Information System (INIS)

Hsu, Y.Y.; Young, M.W.

1982-07-01

This study provides a criterion for the onset of quench for low flow reflood. The criterion is a combination of two conditions: T/sub clad/ < T/sub limiting quench/ where T = Temperature, and α < 0.95 where α = void fraction. This criterion was obtained by examining temperature data from tests simulating PWR reflood, such as FLECHT, THTF, PBF, CCTF, and FEBA tests, with void fraction data from CCTF, FEBA, and FLECHT low flood tests. The data show that quenching initiated at α = 0.95 and that the majority of quench occurred at void fractions near 0.85. The results show that rods can be completely quenched by entrained droplets even if the collapsed liquid level does not advance. A thorough discussion of the analysis which supports this quench criterion is given in the text of this report

A food-predictive cue attributed with incentive salience engages subcortical afferents and efferents of the paraventricular nucleus of the thalamus.

Science.gov (United States)

Haight, Joshua L; Fuller, Zachary L; Fraser, Kurt M; Flagel, Shelly B

2017-01-06

The paraventricular nucleus of the thalamus (PVT) has been implicated in behavioral responses to reward-associated cues. However, the precise role of the PVT in these behaviors has been difficult to ascertain since Pavlovian-conditioned cues can act as both predictive and incentive stimuli. The "sign-tracker/goal-tracker" rat model has allowed us to further elucidate the role of the PVT in cue-motivated behaviors, identifying this structure as a critical component of the neural circuitry underlying individual variation in the propensity to attribute incentive salience to reward cues. The current study assessed differences in the engagement of specific PVT afferents and efferents in response to presentation of a food-cue that had been attributed with only predictive value or with both predictive and incentive value. The retrograde tracer fluorogold (FG) was injected into the PVT or the nucleus accumbens (NAc) of rats, and cue-induced c-Fos in FG-labeled cells was quantified. Presentation of a predictive stimulus that had been attributed with incentive value elicited c-Fos in PVT afferents from the lateral hypothalamus, medial amygdala (MeA), and the prelimbic cortex (PrL), as well as posterior PVT efferents to the NAc. PVT afferents from the PrL also showed elevated c-Fos levels following presentation of a predictive stimulus alone. Thus, presentation of an incentive stimulus results in engagement of subcortical brain regions; supporting a role for the hypothalamic-thalamic-striatal axis, as well as the MeA, in mediating responses to incentive stimuli; whereas activity in the PrL to PVT pathway appears to play a role in processing the predictive qualities of reward-paired stimuli. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Self-Adjointness Criterion for Operators in Fock Spaces

International Nuclear Information System (INIS)

Falconi, Marco

2015-01-01

In this paper we provide a criterion of essential self-adjointness for operators in the tensor product of a separable Hilbert space and a Fock space. The class of operators we consider may contain a self-adjoint part, a part that preserves the number of Fock space particles and a non-diagonal part that is at most quadratic with respect to the creation and annihilation operators. The hypotheses of the criterion are satisfied in several interesting applications

Criterion-based laparoscopic training reduces total training time

OpenAIRE

Brinkman, Willem M.; Buzink, Sonja N.; Alevizos, Leonidas; de Hingh, Ignace H. J. T.; Jakimowicz, Jack J.

2011-01-01

Introduction The benefits of criterion-based laparoscopic training over time-oriented training are unclear. The purpose of this study is to compare these types of training based on training outcome and time efficiency. Methods During four training sessions within 1 week (one session per day) 34 medical interns (no laparoscopic experience) practiced on two basic tasks on the Simbionix LAP Mentor virtual-reality (VR) simulator: ‘clipping and grasping’ and ‘cutting’. Group C (criterion-based) (N...

The precautionary principle as a rational decision criterion

International Nuclear Information System (INIS)

Hovi, Jon

2001-12-01

The paper asks if the precautionary principle may be seen as a rational decision criterion. Six main questions are discussed. 1. Does the principle basically represent a particular set of political options or is it a genuine decision criterion? 2. If it is the latter, can it be reduced to any of the existing criteria for decision making under uncertainty? 3. In what kinds of situation is the principle applicable? 4. What is the relation between the precautionary principle and other principles for environmental regulation? 5. How plausible is the principle's claim that the burden of proof should be reversed? 6. Do the proponents of environmental regulation carry no burden of proof at all? A main conclusion is that, for now at least, the principle contains too many unclear elements to satisfy the requirements of precision and consistency that should reasonably be satisfied by a rational decision criterion. (author)

Probabilistic interpretation of the reduction criterion for entanglement

International Nuclear Information System (INIS)

Zhang, Zhengmin; Luo, Shunlong

2007-01-01

Inspired by the idea of conditional probabilities, we introduce a variant of conditional density operators. But unlike the conditional probabilities which are bounded by 1, the conditional density operators may have eigenvalues exceeding 1 for entangled states. This has the consequence that although any bivariate classical probability distribution has a natural separable decomposition in terms of conditional probabilities, we do not have a quantum analogue of this separable decomposition in general. The 'nonclassical' eigenvalues of conditional density operators are indications of entanglement. The resulting separability criterion turns out to be equivalent to the reduction criterion introduced by Horodecki [Phys. Rev. A 59, 4206 (1999)] and Cerf et al. [Phys. Rev. A 60, 898 (1999)]. This supplies an intuitive probabilistic interpretation for the reduction criterion. The conditional density operators are also used to define a form of quantum conditional entropy which provides an alternative mechanism to reveal quantum discord

Slope Safety Factor Calculations With Non-Linear Yield Criterion Using Finite Elements

DEFF Research Database (Denmark)

Clausen, Johan; Damkilde, Lars

2006-01-01

The factor of safety for a slope is calculated with the finite element method using a non-linear yield criterion of the Hoek-Brown type. The parameters of the Hoek-Brown criterion are found from triaxial test data. Parameters of the linear Mohr-Coulomb criterion are calibrated to the same triaxial...... are carried out at much higher stress levels than present in a slope failure, this leads to the conclusion that the use of the non-linear criterion leads to a safer slope design...

Geophysicists' views about public engagement

Science.gov (United States)

Besley, J. C.; Dudo, A.; Yuan, S.

2016-12-01

The proposed talk would present the results of 2016 survey of American Geophysical Union members (n = 2040) about public engagement. This survey took place as part of a broader, NSF funded, study of engagement views across eight different U.S.-based scientific societies. The presentation would include data about geophysicists' past engagement behavior and willingness to engage alongside data about engagement attitudes, perceived norms (i.e. beliefs about whether peers engage and value engagement), and perceived efficacy (i.e., scientists' beliefs about their own communication skills and the impact of engagement). The presentation would also include results that describe scientists' overall goals for engagement (e.g., increasing support for specific policy positions, changing citizen behavior, etc.), as well as their communication-specific objectives (e.g., increasing knowledge, increase excitement, etc.). All of the results would be put in the context of equivalent results from scientists from seven other societies across a variety of fields, including chemistry, biology, and the social sciences. Three themes that would be emphasized in the presentation include (1) the fact that there are substantial commonalities in engagement views across scientific fields, (2) the important role that perceived engagement skill (efficacy) appears to play in predicting engagement willingness, and (3) a lack of evidence that scientists are thinking about engagement in strategic ways. Strategic engagement, in this regard, would involve setting clear goals and then choosing activities that the social science of science communication suggests might allow one to achieve those goals. The presentation would conclude with thoughts about what might be done to improve the effectiveness of science communication training.

A Criterion to Identify Maximally Entangled Four-Qubit State

International Nuclear Information System (INIS)

Zha Xinwei; Song Haiyang; Feng Feng

2011-01-01

Paolo Facchi, et al. [Phys. Rev. A 77 (2008) 060304(R)] presented a maximally multipartite entangled state (MMES). Here, we give a criterion for the identification of maximally entangled four-qubit states. Using this criterion, we not only identify some existing maximally entangled four-qubit states in the literature, but also find several new maximally entangled four-qubit states as well. (general)

A Joint Optimization Criterion for Blind DS-CDMA Detection

Directory of Open Access Journals (Sweden)

Sergio A. Cruces-Alvarez

2007-01-01

Full Text Available This paper addresses the problem of the blind detection of a desired user in an asynchronous DS-CDMA communications system with multipath propagation channels. Starting from the inverse filter criterion introduced by Tugnait and Li in 2001, we propose to tackle the problem in the context of the blind signal extraction methods for ICA. In order to improve the performance of the detector, we present a criterion based on the joint optimization of several higher-order statistics of the outputs. An algorithm that optimizes the proposed criterion is described, and its improved performance and robustness with respect to the near-far problem are corroborated through simulations. Additionally, a simulation using measurements on a real software-radio platform at 5 GHz has also been performed.

A Joint Optimization Criterion for Blind DS-CDMA Detection

Science.gov (United States)

Durán-Díaz, Iván; Cruces-Alvarez, Sergio A.

2006-12-01

This paper addresses the problem of the blind detection of a desired user in an asynchronous DS-CDMA communications system with multipath propagation channels. Starting from the inverse filter criterion introduced by Tugnait and Li in 2001, we propose to tackle the problem in the context of the blind signal extraction methods for ICA. In order to improve the performance of the detector, we present a criterion based on the joint optimization of several higher-order statistics of the outputs. An algorithm that optimizes the proposed criterion is described, and its improved performance and robustness with respect to the near-far problem are corroborated through simulations. Additionally, a simulation using measurements on a real software-radio platform at 5 GHz has also been performed.

Three-Dimensional Dynamic Rupture in Brittle Solids and the Volumetric Strain Criterion

Science.gov (United States)

Uenishi, K.; Yamachi, H.

2017-12-01

As pointed out by Uenishi (2016 AGU Fall Meeting), source dynamics of ordinary earthquakes is often studied in the framework of 3D rupture in brittle solids but our knowledge of mechanics of actual 3D rupture is limited. Typically, criteria derived from 1D frictional observations of sliding materials or post-failure behavior of solids are applied in seismic simulations, and although mode-I cracks are frequently encountered in earthquake-induced ground failures, rupture in tension is in most cases ignored. Even when it is included in analyses, the classical maximum principal tensile stress rupture criterion is repeatedly used. Our recent basic experiments of dynamic rupture of spherical or cylindrical monolithic brittle solids by applying high-voltage electric discharge impulses or impact loads have indicated generation of surprisingly simple and often flat rupture surfaces in 3D specimens even without the initial existence of planes of weakness. However, at the same time, the snapshots taken by a high-speed digital video camera have shown rather complicated histories of rupture development in these 3D solid materials, which seem to be difficult to be explained by, for example, the maximum principal stress criterion. Instead, a (tensile) volumetric strain criterion where the volumetric strain (dilatation or the first invariant of the strain tensor) is a decisive parameter for rupture seems more effective in computationally reproducing the multi-directionally propagating waves and rupture. In this study, we try to show the connection between this volumetric strain criterion and other classical rupture criteria or physical parameters employed in continuum mechanics, and indicate that the criterion has, to some degree, physical meanings. First, we mathematically illustrate that the criterion is equivalent to a criterion based on the mean normal stress, a crucial parameter in plasticity. Then, we mention the relation between the volumetric strain criterion and the

Latent profiles of non-residential father engagement six years after divorce predict long term offspring outcomes

Science.gov (United States)

Modecki, Kathryn Lynn; Hagan, Melissa; Sandler, Irwin; Wolchik, Sharlene

2014-01-01

This study examined profiles of non-residential father engagement (i.e., support to the adolescent, contact frequency, remarriage, relocation, and interparental conflict) with their adolescent children (N = 156) six to eight years following divorce and the prospective relation between these profiles and the psychosocial functioning of their offspring, nine years later. Parental divorce occurred during late childhood to early adolescence; indicators of non-residential father engagement were assessed during adolescence, and mental health problems and academic achievement of offspring were assessed nine years later in young adulthood. Three profiles of father engagement were identified in our sample of mainly White, non-Hispanic divorced fathers: Moderate Involvement/Low Conflict, Low Involvement/Moderate Conflict, and High Involvement/High Conflict. Profiles differentially predicted offspring outcomes nine years later when they were young adults, controlling for quality of the mother-adolescent relationship, mother’s remarriage, mother’s income, and gender, age and offspring mental health problems in adolescence. Offspring of fathers characterized as Moderate Involvement/Low Conflict had the highest academic achievement and the lowest number of externalizing problems nine years later compared to offspring whose fathers had profiles indicating either the highest or lowest levels of involvement but higher levels of conflict. Results indicate that greater paternal psychosocial support and more frequent father-adolescent contact do not outweigh the negative impact of interparental conflict on youth outcomes in the long-term. Implications of findings for policy and intervention are discussed. PMID:24484456

Sampling Criterion for EMC Near Field Measurements

DEFF Research Database (Denmark)

Franek, Ondrej; Sørensen, Morten; Ebert, Hans

2012-01-01

An alternative, quasi-empirical sampling criterion for EMC near field measurements intended for close coupling investigations is proposed. The criterion is based on maximum error caused by sub-optimal sampling of near fields in the vicinity of an elementary dipole, which is suggested as a worst......-case representative of a signal trace on a typical printed circuit board. It has been found that the sampling density derived in this way is in fact very similar to that given by the antenna near field sampling theorem, if an error less than 1 dB is required. The principal advantage of the proposed formulation is its...

A new objective criterion for IRIS localization

International Nuclear Information System (INIS)

Basit, A.

2010-01-01

Iris localization is the most important step in iris recognition systems. For commonly used databases, exact data is not given which describe the true results of localization. To cope with this problem a new objective criterion for iris localization is proposed in this paper based on our visual system. A specific number of points are selected on pupil boundary, iris boundary, upper eyelid and lower eyelid using the original image and then distance from these points to the result of complete iris localization has been calculated. If the determined distance is below a certain threshold then iris localization is considered correct. Experimental results show that proposed criterion is very effective. (author)

Criterion-based clinical audit in obstetrics: bridging the quality gap?

Science.gov (United States)

Graham, W J

2009-06-01

The Millennium Development Goal 5 - reducing maternal mortality by 75% - is unlikely to be met globally and for the majority of low-income countries. At this time of heightened concern to scale-up services for mothers and babies, it is crucial that not only shortfalls in the quantity of care - in terms of location and financial access - are addressed, but also the quality. Reductions in maternal and perinatal mortality in the immediate term depend in large part on the timely delivery of effective practices in the management of life-threatening complications. Such practices require a functioning health system - including skilled and motivated providers engaged with the women and communities whom they serve. Assuring the quality of this system, the services and the care that women receive requires many inputs, including effective and efficient monitoring mechanisms. The purpose of this article is to summarise the practical steps involved in applying one such mechanism, criterion-based clinical audit (CBCA), and to highlight recent lessons from its application in developing countries. Like all audit tools, the ultimate worth of CBCA relates to the action it stimulates in the health system and among providers.

A mixed methods exploration of the team and organizational factors that may predict new graduate nurse engagement in collaborative practice.

Science.gov (United States)

Pfaff, Kathryn A; Baxter, Pamela E; Ploeg, Jenny; Jack, Susan M

2014-03-01

Although engagement in collaborative practice is reported to support the role transition and retention of new graduate (NG) nurses, it is not known how to promote collaborative practice among these nurses. This mixed methods study explored the team and organizational factors that may predict NG nurse engagement in collaborative practice. A total of 514 NG nurses from Ontario, Canada completed the Collaborative Practice Assessment Tool. Sixteen NG nurses participated in follow-up interviews. The team and organizational predictors of NG engagement in collaborative practice were as follows: satisfaction with the team (β = 0.278; p = 0.000), number of team strategies (β = 0.338; p = 0.000), participation in a mentorship or preceptorship experience (β = 0.137; p = 0.000), accessibility of manager (β = 0.123; p = 0.001), and accessibility and proximity of educator or professional practice leader (β = 0.126; p = 0.001 and β = 0.121; p = 0.002, respectively). Qualitative analysis revealed the team facilitators to be respect, team support and face-to-face interprofessional interactions. Organizational facilitators included supportive leadership, participation in a preceptorship or mentorship experience and time. Interventions designed to facilitate NG engagement in collaborative practice should consider these factors.

Student engagement and its relationship with early high school dropout.

Science.gov (United States)

Archambault, Isabelle; Janosz, Michel; Fallu, Jean-Sébastien; Pagani, Linda S

2009-06-01

Although the concept of school engagement figures prominently in most school dropout theories, there has been little empirical research conducted on its nature and course and, more importantly, the association with dropout. Information on the natural development of school engagement would greatly benefit those interested in preventing student alienation during adolescence. Using a longitudinal sample of 11,827 French-Canadian high school students, we tested behavioral, affective, cognitive indices of engagement both separately and as a global construct. We then assessed their contribution as prospective predictors of school dropout using factor analysis and structural equation modeling. Global engagement reliably predicted school dropout. Among its three specific dimensions, only behavioral engagement made a significant contribution in the prediction equation. Our findings confirm the robustness of the overall multidimensional construct of school engagement, which reflects both cognitive and psychosocial characteristics, and underscore the importance attributed to basic participation and compliance issues in reliably estimating risk of not completing basic schooling during adolescence.

Development of failure criterion for Kevlar-epoxy fabric laminates

Science.gov (United States)

Tennyson, R. C.; Elliott, W. G.

1984-01-01

The development of the tensor polynomial failure criterion for composite laminate analysis is discussed. In particular, emphasis is given to the fabrication and testing of Kevlar-49 fabric (Style 285)/Narmco 5208 Epoxy. The quadratic-failure criterion with F(12)=0 provides accurate estimates of failure stresses for the Kevlar/Epoxy investigated. The cubic failure criterion was re-cast into an operationally easier form, providing the engineer with design curves that can be applied to laminates fabricated from unidirectional prepregs. In the form presented no interaction strength tests are required, although recourse to the quadratic model and the principal strength parameters is necessary. However, insufficient test data exists at present to generalize this approach for all undirectional prepregs and its use must be restricted to the generic materials investigated to-date.

Assessing stress-related treatment needs among girls at risk for poor functional outcomes: The impact of cumulative adversity, criterion traumas, and non-criterion events.

Science.gov (United States)

Lansing, Amy E; Plante, Wendy Y; Beck, Audrey N

2017-05-01

Despite growing recognition that cumulative adversity (total stressor exposure, including complex trauma), increases the risk for psychopathology and impacts development, assessment strategies lag behind: Adversity-related mental health needs (symptoms, functional impairment, maladaptive coping) are typically assessed in response to only one qualifying Criterion-A traumatic event. This is especially problematic for youth at-risk for health and academic disparities who experience cumulative adversity, including non-qualifying events (separation from caregivers) which may produce more impairing symptomatology. Data from 118 delinquent girls demonstrate: (1) an average of 14 adverse Criterion-A and non-Criterion event exposures; (2) serious maladaptive coping strategies (self-injury) directly in response to cumulative adversity; (3) more cumulative adversity-related than worst-event related symptomatology and functional impairment; and (4) comparable symptomatology, but greater functional impairment, in response to non-Criterion events. These data support the evaluation of mental health needs in response to cumulative adversity for optimal identification and tailoring of services in high-risk populations to reduce disparities. Copyright © 2016 Elsevier Ltd. All rights reserved.

Criterion for the engineering performance of carbon materials under neutron irradiation

International Nuclear Information System (INIS)

Virgil'ev, Yu.S.

2002-01-01

The criterion for the engineering performance and substation of its applicability to the reactor graphite are proposed. The complex indicator, representing the ratio of strength limits by compression and bending is proposed as the above criterion, characterizing the graphite quality. The growth of this criterion indicates the accumulation of large heterogeneities microcracks of technological or radiation character. The decrease in this indicator testifies to the growth of small heterogeneities, and consequently to the increase in the graphite engineering performance [ru

Early Nonresponse in the Antipsychotic Treatment of Acute Mania : A Criterion for Reconsidering Treatment? Results From an Individual Patient Data Meta-Analysis

NARCIS (Netherlands)

Welten, Carlijn C M; Koeter, Maarten W J; Wohlfarth, Tamar D; Storosum, Jitschak G; van den Brink, Wim; Gispen-de Wied, Christine C; Leufkens, Hubert G M; Denys, Damiaan A J P

OBJECTIVE: To investigate whether early nonresponse to antipsychotic treatment of acute mania predicts treatment failure and, if so, to establish the best definition or criterion of an early nonresponse. DATA SOURCES: Short-term efficacy studies assessing antipsychotics that were submitted to the

Entanglement criterion for tripartite systems based on local sum uncertainty relations

Science.gov (United States)

Akbari-Kourbolagh, Y.; Azhdargalam, M.

2018-04-01

We propose a sufficient criterion for the entanglement of tripartite systems based on local sum uncertainty relations for arbitrarily chosen observables of subsystems. This criterion generalizes the tighter criterion for bipartite systems introduced by Zhang et al. [C.-J. Zhang, H. Nha, Y.-S. Zhang, and G.-C. Guo, Phys. Rev. A 81, 012324 (2010), 10.1103/PhysRevA.81.012324] and can be used for both discrete- and continuous-variable systems. It enables us to detect the entanglement of quantum states without having a complete knowledge of them. Its utility is illustrated by some examples of three-qubit, qutrit-qutrit-qubit, and three-mode Gaussian states. It is found that, in comparison with other criteria, this criterion is able to detect some three-qubit bound entangled states more efficiently.

Sensitivity analysis of respiratory parameter uncertainties: impact of criterion function form and constraints.

Science.gov (United States)

Lutchen, K R

1990-08-01

A sensitivity analysis based on weighted least-squares regression is presented to evaluate alternative methods for fitting lumped-parameter models to respiratory impedance data. The goal is to maintain parameter accuracy simultaneously with practical experiment design. The analysis focuses on predicting parameter uncertainties using a linearized approximation for joint confidence regions. Applications are with four-element parallel and viscoelastic models for 0.125- to 4-Hz data and a six-element model with separate tissue and airway properties for input and transfer impedance data from 2-64 Hz. The criterion function form was evaluated by comparing parameter uncertainties when data are fit as magnitude and phase, dynamic resistance and compliance, or real and imaginary parts of input impedance. The proper choice of weighting can make all three criterion variables comparable. For the six-element model, parameter uncertainties were predicted when both input impedance and transfer impedance are acquired and fit simultaneously. A fit to both data sets from 4 to 64 Hz could reduce parameter estimate uncertainties considerably from those achievable by fitting either alone. For the four-element models, use of an independent, but noisy, measure of static compliance was assessed as a constraint on model parameters. This may allow acceptable parameter uncertainties for a minimum frequency of 0.275-0.375 Hz rather than 0.125 Hz. This reduces data acquisition requirements from a 16- to a 5.33- to 8-s breath holding period. These results are approximations, and the impact of using the linearized approximation for the confidence regions is discussed.

Burnout and Engagement: Relative Importance of Predictors and Outcomes in Two Health Care Worker Samples.

Science.gov (United States)

Fragoso, Zachary L; Holcombe, Kyla J; McCluney, Courtney L; Fisher, Gwenith G; McGonagle, Alyssa K; Friebe, Susan J

2016-06-09

This study's purpose was twofold: first, to examine the relative importance of job demands and resources as predictors of burnout and engagement, and second, the relative importance of engagement and burnout related to health, depressive symptoms, work ability, organizational commitment, and turnover intentions in two samples of health care workers. Nurse leaders (n = 162) and licensed emergency medical technicians (EMTs; n = 102) completed surveys. In both samples, job demands predicted burnout more strongly than job resources, and job resources predicted engagement more strongly than job demands. Engagement held more weight than burnout for predicting commitment, and burnout held more weight for predicting health outcomes, depressive symptoms, and work ability. Results have implications for the design, evaluation, and effectiveness of workplace interventions to reduce burnout and improve engagement among health care workers. Actionable recommendations for increasing engagement and decreasing burnout in health care organizations are provided. © 2016 The Author(s).

Mercier criterion for high-β tokamaks

International Nuclear Information System (INIS)

Galvao, R.M.O.

1984-01-01

An expression, for the application of the Mercier criterion to numerical studies of diffuse high-β tokamaks (β approximatelly Σ,q approximatelly 1), which contains only leading order contributions in the high-β tokamak approximation is derived. (L.C.) [pt

Classroom Quality and Student Engagement: Contributions to Third-Grade Reading Skills

Science.gov (United States)

Guo, Ying; Connor, Carol McDonald; Tompkins, Virginia; Morrison, Frederick J.

2011-01-01

This study, using NICHD Study of Early Child Care and Youth Development longitudinal data, investigated the effects of classroom quality and students’ third-grade behavioral engagement on students’ third-grade reading achievement (n = 1,364) and also examined the extent to which students’ third-grade behavioral engagement mediated the association between classroom quality and children's reading skills. SEM results revealed that controlling for family socio economic risk and students’ first-grade reading achievement, classroom quality significantly, and positively predicted children's behavioral engagement, which in turn predicted greater reading achievement. Higher levels of children's behavioral engagement were associated with higher reading achievement. Implications for policy and practice are discussed. PMID:21779272

Study of criterion for assuring the effectiveness of cathodic protection of buried steel pipelines being interfered with alternative current

Energy Technology Data Exchange (ETDEWEB)

He, X.; Jiang, G.; Qiu, Y.; Tang, H. [College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan (China); Zhang, G.; Jin, X.; Xiang, Z. [Huazhong Natural Gas Subsidiary of PetroChina Pipeline Company, Wuhan (China); Zhang, Z. [Dwell Company Limited, PetroChina Engineering Company, Ltd, Beijing (China)

2012-06-15

Interference of alternative current (AC) on corrosion of X65 steel was investigated in soil. It was observed that the unfavorable effect of interfering AC was able to be effectively inhibited by increasing the direct current density of the cathodic protection (CP) system. A clear correlation was established between the CP current density and the tolerable AC current density. This led to a new criterion for assuring the effectiveness of CP of buried pipelines being interfered with AC. Field experimental results on a buried pipeline running below a 500 kV transmission line showed that the criterion could satisfactorily predict the risk of AC interfering on the CP system. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Meaningful work, work engagement and organisational commitment

Directory of Open Access Journals (Sweden)

Madelyn Geldenhuys

2014-03-01

Research purpose: The aim of the study was to investigate the relationships amongst psychological meaningfulness, work engagement and organisational commitment and to test for a possible mediation effect of work engagement on the relationship between psychological meaningfulness and organisational commitment. Motivation for the study: Managers have to rethink ways of improving productivity and performance at work, due to the diverse, and in some instances escalating, needs of employees (e.g. financial support to uphold their interest in and enjoyment of working. Research approach, design and method: A quantitative approach was employed to gather the data for the study, utilising a cross-sectional survey design. The sample (n = 415 consisted of working employees from various companies and positions in Gauteng, South Africa. Main findings: The results confirmed a positive relationship between psychological meaningfulness, work engagement and organisational commitment. Further, psychological meaningfulness predicts work engagement, whilst psychological meaningfulness and work engagement predict organisational commitment. Practical/managerial implications: Employers identifying their employees’ commitment patterns and mapping out strategies for enhancing those that are relevant to organisational goals will yield positive work outcomes (e.g. employees who are creative, seek growth or challenges for themselves. Contribution/value-add: This study contributes to the literature through highlighting the impact that meaningful work has on sustaining employee commitment to the organisation.

Engaging in Work Even When It Is Meaningless: Positive Affective Disposition and Meaningful Work Interact in Relation to Work Engagement

Science.gov (United States)

Steger, Michael F.; Littman-Ovadia, Hadassah; Miller, Michal; Menger, Lauren; Rothmann, Sebastiaan

2013-01-01

The central aim of the present study was to assess the predictive value of affective disposition and meaningful work on employee engagement. Specifically, it was proposed that meaningful work moderates the relationship between affective disposition and engagement. Questionnaires were completed by 252 white-collar employees, working in a variety of…

Study on the quantitative rod internal pressure design criterion

International Nuclear Information System (INIS)

Kim, Kyu Tae; Kim, Oh Hwan; Han, Hee Tak

1991-01-01

The current rod internal pressure criterion permits fuel rods to operate with internal pressures in excess of system pressure only if internal overpressure does not cause the diametral gap enlargement. In this study, the generic allowable internal gas pressure not violating this criterion is estimated as a function of rod power. The results show that the generic allowable internal gas pressure decreases linearly with the increase of rod power. Application of the generic allowable internal gas pressure for the rod internal pressure design criterion will result in the simplication of the current design procedure for checking the diametral gap enlargement caused by internal overpressure because according to the current design procedure the cladding creepout rate should be compared with the fuel swelling rate at each axial node at each time step whenever internal pressure exceeds the system pressure. (Author)

Conflicting views on a neutrality criterion for radioactive-waste management

International Nuclear Information System (INIS)

Cochran, T.B.; Bodde, D.L.

1983-01-01

Two essays are presented by authors who agree that risks imposed on future generations through the management of radioactive waste are acceptable if they meet a criterion of neutrality, but who disagree on the interpretation of the neutrality criterion. The first viewpoint argues that acceptable isolation of high-level radioactive waste is yet to be accomplished and that a fundamental criterion for radioactive waste disposal must include consideration of the intergenerational radiation effects. The second essay promotes balanced resource allocation, technological progress, and adequate problem-solving institutions as the solution to the problem. The debate illustrates the complexities involved in applying philosophical principles to public policy, even when the principles have been agreed upon. 23 references, 1 figure

Elitism, Sharing and Ranking Choices in Evolutionary Multi-Criterion Optimisation

OpenAIRE

Pursehouse, R.C.; Fleming, P.J.

2002-01-01

Elitism and sharing are two mechanisms that are believed to improve the performance of an evolutionary multi-criterion optimiser. The relative performance of of the two most popular ranking strategies is largely unknown. Using a new empirical inquiry framework, this report studies the effect of elitism, sharing and ranking design choices using a benchmark suite of two-criterion problems.........

Validation of a Criterion for Cam Mechanisms Optimization Using Constraints upon Cam’s Curvature

Directory of Open Access Journals (Sweden)

Stelian Alaci

2016-06-01

Full Text Available For the mechanism with rotating cam and knife-edge follower, an optimization criterion by means of imposed constraints upon cam’s curvature is expressed in a special coordinate system. Thus, stating the optimization criterion in the coordinate system defined by the mechanisms constructive parameters -eccentricity and minimum follower’s stroke, a contour is obtained for any position of the mechanism. The optimization criterion assumes establishing the position of the characteristic point of the mechanism with respect to this contour. Fulfillment of optimization criterion assumes that the characteristic point is positioned in the same manner with respect to all contours. The optimization criterion is simplified when considering the envelope of the contours. The method is exemplified using two mechanisms, with the cams priori satisfying the criterion.

[On the problems of the evolutionary optimization of life history. II. To justification of optimization criterion for nonlinear Leslie model].

Science.gov (United States)

Pasekov, V P

2013-03-01

The paper considers the problems in the adaptive evolution of life-history traits for individuals in the nonlinear Leslie model of age-structured population. The possibility to predict adaptation results as the values of organism's traits (properties) that provide for the maximum of a certain function of traits (optimization criterion) is studied. An ideal criterion of this type is Darwinian fitness as a characteristic of success of an individual's life history. Criticism of the optimization approach is associated with the fact that it does not take into account the changes in the environmental conditions (in a broad sense) caused by evolution, thereby leading to losses in the adequacy of the criterion. In addition, the justification for this criterion under stationary conditions is not usually rigorous. It has been suggested to overcome these objections in terms of the adaptive dynamics theory using the concept of invasive fitness. The reasons are given that favor the application of the average number of offspring for an individual, R(L), as an optimization criterion in the nonlinear Leslie model. According to the theory of quantitative genetics, the selection for fertility (that is, for a set of correlated quantitative traits determined by both multiple loci and the environment) leads to an increase in R(L). In terms of adaptive dynamics, the maximum R(L) corresponds to the evolutionary stability and, in certain cases, convergent stability of the values for traits. The search for evolutionarily stable values on the background of limited resources for reproduction is a problem of linear programming.

Class Anxiety in Secondary Education: Exploring Structural Relations with Perceived Control, Engagement, Disaffection, and Performance.

Science.gov (United States)

González, Antonio; Faílde Garrido, José María; Rodríguez Castro, Yolanda; Carrera Rodríguez, María Victoria

2015-09-14

The aim of this study was to assess the relationships between class-related anxiety with perceived control, teacher-reported behavioral engagement, behavioral disaffection, and academic performance. Participants were 355 compulsory secondary students (9th and 10th grades; Mean age = 15.2 years; SD = 1.8 years). Structural equation models revealed performance was predicted by perceived control, anxiety, disaffection, and engagement. Perceived control predicted anxiety, disaffection, and engagement. Anxiety predicted disaffection and engagement, and partially mediated the effects from control on disaffection (β = -.277, p anxiety and performance was mediated by engagement and disaffection (β = -.295, p Anxiety, engagement, and disaffection mediated the effects of control on performance (β = .352, p < .003; CI = .279, .440). The implications of these results are discussed in the light of current theory and educational interventions.

A Fisher’s Criterion-Based Linear Discriminant Analysis for Predicting the Critical Values of Coal and Gas Outbursts Using the Initial Gas Flow in a Borehole

Directory of Open Access Journals (Sweden)

Xiaowei Li

2017-01-01

Full Text Available The risk of coal and gas outbursts can be predicted using a method that is linear and continuous and based on the initial gas flow in the borehole (IGFB; this method is significantly superior to the traditional point prediction method. Acquiring accurate critical values is the key to ensuring accurate predictions. Based on ideal rock cross-cut coal uncovering model, the IGFB measurement device was developed. The present study measured the data of the initial gas flow over 3 min in a 1 m long borehole with a diameter of 42 mm in the laboratory. A total of 48 sets of data were obtained. These data were fuzzy and chaotic. Fisher’s discrimination method was able to transform these spatial data, which were multidimensional due to the factors influencing the IGFB, into a one-dimensional function and determine its critical value. Then, by processing the data into a normal distribution, the critical values of the outbursts were analyzed using linear discriminant analysis with Fisher’s criterion. The weak and strong outbursts had critical values of 36.63 L and 80.85 L, respectively, and the accuracy of the back-discriminant analysis for the weak and strong outbursts was 94.74% and 92.86%, respectively. Eight outburst tests were simulated in the laboratory, the reverse verification accuracy was 100%, and the accuracy of the critical value was verified.

Profiles of recovery from mood and anxiety disorders: A person-centered exploration of people’s engagement in self-management

Directory of Open Access Journals (Sweden)

Simon eCoulombe

2016-04-01

Full Text Available Context: A shift towards person-centered care has been occurring in services provided to people with mood and anxiety disorders. Recovery is recognized as encompassing personal aspects in addition to clinical ones. Guidelines now recommend supporting people’s engagement in self-management as a complementary recovery avenue. Yet the literature lacks evidence on how individualized combinations of self-management strategies used by people relate to their clinical and personal recovery indicators. Objectives: The aim of this study was to identify profiles underlying mental health recovery, describe the characteristics of participants corresponding to each profile, and examine the associations of profiles with criterion variables. Method: 149 people recovering from anxiety, depressive, or bipolar disorders completed questionnaires on self-management, clinical recovery (symptom severity, personal recovery (positive mental health, and criterion variables (personal goal appraisal, social participation, self-care abilities, coping. Results: Latent profile analysis revealed three profiles. The Floundering profile included participants who rarely used self-management strategies and had moderately severe symptoms and the lowest positive mental health. The Flourishing profile was characterized by frequent use of self-empowerment strategies, the least severe symptoms, and the highest positive mental health. Participants in the Struggling profile engaged actively in several self-management strategies focused on symptom reduction and healthy lifestyle. They concomitantly reported high symptom severity and moderately high positive mental health. The study revealed that Floundering was associated with higher probabilities of being a man, being single, and having a low income. People in the Flourishing profile had the most favorable scores on criterion variables, supporting the profiles’ construct validity. Discussion: The mixed portrait of Struggling

Motivational engagement in first-time hearing aid users: A feasibility study.

Science.gov (United States)

Ferguson, Melanie; Maidment, David; Russell, Naomi; Gregory, Melanie; Nicholson, Richard

2016-07-01

To assess (1) the feasibility of incorporating the Ida Institute's Motivation Tools into a UK audiology service, (2) the potential benefits of motivational engagement in first-time hearing aid users, and (3) predictors of hearing aid and general health outcome measures. A feasibility study using a single-centre, prospective, quasi-randomized controlled design with two arms. The Ida Institute's Motivation Tools formed the basis for motivational engagement. First-time hearing aid users were recruited at the initial hearing assessment appointment. The intervention arm underwent motivational engagement (M+, n = 32), and a control arm (M-, n = 36) received standard care only. The M+ group showed greater self-efficacy, reduced anxiety, and greater engagement with the audiologist at assessment and fitting appointments. However, there were no significant between-group differences 10-weeks post-fitting. Hearing-related communication scores predicted anxiety, and social isolation scores predicted depression for the M+ group. Readiness to address hearing difficulties predicted hearing aid outcomes for the M- group. Hearing sensitivity was not a predictor of outcomes. There were some positive results from motivational engagement early in the patient journey. Future research should consider using qualitative methods to explore whether there are longer-term benefits of motivational engagement in hearing aid users.

What makes a life event traumatic for a child? The predictive values of DSM-Criteria A1 and A2

Directory of Open Access Journals (Sweden)

Eva Verlinden

2013-08-01

Full Text Available Background: The Diagnostic and Statistical Manual of Mental Disorders (DSM-Criteria A1 and A2 for posttraumatic stress disorder (PTSD have been discussed extensively, with several studies in adults or adolescents supporting the removal of Criterion A2. However, solid research in children is missing. Objective: This study evaluated the DSM-Criteria A1 and A2 in predicting posttraumatic stress in children. Method: A sample of 588 Dutch school children, aged 8–18 years, completed a self-report questionnaire to determine if they met Criteria A1 and/or A2. Their posttraumatic stress response was assessed using the Children's Revised Impact of Event Scale. Results: The contribution of Criterion A2 to the prediction of posttraumatic stress in children is of greater importance than the contribution of Criterion A1. Children who met Criterion A2 reported significantly higher levels of posttraumatic stress and were nine times more likely to develop probable PTSD than children who did not meet Criterion A2. When Criterion A1 was met, a child was only two times more likely to develop probable PTSD as compared with those where Criterion A1 was not met. Furthermore, the low sensitivity of Criterion A1 suggests that children may regularly develop severe posttraumatic stress in the absence of Criterion A1. The remarkably high negative predictive value of Criterion A2 indicates that if a child does not have a subjective reaction during an event that it is unlikely that he or she will develop PTSD. Conclusions: In contrast to most adult studies, the findings of this study emphasize the significant contribution of Criterion A2 to the prediction of posttraumatic stress in children and raise fundamental questions about the value of the current Criterion A1.For the abstract or full text in other languages, please seeSupplementary files under Article Tools online

Application of the MIT two-channel model to predict flow recirculation in WARD 61-pin blanket tests

International Nuclear Information System (INIS)

Huang, T.T.; Todreas, N.E.

1983-01-01

The preliminary application of MIT two-channel model to WARD sodium blanket tests was presented in this report. The criterion was employed to predict the recirculation for selected completed (transient and steady state) and proposed (transient only) tests. The heat loss was correlated from the results of the WARD zero power tests. The calculational results show that the criterion agrees with the WARD tests except for WARD RUN 718 for which the criterion predicts a different result from WARD data under bundle heat loss condition. However, if the test assembly is adiabatic, the calculations predict an operating point which is marginally close to the mixed-to-recirculation transition regime

Application of the MIT two-channel model to predict flow recirculation in WARD 61-pin blanket tests

International Nuclear Information System (INIS)

Huang, T.T.; Todreas, N.E.

1983-01-01

The preliminary application of MIT TWO-CHANNEL MODEL to WARD sodium blanket tests was presented in this report. Our criterion was employed to predict the recirculation for selected completed (transient and steady state) and proposed (transient only) tests. The heat loss was correlated from the results of the WARD zero power tests. The calculational results show that our criterion agrees with the WARD tests except for WARD RUN 718 for which the criterion predicts a different result from WARD data under bundle heat loss condition. However, if the test assembly is adiabatic, the calculations predict an operating point which is marginally close to the mixed-to-recirculation transition regime

Knowledge processing and faculty engagement in multicultural university settings

DEFF Research Database (Denmark)

Selmer, Jan; Jonasson, Charlotte; Lauring, Jakob

2014-01-01

In educational studies much attention has been directed to engagement as a precondition for positive student outcomes. Very few studies, however, have focused on the engagement of the faculty members. This is a regrettable omission because engagement has been argued to lead to more satisfied, more...... – and faculty engagement. Our hypotheses are based on social learning theory and social exchange theory predicting that increased knowledge sharing activities could facilitate an environment in which faculty engagement thrives. In order to test our hypotheses we use multiple regression analysis. We assessed...... indicators of behavioural, cognitive and emotional engagement. Results showed consistent positive associations between group knowledge processing and all the studied faculty engagement indicators. Implications and suggestions for future research are discussed in detail....

Relationships between the coach-created motivational climate and athlete engagement in youth sport.

Science.gov (United States)

Curran, Thomas; Hill, Andrew P; Hall, Howard K; Jowett, Gareth E

2015-04-01

Youth sport is a source of well-being for adolescents, yet experiences vary and attrition can be high. We sought to better understand the coach behaviors that foster positive experiences in youth sport by examining relationships between the motivational climate and athlete engagement (viz., confidence, dedication, enthusiasm, and vigor). We reasoned that a mastery climate (emphasis on effort and learning) would correspond with higher engagement, whereas a performance climate (emphasis on ability and outcome) was expected to correspond with lower engagement. Two-hundred sixty adolescent soccer players completed measures of engagement and perceived coach motivational climate. All dimensions of engagement were positively predicted by a mastery climate. Furthermore, cognitive aspects of engagement were positively predicted by a performance climate. Canonical correlation analysis indicated that a composite of engagement was positively associated with a mastery climate. Results suggest that a mastery climate offers a means of promoting higher levels of overall engagement.

Judging Criterion of Controlled Structures with Closely Spaced Natural Frequencies

International Nuclear Information System (INIS)

Xie Faxiang; Sun Limin

2010-01-01

The structures with closely spaced natural frequencies widely exist in civil engineering; however, the judging criterion of the density of closely spaced frequencies is in dispute. This paper suggests a judging criterion for structures with closely spaced natural frequencies based on the analysis on a controlled 2-DOF structure. The analysis results indicate that the optimal control gain of the structure with velocity feedback is dependent on the frequency density parameter of structure and the maximum attainable additional modal damping ratio is 1.72 times of the frequency density parameter when state feedback is applied. Based on a brief review on the previous researches, a judging criterion related the minimum frequency density parameter and the required mode damping ratio was proposed.

Social capital among healthcare professionals: A prospective study of its importance for job satisfaction, work engagement and engagement in clinical improvements.

Science.gov (United States)

Strömgren, Marcus; Eriksson, Andrea; Bergman, David; Dellve, Lotta

2016-01-01

Social capital can be an important resource to facilitate the needed improvements in quality of care and efficiency in hospitals. To assess the importance of social capital (recognition, vertical trust, horizontal trust and reciprocity) for job satisfaction, work engagement and engagement in clinical improvements. A prospective cohort design was used. Intensive care units and emergency, surgical and medical units at five Swedish hospitals with ongoing development of their processes of care. Healthcare professionals (physicians, registered nurses, assistant nurses) at five Swedish midsize hospitals. The participants answered a questionnaire at two occasions, NN=1602 at baseline and NN=1548 at one-year follow-up. Mean hospital response rate was 53% at baseline and 59% at follow-up. Univariate, multivariate and logistic regression analyses were performed, and the prospective analysis was based on 477 respondents. Social capital was associated with healthcare professionals' general work engagement and job satisfaction. Analysis showed positive associations between all measured aspects of social capital and engagement in clinical improvements of patient safety and quality of care. The prospective analysis showed that increased social capital predicted increased job satisfaction, work engagement and engagement in clinical improvements of patient safety. Social capital is strongly related to job satisfaction and active engagement with clinical improvements. The findings contribute to a deeper knowledge of social capital as a predictive factor that influences patient safety and health among healthcare staff. Copyright © 2015 Elsevier Ltd. All rights reserved.

Geoscience Education and Public Outreach AND CRITERION 2: MAKING A BROADER IMPACT

Science.gov (United States)

Marlino, M.; Scotchmoor, J. G.

2005-12-01

The geosciences influence our daily lives and yet often go unnoticed by the general public. From the moment we listen to the weather report and fill-up our cars for the daily commute, until we return to our homes constructed from natural resources, we rely on years of scientific research. The challenge facing the geosciences is to make explicit to the public not only the criticality of the research whose benefits they enjoy, but also to actively engage them as partners in the research effort, by providing them with sufficient understanding of the scientific enterprise so that they become thoughtful and proactive when making decisions in the polling booth. Today, there is broad recognition within the science and policy community that communication needs to be more effective, more visible, and that the public communication of the scientific enterprise is critical not only to its taxpayer support, but also to maintenance of a skilled workforce and the standard of living expected by many Americans. In 1997, the National Science Board took the first critical step in creating a cultural change in the scientific community by requiring explicit consideration of the broader impacts of research in every research proposal. The so-called Criterion 2 has catalyzed a dramatic shift in expectations within the geoscience community and an incentive for finding ways to encourage the science research community to select education and public outreach as a venue for responding to Criterion 2. In response, a workshop organized by the University of California Museum of Paleontology and the Digital Library for Earth System Education (DLESE) was held on the Berkeley campus May 11-13, 2005. The Geoscience EPO Workshop purposefully narrowed its focus to that of education and public outreach. This workshop was based on the premise that there are proven models and best practices for effective outreach strategies that need to be identified and shared with research scientists. Workshop

Towards understanding causality between work engagement and psychological capital

Directory of Open Access Journals (Sweden)

Johannes J. de Waal

2013-10-01

Research purpose: The main aim of this study was to conceptualise and investigate the causal relationship and temporal order in the relationship between PsyCap and engagement by means of longitudinal data. Motivation for the study: The rationale for establishing the sequence of engagement and psychological capital lies in the fact that training interventions to enhance the organisational well-being of employees may need to be focused on either one or the other. Research design, approach and method: A longitudinal study with a cross-lagged panel design was conducted; data was gathered by means of a survey that was constructed for the purpose of the study. The survey contained the Utrecht Work Engagement Scale (UWES, and a measure of PsyCap. All employees within a chemical factory (N = 1003 were approached to provide data; 163 employees participated. Main findings: Results revealed that PsyCap at Time 1 (T1 did not significantly predict engagement at Time 2 (T2. Evidence does however exist that initial levels of employee engagement predict subsequent PsyCap. Practical/managerial implications: Results suggest that employee interventions aimed at protecting and fostering employee engagement may have implications for subsequent employee psychological capital. Contribution/value-add: As an empirical, longitudinal study to address the temporal order between PsyCap and work engagement, this study makes a contribution especially to theory, but also with practical implications by indicating that engagement precedes employee psychological capital.

General Criterion for Harmonicity

Science.gov (United States)

Proesmans, Karel; Vandebroek, Hans; Van den Broeck, Christian

2017-10-01

Inspired by Kubo-Anderson Markov processes, we introduce a new class of transfer matrices whose largest eigenvalue is determined by a simple explicit algebraic equation. Applications include the free energy calculation for various equilibrium systems and a general criterion for perfect harmonicity, i.e., a free energy that is exactly quadratic in the external field. As an illustration, we construct a "perfect spring," namely, a polymer with non-Gaussian, exponentially distributed subunits which, nevertheless, remains harmonic until it is fully stretched. This surprising discovery is confirmed by Monte Carlo and Langevin simulations.

Modeling a failure criterion for U-Mo/Al dispersion fuel

Science.gov (United States)

Oh, Jae-Yong; Kim, Yeon Soo; Tahk, Young-Wook; Kim, Hyun-Jung; Kong, Eui-Hyun; Yim, Jeong-Sik

2016-05-01

The breakaway swelling in U-Mo/Al dispersion fuel is known to be caused by large pore formation enhanced by interaction layer (IL) growth between fuel particles and Al matrix. In this study, a critical IL thickness was defined as a criterion for the formation of a large pore in U-Mo/Al dispersion fuel. Specifically, the critical IL thickness is given when two neighboring fuel particles come into contact with each other in the developed IL. The model was verified using the irradiation data from the RERTR tests and KOMO-4 test. The model application to full-sized sample irradiations such as IRISs, FUTURE, E-FUTURE, and AFIP-1 tests resulted in conservative predictions. The parametric study revealed that the fuel particle size and the homogeneity of the fuel particle distribution are influential for fuel performance.

Modeling a failure criterion for U–Mo/Al dispersion fuel

Energy Technology Data Exchange (ETDEWEB)

Oh, Jae-Yong, E-mail: tylor@kaeri.re.kr [Korea Atomic Energy Research Institute, 111, Daedeok-Daero 989 Beon-Gil, Yuseong-Gu, Daejeon 305-353 (Korea, Republic of); Kim, Yeon Soo [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Tahk, Young-Wook; Kim, Hyun-Jung; Kong, Eui-Hyun; Yim, Jeong-Sik [Korea Atomic Energy Research Institute, 111, Daedeok-Daero 989 Beon-Gil, Yuseong-Gu, Daejeon 305-353 (Korea, Republic of)

2016-05-15

The breakaway swelling in U–Mo/Al dispersion fuel is known to be caused by large pore formation enhanced by interaction layer (IL) growth between fuel particles and Al matrix. In this study, a critical IL thickness was defined as a criterion for the formation of a large pore in U–Mo/Al dispersion fuel. Specifically, the critical IL thickness is given when two neighboring fuel particles come into contact with each other in the developed IL. The model was verified using the irradiation data from the RERTR tests and KOMO-4 test. The model application to full-sized sample irradiations such as IRISs, FUTURE, E-FUTURE, and AFIP-1 tests resulted in conservative predictions. The parametric study revealed that the fuel particle size and the homogeneity of the fuel particle distribution are influential for fuel performance.

Stochastic Learning and the Intuitive Criterion in Simple Signaling Games

DEFF Research Database (Denmark)

Sloth, Birgitte; Whitta-Jacobsen, Hans Jørgen

A stochastic learning process for signaling games with two types, two signals, and two responses gives rise to equilibrium selection which is in remarkable accordance with the selection obtained by the intuitive criterion......A stochastic learning process for signaling games with two types, two signals, and two responses gives rise to equilibrium selection which is in remarkable accordance with the selection obtained by the intuitive criterion...

An assessment of the overlap between morale and work engagement in a nonoperational military sample.

Science.gov (United States)

Ivey, Gary W; Blanc, J-R Sébastien; Mantler, Janet

2015-07-01

The degree of overlap between two positive motivational constructs-morale and work engagement-was assessed in a random sample of Canadian Armed Forces personnel stationed across Canada (N = 1,224). Based on self-determination theory and past research, job-specific self-efficacy, trust in teammates, and job significance were expected to be associated with morale and work engagement. Structural equation modeling analyses revealed that morale and work engagement were highly positively correlated, but had different patterns of association with predictor and outcome variables. Although trust in teammates and job significance predicted both morale and work engagement, job-specific self-efficacy predicted morale but not work engagement. Willingness to deploy on operations, turnover intentions, and psychological distress were predicted by both morale and work engagement, but morale was a better predictor of psychological distress and work engagement was a stronger predictor of turnover intentions. Together, the results suggest that, despite their overlap, morale and work engagement, as defined and measured herein, are not interchangeable. (c) 2015 APA, all rights reserved).

Selecting Items for Criterion-Referenced Tests.

Science.gov (United States)

Mellenbergh, Gideon J.; van der Linden, Wim J.

1982-01-01

Three item selection methods for criterion-referenced tests are examined: the classical theory of item difficulty and item-test correlation; the latent trait theory of item characteristic curves; and a decision-theoretic approach for optimal item selection. Item contribution to the standardized expected utility of mastery testing is discussed. (CM)

How Transformational Leadership Influences Work Engagement Among Nurses: Does Person-Job Fit Matter?

Science.gov (United States)

Enwereuzor, Ibeawuchi K; Ugwu, Leonard I; Eze, Onyinyechi A

2018-03-01

The current study examines whether person-job fit moderates the relationship between transformational leadership and work engagement. Data were collected using cross-sectional design from 224 (15 male and 209 female) hospital nurses. Participants completed measures of transformational leadership, person-job fit, and work engagement. Moderated multiple regression results showed that transformational leadership had a significant positive predictive relationship with work engagement, and person-job fit had a significant positive predictive relationship with work engagement. Simple slope analysis showed that person-job fit moderated the relationship between transformational leadership and work engagement such that transformational leadership was more positively related to work engagement for nurses with high person-job fit compared with those with low person-job fit. Thus, all the hypotheses were confirmed. The findings were discussed, and suggestions for future research were offered.

Multiaxial fatigue criterion based on parameters from torsion and axial S-N curve

Directory of Open Access Journals (Sweden)

M. Margetin

2016-07-01

Full Text Available Multiaxial high cycle fatigue is a topic that concerns nearly all industrial domains. In recent years, a great deal of recommendations how to address problems with multiaxial fatigue life time estimation have been made and a huge progress in the field has been achieved. Until now, however, no universal criterion for multiaxial fatigue has been proposed. Addressing this situation, this paper offers a design of a new multiaxial criterion for high cycle fatigue. This criterion is based on critical plane search. Damage parameter consists of a combination of normal and shear stresses on a critical plane (which is a plane with maximal shear stress amplitude. Material parameters used in proposed criterion are obtained from torsion and axial S-N curves. Proposed criterion correctly calculates life time for boundary loading condition (pure torsion and pure axial loading. Application of proposed model is demonstrated on biaxial loading and the results are verified with testing program using specimens made from S355 steel. Fatigue material parameters for proposed criterion and multiple sets of data for different combination of axial and torsional loading have been obtained during the experiment.

Predictability of Seasonal Rainfall over the Greater Horn of Africa

Science.gov (United States)

Ngaina, J. N.

2016-12-01

The El Nino-Southern Oscillation (ENSO) is a primary mode of climate variability in the Greater of Africa (GHA). The expected impacts of climate variability and change on water, agriculture, and food resources in GHA underscore the importance of reliable and accurate seasonal climate predictions. The study evaluated different model selection criteria which included the Coefficient of determination (R2), Akaike's Information Criterion (AIC), Bayesian Information Criterion (BIC), and the Fisher information approximation (FIA). A forecast scheme based on the optimal model was developed to predict the October-November-December (OND) and March-April-May (MAM) rainfall. The predictability of GHA rainfall based on ENSO was quantified based on composite analysis, correlations and contingency tables. A test for field-significance considering the properties of finiteness and interdependence of the spatial grid was applied to avoid correlations by chance. The study identified FIA as the optimal model selection criterion. However, complex model selection criteria (FIA followed by BIC) performed better compared to simple approach (R2 and AIC). Notably, operational seasonal rainfall predictions over the GHA makes of simple model selection procedures e.g. R2. Rainfall is modestly predictable based on ENSO during OND and MAM seasons. El Nino typically leads to wetter conditions during OND and drier conditions during MAM. The correlations of ENSO indices with rainfall are statistically significant for OND and MAM seasons. Analysis based on contingency tables shows higher predictability of OND rainfall with the use of ENSO indices derived from the Pacific and Indian Oceans sea surfaces showing significant improvement during OND season. The predictability based on ENSO for OND rainfall is robust on a decadal scale compared to MAM. An ENSO-based scheme based on an optimal model selection criterion can thus provide skillful rainfall predictions over GHA. This study concludes that the

The role of word choice and criterion on intentional memory.

Science.gov (United States)

Toyota, Hiroshi

2015-02-01

The relationship between the criterion for choosing and the self-choice effects (greater recall in a self-choice compared to a forced-choice condition) on intentional memory was examined. Thirty-three female nursing school volunteers were administered 24 word pairs in a 2 × 2 design to assess the influence of motivation upon free recall. When word pairs were presented to participants, they were asked to choose a word to-be-remembered, either in a self-choice condition or a forced-choice condition. Words chosen by the participants were recalled more often than those chosen by the experimenter (forced choice). Thus, the self-choice effect was greater for words chosen with a self-reference criterion compared to a metamemory criterion, supporting the integration hypothesis as the origin of the self-choice effect.

Surrogate screening models for the low physical activity criterion of frailty.

Science.gov (United States)

Eckel, Sandrah P; Bandeen-Roche, Karen; Chaves, Paulo H M; Fried, Linda P; Louis, Thomas A

2011-06-01

Low physical activity, one of five criteria in a validated clinical phenotype of frailty, is assessed by a standardized, semiquantitative questionnaire on up to 20 leisure time activities. Because of the time demanded to collect the interview data, it has been challenging to translate to studies other than the Cardiovascular Health Study (CHS), for which it was developed. Considering subsets of activities, we identified and evaluated streamlined surrogate assessment methods and compared them to one implemented in the Women's Health and Aging Study (WHAS). Using data on men and women ages 65 and older from the CHS, we applied logistic regression models to rank activities by "relative influence" in predicting low physical activity.We considered subsets of the most influential activities as inputs to potential surrogate models (logistic regressions). We evaluated predictive accuracy and predictive validity using the area under receiver operating characteristic curves and assessed criterion validity using proportional hazards models relating frailty status (defined using the surrogate) to mortality. Walking for exercise and moderately strenuous household chores were highly influential for both genders. Women required fewer activities than men for accurate classification. The WHAS model (8 CHS activities) was an effective surrogate, but a surrogate using 6 activities (walking, chores, gardening, general exercise, mowing and golfing) was also highly predictive. We recommend a 6 activity questionnaire to assess physical activity for men and women. If efficiency is essential and the study involves only women, fewer activities can be included.

Student Engagement and Classroom Variables in Improving Mathematics Achievement

Science.gov (United States)

Park, So-Young

2005-01-01

The study explored how much student engagement and classroom variables predicted student achievement in mathematics. Since students were nested within a classroom, hierarchical linear modeling (HLM) was employed for the analysis. The results indicated that student engagement had positive effects on student academic growth per month in math after…

ON THE VALIDITY OF THE 'HILL RADIUS CRITERION' FOR THE EJECTION OF PLANETS FROM STELLAR HABITABLE ZONES

International Nuclear Information System (INIS)

Cuntz, M.; Yeager, K. E.

2009-01-01

We challenge the customary assumption that the entering of an Earth-mass planet into the Hill radius (or multiples of the Hill radius) of a giant planet is a valid criterion for its ejection from the star-planet system. This assumption has widely been used in previous studies, especially those with an astrobiological focus. As intriguing examples, we explore the dynamics of the systems HD 20782 and HD 188015. Each system possesses a giant planet that remains in or crosses into the stellar habitable zone, thus effectively thwarting the possibility of habitable terrestrial planets. In the case of HD 188015, the orbit of the giant planet is almost circular, whereas in the case of HD 20782, it is extremely elliptical. Although it is found that Earth-mass planets are eventually ejected from the habitable zones of these systems, the 'Hill Radius Criterion' is identified as invalid for the prediction of when the ejection is actually occurring.

Development of Predictor and Criterion Measures for the NCO21 Research Program

National Research Council Canada - National Science Library

Knapp, Deidre

2002-01-01

... incorporated into an NCO performance management system geared to 21st century job demands. This report documents the design and development of predictor and criterion measures that will be used in a criterion-related validation data collection...

Study of failure criterion applicable to elastic-plastic finite element analyses of wall-thinned pipes subjected to multi-axial loading. Case for groove type flaw under combined internal pressure and bending loading

International Nuclear Information System (INIS)

Mori, Kosuke; Meshii, Toshiyuki

2015-01-01

In this paper, a failure criterion applicable to large-strain finite element analysis (FEA) results was studied to predict the limit bending load M_c of the groove shaped wall-thinned pipes, under combined internal pressure and bending load, that experienced cracking. In our previous studies, Meshii and Ito (2012) considered cracking of pipes with groove shaped flaw (small axial length δ_z in Fig. 1) was due to the plastic instability at the wall-thinned section and proposed the Domain Collapse Criterion (DCC). The DCC could predict M_c of cracking for small δ_z by comparing the von Mises stress σ_M_i_s_e_s with the true tensile strength σ_B. Because the discrepancy in prediction of the M_c in the case of cracking was within 15%, it was considered that the predictability was could be improved further. Thus, in this work, attempt was made to improve the accuracy of M_c prediction with a perspective that multi-axial stress state might affect this plastic instability at the wall-thinned section. As a result of examination of the various failure criteria based on multi-axial stress, it was confirmed that the limit bending load of the groove flawed pipe that experienced cracking in experiment (Hereafter, it was expressed 'flawed pipe that experienced cracking') could be predicted within 5% accuracy by applying Hill's plastic instability onset criterion (Hill, 1952) to the outer surface of the crack penetration section. The accuracy of the predicted limit bending load was improved from DCC's within 15% to within 5%. (author)

A Controlled Evaluation of the Distress Criterion for Binge Eating Disorder

Science.gov (United States)

Grilo, Carlos M.; White, Marney A.

2011-01-01

Objective: Research has examined various aspects of the validity of the research criteria for binge eating disorder (BED) but has yet to evaluate the utility of Criterion C, "marked distress about binge eating." This study examined the significance of the marked distress criterion for BED using 2 complementary comparison groups. Method:…

Effects of Mastery Criterion on the Emergence of Derived Equivalence Relations

Science.gov (United States)

Fienup, Daniel M.; Brodsky, Julia

2017-01-01

In this study, we manipulated mastery criterion form (rolling or block) and stringency (across 6 or 12 trials) and measured the emergence of derived relations. College students learned neuroanatomy equivalence classes and experienced one of two rolling mastery criteria (6 or 12 consecutive correct responses) or a block mastery criterion (12 trials…

The prospective usefulness of callous-unemotional traits and conduct disorder in predicting treatment engagement among detained girls.

Science.gov (United States)

Colins, Olivier F; Van Damme, Lore; Fanti, Kostas A; Andershed, Henrik

2017-01-01

Although treatment engagement (TE) is crucial for treatment success it is not well known how likely detained girls are to engage in treatment and what features may impede them from doing so. This study is the first to examine the prognostic usefulness of two features of potential interest, being callous-unemotional (CU) traits and conduct disorder (CD), in relation to TE. Detained girls and their parents (n = 75) were interviewed with the Diagnostic Interview Schedule for Children to assess CD, and completed the Antisocial Process Screening Device to assess CU traits dimensionally and categorically as in the new diagnostic and statistical manual of mental disorders, fifth edition (DSM-5) CU-based specifier. One to two months later, the girls reported how much they engaged in treatment. At the zero-order level, self-, but not parent-reported CU traits and CD were predictive of lower levels of TE. The incorporation of CU traits into a diagnosis of CD identified girls with lower levels of future TE, a finding that held across different informants. Of note, the aforementioned findings only became apparent when using a dimensional measure of CU traits, and not when using the categorical measure of CU traits currently included in DSM-5. This study showed that CU traits can help developing an understanding of what factors hinder TE among detained girls. Our findings also support recommendations to incorporate CU traits into the CD diagnosis, and suggest that dimensional approaches to do so may yield relevant information about future levels of TE.

Volitional Trust, Autonomy Satisfaction, and Engagement at Work.

Science.gov (United States)

Heyns, Marita; Rothmann, Sebastiaan

2018-02-01

This study tested a structural model that identifies the nature of relationships between trust, autonomy satisfaction, and personal engagement at work. A cross-sectional survey design with a convenience sample ( n = 252) was used. The Behavioral Trust Inventory, Work-Related Basic Need Satisfaction Scale, and Work Engagement Scale were administered. While reliance-based trust did not have a significant influence on engagement, disclosure-based trust in a focal leader was found to predict satisfaction of autonomy needs and employee engagement. Mediation analyses revealed that satisfaction of the need for autonomy facilitates the influence of trust on work outcomes. More specifically, disclosure (a dimension of trust) impacted engagement via autonomy satisfaction. Overall, the model explained 44% of total variance in engagement, to which the variables proportionately contributed as follows: autonomy satisfaction = 79.58%, disclosure = 18.22%, and reliance = 2.20%. The findings provide possible directions for how leaders can leverage trust to facilitate autonomy support and higher levels of engagement.

Fulfillment of the kinetic Bohm criterion in a quasineutral particle-in-cell model

International Nuclear Information System (INIS)

Ahedo, Eduardo; Santos, Robert; Parra, Felix I.

2010-01-01

Quasineutral particle-in-cell models of ions must fulfill the kinetic Bohm criterion, in its inequality form, at the domain boundary in order to match correctly with solutions of the Debye sheaths tied to the walls. The simple, fluid form of the Bohm criterion is shown to be a bad approximation of the exact, kinetic form when the ion velocity distribution function has a significant dispersion and involves different charge numbers. The fulfillment of the Bohm criterion is measured by a weighting algorithm at the boundary, but linear weighting algorithms have difficulties to reproduce the nonlinear behavior around the sheath edge. A surface weighting algorithm with an extended temporal weighting is proposed and shown to behave better than the standard volumetric weighting. Still, this must be supplemented by a forcing algorithm of the kinetic Bohm criterion. This postulates a small potential fall in a supplementary, thin, transition layer. The electron-wall interaction is shown to be of little relevance in the fulfillment of the Bohm criterion.

Understanding motivational structures that differentially predict engagement and achievement in middle school science

Science.gov (United States)

Lee, Christine S.; Hayes, Kathryn N.; Seitz, Jeffery; DiStefano, Rachelle; O'Connor, Dawn

2016-01-01

Middle school has been documented as the period in which a drop in students' science interest and achievement occurs. This trend indicates a lack of motivation for learning science; however, little is known about how different aspects of motivation interact with student engagement and science learning outcomes. This study examines the relationships among motivational factors, engagement, and achievement in middle school science (grades 6-8). Data were obtained from middle school students in the United States (N = 2094). The theoretical relationships among motivational constructs, including self-efficacy, and three types of goal orientations (mastery, performance approach, and performance avoid) were tested. The results showed that motivation is best modeled as distinct intrinsic and extrinsic factors; lending evidence that external, performance based goal orientations factor separately from self-efficacy and an internal, mastery based goal orientation. Second, a model was tested to examine how engagement mediated the relationships between intrinsic and extrinsic motivational factors and science achievement. Engagement mediated the relationship between intrinsic motivation and science achievement, whereas extrinsic motivation had no relationship with engagement and science achievement. Implications for how classroom practice and educational policy emphasize different student motivations, and in turn, can support or hinder students' science learning are discussed.

Slope stability analysis using limit equilibrium method in nonlinear criterion.

Science.gov (United States)

Lin, Hang; Zhong, Wenwen; Xiong, Wei; Tang, Wenyu

2014-01-01

In slope stability analysis, the limit equilibrium method is usually used to calculate the safety factor of slope based on Mohr-Coulomb criterion. However, Mohr-Coulomb criterion is restricted to the description of rock mass. To overcome its shortcomings, this paper combined Hoek-Brown criterion and limit equilibrium method and proposed an equation for calculating the safety factor of slope with limit equilibrium method in Hoek-Brown criterion through equivalent cohesive strength and the friction angle. Moreover, this paper investigates the impact of Hoek-Brown parameters on the safety factor of slope, which reveals that there is linear relation between equivalent cohesive strength and weakening factor D. However, there are nonlinear relations between equivalent cohesive strength and Geological Strength Index (GSI), the uniaxial compressive strength of intact rock σ ci , and the parameter of intact rock m i . There is nonlinear relation between the friction angle and all Hoek-Brown parameters. With the increase of D, the safety factor of slope F decreases linearly; with the increase of GSI, F increases nonlinearly; when σ ci is relatively small, the relation between F and σ ci is nonlinear, but when σ ci is relatively large, the relation is linear; with the increase of m i , F decreases first and then increases.

The Leadership Criterion in Technological Institute

International Nuclear Information System (INIS)

Carvalho, Marcelo Souza de; Cussa, Adriana Lourenco d'Avila; Suita, Julio Cezar

2005-01-01

This paper introduces the Direction's 'Decision Making Practice'. It has recently been reviewed with the merging of the beddings of the Leadership Criterion (CE-PNQ). These changes improved the control of institutional plans of action which are the result of the global performance critical analysis and other information associated with the Decision Making Practice. (author)

Spatial frequency discrimination: visual long-term memory or criterion setting?

Science.gov (United States)

Lages, M; Treisman, M

1998-02-01

A long-term sensory memory is believed to account for spatial frequency discrimination when reference and test stimuli are separated by long intervals. We test an alternative proposal: that discrimination is determined by the range of test stimuli, through their entrainment of criterion-setting processes. Experiments 1 and 2 show that the 50% point of the psychometric function is largely determined by the midpoint of the stimulus range, not by the reference stimulus. Experiment 3 shows that discrimination of spatial frequencies is similarly affected by orthogonal contextual stimuli and parallel contextual stimuli and that these effects can be explained by criterion-setting processes. These findings support the hypothesis that discrimination over long intervals is explained by the operation of criterion-setting processes rather than by long-term sensory retention of a neural representation of the stimulus.

Are better sleepers more engaged workers? A self-regulatory approach to sleep hygiene and work engagement.

Science.gov (United States)

Barber, Larissa; Grawitch, Matthew J; Munz, David C

2013-10-01

Previous research has emphasized facets of both the organizational environment and individual differences as predictors of work engagement. This study explored sleep hygiene as another important behavioural factor that may be related to work engagement. With a sample of 328 adult workers, we tested a multiple mediator model in which sleep hygiene predicts work engagement through one's appraisals of resource depletion stemming from demands (psychological strain) and general self-regulatory capacity (self-control). Results indicated that individuals who frequently engaged in poor sleep hygiene behaviours had lower self-regulatory capacity, experienced higher subjective depletion and were less engaged at work. Additionally, the path from poor sleep hygiene to decreased work engagement was attributed to perceptions of personal resources that are needed to exert self-regulatory energy at work. This is consistent with current self-regulatory theories suggesting that individuals have a limited amount of resources to allocate to demands and that the depletion of these resources can lead to stress and lower self-regulatory functioning in response to other demands. Specifically, poor sleep hygiene results in the loss of self-regulatory resources needed to be engaged in work tasks by impairing the after-work recovery process. Practical and research implications regarding sleep hygiene interventions for well-being and productivity improvement are discussed. Copyright © 2012 John Wiley & Sons, Ltd.

Predicting sun protection behaviors using protection motivation variables.

Science.gov (United States)

Ch'ng, Joanne W M; Glendon, A Ian

2014-04-01

Protection motivation theory components were used to predict sun protection behaviors (SPBs) using four outcome measures: typical reported behaviors, previous reported behaviors, current sunscreen use as determined by interview, and current observed behaviors (clothing worn) to control for common method bias. Sampled from two SE Queensland public beaches during summer, 199 participants aged 18-29 years completed a questionnaire measuring perceived severity, perceived vulnerability, response efficacy, response costs, and protection motivation (PM). Personal perceived risk (similar to threat appraisal) and response likelihood (similar to coping appraisal) were derived from their respective PM components. Protection motivation predicted all four SPB criterion variables. Personal perceived risk and response likelihood predicted protection motivation. Protection motivation completely mediated the effect of response likelihood on all four criterion variables. Alternative models are considered. Strengths and limitations of the study are outlined and suggestions made for future research.

Choice is good, but relevance is excellent: autonomy-enhancing and suppressing teacher behaviours predicting students' engagement in schoolwork.

Science.gov (United States)

Assor, Avi; Kaplan, Haya; Roth, Guy

2002-06-01

This article examines two questions concerning teacher-behaviours that are characterised in Self-Determination Theory (Ryan & Deci, 2000) as autonomy-supportive or suppressive: (1) Can children differentiate among various types of autonomy-enhancing and suppressing teacher behaviours? (2) Which of those types of behaviour are particularly important in predicting feelings toward and engagement in schoolwork? It was hypothesised that teacher behaviours that help students to understand the relevance of schoolwork for their personal interests and goals are particularly important predictors of engagement in schoolwork. Israeli students in grades 3-5 (N = 498) and in grades 6-8 (N = 364) completed questionnaires assessing the variables of interest. Smallest Space Analyses indicated that both children and early adolescents can differentiate among three types of autonomy enhancing teacher behaviours - fostering relevance, allowing criticism, and providing choice - and three types of autonomy suppressing teacher behaviours - suppressing criticism, intruding, and forcing unmeaningful acts. Regression analyses supported the hypothesis concerning the importance of teacher behaviours that clarify the personal relevance of schoolwork. Among the autonomy-suppressing behaviours, 'Criticism-suppression' was the best predictor of feelings and engagement. The findings underscore the active and empathic nature of teachers' role in supporting students' autonomy, and suggest that autonomy-support is important not only for early adolescents but also for children. Discussion of potential determinants of the relative importance of various autonomy-affecting teacher actions suggests that provision of choice should not always be viewed as a major indicator of autonomy support.

On the upper bound in the Bohm sheath criterion

Energy Technology Data Exchange (ETDEWEB)

Kotelnikov, I. A., E-mail: I.A.Kotelnikov@inp.nsk.su; Skovorodin, D. I., E-mail: D.I.Skovorodin@inp.nsk.su [Russian Academy of Sciences, Budker Institute of Nuclear Physics, Siberian Branch (Russian Federation)

2016-02-15

The question is discussed about the existence of an upper bound in the Bohm sheath criterion, according to which the Debye sheath at the interface between plasma and a negatively charged electrode is stable only if the ion flow velocity in plasma exceeds the ion sound velocity. It is stated that, with an exception of some artificial ionization models, the Bohm sheath criterion is satisfied as an equality at the lower bound and the ion flow velocity is equal to the speed of sound. In the one-dimensional theory, a supersonic flow appears in an unrealistic model of a localized ion source the size of which is less than the Debye length; however, supersonic flows seem to be possible in the two- and three-dimensional cases. In the available numerical codes used to simulate charged particle sources with a plasma emitter, the presence of the upper bound in the Bohm sheath criterion is not supposed; however, the correspondence with experimental data is usually achieved if the ion flow velocity in plasma is close to the ion sound velocity.

When does spiritual intelligence particularly predict job engagement? The mediating role of psychological empowerment.

Science.gov (United States)

Torabi, Mohsen; Nadali, Iman Zohoorian

2016-01-01

Regarding the importance of health care providers such as nurses who are always in stressful environments, it is imperative to better understand how they become more engaged in their work. The purpose of this paper is to focus on health care providers (nurses), and examine how the interaction between spiritual intelligence and psychological empowerment affect job engagement. This descriptive and quantitative study was conducted among nurses at the Faghihi Hospital in Shiraz, Iran in 2010. A sample of nurses ( n = 179) completed standard survey questionnaire including spiritual intelligence, psychological empowerment, and job engagement which included 5 questions for each dimensions. For testing the hypotheses of the study, results were analyzed through structural equation modeling (SEM) using LISREL 8.8. SEM revealed that psychological empowerment could fully mediate the relationship between spiritual intelligence and job engagement. However, the correlation between spiritual intelligence and job engagement was significant but weak using Pearson coefficient method. This can imply that psychological empowerment plays a crucial role in the relationship between spiritual intelligence and job engagement. This paper indicates that spiritual intelligence might affect different organizational parameters, directly or indirectly. Therefore, it is recommended that the researchers evaluate probable relationships between spiritual intelligence and other variables.

Investigating the impact of moulage on simulation engagement - A systematic review.

Science.gov (United States)

Stokes-Parish, Jessica B; Duvivier, Robbert; Jolly, Brian

2018-05-01

Simulation Based Education (SBE) is used as a primer for clinical education in nursing and other health professions. Participant engagement strategies and good debriefing have been identified as key for effective simulations. The environment in which the simulation is situated also plays a large role in the degree of participant engagement. Various cues are staged within simulations to enhance this engagement process. Moulage techniques are used in current-day simulation to mimic illnesses and wounds, acting as visual and tactile cues for the learner. To effectively utilise moulage in simulation, significant expense is required to train simulation staff and to purchase relevant equipment. Explore the use of moulage in simulation practice today and its influence on participant engagement. Using a systematic process to extract papers, we reviewed the literature with a critical-realist lens. CINAHL Complete, ERIC, Embase, Medline, PsycINFO, SCOPUS, Web of Science, Proquest, Science Direct and SAGE. 10 databases were systematically reviewed using the keyword "moulage" to answer the question "How does the authenticity of moulage impact on participant engagement?". 1318 records were identified prior to exclusion criterion were applied. 10 articles were targeted for review, following exclusion for English language and publication between 2005 and 2015. The resulting 10 papers were assessed for quality using the Medical Education Research Study Quality Instrument (MERSQI). The majority of papers were situated in dermatology teaching, with only one nursing paper. Study participants were both undergraduate and postgraduate. Most of the studies were undertaken at a university setting. No papers comprehensively addressed whether the authenticity of moulage influences learner engagement. Results were limited, yet clearly outline a widely held assumption that moulage is essential in simulation-based education for improved realism and subsequent learner engagement. Despite this

Criterion learning in rule-based categorization: simulation of neural mechanism and new data.

Science.gov (United States)

Helie, Sebastien; Ell, Shawn W; Filoteo, J Vincent; Maddox, W Todd

2015-04-01

In perceptual categorization, rule selection consists of selecting one or several stimulus-dimensions to be used to categorize the stimuli (e.g., categorize lines according to their length). Once a rule has been selected, criterion learning consists of defining how stimuli will be grouped using the selected dimension(s) (e.g., if the selected rule is line length, define 'long' and 'short'). Very little is known about the neuroscience of criterion learning, and most existing computational models do not provide a biological mechanism for this process. In this article, we introduce a new model of rule learning called Heterosynaptic Inhibitory Criterion Learning (HICL). HICL includes a biologically-based explanation of criterion learning, and we use new category-learning data to test key aspects of the model. In HICL, rule selective cells in prefrontal cortex modulate stimulus-response associations using pre-synaptic inhibition. Criterion learning is implemented by a new type of heterosynaptic error-driven Hebbian learning at inhibitory synapses that uses feedback to drive cell activation above/below thresholds representing ionic gating mechanisms. The model is used to account for new human categorization data from two experiments showing that: (1) changing rule criterion on a given dimension is easier if irrelevant dimensions are also changing (Experiment 1), and (2) showing that changing the relevant rule dimension and learning a new criterion is more difficult, but also facilitated by a change in the irrelevant dimension (Experiment 2). We conclude with a discussion of some of HICL's implications for future research on rule learning. Copyright © 2015 Elsevier Inc. All rights reserved.

Does exercise motivation predict engagement in objectively assessed bouts of moderate-intensity exercise? A self-determination theory perspective.

Science.gov (United States)

Standage, Martyn; Sebire, Simon J; Loney, Tom

2008-08-01

This study examined the utility of motivation as advanced by self-determination theory (Deci & Ryan, 2000) in predicting objectively assessed bouts of moderate intensity exercise behavior. Participants provided data pertaining to their exercise motivation. One week later, participants wore a combined accelerometer and heart rate monitor (Actiheart; Cambridge Neurotechnology Ltd) and 24-hr energy expenditure was estimated for 7 days. After controlling for gender and a combined marker of BMI and waist circumference, results showed autonomous motivation to positively predict moderate-intensity exercise bouts of >or=10 min, or=20 min, and an accumulation needed to meet public health recommendations for moderate intensity activity (i.e., ACSM/AHA guidelines). The present findings add bouts of objectively assessed exercise behavior to the growing body of literature that documents the adaptive consequences of engaging in exercise for autonomous reasons. Implications for practice and future work are discussed.

Association of goal orientation with work engagement and burnout in emergency nurses.

Science.gov (United States)

Adriaenssens, Jef; De Gucht, Veronique; Maes, Stan

2015-01-01

Goal orientation is a mindset towards the achievement of work-related goals, and it has been found to be related to occupational well-being. This study explored to what extent the 4-dimensional model of goal orientation adds additional variance to the explanation of burnout and work engagement in emergency nurses, after controlling for demographics, job characteristics and organizational variables. Self-report questionnaires including the Leiden Quality of Work Questionnaire for Nurses, Goal Orientation Questionnaire, Maslach Burnout Inventory and Utrecht Work Engagement Scale were completed by 170 out of 274 emergency nurses from 13 secondary Belgian hospitals (response rate 62%). Hierarchical multiple regression analyses were conducted. Goal orientation explained 14 and 13% of the variance in burnout and work engagement respectively. Job control was predictive of both outcomes. Job demands was a predictor of burnout, and social support predicted work engagement. Reward was related to work engagement. The mastery-approach goal orientation was strongly related to an increase in work engagement and to a decrease in burnout. The performance-avoidance goal orientation was strongly related to a decrease in work engagement and to an increase in burnout. The performance-approach and mastery-avoidance goal orientations were not predictive for the two outcome variables. Goal orientation explains additional variance in burnout and work engagement over and above work characteristics and organizational variables. A mastery-approach goal orientation appears to be beneficial while a performance-avoidance goal orientation is not. Hospital management should therefore invest in personal involvement and growth of ER-nurses and in a rewarding organizational culture.

Body composition in elderly people: effect of criterion estimates on predictive equations

International Nuclear Information System (INIS)

Baumgartner, R.N.; Heymsfield, S.B.; Lichtman, S.; Wang, J.; Pierson, R.N. Jr.

1991-01-01

The purposes of this study were to determine whether there are significant differences between two- and four-compartment model estimates of body composition, whether these differences are associated with aqueous and mineral fractions of the fat-free mass (FFM); and whether the differences are retained in equations for predicting body composition from anthropometry and bioelectric resistance. Body composition was estimated in 98 men and women aged 65-94 y by using a four-compartment model based on hydrodensitometry, 3 H 2 O dilution, and dual-photon absorptiometry. These estimates were significantly different from those obtained by using Siri's two-compartment model. The differences were associated significantly (P less than 0.0001) with variation in the aqueous fraction of FFM. Equations for predicting body composition from anthropometry and resistance, when calibrated against two-compartment model estimates, retained these systematic errors. Equations predicting body composition in elderly people should be calibrated against estimates from multicompartment models that consider variability in FFM composition

VALIDITY OF EXCESS ENTROPY PRODUCTION CRITERION OF THERMODYNAMIC STABILITY FOR NONEQUILIBRIUM STEADY STATES

Institute of Scientific and Technical Information of China (English)

吴金平

1991-01-01

The relation between the excess entropy production criterion of thermodynamic stabilityfor nonequilibrium states and kinetic linear stability principle is discussed. It is shown thatthe condition required by the excess entropy production criterion generally is sufficient, butnot necessary to judge the system stability. The condition required by the excess entropyproduction criterion is stronger than that of the linear stability principle. Only when theproduct matrix between the linearized matrix of kinetic equations and matrix of quadraticform of second-order excess entropy is symmetric, is the condition required by the excessentropy production criterion that the steady steate is asymptotically stable (δ_xP>0) necessaryand sufficient. The counterexample given by Fox to prove that the excess entropy, (δ~2S)ss,is not a Liapunov function is incorrect. Contradictory to his conclusion, the counterexampleis just a positive one that proves that the excess entropy is a Liapunov function. Moreover,the excess entropy production criterion is not limited by symmetric conditions of the linear-ized matrix of kinetic equations. The excess entropy around nonequilibrium steady states,(δ~2S)ss, is a Liapunov function of thermodynamic system.

The Mercier Criterion in Reversed Shear Tokamak Plasmas

International Nuclear Information System (INIS)

Kessel, C.; Chance, M.S.; Jardin, S.C.

1999-01-01

A recent numerical study has found that, contrary to conventional theoretical and experimental expectations, reversed shear plasmas are unstable primarily because the term proportional to the shear in the Mercier criterion is destabilizing. In the present study, the role of the magnetic shear, both local and global, is examined for various tokamak configurations with monotonic and non-monotonic safety factor profiles. The enhancement of the local shear due to the outward shift of the magnetic axis suggests that the latter are less susceptible to interchanges. Furthermore, by regrouping the terms in the criterion, the V'' term when differentiated instead with respect to the toroidal flux, is shown to absorb the dominant shear term. No Mercier instability is found for similar profiles as in the previous study

The mean lung dose (MLD). Predictive criterion for lung damage

Energy Technology Data Exchange (ETDEWEB)

Geyer, Peter; Appold, Steffen [Dresden University of Technology (TU Dresden), Clinic and Polyclinic for Radiotherapy and Radiation Oncology, Carl Gustav Carus Medical Faculty, Dresden (Germany); Herrmann, Thomas

2015-07-15

The purpose of this work was to prove the validity of the mean lung dose (MLD), widely used in clinical practice to estimate the lung toxicity of a treatment plan, by reevaluating experimental data from mini pigs. A total of 43 mini pigs were irradiated in one of four dose groups (25, 29, 33, and 37 Gy). Two regimens were applied: homogeneous irradiation of the right lung or partial irradiation of both lungs - including parts with lower dose - but with similar mean lung doses. The animals were treated with five fractions with a linear accelerator applying a CT-based treatment plan. The clinical lung reaction (breathing frequency) and morphological changes in CT scans were examined frequently during the 48 weeks after irradiation. A clear dose-effect relationship was found for both regimens of the trial. However, a straightforward relationship between the MLD and the relative number of responders with respect to different grades of increased breathing frequency for both regimens was not found. A morphologically based parameter NTCP{sub lung} was found to be more suitable for this purpose. The dependence of this parameter on the MLD is markedly different for the two regimens. In clinical practice, the MLD can be used to predict lung toxicity of a treatment plan, except for dose values that could lead to severe side effects. In the latter mentioned case, limitations to the predictive value of the MLD are possible. Such severe developments of a radiation-induced pneumopathy are better predicted by the NTCP{sub lung} formalism. The predictive advantage of this parameter compared to the MLD seems to remain in the evaluation and comparison of widely differing dose distributions, like in the investigated trial. (orig.) [German] Es soll unter Reevaluation von Tierversuchsdaten am Minischwein geprueft werden, ob die in der klinischen Praxis zur Beurteilung der Lungentoxizitaet eines Bestrahlungsregims regelhaft verwendete mittlere Lungendosis (MLD) eine zuverlaessige

Measuring Diversity and Inclusion in Academic Medicine: The Diversity Engagement Survey (DES)

Science.gov (United States)

Person, Sharina D.; Jordan, C. Greer; Allison, Jeroan J.; Fink Ogawa, Lisa M.; Castillo-Page, Laura; Conrad, Sarah; Nivet, Marc A.; Plummer, Deborah L.

2018-01-01

Purpose To produce a physician and scientific workforce capable of delivering high quality, culturally competent health care and research, academic medical centers must assess their capacity for diversity and inclusion and respond to identified opportunities. Thus, the Diversity Engagement Survey (DES) is presented as a diagnostic and benchmarking tool. Method The 22-item DES connects workforce engagement theory with inclusion and diversity constructs. Face and content validity were established based on decades of previous work to promote institutional diversity. The survey was pilot tested at a single academic medical center and subsequently administered at 13 additional academic medical centers. Cronbach alphas assessed internal consistency and Confirmatory Factor Analysis (CFA) established construct validity. Criterion validity was assessed by observed separation in scores for groups traditionally recognized to have less workforce engagement. Results The sample consisted of 13,694 individuals at 14 medical schools from across the U.S. who responded to the survey administered between 2011– 2012. The Cronbach alphas for inclusion and engagement factors (range: 0.68 to 0.85), CFA fit indices, and item correlations with latent constructs, indicated an acceptable model fit and that questions measured the intended concepts. DES scores clearly distinguished higher and lower performing institutions. The DES detected important disparities for black, women, and those who did not have heterosexual orientation. Conclusions This study demonstrated that the DES is a reliable and valid instrument for internal assessment and evaluation or external benchmarking of institutional progress in building inclusion and engagement. PMID:26466376

A Path-Independent Forming Limit Criterion for Stamping Simulations

International Nuclear Information System (INIS)

Zhu Xinhai; Chappuis, Laurent; Xia, Z. Cedric

2005-01-01

Forming Limit Diagram (FLD) has been proved to be a powerful tool for assessing necking failures in sheet metal forming analysis for majority of stamping operations over the last three decades. However, experimental evidence and theoretical analysis suggest that its applications are limited to linear or almost linear strain paths during its deformation history. Abrupt changes or even gradual deviations from linear strain-paths will shift forming limit curves from their original values, a situation that occurs in vast majority of sequential stamping operations such as where the drawing process is followed by flanging and re-strike processes. Various forming limit models have been put forward recently to provide remedies for the problem, noticeably stress-based and strain gradient-based forming limit criteria. This study presents an alternative path-independent forming limit criterion. Instead of traditional Forming Limit Diagrams (FLD) which are constructed in terms of major - minor principal strains throughout deformation history, the new criterion defines a critical effective strain ε-bar* as the limit strain for necking, and it is shown that ε-bar* can be expressed as a function of current strain rate state and material work hardening properties, without the need of explicitly considering strain-path effects. It is given by ε-bar* = f(β, k, n) where β = (dε 2 /dε 1 ) at current deformation state, and k and n are material strain hardening parameters if a power law is assumed. The analysis is built upon previous work by Storen and Rice [1975] and Zhu et al [2002] with the incorporation of anisotropic yield models such as Hill'48 for quadratic orthotropic yield and Hill'79 for non-quadratic orthotropic yield. Effects of anisotropic parameters such as R-values and exponent n-values on necking are investigated in detail for a variety of strain paths. Results predicted according to current analysis are compared against experimental data gathered from literature

The Criterion A problem revisited: controversies and challenges in defining and measuring psychological trauma.

Science.gov (United States)

Weathers, Frank W; Keane, Terence M

2007-04-01

The Criterion A problem in the field of traumatic stress refers to the stressor criterion for posttraumatic stress disorder (PTSD) and involves a number of fundamental issues regarding the definition and measurement of psychological trauma. These issues first emerged with the introduction of PTSD as a diagnostic category in the Diagnostic and Statistical Manual of Mental Disorders, Third Edition (DSM-III; American Psychiatric Association, 1980) and continue to generate considerable controversy. In this article, the authors provide an update on the Criterion A problem, with particular emphasis on the evolution of the DSM definition of the stressor criterion and the ongoing debate regarding broad versus narrow conceptualizations of traumatic events.

Failure criterion for graphene in biaxial loading—a molecular dynamics study

International Nuclear Information System (INIS)

Yazdani, Hessam; Hatami, Kianoosh

2015-01-01

Molecular dynamics simulations are carried out in order to develop a failure criterion for infinite/bulk graphene in biaxial tension. Stresses along the principal edge configurations of graphene (i.e. armchair and zigzag directions) are normalized to the corresponding uniaxial ultimate strength values. The combinations of normalized stresses resulting in the failure of graphene are used to define failure envelopes (limiting stress ratio surfaces). Results indicate that a bilinear failure envelope can be used to represent the tensile strength of graphene in biaxial loading at different temperatures with reasonable accuracy. A circular failure envelope is also introduced for practical applications. Both failure envelopes define temperature-independent upper limits for the feasible combinations of normalized stresses for a graphene sheet in biaxial loading. Predicted failure modes of graphene under biaxial loading are also shown and discussed. (paper)

The role of decision criterion in the Deese-Roediger-McDermott (DRM) false recognition memory: False memory falls and rises as a function of restriction on criterion setting.

Science.gov (United States)

Jou, Jerwen; Escamilla, Eric E; Arredondo, Mario L; Pena, Liann; Zuniga, Richard; Perez, Martin; Garcia, Clarissa

2018-02-01

How much of the Deese-Roediger-McDermott (DRM) false memory is attributable to decision criterion is so far a controversial issue. Previous studies typically used explicit warnings against accepting the critical lure to investigate this issue. The assumption is that if the false memory results from using a liberally biased criterion, it should be greatly reduced or eliminated by an explicit warning against accepting the critical lure. Results showed that warning was generally ineffective. We asked the question of whether subjects can substantially reduce false recognition without being warned when the test forces them to make a distinction between true and false memories. Using a two-alternative forced choice in which criterion plays a relatively smaller role, we showed that subjects could indeed greatly reduce the rate of false recognition. However, when the forced-choice restriction was removed from the two-item choice test, the rate of false recognition rebounded to that of the hit for studied list words, indicating the role of criterion in false recognition.

A criterion for selecting renewable energy processes

International Nuclear Information System (INIS)

Searcy, Erin; Flynn, Peter C.

2010-01-01

We propose that minimum incremental cost per unit of greenhouse gas (GHG) reduction, in essence the carbon credit required to economically sustain a renewable energy plant, is the most appropriate social criterion for choosing from a myriad of alternatives. The application of this criterion is illustrated for four processing alternatives for straw/corn stover: production of power by direct combustion and biomass integrated gasification and combined cycle (BIGCC), and production of transportation fuel via lignocellulosic ethanol and Fischer Tropsch (FT) syndiesel. Ethanol requires a lower carbon credit than FT, and direct combustion a lower credit than BIGCC. For comparing processes that make a different form of end use energy, in this study ethanol vs. electrical power via direct combustion, the lowest carbon credit depends on the relative values of the two energy forms. When power is 70$ MW h -1 , ethanol production has a lower required carbon credit at oil prices greater than 600$ t -1 (80$ bbl -1 ). (author)

Motivational indictors predicting the engagement, frequency and adequacy of rainwater tank maintenance

Science.gov (United States)

Mankad, Aditi; Greenhill, Murni

2014-01-01

Rainwater tank maintenance is a key social behavior in our changing environment, as tanks are being adopted worldwide to augment household water supplies and reduce urban water stress. The maintenance of rainwater tanks in urban areas is an important pro-environmental behavior that prevents public health issues arising from unhygienic tank use. This study examined motivational differences in maintenance behavior between householders with retrofitted and mandated (compulsory) rainwater tanks on their property (N = 1988). Results showed that retrofitted tank owners were more self-determined in their motivation than mandated owners. Amotivation and integrated regulation were both dominant predictors of engagement in tank maintenance, frequency and adequacy of tank maintenance activities. Those involved in more maintenance activity were likely driven to do so because of feelings of adherence to personal goals and values (e.g., as "sustainable" citizens), whereas individuals who experienced a lack of control and alienation from the activity were likely to view maintenance as meaningless. Thus, people with higher integrated regulation engaged in more tank maintenance activities, whereas more amotivated individuals engaged in less maintenance. As cities begin relying more on citizen self-sufficiency with respect to water and energy resources, issues relating to infrastructure maintenance and operation become paramount. Results show that motivation is important in the impetus to engage in a pro-environmental behavior as well as the frequency and accuracy with which that behavior is undertaken. Policy implications are further discussed.

Engaging Mexican Origin Families in a School-Based Preventive Intervention

Science.gov (United States)

Mauricio, Anne M.; Gonzales, Nancy A.; Millsap, Roger E.; Meza, Connie M.; Dumka, Larry E.; Germán, Miguelina; Genalo, M. Toni

2009-01-01

This study describes a culturally sensitive approach to engage Mexican origin families in a school-based, family-focused preventive intervention trial. The approach was evaluated via assessing study enrollment and intervention program participation, as well as examining predictors of engagement at each stage. Incorporating traditional cultural values into all aspects of engagement resulted in participation rates higher than reported rates of minority-focused trials not emphasizing cultural sensitivity. Family preferred language (English or Spanish) or acculturation status predicted engagement at all levels, with less acculturated families participating at higher rates. Spanish-language families with less acculturated adolescents participated at higher rates than Spanish-language families with more acculturated adolescents. Other findings included two-way interactions between family language and the target child’s familism values, family single- vs. dual-parent status, and number of hours the primary parent worked in predicting intervention participation. Editors’ Strategic Implications: The authors present a promising approach—which requires replication—to engaging and retaining Mexican American families in a school-based prevention program. The research also highlights the importance of considering acculturation status when implementing and studying culturally tailored aspects of prevention models. PMID:18004659

Engagement in mobile phone app for self-monitoring of emotional wellbeing predicts changes in mental health: MoodPrism.

Science.gov (United States)

Bakker, David; Rickard, Nikki

2018-02-01

Mobile apps are being used increasingly for mental health purposes, but evidence of their efficacy remains limited. The mechanisms underlying any effects of such apps are also unclear. This study examined the effectiveness of a self-monitoring mobile phone app by investigating the relationships between app engagement and mental health outcomes. Participants downloaded the MoodPrism app from the iOS and Android app stores, completing in-app assessments at start of use and again 30days later. The app prompted participants daily to complete a short mood questionnaire and formulated their responses into a mood diary. Data from 234 assessment completers (73% female; M age = 34.8 years) were analysed via hierarchical and mediation regressions. In this community sample, app engagement ratings predicted decreases in depression and anxiety, and increases in mental well-being. These effects were mediated by increases in emotional self-awareness, but only for participants who were clinically depressed or anxious at the time of the baseline assessment. Mental health literacy and coping self-efficacy did not play mediating roles. Findings suggest that other influential mediators may have not been measured, and future studies could verify the findings by using alternative methodologies, such as comparison with a control group. Engaging with an emotional wellbeing self-monitoring app may reduce depressive and anxious symptoms, and increase mental well-being. Increases in emotional self-awareness may mediate these changes in clinical populations, and further research is needed to reveal other mechanisms that mental health apps can utilize. Copyright © 2017 Elsevier B.V. All rights reserved.

Analytical Solution of Tunnel Surrounding Rock for Stress and Displacement Based on Lade–Duncan Criterion

Directory of Open Access Journals (Sweden)

MingZheng Zhu

2018-01-01

Full Text Available The deformation and failure of tunnel surrounding rock is the result of tunnel excavation disturbance and rock stress release. When the local stress of surrounding rock exceeds the elastic limit of rock mass, the plastic analysis of surrounding rock must be carried out to judge the stability of tunnel. In this study, the Lade–Duncan yield criterion is used to calculate the analytic solutions for the surrounding rock in a tunnel, and the radius and displacement of the plastic zone are deduced using an equilibrium equation. The plastic zone radius and displacement based on Lade–Duncan criterion and Mohr–Coulomb criterion were compared by using single-factor analysis method under the different internal friction angles, in situ stresses, and support resistances. The results show that the solutions of the radius and displacement of plastic zone calculated by the Lade–Duncan criterion are close to those of Mohr–Coulomb criterion under the high internal friction angle and support resistance or low in situ rock stress; however, the radius and displacement of the plastic zone calculated by the Lade–Duncan criterion are larger under normal circumstances, and the Lade–Duncan criterion is more applicable to the stability analysis of the surrounding rock in a tunnel.

Happiness Is the Way: Paths to Civic Engagement between Young Adulthood and Midlife

Science.gov (United States)

Fang, Shichen; Galambos, Nancy L.; Johnson, Matthew D.; Krahn, Harvey J.

2018-01-01

Directional associations between civic engagement and happiness were explored with longitudinal data from a community sample surveyed four times from age 22 to 43 (n = 690). Autoregressive cross-lagged models, controlling for cross-time stabilities in happiness and civic engagement, examined whether happiness predicted future civic engagement,…

Methodology to predict the initiation of multiple transverse fractures from horizontal wellbores

Energy Technology Data Exchange (ETDEWEB)

Crosby, D. G.; Yang, Z.; Rahman, S. S. [Univ. of New South Wales (Australia)

2001-10-01

The criterion based on Drucker and Prager which is designed to predict the pressure required to initiate secondary multiple transverse fractures in close proximity to primary fractures is discussed. Results based on this criterion compare favorably with those measured during a series of laboratory-scale hydraulic fracture interaction tests. It is concluded that the multiple fracture criterion and laboratory results demonstrate that transversely fractured horizontal wellbores have a limited capacity to resist the initiation of multiple fractures from adjacent perforations, or intersecting induced and natural fractures. 23 refs., 1 tab., 9 figs.

Inferring phylogenetic networks by the maximum parsimony criterion: a case study.

Science.gov (United States)

Jin, Guohua; Nakhleh, Luay; Snir, Sagi; Tuller, Tamir

2007-01-01

Horizontal gene transfer (HGT) may result in genes whose evolutionary histories disagree with each other, as well as with the species tree. In this case, reconciling the species and gene trees results in a network of relationships, known as the "phylogenetic network" of the set of species. A phylogenetic network that incorporates HGT consists of an underlying species tree that captures vertical inheritance and a set of edges which model the "horizontal" transfer of genetic material. In a series of papers, Nakhleh and colleagues have recently formulated a maximum parsimony (MP) criterion for phylogenetic networks, provided an array of computationally efficient algorithms and heuristics for computing it, and demonstrated its plausibility on simulated data. In this article, we study the performance and robustness of this criterion on biological data. Our findings indicate that MP is very promising when its application is extended to the domain of phylogenetic network reconstruction and HGT detection. In all cases we investigated, the MP criterion detected the correct number of HGT events required to map the evolutionary history of a gene data set onto the species phylogeny. Furthermore, our results indicate that the criterion is robust with respect to both incomplete taxon sampling and the use of different site substitution matrices. Finally, our results show that the MP criterion is very promising in detecting HGT in chimeric genes, whose evolutionary histories are a mix of vertical and horizontal evolution. Besides the performance analysis of MP, our findings offer new insights into the evolution of 4 biological data sets and new possible explanations of HGT scenarios in their evolutionary history.

Information criterion for the categorization quality evaluation

Directory of Open Access Journals (Sweden)

Michail V. Svirkin

2011-05-01

Full Text Available The paper considers the possibility of using the variation of information function as a quality criterion for categorizing a collection of documents. The performance of the variation of information function is being examined subject to the number of categories and the sample volume of the test document collection.

Optimization of Thermal Object Nonlinear Control Systems by Energy Efficiency Criterion.

Science.gov (United States)

Velichkin, Vladimir A.; Zavyalov, Vladimir A.

2018-03-01

This article presents the results of thermal object functioning control analysis (heat exchanger, dryer, heat treatment chamber, etc.). The results were used to determine a mathematical model of the generalized thermal control object. The appropriate optimality criterion was chosen to make the control more energy-efficient. The mathematical programming task was formulated based on the chosen optimality criterion, control object mathematical model and technological constraints. The “maximum energy efficiency” criterion helped avoid solving a system of nonlinear differential equations and solve the formulated problem of mathematical programming in an analytical way. It should be noted that in the case under review the search for optimal control and optimal trajectory reduces to solving an algebraic system of equations. In addition, it is shown that the optimal trajectory does not depend on the dynamic characteristics of the control object.

Work-family conflict and work engagement among mothers: Conscientiousness and neuroticism as moderators

Directory of Open Access Journals (Sweden)

Tracy J. Opie

2013-07-01

Research purpose: The job demand-resources model is utilised to investigate the moderating role of conscientiousness and neuroticism on the relationship between work-family conflict and work engagement. Motivation for the study: Working mothers are challenged to establish a balance between work and family life. The resulting work-family conflict can negatively affect well-being. It is thus necessary to explore personal factors that relate to work-family conflict, particularly in the South African context. Research design, approach and method: A quantitative, cross-sectional survey design was used. The sample (N = 267 was comprised of working mothers from several organisations. Data was gathered using the work-to-family conflict questionnaire, the Basic Traits Inventory and the Utrecht Work Engagement Scale. Main findings: The results indicated that work-family conflict negatively predicts work engagement. Conscientiousness positively predicts work engagement, and neuroticism negatively predicts work engagement. A significant interaction effect was found for conscientiousness but not for neuroticism. The findings showed that for participants with high levels of conscientiousness, work engagement decreases significantly more with an increase in work-family conflict than for participants with low levels of conscientiousness. Practical/Managerial implications: Organisations should consider those individuals who have high levels of conscientiousness and low levels of neuroticism in the selection and placement of employees. In addition, organisations have a responsibility to provide conscientious women, particularly mothers, with adequate support to ensure that work-family conflict does not adversely impact their levels of work engagement.

Workplace engagement and workers' compensation claims as predictors for patient safety culture.

Science.gov (United States)

Thorp, Jonathon; Baqai, Waheed; Witters, Dan; Harter, Jim; Agrawal, Sangeeta; Kanitkar, Kirti; Pappas, James

2012-12-01

Demonstrate the relationship between employee engagement and workplace safety for predicting patient safety culture. Patient safety is an issue for the U.S. health-care system, and health care has some of the highest rates of nonfatal workplace injuries. Understanding the types of injuries sustained by health-care employees, the type of safety environment employees of health-care organizations work in, and how employee engagement affects patient safety is vital to improving the safety of both employees and patients. The Gallup Q survey and an approved, abbreviated, and validated subset of questions from the Hospital Survey on Patient Safety Culture were administered to staff at a large tertiary academic medical center in 2007 and 2009. After controlling for demographic variables, researchers conducted a longitudinal, hierarchical linear regression analysis to study the unique contributions of employee engagement, changes in employee engagement, and employee safety in predicting patient safety culture. Teams with higher baseline engagement, more positive change in engagement, fewer workers' compensation claims, and fewer part-time associates in previous years had stronger patient safety cultures in 2009. Baseline engagement and change in engagement were the strongest independent predictors of patient safety culture in 2009. Engagement and compensation claims were additive and complimentary predictors, independent of other variables in the analysis, including the demographic composition of the workgroups in the study. A synergistic effect exists between employee engagement and decreased levels of workers' compensation claims for improving patient safety culture. Organizations can improve engagement and implement safety policies, procedures, and devices for employees with an ultimate effect of improving patient safety culture.

Analysis of engagement behavior in children during dyadic interactions using prosodic cues.

Science.gov (United States)

Gupta, Rahul; Bone, Daniel; Lee, Sungbok; Narayanan, Shrikanth

2016-05-01

Child engagement is defined as the interaction of a child with his/her environment in a contextually appropriate manner. Engagement behavior in children is linked to socio-emotional and cognitive state assessment with enhanced engagement identified with improved skills. A vast majority of studies however rely solely, and often implicitly, on subjective perceptual measures of engagement. Access to automatic quantification could assist researchers/clinicians to objectively interpret engagement with respect to a target behavior or condition, and furthermore inform mechanisms for improving engagement in various settings. In this paper, we present an engagement prediction system based exclusively on vocal cues observed during structured interaction between a child and a psychologist involving several tasks. Specifically, we derive prosodic cues that capture engagement levels across the various tasks. Our experiments suggest that a child's engagement is reflected not only in the vocalizations, but also in the speech of the interacting psychologist. Moreover, we show that prosodic cues are informative of the engagement phenomena not only as characterized over the entire task (i.e., global cues), but also in short term patterns (i.e., local cues). We perform a classification experiment assigning the engagement of a child into three discrete levels achieving an unweighted average recall of 55.8% (chance is 33.3%). While the systems using global cues and local level cues are each statistically significant in predicting engagement, we obtain the best results after fusing these two components. We perform further analysis of the cues at local and global levels to achieve insights linking specific prosodic patterns to the engagement phenomenon. We observe that while the performance of our model varies with task setting and interacting psychologist, there exist universal prosodic patterns reflective of engagement.

Optimal Conformal Polynomial Projections for Croatia According to the Airy/Jordan Criterion

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Dražen Tutić

2009-05-01

Full Text Available The paper describes optimal conformal polynomial projections for Croatia according to the Airy/Jordan criterion. A brief introduction of history and theory of conformal mapping is followed by descriptions of conformal polynomial projections and their current application. The paper considers polynomials of degrees 1 to 10. Since there are conditions in which the 1st degree polynomial becomes the famous Mercator projection, it was not considered specifically for Croatian territory. The area of Croatia was defined as a union of national territory and the continental shelf. Area definition data were taken from the Euro Global Map 1:1 000 000 for Croatia, as well as from two maritime delimitation treaties. Such an irregular area was approximated with a regular grid consisting of 11 934 ellipsoidal trapezoids 2' large. The Airy/Jordan criterion for the optimal projection is defined as minimum of weighted mean of Airy/Jordan measure of distortion in points. The value of the Airy/Jordan criterion is calculated from all 11 934 centres of ellipsoidal trapezoids, while the weights are equal to areas of corresponding ellipsoidal trapezoids. The minimum is obtained by Nelder and Mead’s method, as implemented in the fminsearch function of the MATLAB package. Maps of Croatia representing the distribution of distortions are given for polynomial degrees 2 to 6 and 10. Increasing the polynomial degree results in better projections considering the criterion, and the 6th degree polynomial provides a good ratio of formula complexity and criterion value.

The prediction of spherical aberration with schematic eyes.

Science.gov (United States)

Liou, H L; Brennan, N A

1996-07-01

Many model eyes have been proposed; they differ in optical characteristics and therefore have different aberrations and image quality. In predicting the visual performance of the eye, we are most concerned with the central foveal vision. Spherical aberration is the only on-axis monochromatic aberration and can be used as a criterion to assess the degree of resemblance of eye models to the human eye. We reviewed and compiled experimental values of the spherical aberration of the eye, calculated the spherical aberration of several different categories of model eyes and compared the calculated results to the experimental data. Results show an over-estimation of spherical aberration by all models, the finite schematic eyes predicting values of spherical aberration closest to the experimental data. Current model eyes do not predict the average experimental values of the spherical aberration of the eye. A new model eye satisfying this assessment criterion is required for investigations of the visual performance of the eye.

Electronics. Criterion-Referenced Test (CRT) Item Bank.

Science.gov (United States)

Davis, Diane, Ed.

This document contains 519 criterion-referenced multiple choice and true or false test items for a course in electronics. The test item bank is designed to work with both the Vocational Instructional Management System (VIMS) and the Vocational Administrative Management System (VAMS) in Missouri. The items are grouped into 15 units covering the…

Satisfying the Einstein-Podolsky-Rosen criterion with massive particles

Science.gov (United States)

Peise, J.; Kruse, I.; Lange, K.; Lücke, B.; Pezzè, L.; Arlt, J.; Ertmer, W.; Hammerer, K.; Santos, L.; Smerzi, A.; Klempt, C.

2016-03-01

In 1935, Einstein, Podolsky and Rosen (EPR) questioned the completeness of quantum mechanics by devising a quantum state of two massive particles with maximally correlated space and momentum coordinates. The EPR criterion qualifies such continuous-variable entangled states, as shown successfully with light fields. Here, we report on the production of massive particles which meet the EPR criterion for continuous phase/amplitude variables. The created quantum state of ultracold atoms shows an EPR parameter of 0.18(3), which is 2.4 standard deviations below the threshold of 1/4. Our state presents a resource for tests of quantum nonlocality with massive particles and a wide variety of applications in the field of continuous-variable quantum information and metrology.

The Bohm Criterion for Radiofrequency Discharges - a Numerical Verification Based on Poisson Equation

NARCIS (Netherlands)

Meijer, P. M.; W. J. Goedheer,

1993-01-01

Recently it was shown that, by using the analysis of electrostatic waves entering the plasma-sheath edge, the direct-current (dc) Bohm criterion also holds for discharges under radio-frequency (rf) conditions. In this paper, the influence of Bohm's criterion on the sheath characteristics for

An Integrated Pruning Criterion for Ensemble Learning Based on Classification Accuracy and Diversity

DEFF Research Database (Denmark)

Fu, Bin; Wang, Zhihai; Pan, Rong

2013-01-01

be further considered while designing a pruning criterion is presented, and then an effective definition of diversity is proposed. The experimental results have validated that the given pruning criterion could single out the subset of classifiers that show better performance in the process of hill...

Low beta rigid mode stability criterion for an arbitrary Larmor radius plasma

International Nuclear Information System (INIS)

Berk, H.L.; Wong, H.V.

1987-05-01

The low beta flute interchange dispersion relation for rigid displacement perturbation of axisymmetric plasma equilibria with arbitrary Larmor radius particles and field line curvature, large compared to the plasma radius, is derived. The equilibrium particle orbits are characterized by two constants of motion, energy and angular momentum, and a third adiabatic invariant derived from the rapid radial motion. The Vlasov equation is integrated, assuming that the mode frequency, axial ''bounce'' frequency, and particle drift frequency are small compared to the cyclotron frequency, and it is demonstrated that the plasma response to a rigid perturbation has a universal character independent of Larmor radius. As a result the interchange instability is the same as that predicted from conventional MHD theory. However, a new prediction, more optimistic than earlier work, is found for the low density threshold of systems like Migma, which are disc-shaped, that is, the axial extent Δz is less than the radial extent r 0 . For Δz/sub r 0 / much less than 1, the stability criterion is determined by the total particle number. Whereas the older theory (Δz/sub r 0 / much greater than 1) predicted instability at about the densities achieved in actual Migma experiments, the present theory (Δz/sub r 0 / much less than 1) indicates that the experimental results were for plasmas with particle number below the interchange threshold

Take care of well-being: how facilitators and engagement predict performance of university students

Directory of Open Access Journals (Sweden)

Isabel M. Martínez

2016-03-01

Full Text Available The interest in developing a high quality educational system requires constant research of the variables involved in the teaching-learning process. Among these variables, social and academic facilitators are important because there is empirical evidence about their positive relationship with engagement, commitment, self-efficacy, happiness and satisfaction in the academic context. Moreover, the psychological well-being of university students (i.e., engagement showed to positively affect future academic success. In line, the aim of this study is twofold. First, the relevance of social and university academic facilitators was analyzed depending on the faculty of belonging. Second, the effect of social (e.g., Good relationship with classmates and academic facilitators (e.g., Updated website with new information and easily accessible as well as academic engagement on academic performance (i.e., GPA was tested. The sample consisted of 965 University students. The ANOVAs’ results showed the existence of statistically significant differences in social and university academic facilitators among the different faculties.  Regression analyses demonstrated that social (but not university’s facilitators and academic engagement were positively related to academic performance. Additionally, the interaction between social facilitators and academic engagement was positively related to academic performance.  The effect was also significant when controlling for gender and faculty. The identification of different facilitators allows to develop different activities depending on the faculty, as well as leading to the optimization of teaching-learning process. Moreover, academic facilitators do not affect academic performance. From a practical view, it means that specific interventions can be implemented during the course so that students’ social facilitators and engagement increase.

Coupling Effect of Intruding Water and Inherent Gas on Coal Strength Based on the Improved (Mohr-Coulomb Failure Criterion

Directory of Open Access Journals (Sweden)

Yiyu Lu

2016-11-01

Full Text Available When employing hydraulic processes to increase gas drainage efficiency in underground coal mines, coal seams become a three-phase medium, containing water intruding into the coal pores with the inherent occurrence of gas. This can change the stress state of the coal and cause instability. This work studied the mechanical properties of coal containing water and gas and derived an appropriate failure criterion. Based on mixture theory of unsaturated porous media, the effective stress of coal, considering the interaction of water and gas, was analyzed, and the failure criterion established by combining this with the Mohr–Coulomb criterion. By introducing the stress factor of matrix suction and using fitted curves of experimentally determined matrix suction and moisture content, the relationships between coal strength, gas pressure, and moisture content were determined. To verify the established strength theory, a series of triaxial compression strength tests of coal containing water and gas were carried out on samples taken from the Songzao, Pingdingshan, and Tashan mines in China. The experimental results correlated well with the theoretical predictions. The results showed a linear decrease in the peak strength of coal with increasing gas pressure and an exponential reduction in peak strength with increasing moisture content. The strength theory of coal containing water and gas can become an important part of multiphase medium damage theory.

Perspective-Taking Increases Willingness to Engage in Intergroup Contact

OpenAIRE

Wang, Cynthia S.; Kenneth, Tai; Ku, Gillian; Galinsky, Adam D.

2014-01-01

The current research explored whether perspective-taking increases willingness to engage in contact with stereotyped outgroup members. Across three studies, we find that perspective-taking increases willingness to engage in contact with negatively-stereotyped targets. In Study 1, perspective-takers sat closer to, whereas stereotype suppressors sat further from, a hooligan compared to control participants. In Study 2, individual differences in perspective-taking tendencies predicted individual...

Crossover of work engagement among Japanese couples : perspective taking by both partners

NARCIS (Netherlands)

Bakker, A.B.; Shimazu, A.; Demerouti, E.; Shimada, K.; Kawakami, N.

2011-01-01

This study among 426 Japanese couples working in different occupational sectors tested the hypothesis that perspective taking moderates the crossover of work engagement. More specifically, we predicted that husbands' work engagement would cross over to their wives, particularly when wives scored

Examining the Relations among Student Motivation, Engagement, and Retention in a MOOC: A Structural Equation Modeling Approach

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Yao Xiong

2015-09-01

Full Text Available Students who are enrolled in MOOCs tend to have different motivational patterns than fee-paying college students. A majority of MOOC students demonstrate characteristics akin more to "tourists" than formal learners. As a consequence, MOOC students’ completion rate is usually very low. The current study examines the relations among student motivation, engagement, and retention using structural equation modeling and data from a Penn State University MOOC. Three distinct types of motivation are examined: intrinsic motivation, extrinsic motivation, and social motivation. Two main hypotheses are tested: (a motivation predicts student course engagement; and (b student engagement predicts their retention in the course. The results show that motivation is significantly predictive of student course engagement. Furthermore, engagement is a strong predictor of retention. The findings suggest that promoting student motivation and monitoring individual students’ online activities might improve course retention

Zero mass field quantization and Kibble's long-range force criterion for the Goldstone theorem

International Nuclear Information System (INIS)

Wright, S.H.

1981-01-01

The central theme of the dissertation is an investigation of the long-range force criterion used by Kibble in his discussion of the Goldstone Theorem. This investigation is broken up into the following sections: I. Introduction. Spontaneous symmetry breaking, the Goldstone Theorem and the conditions under which it holds are discussed. II. Massless Wave Expansions. In order to make explicit calculations of the operator commutators used in applying Kibble's criterion, it is necessary to work out the operator expansions for a massless field. Unusual results are obtained which include operators corresponding to classical macroscopic field modes. III. The Kibble Criterion for Simple Models Exhibiting Spontaneously Broken Symmetries. The results of the previous section are applied to simple models with spontaneously broken symmetries, namely, the real scalar massless field and the Goldstone model without gauge coupling. IV. The Higgs Mechanism in Classical Field Theory. It is shown that the Higgs Mechanism has a simple interpretation in terms of classical field theory, namely, that it arises from a derivative coupling term between the Goldstone fields and the gauge fields. V. The Higgs Mechanism and Kibble's Criterion. This section draws together the material discussed in sections II to IV. Explicit calculations are made to evaluate Kibble's criterion on a Goldstone-Higgs type of model in the Coulomb gauge. It is found, as expected, that the criterion is not met, but not for reasons relating to the range of the mediating force. By referring to the findings of sections III and IV, it is concluded that the common denominator underlying both the Higgs Mechanism and the failure of Kibble's criterion is a structural aspect of the field equations: derivative coupling between fields

A characterization of optimal portfolios under the tail mean-variance criterion

OpenAIRE

Owadally, I.; Landsman, Z.

2013-01-01

The tail mean–variance model was recently introduced for use in risk management and portfolio choice; it involves a criterion that focuses on the risk of rare but large losses, which is particularly important when losses have heavy-tailed distributions. If returns or losses follow a multivariate elliptical distribution, the use of risk measures that satisfy certain well-known properties is equivalent to risk management in the classical mean–variance framework. The tail mean–variance criterion...

An Improvement of the Anisotropy and Formability Predictions of Aluminum Alloy Sheets

Science.gov (United States)

Banabic, D.; Comsa, D. S.; Jurco, P.; Wagner, S.; Vos, M.

2004-06-01

The paper presents an yield criterion for orthotropic sheet metals and its implementation in a theoretical model in order to calculate the Forming Limit Curves. The proposed yield criterion has been validated for two aluminum alloys: AA3103-0 and AA5182-0, respectively. The biaxial tensile test of cross specimens has been used for the determination of the experimental yield locus. The new yield criterion has been implemented in the Marciniak-Kuczynski model for the calculus of limit strains. The calculated Forming Limit Curves have been compared with the experimental ones, determined by frictionless test: bulge test, plane strain test and uniaxial tensile test. The predicted Forming Limit Curves using the new yield criterion are in good agreement with the experimental ones.

Evidence for the Criterion Validity and Clinical Utility of the Pathological Narcissism Inventory

Science.gov (United States)

Thomas, Katherine M.; Wright, Aidan G. C.; Lukowitsky, Mark R.; Donnellan, M. Brent; Hopwood, Christopher J.

2012-01-01

In this study, the authors evaluated aspects of criterion validity and clinical utility of the grandiosity and vulnerability components of the Pathological Narcissism Inventory (PNI) using two undergraduate samples (N = 299 and 500). Criterion validity was assessed by evaluating the correlations of narcissistic grandiosity and narcissistic…

Botanical Criterions of Quchan Baharkish pastureland in Khorasan ...

African Journals Online (AJOL)

ADOWIE PERE

Botanical Criterions of Quchan Baharkish pastureland in Khorasan Razavi Province,. Iran. *1SAEED, JAHEDI POUR 2ALIREZA, KOOCHEKI 3MEHDI, NASSIRI. MAHALLATI 4PARVIZ REZVANI MOGHADDAM. 1Department of Agroecology and Plant Breeding, Ferdowsi. University of Mashhad International Campus, ...

We Engage, Therefore They Trust? A Study of Social Media Engagement and Public Trust in Science

Science.gov (United States)

Hwong, Y. L.; Oliver, C.; Van Kranendonk, M. J.

2017-12-01

Our society relies heavily on the trust that the public places in science to work. Given science's importance, the growing distrust in science is a cause for concern. Thanks to their participatory nature, social media have been touted as the promising tool for public engagement to restore public trust in science. These digital platforms have transformed the landscape of science communication yet little is known about their impact on public trust in science. This study probed several aspects of public trust in science as expressed on Twitter, focusing on two related science issues: space science and climate change. Our datasets comprised of 10,000 randomly sampled tweets over a month's period in 2016. We used human annotation and machine learning as our approach. Results indicated that the perceived contentiousness of a science issue has a significant impact on public trust. The level of distrust is higher in the climate change tweets than in the space science tweets, despite climate scientists being almost four times as active as space scientists in engaging with sceptics. However, people who engaged with scientists in the climate change network displayed a higher level of trust in science compared with those who did not. This effect was not observed in the space science network - in this network, there is no significant difference in trust levels between people who engaged with scientists and those who did not. Additionally, our machine learning study revealed that trust in science (as conveyed by tweets) can be predicted. The supervised learning algorithm that we developed was able to predict the trust labels of tweets in our sample with an accuracy of 84%. A further feature analysis indicated that similarity, presence of URL and authenticity are the properties of trust-inspiring tweets. Based on these findings, we argue that social media science communication is not as straightforward as `we engage, therefore they trust'. Public attitude towards science is often

Role Stress and Work Engagement as Antecedents of Job Satisfaction: Results From Portugal

Directory of Open Access Journals (Sweden)

Daniel Moura

2014-05-01

Full Text Available With more organizations looking for employees who take initiative and respond creatively to the challenges of the job, engagement becomes important at both individual and organizational levels. Engaged employees are generally more satisfied with their work, committed and effective at work. According to the JDR model (Schaufeli & Bakker, 2004, engagement may be produced by two types of working conditions: job demands (i.e., role stress and job resources (i.e., self-efficacy. This study examines the role of role stress (role ambiguity and role conflict and work engagement as antecedents of job satisfaction. A cross sectional study using online questionnaires was conducted. The sample consisted of 312 Portuguese workers. Hierarchical multiple regressions analyses have revealed that job satisfaction was significantly predicted by role conflict and work engagement. Results support JDR model by showing that positive outcomes, such as job satisfaction, may be predicted by motivational process and job demands. On a practical level, JDR model provides a framework for understanding motivating workplaces and engaged and satisfied employees.

Happiness, work engagement and organisational commitment of support staff at a tertiary education institution in South Africa

Directory of Open Access Journals (Sweden)

Lyndsay K. Field

2011-09-01

Research purpose: The purpose of the research was to determine the relationship between happiness, work engagement and organisational commitment and to determine whether happiness and work engagement hold predictive value for the organisational commitment of support staff. Motivation for the study: This study aims to enable the identification of a link between happiness, work engagement and organisational commitment and to identify a predictive value of the model. Research design, approach and method: The researchers used a cross-sectional survey design. They used a sample of 123 (N = 123 support staff members from a tertiary education institution in South Africa. The researchers used four demographic questionnaires for the research. These were the ‘Satisfaction with Life Scale’ (SWLS, the ‘Well-Being Questionnaire’ (WBQ, the ‘Utrecht Work Engagement Scale’ (UWES and the ‘Organisational Commitment Questionnaire’ (OCQ. Main findings: The researchers found a significant positive relationship between affective organisational commitment and work engagement, as well as between affective organisational commitment and happiness (as the SWLS and WBQ measure. They found a significant positive relationship between work engagement and happiness. Finally, the results showed that happiness and work engagement have predictive value for affective organisational commitment. Practical/managerial implications: Happiness and work engagement have predictive value for affective organisational commitment. Therefore, institutions should carefully tailor any implementation programme or initiative to address this relationship. Contribution/value-add: The findings will benefit both managers and workers. Institutions should consider evaluating the levels of happiness and work engagement of their support staff to address the issue of the organisational commitment of their employees.

Ignition criterion for heterogeneous energetic materials based on hotspot size-temperature threshold

Science.gov (United States)

Barua, A.; Kim, S.; Horie, Y.; Zhou, M.

2013-02-01

A criterion for the ignition of granular explosives (GXs) and polymer-bonded explosives (PBXs) under shock and non-shock loading is developed. The formulation is based on integration of a quantification of the distributions of the sizes and locations of hotspots in loading events using a cohesive finite element method (CFEM) developed recently and the characterization by Tarver et al. [C. M. Tarver et al., "Critical conditions for impact- and shock-induced hot spots in solid explosives," J. Phys. Chem. 100, 5794-5799 (1996)] of the critical size-temperature threshold of hotspots required for chemical ignition of solid explosives. The criterion, along with the CFEM capability to quantify the thermal-mechanical behavior of GXs and PBXs, allows the critical impact velocity for ignition, time to ignition, and critical input energy at ignition to be determined as functions of material composition, microstructure, and loading conditions. The applicability of the relation between the critical input energy (E) and impact velocity of James [H. R. James, "An extension to the critical energy criterion used to predict shock initiation thresholds," Propellants, Explos., Pyrotech. 21, 8-13 (1996)] for shock loading is examined, leading to a modified interpretation, which is sensitive to microstructure and loading condition. As an application, numerical studies are undertaken to evaluate the ignition threshold of granular high melting point eXplosive, octahydro-1,3,5,7-tetranitro-1,2,3,5-tetrazocine (HMX) and HMX/Estane PBX under loading with impact velocities up to 350 ms-1 and strain rates up to 105 s-1. Results show that, for the GX, the time to criticality (tc) is strongly influenced by initial porosity, but is insensitive to grain size. Analyses also lead to a quantification of the differences between the responses of the GXs and PBXs in terms of critical impact velocity for ignition, time to ignition, and critical input energy at ignition. Since the framework permits

Characteristics of Criterion-Referenced Instruments: Implications for Materials Selection for the Learning Disabled.

Science.gov (United States)

Blasi, Joyce F.

Discussed are characteristics of criterion referenced reading tests for use with learning disabled (LD) children, and analyzed are the Basic Educational Skills Inventory (BESI), the Prescriptive Reading Inventory (PRI), and the Cooper-McGuire Diagnostic Work-Analysis Test (CooperMcGuire). Criterion referenced tests are defined; and problems in…

Genes, psychological traits and civic engagement

Science.gov (United States)

Dawes, Christopher T.; Settle, Jaime E.; Loewen, Peter John; McGue, Matt; Iacono, William G.

2015-01-01

Civic engagement is a classic example of a collective action problem: while civic participation improves life in the community as a whole, it is individually costly and thus there is an incentive to free ride on the actions of others. Yet, we observe significant inter-individual variation in the degree to which people are in fact civically engaged. Early accounts reconciling the theoretical prediction with empirical reality focused either on variation in individuals’ material resources or their attitudes, but recent work has turned to genetic differences between individuals. We show an underlying genetic contribution to an index of civic engagement (0.41), as well as for the individual acts of engagement of volunteering for community or public service activities (0.33), regularly contributing to charitable causes (0.28) and voting in elections (0.27). There are closer genetic relationships between donating and the other two activities; volunteering and voting are not genetically correlated. Further, we show that most of the correlation between civic engagement and both positive emotionality and verbal IQ can be attributed to genes that affect both traits. These results enrich our understanding of the way in which genetic variation may influence the wide range of collective action problems that individuals face in modern community life. PMID:26503688

Changing the criterion for memory conformity in free recall and recognition.

Science.gov (United States)

Wright, Daniel B; Gabbert, Fiona; Memon, Amina; London, Kamala

2008-02-01

People's responses during memory studies are affected by what other people say. This memory conformity effect has been shown in both free recall and recognition. Here we examine whether accurate, inaccurate, and suggested answers are affected similarly when the response criterion is varied. In the first study, participants saw four pictures of detailed scenes and then discussed the content of these scenes with another participant who saw the same scenes, but with a couple of details changed. Participants were either told to recall everything they could and not to worry about making mistakes (lenient), or only to recall items if they were sure that they were accurate (strict). The strict instructions reduced the amount of inaccurate information reported that the other person suggested, but also reduced the number of accurate details recalled. In the second study, participants were shown a large set of faces and then their memory recognition was tested with a confederate on these and fillers. Here also, the criterion manipulation shifted both accurate and inaccurate responses, and those suggested by the confederate. The results are largely consistent with a shift in response criterion affecting accurate, inaccurate, and suggested information. In addition we varied the level of secrecy in the participants' responses. The effects of secrecy were complex and depended on the level of response criterion. Implications for interviewing eyewitnesses and line-ups are discussed.

Criterion of Semi-Markov Dependent Risk Model

Institute of Scientific and Technical Information of China (English)

Xiao Yun MO; Xiang Qun YANG

2014-01-01

A rigorous definition of semi-Markov dependent risk model is given. This model is a generalization of the Markov dependent risk model. A criterion and necessary conditions of semi-Markov dependent risk model are obtained. The results clarify relations between elements among semi-Markov dependent risk model more clear and are applicable for Markov dependent risk model.

The effect of emotions, promotion vs. prevention focus, and feedback on cognitive engagement

Directory of Open Access Journals (Sweden)

Wytykowska Agata

2015-09-01

Full Text Available The purpose of the study was to explore the role of emotions, promotion-prevention orientation and feedback on cognitive engagement. In the experiment participants had the possibility to engage in a categorization task thrice. After the first categorization all participants were informed that around 75% of their answers were correct. After the second categorization, depending on the experimental condition, participants received feedback either about success or failure. Involvement in the third categorization was depended on participants’ decision whether to take part in it or not. Each time, before and after categorization, the emotional state was assessed. Results showed that promotion orientation predicted experiencing curiosity before the task, which in turn led to a higher cognitive engagement in the first categorization. Promotion and prevention orientation moderated the type of emotional response to positive feedback. Promotion orientation also predicted cognitive engagement after the feedback of success was provided. Generally results confirmed the positive effect of positive emotions as well as promotion orientation on cognitive engagement.

Measuring teaching quality and student engagement in South Korea and The Netherlands

NARCIS (Netherlands)

van de Grift, Wim J.C.; Chun, Seyeoung; Maulana, Ridwan; Lee, Okhwa; Helms-Lorenz, Michelle

2017-01-01

Six observation scales for measuring the skills of teachers and 1 scale for measuring student engagement, assessed in South Korea and The Netherlands, are sufficiently reliable and offer sufficient predictive value for student engagement. A multigroup confirmatory factor analysis shows that the

No rationale for 1 variable per 10 events criterion for binary logistic regression analysis.

Science.gov (United States)

van Smeden, Maarten; de Groot, Joris A H; Moons, Karel G M; Collins, Gary S; Altman, Douglas G; Eijkemans, Marinus J C; Reitsma, Johannes B

2016-11-24

Ten events per variable (EPV) is a widely advocated minimal criterion for sample size considerations in logistic regression analysis. Of three previous simulation studies that examined this minimal EPV criterion only one supports the use of a minimum of 10 EPV. In this paper, we examine the reasons for substantial differences between these extensive simulation studies. The current study uses Monte Carlo simulations to evaluate small sample bias, coverage of confidence intervals and mean square error of logit coefficients. Logistic regression models fitted by maximum likelihood and a modified estimation procedure, known as Firth's correction, are compared. The results show that besides EPV, the problems associated with low EPV depend on other factors such as the total sample size. It is also demonstrated that simulation results can be dominated by even a few simulated data sets for which the prediction of the outcome by the covariates is perfect ('separation'). We reveal that different approaches for identifying and handling separation leads to substantially different simulation results. We further show that Firth's correction can be used to improve the accuracy of regression coefficients and alleviate the problems associated with separation. The current evidence supporting EPV rules for binary logistic regression is weak. Given our findings, there is an urgent need for new research to provide guidance for supporting sample size considerations for binary logistic regression analysis.

Why do firms engage in forward-looking search?

DEFF Research Database (Denmark)

Jissink, Tymen; Rohrbeck, René; Huizingh, Eelko K.R.E.

firms with a low level of slack resources engage to a much lower extent into forward-looking search, if they operate in high-competitive-intensity environments. Our findings not only carry important implications for predicting a firm’s engagement in forward-looking search, but also potentially...... performed below aspirations are less likely to engage in forward-looking search, suggesting that forward-looking search is not a form of problemistic search. In contrast, firms that have abundant uncommitted (slack) resources as well as firms expecting to outperform in the near future are engaging more...... into forward-looking search. We also find interaction effect between performance feedback and environmental characteristics. Interestingly firms with a high level of slack resources are only surpassing their less rich peers in forward-looking search, if they are in technologically turbulent environments. Also...

Carbon emissions and an equitable emission reduction criterion

International Nuclear Information System (INIS)

Golomb, Dan

1999-01-01

In 1995 the world-wide carbon emissions reached 5.8 billion metric tonnes per year (GTC/y). The Kyoto protocol calls for a reduction of carbon emissions from the developed countries (Annex I countries) of 6-8% below 1990 levels on the average, and unspecified commitments for the less developed (non-Annex I) countries. It is doubtful that the Kyoto agreement will be ratified by some parliaments, especially the USA Congress. Furthermore, it is shown that if the non-Annex I countries will not curtail their carbon emissions drastically, the global emissions will soar to huge levels by the middle of the next century. An equitable emission criterion is proposed which may lead to a sustainable rate of growth of carbon emissions, and be acceptable to all countries of the world. The criterion links the rate of growth of carbon emissions to the rate of growth of the Gross Domestic Product (GDP). A target criterion is proposed R = 0.15 KgC/SGDP, which is the current average for western European countries and Japan. This allows for both the growth of the GDP and carbon emissions. However, to reach the target in a reasonable time, the countries for which R≤ 0.3 would be allowed a carbon emission growth rate of 1%./y, and countries for which R≥ 0.3, 0.75%/y. It is shown that by 2050 the world-wide carbon emissions would reach about 10 GTC/y, which is about 3 times less than the Kyoto agreement would allow. (Author)

PTSD's risky behavior criterion: Relation with DSM-5 PTSD symptom clusters and psychopathology.

Science.gov (United States)

Contractor, Ateka A; Weiss, Nicole H; Dranger, Paula; Ruggero, Camilo; Armour, Cherie

2017-06-01

A new symptom criterion of reckless and self-destructive behaviors (E2) was recently added to posttraumatic stress disorder's (PTSD) diagnostic criteria in DSM-5, which is unsurprising given the well-established relation between PTSD and risky behaviors. Researchers have questioned the significance and incremental validity of this symptom criterion within PTSD's symptomatology. Unprecedented to our knowledge, we aim to compare trauma-exposed groups differing on their endorsement status of the risky behavior symptom on several psychopathology constructs (PTSD, depression, distress tolerance, rumination, anger). The sample included 123 trauma-exposed participants seeking mental health treatment (M age=35.70; 68.30% female) who completed self-report questionnaires assessing PTSD symptoms, depression, rumination, distress tolerance, and anger. Results of independent samples t-tests indicated that participants who endorsed the E2 criterion at a clinically significant level reported significantly greater PTSD subscale severity; depression severity; rumination facets of repetitive thoughts, counterfactual thinking, and problem-focused thinking; and anger reactions; and significantly less absorption and regulation (distress tolerance facets) compared to participants who did not endorse the E2 criterion at a clinically significant level. Results indicate the utility of the E2 criterion in identifying trauma-exposed individual with greater posttraumatic distress, and emphasize the importance of targeting such behaviors in treatment. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

On the Modified Barkhausen Criterion

DEFF Research Database (Denmark)

Lindberg, Erik; Murali, K.

2016-01-01

Oscillators are normally designed according to the Modified Barkhausen Criterion i.e. the complex pole pair is moved out in RHP so that the linear circuit becomes unstable. By means of the Mancini Phaseshift Oscillator it is demonstrated that the distortion of the oscillator may be minimized by i...... by introducing a nonlinear ”Hewlett Resistor” so that the complex pole-pair is in the RHP for small signals and in the LHP for large signals i.e. the complex pole pair of the instant linearized small signal model is moving around the imaginary axis in the complex frequency plane....

Prediction of cleavage crack propagation and arrest in a nuclear pressure vessel steel (16MND5) under thermal shock

International Nuclear Information System (INIS)

Yang, Xiaoyu

2015-01-01

The purpose of this PhD study is to predict the propagation and arrest of cleavage cracks in a French PWR vessel steel (16MND5). This is accomplished through use of a local criterion based on the critical stress calculated ahead of crack tip. Previous work has shown that fracture mechanism was cleavage associated with the ductile shear zone between the different planes of cracking. Thus, the critical stress at crack tip depends on stain rate. This thesis consists of numerical optimization, identification and validation of a local criterion based on experiments which have complex thermomechanical loads. The criterion accounts for various crack paths, deepening the knowledge about micro mechanisms during crack propagation in order to justify the established criterion. Criterion identification was carried out by using numerical simulations of tension tests performed on CT (Compact Tension) specimens at four different temperatures (-150 C, -125 C, -100 C and -75 C). The eXtended Finite Element Method (X-FEM) was used in CAST3M FE software to model dynamic crack propagation and arrest. The analysis results in 2D and 3D showed that the critical stress at crack tip increased with the inelastic strain rate. Therefore, a criterion based on the critical stress was established. An analytical model was developed to justify the identified criterion. The critical stress given by the local criterion was considered as the sum of the critical cleavage stress and the stress generated by the deformation of ligaments behind the crack tip. In order to quantify this phenomenon, measurements of ligaments' characteristics have been performed on fracture surfaces and on cross-sections of the specimens. The stress profile of the crack lips generated by ligaments was calculated by modeling of multi-cracks on specimen's cross-section. The contribution of stress generated by ligaments to the critical stress at crack tip was obtained with this method, and then the analytical model of

Prioritising transport infrastructure projects: towards a multi-criterion ...

African Journals Online (AJOL)

Kirstam

multi-criterion analysis (MCA), partial equilibrium analysis, project appraisal ... In the case of transport infrastructure projects, though, this is no mean ... vehicle ownership and mileage-based depreciation (an improved road network and/ .... urban, rural or regional development initiatives – they typically include one or more.

Decision models for use with criterion-referenced tests

NARCIS (Netherlands)

van der Linden, Willem J.

1980-01-01

The problem of mastery decisions and optimizing cutoff scores on criterion-referenced tests is considered. This problem can be formalized as an (empirical) Bayes problem with decisions rules of a monotone shape. Next, the derivation of optimal cutoff scores for threshold, linear, and normal ogive

Utilization of Durability Criterion to Develop Automotive Components

DEFF Research Database (Denmark)

Ricardo, Luiz Carlos Hernandes

2010-01-01

Today the automotive companies must reduce the time to development of new products with improvement in performance, durability and low cost reductions where possible. To achieve this goal the carmakers need to improve the design criterion of car systems like body, chassis and suspension component...

The Job Demands-Resources model as predictor of work identity and work engagement: A comparative analysis

Directory of Open Access Journals (Sweden)

Roslyn De Braine

2011-05-01

Research purpose: This study explored possible differences in the Job Demands-Resources model (JD-R as predictor of overall work engagement, dedication only and work-based identity, through comparative predictive analyses. Motivation for the study: This study may shed light on the dedication component of work engagement. Currently no literature indicates that the JD-R model has been used to predict work-based identity. Research design: A census-based survey was conducted amongst a target population of 23134 employees that yielded a sample of 2429 (a response rate of about 10.5%. The Job Demands- Resources scale (JDRS was used to measure job demands and job resources. A work-based identity scale was developed for this study. Work engagement was studied with the Utrecht Work Engagement Scale (UWES. Factor and reliability analyses were conducted on the scales and general multiple regression models were used in the predictive analyses. Main findings: The JD-R model yielded a greater amount of variance in dedication than in work engagement. It, however, yielded the greatest amount of variance in work-based identity, with job resources being its strongest predictor. Practical/managerial implications: Identification and work engagement levels can be improved by managing job resources and demands. Contribution/value-add: This study builds on the literature of the JD-R model by showing that it can be used to predict work-based identity.

Criterion and Construct Validity of an Isometric Midthigh-Pull Dynamometer for Assessing Whole-Body Strength in Professional Rugby League Players.

Science.gov (United States)

Dobbin, Nick; Hunwicks, Richard; Jones, Ben; Till, Kevin; Highton, Jamie; Twist, Craig

2018-02-01

To examine the criterion and construct validity of an isometric midthigh-pull dynamometer to assess whole-body strength in professional rugby league players. Fifty-six male rugby league players (33 senior and 23 youth players) performed 4 isometric midthigh-pull efforts (ie, 2 on the dynamometer and 2 on the force platform) in a randomized and counterbalanced order. Isometric peak force was underestimated (P  .05) between the predicted and peak force from the force platform and an adjusted R 2 (79.6%) that represented shrinkage of 0.4% relative to the cross-validation model (80%). Peak force was greater for the senior than the youth professionals using the dynamometer (2261.2 ± 222 cf 1725.1 ± 298.0 N, respectively; P isometric midthigh pull assessed using a dynamometer underestimates criterion peak force but is capable of distinguishing muscle-function characteristics between professional rugby league players of different standards.

On the gap-opening criterion of migrating planets in protoplanetary disks

OpenAIRE

Malik, Matej; Meru, Farzana; Mayer, Lucio; Meyer, Michael R.

2015-01-01

We perform two-dimensional hydrodynamical simulations to quantitatively explore the torque balance criterion for gap-opening (as formulated by Crida et al.) in a variety of disks when considering a migrating planet. We find that even when the criterion is satisfied, there are instances when planets still do not open gaps. We stress that gap-opening is not only dependent on whether a planet has the ability to open a gap, but whether it can do so quickly enough. This can be expressed as an addi...

A second perspective on the Amann–Schmiedl–Seifert criterion for non-equilibrium in a three-state system

International Nuclear Information System (INIS)

Jia, Chen; Chen, Yong

2015-01-01

In the work of Amann, Schmiedl and Seifert (2010 J. Chem. Phys. 132 041102), the authors derived a sufficient criterion to identify a non-equilibrium steady state (NESS) in a three-state Markov system based on the coarse-grained information of two-state trajectories. In this paper, we present a mathematical derivation and provide a probabilistic interpretation of the Amann–Schmiedl–Seifert (ASS) criterion. Moreover, the ASS criterion is compared with some other criterions for a NESS. (paper)

Perceived Need for Treatment and Engagement in Mental Health Services Among Community-Referred Racial/Ethnic Minority Adolescents.

Science.gov (United States)

Fisher, Jacqueline Horan; Lichvar, Emily; Hogue, Aaron; Dauber, Sarah

2018-03-10

This study examines clinical and family predictors of perceived need for treatment and engagement in mental health treatment services among community-referred racial/ethnic minority adolescents and their primary caregivers. Findings indicated that the majority of families perceived a need for treatment, but that perceived need was not associated with treatment engagement. Family factors (i.e., low cohesion and high conflict within the family) predicted perceived need for treatment among adolescents, whereas clinical factors (i.e., adolescent internalizing and externalizing symptomatology) predicted caregiver perceived need for adolescent treatment. Neither clinical nor family factors predicted treatment engagement.

On global stability criterion for neural networks with discrete and distributed delays

International Nuclear Information System (INIS)

Park, Ju H.

2006-01-01

Based on the Lyapunov functional stability analysis for differential equations and the linear matrix inequality (LMI) optimization approach, a new delay-dependent criterion for neural networks with discrete and distributed delays is derived to guarantee global asymptotic stability. The criterion is expressed in terms of LMIs, which can be solved easily by various convex optimization algorithms. Some numerical examples are given to show the effectiveness of proposed method

A Criterion for Stability of Synchronization and Application to Coupled Chua's Systems

International Nuclear Information System (INIS)

Wang Haixia; Lu Qishao; Wang Qingyun

2009-01-01

We investigate synchronization in an array network of nearest-neighbor coupled chaotic oscillators. By using of the Lyapunov stability theory and matrix theory, a criterion for stability of complete synchronization is deduced. Meanwhile, an estimate of the critical coupling strength is obtained to ensure achieving chaos synchronization. As an example application, a model of coupled Chua's circuits with linearly bidirectional coupling is studied to verify the validity of the criterion. (general)

A novel delay-dependent criterion for delayed neural networks of neutral type

International Nuclear Information System (INIS)

Lee, S.M.; Kwon, O.M.; Park, Ju H.

2010-01-01

This Letter considers a robust stability analysis method for delayed neural networks of neutral type. By constructing a new Lyapunov functional, a novel delay-dependent criterion for the stability is derived in terms of LMIs (linear matrix inequalities). A less conservative stability criterion is derived by using nonlinear properties of the activation function of the neural networks. Two numerical examples are illustrated to show the effectiveness of the proposed method.

Criterion-based laparoscopic training reduces total training time

NARCIS (Netherlands)

Brinkman, W.M.; Buzink, S.N.; Alevizos, L.; De Hingh, I.H.J.T.; Jakimowicz, J.J.

2011-01-01

The benefits of criterion-based laparoscopic training over time-oriented training are unclear. The purpose of this study is to compare these types of training based on training outcome and time efficiency. Methods During four training sessions within 1 week (one session per day) 34 medical interns

Measuring preschool learning engagement in the laboratory.

Science.gov (United States)

Halliday, Simone E; Calkins, Susan D; Leerkes, Esther M

2018-03-01

Learning engagement is a critical factor for academic achievement and successful school transitioning. However, current methods of assessing learning engagement in young children are limited to teacher report or classroom observation, which may limit the types of research questions one could assess about this construct. The current study investigated the validity of a novel assessment designed to measure behavioral learning engagement among young children in a standardized laboratory setting and examined how learning engagement in the laboratory relates to future classroom adjustment. Preschool-aged children (N = 278) participated in a learning-based Tangrams task and Story sequencing task and were observed based on seven behavioral indicators of engagement. Confirmatory factor analysis supported the construct validity for a behavioral engagement factor composed of six of the original behavioral indicators: attention to instructions, on-task behavior, enthusiasm/energy, persistence, monitoring progress/strategy use, and negative affect. Concurrent validity for this behavioral engagement factor was established through its associations with parent-reported mastery motivation and pre-academic skills in math and literacy measured in the laboratory, and predictive validity was demonstrated through its associations with teacher-reported classroom learning behaviors and performance in math and reading in kindergarten. These associations were found when behavioral engagement was observed during both the nonverbal task and the verbal story sequencing tasks and persisted even after controlling for child minority status, gender, and maternal education. Learning engagement in preschool appears to be successfully measurable in a laboratory setting. This finding has implications for future research on the mechanisms that support successful academic development. Copyright © 2017 Elsevier Inc. All rights reserved.

Corner-point criterion for assessing nonlinear image processing imagers

Science.gov (United States)

Landeau, Stéphane; Pigois, Laurent; Foing, Jean-Paul; Deshors, Gilles; Swiathy, Greggory

2017-10-01

Range performance modeling of optronics imagers attempts to characterize the ability to resolve details in the image. Today, digital image processing is systematically used in conjunction with the optoelectronic system to correct its defects or to exploit tiny detection signals to increase performance. In order to characterize these processing having adaptive and non-linear properties, it becomes necessary to stimulate the imagers with test patterns whose properties are similar to the actual scene image ones, in terms of dynamic range, contours, texture and singular points. This paper presents an approach based on a Corner-Point (CP) resolution criterion, derived from the Probability of Correct Resolution (PCR) of binary fractal patterns. The fundamental principle lies in the respectful perception of the CP direction of one pixel minority value among the majority value of a 2×2 pixels block. The evaluation procedure considers the actual image as its multi-resolution CP transformation, taking the role of Ground Truth (GT). After a spatial registration between the degraded image and the original one, the degradation is statistically measured by comparing the GT with the degraded image CP transformation, in terms of localized PCR at the region of interest. The paper defines this CP criterion and presents the developed evaluation techniques, such as the measurement of the number of CP resolved on the target, the transformation CP and its inverse transform that make it possible to reconstruct an image of the perceived CPs. Then, this criterion is compared with the standard Johnson criterion, in the case of a linear blur and noise degradation. The evaluation of an imaging system integrating an image display and a visual perception is considered, by proposing an analysis scheme combining two methods: a CP measurement for the highly non-linear part (imaging) with real signature test target and conventional methods for the more linear part (displaying). The application to

(No) Harm in Asking: Class, Acquired Cultural Capital, and Academic Engagement at an Elite University

Science.gov (United States)

Jack, Anthony Abraham

2016-01-01

How do undergraduates engage authority figures in college? Existing explanations predict class-based engagement strategies. Using in-depth interviews with 89 undergraduates at an elite university, I show how undergraduates with disparate precollege experiences differ in their orientations toward and strategies for engaging authority figures in…

A Generalized Evolution Criterion in Nonequilibrium Convective Systems

Science.gov (United States)

Ichiyanagi, Masakazu; Nisizima, Kunisuke

1989-04-01

A general evolution criterion, applicable to transport processes such as the conduction of heat and mass diffusion, is obtained as a direct version of the Le Chatelier-Braun principle for stationary states. The present theory is not based on any radical departure from the conventional one. The generalized theory is made determinate by proposing the balance equations for extensive thermodynamic variables which will reflect the character of convective systems under the assumption of local equilibrium. As a consequence of the introduction of source terms in the balance equations, there appear additional terms in the expression of the local entropy production, which are bilinear in terms of the intensive variables and the sources. In the present paper, we show that we can construct a dissipation function for such general cases, in which the premises of the Glansdorff-Prigogine theory are accumulated. The new dissipation function permits us to formulate a generalized evolution criterion for convective systems.

Refocusing criterion via sparsity measurements in digital holography.

Science.gov (United States)

Memmolo, Pasquale; Paturzo, Melania; Javidi, Bahram; Netti, Paolo A; Ferraro, Pietro

2014-08-15

Several automatic approaches have been proposed in the past to compute the refocus distance in digital holography (DH). However most of them are based on a maximization or minimization of a suitable amplitude image contrast measure, regarded as a function of the reconstruction distance parameter. Here we show that, by using the sparsity measure coefficient regarded as a refocusing criterion in the holographic reconstruction, it is possible to recover the focus plane and, at the same time, establish the degree of sparsity of digital holograms, when samples of the diffraction Fresnel propagation integral are used as a sparse signal representation. We employ a sparsity measurement coefficient known as Gini's index thus showing for the first time, to the best of our knowledge, its application in DH, as an effective refocusing criterion. Demonstration is provided for different holographic configurations (i.e., lens and lensless apparatus) and for completely different objects (i.e., a thin pure phase microscopic object as an in vitro cell, and macroscopic puppets) preparation.

A criterion of orthogonality on the assumption and restrictions in subgrid-scale modelling of turbulence

Energy Technology Data Exchange (ETDEWEB)

Fang, L. [LMP, Ecole Centrale de Pékin, Beihang University, Beijing 100191 (China); Co-Innovation Center for Advanced Aero-Engine, Beihang University, Beijing 100191 (China); Sun, X.Y. [LMP, Ecole Centrale de Pékin, Beihang University, Beijing 100191 (China); Liu, Y.W., E-mail: liuyangwei@126.com [National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics, School of Energy and Power Engineering, Beihang University, Beijing 100191 (China); Co-Innovation Center for Advanced Aero-Engine, Beihang University, Beijing 100191 (China)

2016-12-09

In order to shed light on understanding the subgrid-scale (SGS) modelling methodology, we analyze and define the concepts of assumption and restriction in the modelling procedure, then show by a generalized derivation that if there are multiple stationary restrictions in a modelling, the corresponding assumption function must satisfy a criterion of orthogonality. Numerical tests using one-dimensional nonlinear advection equation are performed to validate this criterion. This study is expected to inspire future research on generally guiding the SGS modelling methodology. - Highlights: • The concepts of assumption and restriction in the SGS modelling procedure are defined. • A criterion of orthogonality on the assumption and restrictions is derived. • Numerical tests using one-dimensional nonlinear advection equation are performed to validate this criterion.

A uniqueness criterion for the Fock quantization of scalar fields with time-dependent mass

International Nuclear Information System (INIS)

Cortez, Jeronimo; Mena Marugan, Guillermo A; Olmedo, Javier; Velhinho, Jose M

2011-01-01

A major problem in the quantization of fields in curved spacetimes is the ambiguity in the choice of a Fock representation for the canonical commutation relations. There exists infinite number of choices leading to different physical predictions. In stationary scenarios, a common strategy is to select a vacuum (or a family of unitarily equivalent vacua) by requiring invariance under the spacetime symmetries. When stationarity is lost, a natural generalization consists in replacing time invariance by unitarity in the evolution. We prove that when the spatial sections are compact, the criterion of a unitary dynamics, together with the invariance under the spatial isometries, suffices to select a unique family of Fock quantizations for a scalar field with time-dependent mass. (fast track communication)

UNDERSTANDING STUDENT ENGAGEMENT WITH SCHOOL: A LITERATURE REVIEW

Directory of Open Access Journals (Sweden)

Viorel ROBU

2014-11-01

Full Text Available In recent years, there has been an increasing amount of literature on student engagement with school. There is a large agreement on the predictive role that individual differences in student engagement with school plays in relation to a wide range of educational outcomes and to general adjustment. Numerous empirical studies have attempted to explain how individual characteristics of students (e.g., gender, academic motivation, school-related self-efficacy etc., family environment (e.g., parent social support, aspirations of parents concerning the adolescents’ school trajectory or quality of adolescent-parents relationship, and the school/classroom climate (e.g., social support from teachers and peers, autonomy granted to students, quality of instructional practices etc. impact student engagement with school and the academic achievement/performance. This paper summarizes the existing literature on antecedents and positive outcomes of student engagement with school. The implications for educational practice and policy makers are discussed.

Development of a brittle fracture acceptance criterion for the International Atomic Energy Agency (IAEA)

International Nuclear Information System (INIS)

Sorenson, K.B.; Salzbrenner, R.; Nickell, R.E.

1992-01-01

An effort has been undertaken to develop a brittle fracture acceptance criterion for structural components of nuclear material transportation casks. The need for such a criterion was twofold. First, new generation cask designs have proposed the use of ferritic steels and other materials to replace the austenitic stainless steel commonly used for structural components in transport casks. Unlike austenitic stainless steel which fails in a high-energy absorbing, ductile tearing mode, it is possible for these candidate materials to fail via brittle fracture when subjected to certain combinations of elevated loading rates and low temperatures. Second, there is no established brittle fracture criterion accepted by the regulatory community that covers a broad range of structural materials. Although the existing IAEA Safety Series number-sign 37 addressed brittle fracture, its the guidance was dated and pertained only to ferritic steels. Consultant's Services Meetings held under the auspices of the IAEA have resulted in a recommended brittle fracture criterion. The brittle fracture criterion is based on linear elastic fracture mechanics, and is the result of a consensus of experts from six participating IAEA-member countries. The brittle fracture criterion allows three approaches to determine the fracture toughness of the structural material. The three approaches present the opportunity to balance material testing requirements and the conservatism of the material's fracture toughness which must be used to demonstrate resistance to brittle fracture. This work has resulted in a revised Appendix IX to Safety Series number-sign 37 which will be released as an IAEA Technical Document within the coming year

How Do Work Engagement, Workaholism, and the Work-to-Family Interface Affect Each Other? A 7-Year Follow-Up Study.

Science.gov (United States)

Hakanen, Jari; Peeters, Maria

2015-06-01

To investigate the long-term relationships between work engagement, workaholism, work-to-family enrichment, and work-to-family conflict (WFC). We used structural equation modeling and the three-wave 7-year follow-up data of 1580 Finnish dentists to test our hypotheses. Work engagement and work-to-family enrichment mutually predicted each other, and work engagement also negatively predicted WFC. Workaholism predicted WFC, but not vice versa. Work engagement and workaholism were unrelated over time. The results indicate that beyond its suggested benefits for organizations, work engagement may boost the positive interaction between work and family, whereas workaholism is likely to lead to WFC over time. It is valuable for organizations to distinguish work engagement from workaholism and to enhance the former while preventing the latter to have sustainably hardworking working employees with happy home lives.

Systems interaction and single failure criterion

International Nuclear Information System (INIS)

1981-01-01

This report documents the results of a six-month study to evaluate the ongoing research programs of the U.S. Nuclear Regulatory Commission (NRC) and U.S. commercial nuclear station owners which address the safety significance of systems interaction and the regulatory adequacy of the single failure criterion. The evaluation of system interactions provided is the initial phase of a more detailed study leading to the development and application of methodology for quantifying the relative safety of operating nuclear plants. (Auth.)

Short-Cut Estimators of Criterion-Referenced Test Consistency.

Science.gov (United States)

Brown, James Dean

1990-01-01

Presents simplified methods for deriving estimates of the consistency of criterion-referenced, English-as-a-Second-Language tests, including (1) the threshold loss agreement approach using agreement or kappa coefficients, (2) the squared-error loss agreement approach using the phi(lambda) dependability approach, and (3) the domain score…

Failure prediction of low-carbon steel pressure vessel and cylindrical models

International Nuclear Information System (INIS)

Zhang, K.D.; Wang, W.

1987-01-01

The failure loads predicted by failure assessment methods (namely the net-section stress criterion; the EPRI engineering approach for elastic-plastic analysis; the CEGB failure assessment route; the modified R6 curve by Milne for strain hardening; and the failure assessment curve based on J estimation by Ainsworth) have been compared with burst test results on externally, axially sharp notched pressure vessel and open-ended cylinder models made from typical low-carbon steel St45 seamless tube which has a transverse true stress-strain curve of straight-line and parabola type and a high value of ultimate strength to yield. It was concluded from the comparison that whilst the net-section stress criterion and the CEGB route did not give conservative predictions, Milne's modified curve did give a conservative and good prediction; Ainsworth's curve gave a fairly conservative prediction; and EPRI solutions also could conditionally give a good prediction but the conditions are still somewhat uncertain. It is suggested that Milne's modified R6 curve is used in failure assessment of low-carbon steel pressure vessels. (author)

A new criterion of photostimulated luminescence (PSL) method to detect irradiated traditional Chinese medicinal herbs

International Nuclear Information System (INIS)

Zhang, Liwen; Lin, Tong; Jiang, Yingqiao; Bi, Fujun

2013-01-01

This work used a new criterion to analyze 162 varieties (222 batches) of traditional Chinese medicinal herbs based on the European Standard EN 13751 (2009. Foodstuffs—Detection of Irradiated Food Using Photostimulated Luminescence. European Committee for Standardization, Brussels, Belgium). The characteristics of PSL signals are described, and a new criterion is established. Compared to EN 13751, the new criterion uses clearer definition to evaluate instead of the ambiguous descriptions in EN Standard, such as “much greater than” and “within the same order of magnitude”. Moreover, the accuracy of the new criterion is as good as or better than EN Standard in regard to classifying irradiated and non-irradiated traditional Chinese medicinal herbs. It can help to avoid false positive result when a non-irradiated herb got a screening PSL measurement above 5000 counts/60 s. This new criterion of photostimulated luminescence method can be applied to identify the irradiation status of traditional Chinese medicinal herbs, even if the medicinal herbs were irradiated at a low dose (0.3 kGy) or stored in the dark at room temperature for 24 months after the irradiation treatment. - Highlights: • Clearer evaluation criterion instead of the ambiguous descriptions in EN 13751. • Accuracy satisfied. • Large sample size provides outstanding representativeness. • Systematical evaluation on PSL method

Experiments and modeling of ballistic penetration using an energy failure criterion

Directory of Open Access Journals (Sweden)

Dolinski M.

2015-01-01

Full Text Available One of the most intricate problems in terminal ballistics is the physics underlying penetration and perforation. Several penetration modes are well identified, such as petalling, plugging, spall failure and fragmentation (Sedgwick, 1968. In most cases, the final target failure will combine those modes. Some of the failure modes can be due to brittle material behavior, but penetration of ductile targets by blunt projectiles, involving plugging in particular, is caused by excessive localized plasticity, with emphasis on adiabatic shear banding (ASB. Among the theories regarding the onset of ASB, new evidence was recently brought by Rittel et al. (2006, according to whom shear bands initiate as a result of dynamic recrystallization (DRX, a local softening mechanism driven by the stored energy of cold work. As such, ASB formation results from microstructural transformations, rather than from thermal softening. In our previous work (Dolinski et al., 2010, a failure criterion based on plastic strain energy density was presented and applied to model four different classical examples of dynamic failure involving ASB formation. According to this criterion, a material point starts to fail when the total plastic strain energy density reaches a critical value. Thereafter, the strength of the element decreases gradually to zero to mimic the actual material mechanical behavior. The goal of this paper is to present a new combined experimental-numerical study of ballistic penetration and perforation, using the above-mentioned failure criterion. Careful experiments are carried out using a single combination of AISI 4340 FSP projectiles and 25[mm] thick RHA steel plates, while the impact velocity, and hence the imparted damage, are systematically varied. We show that our failure model, which includes only one adjustable parameter in this present work, can faithfully reproduce each of the experiments without any further adjustment. Moreover, it is shown that the

Statistical criterion for Bubbly-slug flow transition

Energy Technology Data Exchange (ETDEWEB)

Zigler, J; Elias, E [Technion-Israel Inst. of Tech., Haifa (Israel). Dept. of Mechanical Engineering

1996-12-01

The investigation of flow pattern transitions is still an interesting problem in the research of multiphase Row. It has been studied theoretically, and experimental confirmation of the models has been found by many investigators. The present paper deals with a statistical approach to bubbly-slug transitions in a vertical upward two phase flow and a new transition criterion is deduced from experimental data (authors).

A new risk-based screening criterion for treatment-demanding retinopathy of prematurity in Denmark

DEFF Research Database (Denmark)

Slidsborg, Carina; Forman, Julie Lyng; Rasmussen, Steen Christian

2011-01-01

The aim of this study was to uncover the most effective and safe criterion to implement for retinopathy of prematurity screening in Denmark.......The aim of this study was to uncover the most effective and safe criterion to implement for retinopathy of prematurity screening in Denmark....

Energy-efficient induction motors designing with application of a modified criterion of reduced costs

Directory of Open Access Journals (Sweden)

V.S. Petrushin

2014-03-01

Full Text Available The paper introduces a modified criterion of reduced costs that employs coefficients of operation significance and priority of ohmic loss accounting to allow matching maximum efficiency with minimum reduced costs. Impact of the inflation factor on the criterion of reduced costs is analyzed.

Elaboration of generalized criterion for zonality determination of the Chernobyl' NPP working spaces

International Nuclear Information System (INIS)

Simakov, A.V.; Bad'in, V.I.; Nosovskij, A.V.

1992-01-01

Analysis of the features of radioactive dose rating, regularities of their formation and dosimetry allows suggesting generalized criterion for assess zonality of compartments and territories, combining all factors and their action on operators. This criterion may be used during design of the new objects, development of programs and pursuance of work on removal of atomic power plants from operation. 6 refs.; 1 fig

Synchronization criterion for Lur'e type complex dynamical networks with time-varying delay

International Nuclear Information System (INIS)

Ji, D.H.; Park, Ju H.; Yoo, W.J.; Won, S.C.; Lee, S.M.

2010-01-01

In this Letter, the synchronization problem for a class of complex dynamical networks in which every identical node is a Lur'e system with time-varying delay is considered. A delay-dependent synchronization criterion is derived for the synchronization of complex dynamical network that represented by Lur'e system with sector restricted nonlinearities. The derived criterion is a sufficient condition for absolute stability of error dynamics between the each nodes and the isolated node. Using a convex representation of the nonlinearity for error dynamics, the stability condition based on the discretized Lyapunov-Krasovskii functional is obtained via LMI formulation. The proposed delay-dependent synchronization criterion is less conservative than the existing ones. The effectiveness of our work is verified through numerical examples.

Jeans' criterion and nonextensive velocity distribution function in kinetic theory

International Nuclear Information System (INIS)

Du Jiulin

2004-01-01

The effect of nonextensivity of self-gravitating systems on the Jeans' criterion for gravitational instability is studied in the framework of Tsallis statistics. The nonextensivity is introduced in the Jeans problem by a generalized q-nonextensive velocity distribution function through the equation of state of ideal gas in nonextensive kinetic theory. A new Jeans' criterion is deduced with a factor √(2/(5-3q)) that, however, differs from that one in [Astron. Astrophys. 396 (2002) 309] and new results of gravitational instability are analyzed for the nonextensive parameter q. An understanding of physical meaning of q and a possible seismic observation to find astronomical evidence for a value of q different from unity are also discussed

Establishment of an equivalence acceptance criterion for accelerated stability studies.

Science.gov (United States)

Burdick, Richard K; Sidor, Leslie

2013-01-01

In this article, the use of statistical equivalence testing for providing evidence of process comparability in an accelerated stability study is advocated over the use of a test of differences. The objective of such a study is to demonstrate comparability by showing that the stability profiles under nonrecommended storage conditions of two processes are equivalent. Because it is difficult at accelerated conditions to find a direct link to product specifications, and hence product safety and efficacy, an equivalence acceptance criterion is proposed that is based on the statistical concept of effect size. As with all statistical tests of equivalence, it is important to collect input from appropriate subject-matter experts when defining the acceptance criterion.

Fracture criterion for brittle materials based on statistical cells of finite volume

International Nuclear Information System (INIS)

Cords, H.; Kleist, G.; Zimmermann, R.

1986-06-01

An analytical consideration of the Weibull Statistical Analysis of brittle materials established the necessity of including one additional material constant for a more comprehensive description of the failure behaviour. The Weibull analysis is restricted to infinitesimal volume elements in consequence of the differential calculus applied. It was found that infinitesimally small elements are in conflict with the basic statistical assumption and that the differential calculus is not needed in fact since nowadays most of the stress analyses are based on finite element calculations, and these are most suitable for a subsequent statistical analysis of strength. The size of a finite statistical cell has been introduced as the third material parameter. It should represent the minimum volume containing all statistical features of the material such as distribution of pores, flaws and grains. The new approach also contains a unique treatment of failure under multiaxial stresses. The quantity responsible for failure under multiaxial stresses is introduced as a modified strain energy. Sixteen different tensile specimens including CT-specimens have been investigated experimentally and analyzed with the probabilistic fracture criterion. As a result it can be stated that the failure rates of all types of specimens made from three different grades of graphite are predictable. The accuracy of the prediction is one standard deviation. (orig.) [de

Implicit Social Cognitions Predict Sex Differences in Math Engagement and Achievement

Science.gov (United States)

Nosek, Brian A.; Smyth, Frederick L.

2011-01-01

Gender stereotypes about math and science do not need to be endorsed, or even available to conscious introspection, to contribute to the sex gap in engagement and achievement in science, technology, engineering, and mathematics (STEM). The authors examined implicit math attitudes and stereotypes among a heterogeneous sample of 5,139 participants.…

When does spiritual intelligence particularly predict job engagement? The mediating role of psychological empowerment

OpenAIRE

Mohsen Torabi; Iman Zohoorian Nadali

2016-01-01

Background: Regarding the importance of health care providers such as nurses who are always in stressful environments, it is imperative to better understand how they become more engaged in their work. The purpose of this paper is to focus on health care providers (nurses), and examine how the interaction between spiritual intelligence and psychological empowerment affect job engagement. Materials and Methods: This descriptive and quantitative study was conducted among nurses at the Faghihi Ho...

No rationale for 1 variable per 10 events criterion for binary logistic regression analysis

Directory of Open Access Journals (Sweden)

Maarten van Smeden

2016-11-01

Full Text Available Abstract Background Ten events per variable (EPV is a widely advocated minimal criterion for sample size considerations in logistic regression analysis. Of three previous simulation studies that examined this minimal EPV criterion only one supports the use of a minimum of 10 EPV. In this paper, we examine the reasons for substantial differences between these extensive simulation studies. Methods The current study uses Monte Carlo simulations to evaluate small sample bias, coverage of confidence intervals and mean square error of logit coefficients. Logistic regression models fitted by maximum likelihood and a modified estimation procedure, known as Firth’s correction, are compared. Results The results show that besides EPV, the problems associated with low EPV depend on other factors such as the total sample size. It is also demonstrated that simulation results can be dominated by even a few simulated data sets for which the prediction of the outcome by the covariates is perfect (‘separation’. We reveal that different approaches for identifying and handling separation leads to substantially different simulation results. We further show that Firth’s correction can be used to improve the accuracy of regression coefficients and alleviate the problems associated with separation. Conclusions The current evidence supporting EPV rules for binary logistic regression is weak. Given our findings, there is an urgent need for new research to provide guidance for supporting sample size considerations for binary logistic regression analysis.

The comparison of predictive scheduling algorithms for different sizes of job shop scheduling problems

Science.gov (United States)

Paprocka, I.; Kempa, W. M.; Grabowik, C.; Kalinowski, K.; Krenczyk, D.

2016-08-01

In the paper a survey of predictive and reactive scheduling methods is done in order to evaluate how the ability of prediction of reliability characteristics influences over robustness criteria. The most important reliability characteristics are: Mean Time to Failure, Mean Time of Repair. Survey analysis is done for a job shop scheduling problem. The paper answers the question: what method generates robust schedules in the case of a bottleneck failure occurrence before, at the beginning of planned maintenance actions or after planned maintenance actions? Efficiency of predictive schedules is evaluated using criteria: makespan, total tardiness, flow time, idle time. Efficiency of reactive schedules is evaluated using: solution robustness criterion and quality robustness criterion. This paper is the continuation of the research conducted in the paper [1], where the survey of predictive and reactive scheduling methods is done only for small size scheduling problems.

Predictive control and identification: Applications to steering dynamics

DEFF Research Database (Denmark)

Hansen, Anca Daniela

1996-01-01

and of the loss function, which defines the optimality of the control. Some guidelines on how to choose the design parameters, depending on the type of process to be controlled and on the required control performance, are presented. A predictive track keeping system for a Mariner Class Vessel is formulated based...... the under- standing of the connection between identification and control, analysed in Chapter 7. Chapter 7 focuses on how to make the on-line identification for predictive control more robust towards unmodelled dynamics. The theory is verified via simulation studies on a Mariner Class Vessel. The effects...... and the need of a prefilter in the estimation are analysed and illustrated. Based on the idea that the control criterion must be dual to the estimation criterion, an iterative optimal prefilter is designed. This seems to be an appealing way to tune the model towards the objective for which the model...

Specific strain work as a failure criterion in plane stress state

International Nuclear Information System (INIS)

Zuchowski, R.; Zietkowski, L.

1985-01-01

An experimental verification of failure criterion based on specific strain work was performed. Thin-walled cylindrical specimens were examined by loading with constant force and constant torque moment, assuming different values for particular tests, at the same time keeping stress intensity constant, and by subjecting to thermal cycling. It was found that the critical value of failure did not depend on axial-to-shearing stresses ratio, i.e., on the type of state of stress. Thereby, the validity of the analysed failure criterion in plane stress was confirmed. Besides, a simple description of damage development in plane stress was suggested. (orig./RF)

An analytic expression for the sheath criterion in magnetized plasmas with multi-charged ion species

International Nuclear Information System (INIS)

Hatami, M. M.

2015-01-01

The generalized Bohm criterion in magnetized multi-component plasmas consisting of multi-charged positive and negative ion species and electrons is analytically investigated by using the hydrodynamic model. It is assumed that the electrons and negative ion density distributions are the Boltzmann distribution with different temperatures and the positive ions enter into the sheath region obliquely. Our results show that the positive and negative ion temperatures, the orientation of the applied magnetic field and the charge number of positive and negative ions strongly affect the Bohm criterion in these multi-component plasmas. To determine the validity of our derived generalized Bohm criterion, it reduced to some familiar physical condition and it is shown that monotonically reduction of the positive ion density distribution leading to the sheath formation occurs only when entrance velocity of ion into the sheath satisfies the obtained Bohm criterion. Also, as a practical application of the obtained Bohm criterion, effects of the ionic temperature and concentration as well as magnetic field on the behavior of the charged particle density distributions and so the sheath thickness of a magnetized plasma consisting of electrons and singly charged positive and negative ion species are studied numerically

The Cost of Materialism in a Collectivistic Culture: Predicting Risky Behavior Engagement in Chinese Adolescents

Science.gov (United States)

Auerbach, Randy P.; McWhinnie, Chad M.; Goldfinger, Marc; Abela, John R. Z.; Zhu, Xiongzhao; Yao, Shuqiao

2010-01-01

The goals of the current study were to examine whether (a) negative events mediate the relationship between materialism and risky behavior engagement and (b) materialism moderates the relationship between stress and engagement in risky behaviors in Chinese youth. At Time 1, 406 adolescents (ages 14-19) from Yue Yang, China, completed measures…

Student Engagement

DEFF Research Database (Denmark)

Conduit, Jodie; Karpen, Ingo; Farrelly, Francis

2017-01-01

system (the university), the narrow service system (the course), and the individual dyadic level of engagement (the student-lecturer interaction). These findings could be further considered and empirically tested in other engagement contexts (e.g. employee engagement, customer engagement).......Universities are seeking to actively and strategically manage student engagement through providing opportunities for students to interact and engage with the institution on a range of levels and in different ways. However, this increasingly complex and multi-layered nature of student engagement...... within a tertiary education environment is not well understood. Through qualitative focus groups and a series of interviews with undergraduate and postgraduate students, this study explores and articulates the cognitive, emotional, behavioural and social dimensions of engagement that depict the nature...

Integral criterion for selecting nonlinear crystals for frequency conversion

International Nuclear Information System (INIS)

Grechin, Sergei G

2009-01-01

An integral criterion, which takes into account all parameters determining the conversion efficiency, is offered for selecting nonlinear crystals for frequency conversion. The angular phase-matching width is shown to be related to the beam walk-off angle. (nonlinear optical phenomena)

Satisfying the Einstein-Podolsky-Rosen criterion with massive particles

DEFF Research Database (Denmark)

Peise, Jan; Kruse, I.; Lange, K.

2016-01-01

In 1935, Einstein, Podolsky and Rosen (EPR) questioned the completeness of quantum mechanics by devising a quantum state of two massive particles with maximally correlated space and momentum coordinates. The EPR criterion qualifies such continuous-variable entangled states, as shown successfully...

Infants’ Early Visual Attention and Social Engagement as Developmental Precursors to Joint Attention

Science.gov (United States)

Salley, Brenda; Sheinkopf, Stephen J.; Neal-Beevers, A. Rebecca; Tenenbaum, Elena J.; Miller-Loncar, Cynthia L.; Tronick, Ed; Lagasse, Linda L.; Shankaran, Seetha; Bada, Henrietta; Bauer, Charles; Whitaker, Toni; Hammond, Jane; Lester, Barry M.

2016-01-01

This study examined infants’ early visual attention (at 1 month of age) and social engagement (4 months) as predictors of their later joint attention (12 and 18 months). The sample (n=325), drawn from the Maternal Lifestyle Study, a longitudinal multicenter project conducted at four centers of the NICHD Neonatal Research Network, included high-risk (cocaine exposed) and matched non-cocaine exposed infants. Hierarchical regressions revealed that infants’ attention orienting at 1 month significantly predicted more frequent initiating joint attention at 12 (but not 18) months of age. Social engagement at 4 months predicted initiating joint attention at 18 months. Results provide the first empirical evidence for the role of visual attention and social engagement behaviors as developmental precursors for later joint attention outcome. PMID:27786527

The influence of organisational rewards on workplace trust and work engagement

Directory of Open Access Journals (Sweden)

Janine Victor

2017-05-01

Full Text Available Orientation: In volatile and competitive business environments, organisations are faced with challenges to retain talented workers. Employees are increasingly leaving their jobs for a number of reasons, one of them being a perceived lack of adequate reward practices. Consequently, this has impacted on employee work engagement and confidence and trust in organisations. Research purpose: The study sought to determine whether there is a relationship between rewards, trust and engagement, as well as whether rewards are able to predict trust and engagement in the South African workplace. Motivation for the study: Organisations can no longer solely rely on extrinsic rewards to retain talent. Companies must draw on both extrinsic and intrinsic reward strategies to improve retention levels through endorsing higher levels of workplace trust and work engagement levels. Research design, approach and method: A quantitative, exploratory and cross-sectional research design was utilised. Non-probability sampling using questionnaires consisting of scales from the Job Satisfaction Survey, Intrinsic Motivation Inventory, Psychological Meaningfulness Scale, Basic Needs at Work Scale, Workplace Trust Survey and Utrecht Work Engagement Scale were administered to a sample (N = 251 of South African employees in various industries within the Gauteng region. Main findings: Results indicated that there is a moderate-to-strong positive relationship between the three constructs, and that rewards are able to predict trust and engagement. Practical and managerial implications: The findings provide insight for behavioural practitioners to potentially draw upon when improving talent management strategies. Both extrinsic and intrinsic rewards are important factors in keeping employees engaged and ultimately retaining them. Contribution: The study provided insight into the influence that organisational rewards may have on workplace trust, work engagement and retaining employees

Work Demands-Burnout and Job Engagement-Job Satisfaction Relationships: Teamwork as a Mediator and Moderator.

Science.gov (United States)

Mijakoski, Dragan; Karadzinska-Bislimovska, Jovanka; Basarovska, Vera; Minov, Jordan; Stoleski, Sasho; Angeleska, Nada; Atanasovska, Aneta

2015-03-15

Few studies have examined teamwork as mediator and moderator of work demands-burnout and job engagement-job satisfaction relationships in healthcare workers (HCWs) in South-East Europe. To assess mediation and moderation effect of teamwork on the relationship between independent (work demands or job engagement) and dependent (burnout or job satisfaction) variables. Work demands, burnout, job engagement, and job satisfaction were measured with Hospital Experience Scale, Maslach Burnout Inventory, Utrecht Work Engagement Scale, and Job Satisfaction Survey, respectively. Hospital Survey on Patient Safety Culture was used for assessment of teamwork. In order to examine role of teamwork as a mediating variable we fit series of regression models for burnout and job satisfaction. We also fit regression models predicting outcome (burnout or job satisfaction) from predictor (work demands or job engagement) and moderator (teamwork) variable. Teamwork was partial mediator of work demands-burnout relationship and full mediator of job engagement-job satisfaction relationship. We found that only job engagement-job satisfaction relationship was moderated by teamwork. Occupational health services should target detection of burnout in HCWs and implementation of organizational interventions in hospitals, taking into account findings that teamwork predicted reduced burnout and higher job satisfaction.

Optimal order and time-step criterion for Aarseth-type N-body integrators

International Nuclear Information System (INIS)

Makino, Junichiro

1991-01-01

How the selection of the time-step criterion and the order of the integrator change the efficiency of Aarseth-type N-body integrators is discussed. An alternative to Aarseth's scheme based on the direct calculation of the time derivative of the force using the Hermite interpolation is compared to Aarseth's scheme, which uses the Newton interpolation to construct the predictor and corrector. How the number of particles in the system changes the behavior of integrators is examined. The Hermite scheme allows a time step twice as large as that for the standard Aarseth scheme for the same accuracy. The calculation cost of the Hermite scheme per time step is roughly twice as much as that of the standard Aarseth scheme. The optimal order of the integrators depends on both the particle number and the accuracy required. The time-step criterion of the standard Aarseth scheme is found to be inapplicable to higher-order integrators, and a more uniformly reliable criterion is proposed. 18 refs

Job shop scheduling problem with late work criterion

Science.gov (United States)

Piroozfard, Hamed; Wong, Kuan Yew

2015-05-01

Scheduling is considered as a key task in many industries, such as project based scheduling, crew scheduling, flight scheduling, machine scheduling, etc. In the machine scheduling area, the job shop scheduling problems are considered to be important and highly complex, in which they are characterized as NP-hard. The job shop scheduling problems with late work criterion and non-preemptive jobs are addressed in this paper. Late work criterion is a fairly new objective function. It is a qualitative measure and concerns with late parts of the jobs, unlike classical objective functions that are quantitative measures. In this work, simulated annealing was presented to solve the scheduling problem. In addition, operation based representation was used to encode the solution, and a neighbourhood search structure was employed to search for the new solutions. The case studies are Lawrence instances that were taken from the Operations Research Library. Computational results of this probabilistic meta-heuristic algorithm were compared with a conventional genetic algorithm, and a conclusion was made based on the algorithm and problem.

Rational for the use of children's motor activity as a criterion for the effectiveness of rehabilitation and recreation

Directory of Open Access Journals (Sweden)

A.G. Platonova

2013-11-01

Full Text Available Purpose – justified the use of physical activity for children as a criterion for recreation. Studied the relationship of this index with morphological and functional features of development and the level of hygiene knowledge. The study involved 54 pupils aged 10-14 years. Results: It is shown that the level of physical activity (1282,37 ± 289,20 locomotion per day. The value of basal metabolism reaches (1350,51 ± 33,69 kcal. Established direct correlation with the main motor activity exchange (r = 0,81; body weight (r = 0,80; circumference of the chest in the pause / inspiratory / expiratory (r = 0,70-0,71; vital capacity (r = 0,37; hand muscular strength (r = 0,51-0,58. The estimation of the physical development of children by Quetelet index: mass deficit is set at 12.96%, 29.63% obese, normal physical development at 51.85% overweight at 5.56%. Conclusions: The recommended value of physical activity as a criterion for recreation and health of school children. Its definition reflects the functional state of the school, as one of the criteria for defining the health, predicts its changes, which is especially valuable in monitoring.

A Deeper Understanding of Stability in the Solar Wind: Applying Nyquist's Instability Criterion to Wind Faraday Cup Data

Science.gov (United States)

Alterman, B. L.; Klein, K. G.; Verscharen, D.; Stevens, M. L.; Kasper, J. C.

2017-12-01

Long duration, in situ data sets enable large-scale statistical analysis of free-energy-driven instabilities in the solar wind. The plasma beta and temperature anisotropy plane provides a well-defined parameter space in which a single-fluid plasma's stability can be represented. Because this reduced parameter space can only represent instability thresholds due to the free energy of one ion species - typically the bulk protons - the true impact of instabilities on the solar wind is under estimated. Nyquist's instability criterion allows us to systematically account for other sources of free energy including beams, drifts, and additional temperature anisotropies. Utilizing over 20 years of Wind Faraday cup and magnetic field observations, we have resolved the bulk parameters for three ion populations: the bulk protons, beam protons, and alpha particles. Applying Nyquist's criterion, we calculate the number of linearly growing modes supported by each spectrum and provide a more nuanced consideration of solar wind stability. Using collisional age measurements, we predict the stability of the solar wind close to the sun. Accounting for the free-energy from the three most common ion populations in the solar wind, our approach provides a more complete characterization of solar wind stability.

Work engagement, social support, and job satisfaction in Portuguese nursing staff: A winning combination.

Science.gov (United States)

Orgambídez-Ramos, Alejandro; de Almeida, Helena

2017-08-01

Job Demands-Resources model assumes the mediator role of work engagement between social support (job resource) and job satisfaction (organizational result). However, recent studies suggest that social support can be considered as a moderator variable in the relationship between engagement and job satisfaction in nursing staff. The aim of this study is to analyze the moderator role of social support, from supervisor and from co-workers, in the relationship between work engagement and job satisfaction in a Portuguese nursing sample. We conducted a cross-sectional and correlational study assessing a final sample of 215 participants (55.56% response rate, 77.21% women). Moderation analyses were carried out using multiple and hierarchical linear regression models. Job satisfaction was significantly predicted by work engagement and social support from supervisor and from co-workers. The significant interaction in predicting job satisfaction showed that social support from co-workers enhances the effects of work engagement on nurses' satisfaction. A climate of social support among co-workers and higher levels of work engagement have a positive effect on job satisfaction, improving quality care and reducing turnover intention in nursing staff. Copyright © 2017 Elsevier Inc. All rights reserved.

Workaholism vs. work engagement: the two different predictors of future well-being and performance.

Science.gov (United States)

Shimazu, Akihito; Schaufeli, Wilmar B; Kamiyama, Kimika; Kawakami, Norito

2015-02-01

This study investigated the distinctiveness of two types of heavy work investment (i.e., workaholism and work engagement) by examining their 2-year longitudinal relationships with employee well-being and job performance. Based on a previous cross-sectional study by Shimazu and Schaufeli (Ind Health 47:495-502, 2009) and a shorter term longitudinal study by Shimazu et al. (Ind Health 50:316-21, 2012; measurement interval = 7 months), we predicted that workaholism predicts long-term future unwell-being (i.e., high ill-health and low life satisfaction) and poor job performance, whereas work engagement predicts future well-being (i.e., low ill-health and high life satisfaction) and superior job performance. A two-wave survey was conducted among employees from one Japanese company, and valid data from 1,196 employees was analyzed using structural equation modeling. T1-T2 changes in ill-health, life satisfaction, and job performance were measured as residual scores, which were included in the structural equation model. Workaholism and work engagement were weakly and positively related to each other. In addition, and as expected, workaholism was related to an increase in ill-health and to a decrease in life satisfaction. In contrast, and also as expected, work engagement was related to increases in both life satisfaction and job performance and to a decrease in ill-health. Although workaholism and work engagement are weakly positively related, they constitute two different concepts. More specifically, workaholism has negative consequences across an extended period of 2 years, whereas work engagement has positive consequences in terms of well-being and performance. Hence, workaholism should be prevented and work engagement should be stimulated.

Prediction of desulfurization in torpedo gas from laboratory scale simulation; Previsao da dessulfuracao do gusa em carro-torpedo a partir de simulacoes em escala de laboratorio

Energy Technology Data Exchange (ETDEWEB)

Souza Costa, Sergio L. de [USIMINAS, Ipatinga, MG (Brazil). Centro de Pesquisa e Desenvolvimento; Figueira, Renato M. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Escola de Engenharia

1996-12-31

A general criterion for laboratory scale data transposing to industrial practice, based on Navier-Stokes equation is developed. The criterion is a dimensional relation between the rate of energy dissipation, dimensions such as the height and diameter of the reactor and the inertial forces. The criterion was used to predict the evolution of the pig iron desulfurization reaction in torpedo car from results obtained in laboratory scale. The agreement between values predicted from laboratory experiments and data generated from actual industrial desulfurization operation is excellent. (author) 10 refs., 5 figs., 7 tabs.

Logical and Decisive Combining Criterion for Binary Group Decision Making

Directory of Open Access Journals (Sweden)

Ivan Vrana

2010-04-01

Full Text Available A new combining criterion, the Multiplicative Proportional Deviative Influence (MPDI is presented for combining or aggregating multi-expert numerical judgments in Yes-or-No type ill-structured group decision making situations. This newly proposed criterion performs well in comparison with the widely used aggregation means: the Arithmetic Mean (AM, and Geometric Mean (GM, especially in better reflecting the degree of agreement between criteria levels or numerical experts’ judgments. The MPDI can be considered as another class of combining criteria that make effect of the degree of agreement among multiple numerical judgments. The MPDI is applicable in integrating several collaborative or synergistic decision making systems through combining final numerical decision outputs. A discussion and generalization of the proposed MPDI is discussed withnumerical example.

Effect of plastic strain on elastic-plastic fracture toughness of SM490 carbon steel. Assessment by stress-based criterion for ductile crack initiation

International Nuclear Information System (INIS)

Kamaya, Masayuki

2012-01-01

Although the plastic strain induced in materials increases the mechanical strength, it may reduce the fracture toughness. In this study, the change in fracture toughness of SM490 carbon steel due to pre-straining was investigated using a stress-based criterion for ductile crack initiation. The specimens with blunt notch of various radiuses were used in addition to those with conventional fatigue pre-cracking. The degree of applied plastic strain was 5%, 10% or 20%. The fracture toughness was largest when the induced plastic strain was 5%, although it decreased for the plastic strains of 10% and 20%. The stress and strain distributions near the crack tip of fracture toughness test specimens was investigated by elastic-plastic finite element analyses using a well-correlated stress-strain curve for large strain. It was shown that the critical condition at the onset of the ductile crack was better correlated with the equivalent stress than the plastic strain at the crack tip. By using the stress-based criterion, which was represented by the equivalent stress and stress triaxiality, the change in the fracture toughness due to pre-straining could be reasonably explained. Based on these results, it was concluded that the stress-based criterion should be used for predicting the ductile crack initiation. (author)

Mass spectrometric confirmation criterion for product-ion spectra generated in flow-injection analysis. Environmental application

NARCIS (Netherlands)

Geerdink, R.B.; Niessen, W.M.A.; Brinkman, U.A.T.

2001-01-01

The suitability of a confirmation criterion recently recommended in the Netherlands for gas chromatography with mass spectrometric detection (GC-MS), was evaluated for flow-injection analysis (FIA) with atmospheric pressure chemical ionisation MS-MS detection. The main feature of the criterion is

National Guard Engagement in the Pacific: No Threat to Security

National Research Council Canada - National Science Library

Bour, Mark

2002-01-01

... there. It predicts likely responses from non-participants and defends the program against critics who argue that engagement activities draw personnel and resources away from primary war fighting objectives...

Multi-Criterion Two-Sided Matching of Public–Private Partnership Infrastructure Projects: Criteria and Methods

Directory of Open Access Journals (Sweden)

Ru Liang

2018-04-01

Full Text Available Two kinds of evaluative criteria are associated with Public–Private Partnership (PPP infrastructure projects, i.e., private evaluative criteria and public evaluative criteria. These evaluative criteria are inversely related, that is, the higher the public benefits; the lower the private surplus. To balance evaluative criteria in the Two-Sided Matching (TSM decision, this paper develops a quantitative matching decision model to select an optimal matching scheme for PPP infrastructure projects based on the Hesitant Fuzzy Set (HFS under unknown evaluative criterion weights. In the model, HFS is introduced to describe values of the evaluative criteria and multi-criterion information is fully considered given by groups. The optimal model is built and solved by maximizing the whole deviation of each criterion so that the evaluative criterion weights are determined objectively. Then, the match-degree of the two sides is calculated and a multi-objective optimization model is introduced to select an optimal matching scheme via a min-max approach. The results provide new insights and implications of the influence on evaluative criteria in the TSM decision.

Entanglement in SU(2)-invariant quantum systems: The positive partial transpose criterion and others

International Nuclear Information System (INIS)

Schliemann, John

2005-01-01

We study entanglement in mixed bipartite quantum states which are invariant under simultaneous SU(2) transformations in both subsystems. Previous results on the behavior of such states under partial transposition are substantially extended. The spectrum of the partial transpose of a given SU(2)-invariant density matrix ρ is entirely determined by the diagonal elements of ρ in a basis of tensor-product states of both spins with respect to a common quantization axis. We construct a set of operators which act as entanglement witnesses on SU(2)-invariant states. A sufficient criterion for ρ having a negative partial transpose is derived in terms of a simple spin correlator. The same condition is a necessary criterion for the partial transpose to have the maximum number of negative eigenvalues. Moreover, we derive a series of sum rules which uniquely determine the eigenvalues of the partial transpose in terms of a system of linear equations. Finally we compare our findings with other entanglement criteria including the reduction criterion, the majorization criterion, and the recently proposed local uncertainty relations

Statistical surrogate model based sampling criterion for stochastic global optimization of problems with constraints

Energy Technology Data Exchange (ETDEWEB)

Cho, Su Gil; Jang, Jun Yong; Kim, Ji Hoon; Lee, Tae Hee [Hanyang University, Seoul (Korea, Republic of); Lee, Min Uk [Romax Technology Ltd., Seoul (Korea, Republic of); Choi, Jong Su; Hong, Sup [Korea Research Institute of Ships and Ocean Engineering, Daejeon (Korea, Republic of)

2015-04-15

Sequential surrogate model-based global optimization algorithms, such as super-EGO, have been developed to increase the efficiency of commonly used global optimization technique as well as to ensure the accuracy of optimization. However, earlier studies have drawbacks because there are three phases in the optimization loop and empirical parameters. We propose a united sampling criterion to simplify the algorithm and to achieve the global optimum of problems with constraints without any empirical parameters. It is able to select the points located in a feasible region with high model uncertainty as well as the points along the boundary of constraint at the lowest objective value. The mean squared error determines which criterion is more dominant among the infill sampling criterion and boundary sampling criterion. Also, the method guarantees the accuracy of the surrogate model because the sample points are not located within extremely small regions like super-EGO. The performance of the proposed method, such as the solvability of a problem, convergence properties, and efficiency, are validated through nonlinear numerical examples with disconnected feasible regions.

Generalized statistical criterion for distinguishing random optical groupings from physical multiple systems

International Nuclear Information System (INIS)

Anosova, Z.P.

1988-01-01

A statistical criterion is proposed for distinguishing between random and physical groupings of stars and galaxies. The criterion is applied to nearby wide multiple stars, triplets of galaxies in the list of Karachentsev, Karachentseva, and Shcherbanovskii, and double galaxies in the list of Dahari, in which the principal components are Seyfert galaxies. Systems that are almost certainly physical, probably physical, probably optical, and almost certainly optical are identified. The limiting difference between the radial velocities of the components of physical multiple galaxies is estimated

Differentiation between Superficial and Deep Lobe Parotid Tumors by Magnetic Resonance Imaging: Usefulness of the Parotid Duct Criterion

Energy Technology Data Exchange (ETDEWEB)

Imaizumi, A.; Kuribayashi, A.; Okochi, K.; Yoshino, N.; Kurabayashi, T. (Oral and Maxillofacial Radiology, Graduate School, Tokyo Medical and Dental Univ., Tokyo (Japan)); Ishii, J. (Maxillofacial Surgery, Graduate School, Tokyo Medical and Dental Univ., Tokyo (Japan)); Sumi, Y. (Division of Oral and Dental Surgery, Dept. of Advanced Medicine, National Center for Geriatrics and Gerontology, Aichi (Japan))

2009-08-15

Background: The location of a parotid tumor affects the choice of surgery, and there is a risk of damaging the facial nerve during surgery. Thus, differentiation between superficial and deep lobe parotid tumors is important for appropriate surgical planning. Purpose: To evaluate the usefulness of using the parotid duct, in addition to the retromandibular vein, for differentiating between superficial and deep lobe parotid tumors on MR images. Material and Methods: Magnetic resonance images of 42 parotid tumors in 40 patients were reviewed to determine whether the tumor was located in the superficial or deep lobe. In each case, the retromandibular vein and the parotid duct were used to locate the tumor. The parotid duct was only used in cases where the tumor and the duct were visualized on the same image. Results: Using the retromandibular vein criterion, 71% of deep lobe and 86% of superficial lobe tumors were correctly diagnosed, providing an accuracy of 81%. However, the accuracy achieved when using the parotid duct criterion was 100%, although it could be applied to only 28 of the 42 cases. Based on these results, we defined the following diagnostic method: the parotid duct criterion is first applied, and for cases in which it cannot be applied, the retromandibular vein criterion is used. The accuracy of this method was 88%, which was better than that achieved using the retromandibular vein criterion alone. Conclusion: The parotid duct criterion is useful for determining the location of parotid tumors. Combining the parotid duct criterion with the retromandibular vein criterion might improve the diagnostic accuracy of parotid tumor location compared to using the latter criterion alone

Differentiation between Superficial and Deep Lobe Parotid Tumors by Magnetic Resonance Imaging: Usefulness of the Parotid Duct Criterion

International Nuclear Information System (INIS)

Imaizumi, A.; Kuribayashi, A.; Okochi, K.; Yoshino, N.; Kurabayashi, T.; Ishii, J.; Sumi, Y.

2009-01-01

Background: The location of a parotid tumor affects the choice of surgery, and there is a risk of damaging the facial nerve during surgery. Thus, differentiation between superficial and deep lobe parotid tumors is important for appropriate surgical planning. Purpose: To evaluate the usefulness of using the parotid duct, in addition to the retromandibular vein, for differentiating between superficial and deep lobe parotid tumors on MR images. Material and Methods: Magnetic resonance images of 42 parotid tumors in 40 patients were reviewed to determine whether the tumor was located in the superficial or deep lobe. In each case, the retromandibular vein and the parotid duct were used to locate the tumor. The parotid duct was only used in cases where the tumor and the duct were visualized on the same image. Results: Using the retromandibular vein criterion, 71% of deep lobe and 86% of superficial lobe tumors were correctly diagnosed, providing an accuracy of 81%. However, the accuracy achieved when using the parotid duct criterion was 100%, although it could be applied to only 28 of the 42 cases. Based on these results, we defined the following diagnostic method: the parotid duct criterion is first applied, and for cases in which it cannot be applied, the retromandibular vein criterion is used. The accuracy of this method was 88%, which was better than that achieved using the retromandibular vein criterion alone. Conclusion: The parotid duct criterion is useful for determining the location of parotid tumors. Combining the parotid duct criterion with the retromandibular vein criterion might improve the diagnostic accuracy of parotid tumor location compared to using the latter criterion alone

Staying Engaged: Knowledge and Research Needs in Student Engagement

Science.gov (United States)

Wang, Ming-Te; Degol, Jessica

2016-01-01

In this article, we review knowledge about student engagement and look ahead to the future of study in this area. We begin by describing how researchers in the field define and study student engagement. In particular, we describe the levels, contexts, and dimensions that constitute the measurement of engagement, summarize the contexts that shape engagement and the outcomes that result from it, and articulate person-centered approaches for analyzing engagement. We conclude by addressing limitations to the research and providing recommendations for study. Specifically, we point to the importance of incorporating more work on how learning-related emotions, personality characteristics, prior learning experiences, shared values across contexts, and engagement in nonacademic activities influence individual differences in student engagement. We also stress the need to improve our understanding of the nuances involved in developing engagement over time by incorporating more extensive longitudinal analyses, intervention trials, research on affective neuroscience, and interactions among levels and dimensions of engagement. PMID:27087833

Functional Quality Criterion of Rock Handling Mechanization at Open-pit Mines

Directory of Open Access Journals (Sweden)

Voronov Yuri

2017-01-01

Full Text Available Overburden and mining operations at open-pit mines are performed mainly by powerful shovel-truck systems (STSs. One of the main problems of the STSs is a rather low level of their operating quality, mainly due to unjustified over-trucking. In this article, a functional criterion for assessing the qualify of the STS operation at open-pit mines is formulated, derived and analyzed. We introduce the rationale and general principles for the functional criterion formation, its general form, as well as variations for various STS structures: a mixed truck fleet and a homogeneous shovel fleet, a mixed shove! fleet and a homogeneous truck fleet, mixed truck and shovel fleets. The possibility of assessing the quality of the STS operation is of great importance for identifying the main directions for improving their operational performance and operating quality, optimizing the main performance indicators by the qualify criterion, and. as a result, for possible saving of material and technical resources for open-pit mining. Improvement of the quality of the STS operation also allows increasing the mining safety and decreasing the atmosphere pollution - by means of possible reducing of the number of the operating trucks.

Functional Quality Criterion of Rock Handling Mechanization at Open-pit Mines

Science.gov (United States)

Voronov, Yuri; Voronov, Artyoni

2017-11-01

Overburden and mining operations at open-pit mines are performed mainly by powerful shovel-truck systems (STSs). One of the main problems of the STSs is a rather low level of their operating quality, mainly due to unjustified over-trucking. In this article, a functional criterion for assessing the qualify of the STS operation at open-pit mines is formulated, derived and analyzed. We introduce the rationale and general principles for the functional criterion formation, its general form, as well as variations for various STS structures: a mixed truck fleet and a homogeneous shovel fleet, a mixed shove! fleet and a homogeneous truck fleet, mixed truck and shovel fleets. The possibility of assessing the quality of the STS operation is of great importance for identifying the main directions for improving their operational performance and operating quality, optimizing the main performance indicators by the qualify criterion, and. as a result, for possible saving of material and technical resources for open-pit mining. Improvement of the quality of the STS operation also allows increasing the mining safety and decreasing the atmosphere pollution - by means of possible reducing of the number of the operating trucks.

A complete graphical criterion for the adjustment formula in mediation analysis.

Science.gov (United States)

Shpitser, Ilya; VanderWeele, Tyler J

2011-03-04

Various assumptions have been used in the literature to identify natural direct and indirect effects in mediation analysis. These effects are of interest because they allow for effect decomposition of a total effect into a direct and indirect effect even in the presence of interactions or non-linear models. In this paper, we consider the relation and interpretation of various identification assumptions in terms of causal diagrams interpreted as a set of non-parametric structural equations. We show that for such causal diagrams, two sets of assumptions for identification that have been described in the literature are in fact equivalent in the sense that if either set of assumptions holds for all models inducing a particular causal diagram, then the other set of assumptions will also hold for all models inducing that diagram. We moreover build on prior work concerning a complete graphical identification criterion for covariate adjustment for total effects to provide a complete graphical criterion for using covariate adjustment to identify natural direct and indirect effects. Finally, we show that this criterion is equivalent to the two sets of independence assumptions used previously for mediation analysis.

Rupture prediction for induction bends under opening mode bending with emphasis on strain localization

International Nuclear Information System (INIS)

Mitsuya, Masaki; Sakanoue, Takashi

2015-01-01

This study focuses on the opening mode of induction bends; this mode represents the deformation outside a bend. Bending experiments on induction bends are shown and the manner of failure of these bends was investigated. Ruptures occur at the intrados of the bends, which undergo tensile stress, and accompany the local reduction of wall thickness, i.e., necking that indicates strain localization. By implementing finite element analysis (FEA), it was shown that the rupture is dominated not by the fracture criterion of material but by the initiation of strain localization that is a deformation characteristic of the material. These ruptures are due to the rapid increase of local strain after the initiation of strain localization and suddenly reach the fracture criterion. For the evaluation of the deformability of the bends, a method based on FEA that can predict the displacement at the rupture is proposed. We show that the yield surface shape and the true stress–strain relationship after uniform elongation have to be defined on the basis of the actual properties of the bend material. The von Mises yield criterion, which is commonly used in cases of elastic–plastic FEA, could not predict the rupture and overestimated the deformability. In contrast, a yield surface obtained by performing tensile tests on a biaxial specimen could predict the rupture. The prediction of the rupture was accomplished by an inverse calibration method that determined the true stress-strain relationship after uniform elongation. As an alternative to the inverse calibration, a simple extrapolation method of the true stress-strain relationship after uniform elongation which can predict the rupture is proposed. - Highlights: • A method based on FEA that can predict the displacement at the rupture is proposed. • The yield surface shape and the true stress–strain have to be defined precisely. • The von Mises yield criterion overestimated the deformability. • The ruptures are due to the

The New DSM-5 Impairment Criterion: A Challenge to Early Autism Spectrum Disorder Diagnosis?

Science.gov (United States)

Zander, Eric; Bölte, Sven

2015-01-01

The possible effect of the DSM-5 impairment criterion on diagnosing autism spectrum disorder (ASD) in young children was examined in 127 children aged 20-47 months with a DSM-IV-TR clinical consensus diagnosis of ASD. The composite score of the Vineland Adaptive Behavior Scales (VABS) served as a proxy for the DSM-5 impairment criterion. When…

Work Engagement in Serbia: Psychometric Properties of the Serbian Version of the Utrecht Work Engagement Scale (UWES

Directory of Open Access Journals (Sweden)

Ivana B. Petrović

2017-10-01

Full Text Available Work engagement is defined as a positive, affective-motivational state of work-related well-being characterized by vigor, dedication and absorption. The Utrecht Work Engagement Scale (UWES is the most frequently used measure of work engagement. The aim of this study was to analyze the psychometric properties of the Serbian versions of the UWES-17 and UWES-9. The sample consisted of 860 employees from a number of organizations and jobs across Serbia. Based on the UWES-17 findings, the data confirm both the three-factor and one-factor solutions by giving a slight advantage to the three-factor solution. As for the UWES-9, based on the PCFA and CFA, the one-factor solution was obtained as the preferred one. Taking into account the UWES-9 reliability and correlation patterns of its subscales with other well-being variables, both one- and three-factor solutions of the UWES-9 are suggested for future research. Serbian versions of both the UWES-17 and UWES-9 have satisfactory psychometric properties with high reliability, factorial structure in line with the theoretical model, and good predictive validity. The study contributes to enhanced understanding of work engagement by offering an insight from the Serbian cultural and economic context, significantly different from the UWES originating setting. There is still a need for exploring how employees from Serbia conceptualize work engagement, as well as for further, more stringent investigating of the cultural invariance of the UWES factorial structure.

Work Engagement in Serbia: Psychometric Properties of the Serbian Version of the Utrecht Work Engagement Scale (UWES).

Science.gov (United States)

Petrović, Ivana B; Vukelić, Milica; Čizmić, Svetlana

2017-01-01

Work engagement is defined as a positive, affective-motivational state of work-related well-being characterized by vigor, dedication and absorption. The Utrecht Work Engagement Scale (UWES) is the most frequently used measure of work engagement. The aim of this study was to analyze the psychometric properties of the Serbian versions of the UWES-17 and UWES-9. The sample consisted of 860 employees from a number of organizations and jobs across Serbia. Based on the UWES-17 findings, the data confirm both the three-factor and one-factor solutions by giving a slight advantage to the three-factor solution. As for the UWES-9, based on the PCFA and CFA, the one-factor solution was obtained as the preferred one. Taking into account the UWES-9 reliability and correlation patterns of its subscales with other well-being variables, both one- and three-factor solutions of the UWES-9 are suggested for future research. Serbian versions of both the UWES-17 and UWES-9 have satisfactory psychometric properties with high reliability, factorial structure in line with the theoretical model, and good predictive validity. The study contributes to enhanced understanding of work engagement by offering an insight from the Serbian cultural and economic context, significantly different from the UWES originating setting. There is still a need for exploring how employees from Serbia conceptualize work engagement, as well as for further, more stringent investigating of the cultural invariance of the UWES factorial structure.

Local Thermodynamic Equilibrium in Laser-Induced Breakdown Spectroscopy: Beyond the McWhirter criterion

International Nuclear Information System (INIS)

Cristoforetti, G.; De Giacomo, A.; Dell'Aglio, M.; Legnaioli, S.; Tognoni, E.; Palleschi, V.; Omenetto, N.

2010-01-01

In the Laser-Induced Breakdown Spectroscopy (LIBS) technique, the existence of Local Thermodynamic Equilibrium (LTE) is the essential requisite for meaningful application of theoretical Boltzmann-Maxwell and Saha-Eggert expressions that relate fundamental plasma parameters and concentration of analyte species. The most popular criterion reported in the literature dealing with plasma diagnostics, and usually invoked as a proof of the existence of LTE in the plasma, is the McWhirter criterion [R.W.P. McWhirter, in: Eds. R.H. Huddlestone, S.L. Leonard, Plasma Diagnostic Techniques, Academic Press, New York, 1965, pp. 201-264]. However, as pointed out in several papers, this criterion is known to be a necessary but not a sufficient condition to insure LTE. The considerations reported here are meant to briefly review the theoretical analysis underlying the concept of thermodynamic equilibrium and the derivation of the McWhirter criterion, and to critically discuss its application to a transient and non-homogeneous plasma, like that created by a laser pulse on solid targets. Specific examples are given of theoretical expressions involving relaxation times and diffusion coefficients, as well as a discussion of different experimental approaches involving space and time-resolved measurements that could be used to complement a positive result of the calculation of the minimum electron number density required for LTE using the McWhirter formula. It is argued that these approaches will allow a more complete assessment of the existence of LTE and therefore permit a better quantitative result. It is suggested that the mere use of the McWhirter criterion to assess the existence of LTE in laser-induced plasmas should be discontinued.

High school dropouts: interactions between social context, self-perceptions, school engagement, and student dropout.

Science.gov (United States)

Fall, Anna-Mária; Roberts, Greg

2012-08-01

Research suggests that contextual, self-system, and school engagement variables influence dropping out from school. However, it is not clear how different types of contextual and self-system variables interact to affect students' engagement or contribute to decisions to dropout from high school. The self-system model of motivational development represents a promising theory for understanding this complex phenomenon. The self-system model acknowledges the interactive and iterative roles of social context, self-perceptions, school engagement, and academic achievement as antecedents to the decision to dropout of school. We analyzed data from the Education Longitudinal Study of 2002-2004 in the context of the self-system model, finding that perception of social context (teacher support and parent support) predicts students' self-perceptions (perception of control and identification with school), which in turn predict students' academic and behavioral engagement, and academic achievement. Further, students' academic and behavioral engagement and achievement in 10th grade were associated with decreased likelihood of dropping out of school in 12th grade. Published by Elsevier Ltd.

High school dropouts: Interactions between social context, self-perceptions, school engagement, and student dropout☆

Science.gov (United States)

Fall, Anna-Mária; Roberts, Greg

2012-01-01

Research suggests that contextual, self-system, and school engagement variables influence dropping out from school. However, it is not clear how different types of contextual and self-system variables interact to affect students’ engagement or contribute to decisions to dropout from high school. The self-system model of motivational development represents a promising theory for understanding this complex phenomenon. The self-system model acknowledges the interactive and iterative roles of social context, self-perceptions, school engagement, and academic achievement as antecedents to the decision to dropout of school. We analyzed data from the Education Longitudinal Study of 2002–2004 in the context of the self-system model, finding that perception of social context (teacher support and parent support) predicts students’ self-perceptions (perception of control and identification with school), which in turn predict students’ academic and behavioral engagement, and academic achievement. Further, students’ academic and behavioral engagement and achievement in 10th grade were associated with decreased likelihood of dropping out of school in 12th grade. PMID:22153483

Multidimensional adaptive testing with a minimum error-variance criterion

NARCIS (Netherlands)

van der Linden, Willem J.

1997-01-01

The case of adaptive testing under a multidimensional logistic response model is addressed. An adaptive algorithm is proposed that minimizes the (asymptotic) variance of the maximum-likelihood (ML) estimator of a linear combination of abilities of interest. The item selection criterion is a simple

A Criterion-Referenced Approach to Student Ratings of Instruction

Science.gov (United States)

Meyer, J. Patrick; Doromal, Justin B.; Wei, Xiaoxin; Zhu, Shi

2017-01-01

We developed a criterion-referenced student rating of instruction (SRI) to facilitate formative assessment of teaching. It involves four dimensions of teaching quality that are grounded in current instructional design principles: Organization and structure, Assessment and feedback, Personal interactions, and Academic rigor. Using item response…

Is a Transdisciplinary Theory of Engagement in Organized Settings Possible? A Concept Analysis of the Literature on Employee Engagement, Consumer Engagement and Patient Engagement.

Science.gov (United States)

Graffigna, Guendalina

2017-01-01

Organizations are experiencing increased competition, disruptive innovation, and continuous changes in their social and economic context. Furthermore, the decrease of resources (economic and human) in such a demanding context make it imperative for organizations to find new models and strategies to make their service delivery more sustainable at the economic, environmental and psychological levels. In such a complex scenario the concept of engagement of the individuals involved in organized settings (either as service providers or as final receivers) is a promising lever for innovation. However, despite the number of studies on the matter, the debate on engagement is still very fragmented because the corpus of literature addressing the different areas of engagement is divided and diverse in its nature. In this paper, we discuss the results of a conceptual analysis of the literature conducted in order to investigate overlapping features and areas of divergence among three different areas of investigation and application of the engagement phenomenon in organized settings: the domains of employee engagement, consumer engagement, and patient engagement. These are deliberately selected as prototypical of the phenomenon of engagement along the "inside/outside" of organizational settings. The analysis consisted in a qualitative conceptual survey? Of the scholarly literature indexed with the key terms "employee engagement," "consumer engagement," and "patient engagement." We performed a key-word based survey? Of the literature in the Scopus database. A total of 163 articles were selected and analyzed. The analysis cast light on the following areas of conceptual overlap among employee, consumer and patient engagement: (1) engagement is different from empowerment and activation; (2) engagement is a multi-componential psychological experience; (3) engagement is a self-transformative experience; (4) engagement develops within a relational context; (5) engagement is a systemic

Is a Transdisciplinary Theory of Engagement in Organized Settings Possible? A Concept Analysis of the Literature on Employee Engagement, Consumer Engagement and Patient Engagement

Directory of Open Access Journals (Sweden)

Guendalina Graffigna

2017-07-01

Full Text Available Organizations are experiencing increased competition, disruptive innovation, and continuous changes in their social and economic context. Furthermore, the decrease of resources (economic and human in such a demanding context make it imperative for organizations to find new models and strategies to make their service delivery more sustainable at the economic, environmental and psychological levels. In such a complex scenario the concept of engagement of the individuals involved in organized settings (either as service providers or as final receivers is a promising lever for innovation. However, despite the number of studies on the matter, the debate on engagement is still very fragmented because the corpus of literature addressing the different areas of engagement is divided and diverse in its nature. In this paper, we discuss the results of a conceptual analysis of the literature conducted in order to investigate overlapping features and areas of divergence among three different areas of investigation and application of the engagement phenomenon in organized settings: the domains of employee engagement, consumer engagement, and patient engagement. These are deliberately selected as prototypical of the phenomenon of engagement along the “inside/outside” of organizational settings. The analysis consisted in a qualitative conceptual survey? Of the scholarly literature indexed with the key terms “employee engagement,” “consumer engagement,” and “patient engagement.” We performed a key-word based survey? Of the literature in the Scopus database. A total of 163 articles were selected and analyzed. The analysis cast light on the following areas of conceptual overlap among employee, consumer and patient engagement: (1 engagement is different from empowerment and activation; (2 engagement is a multi-componential psychological experience; (3 engagement is a self-transformative experience; (4 engagement develops within a relational context

Bayesian Information Criterion as an Alternative way of Statistical Inference

Directory of Open Access Journals (Sweden)

Nadejda Yu. Gubanova

2012-05-01

Full Text Available The article treats Bayesian information criterion as an alternative to traditional methods of statistical inference, based on NHST. The comparison of ANOVA and BIC results for psychological experiment is discussed.

Strengthening stakeholder-engaged research and research on stakeholder engagement.

Science.gov (United States)

Ray, Kristin N; Miller, Elizabeth

2017-06-01

Stakeholder engagement is an emerging field with little evidence to inform best practices. Guidelines are needed to improve the quality of research on stakeholder engagement through more intentional planning, evaluation and reporting. We developed a preliminary framework for planning, evaluating and reporting stakeholder engagement, informed by published conceptual models and recommendations and then refined through our own stakeholder engagement experience. Our proposed exploratory framework highlights contexts and processes to be addressed in planning stakeholder engagement, and potential immediate, intermediate and long-term outcomes that warrant evaluation. We use this framework to illustrate both the minimum information needed for reporting stakeholder-engaged research and the comprehensive detail needed for reporting research on stakeholder engagement.

An Elementary Proof of a Criterion for Linear Disjointness

Science.gov (United States)

Dobbs, David E.

2013-01-01

An elementary proof using matrix theory is given for the following criterion: if "F"/"K" and "L"/"K" are field extensions, with "F" and "L" both contained in a common extension field, then "F" and "L" are linearly disjoint over "K" if (and only if) some…

Workplace Bullying and Work Engagement: A Self-Determination Model.

Science.gov (United States)

Goodboy, Alan K; Martin, Matthew M; Bolkan, San

2017-06-01

This study modeled motivational mechanisms that explain the negative effects of workplace bullying on work engagement. Guided by self-determination theory, workplace bullying was predicted to decrease worker engagement indirectly, due to the denial of employees' basic psychological needs and their intrinsic motivation to work. From a sample of 243 full-time employees, serial multiple mediation models revealed that the indirect relationships between workplace bullying and work engagement (i.e., vigor, dedication, absorption) were serially mediated by basic psychological needs and intrinsic motivation to work. In support of self-determination theory, this study revealed that workplace bullying indirectly disengages employees from their work by denying them of their autonomy and relatedness needs and thwarting their motivation to perform work in a fulfilling way.

Suitability of the Yield Criterion in Numerical Simulation of Stretch Bending of Aluminum Extrusions

International Nuclear Information System (INIS)

Li, X.Q.; Zhou, X.B.; Wu, X.D.; Gao, H.Z.

2005-01-01

Stretch bending is commonly used to shape thin-walled extrusions in aerospace and automotive industries. The extrusions are pre-stretched and bent over rigid curved dies. Effective application of this process demands sufficient knowledge of how different parameters influence the final shape of the product. Numerical simulation is an effective approach to investigate these issues presently. However, the validity of simulation result depends strongly on a precise description of the mechanical behavior of the material. Due to crystallographic texture caused by the extrusion process, aluminium extrusions exhibit significant plastic anisotropy which need be described by advanced constitutive model. In this work stretch bending of aluminum extrusions is simulated by using different anisotropic criteria (Hill quadratic, Barlat three-parameter). The influence of two yield criteria on predicting maximum die force immediately before unloading, permanent sagging and vertical springback displacement in the middle section of extrusion are compared. Maximum die force and springback calculated by two yield criteria are found to be almost same. Permanent sagging is obviously underestimated by two yield criteria, however, prediction by Barlat three-parameter is closer to experiment than one of Hill quadratic yield criterion

Sexual Harassment, Self Esteem and Academic Engagement as ...

African Journals Online (AJOL)

The purpose of the present study was to investigate the extent to which sexual harassment, self-esteem, and academic engagement predict academic success of female secondary school students in Gondar city. Correlational design was employed to answer the research questions raised. Respondents were 366 female ...

Prediction of crank torque and pedal angle profiles during pedaling movements by biomechanical optimization

DEFF Research Database (Denmark)

Farahani, Saeed Davoudabadi; Bertucci, William; Andersen, Michael Skipper

2015-01-01

This paper introduces the inverse-inverse dynamics method for prediction of human movement and applies it to prediction of cycling motions. Inverse-inverse dynamics optimizes a performance criterion by variation of a parameterized movement. First, a musculoskeletal model of cycling is built in th...

Multimodel Predictive System for Carbon Dioxide Solubility in Saline Formation Waters

Energy Technology Data Exchange (ETDEWEB)

Wang, Zan; Small, Mitchell J; Karamalidis, Athanasios K

2013-02-05

The prediction of carbon dioxide solubility in brine at conditions relevant to carbon sequestration (i.e., high temperature, pressure, and salt concentration (T-P-X)) is crucial when this technology is applied. Eleven mathematical models for predicting CO{sub 2} solubility in brine are compared and considered for inclusion in a multimodel predictive system. Model goodness of fit is evaluated over the temperature range 304–433 K, pressure range 74–500 bar, and salt concentration range 0–7 m (NaCl equivalent), using 173 published CO{sub 2} solubility measurements, particularly selected for those conditions. The performance of each model is assessed using various statistical methods, including the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC). Different models emerge as best fits for different subranges of the input conditions. A classification tree is generated using machine learning methods to predict the best-performing model under different T-P-X subranges, allowing development of a multimodel predictive system (MMoPS) that selects and applies the model expected to yield the most accurate CO{sub 2} solubility prediction. Statistical analysis of the MMoPS predictions, including a stratified 5-fold cross validation, shows that MMoPS outperforms each individual model and increases the overall accuracy of CO{sub 2} solubility prediction across the range of T-P-X conditions likely to be encountered in carbon sequestration applications.

The academic rewards of socially-oriented happiness: Interdependent happiness promotes academic engagement.

Science.gov (United States)

Datu, Jesus Alfonso D; King, Ronnel B; Valdez, Jana Patricia M

2017-04-01

Interdependent happiness has been found to be positively associated with optimal psychological outcomes in collectivist cultures. However, the association between interdependent happiness and key academic outcomes has remained unexplored. The current study examined the association of interdependent happiness with key academic outcomes such as autonomous motivation, engagement, and achievement using both cross-sectional (Study 1) and longitudinal (Study 2) approaches. Study 1 revealed that interdependent happiness positively predicted academic engagement (partly) via autonomous motivation. Study 2 showed that prior interdependent happiness positively predicted subsequent academic engagement even after controlling for autoregressor effects. In addition, reciprocal associations among the key variables were found. Taken together, results of the two studies suggest that interdependent happiness plays an adaptive role in the academic context especially in a collectivist cultural setting. Theoretical and practical implications are discussed. Copyright © 2016 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

AUTOMATIC RECOGNITION OF FALLS IN GAIT-SLIP: A HARNESS LOAD CELL BASED CRITERION

OpenAIRE

Yang, Feng; Pai, Yi-Chung

2011-01-01

Over-head-harness systems, equipped with load cell sensors, are essential to the participants’ safety and to the outcome assessment in perturbation training. The purpose of this study was to first develop an automatic outcome recognition criterion among young adults for gait-slip training and then verify such criterion among older adults. Each of 39 young and 71 older subjects, all protected by safety harness, experienced 8 unannounced, repeated slips, while walking on a 7-m walkway. Each tri...

A new repair criterion for steam generator tubes with axial cracks based on probabilistic integrity assessment

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyun-Su; Oh, Chang-Kyun [KEPCO Engineering and Construction Company, Inc., 269, Hyeoksin-ro, Gimcheon, Gyeongsangbuk-do 39660 (Korea, Republic of); Chang, Yoon-Suk, E-mail: yschang@khu.ac.kr [Department of Nuclear Engineering, College of Engineering, Kyung Hee University, 1732 Deokyoungdaero, Giheung, Yongin, Gyeonggi 446-701 (Korea, Republic of)

2017-03-15

Highlights: • Probabilistic assessment was performed for axially cracked steam generator tubes. • The threshold crack sizes were determined based on burst pressures of the tubes. • A new repair criterion was suggested as a function of operation time. - Abstract: Steam generator is one of the major components in a nuclear power plant, and it consists of thousands of thin-walled tubes. The operating record of the steam generators has indicated that a number of axial cracks due to stress corrosion have been frequently detected in the tubes. Since the tubes are closely related to the safety and also the efficiency of a nuclear power plant, an establishment of the appropriate repair criterion for the defected tubes and its applications are necessary. The objective of this paper is to develop an accurate repair criterion for the tubes with axial cracks. To do this, a thorough review is performed on the key parameters affecting the tube integrity, and then the probabilistic integrity assessment is carried out by considering the various uncertainties. In addition, the sizes of critical crack are determined by comparing the burst pressure of the cracked tube with the required performance criterion. Based on this result, the new repair criterion for the axially cracked tubes is defined from the reasonably conservative value such that the required performance criterion in terms of the burst pressure is able to be met during the next operating period.

Harnessing Youth and Young Adult Culture: Improving the Reach and Engagement of the truth® Campaign.

Science.gov (United States)

Hair, Elizabeth; Pitzer, Lindsay; Bennett, Morgane; Halenar, Michael; Rath, Jessica; Cantrell, Jennifer; Dorrler, Nicole; Asche, Eric; Vallone, Donna

2017-07-01

The national youth and young adult tobacco prevention mass media campaign, truth®, relaunched in 2014 with the goal of creating "the generation that ends smoking." The objective of this study was to assess whether the strategy of airing truth ads during popular, culturally relevant televised events was associated with higher ad and brand awareness and increases in social media engagement. Awareness of six truth advertisements that aired during popular television events and self-reported social media engagement were assessed via cross-sectional online surveys of youth and young adults aged 15-21 years. Social engagement was also measured using separate Twitter and YouTube metrics. Logistic regression models predicted self-reported social engagement and any ad awareness, and a negative binomial regression predicted the total social media engagement across digital platforms. The study found that viewing a popular televised event was associated with higher odds of ad awareness and social engagement. The results also indicate that levels of social media engagement for an event period are greater than for a nonevent period. The findings demonstrate that premiering advertisements during a popular, culturally relevant televised event is associated with higher awareness of truth ads and increased social engagement related to the campaign, controlling for variables that might also influence the response to campaign messages.

Ductile Crack Initiation Criterion with Mismatched Weld Joints Under Dynamic Loading Conditions.

Science.gov (United States)

An, Gyubaek; Jeong, Se-Min; Park, Jeongung

2018-03-01

Brittle failure of high toughness steel structures tends to occur after ductile crack initiation/propagation. Damages to steel structures were reported in the Hanshin Great Earthquake. Several brittle failures were observed in beam-to-column connection zones with geometrical discontinuity. It is widely known that triaxial stresses accelerate the ductile fracture of steels. The study examined the effects of geometrical heterogeneity and strength mismatches (both of which elevate plastic constraints due to heterogeneous plastic straining) and loading rate on critical conditions initiating ductile fracture. This involved applying the two-parameter criterion (involving equivalent plastic strain and stress triaxiality) to estimate ductile cracking for strength mismatched specimens under static and dynamic tensile loading conditions. Ductile crack initiation testing was conducted under static and dynamic loading conditions using circumferentially notched specimens (Charpy type) with/without strength mismatches. The results indicated that the condition for ductile crack initiation using the two parameter criterion was a transferable criterion to evaluate ductile crack initiation independent of the existence of strength mismatches and loading rates.

Criterion III: Maintenance of rangeland productive capacity [Chapter 4

Science.gov (United States)

G. R. Evans; R. A. Washmgton-Allen; R. D. Child; J. E. Mitchell; B. R. Bobowskl; R. V. Loper; B. H. Allen-Diaz; D. W. Thompson; G. R. Welling; T. B. Reuwsaat

2010-01-01

Maintenance of rangeland productive capacity is one of five criteria established by the Sustainable Rangelands Roundtable (SRR) to monitor and assess rangeland sustainable management. Within this criterion, six indicators were developed through the Delphi Process and the expert opinions of academicians, rangeland scientists, rangeland management agency personnel, non-...

Role stress and work engagement as antecedents of job satisfaction in Spanish workers

Directory of Open Access Journals (Sweden)

Alejandro Orgambídez-Ramos

2014-01-01

Full Text Available Purpose: According to the Job Demands-Resources (JDR model, engagement and job satisfaction may be produce by two types of working conditions: job demands (i.e. role stress and job resources (i.e. self-efficacy. This study examines the role of role stress and work engagement as antecedents of job satisfaction in a sample of Spanish workers. Design/methodology/approach: This study comprised a sample of 435 Spanish workers. A cross sectional study was used to examine the relationship between role stress, work engagement and job satisfaction. Data were gathered based on personal administered questionnaires. Findings and Originality/value: Hierarchical multiple regression models have revealed that job satisfaction was significantly predicted by role stress and work engagement. Results support JDR model by showing that positive outcomes, such as job satisfaction can be predicted by motivational process and job demands. Research limitations/implications: The cross-sectional design cannot evidence of causal relationships. This study relies on self-reports, which might increase the risk of common method variance. Practical implications: On a practical level, the JDR model provides a framework for understanding motivating workplaces and engaged and satisfied employees. Originality/value: The JDR model could be useful in designing strategies for which engaged employees may be advantageous to improving the quality of services, while at the same time increasing employees’ job satisfaction and well-being.

A comparative calculation of the wind turbines capacities on the basis of the L-{sigma} criterion

Energy Technology Data Exchange (ETDEWEB)

Menet, Jean-Luc; Valdes, Laurent-Charles; Menart, Bruno [Universite de Valenciennes et du Hainaut-Cambresis, Groupe de Recherche Energies et Environnement, Valenciennes, 59 (France)

2001-04-01

Usually, wind sites are equipped with fast-running Horizontal Axis Wind Turbines of the airscrew type, which has a high efficiency. In this article, the argument is put forward that the choice of a wind turbine must not be based only on high efficiency. We propose a comparative criterion adapted to the comparison of a horizontal axis wind turbine with a vertical axis wind turbine: the L-{sigma} criterion. This criterion consists in comparing wind turbines which intercept the same front width of wind, by allocating them a same reference value of the maximal mechanical stress on the blades or the paddles. On the basis of this criterion, a quantitative comparison points to a clear advantage of the Savonius rotors, because of their lower angular velocity, and provides some elements for the improvement of their rotor. (Author)

Early Childhood Risk Factors for Mealtime TV Exposure and Engagement in Low-Income Families.

Science.gov (United States)

Domoff, Sarah E; Lumeng, Julie C; Kaciroti, Niko; Miller, Alison L

To identify whether child and mother characteristics in early childhood predict TV exposure and engagement during mealtime in middle childhood. A total of 220 low-income mother-child dyads participated. Children were 4.26 years old (SD = 0.51) at baseline and 5.94 years (SD = 0.68) at 2-year follow-up. Mothers completed baseline measures of child negative emotionality and parenting practices. Family mealtimes were video recorded and coded for background TV exposure and child TV engagement. Multinomial logistic regression tested whether child emotionality and parenting practices during early childhood predicted risk of child TV exposure or engagement during mealtime, relative to no TV use, 2 years later. Children with greater negative emotionality in early childhood were more likely to engage with TV during mealtime than to have no TV. Similarly, early parenting disciplinary practices characterized by over-reactivity and laxness increased the risk for child TV engagement versus no TV during mealtime approximately 2 years later. We identified 2 factors that associated with an increased risk for TV viewing during meals. Helping parents manage child negative emotionality using positive parenting strategies might reduce later child TV engagement and improve the quality of family mealtimes. Copyright © 2016 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Criterion validity and reliability of a smartphone delivered sub-maximal fitness test for people with type 2 diabetes

DEFF Research Database (Denmark)

Brinklov, Cecilie Fau; Thorsen, Ida Kær; Karstoft, Kristian

2016-01-01

Background: Prevention of multi-morbidities following non-communicable diseases requires a systematic registration of adverse modifiable risk factors, including low physical fitness. The aim of the study was to establish criterion validity and reliability of a smartphone app (InterWalk) delivered....... The algorithm was validated using leave-one-out cross validation. Test-retest reliability was tested in a subset of participants (N = 10). Results: The overall VO2peak prediction of the algorithm (R2) was 0.60 and 0.45 when the smartphone was placed in the pockets of the pants and jacket, respectively (p ... calorimetry and the acceleration (vector magnitude) from the smartphone was obtained. The vector magnitude was used to predict VO2peak along with the co-variates weight, height and sex. The validity of the algorithm was tested when the smartphone was placed in the right pocket of the pants or jacket...

The college journey and academic engagement: how metaphor use enhances identity-based motivation.

Science.gov (United States)

Landau, Mark J; Oyserman, Daphna; Keefer, Lucas A; Smith, George C

2014-05-01

People commonly talk about goals metaphorically as destinations on physical paths extending into the future or as contained in future periods. Does metaphor use have consequences for people's motivation to engage in goal-directed action? Three experiments examine the effect of metaphor use on students' engagement with their academic possible identity: their image of themselves as academically successful graduates. Students primed to frame their academic possible identity using the goal-as-journey metaphor reported stronger academic intention, and displayed increased effort on academic tasks, compared to students primed with a nonacademic possible identity, a different metaphoric framing (goal-as-contained-entity), and past academic achievements (Studies 1-2). This motivating effect persisted up to a week later as reflected in final exam performance (Study 3). Four experiments examine the cognitive processes underlying this effect. Conceptual metaphor theory posits that an accessible metaphor transfers knowledge between dissimilar concepts. As predicted in this paradigm, a journey-metaphoric framing of a possible academic identity transferred confidence in the procedure, or action sequence, required to attain that possible identity, which in turn led participants to perceive that possible identity as more connected to their current identity (Study 4). Drawing on identity-based motivation theory, we hypothesized that strengthened current/possible identity connection would mediate the journey framing's motivating effect. This mediational process predicted students' academic engagement (Study 5) and an online sample's engagement with possible identities in other domains (Study 6). Also as predicted, journey framing increased academic engagement particularly among students reporting a weak connection to their academic possible identity (Study 7).

Positive engagement and job resources in dental practice.

Science.gov (United States)

Gorter, Ronald C; Te Brake, Hans J H M; Hoogstraten, Johan; Eijkman, Michiel A J

2008-02-01

The aim of this study is to determine the level of engagement among dentists, and subsequently, to investigate which dental job resources are positively correlated with engagement. By stratifying on gender, age, and region, a representative sample of 848 general dental practitioners was drawn at random, plus an extra group of 95 female dentists for gender comparison purposes. Engagement was assessed using the Utrecht Work Engagement Scale (UWES), consisting of three subscales: Vigor, Dedication; and Absorption. Job resources were measured using the Dentists' Experienced Job Resources Scale (DEJRS). Six hundred and thirty two dentists (67%) responded, 76% male and 25% female. Mean age: 44.6 years (SD = 9.0). Engagement: Dedication and Absorption mean scores were higher among dentists when compared with manual norm scores, based upon a variety of professions, whereas Vigor mean scores were comparable to manual norm scores. Job resources:'Immediate results / Aesthetics' and '(Long term) Patient results' showed highest mean scores among all dentists. Gender differences were found on '(Long term) Patient results' and 'Patient care'. Engagement and job resources: All DEJRS subscales and the full scale showed statistically significant positive correlations (pmcc) with the UWES subscales. Dentists showed relatively high mean scores on an engagement measure when compared with manual norm scores. No gender differences in mean scores were found. Job resources most valued were 'Immediate results / Aesthetics'. The job resources, 'Idealism/Pride' and 'Patient care', showed most predictive value with regard to engagement among dentists. In order to prevent burnout, it is recommended to raise dentists' awareness of the importance to create sufficient time and space for stimulating aspects in their work.

Predicting FLDs Using a Multiscale Modeling Scheme

Science.gov (United States)

Wu, Z.; Loy, C.; Wang, E.; Hegadekatte, V.

2017-09-01

The measurement of a single forming limit diagram (FLD) requires significant resources and is time consuming. We have developed a multiscale modeling scheme to predict FLDs using a combination of limited laboratory testing, crystal plasticity (VPSC) modeling, and dual sequential-stage finite element (ABAQUS/Explicit) modeling with the Marciniak-Kuczynski (M-K) criterion to determine the limit strain. We have established a means to work around existing limitations in ABAQUS/Explicit by using an anisotropic yield locus (e.g., BBC2008) in combination with the M-K criterion. We further apply a VPSC model to reduce the number of laboratory tests required to characterize the anisotropic yield locus. In the present work, we show that the predicted FLD is in excellent agreement with the measured FLD for AA5182 in the O temper. Instead of 13 different tests as for a traditional FLD determination within Novelis, our technique uses just four measurements: tensile properties in three orientations; plane strain tension; biaxial bulge; and the sheet crystallographic texture. The turnaround time is consequently far less than for the traditional laboratory measurement of the FLD.

Stability Criterion for a Finned Spinning Projectile

OpenAIRE

S. D. Naik

2000-01-01

The state-of-the-art in gun projectile technology has been used for the aerodynamic stabilisation.This approach is acceptable for guided and controlled rockets but the free-flight rockets suffer fromunacceptable dispersion. Sabot projectiles with both spin and fms developed during the last decadeneed careful analysis. In this study, the second method of Liapunov has been used to develop stability criterion for a projectile to be designed with small fins and is made to spin in the flight. This...

The Goiania accident: release from hospital criterion

International Nuclear Information System (INIS)

Falcao, R.C.; Hunt, J.

1990-01-01

On the thirteenth of September 1987, a 1357 Ci Cesium source was removed from the 'Instituto de Radiologia de Goiania' - probably two or three days later the source was opened, causing the internal and external contamination of 247 people, and part of the city of Goiania. This paper describes the release from hospital criterion of the contaminated patients, based on radiation protection principles which were developed for this case. The estimate of the biological half-life for cesium is also described. (author) [pt

Signal Detection with Criterion Noise: Applications to Recognition Memory

Science.gov (United States)

Benjamin, Aaron S.; Diaz, Michael; Wee, Serena

2009-01-01

A tacit but fundamental assumption of the theory of signal detection is that criterion placement is a noise-free process. This article challenges that assumption on theoretical and empirical grounds and presents the noisy decision theory of signal detection (ND-TSD). Generalized equations for the isosensitivity function and for measures of…

Valence electron structure of cast iron and graphltization behaviour criterion of elements

Institute of Scientific and Technical Information of China (English)

刘志林; 李志林; 孙振国; 杨晓平; 陈敏

1995-01-01

The valence electron structure of common alloy elements in phases of cast iron is calculated- The relationship between the electron structure of alloy elements and equilibrium, non-equilibrium solidification and graphitization is revealed by defining the bond energy of the strongest bond in a phase as structure formation factor S. A criterion of graphitization behaviour of elements is advanced with the critical value of the structure formation factor of graphite and the n of the strongest covalent bond in cementite. It is found that this theory conforms to practice very well when the criterion is applied to the common alloy elements.

Definition of the generalized criterion of estimation of ecological purity of textile products

International Nuclear Information System (INIS)

Gintibidze, N.; Valishvili, T.

2009-01-01

One of actual problems is the estimation of hygienic and ecological properties of fabrics on the basis of the data on the properties of initial fiber. In the present article, the definition of generalized criterion of the estimation of ecological purity of textile products is discussed. The estimation is based on the International Standard EKO-TEX-100, regulating the contents of inorganic and organic compounds in textile production. The determination of all listed substances is made according to appropriate techniques for each parameter. The quantity of substances is determined and compared with norms. The judgement about ecological purity is made by separate parameters. There is no uniform parameter which could estimate the degree of ecological purity of textile products. For calculating the generalized criterion of estimation of ecological purity of textile products, it is offered to estimate each criterion by the points corresponding to each factor. The textile product is recognized as ecologically pure (environment friendly) if the total estimate is more than 1. (author)

Estimating Model Prediction Error: Should You Treat Predictions as Fixed or Random?

Science.gov (United States)

Wallach, Daniel; Thorburn, Peter; Asseng, Senthold; Challinor, Andrew J.; Ewert, Frank; Jones, James W.; Rotter, Reimund; Ruane, Alexander

2016-01-01

Crop models are important tools for impact assessment of climate change, as well as for exploring management options under current climate. It is essential to evaluate the uncertainty associated with predictions of these models. We compare two criteria of prediction error; MSEP fixed, which evaluates mean squared error of prediction for a model with fixed structure, parameters and inputs, and MSEP uncertain( X), which evaluates mean squared error averaged over the distributions of model structure, inputs and parameters. Comparison of model outputs with data can be used to estimate the former. The latter has a squared bias term, which can be estimated using hindcasts, and a model variance term, which can be estimated from a simulation experiment. The separate contributions to MSEP uncertain (X) can be estimated using a random effects ANOVA. It is argued that MSEP uncertain (X) is the more informative uncertainty criterion, because it is specific to each prediction situation.

A graphical criterion for working fluid selection and thermodynamic system comparison in waste heat recovery

International Nuclear Information System (INIS)

Xi, Huan; Li, Ming-Jia; He, Ya-Ling; Tao, Wen-Quan

2015-01-01

In the present study, we proposed a graphical criterion called CE diagram by achieving the Pareto optimal solutions of the annual cash flow and exergy efficiency. This new graphical criterion enables both working fluid selection and thermodynamic system comparison for waste heat recovery. It's better than the existing criterion based on single objective optimization because it is graphical and intuitionistic in the form of diagram. The features of CE diagram were illustrated by studying 5 examples with different heat-source temperatures (ranging between 100 °C to 260 °C), 26 chlorine-free working fluids and two typical ORC systems including basic organic Rankine cycle(BORC) and recuperative organic Rankine cycle (RORC). It is found that the proposed graphical criterion is feasible and can be applied to any closed loop waste heat recovery thermodynamic systems and working fluids. - Highlights: • A graphical method for ORC system comparison/working fluid selection was proposed. • Multi-objectives genetic algorithm (MOGA) was applied for optimizing ORC systems. • Application cases were performed to demonstrate the usage of the proposed method.

RN work engagement in generational cohorts: the view from rural US hospitals.

Science.gov (United States)

Sullivan Havens, Donna; Warshawsky, Nora E; Vasey, Joseph

2013-10-01

To describe staff nurse work engagement, identify predictors by generational cohort, present implications for nurse managers and suggest future research. A global nurse shortage looms. While an adequate supply of nurses is needed to ensure access to care, access to quality care may be enhanced by an adequate supply of highly engaged nurses-those who are dedicated, energized, and absorbed. Nurses have long reported the presence of energy depleting practice environments. Nurses practicing in professional practice environments may be more engaged. A non-experimental survey design was executed. Direct care Registered Nurses (n = 747) working in five rural acute care hospitals completed questionnaires to assess work engagement (Utrecht Work Engagement Scale-9), decisional involvement (Decisional Involvement Scale), relational coordination (Relational Coordination Survey) and the nursing practice environment (Practice Environment Scale of the Nursing Work Index). Descriptive, correlational and regression analyses examined work engagement and predictors by generational cohort. With the exception of the absorption component, no statistically significant differences in engagement emerged across generational cohorts. Predictors of engagement differed by cohort, however across all cohorts, professional nursing practice environments predicted nurse work engagement. Professional nursing practice environments are significantly associated with nurse work engagement. Enhancing nurse work engagement is a complex challenge. Generational cohorts may respond to different strategies to enhance engagement. © 2013 John Wiley & Sons Ltd.

Career Engagement: Bridging Career Counseling and Employee Engagement

Science.gov (United States)

Neault, Roberta A.; Pickerell, Deirdre A.

2011-01-01

In this article, the authors present a model of career engagement that helps bridge the gap between career counselors' focus on supporting individuals to find meaningful work and employers' desire for an engaged, productive, and committed workforce. They briefly review highlights of the employee engagement literature, introduce the Career…

Burnout, work engagement and workaholism among highly educated employees: Profiles, antecedents and outcomes

Directory of Open Access Journals (Sweden)

Hely Innanen

2014-06-01

Full Text Available The present study examined the longitudinal profiles of burnout, engagement and workaholism among highly educated employees. First, the latent profile modeling indicated two latent classes: Engaged and Exhausted-Workaholic. Second, the results revealed that employees with the Engaged profile experienced high levels of energy and dedication, whereas employees with the Exhausted-Workaholic profile experienced exhaustion, cynicism and workaholism. Social pessimism in the transition from high education to work predicted poor subjective well-being at work. Further, workaholism decreased during the career among members of the Exhausted-Workaholic profile suggesting positive direction during career. Finally, Engaged employees experienced detachment and relaxation, life satisfaction and rewards.

Comparison of ASSESS neutralization module results with actual small force engagement outcomes

International Nuclear Information System (INIS)

Gardner, B.H.; Snell, M.K.; Paulus, W.K.

1991-01-01

The ASSESS Neutralization module (Neutralization) is part of the Analytic System and Software for Evaluation of Safeguards and Security (ASSESS), a vulnerability assessment tool. Neutralization models a fire fight between security inspectors (SIs) and adversaries. This paper reports that a comparison has been made between actual outcomes of police and small military engagements and the results predicted by the Neutralization module for similar scenarios. The results of this comparison show a surprising correlation between predicted outcomes (based on numbers of combatants, weapon types, and exposures, etc.) and the actual outcomes of the engagements analyzed. The importance of this analysis is that given the defenders have intelligence on actual adversary characteristics or are protecting against a design basis threat, defense capabilities can be evaluated before an engagement. Results could then be used to develop a favorable probability of a desired outcome. For example, law enforcement agencies are frequently able to compile the number of criminals, types of weaponry, willingness to use force, etc., from analysis of crime scenes

The conservatism of the net-section stress criterion for the failure of cracked stainless steel piping

International Nuclear Information System (INIS)

Smith, E.

1991-01-01

The failure of cracked stainless steel piping can be predicted by assuming that failure conforms to a net-section stress criterion, using as input an appropriate value for the critical net-section stress together with a knowledge of the anticipated loadings. The stresses at the cracked section are usually calculated via a purely elastic analysis based on the piping being uncracked. However because the piping is built-in at its ends into a larger component, this limits the amount of elastic follow-up and, consequently, use of the net-section stress approach in this manner can lead to conservative failure predictions. This paper quantifies the extent of this conservatism, and shows that it can be quite marked. There is an additional measure of conservatism due to the fact that unstable failure need not necessarily be associated with the onset of crack extension. A key parameter with regard to both these conservatisms is L EFF , a length parameter which is a measure of the degree of elastic follow-up in the system. (author)

Cultural affordances and emotional experience: socially engaging and disengaging emotions in Japan and the United States.

Science.gov (United States)

Kitayama, Shinobu; Mesquita, Batja; Karasawa, Mayumi

2006-11-01

The authors hypothesized that whereas Japanese culture encourages socially engaging emotions (e.g., friendly feelings and guilt), North American culture fosters socially disengaging emotions (e.g., pride and anger). In two cross-cultural studies, the authors measured engaging and disengaging emotions repeatedly over different social situations and found support for this hypothesis. As predicted, Japanese showed a pervasive tendency to reportedly experience engaging emotions more strongly than they experienced disengaging emotions, but Americans showed a reversed tendency. Moreover, as also predicted, Japanese subjective well-being (i.e., the experience of general positive feelings) was more closely associated with the experience of engaging positive emotions than with that of disengaging emotions. Americans tended to show the reversed pattern. The established cultural differences in the patterns of emotion suggest the consistent and systematic cultural shaping of emotion over time.

The impact of emotional intelligence on work engagement of registered nurses: the mediating role of organisational justice.

Science.gov (United States)

Zhu, Yun; Liu, Congcong; Guo, Bingmei; Zhao, Lin; Lou, Fenglan

2015-08-01

To explore the impact of emotional intelligence and organisational justice on work engagement in Chinese nurses and to examine the mediating role of organisational justice to provide implications for promoting clinical nurses' work engagement. The importance of work engagement on nurses' well-being and quality of care has been well documented. Work engagement is significantly predicted by job resources. However, little research has concentrated simultaneously on the influence of both personal and organisational resources on nurses' work engagement. A descriptive, cross-sectional design was employed. A total of 511 nurses from four public hospitals were enrolled by multistage sampling. Data collection was undertaken using the Wong and Law Emotional Intelligence Scale, the Organizational Justice questionnaire and the Utrecht Work Engagement Scale-9. We analysed the data using structural equation modelling. Emotional intelligence and organisational justice were significant predictors and they accounted for 44% of the variance in nurses' work engagement. Bootstrap estimation confirmed an indirect effect of emotional intelligence on work engagement via organisational justice. Emotional intelligence and organisational justice positively predict work engagement and organisational justice partially mediates the relationship between emotional intelligence and work engagement. Our study supports the idea that enhancing organisational justice can increase the impact of emotional intelligence. Managers should take into account the importance of emotional intelligence and perceptions of organisational justice in human resources management and apply targeted interventions to foster work engagement. © 2015 John Wiley & Sons Ltd.

The Impact of Organizational Stress and Burnout on Client Engagement

Science.gov (United States)

Landrum, Brittany; Knight, Danica K.; Flynn, Patrick M.

2011-01-01

This paper explores the impact of organizational attributes on client engagement within substance abuse treatment. Previous research has identified organizational features, including small size, accreditation, and workplace practices that impact client engagement (Broome, Flynn, Knight, & Simpson, 2007). The current study sought to explore how aspects of the work environment impact client engagement. The sample included 89 programs located in 9 states across the U.S. Work environment measures included counselor perceptions of stress, burnout, and work satisfaction at each program, while engagement measures included client ratings of participation, counseling rapport, and treatment satisfaction. Using multiple regression, tests of moderation and mediation revealed that staff stress negatively predicted client participation in treatment. Burnout was related to stress, but was not related to participation. Two additional organizational measures – workload and influence – moderated the positive relationship between staff stress and burnout. Implications for drug treatment programs are discussed. PMID:22154029

Religious Engagement in a Risky Family Model Predicting Health in Older Black and White Seventh-day Adventists.

Science.gov (United States)

Morton, Kelly R; Lee, Jerry W; Haviland, Mark G; Fraser, Gary E

2012-11-01

In a structural equation model, associations among latent variables - Child Poverty, Risky Family exposure, Religious Engagement, Negative Social Interactions, Negative Emotionality, and Perceived Physical Health - were evaluated in 6,753 Black and White adults aged 35-106 years (M = 60.5, SD = 13.0). All participants were members of the Seventh-day Adventist church surveyed in the Biopsychosocial Religion and Health Study (BRHS). Child Poverty was positively associated with both Risky Family exposure (conflict, neglect, abuse) and Religious Engagement (intrinsic religiosity, religious coping, religiousness). Risky Family was negatively associated with Religious Engagement and positively associated with both Negative Social Interactions (intrusive, failed to help, insensitive, rejecting) and Negative Emotionality (depression, negative affect, neuroticism). Religious Engagement was negatively associated with Negative Emotionality and Negative Social Interactions at a given level of risky family. Negative Social Interactions was positively associated with Negative Emotionality, which had a direct, negative effect on Perceived Physical Health. All constructs had indirect effects on Perceived Physical Health through Negative Emotionality. The effects of a risky family environment appear to be enduring, negatively affecting one's adult religious life, emotionality, social interactions, and perceived health. Religious engagement, however, may counteract the damaging effects of early life stress.

Increasing overweight and obesity erodes engagement in one's neighborhood by women, but not men.

Science.gov (United States)

Schuster, Roseanne C; Han, Seung Yong; Brewis, Alexandra A; Wutich, Amber

2018-06-01

Obesity is socially stigmatized in the U.S., especially for women. Significant research has focused on the role that the social and built environments of neighborhoods play in shaping obesity. However, the role of obesity in shaping neighborhood social structure has been largely overlooked. We test the hypothesis that large body size inhibits an individual's engagement in his or her neighborhood. Our study objectives are to assess if (1) body size (body mass index) interacts with gender to predict engagement in one's neighborhood (neighborhood engagement) and (2) if bonding social capital interacts with gender to predict neighborhood engagement independent of body size. We used data collected from the cross-sectional 2011 Phoenix Area Social Survey (PASS), which systematically sampled residents across four neighborhood types (core urban, urban fringe, suburban, retirement) across the Phoenix Metopolitian Area. Survey data was analyzed using logistic regression for 804 participants, including 35% for whom missing data was computed using multiple imputation. We found that as body size increases, women-but not men-have reduced engagement in their neighborhood, independent of bonding social capital and other key covariates (objective 1). We did not observe the interaction between gender and bonding social capital associated with neighborhood engagement (objective 2). Prior scholarship suggests obesity clusters in neighborhoods due to processes of social, economic, and environmental disadvantage. This finding suggests bi-directionality: obesity could, in turn, undermine neighborhood engagement through the mechanism of weight stigma and discrimination.

Predicting physical activity energy expenditure in wheelchair users with a multisensor device.

Science.gov (United States)

Nightingale, T E; Walhin, J P; Thompson, D; Bilzon, J L J

2015-01-01

To assess the error in predicting physical activity energy expenditure (PAEE), using a multisensor device in wheelchair users, and to examine the efficacy of using an individual heart rate calibration (IC) method. 15 manual wheelchair users (36±10 years, 72±11 kg) completed 10 activities: resting, folding clothes, wheelchair propulsion on a 1% gradient (3456 and 7 km/h) and propulsion at 4 km/h (with an additional 8% of body mass, 2% and 3% gradient) on a motorised wheelchair treadmill. Criterion PAEE was measured using a computerised indirect calorimetry system. Participants wore a combined accelerometer and heart rate monitor (Actiheart). They also performed an incremental arm crank ergometry test to exhaustion which permitted retrospective individual calibration of the Actiheart for the activity protocol. Linear regression analysis was conducted between criterion (indirect calorimetry) and estimated PAEE from the Actiheart using the manufacturer's proprietary algorithms (group calibration, GC) or IC. Bland-Altman plots were used and mean absolute error was calculated to assess the agreement between criterion values and estimated PAEE. Predicted PAEE was significantly (p<0.01) correlated with criterion PAEE (GC, r=0.76 and IC, r=0.95). The absolute bias ±95% limits of agreement were 0.51±3.75 and -0.22±0.96 kcal/min for GC and IC, respectively. Mean absolute errors across the activity protocol were 51.4±38.9% using GC and 16.8±15.8% using IC. PAEE can be accurately and precisely estimated using a combined accelerometer and heart rate monitor device, with integration of an IC. Interindividual variance in cardiovascular function and response to exercise is high in this population. Therefore, in manual wheelchair users, we advocate the use of an IC when using the Actiheart to predict PAEE.

A risk-based microbiological criterion that uses the relative risk as the critical limit

DEFF Research Database (Denmark)

Andersen, Jens Kirk; Nørrung, Birgit; da Costa Alves Machado, Simone

2015-01-01

A risk-based microbiological criterion is described, that is based on the relative risk associated to the analytical result of a number of samples taken from a food lot. The acceptable limit is a specific level of risk and not a specific number of microorganisms, as in other microbiological...... criteria. The approach requires the availability of a quantitative microbiological risk assessment model to get risk estimates for food products from sampled food lots. By relating these food lot risk estimates to the mean risk estimate associated to a representative baseline data set, a relative risk...... estimate can be obtained. This relative risk estimate then can be compared with a critical value, defined by the criterion. This microbiological criterion based on a relative risk limit is particularly useful when quantitative enumeration data are available and when the prevalence of the microorganism...

Neutron shielding calculations in a proton therapy facility based on Monte Carlo simulations and analytical models: Criterion for selecting the method of choice

International Nuclear Information System (INIS)

Titt, U.; Newhauser, W. D.

2005-01-01

Proton therapy facilities are shielded to limit the amount of secondary radiation to which patients, occupational workers and members of the general public are exposed. The most commonly applied shielding design methods for proton therapy facilities comprise semi-empirical and analytical methods to estimate the neutron dose equivalent. This study compares the results of these methods with a detailed simulation of a proton therapy facility by using the Monte Carlo technique. A comparison of neutron dose equivalent values predicted by the various methods reveals the superior accuracy of the Monte Carlo predictions in locations where the calculations converge. However, the reliability of the overall shielding design increases if simulation results, for which solutions have not converged, e.g. owing to too few particle histories, can be excluded, and deterministic models are being used at these locations. Criteria to accept or reject Monte Carlo calculations in such complex structures are not well understood. An optimum rejection criterion would allow all converging solutions of Monte Carlo simulation to be taken into account, and reject all solutions with uncertainties larger than the design safety margins. In this study, the optimum rejection criterion of 10% was found. The mean ratio was 26, 62% of all receptor locations showed a ratio between 0.9 and 10, and 92% were between 1 and 100. (authors)

A termination criterion for parameter estimation in stochastic models in systems biology.

Science.gov (United States)

Zimmer, Christoph; Sahle, Sven

2015-11-01

Parameter estimation procedures are a central aspect of modeling approaches in systems biology. They are often computationally expensive, especially when the models take stochasticity into account. Typically parameter estimation involves the iterative optimization of an objective function that describes how well the model fits some measured data with a certain set of parameter values. In order to limit the computational expenses it is therefore important to apply an adequate stopping criterion for the optimization process, so that the optimization continues at least until a reasonable fit is obtained, but not much longer. In the case of stochastic modeling, at least some parameter estimation schemes involve an objective function that is itself a random variable. This means that plain convergence tests are not a priori suitable as stopping criteria. This article suggests a termination criterion suited to optimization problems in parameter estimation arising from stochastic models in systems biology. The termination criterion is developed for optimization algorithms that involve populations of parameter sets, such as particle swarm or evolutionary algorithms. It is based on comparing the variance of the objective function over the whole population of parameter sets with the variance of repeated evaluations of the objective function at the best parameter set. The performance is demonstrated for several different algorithms. To test the termination criterion we choose polynomial test functions as well as systems biology models such as an Immigration-Death model and a bistable genetic toggle switch. The genetic toggle switch is an especially challenging test case as it shows a stochastic switching between two steady states which is qualitatively different from the model behavior in a deterministic model. Copyright © 2015. Published by Elsevier Ireland Ltd.

Criterion-Referenced Values of Grip Strength and Usual Gait Speed Using Instrumental Activities of Daily Living Disability as the Criterion.

Science.gov (United States)

Lee, Meng-Chih; Hsu, Chih-Cheng; Tsai, Yi-Fen; Chen, Ching-Yu; Lin, Cheng-Chieh; Wang, Ching-Yi

Current evidence suggests that grip strength and usual gait speed (UGS) are important predictors of instrumental activities of daily living (IADL) disability. Knowing the optimum cut points of these tests for discriminating people with and without IADL disability could help clinicians or researchers to better interpret the test results and make medical decisions. The purpose of this study was to determine the cutoff values of grip strength and UGS for best discriminating community-dwelling older adults with and without IADL disability, separately for men and women, and to investigate their association with IADL disability. We conducted secondary data analysis on a national dataset collected in the Sarcopenia and Translational Aging Research in Taiwan (START). The data used in this study consisted of health data of 2420 community-dwelling older adults 65 years and older with no history of stroke and with complete data. IADL disability was defined as at least 1 IADL item scored as "need help" or "unable to perform." Receiver operating characteristics analysis was used to estimate the optimum grip strength and UGS cut points for best discriminating older adults with/without IADL disability. The association between each physical performance (grip strength and UGS) and IADL disability was assessed with odds ratios (ORs). With IADL disability as the criterion, the optimal cutoff values of grip strength were 28.7 kg for men and 16.0 kg for women, and those for UGS were 0.76 m/s for men and 0.66 m/s for women. The grip strength test showed satisfactory discriminant validity (area under the curve > 0.7) in men and a strong association with IADL disability (OR > 4). Our cut points using IADL disability as the criterion were close to those indicating frailty or sarcopenia. Our reported cutoffs can serve as criterion-referenced values, along with those previously determined using different indicators, and provide important landmarks on the performance continua of older adults

“INFLUENCE OF BASIC MOTOR ABILITIES AND CONOTIVE CRITERION ON RESULTS OF SUCCESS IN SOME SPORTS GAMES FOR STUDENTS OF TEACHING SCHOOL”

Directory of Open Access Journals (Sweden)

Midhat Mekić

2008-08-01

Full Text Available Upon the results of research it is possible to conclude that high level of influence of basic motor abilities and conotive criterion for successive results of sports games. Dominative predictions of values had conatice characteristic (A1,L17 and one test for judgment of explosiveness of lower extremities. For above mentioned results of this research, first of all, main values of defining hypothesis for further research, as well as promotion of education-teaching process of sports games in high schools.

Psychological Empowerment and Work Engagement as Predictors of Work Satisfaction: A Sample of Hotel Employees .

Directory of Open Access Journals (Sweden)

Daniel Moura

2015-06-01

Full Text Available With more organizations looking for employees who take initiative and respond creatively to the challenges of the job, engagement and psychological empowerment becomes important at both individual and organizational levels. Engaged employees are generally more satisfied with their work, committed and effective at work. According to the JDR model (Schaufeli and Bakker, 2004, engagement may be produced by two types of working conditions: job demands (i.e., role stress and job resources (i.e., psychological empowerment; self-efficacy. This study examines the role of psychological empowerment and work engagement as antecedents of job satisfaction. A cross sectional study using online questionnaires was conducted. The sample consisted of 152 Portuguese workers in hotels. Tourism is an important tool for profit and the Portuguese hotels are fundamental for the growth of the country. Employee satisfaction increases employee retention and increases productivity influencing the income / profits for hotels. Hierarchical multiple regressions analyses revealed that job satisfaction was significantly predicted by psychological empowerment and work engagement. Results support JDR model by showing that positive outcomes, such as job satisfaction, may be predicted by motivational process and job demands. On a practical level, JDR model provides a framework for understanding motivating workplaces and engaged and satisfied hotel employees.

Exploring DSM-5 criterion A in Acute Stress Disorder symptoms following natural disaster.

Science.gov (United States)

Lavenda, Osnat; Grossman, Ephraim S; Ben-Ezra, Menachem; Hoffman, Yaakov

2017-10-01

The present study examines the DSM-5 Acute Stress Disorder (ASD) diagnostic criteria of exposure, in the context of a natural disaster. The study is based on the reports of 1001 Filipinos following the aftermath of super typhoon Haiyan in 2013. Participants reported exposure to injury, psychological distress and ASD symptoms. Findings indicated the association of criterion A with the prevalence of meeting all other ASD diagnostic criteria and high psychological distress. The diagnostic properties of Criterion A are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Contributions of Work-Related Stress and Emotional Intelligence to Teacher Engagement: Additive and Interactive Effects.

Science.gov (United States)

Mérida-López, Sergio; Extremera, Natalio; Rey, Lourdes

2017-09-29

This study examined the additive and interactive effects of role stress and emotional intelligence for predicting engagement among 288 teachers. Emotional intelligence and engagement were positively associated. Role ambiguity and role conflict showed negative associations with vigor and dedication scores. The interaction of role ambiguity and emotional intelligence was significant in explaining engagement dimensions. Similar results were found considering overall teacher engagement. Emotional intelligence boosted engagement when the levels of role ambiguity were higher. Our findings suggest the need for future research examining the impact of job hindrances on the links between emotional intelligence and teachers' occupational well-being indicators. Finally, the implications for emotional intelligence training in education are discussed.

An advanced constitutive model in the sheet metal forming simulation: the Teodosiu microstructural model and the Cazacu Barlat yield criterion

International Nuclear Information System (INIS)

Alves, J.L.; Oliveira, M.C.; Menezes, L.F.

2004-01-01

Two constitutive models used to describe the plastic behavior of sheet metals in the numerical simulation of sheet metal forming process are studied: a recently proposed advanced constitutive model based on the Teodosiu microstructural model and the Cazacu Barlat yield criterion is compared with a more classical one, based on the Swift law and the Hill 1948 yield criterion. These constitutive models are implemented into DD3IMP, a finite element home code specifically developed to simulate sheet metal forming processes, which generically is a 3-D elastoplastic finite element code with an updated Lagrangian formulation, following a fully implicit time integration scheme, large elastoplastic strains and rotations. Solid finite elements and parametric surfaces are used to model the blank sheet and tool surfaces, respectively. Some details of the numerical implementation of the constitutive models are given. Finally, the theory is illustrated with the numerical simulation of the deep drawing of a cylindrical cup. The results show that the proposed advanced constitutive model predicts with more exactness the final shape (medium height and ears profile) of the formed part, as one can conclude from the comparison with the experimental results

An Analysis and Implementation of the Hidden Markov Model to Technology Stock Prediction

Directory of Open Access Journals (Sweden)

Nguyet Nguyen

2017-11-01

Full Text Available Future stock prices depend on many internal and external factors that are not easy to evaluate. In this paper, we use the Hidden Markov Model, (HMM, to predict a daily stock price of three active trading stocks: Apple, Google, and Facebook, based on their historical data. We first use the Akaike information criterion (AIC and Bayesian information criterion (BIC to choose the numbers of states from HMM. We then use the models to predict close prices of these three stocks using both single observation data and multiple observation data. Finally, we use the predictions as signals for trading these stocks. The criteria tests’ results showed that HMM with two states worked the best among two, three and four states for the three stocks. Our results also demonstrate that the HMM outperformed the naïve method in forecasting stock prices. The results also showed that active traders using HMM got a higher return than using the naïve forecast for Facebook and Google stocks. The stock price prediction method has a significant impact on stock trading and derivative hedging.

Early Stop Criterion from the Bootstrap Ensemble

DEFF Research Database (Denmark)

Hansen, Lars Kai; Larsen, Jan; Fog, Torben L.

1997-01-01

This paper addresses the problem of generalization error estimation in neural networks. A new early stop criterion based on a Bootstrap estimate of the generalization error is suggested. The estimate does not require the network to be trained to the minimum of the cost function, as required...... by other methods based on asymptotic theory. Moreover, in contrast to methods based on cross-validation which require data left out for testing, and thus biasing the estimate, the Bootstrap technique does not have this disadvantage. The potential of the suggested technique is demonstrated on various time...

Perception of economic crisis among Spanish nursing students: Its relation to burnout and engagement.

Science.gov (United States)

Manzano-García, Guadalupe; Montañés, Pilar; Megías, Jesús L

2017-05-01

The high levels of indebtedness and deficit of Spain's autonomous communities as a consequence of the national and European economic crisis have caused radical changes in the Spanish National Health Service. At the present time, the economic crisis is seriously affecting nurses in several European countries, and especially in Spain. The aim of this study was to analyse whether nursing students' perceptions of economic crisis influence their levels of burnout and engagement in relation to their studies. We have also tried to clarify the relationship of sociodemographic variables (age and gender) and personal control factors (self-efficacy, locus of control and success) with these factors. This was a transversal study based on descriptive and inferential statistical analysis. Analysis of the quantitative data was performed using Statistical Package for Social Sciences, IBM 19.0 (SPSS, 2010). 166 nursing students participated in the study, comprising 142 women and 24 men studying in Schools of Nursing in the North of Spain. They completed various questionnaires to gather information on sociodemographic variables and measure burnout, engagement, locus of control, expectations of success and perceptions of threat due to the economic crisis. Higher perception of economic crisis by the students is related to higher scores for burnout and lower scores for engagement. The scores for burnout were also positively predicted by external locus of control and negatively predicted by perception of self-efficacy. The age of participants is related to lower levels of burnout and higher levels of engagement. Finally, expectation of success also positively predicted the level of engagement. The results demonstrate the importance of the perceptions of the economic crisis on the development of burnout and engagement among nursing students. Copyright © 2017 Elsevier Ltd. All rights reserved.

Demands–abilities fit, work beliefs, meaningful work and engagement in nature-based jobs

Directory of Open Access Journals (Sweden)

Nellie de Crom

2018-03-01

Full Text Available Orientation: Meaningful work and personal engagement are important dimensions of flourishing of employees, especially when individuals work in challenging jobs. Research purpose: This study aimed to investigate the relationship between demands–abilities fit, work beliefs, meaningful work and engagement in individuals in nature-based jobs. Motivation for the study: Individuals working in nature often work under challenging circumstances without the necessary resources. A research gap exists regarding the effects of demands–abilities fit and work beliefs on meaningful work. It is also not clear how these antecedents and meaningful work will impact the engagement of individuals working in nature. Research approach, design and method: A cross-sectional survey was used with a convenience sample of 161 nature-based employees. Data were collected using a structured online questionnaire consisting of items from the demands–abilities fit scale, work–life questionnaire, work and meaning Inventory, work engagement scale and a biographical questionnaire. Main findings: Work beliefs (calling, career and job and demands–abilities fit predicted a large percentage of the variance in meaning making. Work beliefs (calling and job and demands–abilities fit also predicted a large percentage of the variance in greater good motivations. Demands–abilities fit and a calling work orientation indirectly affected work engagement via meaningful work. The scales which measured calling and job orientations showed insufficient discriminant validity in relation to the scales which measured positive meaning and work engagement. Practical and managerial implications: Managers should consider implementing interventions to affect the demands–abilities fit (through human resource management interventions and work beliefs of individuals working in nature (through job crafting. Promoting perceptions of meaningful work might contribute to higher personal engagement

Basis note in behalf of the development of a test criterion for the storage of radioactive waste

International Nuclear Information System (INIS)

1987-09-01

Aspects are described which may play a role in the development of a criterion for a final storage of radioactive waste. Such a criterion consists of a set of requirements concerning the quality of environment and public health, with which a proposal for the final storage of the waste has to be compared. The criterion should be able to give decisive answers regarding the acceptibility of a storage but should also be useful for the judgment of risk-analyses which are therefore necessary. 10 refs.; 9 figs.; 3 tabs

Perspective-taking increases willingness to engage in intergroup contact.

Science.gov (United States)

Wang, Cynthia S; Kenneth, Tai; Ku, Gillian; Galinsky, Adam D

2014-01-01

The current research explored whether perspective-taking increases willingness to engage in contact with stereotyped outgroup members. Across three studies, we find that perspective-taking increases willingness to engage in contact with negatively-stereotyped targets. In Study 1, perspective-takers sat closer to, whereas stereotype suppressors sat further from, a hooligan compared to control participants. In Study 2, individual differences in perspective-taking tendencies predicted individuals' willingness to engage in contact with a hooligan, having effects above and beyond those of empathic concern. Finally, Study 3 demonstrated that perspective-taking's effects on intergroup contact extend to the target's group (i.e., another homeless man), but not to other outgroups (i.e., a man of African descent). Consistent with other perspective-taking research, our findings show that perspective-taking facilitates the creation of social bonds by increasing contact with stereotyped outgroup members.

Children and video games: addiction, engagement, and scholastic achievement.

Science.gov (United States)

Skoric, Marko M; Teo, Linda Lay Ching; Neo, Rachel Lijie

2009-10-01

The aim of this study is to assess the relationship between video gaming habits and elementary school students' academic performance. More specifically, we seek to examine the usefulness of a distinction between addiction and high engagement and assess the predictive validity of these concepts in the context of scholastic achievement. Three hundred thirty-three children ages 8 to 12 years from two primary schools in Singapore were selected to participate in this study. A survey utilizing Danforth's Engagement-Addiction (II) scale and questions from DSM-IV was used to collect information from the schoolchildren, while their grades were obtained directly from their teachers. The findings indicate that addiction tendencies are consistently negatively related to scholastic performance, while no such relationship is found for either time spent playing games or for video game engagement. The implications of these findings are discussed.

Perspective-Taking Increases Willingness to Engage in Intergroup Contact

Science.gov (United States)

Wang, Cynthia S.; Kenneth, Tai; Ku, Gillian; Galinsky, Adam D.

2014-01-01

The current research explored whether perspective-taking increases willingness to engage in contact with stereotyped outgroup members. Across three studies, we find that perspective-taking increases willingness to engage in contact with negatively-stereotyped targets. In Study 1, perspective-takers sat closer to, whereas stereotype suppressors sat further from, a hooligan compared to control participants. In Study 2, individual differences in perspective-taking tendencies predicted individuals' willingness to engage in contact with a hooligan, having effects above and beyond those of empathic concern. Finally, Study 3 demonstrated that perspective-taking's effects on intergroup contact extend to the target's group (i.e., another homeless man), but not to other outgroups (i.e., a man of African descent). Consistent with other perspective-taking research, our findings show that perspective-taking facilitates the creation of social bonds by increasing contact with stereotyped outgroup members. PMID:24465648

The precautionary principle as a rational decision criterion; Foere var-prinsippet som rasjonelt beslutningsgrunnlag

Energy Technology Data Exchange (ETDEWEB)

Hovi, Jon

2001-12-01

The paper asks if the precautionary principle may be seen as a rational decision criterion. Six main questions are discussed. 1. Does the principle basically represent a particular set of political options or is it a genuine decision criterion? 2. If it is the latter, can it be reduced to any of the existing criteria for decision making under uncertainty? 3. In what kinds of situation is the principle applicable? 4. What is the relation between the precautionary principle and other principles for environmental regulation? 5. How plausible is the principle's claim that the burden of proof should be reversed? 6. Do the proponents of environmental regulation carry no burden of proof at all? A main conclusion is that, for now at least, the principle contains too many unclear elements to satisfy the requirements of precision and consistency that should reasonably be satisfied by a rational decision criterion. (author)

Engaging narratives evoke similar neural activity and lead to similar time perception.

Science.gov (United States)

Cohen, Samantha S; Henin, Simon; Parra, Lucas C

2017-07-04

It is said that we lose track of time - that "time flies" - when we are engrossed in a story. How does engagement with the story cause this distorted perception of time, and what are its neural correlates? People commit both time and attentional resources to an engaging stimulus. For narrative videos, attentional engagement can be represented as the level of similarity between the electroencephalographic responses of different viewers. Here we show that this measure of neural engagement predicted the duration of time that viewers were willing to commit to narrative videos. Contrary to popular wisdom, engagement did not distort the average perception of time duration. Rather, more similar brain responses resulted in a more uniform perception of time across viewers. These findings suggest that by capturing the attention of an audience, narrative videos bring both neural processing and the subjective perception of time into synchrony.

Development and validation of SEER (Seeking, Engaging with and Evaluating Research): a measure of policymakers' capacity to engage with and use research.

Science.gov (United States)

Brennan, Sue E; McKenzie, Joanne E; Turner, Tari; Redman, Sally; Makkar, Steve; Williamson, Anna; Haynes, Abby; Green, Sally E

2017-01-17

Capacity building strategies are widely used to increase the use of research in policy development. However, a lack of well-validated measures for policy contexts has hampered efforts to identify priorities for capacity building and to evaluate the impact of strategies. We aimed to address this gap by developing SEER (Seeking, Engaging with and Evaluating Research), a self-report measure of individual policymakers' capacity to engage with and use research. We used the SPIRIT Action Framework to identify pertinent domains and guide development of items for measuring each domain. Scales covered (1) individual capacity to use research (confidence in using research, value placed on research, individual perceptions of the value their organisation places on research, supporting tools and systems), (2) actions taken to engage with research and researchers, and (3) use of research to inform policy (extent and type of research use). A sample of policymakers engaged in health policy development provided data to examine scale reliability (internal consistency, test-retest) and validity (relation to measures of similar concepts, relation to a measure of intention to use research, internal structure of the individual capacity scales). Response rates were 55% (150/272 people, 12 agencies) for the validity and internal consistency analyses, and 54% (57/105 people, 9 agencies) for test-retest reliability. The individual capacity scales demonstrated adequate internal consistency reliability (alpha coefficients > 0.7, all four scales) and test-retest reliability (intra-class correlation coefficients > 0.7 for three scales and 0.59 for fourth scale). Scores on individual capacity scales converged as predicted with measures of similar concepts (moderate correlations of > 0.4), and confirmatory factor analysis provided evidence that the scales measured related but distinct concepts. Items in each of these four scales related as predicted to concepts in the measurement model derived

Empowering leaders optimize working conditions for engagement: a multilevel study.

Science.gov (United States)

Tuckey, Michelle R; Bakker, Arnold B; Dollard, Maureen F

2012-01-01

Using a multilevel framework, this study examined the role of empowering leadership at the group level by fire brigade captains in facilitating the individual level motivational processes that underpin work engagement in volunteer firefighters. Anonymous mail surveys were completed by 540 volunteer firefighters from 68 fire brigades and, separately, by 68 brigade captains. As predicted on the basis of the Job Demands-Resources model, increased levels of cognitive demands and cognitive resources partially mediated the relationship between empowering leadership and work engagement. In a three-way Leadership × Demands × Resources interaction, empowering leadership also had the effect of optimizing working conditions for engagement by strengthening the positive effect of a work context in which both cognitive demands and cognitive resources were high. Our findings shed light on a process through which leaders can empower workers and enhance well-being: via their influence on and interaction with the work environment. They also underscore the need to examine work engagement from a multilevel theoretical perspective.

Development of stress-modified fracture strain criterion for ductile fracture of API X65 steel

International Nuclear Information System (INIS)

Oh, Chang Kyun; Kim, Yun Jae; Park, Jin Moo; Kim, Woo Sik; Baek, Jong Hyun

2005-01-01

This paper presents a stress-modified fracture strain for API X65 steel used for gas pipeline, as a function of stress triaxiality. To determine the stress-modified fracture strain, tension test of bars with four different notch radii, made of API X65 steel, is firstly performed, from which true fracture strains are determined as a function of notch radius. Then detailed elastic-plastic, large strain Finite Element (FE) analyses are performed to estimate variations of stress triaxiality in the notched bars with load. Combining experimental with FE results provides the true fracture strain as a function of stress triaxiality, which is regarded as a criterion of ductile fracture. Application of the developed stress-modified fracture strain to failure prediction of gas pipes made of API X65 steel with various types of defects is discussed

Lifetime prediction of structures submitted to thermal fatigue loadings; Prediction de duree de vie de structures sous chargement de fatigue thermique

Energy Technology Data Exchange (ETDEWEB)

Amiable, S

2006-01-15

The aim of this work is to predict the lifetime of structures submitted to thermal fatigue loadings. This work lies within the studies undertaken by the CEA on the thermal fatigue problems from the french reactor of Civaux. In particular we study the SPLASH test: a specimen is heated continuously and cyclically cooled down by a water spray. This loading generates important temperature gradients in space and time and leads to the initiation and the propagation of a crack network. We propose a new thermo-mechanical model to simulate the SPLASH experiment and we propose a new fatigue criterion to predict the lifetime of the SPLASH specimen. We propose and compare several numerical models with various complexity to estimate the mechanical response of the SPLASH specimen. The practical implications of this work are the reevaluation of the hypothesis used in the French code RCC, which are used to simulate thermal shock and to interpret the results in terms of fatigue. This work leads to new perspectives on the mechanical interpretation of the fatigue criterion. (author)

A practical criterion of irreducibility of multi-loop Feynman integrals

International Nuclear Information System (INIS)

Baikov, P.A.

2006-01-01

A practical criterion for the irreducibility (with respect to integration by part identities) of a particular Feynman integral to a given set of integrals is presented. The irreducibility is shown to be related to the existence of stable (with zero gradient) points of a specially constructed polynomial

Warm and Supportive Parenting Can Discourage Offspring's Civic Engagement in the Transition to Adulthood.

Science.gov (United States)

Pavlova, Maria K; Silbereisen, Rainer K; Ranta, Mette; Salmela-Aro, Katariina

2016-11-01

It is widely believed that warm and supportive parenting fosters all kinds of prosocial behaviors in the offspring, including civic engagement. However, accumulating international evidence suggests that the effects of family support on civic engagement may sometimes be negative. To address this apparent controversy, we identified several scenarios for the negative effects of supportive parenting on youth civic engagement and tested them using four waves of data from the Finnish Educational Transitions Studies. They followed 1549 students (55 % female) from late adolescence into young adulthood, included both maternal (n = 231) and offspring reports of parental support, and assessed civic engagement in young adulthood. Control variables included socioeconomic status, other sociodemographic indicators, church belonging, personality traits, and earlier civic engagement. Higher maternal warmth and support and a stronger identification with the parental family in adolescence predicted offspring's lower political activism up to 10 years later. Perceived parental support in young adulthood predicted lower volunteering 2 years later. There were no significant effects on general organizational involvement (e.g., in student and hobby associations). None of the a priori scenarios that we identified from the literature appeared to explain the pattern of results satisfactorily. We put forth cultural and life stage explanations of our findings.

Novel criterion for formation of metastable phase from undercooled melt

International Nuclear Information System (INIS)

Kuribayashi, Kazuhiko; Nagashio, Kosuke; Niwata, Kenji; Kumar, M.S. Vijaya; Hibiya, Taketoshi

2007-01-01

Undercooling a melt facilitates the preferential nucleation of a metastable phase. In the present study, the formation of metastable phases from undercooled melts was considered from the viewpoint of the competitive nucleation criterion. The classical nucleation theory shows us that the most critical factor for forming a critical nucleus is the interface free energy σ. Furthermore, Spaepen's negentropic model on σ generated the role of the scaling factor α that depends on the polyhedral order in the liquid and solid phases prominent in simple liquids such as the melt of monoatomic metals. In ionic materials such as oxides, however, in which oxygen polyhedrons including a cation at their center are the structural units both in the solid and liquid phases, the entropy of fusion, rather than α, can be expected to become dominant in the determination of σ. In accordance with this idea, using REFeO 3 as the model material (where RE denotes rare-earth elements) the entropy-undercooling regime criterion was proposed and verified

A new diagnostic accuracy measure and cut-point selection criterion.

Science.gov (United States)

Dong, Tuochuan; Attwood, Kristopher; Hutson, Alan; Liu, Song; Tian, Lili

2017-12-01

Most diagnostic accuracy measures and criteria for selecting optimal cut-points are only applicable to diseases with binary or three stages. Currently, there exist two diagnostic measures for diseases with general k stages: the hypervolume under the manifold and the generalized Youden index. While hypervolume under the manifold cannot be used for cut-points selection, generalized Youden index is only defined upon correct classification rates. This paper proposes a new measure named maximum absolute determinant for diseases with k stages ([Formula: see text]). This comprehensive new measure utilizes all the available classification information and serves as a cut-points selection criterion as well. Both the geometric and probabilistic interpretations for the new measure are examined. Power and simulation studies are carried out to investigate its performance as a measure of diagnostic accuracy as well as cut-points selection criterion. A real data set from Alzheimer's Disease Neuroimaging Initiative is analyzed using the proposed maximum absolute determinant.

A Literature Review: Website Design and User Engagement.

Science.gov (United States)

Garett, Renee; Chiu, Jason; Zhang, Ly; Young, Sean D

2016-07-01

Proper design has become a critical element needed to engage website and mobile application users. However, little research has been conducted to define the specific elements used in effective website and mobile application design. We attempt to review and consolidate research on effective design and to define a short list of elements frequently used in research. The design elements mentioned most frequently in the reviewed literature were navigation, graphical representation, organization, content utility, purpose, simplicity, and readability. We discuss how previous studies define and evaluate these seven elements. This review and the resulting short list of design elements may be used to help designers and researchers to operationalize best practices for facilitating and predicting user engagement.

Distinct anatomical correlates of discriminability and criterion setting in verbal recognition memory revealed by lesion-symptom mapping

NARCIS (Netherlands)

Biesbroek, J Matthijs; van Zandvoort, Martine J E; Kappelle, L Jaap; Schoo, Linda; Kuijf, Hugo J; Velthuis, Birgitta K; Biessels, Geert Jan; Postma, Albert

2014-01-01

Recognition memory, that is, the ability to judge whether an item has been previously encountered in a particular context, depends on two factors: discriminability and criterion setting. Discriminability draws on memory processes while criterion setting (i.e., the application of a threshold

Distinct anatomical correlates of discriminability and criterion setting in verbal recognition memory revealed by lesion-symptom mapping

NARCIS (Netherlands)

Biesbroek, J. Matthijs; van Zandvoort, Martine J E; Kappelle, L. Jaap; Schoo, Linda; Kuijf, Hugo J.; Velthuis, BK; Biessels, Geert Jan; Postma, Albert

2015-01-01

Recognition memory, that is, the ability to judge whether an item has been previously encountered in a particular context, depends on two factors: discriminability and criterion setting. Discriminability draws on memory processes while criterion setting (i.e., the application of a threshold

Cross-Validation of Aerobic Capacity Prediction Models in Adolescents.

Science.gov (United States)

Burns, Ryan Donald; Hannon, James C; Brusseau, Timothy A; Eisenman, Patricia A; Saint-Maurice, Pedro F; Welk, Greg J; Mahar, Matthew T

2015-08-01

Cardiorespiratory endurance is a component of health-related fitness. FITNESSGRAM recommends the Progressive Aerobic Cardiovascular Endurance Run (PACER) or One mile Run/Walk (1MRW) to assess cardiorespiratory endurance by estimating VO2 Peak. No research has cross-validated prediction models from both PACER and 1MRW, including the New PACER Model and PACER-Mile Equivalent (PACER-MEQ) using current standards. The purpose of this study was to cross-validate prediction models from PACER and 1MRW against measured VO2 Peak in adolescents. Cardiorespiratory endurance data were collected on 90 adolescents aged 13-16 years (Mean = 14.7 ± 1.3 years; 32 girls, 52 boys) who completed the PACER and 1MRW in addition to a laboratory maximal treadmill test to measure VO2 Peak. Multiple correlations among various models with measured VO2 Peak were considered moderately strong (R = .74-0.78), and prediction error (RMSE) ranged from 5.95 ml·kg⁻¹,min⁻¹ to 8.27 ml·kg⁻¹.min⁻¹. Criterion-referenced agreement into FITNESSGRAM's Healthy Fitness Zones was considered fair-to-good among models (Kappa = 0.31-0.62; Agreement = 75.5-89.9%; F = 0.08-0.65). In conclusion, prediction models demonstrated moderately strong linear relationships with measured VO2 Peak, fair prediction error, and fair-to-good criterion referenced agreement with measured VO2 Peak into FITNESSGRAM's Healthy Fitness Zones.

Incorporating single-side sparing in models for predicting parotid dose sparing in head and neck IMRT

International Nuclear Information System (INIS)

Yuan, Lulin; Wu, Q. Jackie; Yin, Fang-Fang; Yoo, David; Jiang, Yuliang; Ge, Yaorong

2014-01-01

Purpose: Sparing of single-side parotid gland is a common practice in head-and-neck (HN) intensity modulated radiation therapy (IMRT) planning. It is a special case of dose sparing tradeoff between different organs-at-risk. The authors describe an improved mathematical model for predicting achievable dose sparing in parotid glands in HN IMRT planning that incorporates single-side sparing considerations based on patient anatomy and learning from prior plan data. Methods: Among 68 HN cases analyzed retrospectively, 35 cases had physician prescribed single-side parotid sparing preferences. The single-side sparing model was trained with cases which had single-side sparing preferences, while the standard model was trained with the remainder of cases. A receiver operating characteristics (ROC) analysis was performed to determine the best criterion that separates the two case groups using the physician's single-side sparing prescription as ground truth. The final predictive model (combined model) takes into account the single-side sparing by switching between the standard and single-side sparing models according to the single-side sparing criterion. The models were tested with 20 additional cases. The significance of the improvement of prediction accuracy by the combined model over the standard model was evaluated using the Wilcoxon rank-sum test. Results: Using the ROC analysis, the best single-side sparing criterion is (1) the predicted median dose of one parotid is higher than 24 Gy; and (2) that of the other is higher than 7 Gy. This criterion gives a true positive rate of 0.82 and a false positive rate of 0.19, respectively. For the bilateral sparing cases, the combined and the standard models performed equally well, with the median of the prediction errors for parotid median dose being 0.34 Gy by both models (p = 0.81). For the single-side sparing cases, the standard model overestimates the median dose by 7.8 Gy on average, while the predictions by the combined

Engaged to Learn Ways of Engaging ESL Learners

Directory of Open Access Journals (Sweden)

Brian Tomlinson

2010-01-01

Full Text Available In this paper I am going to argue that our most important role as language teachers is to provide potentially engaging materials for our learners and then to make use of them in optimally engaging ways. If we do not engage our learners most of the time no amount of exposure, teaching, practice or use of the language will help them to achieve sufficient language acquisition and development.

Contributions of Work-Related Stress and Emotional Intelligence to Teacher Engagement: Additive and Interactive Effects

Directory of Open Access Journals (Sweden)

Sergio Mérida-López

2017-09-01

Full Text Available This study examined the additive and interactive effects of role stress and emotional intelligence for predicting engagement among 288 teachers. Emotional intelligence and engagement were positively associated. Role ambiguity and role conflict showed negative associations with vigor and dedication scores. The interaction of role ambiguity and emotional intelligence was significant in explaining engagement dimensions. Similar results were found considering overall teacher engagement. Emotional intelligence boosted engagement when the levels of role ambiguity were higher. Our findings suggest the need for future research examining the impact of job hindrances on the links between emotional intelligence and teachers’ occupational well-being indicators. Finally, the implications for emotional intelligence training in education are discussed.

Contributions of Work-Related Stress and Emotional Intelligence to Teacher Engagement: Additive and Interactive Effects

Science.gov (United States)

2017-01-01

This study examined the additive and interactive effects of role stress and emotional intelligence for predicting engagement among 288 teachers. Emotional intelligence and engagement were positively associated. Role ambiguity and role conflict showed negative associations with vigor and dedication scores. The interaction of role ambiguity and emotional intelligence was significant in explaining engagement dimensions. Similar results were found considering overall teacher engagement. Emotional intelligence boosted engagement when the levels of role ambiguity were higher. Our findings suggest the need for future research examining the impact of job hindrances on the links between emotional intelligence and teachers’ occupational well-being indicators. Finally, the implications for emotional intelligence training in education are discussed. PMID:28961218

An adaptive pruning algorithm for the discrete L-curve criterion

DEFF Research Database (Denmark)

Hansen, Per Christian; Jensen, Toke Koldborg; Rodriguez, Giuseppe

2007-01-01

We describe a robust and adaptive implementation of the L-curve criterion, i.e., for locating the corner of a discrete L-curve consisting of a log-log plot of corresponding residual and solution norms of regularized solutions from a method with a discrete regularization parameter (such as truncated...

Numerical and Experimental Validation of a New Damage Initiation Criterion

NARCIS (Netherlands)

Sadhinoch, M.; Atzema, E.H.; Perdahcioglu, E.S.; Van Den Boogaard, A.H.

2017-01-01

Most commercial finite element software packages, like Abaqus, have a built-in coupled damage model where a damage evolution needs to be defined in terms of a single fracture energy value for all stress states. The Johnson-Cook criterion has been modified to be Lode parameter dependent and this

Authentic leadership of preceptors: predictor of new graduate nurses' work engagement and job satisfaction.

Science.gov (United States)

Giallonardo, Lisa M; Wong, Carol A; Iwasiw, Carroll L

2010-11-01

To examine the relationships between new graduate nurses' perceptions of preceptor authentic leadership, work engagement and job satisfaction. During a time when the retention of new graduate nurses is of the upmost importance, the reliance on preceptors to facilitate the transition of new graduate nurses is paramount. A predictive non-experimental survey design was used to examine the relationships between study variables. The final sample consisted of 170 randomly selected Registered Nurses (RNs) with authentic leadership and work engagement. Furthermore, work engagement was found to partially mediate the relationship between authentic leadership of preceptors and engagement of new graduate nurses. New graduate nurses paired with preceptors who demonstrate high levels of authentic leadership feel more engaged and are more satisfied. Engagement is an important mechanism by which authentic leadership affects job satisfaction. Managers must be aware of the role preceptors' authentic leadership plays in promoting work engagement and job satisfaction of new nurses. © 2010 The Authors. Journal compilation © 2010 Blackwell Publishing Ltd.

The impact of past and present preferences on stimulus engagement in nursing home residents with dementia.

Science.gov (United States)

Cohen-Mansfield, Jiska; Marx, Marcia S; Thein, Khin; Dakheel-Ali, Maha

2010-01-01

We examined engagement with stimuli in 193 nursing home residents with dementia. We hypothesized that activities and stimuli based on a person's past and current preferences would result in more engagement than other activities/stimuli. The expanded version of the self-identity questionnaire [Cohen-Mansfield, J., Golander, H. & Arheim, G. (2000)] was used to determine participants' past/present interests (as reported by relatives) in the following areas: art, music, babies, pets, reading, television, and office work. We utilized the observational measurement of engagement (Cohen-Mansfield, J., Dakheel-Ali, M., & Marx, M.S. (2009). Analysis revealed that residents with current interests in music, art, and pets were more engaged by stimuli that reflect these interests than residents without these interests. Our findings demonstrate the utility of determining a person's preferences for stimuli in order to predict responsiveness. Lack of prediction for some stimuli may reflect differences between past preferences and activities that are feasible in the present.

Community Health Workers Promote Civic Engagement and Organizational Capacity to Impact Policy.

Science.gov (United States)

Sabo, Samantha; Flores, Melissa; Wennerstrom, Ashley; Bell, Melanie L; Verdugo, Lorena; Carvajal, Scott; Ingram, Maia

2017-12-01

Community health workers (CHW) have historically served to link structurally vulnerable populations to broad support systems. Emerging evidence suggests that CHWs engage in various forms of advocacy to promote policy and systems change. We assessed the impact of CHW community advocacy on community change, defined as civic engagement, organizational capacity and policy and systems change. Data are drawn from the 2014 National Community Health Worker Advocacy Survey (N = 1776) aimed to identify the state of the CHW profession, and their impact on health disparities through community advocacy and policy engagement. Our primary analysis used multiple linear regression to assess the association between CHW advocacy and community change. As predicted, there was a significant, positive association between CHW advocacy and change in community conditions. Additionally, both adjusted and sensitivity models had similar standardized beta estimates for advocacy, and adjusted R 2 statistics. CHW advocacy predicts positive change in community conditions and further advances the CHW Community Advocacy Framework designed to support and monitor CHW community advocacy to reduce health disparities through advocacy and policy change.

Turnover in health care: the mediating effects of employee engagement.

Science.gov (United States)

Collini, Stevie A; Guidroz, Ashley M; Perez, Lisa M

2015-03-01

This study aimed to understand the interaction between interpersonal respect, diversity climate, mission fulfilment and engagement to better predict turnover in health care. Registered nurse turnover has averaged 14% and current nursing shortages are expected to spread. Few studies have studied employee engagement as a mediator between organisational context and turnover. Study participants were employees working within 185 departments across ten hospitals within a large healthcare organisation in the USA. Although a total of 5443 employees work in these departments, employee opinion survey responses were aggregated by department before being linked to turnover rates gathered from company records. Engagement fully mediated the relationship between respect and turnover and the relationship between mission fulfilment and turnover. Diversity climate was not related to turnover. Turnover in health care poses a significant threat to the mission of creating a healing environment for patients and these results demonstrate that workplace respect and connection to the mission affect turnover by decreasing engagement. The findings demonstrated that to increase engagement, and improve turnover rates in health care, it would be beneficial for organisations, and nurse management to focus on improving mission fulfilment and interpersonal relationships. © 2013 John Wiley & Sons Ltd.

New Quality Assessment Criterion of AlSi5Cu1 Alloy

Directory of Open Access Journals (Sweden)

M. Wierzbińska

2007-07-01

Full Text Available The paper presents the discussion of the results of mechanical testing for aluminium foundry alloy AlSi5Cu1Mg for high-loaded machine elements. Values of yield strength (Rp0.2, tensile strength (Rm, elongation(A5 and hardness (HB are usually considered as the primary quality assessment criterion for a manufacturing process. It was concluded, that this criterion, A5 index particularly, is unsatisfactory to estimate the plasticity of the alloy and its crack resistance in the presence of sharp-pointed stress concentrators or microcracks. More adequate parameter is plane strain fracture toughness KIc. However, size of the samples appeared to be twice as large as would be needed to fulfill requirements of test conditions, and the test itself is laborious and time-consuming that it becomes impractical as a acceptance test. Therefore, substitute test for quality assessment – determination of tensile strength in the presence of a sharp notch kmR was applied. The comparative analysis of kmR/Rp0.2 ratio, as a more enhanced fatigue resistance criterion than kmR and plane strain fracture toughness KIc of the alloy was performed. It was assumed that kmR/Rp0.2 parameter has good correlation with the critical stress intensity factor KIc Thus, under manufacturing process conditions, being unable to carry out KIc test, it may be successfully replaced by kmR test.

The limits of the Bohm criterion in collisional plasmas

International Nuclear Information System (INIS)

Valentini, H.-B.; Kaiser, D.

2015-01-01

The sheath formation within a low-pressure collisional plasma is analysed by means of a two-fluid model. The Bohm criterion takes into account the effects of the electric field and the inertia of the ions. Numerical results yield that these effects contribute to the space charge formation, only, if the collisionality is lower than a relatively small threshold. It follows that a lower and an upper limit of the drift speed of the ions exist where the effects treated by Bohm can form a sheath. This interval becomes narrower as the collisionality increases and vanishes at the mentioned threshold. Above the threshold, the sheath is mainly created by collisions and the ionisation. Under these conditions, the sheath formation cannot be described by means of Bohm like criteria. In a few references, a so-called upper limit of the Bohm criterion is stated for collisional plasmas where the momentum equation of the ions is taken into account, only. However, the present paper shows that this limit results in an unrealistically steep increase of the space charge density towards the wall, and, therefore, it yields no useful limit of the Bohm velocity

Stress appraisal, coping, and work engagement among police recruits: an exploratory study.

Science.gov (United States)

Kaiseler, Mariana; Queirós, Cristina; Passos, Fernando; Sousa, Pedro

2014-04-01

This study investigated the influence of stress appraisal and coping on work engagement levels (Absorption, Vigour, and Dedication) of police recruits. Participants were 387 men, ages 20 to 33 yr. (M = 24.1, SD = 2.4), in their last month of academy training before becoming police officers. Partially in support of predictions, work engagement was associated with Stressor control perceived, but not Stress intensity experienced over a self-selected stressor. Although the three dimensions of work engagement were explained by Stressor control and coping, Absorption was the dimension better explained by these variables. Police recruits reporting higher Absorption, Vigour, and Dedication reported using more Active coping and less Behavioural disengagement. Results showed that stress appraisal and coping are important variables influencing work engagement among police recruits. Findings suggested that future applied interventions fostering work engagement among police recruits should reinforce perceptions of control over a stressor as well as Active coping strategies.

Theoretical modeling of CHF for near-saturated pool boiling and flow boiling from short heaters using the interfacial lift-off criterion

International Nuclear Information System (INIS)

Mudawar, I.; Galloway, J.E.; Gersey, C.O.

1995-01-01

Pool boiling and flow boiling were examined for near-saturated bulk conditions in order to determine the critical heat flux (CHF) trigger mechanism for each. Photographic studies of the wall region revealed features common to both situations. At fluxes below CHF, the vapor coalesces into a wavy layer which permits wetting only in wetting fronts, the portions of the liquid-vapor interface which contact the wall as a result of the interfacial waviness. Close examination of the interfacial features revealed the waves are generated from the lower edge of the heater in pool boiling and the heater's upstream region in flow boiling. Wavelengths follow predictions based upon the Kelvin-Helmholtz instability criterion. Critical heat flux in both cases occurs when the pressure force exerted upon the interface due to interfacial curvature, which tends to preserve interfacial contact with the wall prior to CHF, is overcome by the momentum of vapor at the site of the first wetting front, causing the interface to lift away from the wall. It is shown this interfacial lift-off criterion facilitates accurate theoretical modeling of CHF in pool boiling and in flow boiling in both straight and curved channels

Theoretical modeling of CHF for near-saturated pool boiling and flow boiling from short heaters using the interfacial lift-off criterion

Energy Technology Data Exchange (ETDEWEB)

Mudawar, I.; Galloway, J.E.; Gersey, C.O. [Purdue Univ., West Lafayette, IN (United States)] [and others

1995-12-31

Pool boiling and flow boiling were examined for near-saturated bulk conditions in order to determine the critical heat flux (CHF) trigger mechanism for each. Photographic studies of the wall region revealed features common to both situations. At fluxes below CHF, the vapor coalesces into a wavy layer which permits wetting only in wetting fronts, the portions of the liquid-vapor interface which contact the wall as a result of the interfacial waviness. Close examination of the interfacial features revealed the waves are generated from the lower edge of the heater in pool boiling and the heater`s upstream region in flow boiling. Wavelengths follow predictions based upon the Kelvin-Helmholtz instability criterion. Critical heat flux in both cases occurs when the pressure force exerted upon the interface due to interfacial curvature, which tends to preserve interfacial contact with the wall prior to CHF, is overcome by the momentum of vapor at the site of the first wetting front, causing the interface to lift away from the wall. It is shown this interfacial lift-off criterion facilitates accurate theoretical modeling of CHF in pool boiling and in flow boiling in both straight and curved channels.

Geometric steering criterion for two-qubit states

Science.gov (United States)

Yu, Bai-Chu; Jia, Zhih-Ahn; Wu, Yu-Chun; Guo, Guang-Can

2018-01-01

According to the geometric characterization of measurement assemblages and local hidden state (LHS) models, we propose a steering criterion which is both necessary and sufficient for two-qubit states under arbitrary measurement sets. A quantity is introduced to describe the required local resources to reconstruct a measurement assemblage for two-qubit states. We show that the quantity can be regarded as a quantification of steerability and be used to find out optimal LHS models. Finally we propose a method to generate unsteerable states, and construct some two-qubit states which are entangled but unsteerable under all projective measurements.