Effect of scaffolding on helping introductory physics students solve quantitative problems involving strong alternative conceptions

Science.gov (United States)

Lin, Shih-Yin; Singh, Chandralekha

2015-12-01

It is well known that introductory physics students often have alternative conceptions that are inconsistent with established physical principles and concepts. Invoking alternative conceptions in the quantitative problem-solving process can derail the entire process. In order to help students solve quantitative problems involving strong alternative conceptions correctly, appropriate scaffolding support can be helpful. The goal of this study is to examine how different scaffolding supports involving analogical problem-solving influence introductory physics students' performance on a target quantitative problem in a situation where many students' solution process is derailed due to alternative conceptions. Three different scaffolding supports were designed and implemented in calculus-based and algebra-based introductory physics courses involving 410 students to evaluate the level of scaffolding needed to help students learn from an analogical problem that is similar in the underlying principles involved but for which the problem-solving process is not derailed by alternative conceptions. We found that for the quantitative problem involving strong alternative conceptions, simply guiding students to work through the solution of the analogical problem first was not enough to help most students discern the similarity between the two problems. However, if additional scaffolding supports that directly helped students examine and repair their knowledge elements involving alternative conceptions were provided, e.g., by guiding students to contemplate related issues and asking them to solve the targeted problem on their own first before learning from the analogical problem provided, students were more likely to discern the underlying similarities between the problems and avoid getting derailed by alternative conceptions when solving the targeted problem. We also found that some scaffolding supports were more effective in the calculus-based course than in the algebra

Adolescents' Viewing of Suicide-Related Web Content and Psychological Problems: Differentiating the Roles of Cyberbullying Involvement.

Science.gov (United States)

Görzig, Anke

2016-08-01

Possible links of cyberbullying with suicide and psychological problems have recently received considerable attention. Suicide-related behaviors have also been linked with viewing of associated web content. Studies on traditional bullying indicate that the roles of bullying involvement (bullies, victims, and bully-victims) matter in terms of associations with specific suicide-related behaviors and psychological problems. Yet, related research in the area of cyberbullying is lacking. The current study investigates the association of cyberbullying roles with viewing of specific suicide-related web content and psychological problems. Data from N = 19,406 (50 percent girls) 11-16-year-olds (M = 13.54, SD = 1.68) of a representative sample of Internet-using children in Europe were analyzed. Self-reports were obtained for cyberbullying role, viewing of web content related to self-harm, and suicide, as well as the emotional, peer, and conduct problem subscales of the Strengths and Difficulties Questionnaire (SDQ). Multinomial logistic regression analyses revealed that compared with those not involved in cyberbullying, viewing of web content related to suicide was higher for cybervictims and cyberbully-victims, but not for cyberbullies. Viewing of web content related to self-harm was higher for all cyberbullying roles, especially for cyberbully-victims. Rates of emotional problems were higher among cybervictims and cyberbully-victims, rates of peer problems were higher for cybervictims, and rates of conduct problems were higher for all cyberbullying roles. Moreover, the links between cyberbullying role and viewing of suicide-related web content were independent of psychological problems. The results can be useful to more precisely target efforts toward the specific problems of each cyberbullying role. The outcomes on viewing of web content also indicate an opportunity to enhance the presence of health service providers on Internet platforms.

Nonlinear radiation transport problems involving widely varying mean free paths

International Nuclear Information System (INIS)

Chapline, G. Jr.; Wood, L.

1976-01-01

In this report a method is given for modifying the Monte-Carlo approach so that one can accurately treat problems that involve both large and small mean free paths. This method purports to offer the advantages of the general Monte Carlo technique as far as relatively great accuracy of simulation of microscopic physical phenomena is concerned, and the advantage of a diffusion theory approach as far as decent time steps in thick problems are concerned; it does suffer from something of the statistical fluctuation problems of the Monte Carlo, although in analytically attenuated and modified form

Father involvement moderates the effect of maternal depression during a child's infancy on child behavior problems in kindergarten.

Science.gov (United States)

Mezulis, Amy H; Hyde, Janet Shibley; Clark, Roseanne

2004-12-01

This research investigated whether father involvement in infancy may reduce or exacerbate the well-established adverse effect of maternal depression during a child's infancy on behavior problems in childhood. In a community sample (N = 350), the authors found that fathers' self-reported parenting styles interacted with the amount of time fathers spent caring for their infants to moderate the longitudinal effect of maternal depression during the child's infancy on children's internalizing, but not externalizing, behaviors. Low to medium amounts of high-warmth father involvement and high amounts of medium- or high-control father involvement at this time were associated with lower child internalizing behaviors. Paternal depression during a child's infancy exacerbated the effect of maternal depression, but this moderating effect was limited to depressed fathers spending medium to high amounts of time caring for their infants. Results emphasize the moderating role fathers may play in reducing or exacerbating the adverse long-term effects of maternal depression during a child's infancy on later child behavior problems. ((c) 2004 APA, all rights reserved).

Adaptive sampling method in deep-penetration particle transport problem

International Nuclear Information System (INIS)

Wang Ruihong; Ji Zhicheng; Pei Lucheng

2012-01-01

Deep-penetration problem has been one of the difficult problems in shielding calculation with Monte Carlo method for several decades. In this paper, a kind of particle transport random walking system under the emission point as a sampling station is built. Then, an adaptive sampling scheme is derived for better solution with the achieved information. The main advantage of the adaptive scheme is to choose the most suitable sampling number from the emission point station to obtain the minimum value of the total cost in the process of the random walk. Further, the related importance sampling method is introduced. Its main principle is to define the importance function due to the particle state and to ensure the sampling number of the emission particle is proportional to the importance function. The numerical results show that the adaptive scheme under the emission point as a station could overcome the difficulty of underestimation of the result in some degree, and the adaptive importance sampling method gets satisfied results as well. (authors)

Chance constrained problems: penalty reformulation and performance of sample approximation technique

Czech Academy of Sciences Publication Activity Database

Branda, Martin

2012-01-01

Roč. 48, č. 1 (2012), s. 105-122 ISSN 0023-5954 R&D Projects: GA ČR(CZ) GBP402/12/G097 Institutional research plan: CEZ:AV0Z10750506 Keywords : chance constrained problems * penalty functions * asymptotic equivalence * sample approximation technique * investment problem Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.619, year: 2012 http://library.utia.cas.cz/separaty/2012/E/branda-chance constrained problems penalty reformulation and performance of sample approximation technique.pdf

Solving probabilistic inverse problems rapidly with prior samples

NARCIS (Netherlands)

Käufl, Paul; Valentine, Andrew P.; de Wit, Ralph W.; Trampert, Jeannot

2016-01-01

Owing to the increasing availability of computational resources, in recent years the probabilistic solution of non-linear, geophysical inverse problems by means of sampling methods has become increasingly feasible. Nevertheless, we still face situations in which a Monte Carlo approach is not

Testing Homogeneity in a Semiparametric Two-Sample Problem

Directory of Open Access Journals (Sweden)

Yukun Liu

2012-01-01

Full Text Available We study a two-sample homogeneity testing problem, in which one sample comes from a population with density f(x and the other is from a mixture population with mixture density (1−λf(x+λg(x. This problem arises naturally from many statistical applications such as test for partial differential gene expression in microarray study or genetic studies for gene mutation. Under the semiparametric assumption g(x=f(xeα+βx, a penalized empirical likelihood ratio test could be constructed, but its implementation is hindered by the fact that there is neither feasible algorithm for computing the test statistic nor available research results on its theoretical properties. To circumvent these difficulties, we propose an EM test based on the penalized empirical likelihood. We prove that the EM test has a simple chi-square limiting distribution, and we also demonstrate its competitive testing performances by simulations. A real-data example is used to illustrate the proposed methodology.

The impact of gambling advertising: Problem gamblers report stronger impacts on involvement, knowledge, and awareness than recreational gamblers.

Science.gov (United States)

Hanss, Daniel; Mentzoni, Rune A; Griffiths, Mark D; Pallesen, Ståle

2015-06-01

Although there is a general lack of empirical evidence that advertising influences gambling participation, the regulation of gambling advertising is hotly debated among academic researchers, treatment specialists, lobby groups, regulators, and policymakers. This study contributes to the ongoing debate by investigating perceived impacts of gambling advertising in a sample of gamblers drawn from the general population in Norway (n = 6,034). Three dimensions of advertising impacts were identified, representing perceived impacts on (a) gambling-related attitudes, interest, and behavior ("involvement"); (b) knowledge about gambling options and providers ("knowledge"); and (c) the degree to which people are aware of gambling advertising ("awareness"). Overall, impacts were strongest for the knowledge dimension, and, for all 3 dimensions, the impact increased with level of advertising exposure. Those identified as problem gamblers in the sample (n = 57) reported advertising impacts concerning involvement more than recreational gamblers, and this finding was not attributable to differences in advertising exposure. Additionally, younger gamblers reported stronger impacts on involvement and knowledge but were less likely to agree that they were aware of gambling advertising than older gamblers. Male gamblers were more likely than female gamblers to report stronger impacts on both involvement and knowledge. These findings are discussed with regard to existing research on gambling advertising as well as their implications for future research and policy-making. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Problem and Pathological Gambling in a Sample of Casino Patrons

OpenAIRE

Fong, Timothy W.; Campos, Michael D.; Brecht, Mary-Lynn; Davis, Alice; Marco, Adrienne; Pecanha, Viviane; Rosenthal, Richard J.

2010-01-01

Relatively few studies have examined gambling problems among individuals in a casino setting. The current study sought to examine the prevalence of gambling problems among a sample of casino patrons and examine alcohol and tobacco use, health status, and quality of life by gambling problem status. To these ends, 176 casino patrons were recruited by going to a Southern California casino and requesting that they complete an anonymous survey. Results indicated the following lifetime rates for at...

On the problems of PPS sampling in multi-character surveys ...

African Journals Online (AJOL)

This paper, which is on the problems of PPS sampling in multi-character surveys, compares the efficiency of some estimators used in PPSWR sampling for multiple characteristics. From a superpopulation model, we computed the expected variances of the different estimators for each of the first two finite populations ...

Secondary School Students' Reasoning about Conditional Probability, Samples, and Sampling Procedures

Science.gov (United States)

Prodromou, Theodosia

2016-01-01

In the Australian mathematics curriculum, Year 12 students (aged 16-17) are asked to solve conditional probability problems that involve the representation of the problem situation with two-way tables or three-dimensional diagrams and consider sampling procedures that result in different correct answers. In a small exploratory study, we…

Association between Parental Involvement in School and Child Conduct, Social, and Internalizing Problems: Teacher Report

Science.gov (United States)

Kirkhaug, Bente; Drugli, May Britt; Klockner, Christian A.; Morch, Willy-Tore

2013-01-01

The present study examined the factor structure of the Teacher Involvement Questionnaire (Involve-T) by means of exploratory factor analysis and examined the association between children's socio-emotional and behavioural problems and teacher-reported parental involvement in school, using structural equation modelling. The study was conducted with…

Problem and pathological gambling in a sample of casino patrons.

Science.gov (United States)

Fong, Timothy W; Campos, Michael D; Brecht, Mary-Lynn; Davis, Alice; Marco, Adrienne; Pecanha, Viviane; Rosenthal, Richard J

2011-03-01

Relatively few studies have examined gambling problems among individuals in a casino setting. The current study sought to examine the prevalence of gambling problems among a sample of casino patrons and examine alcohol and tobacco use, health status, and quality of life by gambling problem status. To these ends, 176 casino patrons were recruited by going to a Southern California casino and requesting that they complete an anonymous survey. Results indicated the following lifetime rates for at-risk, problem, and pathological gambling: 29.2, 10.7, and 29.8%. Differences were found with regards to gambling behavior, and results indicated higher rates of smoking among individuals with gambling problems, but not higher rates of alcohol use. Self-rated quality of life was lower among pathological gamblers relative to non-problem gamblers, but did not differ from at-risk or problem gamblers. Although subject to some limitations, our data support the notion of higher frequency of gambling problems among casino patrons and may suggest the need for increased interventions for gambling problems on-site at casinos.

Multi-frequency direct sampling method in inverse scattering problem

Science.gov (United States)

Kang, Sangwoo; Lambert, Marc; Park, Won-Kwang

2017-10-01

We consider the direct sampling method (DSM) for the two-dimensional inverse scattering problem. Although DSM is fast, stable, and effective, some phenomena remain unexplained by the existing results. We show that the imaging function of the direct sampling method can be expressed by a Bessel function of order zero. We also clarify the previously unexplained imaging phenomena and suggest multi-frequency DSM to overcome traditional DSM. Our method is evaluated in simulation studies using both single and multiple frequencies.

The two-sample problem with induced dependent censorship.

Science.gov (United States)

Huang, Y

1999-12-01

Induced dependent censorship is a general phenomenon in health service evaluation studies in which a measure such as quality-adjusted survival time or lifetime medical cost is of interest. We investigate the two-sample problem and propose two classes of nonparametric tests. Based on consistent estimation of the survival function for each sample, the two classes of test statistics examine the cumulative weighted difference in hazard functions and in survival functions. We derive a unified asymptotic null distribution theory and inference procedure. The tests are applied to trial V of the International Breast Cancer Study Group and show that long duration chemotherapy significantly improves time without symptoms of disease and toxicity of treatment as compared with the short duration treatment. Simulation studies demonstrate that the proposed tests, with a wide range of weight choices, perform well under moderate sample sizes.

On the Use of Importance Sampling in Particle Transport Problems

Energy Technology Data Exchange (ETDEWEB)

Eriksson, B

1965-06-15

The idea of importance sampling is applied to the problem of solving integral equations of Fredholm's type. Especially Bolzmann's neutron transport equation is taken into consideration. For the solution of the latter equation, an importance sampling technique is derived from some simple transformations at the original transport equation into a similar equation. Examples of transformations are given, which have been used with great success in practice.

On the Use of Importance Sampling in Particle Transport Problems

International Nuclear Information System (INIS)

Eriksson, B.

1965-06-01

The idea of importance sampling is applied to the problem of solving integral equations of Fredholm's type. Especially Bolzmann's neutron transport equation is taken into consideration. For the solution of the latter equation, an importance sampling technique is derived from some simple transformations at the original transport equation into a similar equation. Examples of transformations are given, which have been used with great success in practice

ON SAMPLING BASED METHODS FOR THE DUBINS TRAVELING SALESMAN PROBLEM WITH NEIGHBORHOODS

Directory of Open Access Journals (Sweden)

Petr Váňa

2015-12-01

Full Text Available In this paper, we address the problem of path planning to visit a set of regions by Dubins vehicle, which is also known as the Dubins Traveling Salesman Problem Neighborhoods (DTSPN. We propose a modification of the existing sampling-based approach to determine increasing number of samples per goal region and thus improve the solution quality if a more computational time is available. The proposed modification of the sampling-based algorithm has been compared with performance of existing approaches for the DTSPN and results of the quality of the found solutions and the required computational time are presented in the paper.

The relationship between gambling attitudes, involvement, and problems in adolescence: Examining the moderating role of coping strategies and parenting styles.

Science.gov (United States)

Dixon, Ramsay W; Youssef, George J; Hasking, Penelope; Yücel, Murat; Jackson, Alun C; Dowling, Nicki A

2016-07-01

Several factors are associated with an increased risk of adolescent problem gambling, including positive gambling attitudes, higher levels of gambling involvement, ineffective coping strategies and unhelpful parenting practices. It is less clear, however, how these factors interact or influence each other in the development of problem gambling behavior during adolescence. The aim of the current study was to simultaneously explore these predictors, with a particular focus on the extent to which coping skills and parenting styles may moderate the expected association between gambling involvement and gambling problems. Participants were 612 high school students. The data were analyzed using a zero-inflated Poisson (ZIP) regression model, controlling for gender. Although several variables predicted the number of symptoms associated with problem gambling, none of them predicted the probability of displaying any problem gambling. Gambling involvement fully mediated the relationship between positive gambling attitudes and gambling problem severity. There was a significant relationship between gambling involvement and problems at any level of problem focused coping, reference to others and inconsistent discipline. However, adaptive coping styles employed by adolescents and consistent disciplinary practices by parents were buffers of gambling problems at low levels of adolescent gambling involvement, but failed to protect adolescents when their gambling involvement was high. These findings indicate that research exploring the development of gambling problems is required and imply that coping and parenting interventions may have particular utility for adolescents who are at risk of development gambling problems but who are not gambling frequently. Copyright © 2016 Elsevier Ltd. All rights reserved.

The electron transport problem sampling by Monte Carlo individual collision technique

International Nuclear Information System (INIS)

Androsenko, P.A.; Belousov, V.I.

2005-01-01

The problem of electron transport is of most interest in all fields of the modern science. To solve this problem the Monte Carlo sampling has to be used. The electron transport is characterized by a large number of individual interactions. To simulate electron transport the 'condensed history' technique may be used where a large number of collisions are grouped into a single step to be sampled randomly. Another kind of Monte Carlo sampling is the individual collision technique. In comparison with condensed history technique researcher has the incontestable advantages. For example one does not need to give parameters altered by condensed history technique like upper limit for electron energy, resolution, number of sub-steps etc. Also the condensed history technique may lose some very important tracks of electrons because of its limited nature by step parameters of particle movement and due to weakness of algorithms for example energy indexing algorithm. There are no these disadvantages in the individual collision technique. This report presents some sampling algorithms of new version BRAND code where above mentioned technique is used. All information on electrons was taken from Endf-6 files. They are the important part of BRAND. These files have not been processed but directly taken from electron information source. Four kinds of interaction like the elastic interaction, the Bremsstrahlung, the atomic excitation and the atomic electro-ionization were considered. In this report some results of sampling are presented after comparison with analogs. For example the endovascular radiotherapy problem (P2) of QUADOS2002 was presented in comparison with another techniques that are usually used. (authors)

Privacy problems in the small sample selection

Directory of Open Access Journals (Sweden)

Loredana Cerbara

2013-05-01

Full Text Available The side of social research that uses small samples for the production of micro data, today finds some operating difficulties due to the privacy law. The privacy code is a really important and necessary law because it guarantees the Italian citizen’s rights, as already happens in other Countries of the world. However it does not seem appropriate to limit once more the possibilities of the data production of the national centres of research. That possibilities are already moreover compromised due to insufficient founds is a common problem becoming more and more frequent in the research field. It would be necessary, therefore, to include in the law the possibility to use telephonic lists to select samples useful for activities directly of interest and importance to the citizen, such as the collection of the data carried out on the basis of opinion polls by the centres of research of the Italian CNR and some universities.

A direct sampling method to an inverse medium scattering problem

KAUST Repository

Ito, Kazufumi; Jin, Bangti; Zou, Jun

2012-01-01

In this work we present a novel sampling method for time harmonic inverse medium scattering problems. It provides a simple tool to directly estimate the shape of the unknown scatterers (inhomogeneous media), and it is applicable even when

Gambling Type, Substance Abuse, Health and Psychosocial Correlates of Male and Female Problem Gamblers in a Nationally Representative French Sample.

Science.gov (United States)

Bonnaire, C; Kovess-Masfety, V; Guignard, R; Richard, J B; du Roscoät, E; Beck, F

2017-06-01

Many studies carried out on treatment-seeking problem gamblers (PG) have reported high levels of comorbid substance use disorders, and mental and physical health problems. Nevertheless, general population studies are still sparse, most of them have been carried out in the United States or Canada, and gender differences have not always been considered. Thus, the aim of this study was to describe the type of games, and psychological and physical correlates in male and female PG in a nationally representative French sample. The total sample studied involved 25,647 subjects aged 15-85 years, including 333 PG and 25,314 non-problem gamblers (NPG). Data were extracted from a large survey of a representative sample of the French general population. They were evaluated for sociodemographic variables, gambling behavior, type of gambling activity, substance use, psychological distress, body mass index, chronic disease, and lack of sleep. Overall, there were significant differences between PG and NPG in gender, age, education, employment and marital status, substance use disorders (alcohol, tobacco, cannabis, cocaine and heroin), psychological distress, obesity, lack of sleep and type of gambling activity. Although male and female PG had different profiles, the gambling type, especially strategic games, appeared as an important variable in the relationship between gender and problem gambling. This research underlines the importance of considering gender differences and gambling type in the study of gambling disorders. Identifying specific factors in the relationship between gender, gambling type and gambling problems may help improve clinical interventions and health promotion strategies.

Vibronic Boson Sampling: Generalized Gaussian Boson Sampling for Molecular Vibronic Spectra at Finite Temperature.

Science.gov (United States)

Huh, Joonsuk; Yung, Man-Hong

2017-08-07

Molecular vibroic spectroscopy, where the transitions involve non-trivial Bosonic correlation due to the Duschinsky Rotation, is strongly believed to be in a similar complexity class as Boson Sampling. At finite temperature, the problem is represented as a Boson Sampling experiment with correlated Gaussian input states. This molecular problem with temperature effect is intimately related to the various versions of Boson Sampling sharing the similar computational complexity. Here we provide a full description to this relation in the context of Gaussian Boson Sampling. We find a hierarchical structure, which illustrates the relationship among various Boson Sampling schemes. Specifically, we show that every instance of Gaussian Boson Sampling with an initial correlation can be simulated by an instance of Gaussian Boson Sampling without initial correlation, with only a polynomial overhead. Since every Gaussian state is associated with a thermal state, our result implies that every sampling problem in molecular vibronic transitions, at any temperature, can be simulated by Gaussian Boson Sampling associated with a product of vacuum modes. We refer such a generalized Gaussian Boson Sampling motivated by the molecular sampling problem as Vibronic Boson Sampling.

Marine sampling in Malaysia coastal area: the challenge, problems and solution

International Nuclear Information System (INIS)

Norfaizal Mohamed; Khairul Nizam Razali; Mohd Rafaie Mohd Murtadza; Muhammad Amin Abdul Ghani; Zaharudin Ahmad; Abdul Kadir Ishak

2005-01-01

Malaysia Marine Radioactivity Database Development Project is one of the five research contracts that was signed between MINT and AELB. Three marine sampling expeditions had been carried out using K.L. PAUS vessel owned by Malaysian Fisheries Institute, Chendering, Terengganu. The first marine sampling expedition was taken place at East Coast Peninsular Malaysia waters on August 2003, followed on February 2004 at West Coast Peninsular Malaysia waters, and lastly at Sarawak-Sabah waters on July 2004. Many challenges and problems were faced when collecting sediment, water, biota and plankton sample during this marine sampling. (Author)

The electron transport problem sampling by Monte Carlo individual collision technique

Energy Technology Data Exchange (ETDEWEB)

Androsenko, P.A.; Belousov, V.I. [Obninsk State Technical Univ. of Nuclear Power Engineering, Kaluga region (Russian Federation)

2005-07-01

The problem of electron transport is of most interest in all fields of the modern science. To solve this problem the Monte Carlo sampling has to be used. The electron transport is characterized by a large number of individual interactions. To simulate electron transport the 'condensed history' technique may be used where a large number of collisions are grouped into a single step to be sampled randomly. Another kind of Monte Carlo sampling is the individual collision technique. In comparison with condensed history technique researcher has the incontestable advantages. For example one does not need to give parameters altered by condensed history technique like upper limit for electron energy, resolution, number of sub-steps etc. Also the condensed history technique may lose some very important tracks of electrons because of its limited nature by step parameters of particle movement and due to weakness of algorithms for example energy indexing algorithm. There are no these disadvantages in the individual collision technique. This report presents some sampling algorithms of new version BRAND code where above mentioned technique is used. All information on electrons was taken from Endf-6 files. They are the important part of BRAND. These files have not been processed but directly taken from electron information source. Four kinds of interaction like the elastic interaction, the Bremsstrahlung, the atomic excitation and the atomic electro-ionization were considered. In this report some results of sampling are presented after comparison with analogs. For example the endovascular radiotherapy problem (P2) of QUADOS2002 was presented in comparison with another techniques that are usually used. (authors)

Psychiatric morbidity and people's experience of and response to social problems involving rights.

Science.gov (United States)

Balmer, Nigel J; Pleasence, Pascoe; Buck, Alexy

2010-11-01

Psychiatric morbidity has been shown to be associated with the increased reporting of a range of social problems involving legal rights ('rights problems'). Using a validated measure of psychiatric morbidity, this paper explores the relationship between psychiatric morbidity and rights problems and discusses the implications for the delivery of health and legal services. New representative national survey data from the English and Welsh Civil and Social Justice Survey (CSJS) surveyed 3040 adults in 2007 to explore the relationship between GHQ-12 scores and the self reported incidence of and behaviour surrounding, rights problems. It was found that the prevalence of rights problems increased with psychiatric morbidity, as did the experience of multiple problems. It was also found the likelihood of inaction in the face of problems increased with psychiatric morbidity, while the likelihood of choosing to resolve problems without help decreased. Where advice was obtained, psychiatric morbidity was associated with a greater tendency to obtain a combination of 'legal' and 'general' support, rather than 'legal' advice alone. The results suggest that integrated and 'outreach' services are of particular importance to the effective support of those facing mental illness. © 2010 Blackwell Publishing Ltd.

Parent-reported feeding and feeding problems in a sample of Dutch toddlers

NARCIS (Netherlands)

Moor, J.M.H. de; Didden, H.C.M.; Korzilius, H.P.L.M.

2007-01-01

Little is known about the feeding behaviors and problems with feeding in toddlers. In the present questionnaire study, data were collected on the feeding behaviors and feeding problems in a relatively large (n = 422) sample of Dutch healthy toddlers (i.e. 18-36 months old) who lived at home with

Families Affected by Huntington's Disease Report Difficulties in Communication, Emotional Involvement, and Problem Solving.

Science.gov (United States)

Jona, Celine M H; Labuschagne, Izelle; Mercieca, Emily-Clare; Fisher, Fiona; Gluyas, Cathy; Stout, Julie C; Andrews, Sophie C

2017-01-01

Family functioning in Huntington's disease (HD) is known from previous studies to be adversely affected. However, which aspects of family functioning are disrupted is unknown, limiting the empirical basis around which to create supportive interventions. The aim of the current study was to assess family functioning in HD families. We assessed family functioning in 61 participants (38 HD gene-expanded participants and 23 family members) using the McMaster Family Assessment Device (FAD; Epstein, Baldwin and Bishop, 1983), which provides scores for seven domains of functioning: Problem Solving; Communication; Affective Involvement; Affective Responsiveness; Behavior Control; Roles; and General Family Functioning. The most commonly reported disrupted domain for HD participants was Affective Involvement, which was reported by 39.5% of HD participants, followed closely by General Family Functioning (36.8%). For family members, the most commonly reported dysfunctional domains were Affective Involvement and Communication (both 52.2%). Furthermore, symptomatic HD participants reported more disruption to Problem Solving than pre-symptomatic HD participants. In terms of agreement between pre-symptomatic and symptomatic HD participants and their family members, all domains showed moderate to very good agreement. However, on average, family members rated Communication as more disrupted than their HD affected family member. These findings highlight the need to target areas of emotional engagement, communication skills and problem solving in family interventions in HD.

Experimental quantum annealing: case study involving the graph isomorphism problem.

Science.gov (United States)

Zick, Kenneth M; Shehab, Omar; French, Matthew

2015-06-08

Quantum annealing is a proposed combinatorial optimization technique meant to exploit quantum mechanical effects such as tunneling and entanglement. Real-world quantum annealing-based solvers require a combination of annealing and classical pre- and post-processing; at this early stage, little is known about how to partition and optimize the processing. This article presents an experimental case study of quantum annealing and some of the factors involved in real-world solvers, using a 504-qubit D-Wave Two machine and the graph isomorphism problem. To illustrate the role of classical pre-processing, a compact Hamiltonian is presented that enables a reduced Ising model for each problem instance. On random N-vertex graphs, the median number of variables is reduced from N(2) to fewer than N log2 N and solvable graph sizes increase from N = 5 to N = 13. Additionally, error correction via classical post-processing majority voting is evaluated. While the solution times are not competitive with classical approaches to graph isomorphism, the enhanced solver ultimately classified correctly every problem that was mapped to the processor and demonstrated clear advantages over the baseline approach. The results shed some light on the nature of real-world quantum annealing and the associated hybrid classical-quantum solvers.

Toward a mathematical theory of environmental monitoring: the infrequent sampling problem

International Nuclear Information System (INIS)

Pimentel, K.D.

1975-06-01

Optimal monitoring of pollutants in diffusive environmental media was studied in the contexts of the subproblems of the optimal design and management of environmental monitors for bounds on maximum allowable errors in the estimate of the monitor state or output variables. Concise problem statements were made. Continuous-time finite-dimensional normal mode models for distributed stochastic diffusive pollutant transport were developed. The resultant set of state equations was discretized in time for implementation in the Kalman Filter in the problem of optimal state estimation. The main results of this thesis concern the special class of optimal monitoring problem called the infrequent sampling problem. Extensions to systems including pollutant scavenging and systems with emission or radiation boundary conditions were made. (U.S.)

NASTRAN thermal analyzer: Theory and application including a guide to modeling engineering problems, volume 2. [sample problem library guide

Science.gov (United States)

Jackson, C. E., Jr.

1977-01-01

A sample problem library containing 20 problems covering most facets of Nastran Thermal Analyzer modeling is presented. Areas discussed include radiative interchange, arbitrary nonlinear loads, transient temperature and steady-state structural plots, temperature-dependent conductivities, simulated multi-layer insulation, and constraint techniques. The use of the major control options and important DMAP alters is demonstrated.

Novel Numerical Methods for Optimal Control Problems Involving Fractional-Order Differential Equations

Science.gov (United States)

2018-03-14

UNIVERSITY OF TECHNOLOGY Final Report 03/14/2018 DISTRIBUTION A: Distribution approved for public release. AF Office Of Scientific Research (AFOSR...optimal control problems involving fractional-order differential equations Wang, Song Curtin University of Technology Kent Street, Bentley WA6102...Article history : Received 3 October 2016 Accepted 26 March 2017 Available online 29 April 2017 Keywords: Hamilton–Jacobi–Bellman equation Financial

Sample problem calculations related to two-phase flow transients in a PWR relief-piping network

International Nuclear Information System (INIS)

Shin, Y.W.; Wiedermann, A.H.

1981-03-01

Two sample problems related with the fast transients of water/steam flow in the relief line of a PWR pressurizer were calculated with a network-flow analysis computer code STAC (System Transient-Flow Analysis Code). The sample problems were supplied by EPRI and are designed to test computer codes or computational methods to determine whether they have the basic capability to handle the important flow features present in a typical relief line of a PWR pressurizer. It was found necessary to implement into the STAC code a number of additional boundary conditions in order to calculate the sample problems. This includes the dynamics of the fluid interface that is treated as a moving boundary. This report describes the methodologies adopted for handling the newly implemented boundary conditions and the computational results of the two sample problems. In order to demonstrate the accuracies achieved in the STAC code results, analytical solutions are also obtained and used as a basis for comparison

Problems pilots face involving wind shear

Science.gov (United States)

Melvin, W. W.

1977-01-01

Educating pilots and the aviation industry about wind shears presents a major problem associated with this meteorological phenomenon. The pilot's second most pressing problem is the need for a language to discuss wind shear encounters with other pilots so that the reaction of the aircraft to the wind shear encounter can be accurately described. Another problem is the flight director which gives a centered pitch command for a given angular displacement from the glide slope. It was suggested that they should instead be called flight path command and should not center unless the aircraft is actually correcting to the flight path.

Pain, Bullying Involvement, and Mental Health Problems Among Children and Adolescents With ADHD in Taiwan.

Science.gov (United States)

Yeh, Yi-Chun; Huang, Mei-Feng; Wu, Yu-Yu; Hu, Huei-Fan; Yen, Cheng-Fang

2017-08-01

The aim of this study was to examine the relationships of pain and pain-induced functional impairment with bullying involvement, as well as the relationships between pain and mental health problems among 474 children and adolescents with ADHD. The levels of pain, pain-induced functional impairment, involvement in bullying, depression, anxiety, ADHD symptoms, and sleep quality were assessed. Both victims of verbal and relational bullying and victims of physical bullying were more likely to have pain and pain-induced functional impairment than nonvictims. The perpetrators of verbal and relational bullying were more likely to have pain than the nonperpetrators. Participants with pain and pain-induced functional impairment experienced more severe depression and anxiety and worse sleep quality than did those without pain or pain-induced functional impairment. Clinical and educational professionals should consider the possibility of involvement in bullying and comorbid depression, anxiety, and poor sleep quality among ADHD children and adolescents with pain problems.

Recent bibliography on analytical and sampling problems of a PWR primary coolant

International Nuclear Information System (INIS)

Illy, H.

1980-07-01

An extensive bibliography on the problems of analysis and sampling of the primary cooling water of PWRs is presented. The aim was to collect the analytical methods for dissolved gases. The sampling and preparation are also taken into account. last 8-10 years is included. The bibliography is arranged into alphabetical order by topics. The most important topics are as follows: boric acid, gas analysis, hydrogen isotopes, iodine, noble gases, radiation monitoring, sampling and preparation, water chemistry. (R.J.)

A Comparative Study of Involvement and Motivation among Casino Gamblers.

Science.gov (United States)

Lee, Choong-Ki; Lee, Bongkoo; Bernhard, Bo Jason; Lee, Tae Kyung

2009-09-01

The purpose of this paper is to investigate three different types of gamblers (which we label "non-problem", "some problem", and "probable pathological gamblers") to determine differences in involvement and motivation, as well as differences in demographic and behavioral variables. The analysis takes advantage of a unique opportunity to sample on-site at a major casino in South Korea, and the resulting purposive sample yielded 180 completed questionnaires in each of the three groups, for a total number of 540. Factor analysis, analysis of variance (ANOVA) and Duncan tests, and Chi-square tests are employed to analyze the data collected from the survey. Findings from ANOVA tests indicate that involvement factors of importance/self-expression, pleasure/interest, and centrality derived from the factor analysis were significantly different among these three types of gamblers. The "probable pathological" and "some problem" gamblers were found to have similar degrees of involvement, and higher degrees of involvement than the non-problem gamblers. The tests also reveal that motivational factors of escape, socialization, winning, and exploring scenery were significantly different among these three types of gamblers. When looking at motivations to visit the casino, "probable pathological" gamblers were more likely to seek winning, the "some problem" group appeared to be more likely to seek escape, and the "non-problem" gamblers indicate that their motivations to visit centered around explorations of scenery and culture in the surrounding casino area. The tools for exploring motivations and involvements of gambling provide valuable and discerning information about the entire spectrum of gamblers.

A Comparative Study of Involvement and Motivation among Casino Gamblers

Science.gov (United States)

Lee, Choong-Ki; Lee, BongKoo; Bernhard, Bo Jason

2009-01-01

Objective The purpose of this paper is to investigate three different types of gamblers (which we label "non-problem", "some problem", and "probable pathological gamblers") to determine differences in involvement and motivation, as well as differences in demographic and behavioral variables. Methods The analysis takes advantage of a unique opportunity to sample on-site at a major casino in South Korea, and the resulting purposive sample yielded 180 completed questionnaires in each of the three groups, for a total number of 540. Factor analysis, analysis of variance (ANOVA) and Duncan tests, and Chi-square tests are employed to analyze the data collected from the survey. Results Findings from ANOVA tests indicate that involvement factors of importance/self-expression, pleasure/interest, and centrality derived from the factor analysis were significantly different among these three types of gamblers. The "probable pathological" and "some problem" gamblers were found to have similar degrees of involvement, and higher degrees of involvement than the non-problem gamblers. The tests also reveal that motivational factors of escape, socialization, winning, and exploring scenery were significantly different among these three types of gamblers. When looking at motivations to visit the casino, "probable pathological" gamblers were more likely to seek winning, the "some problem" group appeared to be more likely to seek escape, and the "non-problem" gamblers indicate that their motivations to visit centered around explorations of scenery and culture in the surrounding casino area. Conclusion The tools for exploring motivations and involvements of gambling provide valuable and discerning information about the entire spectrum of gamblers. PMID:20046388

Virtual sampling in variational processing of Monte Carlo simulation in a deep neutron penetration problem

International Nuclear Information System (INIS)

Allagi, Mabruk O.; Lewins, Jeffery D.

1999-01-01

In a further study of virtually processed Monte Carlo estimates in neutron transport, a shielding problem has been studied. The use of virtual sampling to estimate the importance function at a certain point in the phase space depends on the presence of neutrons from the real source at that point. But in deep penetration problems, not many neutrons will reach regions far away from the source. In order to overcome this problem, two suggestions are considered: (1) virtual sampling is used as far as the real neutrons can reach, then fictitious sampling is introduced for the remaining regions, distributed in all the regions, or (2) only one fictitious source is placed where the real neutrons almost terminate and then virtual sampling is used in the same way as for the real source. Variational processing is again found to improve the Monte Carlo estimates, being best when using one fictitious source in the far regions with virtual sampling (option 2). When fictitious sources are used to estimate the importances in regions far away from the source, some optimization has to be performed for the proportion of fictitious to real sources, weighted against accuracy and computational costs. It has been found in this study that the optimum number of cells to be treated by fictitious sampling is problem dependent, but as a rule of thumb, fictitious sampling should be employed in regions where the number of neutrons from the real source fall below a specified limit for good statistics

The physico-chemical problems involved in condenser cooling, circuit sealing and stain

International Nuclear Information System (INIS)

Ropars, Jean.

1975-01-01

Today thermal production of electric energy requiers the use of steam turbines and then needs cold sources (condensers), the latter being obtained by means of a water circulation. Considerable amounts of water are involved. For instance, as for a 900MW power plant of the PWR type, a 12 deg C heating needs 40m 3 /s of cooling water. The needs in water introduce a limitation in the possible site selection for power plant settling (seaside or river with an important steady flow). The important amounts of heat involved create environmental problems. Means for limiting the heat amount released consist in using atmospheric cooling systems. A further constraint relating to scaling is added to the usual corrosion and stain problems when operating the devices. Changes in the carbon dioxide equilibrium and concentration due to the passage through the air cooling systems causes such scaling formation. The evolution of the physico-chemical parameters of the cooling water is described with the risks resulting for the circuits. Means to be developed for preventing scaling, stain and corrosion are presented. The solutions kept by E.D.F. for the exploitation of cooling circuits are indicated. The procedure developed must avoid any chemical pollution of water wastes [fr

Families Affected by Huntington’s Disease Report Difficulties in Communication, Emotional Involvement, and Problem Solving

Science.gov (United States)

Jona, Celine M.H.; Labuschagne, Izelle; Mercieca, Emily-Clare; Fisher, Fiona; Gluyas, Cathy; Stout, Julie C.; Andrews, Sophie C.

2017-01-01

Background: Family functioning in Huntington’s disease (HD) is known from previous studies to be adversely affected. However, which aspects of family functioning are disrupted is unknown, limiting the empirical basis around which to create supportive interventions. Objective: The aim of the current study was to assess family functioning in HD families. Methods: We assessed family functioning in 61 participants (38 HD gene-expanded participants and 23 family members) using the McMaster Family Assessment Device (FAD; Epstein, Baldwin and Bishop, 1983), which provides scores for seven domains of functioning: Problem Solving; Communication; Affective Involvement; Affective Responsiveness; Behavior Control; Roles; and General Family Functioning. Results: The most commonly reported disrupted domain for HD participants was Affective Involvement, which was reported by 39.5% of HD participants, followed closely by General Family Functioning (36.8%). For family members, the most commonly reported dysfunctional domains were Affective Involvement and Communication (both 52.2%). Furthermore, symptomatic HD participants reported more disruption to Problem Solving than pre-symptomatic HD participants. In terms of agreement between pre-symptomatic and symptomatic HD participants and their family members, all domains showed moderate to very good agreement. However, on average, family members rated Communication as more disrupted than their HD affected family member. Conclusion: These findings highlight the need to target areas of emotional engagement, communication skills and problem solving in family interventions in HD. PMID:28968240

Model correction factor method for reliability problems involving integrals of non-Gaussian random fields

DEFF Research Database (Denmark)

Franchin, P.; Ditlevsen, Ove Dalager; Kiureghian, Armen Der

2002-01-01

The model correction factor method (MCFM) is used in conjunction with the first-order reliability method (FORM) to solve structural reliability problems involving integrals of non-Gaussian random fields. The approach replaces the limit-state function with an idealized one, in which the integrals ...

Problem Gambling in a Sample of Older Adult Casino Gamblers.

Science.gov (United States)

van der Maas, Mark; Mann, Robert E; McCready, John; Matheson, Flora I; Turner, Nigel E; Hamilton, Hayley A; Schrans, Tracy; Ialomiteanu, Anca

2017-01-01

As older adults continue to make up a greater proportion of the Canadian population, it becomes more important to understand the implications that their leisure activities have for their physical and mental health. Gambling, in particular, is a form of leisure that is becoming more widely available and has important implications for the mental health and financial well-being of older adults. This study examines a large sample (2103) of casino-going Ontarian adults over the age of 55 and identifies those features of their gambling participation that are associated with problem gambling. Logistic regression analysis is used to analyze the data. Focusing on types of gambling participated in and motivations for visiting the casino, this study finds that several forms of gambling and motivations to gamble are associated with greater risk of problem gambling. It also finds that some motivations are associated with lower risk of problem gambling. The findings of this study have implications related to gambling availability within an aging population.

Exploring the Connection Between Sampling Problems in Bayesian Inference and Statistical Mechanics

Science.gov (United States)

Pohorille, Andrew

2006-01-01

The Bayesian and statistical mechanical communities often share the same objective in their work - estimating and integrating probability distribution functions (pdfs) describing stochastic systems, models or processes. Frequently, these pdfs are complex functions of random variables exhibiting multiple, well separated local minima. Conventional strategies for sampling such pdfs are inefficient, sometimes leading to an apparent non-ergodic behavior. Several recently developed techniques for handling this problem have been successfully applied in statistical mechanics. In the multicanonical and Wang-Landau Monte Carlo (MC) methods, the correct pdfs are recovered from uniform sampling of the parameter space by iteratively establishing proper weighting factors connecting these distributions. Trivial generalizations allow for sampling from any chosen pdf. The closely related transition matrix method relies on estimating transition probabilities between different states. All these methods proved to generate estimates of pdfs with high statistical accuracy. In another MC technique, parallel tempering, several random walks, each corresponding to a different value of a parameter (e.g. "temperature"), are generated and occasionally exchanged using the Metropolis criterion. This method can be considered as a statistically correct version of simulated annealing. An alternative approach is to represent the set of independent variables as a Hamiltonian system. Considerab!e progress has been made in understanding how to ensure that the system obeys the equipartition theorem or, equivalently, that coupling between the variables is correctly described. Then a host of techniques developed for dynamical systems can be used. Among them, probably the most powerful is the Adaptive Biasing Force method, in which thermodynamic integration and biased sampling are combined to yield very efficient estimates of pdfs. The third class of methods deals with transitions between states described

Clustering problems for geochemical data

International Nuclear Information System (INIS)

Kane, V.E.; Larson, N.M.

1977-01-01

The Union Carbide Corporation, Nuclear Division, Uranium Resource Evaluation Project uses a two-stage sampling program to identify potential uranium districts. Cluster analysis techniques are used in locating high density sampling areas as well as in identifying potential uranium districts. Problems are considered involving the analysis of multivariate censored data, laboratory measurement error, and data standardization

Applications of Asymptotic Sampling on High Dimensional Structural Dynamic Problems

DEFF Research Database (Denmark)

Sichani, Mahdi Teimouri; Nielsen, Søren R.K.; Bucher, Christian

2011-01-01

The paper represents application of the asymptotic sampling on various structural models subjected to random excitations. A detailed study on the effect of different distributions of the so-called support points is performed. This study shows that the distribution of the support points has consid...... dimensional reliability problems in structural dynamics.......The paper represents application of the asymptotic sampling on various structural models subjected to random excitations. A detailed study on the effect of different distributions of the so-called support points is performed. This study shows that the distribution of the support points has...... is minimized. Next, the method is applied on different cases of linear and nonlinear systems with a large number of random variables representing the dynamic excitation. The results show that asymptotic sampling is capable of providing good approximations of low failure probability events for very high...

Improving Creative Problem-Solving in a Sample of Third Culture Kids

Science.gov (United States)

Lee, Young Ju; Bain, Sherry K.; McCallum, R. Steve

2007-01-01

We investigated the effects of divergent thinking training (with explicit instruction) on problem-solving tasks in a sample of Third Culture Kids (Useem and Downie, 1976). We were specifically interested in whether the children's originality and fluency in responding increased following instruction, not only on classroom-based worksheets and the…

Symptoms and problems in a nationally representative sample of advanced cancer patients

DEFF Research Database (Denmark)

Johnsen, Anna Thit; Petersen, Morten Aagaard; Pedersen, Lise

2009-01-01

Little is known about the need for palliative care among advanced cancer patients who are not in specialist palliative care. The purpose was to identify prevalence and predictors of symptoms and problems in a nationally representative sample of Danish advanced cancer patients. Patients with cancer...... or not were associated with several symptoms and problems. This is probably the first nationally representative study of its kind. It shows that advanced cancer patients in Denmark have symptoms and problems that deserve attention and that some patient groups are especially at risk....... predictors. In total, 977 (60%) patients participated. The most frequent symptoms/problems were fatigue (57%; severe 22%) followed by reduced role function, insomnia and pain. Age, cancer stage, primary tumour, type of department, marital status and whether the patient had recently been hospitalized...

Inverse problems with non-trivial priors: efficient solution through sequential Gibbs sampling

DEFF Research Database (Denmark)

Hansen, Thomas Mejer; Cordua, Knud Skou; Mosegaard, Klaus

2012-01-01

Markov chain Monte Carlo methods such as the Gibbs sampler and the Metropolis algorithm can be used to sample solutions to non-linear inverse problems. In principle, these methods allow incorporation of prior information of arbitrary complexity. If an analytical closed form description of the prior...... is available, which is the case when the prior can be described by a multidimensional Gaussian distribution, such prior information can easily be considered. In reality, prior information is often more complex than can be described by the Gaussian model, and no closed form expression of the prior can be given....... We propose an algorithm, called sequential Gibbs sampling, allowing the Metropolis algorithm to efficiently incorporate complex priors into the solution of an inverse problem, also for the case where no closed form description of the prior exists. First, we lay out the theoretical background...

When addiction symptoms and life problems diverge: a latent class analysis of problematic gaming in a representative multinational sample of European adolescents.

Science.gov (United States)

Colder Carras, Michelle; Kardefelt-Winther, Daniel

2018-04-01

The proposed diagnosis of Internet gaming disorder (IGD) in DSM-5 has been criticized for "borrowing" criteria related to substance addiction, as this might result in misclassifying highly involved gamers as having a disorder. In this paper, we took a person-centered statistical approach to group adolescent gamers by levels of addiction-related symptoms and gaming-related problems, compared these groups to traditional scale scores for IGD, and checked how groups were related to psychosocial well-being using a preregistered analysis plan. We performed latent class analysis and regression with items from IGD and psychosocial well-being scales in a representative sample of 7865 adolescent European gamers. Symptoms and problems matched in only two groups: an IGD class (2.2%) having a high level of symptoms and problems and a Normative class (63.5%) having low levels of symptoms and problems. We also identified two classes comprising 30.9% of our sample that would be misclassified based on their report of gaming-related problems: an Engaged class (7.3%) that seemed to correspond to the engaged gamers described in previous literature, and a Concerned class (23.6%) reporting few symptoms but moderate to high levels of problems. Our findings suggest that a reformulation of IGD is needed. Treating Engaged gamers as having IGD when their poor well-being might not be gaming related may delay appropriate treatment, while Concerned gamers may need help to reduce gaming but would not be identified as such. Additional work to describe the phenomenology of these two groups would help refine diagnosis, prevention and treatment for IGD.

Adolescents' viewing of suicide-related web-content and psychological problems: differentiating the roles of cyberbullying involvement

OpenAIRE

Görzig, Anke

2016-01-01

Possible links of cyberbullying with suicide and psychological problems have recently received considerable attention. Suicide-related behaviours have also been linked with viewing of associated web-content. Studies on traditional bullying indicate that the roles of bullying involvement (bullies, victims and bully-victims) matter in terms of associations with specific suicide-related behaviours and psychological problems. Yet, related research in the area of cyberbullying is lacking. The curr...

Strategies, Not Solutions: Involving Students in Problem Solving.

Science.gov (United States)

Von Kuster, Lee N.

1984-01-01

Defines problem solving, discusses the use of problems developed by students that are relevant to their own lives, presents examples of practical mathematics problems that deal with local situations, discusses fringe benefits of this type of problem solving, and addresses teachers' concern that this method consumes too much time. (MBR)

Advanced Curation: Solving Current and Future Sample Return Problems

Science.gov (United States)

Fries, M.; Calaway, M.; Evans, C.; McCubbin, F.

2015-01-01

Advanced Curation is a wide-ranging and comprehensive research and development effort at NASA Johnson Space Center that identifies and remediates sample related issues. For current collections, Advanced Curation investigates new cleaning, verification, and analytical techniques to assess their suitability for improving curation processes. Specific needs are also assessed for future sample return missions. For each need, a written plan is drawn up to achieve the requirement. The plan draws while upon current Curation practices, input from Curators, the analytical expertise of the Astromaterials Research and Exploration Science (ARES) team, and suitable standards maintained by ISO, IEST, NIST and other institutions. Additionally, new technologies are adopted on the bases of need and availability. Implementation plans are tested using customized trial programs with statistically robust courses of measurement, and are iterated if necessary until an implementable protocol is established. Upcoming and potential NASA missions such as OSIRIS-REx, the Asteroid Retrieval Mission (ARM), sample return missions in the New Frontiers program, and Mars sample return (MSR) all feature new difficulties and specialized sample handling requirements. The Mars 2020 mission in particular poses a suite of challenges since the mission will cache martian samples for possible return to Earth. In anticipation of future MSR, the following problems are among those under investigation: What is the most efficient means to achieve the less than 1.0 ng/sq cm total organic carbon (TOC) cleanliness required for all sample handling hardware? How do we maintain and verify cleanliness at this level? The Mars 2020 Organic Contamination Panel (OCP) predicts that organic carbon, if present, will be present at the "one to tens" of ppb level in martian near-surface samples. The same samples will likely contain wt% perchlorate salts, or approximately 1,000,000x as much perchlorate oxidizer as organic carbon

The effects of recurrent physical abuse on the co-development of behavior problems and posttraumatic stress symptoms among child welfare-involved youth.

Science.gov (United States)

Yoon, Susan; Barnhart, Sheila; Cage, Jamie

2018-04-27

The primary aim of the current study was to examine the longitudinal effects of ongoing physical abuse on the co-development of externalizing behavior problems and posttraumatic stress (PTS) symptoms among child welfare-involved adolescents. Using three waves of data from the National Survey of Child and Adolescent Well-Being, we performed unconditional and conditional parallel process latent growth curve modeling in a structural equation modeling framework. The study sample included 491 adolescents who were between 11 and 13 years of age at baseline. Higher levels of initial PTS symptoms were associated with higher levels of externalizing behavior problems, but the rate of change in PTS symptoms were not significantly associated with the rate of change in externalizing behavior problems over time. Although physical abuse was concurrently associated with both externalizing behavior problems and PTS symptoms at all assessment points, there were no lagged effects. Additionally, we found that physical abuse indirectly affects subsequent development of externalizing behavior problems and PTS symptoms through ongoing physical abuse. Findings highlight the comorbidity of externalizing behaviors and PTS symptoms among early adolescents in the child welfare system, underlining the importance of screening for and addressing these problems simultaneously. Findings also point to the need for continued assessment of and protection from ongoing physical abuse during adolescence. Copyright © 2018 Elsevier Ltd. All rights reserved.

The association between childhood maltreatment and gambling problems in a community sample of adult men and women.

Science.gov (United States)

Hodgins, David C; Schopflocher, Don P; el-Guebaly, Nady; Casey, David M; Smith, Garry J; Williams, Robert J; Wood, Robert T

2010-09-01

The association between childhood maltreatment and gambling problems was examined in a community sample of men and women (N = 1,372). As hypothesized, individuals with gambling problems reported greater childhood maltreatment than individuals without gambling problems. Childhood maltreatment predicted severity of gambling problems and frequency of gambling even when other individual and social factors were controlled including symptoms of alcohol and other drug use disorders, family environment, psychological distress, and symptoms of antisocial disorder. In contrast to findings in treatment-seeking samples, women with gambling problems did not report greater maltreatment than men with gambling problems. These results underscore the need for both increased prevention of childhood maltreatment and increased sensitivity towards trauma issues in gambling treatment programs for men and women.

The problem of sampling families rather than populations: Relatedness among individuals in samples of juvenile brown trout Salmo trutta L

DEFF Research Database (Denmark)

Hansen, Michael Møller; Eg Nielsen, Einar; Mensberg, Karen-Lise Dons

1997-01-01

In species exhibiting a nonrandom distribution of closely related individuals, sampling of a few families may lead to biased estimates of allele frequencies in populations. This problem was studied in two brown trout populations, based on analysis of mtDNA and microsatellites. In both samples mt......DNA haplotype frequencies differed significantly between age classes, and in one sample 17 out of 18 individuals less than 1 year of age shared one particular mtDNA haplotype. Estimates of relatedness showed that these individuals most likely represented only three full-sib families. Older trout exhibiting...

Spectral methods for a nonlinear initial value problem involving pseudo differential operators

International Nuclear Information System (INIS)

Pasciak, J.E.

1982-01-01

Spectral methods (Fourier methods) for approximating the solution of a nonlinear initial value problem involving pseudo differential operators are defined and analyzed. A semidiscrete approximation to the nonlinear equation based on an L 2 projection is described. The semidiscrete L 2 approximation is shown to be a priori stable and convergent under sufficient decay and smoothness assumptions on the initial data. It is shown that the semidiscrete method converges with infinite order, that is, higher order decay and smoothness assumptions imply higher order error bounds. Spectral schemes based on spacial collocation are also discussed

Involving parents in cognitive-behavioral therapy for child anxiety problems: a case study

OpenAIRE

Siddaway, Andy P; Wood, Alex M; Cartwright-Hatton, Sam

2014-01-01

This case study examines how parents can be incorporated into all aspects of cognitive-behavioral therapy (CBT) for child anxiety problems. This is an important issue, because although there are strong theoretical and empirical reasons for incorporating parents into treatment, evidence from randomized controlled trials has so far been inconclusive about whether outcomes are improved by involving parents. This case study describes the clinical benefits of a balanced focus on parent and child f...

Greater involvement and diversity of Internet gambling as a risk factor for problem gambling

Science.gov (United States)

Russell, Alex; Blaszczynski, Alex; Hing, Nerilee

2015-01-01

Background: Concerns that Internet gambling has elevated the prevalence of problem gambling have not been substantiated; however, evidence suggests a subgroup of Internet gamblers do experience higher rates of gambling harms. Greater overall involvement in gambling appears to be predictive of harms. The purpose of this study was to examine differences between Internet gamblers with a single or multiple online gambling accounts, including their gambling behaviours, factors influencing their online gambling and risk of experiencing gambling problems. Methods: Internet gamblers (3178) responding to an online survey that assessed their gambling behaviour, and use of single or multiple online gambling accounts. Results: Results revealed that multiple account holders were more involved gamblers, gambling on more activities and more frequently, and had higher rates of gambling problems than single account holders. Multiple account holders selected gambling sites based on price, betting options, payout rates and game experience, whereas single account holders prioritized legality and consumer protection features. Conclusion: Results suggest two different types of Internet gamblers: one motivated to move between sites to optimize preferred experiences with a tendency to gamble in a more volatile manner; and a smaller, but more stable group less influenced by promotions and experiences, and seeking a reputable and safe gambling experience. As the majority of Internet gamblers use multiple accounts, more universal responsible gambling strategies are needed to assist gamblers to track and control their expenditure to reduce risks of harm. PMID:25745873

Unit Stratified Sampling as a Tool for Approximation of Stochastic Optimization Problems

Czech Academy of Sciences Publication Activity Database

Šmíd, Martin

2012-01-01

Roč. 19, č. 30 (2012), s. 153-169 ISSN 1212-074X R&D Projects: GA ČR GAP402/11/0150; GA ČR GAP402/10/0956; GA ČR GA402/09/0965 Institutional research plan: CEZ:AV0Z10750506 Institutional support: RVO:67985556 Keywords : Stochastic programming * approximation * stratified sampling Subject RIV: BB - Applied Statistics, Operational Research http://library.utia.cas.cz/separaty/2013/E/smid-unit stratified sampling as a tool for approximation of stochastic optimization problems.pdf

Robustness to non-normality of various tests for the one-sample location problem

Directory of Open Access Journals (Sweden)

Michelle K. McDougall

2004-01-01

Full Text Available This paper studies the effect of the normal distribution assumption on the power and size of the sign test, Wilcoxon's signed rank test and the t-test when used in one-sample location problems. Power functions for these tests under various skewness and kurtosis conditions are produced for several sample sizes from simulated data using the g-and-k distribution of MacGillivray and Cannon [5].

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.

Problems involving salaried managers in Russia

OpenAIRE

Nelyubina Maria Alexandrovna

2011-01-01

The article is devoted relationships between owners of the company and top-managers. Problems of top-management motivation, shareholders` control, liability of infringement of the rights and interests of shareholders are investigated.

Self-recognition of mental health problems in a rural Australian sample.

Science.gov (United States)

Handley, Tonelle E; Lewin, Terry J; Perkins, David; Kelly, Brian

2018-04-19

Although mental health literacy has increased in recent years, mental illness is often under-recognised. There has been little research conducted on mental illness in rural areas; however, this can be most prominent in rural areas due to factors such as greater stigma and stoicism. The aim of this study is to create a profile of those who are most and least likely to self-identify mental health problems among rural residents with moderate- to-high psychological distress. Secondary analysis of a longitudinal postal survey. Rural and remote New South Wales, Australia. Four-hundred-and-seventy-two community residents. Participants completed the K10 Psychological Distress Scale, as well as the question 'In the past 12 months have you experienced any mental health problems?' The characteristics of those who reported moderate/high distress scores were explored by comparing those who did and did not experience mental health problems recently. Of the 472 participants, 319 (68%) with moderate/high distress reported a mental health problem. Reporting a mental health problem was higher among those with recent adverse life events or who perceived more stress from life events while lower among those who attributed their symptoms to a physical cause. Among a rural sample with moderate/high distress, one-third did not report a mental health problem. Results suggest a threshold effect, whereby mental health problems are more likely to be acknowledged in the context of additional life events. Ongoing public health campaigns are necessary to ensure that symptoms of mental illness are recognised in the multiple forms that they take. © 2018 National Rural Health Alliance Ltd.

Problem drinking among at-risk college students: The examination of Greek involvement, freshman status, and history of mental health problems.

Science.gov (United States)

Martinez, Haley S; Klanecky, Alicia K; McChargue, Dennis E

2018-02-06

Scarce research has examined the combined effect of mental health difficulties and demographic risk factors such as freshman status and Greek affiliation in understanding college problem drinking. The current study is interested in looking at the interaction among freshman status, Greek affiliation, and mental health difficulties. Undergraduate students (N = 413) from a private and public Midwestern university completed a large online survey battery between January 2009 and April 2013. Data from both schools were aggregated for the analyses. After accounting for gender, age, and school type, the three-way interaction indicated that the highest drinking levels were reported in freshman students who reported a history of mental health problems although were not involved in Greek life. Findings are discussed in the context of perceived social norms, as well as alcohol-related screenings and intervention opportunities on college campuses.

Attention deficit hyperactivity disorder, other mental health problems, substance use, and driving: examination of a population-based, representative canadian sample.

Science.gov (United States)

Vingilis, Evelyn; Mann, Robert E; Erickson, Patricia; Toplak, Maggie; Kolla, Nathan J; Seeley, Jane; Jain, Umesh

2014-01-01

The purpose of this study is to examine the relationships among self-reported screening measures of attention deficit hyperactivity disorder (ADHD), other psychiatric problems, and driving-related outcomes in a provincially representative sample of adults 18 years and older living in the province of Ontario, Canada. The study examined the results of the Centre for Addictions and Mental Health (CAMH) Ontario Monitor, an ongoing repeated cross-sectional telephone survey of Ontario adults over a 2-year period. Measures included ADHD measures (Adult ADHD Self-Report Scale-V1.1 [ASRS-V1.1], previous ADHD diagnosis, ADHD medication use); psychiatric distress measures (General Health Questionnaire [GHQ12], use of pain, anxiety, and depression medication); antisocial behavior measure (The Antisocial Personality Disorder Scale from the Mini-International Neuropsychiatric Interview [APD]); substance use and abuse measures (alcohol, cannabis, and cocaine), Alcohol Use Disorders Identification Test (AUDIT), Alcohol, Smoking and Substance Involvement Screening Test (ASSIST), driving-related outcomes (driving after drinking, driving after cannabis use, street racing, collisions in past year), and sociodemographics (gender, age, vehicle-kilometers traveled). A total of 4,014 Ontario residents were sampled, of which 3,485 reported having a valid driver's license. Overall, 3.22% screened positive for ADHD symptoms on the ASRS-V1.1 screening tool. A greater percentage of those who screened positive were younger, reported previous ADHD diagnosis and medication use, distress, antisocial behavior, anti-anxiety and antidepressant medication use, substance use, and social problems compared to those who screened negative. However, there were no statistically significant differences between those who screened positive or negative for ADHD symptoms on self-reported driving after having 2 or more drinks in the previous hour; within an hour of using cannabis, marijuana, or hash; or in a

Problems involving salaried managers in Russia

Directory of Open Access Journals (Sweden)

Nelyubina Maria Alexandrovna

2011-10-01

Full Text Available The article is devoted relationships between owners of the company and top-managers. Problems of top-management motivation, shareholders` control, liability of infringement of the rights and interests of shareholders are investigated.

Greater involvement and diversity of Internet gambling as a risk factor for problem gambling.

Science.gov (United States)

Gainsbury, Sally M; Russell, Alex; Blaszczynski, Alex; Hing, Nerilee

2015-08-01

Concerns that Internet gambling has elevated the prevalence of problem gambling have not been substantiated; however, evidence suggests a subgroup of Internet gamblers do experience higher rates of gambling harms. Greater overall involvement in gambling appears to be predictive of harms. The purpose of this study was to examine differences between Internet gamblers with a single or multiple online gambling accounts, including their gambling behaviours, factors influencing their online gambling and risk of experiencing gambling problems. Internet gamblers (3178) responding to an online survey that assessed their gambling behaviour, and use of single or multiple online gambling accounts. Results revealed that multiple account holders were more involved gamblers, gambling on more activities and more frequently, and had higher rates of gambling problems than single account holders. Multiple account holders selected gambling sites based on price, betting options, payout rates and game experience, whereas single account holders prioritized legality and consumer protection features. Results suggest two different types of Internet gamblers: one motivated to move between sites to optimize preferred experiences with a tendency to gamble in a more volatile manner; and a smaller, but more stable group less influenced by promotions and experiences, and seeking a reputable and safe gambling experience. As the majority of Internet gamblers use multiple accounts, more universal responsible gambling strategies are needed to assist gamblers to track and control their expenditure to reduce risks of harm. © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Optimal sampling strategy for data mining

International Nuclear Information System (INIS)

Ghaffar, A.; Shahbaz, M.; Mahmood, W.

2013-01-01

Latest technology like Internet, corporate intranets, data warehouses, ERP's, satellites, digital sensors, embedded systems, mobiles networks all are generating such a massive amount of data that it is getting very difficult to analyze and understand all these data, even using data mining tools. Huge datasets are becoming a difficult challenge for classification algorithms. With increasing amounts of data, data mining algorithms are getting slower and analysis is getting less interactive. Sampling can be a solution. Using a fraction of computing resources, Sampling can often provide same level of accuracy. The process of sampling requires much care because there are many factors involved in the determination of correct sample size. The approach proposed in this paper tries to find a solution to this problem. Based on a statistical formula, after setting some parameters, it returns a sample size called s ufficient sample size , which is then selected through probability sampling. Results indicate the usefulness of this technique in coping with the problem of huge datasets. (author)

Non-erotic thoughts, attentional focus, and sexual problems in a community sample.

Science.gov (United States)

Nelson, Andrea L; Purdon, Christine

2011-04-01

According to Barlow's model of sexual dysfunction, anxiety in sexual situations leads to attentional focus on sexual performance at the expense of erotic cues, which compromises sexual arousal. This negative experience will enhance anxiety in future sexual situations, and non-erotic thoughts (NETs) relevant to performance will receive attentional priority. Previous research with student samples (Purdon & Holdaway, 2006; Purdon & Watson, 2010) has found that people experience many types of NETs in addition to performance-relevant thoughts, and that, consistent with Barlow's model, the frequency of and anxiety evoked by these thoughts is positively associated with sexual problems. Extending this previous work, the current study found that, in a community sample of women (N = 81) and men (N = 72) in long-term relationships, women were more likely to report body image concerns and external consequences of the sexual activity, while men were more likely to report performance-related concerns. Equally likely among men and women were thoughts about emotional consequences of the sexual activity. Regardless of thought content, experiencing more frequent NETs was associated with more sexual problems in both women and men. Moreover, as per Barlow's model, greater negative affect in anticipation of and during sexual activity predicted greater frequency of NETs and greater anxiety in response to NETs was associated with greater difficulty dismissing the thoughts. However, greater difficulty in refocusing on erotic thoughts during sexual activity uniquely predicted more sexual problems above the frequency and dismissability of NETs. Together, these data support the cognitive interference mechanism implicated by Barlow's causal model of sexual dysfunction and have implications for the treatment of sexual problems.

Gender differences in the associations of gambling activities and suicidal behaviors with problem gambling in a nationally representative French sample.

Science.gov (United States)

Husky, Mathilde M; Michel, Grégory; Richard, Jean-Baptiste; Guignard, Romain; Beck, François

2015-06-01

The objectives of the present study are to describe gender differences in factors associated with moderate risk and problem gambling. Data were extracted from the 2010 Health Barometer, a large survey on a representative sample of the general population aged 15-85 years living in France (n=27,653), carried out by the National Institute for Health Promotion and Health Education. Data were collected between October 2009 and July 2010. A computer-assisted telephone interview system was used. The findings indicate that men are three times more likely to experience problems with gambling. Men and women have different patterns of gambling activities. Men were more involved with Rapido, internet gambling, sports and racetrack betting, poker, and casino tables, whereas women gambled more often on scratch games. Both men and women engaging in immediate reward games were significantly more likely to experience difficulties with gambling. This association, however, was stronger in women. Furthermore, suicidal ideation and behaviors were more likely to be associated with gambling problems in women as compared to men. The study underscores the importance of considering gender-related differences in the study of gambling behaviors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Radiocarbon dating of interlaboratory check samples

International Nuclear Information System (INIS)

Blake, W.

1983-01-01

This note presents the results of a series of interlaboratory age determinations in which the Geological Survey of Canada's Radiocarbon Dating Laboratory has been involved. There is good agreement between laboratories, although there may be other problems related to the interpretation of individual samples

Students’ difficulties in probabilistic problem-solving

Science.gov (United States)

Arum, D. P.; Kusmayadi, T. A.; Pramudya, I.

2018-03-01

There are many errors can be identified when students solving mathematics problems, particularly in solving the probabilistic problem. This present study aims to investigate students’ difficulties in solving the probabilistic problem. It focuses on analyzing and describing students errors during solving the problem. This research used the qualitative method with case study strategy. The subjects in this research involve ten students of 9th grade that were selected by purposive sampling. Data in this research involve students’ probabilistic problem-solving result and recorded interview regarding students’ difficulties in solving the problem. Those data were analyzed descriptively using Miles and Huberman steps. The results show that students have difficulties in solving the probabilistic problem and can be divided into three categories. First difficulties relate to students’ difficulties in understanding the probabilistic problem. Second, students’ difficulties in choosing and using appropriate strategies for solving the problem. Third, students’ difficulties with the computational process in solving the problem. Based on the result seems that students still have difficulties in solving the probabilistic problem. It means that students have not able to use their knowledge and ability for responding probabilistic problem yet. Therefore, it is important for mathematics teachers to plan probabilistic learning which could optimize students probabilistic thinking ability.

Recent bibliography on analytical and sampling problems of a PWR primary coolant Suppl. 4

International Nuclear Information System (INIS)

Illy, H.

1986-09-01

The 4th supplement of a bibliographical series comprising the analytical and sampling problems of the primary coolant of PWR type reactors covers the literature from 1985 up to July 1986 (220 items). References are listed according to the following topics: boric acid; chloride, chlorine; general; hydrogen isotopes; iodine; iodide; noble gases; oxygen; other elements; radiation monitoring; reactor safety; sampling; water chemistry. (V.N.)

Triple solutions for a Dirichlet boundary value problem involving a perturbed discrete p(k-Laplacian operator

Directory of Open Access Journals (Sweden)

Khaleghi Moghadam Mohsen

2017-08-01

Full Text Available Triple solutions are obtained for a discrete problem involving a nonlinearly perturbed one-dimensional p(k-Laplacian operator and satisfying Dirichlet boundary conditions. The methods for existence rely on a Ricceri-local minimum theorem for differentiable functionals. Several examples are included to illustrate the main results.

Factors involved in making post-performance judgments in mathematics problem-solving.

Science.gov (United States)

García Fernández, Trinidad; Kroesbergen, Evelyn; Rodríguez Pérez, Celestino; González-Castro, Paloma; González-Pienda, Julio A

2015-01-01

This study examines the impact of executive functions, affective-motivational variables related to mathematics, mathematics achievement and task characteristics on fifth and sixth graders’ calibration accuracy after completing two mathematical problems. A sample of 188 students took part in the study. They were divided into two groups as function of their judgment accuracy after completing the two tasks (accurate= 79, inaccurate= 109). Differences between these groups were examined. The discriminative value of these variables to predict group membership was analyzed, as well as the effect of age, gender, and grade level. The results indicated that accurate students showed better levels of executive functioning, and more positive feelings, beliefs, and motivation related to mathematics. They also spent more time on the tasks. Mathematics achievement, perceived usefulness of mathematics, and time spent on Task 1 significantly predicted group membership, classifying 71.3% of the sample correctly. These results support the relationship between academic achievement and calibration accuracy, suggesting the need to consider a wide range of factors when explaining performance judgments.

Sample problems for the novice user of the AMPX-II system

International Nuclear Information System (INIS)

Ford, W.E. III; Roussin, R.W.; Petrie, L.M.; Diggs, B.R.; Comolander, H.E.

1979-01-01

Contents of the IBM version of the APMX system distributed by the Radiation Shielding Information Center (APMX-II) are described. Sample problems which demonstrate the procedure for implementing AMPX-II modules to generate point cross sections; generate multigroup neutron, photon production, and photon interaction cross sections for various transport codes; collapse multigroup cross sections; check, edit, and punch multigroup cross sections; and execute a one-dimensional discrete ordinates transport calculation are detailed. 25 figures, 9 tables

A direct sampling method to an inverse medium scattering problem

KAUST Repository

Ito, Kazufumi

2012-01-10

In this work we present a novel sampling method for time harmonic inverse medium scattering problems. It provides a simple tool to directly estimate the shape of the unknown scatterers (inhomogeneous media), and it is applicable even when the measured data are only available for one or two incident directions. A mathematical derivation is provided for its validation. Two- and three-dimensional numerical simulations are presented, which show that the method is accurate even with a few sets of scattered field data, computationally efficient, and very robust with respect to noises in the data. © 2012 IOP Publishing Ltd.

Solution of adsorption problems involving steep moving profiles

DEFF Research Database (Denmark)

Kiil, Søren; Bhatia, Suresh K.

1998-01-01

The moving finite element collocation method proposed by Kiil et al. (1995) for solution of problems with steep gradients is further developed to solve transient problems arising in the field of adsorption. The technique is applied to a model of adsorption in solids with bidisperse pore structures....... Numerical solutions were found to match the analytical solution when it exists (i.e. when the adsorption isotherm is linear). Results of this application study show that the method is simple yet sufficiently accurate for use in adsorption problems with steep moving gradients, where global collocation...

Local entropy as a measure for sampling solutions in constraint satisfaction problems

International Nuclear Information System (INIS)

Baldassi, Carlo; Ingrosso, Alessandro; Lucibello, Carlo; Saglietti, Luca; Zecchina, Riccardo

2016-01-01

We introduce a novel entropy-driven Monte Carlo (EdMC) strategy to efficiently sample solutions of random constraint satisfaction problems (CSPs). First, we extend a recent result that, using a large-deviation analysis, shows that the geometry of the space of solutions of the binary perceptron learning problem (a prototypical CSP), contains regions of very high-density of solutions. Despite being sub-dominant, these regions can be found by optimizing a local entropy measure. Building on these results, we construct a fast solver that relies exclusively on a local entropy estimate, and can be applied to general CSPs. We describe its performance not only for the perceptron learning problem but also for the random K-satisfiabilty problem (another prototypical CSP with a radically different structure), and show numerically that a simple zero-temperature Metropolis search in the smooth local entropy landscape can reach sub-dominant clusters of optimal solutions in a small number of steps, while standard Simulated Annealing either requires extremely long cooling procedures or just fails. We also discuss how the EdMC can heuristically be made even more efficient for the cases we studied. (paper: disordered systems, classical and quantum)

Blaming the Victim: The Problem of Evaluation Design and Federal Involvement, and Reinforcing World Views in Education.

Science.gov (United States)

Fetterman, David M.

1981-01-01

Shows how evaluation design and federal involvement in Youth Employment Demonstration Projects unintentionally cause a negative appraisal. Indicates the problem stems from interaction of the contract research corporation, the educational research establishment, and the federal bureaucracy, rather than a specific methodology or bureaucratic…

Hybrid nested sampling algorithm for Bayesian model selection applied to inverse subsurface flow problems

International Nuclear Information System (INIS)

Elsheikh, Ahmed H.; Wheeler, Mary F.; Hoteit, Ibrahim

2014-01-01

A Hybrid Nested Sampling (HNS) algorithm is proposed for efficient Bayesian model calibration and prior model selection. The proposed algorithm combines, Nested Sampling (NS) algorithm, Hybrid Monte Carlo (HMC) sampling and gradient estimation using Stochastic Ensemble Method (SEM). NS is an efficient sampling algorithm that can be used for Bayesian calibration and estimating the Bayesian evidence for prior model selection. Nested sampling has the advantage of computational feasibility. Within the nested sampling algorithm, a constrained sampling step is performed. For this step, we utilize HMC to reduce the correlation between successive sampled states. HMC relies on the gradient of the logarithm of the posterior distribution, which we estimate using a stochastic ensemble method based on an ensemble of directional derivatives. SEM only requires forward model runs and the simulator is then used as a black box and no adjoint code is needed. The developed HNS algorithm is successfully applied for Bayesian calibration and prior model selection of several nonlinear subsurface flow problems

Hybrid nested sampling algorithm for Bayesian model selection applied to inverse subsurface flow problems

Energy Technology Data Exchange (ETDEWEB)

Elsheikh, Ahmed H., E-mail: aelsheikh@ices.utexas.edu [Institute for Computational Engineering and Sciences (ICES), University of Texas at Austin, TX (United States); Institute of Petroleum Engineering, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Wheeler, Mary F. [Institute for Computational Engineering and Sciences (ICES), University of Texas at Austin, TX (United States); Hoteit, Ibrahim [Department of Earth Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal (Saudi Arabia)

2014-02-01

A Hybrid Nested Sampling (HNS) algorithm is proposed for efficient Bayesian model calibration and prior model selection. The proposed algorithm combines, Nested Sampling (NS) algorithm, Hybrid Monte Carlo (HMC) sampling and gradient estimation using Stochastic Ensemble Method (SEM). NS is an efficient sampling algorithm that can be used for Bayesian calibration and estimating the Bayesian evidence for prior model selection. Nested sampling has the advantage of computational feasibility. Within the nested sampling algorithm, a constrained sampling step is performed. For this step, we utilize HMC to reduce the correlation between successive sampled states. HMC relies on the gradient of the logarithm of the posterior distribution, which we estimate using a stochastic ensemble method based on an ensemble of directional derivatives. SEM only requires forward model runs and the simulator is then used as a black box and no adjoint code is needed. The developed HNS algorithm is successfully applied for Bayesian calibration and prior model selection of several nonlinear subsurface flow problems.

Hybrid nested sampling algorithm for Bayesian model selection applied to inverse subsurface flow problems

KAUST Repository

Elsheikh, Ahmed H.

2014-02-01

A Hybrid Nested Sampling (HNS) algorithm is proposed for efficient Bayesian model calibration and prior model selection. The proposed algorithm combines, Nested Sampling (NS) algorithm, Hybrid Monte Carlo (HMC) sampling and gradient estimation using Stochastic Ensemble Method (SEM). NS is an efficient sampling algorithm that can be used for Bayesian calibration and estimating the Bayesian evidence for prior model selection. Nested sampling has the advantage of computational feasibility. Within the nested sampling algorithm, a constrained sampling step is performed. For this step, we utilize HMC to reduce the correlation between successive sampled states. HMC relies on the gradient of the logarithm of the posterior distribution, which we estimate using a stochastic ensemble method based on an ensemble of directional derivatives. SEM only requires forward model runs and the simulator is then used as a black box and no adjoint code is needed. The developed HNS algorithm is successfully applied for Bayesian calibration and prior model selection of several nonlinear subsurface flow problems. © 2013 Elsevier Inc.

Problem based learning and involvement in off campus organization enhance students’ critical participation behavior

Directory of Open Access Journals (Sweden)

Endang Lestari

2009-09-01

Full Text Available Aim Developing students’ critical thinking and critical participation in solving patients’ as well as a community’s problem should become the concern of medical education. This study aimed to identify several factors related to medical students’ critical participation behavior.Methods The subjects consisted of students of Sultan Agung Medical School (Unissula, year entry 2005, 2006, and 2007. Critical participation behavior was assessed using modified EMI: Critical Thinking Disposition Assessment. Relative risks (RR were calculated using Cox regression analysis with constant time.Results 64,6% (388 out of 600 of the students participated in this study. Those who were involved in PBL for two and three years, rather than one year, had twice as high good critical thinking behavior [adjusted relative risk (RR = 2.07; 95% confidence interval (CI = 1.37–3.14; and RR = 2.33; 95% CI = 155–3.49, respectively.] Students who were more involved in off-campus organizations had a good critical participation behavior; 75% higher than those who were not involved in off-campus organizations (RR = 1.75; 95% CI = 0.99–3.11.Conclusion Besides involving in PBL learning approach, students should be motivated to be involved in off-campus organizations in order to improve their critical participation behavior (Med J Indones 2009;18:215-20Key words: critical participation behavior, PBL, off-campus organization

A novel fluorescent in situ hybridization technique for detection of Rickettsia spp. in archival samples

DEFF Research Database (Denmark)

Svendsen, Claus Bo; Boye, Mette; Struve, Carsten

2009-01-01

A novel, sensitive and specific method for detecting Rickettsia spp. in archival samples is described. The method involves the use of fluorescently marked oligonucleotide probes for in situ hybridization. Specific hybridization of Ricekttsia was found without problems of cross-reactions with bact......A novel, sensitive and specific method for detecting Rickettsia spp. in archival samples is described. The method involves the use of fluorescently marked oligonucleotide probes for in situ hybridization. Specific hybridization of Ricekttsia was found without problems of cross...

The semantic system is involved in mathematical problem solving.

Science.gov (United States)

Zhou, Xinlin; Li, Mengyi; Li, Leinian; Zhang, Yiyun; Cui, Jiaxin; Liu, Jie; Chen, Chuansheng

2018-02-01

Numerous studies have shown that the brain regions around bilateral intraparietal cortex are critical for number processing and arithmetical computation. However, the neural circuits for more advanced mathematics such as mathematical problem solving (with little routine arithmetical computation) remain unclear. Using functional magnetic resonance imaging (fMRI), this study (N = 24 undergraduate students) compared neural bases of mathematical problem solving (i.e., number series completion, mathematical word problem solving, and geometric problem solving) and arithmetical computation. Direct subject- and item-wise comparisons revealed that mathematical problem solving typically had greater activation than arithmetical computation in all 7 regions of the semantic system (which was based on a meta-analysis of 120 functional neuroimaging studies on semantic processing). Arithmetical computation typically had greater activation in the supplementary motor area and left precentral gyrus. The results suggest that the semantic system in the brain supports mathematical problem solving. Copyright © 2017 Elsevier Inc. All rights reserved.

Sustained impact of inattention and hyperactivity-impulsivity on peer problems: mediating roles of prosocial skills and conduct problems in a community sample of children.

Science.gov (United States)

Andrade, Brendan F; Tannock, Rosemary

2014-06-01

This prospective 2-year longitudinal study tested whether inattentive and hyperactive/impulsive symptom dimensions predicted future peer problems, when accounting for concurrent conduct problems and prosocial skills. A community sample of 492 children (49 % female) who ranged in age from 6 to 10 years (M = 8.6, SD = .93) was recruited. Teacher reports of children's inattention, and hyperactivity/impulsivity symptoms, conduct problems, prosocial skills and peer problems were collected in two consecutive school years. Elevated inattention and hyperactivity/impulsivity in Year-1 predicted greater peer problems in Year-2. Conduct problems in the first and second years of the study were associated with more peer problems, and explained a portion of the relationship between inattention and hyperactivity/impulsivity with peer problems. However, prosocial skills were associated with fewer peer problems in children with elevated inattention and hyperactivity/impulsivity. Inattention and hyperactivity/impulsivity have negative effects on children's peer functioning after 1-year, but concurrent conduct problems and prosocial skills have important and opposing impacts on these associations.

Health literacy, numeracy, and other characteristics associated with hospitalized patients' preferences for involvement in decision-making

OpenAIRE

Goggins, KM; Wallston, KA; Nwosu, S; Schildcrout, JS; Castel, L; Kripalani, S

2014-01-01

Little research has examined the association of health literacy and numeracy with patients' preferred involvement in the problem-solving and decision-making process in the hospital. Using a sample of 1,249 patients hospitalized with cardiovascular disease from the Vanderbilt Inpatient Cohort Study (VICS), we assessed patients' preferred level of involvement using responses to two scenarios of differing symptom severity from the Problem-Solving Decision-Making (PSDM) Scale. Using multivariable...

Problematic Technology Use in a clinical sample of children and adolescents. Personality and behavioral problems associated.

Science.gov (United States)

Alonso, Cristina; Romero, Estrella

2017-03-01

In parallel to the rapid growth of access to new technologies (NT) there has been an increase in the problematic use of the same, especially among children and adolescents. Although research in this field is increasing, the studies have mainly been developed in the community, and the characteristics associated with the problematic use of NT are unknown in samples that require clinical care. Therefore, the aim of this study is to analyze the relationship between problematic use of video games (UPV) and Internet (UPI) and personality traits and behavior problems in a clinical sample of children and adolescents. The sample consists of 88 patients who were examined in the clinical psychology consultation in the Mental Health Unit for Children and Adolescents of the University Hospital of Santiago de Compostela. Data were obtained from self-reports and rating scales filled out by parents. 31.8% of the participants present UPI and 18.2%, UPV. The children and adolescents with UPNT have lower levels of Openness to experience, Conscientiousness and Agreeableness and higher levels of Emotional instability, global Impulsivity and Externalizing behavior problems, as well as Attention and Thought problems. UPNT is a problem that emerges as an important issue in clinical care for children and adolescents, so its study in child and youth care units is needed. Understanding the psychopathological profile of children and adolescents with UPNT will allow for the development of differential and more specific interventions.

Jocks, gender, race, and adolescent problem drinking.

Science.gov (United States)

Miller, Kathleen E; Hoffman, Joseph H; Barnes, Grace M; Farrell, Michael P; Sabo, Don; Melnick, Merrill J

2003-01-01

Alcohol remains the drug of choice for many adolescents; however, the nature of the relationship between athletic involvement and alcohol misuse remains ambiguous. In this article, we used a longitudinal sample of over 600 Western New York adolescents and their families to explore the gender-specific and race-specific relationships between identification with the "jock" label and adolescent alcohol consumption, specifically problem drinking. Operationalization of problem drinking included frequency measures of heavy drinking, binge drinking, and social problems related to alcohol (e.g., trouble with family, friends, school officials over drinking). Self-identified adolescent "jocks" were more likely to engage in problem drinking than their non-jock counterparts, even after controlling for gender, age, race, socioeconomic status, physical maturity, social maturity, and frequency of athletic activity. Jock identity was strongly associated with higher binge drinking frequency in Black adolescent girls. This study underscores the need to distinguish between objective and subjective meanings of athletic involvement when assessing the relationship between sport and adolescent health-risk behavior.

Geostatistical Sampling Methods for Efficient Uncertainty Analysis in Flow and Transport Problems

Science.gov (United States)

Liodakis, Stylianos; Kyriakidis, Phaedon; Gaganis, Petros

2015-04-01

In hydrogeological applications involving flow and transport of in heterogeneous porous media the spatial distribution of hydraulic conductivity is often parameterized in terms of a lognormal random field based on a histogram and variogram model inferred from data and/or synthesized from relevant knowledge. Realizations of simulated conductivity fields are then generated using geostatistical simulation involving simple random (SR) sampling and are subsequently used as inputs to physically-based simulators of flow and transport in a Monte Carlo framework for evaluating the uncertainty in the spatial distribution of solute concentration due to the uncertainty in the spatial distribution of hydraulic con- ductivity [1]. Realistic uncertainty analysis, however, calls for a large number of simulated concentration fields; hence, can become expensive in terms of both time and computer re- sources. A more efficient alternative to SR sampling is Latin hypercube (LH) sampling, a special case of stratified random sampling, which yields a more representative distribution of simulated attribute values with fewer realizations [2]. Here, term representative implies realizations spanning efficiently the range of possible conductivity values corresponding to the lognormal random field. In this work we investigate the efficiency of alternative methods to classical LH sampling within the context of simulation of flow and transport in a heterogeneous porous medium. More precisely, we consider the stratified likelihood (SL) sampling method of [3], in which attribute realizations are generated using the polar simulation method by exploring the geometrical properties of the multivariate Gaussian distribution function. In addition, we propose a more efficient version of the above method, here termed minimum energy (ME) sampling, whereby a set of N representative conductivity realizations at M locations is constructed by: (i) generating a representative set of N points distributed on the

The direct effects of inattention and hyperactivity/impulsivity on peer problems and mediating roles of prosocial and conduct problem behaviors in a community sample of children.

Science.gov (United States)

Andrade, Brendan F; Tannock, Rosemary

2013-11-01

This study tested whether children's symptoms of inattention and hyperactivity/impulsivity were associated with peer problems and whether these associations were mediated by conduct problems and prosocial behaviors. A community sample of 500 children, including 245 boys and 255 girls, who ranged in age from 6 to 9 years (M = 7.6, SD = 0.91) were recruited. Teachers' report of children's inattention, hyperactivity/impulsivity, conduct problems, prosocial behaviors, and peer problems was collected. Symptoms of inattention and hyperactivity/impulsivity were significantly positively associated with peer problems. Conduct problems were associated with more peer problems and prosocial behaviors with less peer problems. Conduct problems and prosocial behaviors partially mediated the association between hyperactivity/impulsivity and peer problems and fully mediated the inattention-peer problems association. Findings show that prosocial behaviors and conduct problems are important variables that account for some of the negative impact of symptoms of inattention and hyperactivity/impulsivity on peer functioning.

The Role of Marital Discord and Parenting in Relations between Parental Problem Drinking and Child Adjustment

Science.gov (United States)

Keller, Peggy S.; Cummings, E. Mark; Davies, Patrick T.

2005-01-01

Background: Research suggests that children exposed to parental drinking problems are at risk for maladjustment. However, the potential impact of drinking problems in a community sample and the processes involved in the relationship between parental drinking and child outcomes have rarely been examined. Method: A community sample of 235 mothers…

Recent bibliography on analytical and sampling problems of a PWR primary coolant Suppl. 3

International Nuclear Information System (INIS)

Illy, H.

1985-03-01

The present supplement to the bibliography on analytical and sampling problems of PWR primary coolant covers the literature published in 1984 and includes some references overlooked in the previous volumes dealing with the publications of the last 10 years. References are devided into topics characterized by the following headlines: boric acid; chloride; chlorine; carbon dioxide; general; gas analysis; hydrogen isotopes; iodine; iodide; nitrogen; noble gases and radium; ammonia; ammonium; oxygen; other elements; radiation monitoring; reactor safety; sampling; water chemistry. Under a given subject bibliographical information is listed in alphabetical order of the authors. (V.N.)

Polygenic scores predict alcohol problems in an independent sample and show moderation by the environment.

Science.gov (United States)

Salvatore, Jessica E; Aliev, Fazil; Edwards, Alexis C; Evans, David M; Macleod, John; Hickman, Matthew; Lewis, Glyn; Kendler, Kenneth S; Loukola, Anu; Korhonen, Tellervo; Latvala, Antti; Rose, Richard J; Kaprio, Jaakko; Dick, Danielle M

2014-04-10

Alcohol problems represent a classic example of a complex behavioral outcome that is likely influenced by many genes of small effect. A polygenic approach, which examines aggregate measured genetic effects, can have predictive power in cases where individual genes or genetic variants do not. In the current study, we first tested whether polygenic risk for alcohol problems-derived from genome-wide association estimates of an alcohol problems factor score from the age 18 assessment of the Avon Longitudinal Study of Parents and Children (ALSPAC; n = 4304 individuals of European descent; 57% female)-predicted alcohol problems earlier in development (age 14) in an independent sample (FinnTwin12; n = 1162; 53% female). We then tested whether environmental factors (parental knowledge and peer deviance) moderated polygenic risk to predict alcohol problems in the FinnTwin12 sample. We found evidence for both polygenic association and for additive polygene-environment interaction. Higher polygenic scores predicted a greater number of alcohol problems (range of Pearson partial correlations 0.07-0.08, all p-values ≤ 0.01). Moreover, genetic influences were significantly more pronounced under conditions of low parental knowledge or high peer deviance (unstandardized regression coefficients (b), p-values (p), and percent of variance (R2) accounted for by interaction terms: b = 1.54, p = 0.02, R2 = 0.33%; b = 0.94, p = 0.04, R2 = 0.30%, respectively). Supplementary set-based analyses indicated that the individual top single nucleotide polymorphisms (SNPs) contributing to the polygenic scores were not individually enriched for gene-environment interaction. Although the magnitude of the observed effects are small, this study illustrates the usefulness of polygenic approaches for understanding the pathways by which measured genetic predispositions come together with environmental factors to predict complex behavioral outcomes.

Condom-related problems among a racially diverse sample of young men who have sex with men.

Science.gov (United States)

Du Bois, Steve N; Emerson, Erin; Mustanski, Brian

2011-10-01

We described frequencies of condom-related problems in a racially diverse sample of young men who have sex with men (YMSM), and tested these condom-related problems as an explanation for racial disparities in HIV rates among YMSM. Participants were 119 YMSM from a longitudinal study of sexual minority health behaviors. Almost all participants (95.4%) experienced at least one condom error. On average, African American and non-African American YMSM experienced the same number of recent condom-related problems. Therefore, differences in condom-related problems are unlikely to explain racial disparities in HIV rates among YMSM. When serving YMSM, providers should both promote condom use and explain steps to correct condom use.

A support vector density-based importance sampling for reliability assessment

International Nuclear Information System (INIS)

Dai, Hongzhe; Zhang, Hao; Wang, Wei

2012-01-01

An importance sampling method based on the adaptive Markov chain simulation and support vector density estimation is developed in this paper for efficient structural reliability assessment. The methodology involves the generation of samples that can adaptively populate the important region by the adaptive Metropolis algorithm, and the construction of importance sampling density by support vector density. The use of the adaptive Metropolis algorithm may effectively improve the convergence and stability of the classical Markov chain simulation. The support vector density can approximate the sampling density with fewer samples in comparison to the conventional kernel density estimation. The proposed importance sampling method can effectively reduce the number of structural analysis required for achieving a given accuracy. Examples involving both numerical and practical structural problems are given to illustrate the application and efficiency of the proposed methodology.

Convergence rates and finite-dimensional approximations for nonlinear ill-posed problems involving monotone operators in Banach spaces

International Nuclear Information System (INIS)

Nguyen Buong.

1992-11-01

The purpose of this paper is to investigate convergence rates for an operator version of Tikhonov regularization constructed by dual mapping for nonlinear ill-posed problems involving monotone operators in real reflective Banach spaces. The obtained results are considered in combination with finite-dimensional approximations for the space. An example is considered for illustration. (author). 15 refs

Food insecurity and mental health problems among a community sample of young adults.

Science.gov (United States)

Pryor, Laura; Lioret, Sandrine; van der Waerden, Judith; Fombonne, Éric; Falissard, Bruno; Melchior, Maria

2016-08-01

Food insecurity has been found to be related to anxiety and depression; however, the association with other psychiatric disorders, particularly among young adults, is not well known. We examined whether food insecurity is independently associated with four common mental health problems among a community sample of young adults in France. Data are from the TEMPO longitudinal cohort study. In 1991, participants' parents provided information on health and family socioeconomic characteristics. In 2011, participants' (18-35 years) reported food insecurity, mental health symptoms, and socioeconomic conditions (n = 1214). Mental health problems ascertained included major depressive episode, suicidal ideation, attention deficit and hyperactivity disorder, and substance abuse and/or dependence (nicotine, alcohol and cannabis). Cross-sectional associations between food insecurity and mental health problems were tested using modified Poisson regressions, weighted by inverse probability weights (IPW) of exposure. This makes food insecure and not food insecure participants comparable on all characteristics including socioeconomic factors and past mental health problems. 8.5 % of young adults were food insecure. In IPW-controlled analyses, food insecurity was associated with increased levels of depression (RR = 2.01, 95 % CI 1.01-4.02), suicidal ideation (RR = 3.23, 95 % CI 1.55-6.75) and substance use problems (RR = 1.68, 95 % CI 1.15-2.46). Food insecurity co-occurs with depression, suicidal ideation and substance use problems in young adulthood. Our findings suggest that reductions in food insecurity during this important life period may help prevent mental health problems. Policies aiming to alleviate food insecurity should also address individuals' psychiatric problems, to prevent a lifelong vicious circle of poor mental health and low socioeconomic attainment.

Efficient Monte Carlo sampling of inverse problems using a neural network-based forward—applied to GPR crosshole traveltime inversion

Science.gov (United States)

Hansen, T. M.; Cordua, K. S.

2017-12-01

Probabilistically formulated inverse problems can be solved using Monte Carlo-based sampling methods. In principle, both advanced prior information, based on for example, complex geostatistical models and non-linear forward models can be considered using such methods. However, Monte Carlo methods may be associated with huge computational costs that, in practice, limit their application. This is not least due to the computational requirements related to solving the forward problem, where the physical forward response of some earth model has to be evaluated. Here, it is suggested to replace a numerical complex evaluation of the forward problem, with a trained neural network that can be evaluated very fast. This will introduce a modeling error that is quantified probabilistically such that it can be accounted for during inversion. This allows a very fast and efficient Monte Carlo sampling of the solution to an inverse problem. We demonstrate the methodology for first arrival traveltime inversion of crosshole ground penetrating radar data. An accurate forward model, based on 2-D full-waveform modeling followed by automatic traveltime picking, is replaced by a fast neural network. This provides a sampling algorithm three orders of magnitude faster than using the accurate and computationally expensive forward model, and also considerably faster and more accurate (i.e. with better resolution), than commonly used approximate forward models. The methodology has the potential to dramatically change the complexity of non-linear and non-Gaussian inverse problems that have to be solved using Monte Carlo sampling techniques.

Efficient Bayesian parameter estimation with implicit sampling and surrogate modeling for a vadose zone hydrological problem

Science.gov (United States)

Liu, Y.; Pau, G. S. H.; Finsterle, S.

2015-12-01

Parameter inversion involves inferring the model parameter values based on sparse observations of some observables. To infer the posterior probability distributions of the parameters, Markov chain Monte Carlo (MCMC) methods are typically used. However, the large number of forward simulations needed and limited computational resources limit the complexity of the hydrological model we can use in these methods. In view of this, we studied the implicit sampling (IS) method, an efficient importance sampling technique that generates samples in the high-probability region of the posterior distribution and thus reduces the number of forward simulations that we need to run. For a pilot-point inversion of a heterogeneous permeability field based on a synthetic ponded infiltration experiment simu­lated with TOUGH2 (a subsurface modeling code), we showed that IS with linear map provides an accurate Bayesian description of the parameterized permeability field at the pilot points with just approximately 500 forward simulations. We further studied the use of surrogate models to improve the computational efficiency of parameter inversion. We implemented two reduced-order models (ROMs) for the TOUGH2 forward model. One is based on polynomial chaos expansion (PCE), of which the coefficients are obtained using the sparse Bayesian learning technique to mitigate the "curse of dimensionality" of the PCE terms. The other model is Gaussian process regression (GPR) for which different covariance, likelihood and inference models are considered. Preliminary results indicate that ROMs constructed based on the prior parameter space perform poorly. It is thus impractical to replace this hydrological model by a ROM directly in a MCMC method. However, the IS method can work with a ROM constructed for parameters in the close vicinity of the maximum a posteriori probability (MAP) estimate. We will discuss the accuracy and computational efficiency of using ROMs in the implicit sampling procedure

SIPPI: A Matlab toolbox for sampling the solution to inverse problems with complex prior information

DEFF Research Database (Denmark)

Hansen, Thomas Mejer; Cordua, Knud Skou; Looms, Majken Caroline

2013-01-01

We present an application of the SIPPI Matlab toolbox, to obtain a sample from the a posteriori probability density function for the classical tomographic inversion problem. We consider a number of different forward models, linear and non-linear, such as ray based forward models that rely...

Family doctors' involvement with families in Estonia

Directory of Open Access Journals (Sweden)

Lember Margus

2004-10-01

Full Text Available Abstract Background Family doctors should care for individuals in the context of their family. Family has a powerful influence on health and illness and family interventions have been shown to improve health outcomes for a variety of health problems. The aim of the study was to investigate the Estonian family doctors' (FD attitudes to the patients' family-related issues in their work: to explore the degree of FDs involvement in family matters, their preparedness for management of family-related issues and their self-assessment of the ability to manage different family-related problems. Methods A random sample (n = 236 of all FDs in Estonia was investigated using a postal questionnaire. Altogether 151 FDs responded to the questionnaire (response rate 64%, while five of them were excluded as they did not actually work as FDs. Results Of the respondents, 90% thought that in managing the health problems of patients FDs should communicate and cooperate with family members. Although most of the family doctors agreed that modifying of the health damaging risk factors (smoking, alcohol and drug abuse of their patients and families is their task, one third of them felt that dealing with these problems is ineffective, or perceived themselves as poorly prepared or having too little time for such activities. Of the respondents, 58% (n = 83 were of the opinion that they could modify also relationship problems. Conclusions Estonian family doctors are favourably disposed to involvement in family-related problems, however, they need some additional training, especially in the field of relationship management.

Energy-Aware Path Planning for UAS Persistent Sampling and Surveillance

Science.gov (United States)

Shaw-Cortez, Wenceslao

The focus of this work is to develop an energy-aware path planning algorithm that maximizes UAS endurance, while performing sampling and surveillance missions in a known, stationary wind environment. The energy-aware aspect is specifically tailored to extract energy from the wind to reduce thrust use, thereby increasing aircraft endurance. Wind energy extraction is performed by static soaring and dynamic soaring. Static soaring involves using upward wind currents to increase altitude and potential energy. Dynamic soaring involves taking advantage of wind gradients to exchange potential and kinetic energy. The path planning algorithm developed in this work uses optimization to combine these soaring trajectories with the overarching sampling and surveillance mission. The path planning algorithm uses a simplified aircraft model to tractably optimize soaring trajectories. This aircraft model is presented and along with the derivation of the equations of motion. A nonlinear program is used to create the soaring trajectories based on a given optimization problem. This optimization problem is defined using a heuristic decision tree, which defines appropriate problems given a sampling and surveillance mission and a wind model. Simulations are performed to assess the path planning algorithm. The results are used to identify properties of soaring trajectories as well as to determine what wind conditions support minimal thrust soaring. Additional results show how the path planning algorithm can be tuned between maximizing aircraft endurance and performing the sampling and surveillance mission. A means of trajectory stitching is demonstrated to show how the periodic soaring segments can be combined together to provide a full solution to an infinite/long horizon problem.

Polygenic Scores Predict Alcohol Problems in an Independent Sample and Show Moderation by the Environment

Directory of Open Access Journals (Sweden)

Jessica E. Salvatore

2014-04-01

Full Text Available Alcohol problems represent a classic example of a complex behavioral outcome that is likely influenced by many genes of small effect. A polygenic approach, which examines aggregate measured genetic effects, can have predictive power in cases where individual genes or genetic variants do not. In the current study, we first tested whether polygenic risk for alcohol problems—derived from genome-wide association estimates of an alcohol problems factor score from the age 18 assessment of the Avon Longitudinal Study of Parents and Children (ALSPAC; n = 4304 individuals of European descent; 57% female—predicted alcohol problems earlier in development (age 14 in an independent sample (FinnTwin12; n = 1162; 53% female. We then tested whether environmental factors (parental knowledge and peer deviance moderated polygenic risk to predict alcohol problems in the FinnTwin12 sample. We found evidence for both polygenic association and for additive polygene-environment interaction. Higher polygenic scores predicted a greater number of alcohol problems (range of Pearson partial correlations 0.07–0.08, all p-values ≤ 0.01. Moreover, genetic influences were significantly more pronounced under conditions of low parental knowledge or high peer deviance (unstandardized regression coefficients (b, p-values (p, and percent of variance (R2 accounted for by interaction terms: b = 1.54, p = 0.02, R2 = 0.33%; b = 0.94, p = 0.04, R2 = 0.30%, respectively. Supplementary set-based analyses indicated that the individual top single nucleotide polymorphisms (SNPs contributing to the polygenic scores were not individually enriched for gene-environment interaction. Although the magnitude of the observed effects are small, this study illustrates the usefulness of polygenic approaches for understanding the pathways by which measured genetic predispositions come together with environmental factors to predict complex behavioral outcomes.

Quartz analysis in gravimetric sampling

International Nuclear Information System (INIS)

Rex, D.A.

1990-01-01

An overview of the methods employed in the assessment of quartz exposure is provided. The principles and some of the problems associated with each method is discussed. The methods reviewed include wet chemical methods, X-ray diffraction and infrared absorption of which the latter two methods are deemed appropriate for analysing quartz on personal gravimetric collected samples. The implications of combining area samples collected over a six month period, and performing only a single quartz analysis rather than separate analyses, are considered. Finally, various options open to mines with regard to their involvement with quartz analysis are also briefly discussed. 35 refs., 6 figs., 1 tab

The role of self-esteem in the development of psychiatric problems: a three-year prospective study in a clinical sample of adolescents.

Science.gov (United States)

Henriksen, Ingvild Oxås; Ranøyen, Ingunn; Indredavik, Marit Sæbø; Stenseng, Frode

2017-01-01

Self-esteem is fundamentally linked to mental health, but its' role in trajectories of psychiatric problems is unclear. In particular, few studies have addressed the role of self-esteem in the development of attention problems. Hence, we examined the role of global self-esteem in the development of symptoms of anxiety/depression and attention problems, simultaneously, in a clinical sample of adolescents while accounting for gender, therapy, and medication. Longitudinal data were obtained from a sample of 201 adolescents-aged 13-18-referred to the Department of Child and Adolescent Psychiatry in Trondheim, Norway. In the baseline study, self-esteem, and symptoms of anxiety/depression and attention problems were measured by means of self-report. Participants were reassessed 3 years later, with a participation rate of 77% in the clinical sample. Analyses showed that high self-esteem at baseline predicted fewer symptoms of both anxiety/depression and attention problems 3 years later after controlling for prior symptom levels, gender, therapy (or not), and medication. Results highlight the relevance of global self-esteem in the clinical practice, not only with regard to emotional problems, but also to attention problems. Implications for clinicians, parents, and others are discussed.

Recent bibliography on analytical and sampling problems of a PWR primary coolant Pt. 1

International Nuclear Information System (INIS)

Illy, H.

1981-12-01

The first bibliography on analytical and sampling problems of a PWR primary coolant (KFKI Report-1980-48) was published in 1980 and it covered the literature published in the previous 8-10 years. The present supplement reviews the subsequent literature up till December 1981. It also includes some references overlooked in the first volume. The serial numbers are continued from the first bibliography. (author)

Sleep Problems in Students of Elementary Schools in Kashan in 2013

Directory of Open Access Journals (Sweden)

FS Asgarian

2016-05-01

Full Text Available Introduction: Sleep problems are taken into account as a prevalent problem within school-age children that is normally ignored in spite of its high prevalence. Therefore, this study aimed to determine the frequency of sleep problems within elementary students in Kashan. Methods: This study is descriptive-cross sectional, in which 300 children (7-12 years old of Kashan elementary schools were randomly selected via cluster sampling method. The study instruments for data collection involved questions concerning children's age and sex as well as BEAR'S questionnaire, which were filled by the children's mothers. Moreover, the study data were analyzed by descriptive statistics method (mean and standard deviation, independent sample T-test was used to compare mean of sleep duration and Mann-Whitney u test was applied to evaluate the difference between age and sex groups. Results: Totally, 300 children participated in this study, among which 44.3% were boys and 55.7% were girls. The most common sleep problems involved nightmare and resistance against a wakening. Relative frequency of awakening during night was observed to be higher within boys than girls (p<0.05. Conclusion: High frequency of sleep problems in the current study may indicate the significance of taking sleep problems into consideration within students as well as informing healthy sleep patterns in order to promote knowledge level of parents via schools and parent-teacher meetings.

Problems of engineering education and their decision involving industry

OpenAIRE

R. P. Simonyants

2014-01-01

In Russia, the problems of engineering education are connected with political and economic upheavals of the late last century. At the same time, some leading engineering universities in Russia, such as the Bauman Moscow State Technical University (BMSTU) were resistant to the damaging effects of the crisis. But the methodology and experience of their effective work are insufficiently known.The problems of international engineering school development are also known. The first UNESCO World Repo...

Managing Ethical Problems in Qualitative Research Involving Vulnerable Populations, Using a Pilot Study

Directory of Open Access Journals (Sweden)

Evalina van Wijk RN, PhD

2013-02-01

Full Text Available The purpose of the researcher's study was to examine the meaning that intimate partners of female rape victims attached to their lived experiences after the rape. The conduct of qualitative research concerning non-offending partners of female rape victims, however, often involves multifaceted ethical and practical challenges, which can be managed through the use of pilot studies. The pilot study described in this report had three objectives. The first was to pretest and refine the proposed method for locating, accessing, and recruiting intimate partners of female rape victims, within the first two weeks after the rape, for participation in a six-month longitudinal study. The second objective was to identify and prevent all possible risk factors in the proposed recruitment and data collection methods that could harm the participants' safety during the main study. The third objective was to determine the feasibility of the main study, in terms of the limited financial and human resources available. The pilot phase was valuable in identifying ethical and methodological problems during the recruitment of participants and collection of data. It allowed for methodological adjustments prior to the main study and confirmed the feasibility of the overall research design. A pilot, pretesting phase is therefore seen as an essential component of a qualitative study involving a vulnerable population.

Identifying indicators of harmful and problem gambling in a Canadian sample through receiver operating characteristic analysis.

Science.gov (United States)

Quilty, Lena C; Avila Murati, Daniela; Bagby, R Michael

2014-03-01

Many gamblers would prefer to reduce gambling on their own rather than to adopt an abstinence approach within the context of a gambling treatment program. Yet responsible gambling guidelines lack quantifiable markers to guide gamblers in wagering safely. To address these issues, the current investigation implemented receiver operating characteristic (ROC) analysis to identify behavioral indicators of harmful and problem gambling. Gambling involvement was assessed in 503 participants (275 psychiatric outpatients and 228 community gamblers) with the Canadian Problem Gambling Index. Overall gambling frequency, duration, and expenditure were able to distinguish harmful and problematic gambling at a moderate level. Indicators of harmful gambling were generated for engagement in specific gambling activities: frequency of tickets and casino; duration of bingo, casino, and investments; and expenditures on bingo, casino, sports betting, games of skill, and investments. Indicators of problem gambling were similarly produced for frequency of tickets and casino, and expenditures on bingo, casino, games of skill, and investments. Logistic regression analyses revealed that overall gambling frequency uniquely predicted the presence of harmful and problem gambling. Furthermore, frequency indicators for tickets and casino uniquely predicted the presence of both harmful and problem gambling. Together, these findings contribute to the development of an empirically based method enabling the minimization of harmful or problem gambling through self-control rather than abstinence.

Music Taste Groups and Problem Behavior.

Science.gov (United States)

Mulder, Juul; Bogt, Tom Ter; Raaijmakers, Quinten; Vollebergh, Wilma

2007-04-01

Internalizing and externalizing problems differ by musical tastes. A high school-based sample of 4159 adolescents, representative of Dutch youth aged 12 to 16, reported on their personal and social characteristics, music preferences and social-psychological functioning, measured with the Youth Self-Report (YSR). Cluster analysis on their music preferences revealed six taste groups: Middle-of-the-road (MOR) listeners, Urban fans, Exclusive Rock fans, Rock-Pop fans, Elitists, and Omnivores. A seventh group of musically Low-Involved youth was added. Multivariate analyses revealed that when gender, age, parenting, school, and peer variables were controlled, Omnivores and fans within the Exclusive Rock groups showed relatively high scores on internalizing YSR measures, and social, thought and attention problems. Omnivores, Exclusive Rock, Rock-Pop and Urban fans reported more externalizing problem behavior. Belonging to the MOR group that highly appreciates the most popular, chart-based pop music appears to buffer problem behavior. Music taste group membership uniquely explains variance in both internalizing and externalizing problem behavior.

The association of ADHD and depression: Mediation by peer problems and parent-child difficulties in two complementary samples

Science.gov (United States)

Humphreys, Kathryn L.; Katz, Shaina J.; Lee, Steve S.; Hammen, Constance L.; Brennan, Patricia A.; Najman, Jake M.

2013-01-01

Children with attention-deficit/hyperactivity disorder (ADHD) are at increased risk for the development of depression, with evidence that peer and academic difficulties mediate predictions of later depression from ADHD. The present study hypothesized that parent-child relationship difficulties may be an additional potential mediator of this association. Academic, peer, and parent-child functioning were tested as mediators of the association of attention problems and depression in two distinctly different, yet complementary samples. Study 1 was a cross-sectional sample of 230 5–10 year-old children with and without ADHD. Study 2 was a prospective longitudinal sample of 472 youth followed prospectively from birth to age 20 at risk for depression. Despite differences in age, measures, and designs, both studies implicated peer and parent-child problems as unique mediators of depressive symptoms, although academic difficulties did not uniquely mediate the ADHD-depression association. Further, inattention symptoms, but not hyperactivity, predicted depressive symptoms via the disruption of interpersonal functioning. The inclusion of oppositional defiant disorder into models impacted results, and supported its independent role in parent-child problems. Implications include support for interventions that target interpersonal competence, which may effectively reduce the risk of depression among children with ADHD. PMID:24016021

Eating Problems and Their Risk Factors: A 7-Year Longitudinal Study of a Population Sample of Norwegian Adolescent Girls

Science.gov (United States)

Kansi, Juliska; Wichstrom, Lars; Bergman, Lars R.

2005-01-01

The longitudinal stability of eating problems and their relationships to risk factors were investigated in a representative population sample of 623 Norwegian girls aged 13-14 followed over 7 years (3 time points). Three eating problem symptoms were measured: Restriction, Bulimia-food preoccupation, and Diet, all taken from the 12-item Eating…

A Hybrid Tabu Search Algorithm for a Real-World Open Vehicle Routing Problem Involving Fuel Consumption Constraints

Directory of Open Access Journals (Sweden)

Yunyun Niu

2018-01-01

Full Text Available Outsourcing logistics operation to third-party logistics has attracted more attention in the past several years. However, very few papers analyzed fuel consumption model in the context of outsourcing logistics. This problem involves more complexity than traditional open vehicle routing problem (OVRP, because the calculation of fuel emissions depends on many factors, such as the speed of vehicles, the road angle, the total load, the engine friction, and the engine displacement. Our paper proposed a green open vehicle routing problem (GOVRP model with fuel consumption constraints for outsourcing logistics operations. Moreover, a hybrid tabu search algorithm was presented to deal with this problem. Experiments were conducted on instances based on realistic road data of Beijing, China, considering that outsourcing logistics plays an increasingly important role in China’s freight transportation. Open routes were compared with closed routes through statistical analysis of the cost components. Compared with closed routes, open routes reduce the total cost by 18.5% with the fuel emissions cost down by nearly 29.1% and the diver cost down by 13.8%. The effect of different vehicle types was also studied. Over all the 60- and 120-node instances, the mean total cost by using the light-duty vehicles is the lowest.

Mathematical learning disabilities and attention deficit and/or hyperactivity disorder: A study of the cognitive processes involved in arithmetic problem solving.

Science.gov (United States)

Iglesias-Sarmiento, Valentín; Deaño, Manuel; Alfonso, Sonia; Conde, Ángeles

2017-02-01

The purpose of this study was to examine the contribution of cognitive functioning to arithmetic problem solving and to explore the cognitive profiles of children with attention deficit and/or hyperactivity disorder (ADHD) and with mathematical learning disabilities (MLD). The sample was made up of a total of 90 students of 4th, 5th, and 6th grade organized in three: ADHD (n=30), MLD (n=30) and typically achieving control (TA; n=30) group. Assessment was conducted in two sessions in which the PASS processes and arithmetic problem solving were evaluated. The ADHD group's performance in planning and attention was worse than that of the control group. Children with MLD obtained poorer results than the control group in planning and simultaneous and successive processing. Executive processes predicted arithmetic problem solving in the ADHD group whereas simultaneous processing was the unique predictor in the MLD sample. Children with ADHD and with MLD showed characteristic cognitive profiles. Groups' problem-solving performance can be predicted from their cognitive functioning. Copyright © 2016 Elsevier Ltd. All rights reserved.

Active-involvement principle in dental health education

DEFF Research Database (Denmark)

Schou, L

1985-01-01

A basic problem in dental health education (DHE) is that the effect usually disappears shortly after the termination of a program. The purpose of the present study was to obtain long-term effect of a DHE-program by emphasizing the active involvement of the participants. The sample comprised...... an experimental and a control group, each of 68 unskilled workers, aged 18-64. Active participation was obtained by various means: Teaching was carried out in pre-existing peer groups, the participants' own goals and needs were included, the traditional dentist-patient barriers were excluded, the traditional...

Graphics for the multivariate two-sample problem

International Nuclear Information System (INIS)

Friedman, J.H.; Rafsky, L.C.

1981-01-01

Some graphical methods for comparing multivariate samples are presented. These methods are based on minimal spanning tree techniques developed for multivariate two-sample tests. The utility of these methods is illustrated through examples using both real and artificial data

Emergency preparedness: medical management of nuclear accidents involving large groups of victims

International Nuclear Information System (INIS)

Parmentier, N.; Nenot, J.C.

1988-01-01

The treatment of overexposed individuals implies hospitalisation in a specialized unit applying hematological intense care. If the accident results in a small number of casualties, the medical management does not raise major problems in most of the countries, where specialized units exist, as roughly 7% of the beds are available at any time. But an accident which would involved tens or hundreds of people raises much more problems for hospitalization. Such problems are also completely different and will involve steps in the medical handling, mainly triage, (combined injuries), determination of whole body dose levels, transient hospitalization. In this case, preplanning is necessary, adapted to the system of medical care in case of a catastrophic event in the given Country, with the main basic principles : emergency concerns essentially the classical injuries (burns and trauma) - and contamination problems in some cases - treatment of radiation syndrome is not an emergency during the first days but some essential actions have to be taken such as early blood sampling for biological dosimetry and for HLa typing

The method of varying amplitudes for solving (non)linear problems involving strong parametric excitation

DEFF Research Database (Denmark)

Sorokin, Vladislav; Thomsen, Jon Juel

2015-01-01

Parametrically excited systems appear in many fields of science and technology, intrinsically or imposed purposefully; e.g. spatially periodic structures represent an important class of such systems [4]. When the parametric excitation can be considered weak, classical asymptotic methods like...... the method of averaging [2] or multiple scales [6] can be applied. However, with many practically important applications this simplification is inadequate, e.g. with spatially periodic structures it restricts the possibility to affect their effective dynamic properties by a structural parameter modulation...... of considerable magnitude. Approximate methods based on Floquet theory [4] for analyzing problems involving parametric excitation, e.g. the classical Hill’s method of infinite determinants [3,4], can be employed also in cases of strong excitation; however, with Floquet theory being applicable only for linear...

Optimal time points sampling in pathway modelling.

Science.gov (United States)

Hu, Shiyan

2004-01-01

Modelling cellular dynamics based on experimental data is at the heart of system biology. Considerable progress has been made to dynamic pathway modelling as well as the related parameter estimation. However, few of them gives consideration for the issue of optimal sampling time selection for parameter estimation. Time course experiments in molecular biology rarely produce large and accurate data sets and the experiments involved are usually time consuming and expensive. Therefore, to approximate parameters for models with only few available sampling data is of significant practical value. For signal transduction, the sampling intervals are usually not evenly distributed and are based on heuristics. In the paper, we investigate an approach to guide the process of selecting time points in an optimal way to minimize the variance of parameter estimates. In the method, we first formulate the problem to a nonlinear constrained optimization problem by maximum likelihood estimation. We then modify and apply a quantum-inspired evolutionary algorithm, which combines the advantages of both quantum computing and evolutionary computing, to solve the optimization problem. The new algorithm does not suffer from the morass of selecting good initial values and being stuck into local optimum as usually accompanied with the conventional numerical optimization techniques. The simulation results indicate the soundness of the new method.

Sample problem manual for benchmarking of cask analysis codes

International Nuclear Information System (INIS)

Glass, R.E.

1988-02-01

A series of problems have been defined to evaluate structural and thermal codes. These problems were designed to simulate the hypothetical accident conditions given in Title 10 of the Code of Federal Regulation, Part 71 (10CFR71) while retaining simple geometries. This produced a problem set that exercises the ability of the codes to model pertinent physical phenomena without requiring extensive use of computer resources. The solutions that are presented are consensus solutions based on computer analyses done by both national laboratories and industry in the United States, United Kingdom, France, Italy, Sweden, and Japan. The intent of this manual is to provide code users with a set of standard structural and thermal problems and solutions which can be used to evaluate individual codes. 19 refs., 19 figs., 14 tabs

Using the bootstrap in a multivariadte data problem: An example

International Nuclear Information System (INIS)

Glosup, J.G.; Axelrod, M.C.

1995-01-01

The use of the bootstrap in the multivariate version of the paired t-test is considered and demonstrated through an example. The problem of interest involves comparing two different techniques for measuring the chemical constituents of an sample item. The bootstrap is used to form an empirical significance level for Hotelling's one-sample T-squared statistic. The bootstrap was selected to determine empirical significance levels because the implicit assumption of multivariate normality in the classic Hotelling's one-sample test night not hold. The results of both the classic and bootstrap test are presented and contrasted

Including Below Detection Limit Samples in Post Decommissioning Soil Sample Analyses

Energy Technology Data Exchange (ETDEWEB)

Kim, Jung Hwan; Yim, Man Sung [KAIST, Daejeon (Korea, Republic of)

2016-05-15

To meet the required standards the site owner has to show that the soil at the facility has been sufficiently cleaned up. To do this one must know the contamination of the soil at the site prior to clean up. This involves sampling that soil to identify the degree of contamination. However there is a technical difficulty in determining how much decontamination should be done. The problem arises when measured samples are below the detection limit. Regulatory guidelines for site reuse after decommissioning are commonly challenged because the majority of the activity in the soil at or below the limit of detection. Using additional statistical analyses of contaminated soil after decommissioning is expected to have the following advantages: a better and more reliable probabilistic exposure assessment, better economics (lower project costs) and improved communication with the public. This research will develop an approach that defines an acceptable method for demonstrating compliance of decommissioned NPP sites and validates that compliance. Soil samples from NPP often contain censored data. Conventional methods for dealing with censored data sets are statistically biased and limited in their usefulness.

Does parent-child agreement vary based on presenting problems? Results from a UK clinical sample.

Science.gov (United States)

Cleridou, Kalia; Patalay, Praveetha; Martin, Peter

2017-01-01

Discrepancies are often found between child and parent reports of child psychopathology, nevertheless the role of the child's presenting difficulties in relation to these is underexplored. This study investigates whether parent-child agreement on the conduct and emotional scales of the Strengths and Difficulties Questionnaire (SDQ) varied as a result of certain child characteristics, including the child's presenting problems to clinical services, age and gender. The UK-based sample consisted of 16,754 clinical records of children aged 11-17, the majority of which were female (57%) and White (76%). The dataset was provided by the Child Outcomes Research Consortium , which collects outcome measures from child services across the UK. Clinicians reported the child's presenting difficulties, and parents and children completed the SDQ. Using correlation analysis, the main findings indicated that agreement varied as a result of the child's difficulties for reports of conduct problems, and this seemed to be related to the presence or absence of externalising difficulties in the child's presentation. This was not the case for reports of emotional difficulties. In addition, agreement was higher when reporting problems not consistent with the child's presentation; for instance, agreement on conduct problems was greater for children presenting with internalising problems. Lastly, the children's age and gender did not seem to have an impact on agreement. These findings demonstrate that certain child presenting difficulties, and in particular conduct problems, may be related to informant agreement and need to be considered in clinical practice and research. Trial Registration This study was observational and as such did not require trial registration.

Use of decision trees to value investigation strategies for soil pollution problems

NARCIS (Netherlands)

Okx, J.P.; Stein, A.

2000-01-01

Remediation of a contaminated site usually requires costly actions, and several clean-up and sampling strategies may have to be compared by those involved in the decision-making process. In this paper several common environmental pollution problems have been addressed by using probabilistic decision

Standard practice for sampling special nuclear materials in multi-container lots

CERN Document Server

American Society for Testing and Materials. Philadelphia

1987-01-01

1.1 This practice provides an aid in designing a sampling and analysis plan for the purpose of minimizing random error in the measurement of the amount of nuclear material in a lot consisting of several containers. The problem addressed is the selection of the number of containers to be sampled, the number of samples to be taken from each sampled container, and the number of aliquot analyses to be performed on each sample. 1.2 This practice provides examples for application as well as the necessary development for understanding the statistics involved. The uniqueness of most situations does not allow presentation of step-by-step procedures for designing sampling plans. It is recommended that a statistician experienced in materials sampling be consulted when developing such plans. 1.3 The values stated in SI units are to be regarded as the standard. 1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standar...

Laser-induced breakdown spectroscopy for detection of heavy metals in environmental samples

Science.gov (United States)

Wisbrun, Richard W.; Schechter, Israel; Niessner, Reinhard; Schroeder, Hartmut

1993-03-01

The application of LIBS technology as a sensor for heavy metals in solid environmental samples has been studied. This specific application introduces some new problems in the LIBS analysis. Some of them are related to the particular distribution of contaminants in the grained samples. Other problems are related to mechanical properties of the samples and to general matrix effects, like the water and organic fibers content of the sample. An attempt has been made to optimize the experimental set-up for the various involved parameters. The understanding of these factors has enabled the adjustment of the technique to the substrates of interest. The special importance of the grain size and of the laser-induced aerosol production is pointed out. Calibration plots for the analysis of heavy metals in diverse sand and soil samples have been carried out. The detection limits are shown to be usually below the recent regulation restricted concentrations.

Compromise decision support problems for hierarchical design involving uncertainty

Science.gov (United States)

Vadde, S.; Allen, J. K.; Mistree, F.

1994-08-01

In this paper an extension to the traditional compromise Decision Support Problem (DSP) formulation is presented. Bayesian statistics is used in the formulation to model uncertainties associated with the information being used. In an earlier paper a compromise DSP that accounts for uncertainty using fuzzy set theory was introduced. The Bayesian Decision Support Problem is described in this paper. The method for hierarchical design is demonstrated by using this formulation to design a portal frame. The results are discussed and comparisons are made with those obtained using the fuzzy DSP. Finally, the efficacy of incorporating Bayesian statistics into the traditional compromise DSP formulation is discussed and some pending research issues are described. Our emphasis in this paper is on the method rather than the results per se.

The link between ethnicity, social disadvantage and mental health problems in a school-based multiethnic sample of children in the Netherlands

NARCIS (Netherlands)

Adriaanse, M.; Veling, W.; Doreleijers, T.A.H.; van Domburgh, L.

2014-01-01

To investigate to what extent differences in prevalence and types of mental health problems between ethnic minority and majority youth can be explained by social disadvantage. Mental health problems were assessed in a sample of 1,278 schoolchildren (55 % Dutch, 32 % Moroccan and 13 % Turkish; mean

The link between ethnicity, social disadvantage and mental health problems in a school-based multiethnic sample of children in the Netherlands

NARCIS (Netherlands)

Adriaanse, Marcia; Veling, Wim; Doreleijers, Theo; van Domburgh, Lieke

To investigate to what extent differences in prevalence and types of mental health problems between ethnic minority and majority youth can be explained by social disadvantage. Mental health problems were assessed in a sample of 1,278 schoolchildren (55 % Dutch, 32 % Moroccan and 13 % Turkish; mean

Random vs. systematic sampling from administrative databases involving human subjects.

Science.gov (United States)

Hagino, C; Lo, R J

1998-09-01

Two sampling techniques, simple random sampling (SRS) and systematic sampling (SS), were compared to determine whether they yield similar and accurate distributions for the following four factors: age, gender, geographic location and years in practice. Any point estimate within 7 yr or 7 percentage points of its reference standard (SRS or the entire data set, i.e., the target population) was considered "acceptably similar" to the reference standard. The sampling frame was from the entire membership database of the Canadian Chiropractic Association. The two sampling methods were tested using eight different sample sizes of n (50, 100, 150, 200, 250, 300, 500, 800). From the profile/characteristics, summaries of four known factors [gender, average age, number (%) of chiropractors in each province and years in practice], between- and within-methods chi 2 tests and unpaired t tests were performed to determine whether any of the differences [descriptively greater than 7% or 7 yr] were also statistically significant. The strengths of the agreements between the provincial distributions were quantified by calculating the percent agreements for each (provincial pairwise-comparison methods). Any percent agreement less than 70% was judged to be unacceptable. Our assessments of the two sampling methods (SRS and SS) for the different sample sizes tested suggest that SRS and SS yielded acceptably similar results. Both methods started to yield "correct" sample profiles at approximately the same sample size (n > 200). SS is not only convenient, it can be recommended for sampling from large databases in which the data are listed without any inherent order biases other than alphabetical listing by surname.

Perceived unmet need and barriers to care amongst street-involved people who use illicit drugs.

Science.gov (United States)

Hyshka, Elaine; Anderson, Jalene Tayler; Wild, T Cameron

2017-05-01

Research on perceived unmet need for care for mental health and substance use problems focuses on general populations to the detriment of hidden populations. This study describes prevalence and correlates of perceived unmet need for care in a community-based sample of street-involved people who use illicit drugs and identifies barriers to care. A sample of 320 street-involved people who use drugs participated in a structured, interviewer-assisted survey in Edmonton, Canada. The survey included the Perceived Need for Care Questionnaire, which assessed unmet need for care for mental health and substance use problems across seven service types. Logistic regression examined the associations between perceived unmet need, extent of socioeconomic marginalisation and problem severity. Barriers underlying unmet service needs were also examined. Most (82%) participants reported unmet need for one or more services during the past year. Odds of reporting one or more unmet needs were elevated amongst participants reporting substantial housing instability (adjusted odds ratio = 2.37; 95% confidence interval 1.19-4.28) and amongst participants meeting criteria for drug dependence (adjusted odds ratio = 1.22; 95% confidence interval 1.03-1.50), even after adjustment for sociodemographic covariates. Structural, rather than motivational barriers were the most commonly reported reasons underlying unmet service needs. Street-involved people who use drugs experience very high rates of perceived unmet need for care for mental health and substance use problems. General population studies on perceived unmet need are insufficient for understanding needs and barriers to care in hidden populations.[Hyshka E, Anderson JT, Wild TC. Perceived unmet need and barriers to care amongst street-involved people who use illicit drugs. Drug Alcohol Rev 2017;36:295-304]. © 2016 Australasian Professional Society on Alcohol and other Drugs.

The collection and field chemical analysis of water samples

International Nuclear Information System (INIS)

Korte, N.E.; Ealey, D.T.; Hollenbach, M.H.

1984-01-01

A successful water sampling program requires a clear understanding of appropriate measurement and sampling procedures in order to obtain reliable field data and representative samples. It is imperative that the personnel involved have a thorough knowledge of the limitations of the techniques being used. Though this seems self-evident, many sampling and field-chemical-analysis programs are still not properly conducted. Recognizing these problems, the Department of Energy contracted with Bendix Field Engineering Corporation through the Technical Measurements Center to develop and select procedures for water sampling and field chemical analysis at waste sites. The fundamental causese of poor field programs are addressed in this paper, largely through discussion of specific field-measurement techniques and their limitations. Recommendations for improvement, including quality-assurance measures, are also presented

Bonus algorithm for large scale stochastic nonlinear programming problems

CERN Document Server

Diwekar, Urmila

2015-01-01

This book presents the details of the BONUS algorithm and its real world applications in areas like sensor placement in large scale drinking water networks, sensor placement in advanced power systems, water management in power systems, and capacity expansion of energy systems. A generalized method for stochastic nonlinear programming based on a sampling based approach for uncertainty analysis and statistical reweighting to obtain probability information is demonstrated in this book. Stochastic optimization problems are difficult to solve since they involve dealing with optimization and uncertainty loops. There are two fundamental approaches used to solve such problems. The first being the decomposition techniques and the second method identifies problem specific structures and transforms the problem into a deterministic nonlinear programming problem. These techniques have significant limitations on either the objective function type or the underlying distributions for the uncertain variables. Moreover, these ...

Weighted piecewise LDA for solving the small sample size problem in face verification.

Science.gov (United States)

Kyperountas, Marios; Tefas, Anastasios; Pitas, Ioannis

2007-03-01

A novel algorithm that can be used to boost the performance of face-verification methods that utilize Fisher's criterion is presented and evaluated. The algorithm is applied to similarity, or matching error, data and provides a general solution for overcoming the "small sample size" (SSS) problem, where the lack of sufficient training samples causes improper estimation of a linear separation hyperplane between the classes. Two independent phases constitute the proposed method. Initially, a set of weighted piecewise discriminant hyperplanes are used in order to provide a more accurate discriminant decision than the one produced by the traditional linear discriminant analysis (LDA) methodology. The expected classification ability of this method is investigated throughout a series of simulations. The second phase defines proper combinations for person-specific similarity scores and describes an outlier removal process that further enhances the classification ability. The proposed technique has been tested on the M2VTS and XM2VTS frontal face databases. Experimental results indicate that the proposed framework greatly improves the face-verification performance.

Superposition Enhanced Nested Sampling

Directory of Open Access Journals (Sweden)

Stefano Martiniani

2014-08-01

Full Text Available The theoretical analysis of many problems in physics, astronomy, and applied mathematics requires an efficient numerical exploration of multimodal parameter spaces that exhibit broken ergodicity. Monte Carlo methods are widely used to deal with these classes of problems, but such simulations suffer from a ubiquitous sampling problem: The probability of sampling a particular state is proportional to its entropic weight. Devising an algorithm capable of sampling efficiently the full phase space is a long-standing problem. Here, we report a new hybrid method for the exploration of multimodal parameter spaces exhibiting broken ergodicity. Superposition enhanced nested sampling combines the strengths of global optimization with the unbiased or athermal sampling of nested sampling, greatly enhancing its efficiency with no additional parameters. We report extensive tests of this new approach for atomic clusters that are known to have energy landscapes for which conventional sampling schemes suffer from broken ergodicity. We also introduce a novel parallelization algorithm for nested sampling.

Choosing a suitable sample size in descriptive sampling

International Nuclear Information System (INIS)

Lee, Yong Kyun; Choi, Dong Hoon; Cha, Kyung Joon

2010-01-01

Descriptive sampling (DS) is an alternative to crude Monte Carlo sampling (CMCS) in finding solutions to structural reliability problems. It is known to be an effective sampling method in approximating the distribution of a random variable because it uses the deterministic selection of sample values and their random permutation,. However, because this method is difficult to apply to complex simulations, the sample size is occasionally determined without thorough consideration. Input sample variability may cause the sample size to change between runs, leading to poor simulation results. This paper proposes a numerical method for choosing a suitable sample size for use in DS. Using this method, one can estimate a more accurate probability of failure in a reliability problem while running a minimal number of simulations. The method is then applied to several examples and compared with CMCS and conventional DS to validate its usefulness and efficiency

TRAN-STAT, Issue No. 3, January 1978. Topics discussed: some statistical aspects of compositing field samples

International Nuclear Information System (INIS)

Gilbert, R.O.

1978-01-01

Some statistical aspects of compositing field samples of soils for determining the content of Pu are discussed. Some of the potential problems involved in pooling samples are reviewed. This is followed by more detailed discussions and examples of compositing designs, adequacy of mixing, statistical models and their role in compositing, and related topics

Gender and Direction of Effect of Alcohol Problems and Internalizing Symptoms in a Longitudinal Sample of College Students.

Science.gov (United States)

Homman, Lina E; Edwards, Alexis C; Cho, Seung Bin; Dick, Danielle M; Kendler, Kenneth S

2017-03-21

Alcohol problems and internalizing symptoms are consistently found to be associated but how they relate to each other is unclear. The present study aimed to address limitations in the literature of comorbidity of alcohol problems and internalizing symptoms by investigating the direction of effect between the phenotypes and possible gender differences in college students. We utilized data from a large longitudinal study of college students from the United States (N = 2607). Three waves of questionnaire-based data were collected over the first two years of college (in 2011-2013). Cross-lagged models were applied to examine the possible direction of effect of internalizing symptoms and alcohol problems. Possible effects of gender were investigated using multigroup modeling. There were significant correlations between alcohol problems and internalizing symptoms. A direction of effect was found between alcohol problems and internalizing symptoms but differed between genders. A unidirectional relationship varying with age was identified for males where alcohol problems initially predicted internalizing symptoms followed by internalizing symptoms predicting alcohol problems. For females, a unidirectional relationship existed wherein alcohol problems predicted internalizing symptoms. Conclusions/Importance: We conclude that the relationship between alcohol problems and internalizing symptoms is complex and differ between genders. In males, both phenotypes are predictive of each other, while in females the relationship is driven by alcohol problems. Importantly, our study examines a population-based sample, revealing that the observed relationships between alcohol problems and internalizing symptoms are not limited to individuals with clinically diagnosed mental health or substance use problems.

Data science in R a case studies approach to computational reasoning and problem solving

CERN Document Server

Nolan, Deborah

2015-01-01

Effectively Access, Transform, Manipulate, Visualize, and Reason about Data and ComputationData Science in R: A Case Studies Approach to Computational Reasoning and Problem Solving illustrates the details involved in solving real computational problems encountered in data analysis. It reveals the dynamic and iterative process by which data analysts approach a problem and reason about different ways of implementing solutions. The book's collection of projects, comprehensive sample solutions, and follow-up exercises encompass practical topics pertaining to data processing, including: Non-standar

Stability of Self-Reported Arousal to Sexual Fantasies Involving Children in a Clinical Sample of Pedophiles and Hebephiles.

Science.gov (United States)

Grundmann, Dorit; Krupp, Jurian; Scherner, Gerold; Amelung, Till; Beier, Klaus M

2016-07-01

In forensic research, there is a controversial discussion concerning the changeability or stability of pedophilia. Seto (2012) conceptualized pedophilia as a sexual age orientation characterized by an early onset, correlations with sexual and romantic behavior, and stability over time. However, empirical data are sparse and are mostly based on samples of detected offenders. The present study examined self-reported arousal to sexual fantasies involving children in a clinical sample of pedo-/hebephiles. In Study 1, retrospective self-reports on the age of onset and duration of sexual interest in minors were examined. In Study 2, the stability and variability of self-reported arousal to sexual fantasies involving children were evaluated prospectively. Non-prosecuted self-identifying pedo-/hebephilic men seeking professional help were recruited within the Berlin Prevention Project Dunkelfeld. Between 2005 and 2013, 494 participants completed the intake assessment. Self-reported data were collected via questionnaire focusing on sexual arousal to fantasies during masturbation involving prepubescent and/or early pubescent minors. Subsequent assessments of sexual arousal were obtained for 121 of the participants. The average time between the first and last assessment was approximately 29 months. Spearman's correlation coefficients examined the between-group rank-order and Wilcoxon signed-rank tests examined the within-individual mean-level stability. The majority of subjects reported an early onset of their pedo-/hebephilic sexual arousal. The rank-order stability was medium to high. Over the investigated period, the majority of subjects showed no or only minimal decrease or increase of self-reported sexual arousal. These results suggested that sexual arousal to fantasies involving prepubescent and/or early pubescent children is stable. Furthermore, the results support the conceptualization of pedo-/hebephilia as a sexual age orientation in men.

Associations between Polygenic Risk for Psychiatric Disorders and Substance Involvement

Directory of Open Access Journals (Sweden)

Caitlin E Carey

2016-08-01

Full Text Available Despite evidence of substantial comorbidity between psychiatric disorders and substance involvement, the extent to which common genetic factors contribute to their co-occurrence remains understudied. In the current study, we tested for associations between polygenic risk for psychiatric disorders and substance involvement (i.e., ranging from ever-use to severe dependence among 2573 non-Hispanic European-American participants from the Study of Addiction: Genetics and Environment. Polygenic risk scores (PRS for cross-disorder psychopathology (CROSS were generated based on the Psychiatric Genomics Consortium’s Cross-Disorder meta-analysis and then tested for associations with a factor representing general liability to alcohol, cannabis, cocaine, nicotine, and opioid involvement (GENSUB. Follow-up analyses evaluated specific associations between each of the 5 psychiatric disorders which comprised CROSS—attention deficit hyperactivity disorder (ADHD, autism spectrum disorder (AUT, bipolar disorder (BIP, major depressive disorder (MDD, and schizophrenia (SCZ—and involvement with each component substance included in GENSUB. CROSS PRS explained 1.10% of variance in GENSUB in our sample (p<0.001. After correction for multiple testing in our follow-up analyses of polygenic risk for each individual disorder predicting involvement with each component substance, associations remained between: A MDD PRS and non-problem cannabis use, B MDD PRS and severe cocaine dependence, C SCZ PRS and non-problem cannabis use and severe cannabis dependence, and D SCZ PRS and severe cocaine dependence. These results suggest that shared covariance from common genetic variation contributes to psychiatric and substance involvement comorbidity.

A separation theorem for the stochastic sampled-data LQG problem. [control of continuous linear plant disturbed by white noise

Science.gov (United States)

Halyo, N.; Caglayan, A. K.

1976-01-01

This paper considers the control of a continuous linear plant disturbed by white plant noise when the control is constrained to be a piecewise constant function of time; i.e. a stochastic sampled-data system. The cost function is the integral of quadratic error terms in the state and control, thus penalizing errors at every instant of time while the plant noise disturbs the system continuously. The problem is solved by reducing the constrained continuous problem to an unconstrained discrete one. It is shown that the separation principle for estimation and control still holds for this problem when the plant disturbance and measurement noise are Gaussian.

Near-optimal alternative generation using modified hit-and-run sampling for non-linear, non-convex problems

Science.gov (United States)

Rosenberg, D. E.; Alafifi, A.

2016-12-01

Water resources systems analysis often focuses on finding optimal solutions. Yet an optimal solution is optimal only for the modelled issues and managers often seek near-optimal alternatives that address un-modelled objectives, preferences, limits, uncertainties, and other issues. Early on, Modelling to Generate Alternatives (MGA) formalized near-optimal as the region comprising the original problem constraints plus a new constraint that allowed performance within a specified tolerance of the optimal objective function value. MGA identified a few maximally-different alternatives from the near-optimal region. Subsequent work applied Markov Chain Monte Carlo (MCMC) sampling to generate a larger number of alternatives that span the near-optimal region of linear problems or select portions for non-linear problems. We extend the MCMC Hit-And-Run method to generate alternatives that span the full extent of the near-optimal region for non-linear, non-convex problems. First, start at a feasible hit point within the near-optimal region, then run a random distance in a random direction to a new hit point. Next, repeat until generating the desired number of alternatives. The key step at each iterate is to run a random distance along the line in the specified direction to a new hit point. If linear equity constraints exist, we construct an orthogonal basis and use a null space transformation to confine hits and runs to a lower-dimensional space. Linear inequity constraints define the convex bounds on the line that runs through the current hit point in the specified direction. We then use slice sampling to identify a new hit point along the line within bounds defined by the non-linear inequity constraints. This technique is computationally efficient compared to prior near-optimal alternative generation techniques such MGA, MCMC Metropolis-Hastings, evolutionary, or firefly algorithms because search at each iteration is confined to the hit line, the algorithm can move in one

Self-Report Measures of Child and Adolescent Psychopathy as Predictors of Offending in Four Samples of Justice-Involved Youth

Science.gov (United States)

Boccaccini, Marcus T.; Epstein, Monica; Poythress, Norman; Douglas, Kevin S.; Campbell, Justin; Gardner, Gail; Falkenbach, Diana

2007-01-01

The authors examined the relation between self-report psychopathy measures and official records of offending in four samples of justice-involved youth (total N = 447). Psychopathy measures included the Antisocial Process Screening Device (APSD) and a modified version of the Childhood Psychopathy Scale (mCPS). Measures of offending included the…

Associations Between Bullying Involvement, Protective Factors, and Mental Health Among American Indian Youth.

Science.gov (United States)

Gloppen, Kari; McMorris, Barbara; Gower, Amy; Eisenberg, Marla

2017-08-17

Bullying involvement as a victim or perpetrator is associated with depression and suicidality, and American Indian (AI) youth experience a disproportionately high rate of these mental health issues. This study assessed whether AI young people involved in bullying were more likely to experience negative mental health problems than AI youth who were not involved in bullying, and identified protective factors that might support this particularly vulnerable population. Data come from 1,409 8th, 9th, and 11th Grade AI students who completed the 2013 Minnesota Student Survey. Logistic regression models estimated associations between bullying involvement and internalizing symptoms and suicidality. Selected protective factors (internal assets, empowerment, positive student-teacher relationships, and feeling safe at school) were also examined as independent variables. All forms of bullying perpetration and victimization were associated with increased risk for mental health problems (odds ratio [OR]: 1.57-2.87). AI youth who reported higher levels of protective factors were less likely to report internalizing symptoms and suicidality even in the presence of bullying involvement. For example, AI youth who reported high levels of internal assets had half the odds of reporting internalizing symptoms compared with those with low levels of internal assets (OR = 0.53, confidence interval [CI] 0.38, 0.74). Findings suggest that, similar to a general sample of students, bullying-involved AI students are significantly more likely to experience mental health problems. Promoting school as a safe place and incorporating culturally relevant programming to promote internal assets such as positive identity, social competence, and empowerment among AI students could help reduce the negative effects of bullying involvement. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Games and gambling involvement among casino patrons.

Science.gov (United States)

LaPlante, Debi A; Afifi, Tracie O; Shaffer, Howard J

2013-06-01

A growing literature is addressing the nature of the relationships among gambling activity, gambling involvement, and gambling-related problems. This research suggests that among the general population, compared to playing any specific game, gambling involvement is a better predictor of gambling-related problems. To date, researchers have not examined these relationships among casino patrons, a population that differs from the general population in a variety of important ways. A survey of 1160 casino patrons at two Las Vegas resort casinos allowed us to determine relationships between the games that patrons played during the 12 months before their casino visit, the games that patrons played during their casino visit, and patrons' self-perceived history of gambling-related problems. Results indicate that playing specific gambling games onsite predicted (i.e., statistically significant odds ratios ranging from .5 to 4.51) self-perceived gambling-related problems. However, after controlling for involvement, operationally defined as the number of games played during the current casino visit and self-reported gambling frequency during the past 12 months, the relationships between games and gambling-related problems disappeared or were attenuated (i.e., odds ratios no longer statistically significant). These results extend the burgeoning literature related to gambling involvement and its relationship to gambling-related problems.

ACTIVE AND PARTICIPATORY METHODS IN BIOLOGY: PROBLEM-SOLVING

Directory of Open Access Journals (Sweden)

Adela NEMEŞ

2010-01-01

Full Text Available We face with considerable challenge of developing students’ problem solving skills in our difficult environment. Good problem solving skills empower managers in their professional and personal lives. Problem solving skills are valued by academics and employers. The informations in Biology are often presented in abstract forms without contextualisation. Creative problem-solving process involves a few steps, which together provide a structured procedure for identifying challenges, generating ideas and implementing innovative solutions: identifying the problem, searching for possible solutions, selecting the most optimal solution and implementing a possible solution. Each aspect of personality has a different orientation to problem solving, different criteria for judging the effectiveness of the process and different associated strengths. Using real-world data in sample problems will also help facilitate the transfer process, since students can more easily identify with the context of a given situation. The paper describes the use of the Problem-Solving in Biology and the method of its administration. It also presents the results of a study undertaken to evaluate the value in teaching Biology. Problem-solving is seen as an essential skill that is developed in biology education.

Target problem (mis) matching: predictors and consequences of parent-youth agreement in a sample of anxious youth.

Science.gov (United States)

Hoffman, Lauren J; Chu, Brian C

2015-04-01

Parents and youth often report discrepant target problems upon seeking treatment for youth psychopathology, which can have important impact on therapy processes (e.g., dropout) and treatment outcomes, as entry-level attitudes have been found to be influential in ultimate use and benefit of treatment. The current study examined parent-youth agreement within an anxiety disordered sample by assessing demographic and diagnostic factors that may predict matching, as well as the impact of matching on attrition, treatment outcome, and parental satisfaction. Ninety-five youth with principal anxiety disorders received cognitive-behavioral treatment for anxiety at a university outpatient clinic. Youth and parents independently identified target problems during the pretreatment assessment. Target problems were coded into 25 qualitative categories representing diagnostic, symptom, and functional impairment domains, including diffuse anxiety, social anxiety, academic achievement, oppositional/behavior problems, sleep problems, suicidal ideation, and family functioning. The majority of parent-youth dyads (67.4%) agreed on at least one target problem. Although problems related to diffuse anxiety and social anxiety were reported most frequently, relatively low rates of agreement were found in these domains. Kappa values demonstrated higher levels of agreement for problems with specific fears, school attendance, and panic and lower levels of agreement for difficulties with worry, shame, and self-esteem. Further, youth diagnosed with comorbid externalizing disorders were less likely to agree with their parents on at least one target problem. No effects were found for gender, age, or number of diagnoses in predicting agreement. Target problem agreement did not significantly impact rates of attrition or diagnostic remission, but did predict some measures of parental satisfaction. Results suggest that disagreement on treatment goals exists even within a narrow treatment population and

Exact sampling of the unobserved covariates in Bayesian spline models for measurement error problems.

Science.gov (United States)

Bhadra, Anindya; Carroll, Raymond J

2016-07-01

In truncated polynomial spline or B-spline models where the covariates are measured with error, a fully Bayesian approach to model fitting requires the covariates and model parameters to be sampled at every Markov chain Monte Carlo iteration. Sampling the unobserved covariates poses a major computational problem and usually Gibbs sampling is not possible. This forces the practitioner to use a Metropolis-Hastings step which might suffer from unacceptable performance due to poor mixing and might require careful tuning. In this article we show for the cases of truncated polynomial spline or B-spline models of degree equal to one, the complete conditional distribution of the covariates measured with error is available explicitly as a mixture of double-truncated normals, thereby enabling a Gibbs sampling scheme. We demonstrate via a simulation study that our technique performs favorably in terms of computational efficiency and statistical performance. Our results indicate up to 62 and 54 % increase in mean integrated squared error efficiency when compared to existing alternatives while using truncated polynomial splines and B-splines respectively. Furthermore, there is evidence that the gain in efficiency increases with the measurement error variance, indicating the proposed method is a particularly valuable tool for challenging applications that present high measurement error. We conclude with a demonstration on a nutritional epidemiology data set from the NIH-AARP study and by pointing out some possible extensions of the current work.

Solving local problems through local involvement? Experiences from Danish Urban Regeneration

DEFF Research Database (Denmark)

Jensen, Jesper Ole

-down approaches or massive public subsidies, the public regeneration schemes from the last decade have increasingly emphasized the need for involving local actors in the urban regeneration e.g. through partnerships, network building, involvement and participation of local actors and institutions, and financially...... agenda, and what can be learned from the development so far. Although ‘local involvement’ is a commonly used term in various urban regeneration programs, it can have many different meanings and implications. Therefore, the paper will discuss local involvement in the urban regeneration based on four...

Global gradient estimates for divergence-type elliptic problems involving general nonlinear operators

Science.gov (United States)

Cho, Yumi

2018-05-01

We study nonlinear elliptic problems with nonstandard growth and ellipticity related to an N-function. We establish global Calderón-Zygmund estimates of the weak solutions in the framework of Orlicz spaces over bounded non-smooth domains. Moreover, we prove a global regularity result for asymptotically regular problems which are getting close to the regular problems considered, when the gradient variable goes to infinity.

Sample size methodology

CERN Document Server

Desu, M M

2012-01-01

One of the most important problems in designing an experiment or a survey is sample size determination and this book presents the currently available methodology. It includes both random sampling from standard probability distributions and from finite populations. Also discussed is sample size determination for estimating parameters in a Bayesian setting by considering the posterior distribution of the parameter and specifying the necessary requirements. The determination of the sample size is considered for ranking and selection problems as well as for the design of clinical trials. Appropria

When problem size matters: differential effects of brain stimulation on arithmetic problem solving and neural oscillations.

Directory of Open Access Journals (Sweden)

Bruno Rütsche

Full Text Available The problem size effect is a well-established finding in arithmetic problem solving and is characterized by worse performance in problems with larger compared to smaller operand size. Solving small and large arithmetic problems has also been shown to involve different cognitive processes and distinct electroencephalography (EEG oscillations over the left posterior parietal cortex (LPPC. In this study, we aimed to provide further evidence for these dissociations by using transcranial direct current stimulation (tDCS. Participants underwent anodal (30min, 1.5 mA, LPPC and sham tDCS. After the stimulation, we recorded their neural activity using EEG while the participants solved small and large arithmetic problems. We found that the tDCS effects on performance and oscillatory activity critically depended on the problem size. While anodal tDCS improved response latencies in large arithmetic problems, it decreased solution rates in small arithmetic problems. Likewise, the lower-alpha desynchronization in large problems increased, whereas the theta synchronization in small problems decreased. These findings reveal that the LPPC is differentially involved in solving small and large arithmetic problems and demonstrate that the effects of brain stimulation strikingly differ depending on the involved neuro-cognitive processes.

Calculation of sample problems related to two-phase flow blowdown transients in pressure relief piping of a PWR pressurizer

International Nuclear Information System (INIS)

Shin, Y.W.; Wiedermann, A.H.

1984-02-01

A method was published, based on the integral method of characteristics, by which the junction and boundary conditions needed in computation of a flow in a piping network can be accurately formulated. The method for the junction and boundary conditions formulation together with the two-step Lax-Wendroff scheme are used in a computer program; the program in turn, is used here in calculating sample problems related to the blowdown transient of a two-phase flow in the piping network downstream of a PWR pressurizer. Independent, nearly exact analytical solutions also are obtained for the sample problems. Comparison of the results obtained by the hybrid numerical technique with the analytical solutions showed generally good agreement. The good numerical accuracy shown by the results of our scheme suggest that the hybrid numerical technique is suitable for both benchmark and design calculations of PWR pressurizer blowdown transients

Syrlic: a Lagrangian code to handle industrial problems involving particles and droplets

International Nuclear Information System (INIS)

Peniguel, C.

1997-01-01

Numerous industrial applications require to solve droplets or solid particles trajectories and their effects on the flow. (fuel injection in combustion engine, agricultural spraying, spray drying, spray cooling, spray painting, particles separator, dispersion of pollutant, etc). SYRLIC is being developed to handle the dispersed phase while the continuous phase is tackled by classical Eulerian codes like N3S-EF, N3S-NATUR, ESTET. The trajectory of each droplet is calculated on unstructured grids or structured grids according the Eulerian code with SYRLIC is coupled. The forces applied to each particle are recalculated along each path. The Lagrangian approach treats the convection and the source terms exactly. It is particularly adapted to problems involving a wide range of particles characteristics (diameter, mass, etc). In the near future, wall interaction, heat transfer, evaporation more complex physics, etc, will be included. Turbulent effects will be accounted for by a Langevin equation. The illustration shows the trajectories followed by water droplets (diameter from 1 mm to 4 mm) in a cooling tower. the droplets are falling down due to gravity but are deflected towards the center of the tower because of a lateral wind. It is clear that particles are affected differently according their diameter. The Eulerian flow field used to compute the forces has been generated by N3S-AERO, on an unstructured mesh

Parent-Reported Psychological and Sleep Problems in a Preschool-Aged Community Sample: Prevalence of Sleep Problems in Children with and without Emotional/Behavioural Problems

OpenAIRE

Salater, Julie; Røhr, Marthe

2010-01-01

Objective : To examine (a) the prevalence of sleep problems among 4-year-olds in the general population, (b) the prevalence of sleep problems among children with emotional and/or behavioural problems, and (c) whether specific sleep problems are associated with particular emotional/behavioural problems. Method: Using The Preschool Age Psychiatric Assessment (PAPA) , data about sleep and emotional/behavioural problems was obtained from 727 parents of 4-year-olds, recruited for a large...

Boat sampling

International Nuclear Information System (INIS)

Citanovic, M.; Bezlaj, H.

1994-01-01

This presentation describes essential boat sampling activities: on site boat sampling process optimization and qualification; boat sampling of base material (beltline region); boat sampling of weld material (weld No. 4); problems accompanied with weld crown varieties, RPV shell inner radius tolerance, local corrosion pitting and water clarity. The equipment used for boat sampling is described too. 7 pictures

LEARNING PROBLEMS IN CHILDREN WITH MILD INTELLECTUAL DISABILITY

Directory of Open Access Journals (Sweden)

Keskinova Angelka

2018-04-01

Full Text Available School failure is one of the more complex, more difficult and unfortunately frequent problem that modern school meets. Many factors can cause school failure, such as: child development characteristics, family and school-originated factors. The purpose of the research is analysis of the specific learning problems in students with a mild intellectual disability. For our research we used ACADIA test, which contains 13 subtests for assessing the overall individual functioning. The research involved 144 students. We divided the sample into two groups, children with intellectual disability (our target group and control group. We found that generally all students with the intellectual disability have special learning problems. According to individual subtests analysis we concluded that the ability for visual association is best developed among these students while on the subtest for auditory memory they achieved worse results. With the analysis of the control group we found that 13.75% of the students have special learning problems.

Reentry challenges facing women with mental health problems.

Science.gov (United States)

Visher, Christy A; Bakken, Nicholas W

2014-01-01

Women entering the correctional system represent a population at high risk for mental health and the body of research on the mental health needs of women offenders is growing. These mental health problems pose challenges for women at every stage of the criminal justice process, from arrest to incarceration to community reentry and reintegration. In this article, we examined mental health status among a sample of 142 women leaving confinement and the role that mental health problems played in shaping their reentry outcomes using data collected between 2002 and 2005 in Houston, Texas. In the year after leaving prison, women with mental health problems reported poorer health, more hospitalizations, more suicidal thoughts, greater difficulties securing housing and employment, more involvement in criminal behavior, and less financial support from family than women with no indication of mental health problems. However, mental health status did not increase the likelihood of substance use relapse or reincarceration. The article concludes with a discussion of recommendations for improved policy and practice.

SELF-REPORTED DIFFERENCES BETWEEN CRASH-INVOLVED AND NON-CRASH-INVOLVED THREE-WHEELER DRIVERS IN SRI LANKA

Directory of Open Access Journals (Sweden)

A.K. SOMASUNDARASWARAN, Dr.

2006-01-01

Full Text Available Despite being an important mode of transportation in the developing world, little research has been conducted to understand the factors contributing to crashes involving three wheel vehicles. This study surveyed a convenient sample of 505 professional three-wheeler drivers in Sri Lanka to explore the similarities and differences in the demographic and work characteristics between three-wheeler drivers who reported experiencing at least one collision in the past twelve months and those who reported that they were not involved in any collisions. Our study revealed some interesting results that were quite different from those obtained in the studies on professional drivers in developed countries. In particular, both drivers with less than one year and more than five years of driving experience in our study were found to be associated with higher probability of crash involvement. Also, the number of trips per day and the average travel distance per trip were found to be insignificant in delineating between crash-involved and non-crash-involved drivers. Moreover, crash-involved drivers, on average, have significantly fewer working days per week and fewer hours per day, suggesting that the conventional approach used in most developed countries to tackle fatigue among professional drivers do not appear to be suitable for solving the road safety problem involving three-wheeler drivers in a developing country. Also, since the age of most drivers falls in a narrow range, this U-shaped relationship is not likely to be a result of youth and ageing but of inexperience in newer drivers and complacency in more experienced drivers. Lastly, since a relatively large proportion of the drivers had driven without a valid driving license, legislation and enforcement interventions are likely to be less effective than education and engineering countermeasures.

Study the Problem.

Science.gov (United States)

Choate, Joyce S.

1990-01-01

The initial step of a strategic process for solving mathematical problems, "studying the question," is discussed. A lesson plan for teaching students to identify and revise arithmetic problems is presented, involving directed instruction and supervised practice. (JDD)

Problems and risks involved in the projected storage of radioactive waste in a salt dome in the northwest of the FRG

International Nuclear Information System (INIS)

Mauthe, F.

1979-01-01

Current planning envisages long-term intermediate storage of radioactive waste and the exploration of the Gorleben salt dome by deep drilling in order to start appropriate mining work in case of favourable drilling results. The statements presented here on the problem of the 'Feasibility of ultimate storage of radioactive waste in salt deposits' (subject selected by the Government of the land Lower-Saxony) are aimed at informing the general public about the difficulties and problems involved in this waste disposal project and critically assess the arguments put forward by industry and licensing authorities in order to gain acceptance for this politically delicate project; the argumentation discussed here mainly refers to the field of geological science. (orig.) [de

Two Scales, Hybrid Model for Soils, Involving Artificial Neural Network and Finite Element Procedure

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Krasiński Marcin

2015-02-01

Full Text Available A hybrid ANN-FE solution is presented as a result of two level analysis of soils: a level of a laboratory sample and a level of engineering geotechnical problem. Engineering properties of soils (sands are represented directly in the form of ANN (this is in contrast with our former paper where ANN approximated constitutive relationships. Initially the ANN is trained with Duncan formula (Duncan and Chang [2], then it is re-trained (calibrated with some available experimental data, specific for the soil considered. The obtained approximation of the constitutive parameters is used directly in finite element method at the level of a single element at the scale of the laboratory sample to check the correct representation of the laboratory test. Then, the finite element that was successfully tested at the level of laboratory sample is used at the macro level to solve engineering problems involving the soil for which it was calibrated.

Father-involvement in a refugee sample: relations between posttraumatic stress and caregiving.

Science.gov (United States)

van Ee, Elisa; Sleijpen, Marieke; Kleber, Rolf J; Jongmans, Marian J

2013-12-01

Despite increased attention to the role of fathers within families, there is still a dearth of studies on the impact of trauma on father-involvement. This study investigates the quantity of father-involvement and the influence of posttraumatic stress on the quality of involvement in a refugee and asylum seeker population. Eighty refugees and asylum seekers and their young children (aged 18-42 months) were recruited. Measures included assessment of parental trauma (Harvard Trauma Questionnaire), quantity and quality of involvement (quantity of caregiving and Emotional Availability Scales), and perception of the father-child relationship (interview). The results show that fathers were less involved in caregiving tasks and play activities than mothers. No parental gender differences were found on each of the Emotional Availability Scales. Traumatic stress symptoms negatively affected the perception and the actual quality of parent-child interaction (sensitivity, structuring, nonhostility). Nevertheless, almost all fathers described their relationship with their child as good and their child as very important to them. As the quality of father-involvement is of importance to the development of the child, traumatized fathers are as much in need of clinical intervention as mothers. Despite the impact of posttraumatic stress, refugee fathers clearly are involved in the lives of their children. Mechanisms such as a deliberate withdrawal when stressed and compensation might enable affected fathers to step into the interaction when needed, raise the quality of involvement with their child, and diminish the negative impact of stress resulting from trauma and migration. © FPI, Inc.

Social Orientation: Problem Behavior and Motivations Toward Interpersonal Problem Solving Among High Risk Adolescents

Science.gov (United States)

Kuperminc, Gabriel P.; Allen, Joseph P.

2006-01-01

A model of problematic adolescent behavior that expands current theories of social skill deficits in delinquent behavior to consider both social skills and orientation toward the use of adaptive skills was examined in an ethnically and socioeconomically diverse sample of 113 male and female adolescents. Adolescents were selected on the basis of moderate to serious risk for difficulties in social adaptation in order to focus on the population of youth most likely to be targeted by prevention efforts. Structural equation modeling was used to examine cross-sectional data using multiple informants (adolescents, peers, and parents) and multiple methods (performance test and self-report). Adolescent social orientation, as reflected in perceived problem solving effectiveness, identification with adult prosocial values, and self-efficacy expectations, exhibited a direct association to delinquent behavior and an indirect association to drug involvement mediated by demonstrated success in using problem solving skills. Results suggest that the utility of social skill theories of adolescent problem behaviors for informing preventive and remedial interventions can be enhanced by expanding them to consider adolescents’ orientation toward using the skills they may already possess. PMID:16929380

Acceptance sampling using judgmental and randomly selected samples

Energy Technology Data Exchange (ETDEWEB)

Sego, Landon H.; Shulman, Stanley A.; Anderson, Kevin K.; Wilson, John E.; Pulsipher, Brent A.; Sieber, W. Karl

2010-09-01

We present a Bayesian model for acceptance sampling where the population consists of two groups, each with different levels of risk of containing unacceptable items. Expert opinion, or judgment, may be required to distinguish between the high and low-risk groups. Hence, high-risk items are likely to be identifed (and sampled) using expert judgment, while the remaining low-risk items are sampled randomly. We focus on the situation where all observed samples must be acceptable. Consequently, the objective of the statistical inference is to quantify the probability that a large percentage of the unsampled items in the population are also acceptable. We demonstrate that traditional (frequentist) acceptance sampling and simpler Bayesian formulations of the problem are essentially special cases of the proposed model. We explore the properties of the model in detail, and discuss the conditions necessary to ensure that required samples sizes are non-decreasing function of the population size. The method is applicable to a variety of acceptance sampling problems, and, in particular, to environmental sampling where the objective is to demonstrate the safety of reoccupying a remediated facility that has been contaminated with a lethal agent.

2nd International Workshop on Eigenvalue Problems : Algorithms, Software and Applications in Petascale Computing

CERN Document Server

Zhang, Shao-Liang; Imamura, Toshiyuki; Yamamoto, Yusaku; Kuramashi, Yoshinobu; Hoshi, Takeo

2017-01-01

This book provides state-of-the-art and interdisciplinary topics on solving matrix eigenvalue problems, particularly by using recent petascale and upcoming post-petascale supercomputers. It gathers selected topics presented at the International Workshops on Eigenvalue Problems: Algorithms; Software and Applications, in Petascale Computing (EPASA2014 and EPASA2015), which brought together leading researchers working on the numerical solution of matrix eigenvalue problems to discuss and exchange ideas – and in so doing helped to create a community for researchers in eigenvalue problems. The topics presented in the book, including novel numerical algorithms, high-performance implementation techniques, software developments and sample applications, will contribute to various fields that involve solving large-scale eigenvalue problems.

Fast Markov chain Monte Carlo sampling for sparse Bayesian inference in high-dimensional inverse problems using L1-type priors

International Nuclear Information System (INIS)

Lucka, Felix

2012-01-01

Sparsity has become a key concept for solving of high-dimensional inverse problems using variational regularization techniques. Recently, using similar sparsity-constraints in the Bayesian framework for inverse problems by encoding them in the prior distribution has attracted attention. Important questions about the relation between regularization theory and Bayesian inference still need to be addressed when using sparsity promoting inversion. A practical obstacle for these examinations is the lack of fast posterior sampling algorithms for sparse, high-dimensional Bayesian inversion. Accessing the full range of Bayesian inference methods requires being able to draw samples from the posterior probability distribution in a fast and efficient way. This is usually done using Markov chain Monte Carlo (MCMC) sampling algorithms. In this paper, we develop and examine a new implementation of a single component Gibbs MCMC sampler for sparse priors relying on L1-norms. We demonstrate that the efficiency of our Gibbs sampler increases when the level of sparsity or the dimension of the unknowns is increased. This property is contrary to the properties of the most commonly applied Metropolis–Hastings (MH) sampling schemes. We demonstrate that the efficiency of MH schemes for L1-type priors dramatically decreases when the level of sparsity or the dimension of the unknowns is increased. Practically, Bayesian inversion for L1-type priors using MH samplers is not feasible at all. As this is commonly believed to be an intrinsic feature of MCMC sampling, the performance of our Gibbs sampler also challenges common beliefs about the applicability of sample based Bayesian inference. (paper)

Few-body problem in celestial mechanics

Energy Technology Data Exchange (ETDEWEB)

Dermott, S F [Cornell Univ., Ithaca, NY (USA). Center for Radiophysics and Space Research

1984-03-26

The approaches taken by solar system dynamicists to various outstanding problems has changed considerably in recent years. Some problems for which few-body approaches have been tried in the past are now thought to involve collective phenomena. Observed features in Saturn's rings associated with resonances are examples. On the other hand, the problem of the origin of the Kirkwood gaps in the asteroid belt, for which a number of a many-body approaches (involving collisions or gas friction) have been tried, probably has a few-body solution and may involve chaos.

Enhancing the Effectiveness of Problem-Solving Processes through Employee Motivation and Involvement

Directory of Open Access Journals (Sweden)

Andrea Chlpeková

2014-12-01

indicators into the motivation system. The question to be answered is how to effectively use the intellectual capital of problem-solving teams and increase employees’ satisfaction in the broader context of the improvement of the effectiveness of problem-solving methodology.

Communication Problems in Turner Syndrome: A Sample Survey.

Science.gov (United States)

Van Borsel, John; Dhooge, Inge; Verhoye, Kristof; Derde, Kristel; Curfs, Leopold

1999-01-01

A survey of 128 females (ages 2-58) with Turner syndrome found almost one quarter were receiving or had received treatment for stuttering, articulation problems, and/or delayed language development, with the latter two disorders being checked most frequently. Only 4 or the 68 individuals receiving growth hormone treatment reported voice changes.…

[Cyber-bullying in adolescents: associated psychosocial problems and comparison with school bullying].

Science.gov (United States)

Kubiszewski, V; Fontaine, R; Huré, K; Rusch, E

2013-04-01

The aim of this study was to determine the prevalence of adolescents engaged in cyber-bullying and then to identify whether students involved in cyber- and school bullying present the same characteristics of internalizing problems (insomnia, perceived social disintegration, psychological distress) and externalizing problems (general aggressiveness, antisocial behavior). Semi-structured interviews were conducted with 738 adolescents from a high-school and a middle-school (mean age=14.8 ± 2.7). The Electronic Bullying Questionnaire and the Olweus Bully/Victim Questionnaire were used to identify profiles of cyber-bullying (cyber-victim, cyber-bully, cyber-bully/victim and cyber-neutral) and school bullying (victim, bully, bully/victim and neutral). Internalizing problems were investigated using the Athens Insomnia Scale, a Perceived Social Disintegration Scale and a Psychological Distress Scale. Externalizing problems were assessed using a General Aggressiveness Scale and an Antisocial Behavior Scale. Almost one student in four was involved in cyber-bullying (16.4% as cyber-victim, 4.9% as cyber-bully and 5.6% as cyber-bully/victim); 14% of our sample was engaged in school bullying as a victim, 7.2% as a bully and 2.8% as a bully/victim. The majority of adolescents involved in cyber-bullying were not involved in school bullying. With regard to the problems associated with school bullying, internalizing problems were more prevalent in victims and bully/victims, whereas externalizing problems were more common in bullies and bully/victims. A similar pattern was found in cyber-bullying where internalizing problems were characteristic of cyber-victims and cyber-bully/victims. Insomnia was elevated in the cyber-bully group which is specific to cyberbullying. General aggressiveness and antisocial behavior were more prevalent in cyber-bullies and cyber-bully/victims. Looking at the differences between types of bullying, victims of "school only" and "school and cyber

Neighborhood Qualification of the Association between Parenting and Problem Behavior Trajectories among Mexican-origin Father-Adolescent Dyads

OpenAIRE

White, Rebecca M. B.; Liu, Yu; Gonzales, Nancy A.; Knight, George P.; Tein, Jenn-Yun

2016-01-01

To address the combined importance of fathers and neighborhoods for adolescent adjustment, we examined whether associations between fathers' parenting and adolescents' problem behaviors were qualified by neighborhood adversity. We captured both mainstream (e.g., authoritative) and alternative (e.g., no-nonsense, reduced involvement) parenting styles and examined parenting and neighborhood effects on changes over time in problem behaviors among a sample of Mexican-origin father-adolescent dyad...

Health literacy, numeracy, and other characteristics associated with hospitalized patients' preferences for involvement in decision making.

Science.gov (United States)

Goggins, Kathryn M; Wallston, Kenneth A; Nwosu, Samuel; Schildcrout, Jonathan S; Castel, Liana; Kripalani, Sunil

2014-01-01

Little research has examined the association of health literacy and numeracy with patients' preferred involvement in the problem-solving and decision-making process in the hospital. Using a sample of 1,249 patients hospitalized with cardiovascular disease from the Vanderbilt Inpatient Cohort Study (VICS), we assessed patients' preferred level of involvement using responses to two scenarios of differing symptom severity from the Problem-Solving Decision-Making Scale. Using multivariable modeling, we determined the relationship of health literacy, subjective numeracy, and other patient characteristics with preferences for involvement in decisions, and how this differed by scenario. The authors found that patients with higher levels of health literacy desired more participation in the problem-solving and decision-making process, as did patients with higher subjective numeracy skills, greater educational attainment, female gender, less perceived social support, or greater health care system distrust (pparticipate more in the decision-making process when the hypothetical symptom they were experiencing was less severe (i.e., they deferred more to their physician when the hypothetical symptom was more severe). These findings underscore the role that patient characteristics, especially health literacy and numeracy, play in decisional preferences among hospitalized patients.

Already at the Table: Patterns of Play and Gambling Involvement Prior to Gambling Expansion.

Science.gov (United States)

Nelson, Sarah E; LaPlante, Debi A; Gray, Heather M; Tom, Matthew A; Kleschinsky, John H; Shaffer, Howard J

2018-03-01

During 2011, the Governor of Massachusetts signed a bill to allow casino gambling in the state (Commonwealth of Massachusetts 2011). As a result, two resort casinos will begin operations during 2018 and 2019; a smaller slots parlor began operations during June 2015. Prior to this expansion, gambling was widely available in Massachusetts, through the state lottery, off-track betting, and gambling opportunities available in neighboring states. Within this context, it is important to understand the patterns of gambling involvement in the population prior to gambling expansion. The current study examined gambling involvement, patterns of play, and gambling-related problems prior to gambling expansion among a sample of 511 Massachusetts residents who were members of a statewide Internet panel. To measure patterns of play, we asked questions about past-year games played and frequency of play. To measure breadth of involvement, we assessed the number of different games played. To measure depth of involvement, we measured time spent gambling, amount wagered, and amount won or lost. Principal component analysis revealed four play pattern components accounting for more than 50% of the variance in game play frequency. Multiple regression analyses revealed that component scores composed of casino gambling and skill-based gambling (e.g., poker, sports) variables uniquely contributed to the prediction of gambling-related problems, even when depth of involvement was controlled. However, the addition of breadth of involvement to the model resulted in a model where no set of variables contributed significantly, suggesting a complex relationship among play patterns, depth, and breadth of involvement. The study established discrete and distinguishable gambling play patterns associated with gambling-related problems and identified groups of individuals potentially vulnerable to the effects of gambling expansion.

Transactional effects among maternal depression, neighborhood deprivation, and child conduct problems from early childhood through adolescence: A tale of two low-income samples.

Science.gov (United States)

Shaw, Daniel S; Sitnick, Stephanie L; Reuben, Julia; Dishion, Thomas J; Wilson, Melvin N

2016-08-01

The current study sought to advance our understanding of transactional processes among maternal depression, neighborhood deprivation, and child conduct problems (CP) using two samples of low-income families assessed repeatedly from early childhood to early adolescence. After accounting for initial levels of negative parenting, independent and reciprocal effects between maternal depressive symptoms and child CP were evident across both samples, beginning in early childhood and continuing through middle childhood and adolescence. In addition, neighborhood effects were consistently found in both samples after children reached age 5, with earlier neighborhood effects on child CP and maternal depression found in the one exclusively urban sample of families with male children. The results confirm prior research on the independent contribution of maternal depression and child CP to the maintenance of both problem behaviors. The findings also have implications for designing preventative and clinical interventions to address child CP for families living in high-risk neighborhoods.

Mental health problems and their association to violence and maltreatment in a nationally representative sample of Tanzanian secondary school students.

Science.gov (United States)

Nkuba, Mabula; Hermenau, Katharin; Goessmann, Katharina; Hecker, Tobias

2018-04-12

Little is known about the prevalence of mental health problems among adolescents in Sub-Saharan Africa. Research consistently determined violence and maltreatment to be important risk factors. In this study, we examined the prevalence of mental health problems among adolescents in Tanzania, as well as the association with exposure to violence and maltreatment. We administered a set of questionnaires (e.g., strength and difficulties questionnaire; conflict tactic scale) to a nationally representative sample of 700 Tanzanian secondary school children (52% girls; age 14.92 years, SD = 1.02) and 333 parents or primary caregivers (53% females; age 43.47 years, SD = 9.02). 41% of the students reported an elevated level of mental health problems (emotional problems 40%, peer problems 63%, conduct problems 45%, hyperactivity 17%) in the past 6 months. Concordantly, 31% of parents reported observing an elevated level of mental health problems in their children (emotional problems 37%, peer problems 54%, conduct problems 35%, hyperactivity 17%). After controlling for other risk factors, we found significant associations between physical violence by parents and adolescent's mental health problems reported by students (β = 0.15) and their parents (β = 0.33). Our findings suggest a high prevalence of mental health problems using screening tools among secondary school students in Tanzania as well as an association between physical violence by parents and adolescents' mental health problems. Our findings emphasize the need to inform the population at large about the potentially adverse consequences associated with violence against children and adolescents.

Development, problem behavior, and quality of life in a population based sample of eight-year-old children with down syndrome

NARCIS (Netherlands)

Gameren-Oosterom, H.B.M. van; Fekkes, M.; Buitendijk, S.E.; Mohangoo, A.D.; Bruil, J.; Wouwe, J.P. van

2011-01-01

Objective: Children with Down syndrome (DS) have delayed psychomotor development. We investigated levels of development, problem behavior, and Health-Related Quality of Life (HRQoL) in a population sample of Dutch eight-year-old children with DS. Developmental outcomes were compared with normative

An Exploratory Study to Measure Excessive Involvement in Multitasking Interaction with Smart Devices.

Science.gov (United States)

Zhang, Yubo; Rau, Pei-Luen Patrick

2016-06-01

This study developed a scale measuring excessive involvement in multitasking interaction with smart devices. An online questionnaire was designed and surveyed in a sample of 380 respondents. The sample was split into two groups for exploratory and confirmatory factor analysis, respectively. A four-factor structure was identified with an acceptable goodness of fit. The first two factors, "Obsession and neglect" and "Problematic control," described the obsessive feelings, neglect behaviors, and behavior control problems accompanied by excessive multitasking interaction with smart devices. The latter two factors, "Multitasking preference" and "Polychronic orientation," referred to multitaskers' preference of engaging in multiple media use or interaction tasks rather than a single task from the time orientation perspective. The four-factor structure indicates that excessive involvement in multitasking interaction with smart devices shares some similarities with other behavioral addiction types, but demonstrates uniqueness compared with excessive engagement in single media use.

Early father's and mother's involvement and child's later educational outcomes.

Science.gov (United States)

Flouri, Eirini; Buchanan, Ann

2004-06-01

Few studies have investigated the individual long-term contributions that mothers and fathers make to their children's schooling. (1) To explore the role of early father involvement in children's later educational attainment independently of the role of early mother involvement and other confounds, (2) to investigate whether gender and family structure moderate the relationship between father's and mother's involvement and child's educational attainment, and (3) to explore whether the impact of father's involvement depends on the level of mother's involvement. The study used longitudinal data from the National Child Development Study. The initial sample were those 7,259 cohort members with valid data on mother involvement at age 7, father involvement at age 7, and school-leaving qualification by age 20. Of those, 3,303 were included in the final analysis. The measures were control variables, structural factors (family structure, sibship size and residential mobility), child factors (emotional/behavioural problems, cognitive ability and academic motivation), and father's and mother's involvement. Father involvement and mother involvement at age 7 independently predicted educational attainment by age 20. The association between parents' involvement and educational attainment was not stronger for sons than for daughters. Father involvement was not more important for educational attainment when mother involvement was low rather than high. Not growing up in intact two-parent family did not weaken the association between father's or mother's involvement and educational outcomes. Early father involvement can be another protective factor in counteracting risk conditions that might lead to later low attainment levels.

"Heart trouble" and religious involvement among older white men and women.

Science.gov (United States)

Thompson, Edward H; Killgore, Leslie; Connors, Heather

2009-09-01

Objective Few studies examine how older adults' health status affects spiritual and religious involvement. This study examined the effects of gender and poor cardiac health on older adults' ends, means, and quest religious motivations and frequency of private devotion. Method Longitudinal data (12 months between the T1 and T2 interviews) with 182 older adults sampled from a Northeast city were used to examine in a multivariate analysis of covariance whether gender and the existence of cardiac health problems at T1 affected older adults' spiritual and religious involvement at T2. Findings A gender and cardiac health condition interaction showed older men with heart trouble had more changes in religious involvement-they engaged in more religious doubt, prayed less, and were not as intrinsically oriented at T2. Discussion The findings strongly suggest that older men with heart trouble may maintain a masculine style and shun seeking divine help.

Who Involves Whom?

Science.gov (United States)

Ward, Clifford

1979-01-01

The author reviews the development of a parents' group at the Bradford Grange School (Manchester, United Kingdom) for ESN (educationally subnormal) children. Problems with the initial parents' group are pointed out, successful approaches are considered, and the importance of parent involvement is stressed. (SBH)

Factors Associated with Involvement in Bullying: A Study in Nicaragua

Directory of Open Access Journals (Sweden)

Eva M. Romera

2011-07-01

Full Text Available School bullying is one of the main problems affecting the quality of peer relationships in schools and in general the coexistence. At European level, there are scientific findings that indicate its nature, characteristics and factors related to its involvement. However, in poor and developing countries, where the problem is more serious, there is a high degree of awareness on this matter. The present study aimed to identify what factors may be influencing the occurrence of bullying in a representative sample of primary schools in the Nicaraguan capital. For this propose, 3042 students from Managua and its metropolitan area were explored with instruments comparable to those used in Europe. A multinomial logistic regression analysis indicated that being a boy, to show antisocial behaviors and attitudes and contact with drugs were the three factors most related with the role of aggressor, as well as negative relationships had a significant influence on involvement in this phenomenon, either as a victim, aggressor or victimized aggressor. Results are discussed in relation to the profiles of aggressor and victim of bullying in international studies focusing on differences in developed countries.

The relationships between father involvement and parental acceptance on the psychological adjustment of children and adolescents: The moderating effects of clinical status.

Science.gov (United States)

Rodríguez Ruiz, Mercedes; Holgado-Tello, Francisco Pablo; Carrasco, Miguel Ángel

2017-10-01

This study analyzes how a child's clinical condition modifies the relationship of father involvement, parental (fathers and mothers) acceptance and the child´s psychological adjustment, including the internalizing and externalizing problems. The cohort studied was composed of 226 subjects (61.94% males) with a mean age of 14.08 years, of which 113 children were from an incidental clinical sample and 113 from the general population. Both groups were matched by sex, age and family status, and the data show that the same structure of parent-child relationships that predict the child´s psychological adjustment can be accepted for both the clinical and non-clinical groups of children. However, the intensity of the relationships between the variables father involvement, parental acceptance and the child´s outcomes differed in function of the child's clinical status. Specifically, in the clinically-referred sample compared to non-clinical sample father involvement had a stronger effect on the children´s internalizing (but not the externalizing) problems and on their global psychological adjustment via their perceived maternal acceptance. The role of father involvement in the family relationships of clinical children is discussed. This study provides important evidence to support the need for enhanced paternal participation in the intervention programs for families. Copyright © 2017 Elsevier B.V. All rights reserved.

Challenging problems in algebra

CERN Document Server

Posamentier, Alfred S

1996-01-01

Over 300 unusual problems, ranging from easy to difficult, involving equations and inequalities, Diophantine equations, number theory, quadratic equations, logarithms, more. Detailed solutions, as well as brief answers, for all problems are provided.

Designing the organizational creativity based on job characteristics and job involvement among physical education units’ employees of Technology University

Directory of Open Access Journals (Sweden)

Seyed Hossein Alavi

2017-10-01

Full Text Available The aim of the present study was designing the organizational creativity based on job characteristics and job involvement among physical education employees of Technology University. The statistical population of the present study consisted of all employees, experts, and physical education units’ managers. The statistical samples were 389 people reduced to 338 employees after eliminating the incomplete and useless questionnaires. The research method of the present study was descriptive-correlative. Three questionnaires of job characteristics, job involvement, and organizational creativity were used to evaluate the research variables which were distributed and gathered among research samples after translation and comparison with research samples via face validity (views of 12 sport management experts and construct validity. The research results were analyzed by Partial Least Square (PLS and showed that the best predictor of job involvement among physical education units’ employees of Technology University was problem solving (ES= 0.41. However, the job characteristics of autonomy (0.26 and job feedback (.024 had more effects on employees’ creativity. Other results showed that managers reported lower scores of job characteristics and creativity than sport employees. According to research findings, in order to achieve creativity in the workplace within physical education units of Technology University, the managers should stimulate the autonomy and feedback characteristics. Of course, it should not be neglected that this mechanism would be facilitated by creating the problem solving in job.

Problem video game playing is related to emotional distress in adolescents.

Science.gov (United States)

Gonzálvez, María T; Espada, José P; Tejeiro, Ricardo

2017-06-28

Problem use of video games is an increasing risk behaviour. High exposure of adolescents to video games has been linked to a variety of disorders, but the relationship between problem video game playing and emotional welfare is unknown. The aim of the study is to analyse problem video game playing in a sample of adolescents and to determine whether there are differences between online and offline players, in addition to examining its relationship with anxiety and depressive symptomatology. A sample of adolescents (N = 380) completed self-reports measuring video game use and symptoms of anxiety and depression. We found that 7.4% of females and 30% of males can be considered as playing at problem levels. Online players were almost 12 times more likely to play at high frequency than offline players (χ2 (1, 267) = 72.72, p < .001, OR = 11.63, 95% CI [6.31, 21.43]). Males play more frequently, and play more online (χ2 (1, 267) = 50.85, p < .001, OR = 6.74, 95% CI [3.90, 11.64]), with a clear relationship between problem video game playing and anxiety (r = .24; p < .001). In females, there is a relationship between problem video game playing and depression (r = .19; p < .05). Our findings contribute to a better understanding of the psychological variables involved in problem video game playing. The implementation of strategies is suggested in order to prevent pathological gaming and associated problems.

The Contribution of Game Genre and other Use Patterns to Problem Video Game Play among Adult Video Gamers.

Science.gov (United States)

Elliott, Luther; Ream, Geoffrey; McGinsky, Elizabeth; Dunlap, Eloise

2012-12-01

AIMS: To assess the contribution of patterns of video game play, including game genre, involvement, and time spent gaming, to problem use symptomatology. DESIGN: Nationally representative survey. SETTING: Online. PARTICIPANTS: Large sample (n=3,380) of adult video gamers in the US. MEASUREMENTS: Problem video game play (PVGP) scale, video game genre typology, use patterns (gaming days in the past month and hours on days used), enjoyment, consumer involvement, and background variables. FINDINGS: Study confirms game genre's contribution to problem use as well as demographic variation in play patterns that underlie problem video game play vulnerability. CONCLUSIONS: Identification of a small group of game types positively correlated with problem use suggests new directions for research into the specific design elements and reward mechanics of "addictive" video games. Unique vulnerabilities to problem use among certain groups demonstrate the need for ongoing investigation of health disparities related to contextual dimensions of video game play.

The Contribution of Game Genre and other Use Patterns to Problem Video Game Play among Adult Video Gamers

Science.gov (United States)

Ream, Geoffrey; McGinsky, Elizabeth; Dunlap, Eloise

2012-01-01

Aims To assess the contribution of patterns of video game play, including game genre, involvement, and time spent gaming, to problem use symptomatology. Design Nationally representative survey. Setting Online. Participants Large sample (n=3,380) of adult video gamers in the US. Measurements Problem video game play (PVGP) scale, video game genre typology, use patterns (gaming days in the past month and hours on days used), enjoyment, consumer involvement, and background variables. Findings Study confirms game genre's contribution to problem use as well as demographic variation in play patterns that underlie problem video game play vulnerability. Conclusions Identification of a small group of game types positively correlated with problem use suggests new directions for research into the specific design elements and reward mechanics of “addictive” video games. Unique vulnerabilities to problem use among certain groups demonstrate the need for ongoing investigation of health disparities related to contextual dimensions of video game play. PMID:23284310

Recommended radiological air sampling and internal contamination control at nuclear power plants

International Nuclear Information System (INIS)

Rich, B.L.; Ritter, P.D.; Martz, D.E.

1984-01-01

It has long been recognized by the NRC Technical Staffs that estimating the quantity of radioactivity inhaled by an individual worker involved large uncertainties. General air samples usually produce concentrations lower than those in the workers Breathing Zone (BZ). NRC guides have recognized this problem by specifying air monitoring programs which sample the Breathing Zone or concentrations known to be higher than that actually inhaled. In addition the availability of suitable samplers to obtain BZ samples and the practicality of requiring their use was somewhat in question to the NRC technical staff. AN NRC development contract was issued to provide a detailed review of the technical aspects of the problems and recommendations for practical upgrade of federal guidance. This project accomplished a review of the nuclear industry experience and knowledge through a literature search, site visits to representative licensed facilities, telephone surveys of many others, laboratory testing of personal air samplers (lapel samplers) and aerosol diffusion experiments to verify key conclusions and assumptions

Involving young people with mental health problems in improving healthcare

OpenAIRE

Milnes, Linda; Kendal, Sarah

2017-01-01

Latif et al’s (2017) paper is a valuable addition to knowledge in this field. It highlights the need to improve the education of registered children’s nurses in the care of children and young people (CYP) with physical health problems related to self-harm.

Ensemble Sampling

OpenAIRE

Lu, Xiuyuan; Van Roy, Benjamin

2017-01-01

Thompson sampling has emerged as an effective heuristic for a broad range of online decision problems. In its basic form, the algorithm requires computing and sampling from a posterior distribution over models, which is tractable only for simple special cases. This paper develops ensemble sampling, which aims to approximate Thompson sampling while maintaining tractability even in the face of complex models such as neural networks. Ensemble sampling dramatically expands on the range of applica...

The Impact of Including Below Detection Limit Samples in Post Decommissioning Soil Sample Analyses

Energy Technology Data Exchange (ETDEWEB)

Kim, Jung Hwan; Yim, Man-Sung [KAIST, Daejeon (Korea, Republic of)

2016-10-15

To meet the required standards the site owner has to show that the soil at the facility has been sufficiently cleaned up. To do this one must know the contamination of the soil at the site prior to clean up. This involves sampling that soil to identify the degree of contamination. However there is a technical difficulty in determining how much decontamination should be done. The problem arises when measured samples are below the detection limit. Regulatory guidelines for site reuse after decommissioning are commonly challenged because the majority of the activity in the soil at or below the limit of detection. Using additional statistical analyses of contaminated soil after decommissioning is expected to have the following advantages: a better and more reliable probabilistic exposure assessment, better economics (lower project costs) and improved communication with the public. This research will develop an approach that defines an acceptable method for demonstrating compliance of decommissioned NPP sites and validates that compliance. Soil samples from NPP often contain censored data. Conventional methods for dealing with censored data sets are statistically biased and limited in their usefulness. In this research, additional methods are performed using real data from a monazite manufacturing factory.

Improved sample size determination for attributes and variables sampling

International Nuclear Information System (INIS)

Stirpe, D.; Picard, R.R.

1985-01-01

Earlier INMM papers have addressed the attributes/variables problem and, under conservative/limiting approximations, have reported analytical solutions for the attributes and variables sample sizes. Through computer simulation of this problem, we have calculated attributes and variables sample sizes as a function of falsification, measurement uncertainties, and required detection probability without using approximations. Using realistic assumptions for uncertainty parameters of measurement, the simulation results support the conclusions: (1) previously used conservative approximations can be expensive because they lead to larger sample sizes than needed; and (2) the optimal verification strategy, as well as the falsification strategy, are highly dependent on the underlying uncertainty parameters of the measurement instruments. 1 ref., 3 figs

Evaluation of the Problem Behavior Frequency Scale-Teacher Report Form for Assessing Behavior in a Sample of Urban Adolescents.

Science.gov (United States)

Farrell, Albert D; Goncy, Elizabeth A; Sullivan, Terri N; Thompson, Erin L

2018-02-01

This study evaluated the structure and validity of the Problem Behavior Frequency Scale-Teacher Report Form (PBFS-TR) for assessing students' frequency of specific forms of aggression and victimization, and positive behavior. Analyses were conducted on two waves of data from 727 students from two urban middle schools (Sample 1) who were rated by their teachers on the PBFS-TR and the Social Skills Improvement System (SSIS), and on data collected from 1,740 students from three urban middle schools (Sample 2) for whom data on both the teacher and student report version of the PBFS were obtained. Confirmatory factor analyses supported first-order factors representing 3 forms of aggression (physical, verbal, and relational), 3 forms of victimization (physical, verbal and relational), and 2 forms of positive behavior (prosocial behavior and effective nonviolent behavior), and higher-order factors representing aggression, victimization, and positive behavior. Strong measurement invariance was established over gender, grade, intervention condition, and time. Support for convergent validity was found based on correlations between corresponding scales on the PBFS-TR and teacher ratings on the SSIS in Sample 1. Significant correlations were also found between teacher ratings on the PBFS-TR and student ratings of their behavior on the Problem Behavior Frequency Scale-Adolescent Report (PBFS-AR) and a measure of nonviolent behavioral intentions in Sample 2. Overall the findings provided support for the PBFS-TR and suggested that teachers can provide useful data on students' aggressive and prosocial behavior and victimization experiences within the school setting. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Protective factors associated with fewer multiple problem behaviors among homeless/runaway youth.

Science.gov (United States)

Lightfoot, Marguerita; Stein, Judith A; Tevendale, Heather; Preston, Kathleen

2011-01-01

Although homeless youth exhibit numerous problem behaviors, protective factors that can be targeted and modified by prevention programs to decrease the likelihood of involvement in risky behaviors are less apparent. The current study tested a model of protective factors for multiple problem behavior in a sample of 474 homeless youth (42% girls; 83% minority) ages 12 to 24 years. Higher levels of problem solving and planning skills were strongly related to lower levels of multiple problem behaviors in homeless youth, suggesting both the positive impact of preexisting personal assets of these youth and important programmatic targets for further building their resilience and decreasing problem behaviors. Indirect relationships between the background factors of self-esteem and social support and multiple problem behaviors were significantly mediated through protective skills. The model suggests that helping youth enhance their skills in goal setting, decision making, and self-reliant coping could lessen a variety of problem behaviors commonly found among homeless youth.

STEALTH: a Lagrange explicit finite difference code for solids, structural, and thermohydraulic analysis. Volume 2: sample and verification problems. Computer code manual

International Nuclear Information System (INIS)

Hofmann, R.

1982-08-01

STEALTH sample and verification problems are presented to help users become familiar with STEALTH capabilities, input, and output. Problems are grouped into articles which are completely self-contained. The pagination in each article is A.n, where A is a unique alphabetic-character article identifier and n is a sequential page number which starts from 1 on the first page of text for each article. Articles concerning new capabilities will be added as they become available. STEALTH sample and verification calculations are divided into the following general categories: transient mechanical calculations dealing with solids; transient mechanical calculations dealing with fluids; transient thermal calculations dealing with solids; transient thermal calculations dealing with fluids; static and quasi-static calculations; and complex boundary interaction calculations

Sampling and examination methods used for TMI-2 samples

International Nuclear Information System (INIS)

Marley, A.W.; Akers, D.W.; McIsaac, C.V.

1988-01-01

The purpose of this paper is to summarize the sampling and examination techniques that were used in the collection and analysis of TMI-2 samples. Samples ranging from auxiliary building air to core debris were collected and analyzed. Handling of the larger samples and many of the smaller samples had to be done remotely and many standard laboratory analytical techniques were modified to accommodate the extremely high radiation fields associated with these samples. The TMI-2 samples presented unique problems with sampling and the laboratory analysis of prior molten fuel debris. 14 refs., 8 figs

Ear recognition from one sample per person.

Directory of Open Access Journals (Sweden)

Long Chen

Full Text Available Biometrics has the advantages of efficiency and convenience in identity authentication. As one of the most promising biometric-based methods, ear recognition has received broad attention and research. Previous studies have achieved remarkable performance with multiple samples per person (MSPP in the gallery. However, most conventional methods are insufficient when there is only one sample per person (OSPP available in the gallery. To solve the OSPP problem by maximizing the use of a single sample, this paper proposes a hybrid multi-keypoint descriptor sparse representation-based classification (MKD-SRC ear recognition approach based on 2D and 3D information. Because most 3D sensors capture 3D data accessorizing the corresponding 2D data, it is sensible to use both types of information. First, the ear region is extracted from the profile. Second, keypoints are detected and described for both the 2D texture image and 3D range image. Then, the hybrid MKD-SRC algorithm is used to complete the recognition with only OSPP in the gallery. Experimental results on a benchmark dataset have demonstrated the feasibility and effectiveness of the proposed method in resolving the OSPP problem. A Rank-one recognition rate of 96.4% is achieved for a gallery of 415 subjects, and the time involved in the computation is satisfactory compared to conventional methods.

Ear recognition from one sample per person.

Science.gov (United States)

Chen, Long; Mu, Zhichun; Zhang, Baoqing; Zhang, Yi

2015-01-01

Biometrics has the advantages of efficiency and convenience in identity authentication. As one of the most promising biometric-based methods, ear recognition has received broad attention and research. Previous studies have achieved remarkable performance with multiple samples per person (MSPP) in the gallery. However, most conventional methods are insufficient when there is only one sample per person (OSPP) available in the gallery. To solve the OSPP problem by maximizing the use of a single sample, this paper proposes a hybrid multi-keypoint descriptor sparse representation-based classification (MKD-SRC) ear recognition approach based on 2D and 3D information. Because most 3D sensors capture 3D data accessorizing the corresponding 2D data, it is sensible to use both types of information. First, the ear region is extracted from the profile. Second, keypoints are detected and described for both the 2D texture image and 3D range image. Then, the hybrid MKD-SRC algorithm is used to complete the recognition with only OSPP in the gallery. Experimental results on a benchmark dataset have demonstrated the feasibility and effectiveness of the proposed method in resolving the OSPP problem. A Rank-one recognition rate of 96.4% is achieved for a gallery of 415 subjects, and the time involved in the computation is satisfactory compared to conventional methods.

Mercury exposure of workers and health problems related with small-scale gold panning and extraction

International Nuclear Information System (INIS)

Khan, S.; Shah, M.T.; Din, I.U.; Rehman, S.

2012-01-01

This study was conducted to investigate mercury (Hg) exposure and health problems related to small-scale gold panning and extraction (GPE) in the northern Pakistan. Urine and blood samples of occupational and non-occupational persons were analyzed for total Hg, while blood's fractions including red blood cells and plasma were analyzed for total Hg and its inorganic and organic species. The concentrations of Hg in urine and blood samples were significantly (P<0.01) higher in occupational persons as compared to non-occupational and exceeded the permissible limits set by World Health Organization (WHO) and United State Environmental Protection Agency (US-EPA). Furthermore, the data indicated that numerous health problems were present in occupational persons involved in GPE. (author)

Childhood Reports of Food Neglect and Impulse Control Problems and Violence in Adulthood

Directory of Open Access Journals (Sweden)

Michael G. Vaughn

2016-03-01

Full Text Available Food insecurity and hunger during childhood are associated with an array of developmental problems in multiple domains, including impulse control problems and violence. Unfortunately, extant research is based primarily on small convenience samples and an epidemiological assessment of the hunger-violence link is lacking. The current study employed data from Wave 1 (2001–2002 and Wave 2 (2004–2005 of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC. The NESARC is a nationally representative sample of non-institutionalized U.S. residents aged 18 years and older. Participants who experienced frequent hunger during childhood had significantly greater impulsivity, worse self-control, and greater involvement in several forms of interpersonal violence. These effects were stronger among whites, Hispanics, and males. The findings support general theoretical models implicating impulse control problems as a key correlate of crime and violence and add another facet to the importance of ameliorating food neglect in the United States.

The Association between Parental Personality Patterns and Internalising and Externalising Behaviour Problems in Children and Adolescents

Science.gov (United States)

Bertino, Melanie D.; Connell, Gabrielle; Lewis, Andrew J.

2012-01-01

Background: This study investigated the relationship between parental personality patterns and internalising and externalising behaviour problems in a clinically referred sample of children (aged 4-8) and adolescents (aged 12-18). Methods: Data from families involved in two clinical trials in Victoria, Australia were analysed (n = 59). Families…

ANALYSIS OF THE TEACHERS’ INVOLVEMENT IN THE DISCUSSION OF THE APPLICATION OF THE FEDERAL STATE EDUCATIONAL STANDARDS VIA ONLINE RESOURCES

Directory of Open Access Journals (Sweden)

С Н Вачкова

2017-12-01

Full Text Available This article presents the research results of the teachers’ involvement extent in current problems emerging in educational activities. The paper discusses the concept of involvement, its functions and scientific approaches to its analysis; suggests the original definition and structure of this concept, describes the chosen methodology of its analysis, database research and the nature of the sample, analysis tools. The base of the present research was the Internet portal “Public expertise of normative documents in education”. There is a detailed description of quantitative results, the indicators of teachers’ participation in discussing problems of education in relation to normative educational documents of Federal state educational standards of primary, basic and secondary general education. The research results showed the indicators of teachers’ activity and the expressed problems in application the Federal state educational standards.

The problem involving OPMEs and the health plans contracts: outline and analysis of the issue

Directory of Open Access Journals (Sweden)

MARTINS, Paulo Roberto do Nascimento

2016-06-01

Full Text Available This paper has as its scope to introduce and analyze some of most polemic issues involving the indications of OPMEs within the health plans contracts. During the text, are exhibited normative elements related to this context, as well as some judicial decisions concerning this matter, aiming to defend, with reasonable grounds, that the indication of the patient’s doctor, when choosing prostheses and orthoses, cannot be taken as the unique nor necessarily the best opinion, given the existence of other interests, beyond the patient’s health, that are often in stake as well. At the end, it is explained that, in light of the currently existing regulation in Brazil, in the context of the supplementary health system, to the patient’s doctor is given the authority only to indicate the characteristics of the materials needed, leaving it to the health plans Operators the choice of the brand and the manufacturer. As long as the courts deny these rules, this serious problem will not be solved.

Validity and Reliability of the Problem Solving Inventory (PSI in a Nationwide Sample of Greek Educators

Directory of Open Access Journals (Sweden)

Ntina Kourmousi

2016-06-01

Full Text Available The Problem Solving Inventory (PSI is designed to measure adults’ perceptions of problem-solving ability. The presented study aimed to translate it and assess its reliability and validity in a nationwide sample of 3668 Greek educators. In order to evaluate internal consistency reliability, Cronbach’s alpha coefficient was used. The scale’s construct validity was examined by a confirmatory factor analysis (CFA and by investigating its correlation with the Internality, Powerful others and Chance Multidimensional Locus of Control Scale (IPC LOC Scale, the Rosenberg Self-Esteem Scale (RSES and demographic information. Internal consistency reliability was satisfactory with Cronbach’s alphas ranging from 0.79 to 0.91 for all PSI scales. CFA confirmed that the bi-level model fitted the data well. The root mean square error of approximation (RMSEA, the comparative fit index (CFI and the goodness of fit index (GFI values were 0.030, 0.97 and 0.96, respectively, further confirming the bi-level model and the three-factors construct of the PSI. Intercorrelations and correlation coefficients between the PSI, the IPC LOC Scale and the RSES were significant. Age, sex, and working experience differences were found. In conclusion, the Greek version of the PSI was found to have satisfactory psychometric properties and therefore, it can be used to evaluate Greek teachers’ perceptions of their problem-solving skills.

Multiobjective Optimization Involving Quadratic Functions

Directory of Open Access Journals (Sweden)

Oscar Brito Augusto

2014-01-01

Full Text Available Multiobjective optimization is nowadays a word of order in engineering projects. Although the idea involved is simple, the implementation of any procedure to solve a general problem is not an easy task. Evolutionary algorithms are widespread as a satisfactory technique to find a candidate set for the solution. Usually they supply a discrete picture of the Pareto front even if this front is continuous. In this paper we propose three methods for solving unconstrained multiobjective optimization problems involving quadratic functions. In the first, for biobjective optimization defined in the bidimensional space, a continuous Pareto set is found analytically. In the second, applicable to multiobjective optimization, a condition test is proposed to check if a point in the decision space is Pareto optimum or not and, in the third, with functions defined in n-dimensional space, a direct noniterative algorithm is proposed to find the Pareto set. Simple problems highlight the suitability of the proposed methods.

An evaluation of sampling methods and supporting techniques for tackling lead in drinking water in Aberta Province

Science.gov (United States)

A collaborative project commenced in August 2013 with the aim of demonstrating a range of techniques that can be used in tackling the problems of lead in drinking water. The main project was completed in March 2014, with supplementary sampling exercises in mid-2014. It involved t...

Associations between Polygenic Risk for Psychiatric Disorders and Substance Involvement.

Science.gov (United States)

Carey, Caitlin E; Agrawal, Arpana; Bucholz, Kathleen K; Hartz, Sarah M; Lynskey, Michael T; Nelson, Elliot C; Bierut, Laura J; Bogdan, Ryan

2016-01-01

Despite evidence of substantial comorbidity between psychiatric disorders and substance involvement, the extent to which common genetic factors contribute to their co-occurrence remains understudied. In the current study, we tested for associations between polygenic risk for psychiatric disorders and substance involvement (i.e., ranging from ever-use to severe dependence) among 2573 non-Hispanic European-American participants from the Study of Addiction: Genetics and Environment. Polygenic risk scores (PRS) for cross-disorder psychopathology (CROSS) were generated based on the Psychiatric Genomics Consortium's Cross-Disorder meta-analysis and then tested for associations with a factor representing general liability to alcohol, cannabis, cocaine, nicotine, and opioid involvement (GENSUB). Follow-up analyses evaluated specific associations between each of the five psychiatric disorders which comprised CROSS-attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (AUT), bipolar disorder (BIP), major depressive disorder (MDD), and schizophrenia (SCZ)-and involvement with each component substance included in GENSUB. CROSS PRS explained 1.10% of variance in GENSUB in our sample (p cannabis use, (B) MDD PRS and severe cocaine dependence, (C) SCZ PRS and non-problem cannabis use and severe cannabis dependence, and (D) SCZ PRS and severe cocaine dependence. These results suggest that shared covariance from common genetic variation contributes to psychiatric and substance involvement comorbidity.

Maintenance of stability in γ spectrometric system of low active and environmental samples - a practical experience

International Nuclear Information System (INIS)

Ravishankar, R.; Bandyopadhyay, T.; Sarkar, P.K.

2011-01-01

Particle Accelerators are becoming part of the society with more and more medical and Industrial types are added every year in addition to research type of accelerators. The outflow of materials to the public domain from such accelerator facilities need to checked carefully and must be released after ensuring the activities of such materials should not exceed the regulatory limits. Health Physics Unit, VECC is involved in analyzing food product samples, seized samples which are suspected to contain Uranium etc and other environmental samples in addition to analyzing radioactive materials evolved from Operational Health Physics work. Most of these analyses involve γ Spectrometric Systems of high efficiency and high resolution types. The efficacy of the analysis and results depends on various parameters of the spectrometric system. The electrical noise from the power supply system and other noises picked up, even in the range of a few milli volts range, have been found to affect the stability of the system. These effects may not be present initially during installation but may creep in due course due to various reasons including weather conditions, wear and tear etc. Unless these problems are attended in regular intervals, the stability of the spectrometric systems and hence the results of analysis of the low active and environmental samples, will not be satisfactory. The work describes the practical problems faced by Health Physics Unit, the methods employed in identifying the problems, the necessary remedial measures taken, the final outcome in the stability and the procedures framed in order to avoid in future. (author)

Problem solving using soft systems methodology.

Science.gov (United States)

Land, L

This article outlines a method of problem solving which considers holistic solutions to complex problems. Soft systems methodology allows people involved in the problem situation to have control over the decision-making process.

Sampling solution traces for the problem of sorting permutations by signed reversals

Science.gov (United States)

2012-01-01

Background Traditional algorithms to solve the problem of sorting by signed reversals output just one optimal solution while the space of all optimal solutions can be huge. A so-called trace represents a group of solutions which share the same set of reversals that must be applied to sort the original permutation following a partial ordering. By using traces, we therefore can represent the set of optimal solutions in a more compact way. Algorithms for enumerating the complete set of traces of solutions were developed. However, due to their exponential complexity, their practical use is limited to small permutations. A partial enumeration of traces is a sampling of the complete set of traces and can be an alternative for the study of distinct evolutionary scenarios of big permutations. Ideally, the sampling should be done uniformly from the space of all optimal solutions. This is however conjectured to be ♯P-complete. Results We propose and evaluate three algorithms for producing a sampling of the complete set of traces that instead can be shown in practice to preserve some of the characteristics of the space of all solutions. The first algorithm (RA) performs the construction of traces through a random selection of reversals on the list of optimal 1-sequences. The second algorithm (DFALT) consists in a slight modification of an algorithm that performs the complete enumeration of traces. Finally, the third algorithm (SWA) is based on a sliding window strategy to improve the enumeration of traces. All proposed algorithms were able to enumerate traces for permutations with up to 200 elements. Conclusions We analysed the distribution of the enumerated traces with respect to their height and average reversal length. Various works indicate that the reversal length can be an important aspect in genome rearrangements. The algorithms RA and SWA show a tendency to lose traces with high average reversal length. Such traces are however rare, and qualitatively our results

Problems on Divisibility of Binomial Coefficients

Science.gov (United States)

Osler, Thomas J.; Smoak, James

2004-01-01

Twelve unusual problems involving divisibility of the binomial coefficients are represented in this article. The problems are listed in "The Problems" section. All twelve problems have short solutions which are listed in "The Solutions" section. These problems could be assigned to students in any course in which the binomial theorem and Pascal's…

An Investigation of Eighth Grade Students' Problem Posing Skills (Turkey Sample)

Science.gov (United States)

Arikan, Elif Esra; Ünal, Hasan

2015-01-01

To pose a problem refers to the creative activity for mathematics education. The purpose of the study was to explore the eighth grade students' problem posing ability. Three learning domains such as requiring four operations, fractions and geometry were chosen for this reason. There were two classes which were coded as class A and class B. Class A…

Childhood risk factors for criminal justice involvement in a sample of homeless people with serious mental illness.

Science.gov (United States)

Desai, R A; Lam, J; Rosenheck, R A

2000-06-01

It has been suggested that criminal justice involvement among the homeless, particularly those with mental illness, is largely situational. The objective of this study was to assess, in a sample of homeless seriously mentally ill people, the prevalence of childhood conduct disorder behaviors as a risk factor for adult criminal activity as well as the extent and types of adult criminal justice contact. Data were taken from the national ACCESS program, which conducted extensive baseline interviews with 7,222 homeless seriously mentally ill adults. The interview assessed demographics, childhood risk factors for criminal activity such as conduct disorder behaviors, foster care, and parental abuse, as well as current illness severity and recent criminal justice contact. The 2-month arrest rate in this sample was much higher than national rates (11% compared with 1% annually in the general population). Although most arrests were for minor crimes (10.8%), there were also substantial rates of arrest for major (2.7%) and substance-related charges (2.0%). The prevalence of a history of conduct disorder behavior was also substantial (55% in male subjects, 40% in female subjects), and conduct disorder was a strong predictor of recent criminal justice involvement, even after controlling for other predictors of arrest (odds ratio = 1.76 for major crimes, 1.49 for minor crimes, and 1.98 for substance-related crimes). Recent literature has criticized a trend to criminalize homeless mentally ill persons for attempting to get needed food, shelter, or medical attention. However, these data indicate that at least some proportion of arrests in this population are of people who have been exhibiting antisocial behavior since early adolescence, and that early antisocial behavior is a strong predictor of all types of recent arrests in this population.

Laser sampling

International Nuclear Information System (INIS)

Gorbatenko, A A; Revina, E I

2015-01-01

The review is devoted to the major advances in laser sampling. The advantages and drawbacks of the technique are considered. Specific features of combinations of laser sampling with various instrumental analytical methods, primarily inductively coupled plasma mass spectrometry, are discussed. Examples of practical implementation of hybrid methods involving laser sampling as well as corresponding analytical characteristics are presented. The bibliography includes 78 references

The Meaning of Emotional Overinvolvement in Early Development: Prospective Relations with Child Behavior Problems

Science.gov (United States)

Khafi, Tamar Y.; Yates, Tuppett M.; Sher-Censor, Efrat

2015-01-01

Emotional Overinvolvement (EOI) in parents’ Five Minute Speech Samples (FMSS; Magaña-Amato, 1993) is thought to measure overconcern and enmeshment with one’s child. Although related to maladaptive outcomes in studies of adult children, FMSS-EOI evidences varied relations with behavior problems in studies with young children. These mixed findings may indicate that certain FMSS-EOI criteria reflect inappropriate and excessive involvement with adult children, but do not indicate maladaptive processes when parenting younger children. Thus, this study evaluated relations of each FMSS-EOI criterion with changes in child behavior problems from preschool to first grade in a community sample of 223 child-mother dyads (47.98% female; Mage_W1 = 49.08 months; 56.50% Hispanic/Latina). Maternal FMSS-EOI ratings were obtained at wave 1, and independent examiners rated child externalizing and internalizing behavior problems at wave 1 and two years later. Path analyses indicated that both the Self-Sacrifice/Overprotection (SSOP) and Statements of Attitude (SOAs) FMSS-EOI criteria predicted increased externalizing problems. In contrast, Excessive Detail and Exaggerated Praise were not related to child externalizing behavior problems, and Emotional Display was not evident in this sample. None of the FMSS-EOI criteria evidenced significant relations with internalizing behavior problems. Multigroup comparisons indicated that the effect of SOAs on externalizing behavior problems was significant for boys but not for girls, and there were no significant group differences by race/ethnicity. These findings point to the salience of SSOP and SOAs for understanding the developmental significance of EOI in early development. PMID:26147935

The Effect of Learning Environments Based on Problem Solving on Students' Achievements of Problem Solving

Science.gov (United States)

Karatas, Ilhan; Baki, Adnan

2013-01-01

Problem solving is recognized as an important life skill involving a range of processes including analyzing, interpreting, reasoning, predicting, evaluating and reflecting. For that reason educating students as efficient problem solvers is an important role of mathematics education. Problem solving skill is the centre of mathematics curriculum.…

The concerned significant others of people with gambling problems in a national representative sample in Sweden - a 1 year follow-up study.

Science.gov (United States)

Svensson, Jessika; Romild, Ulla; Shepherdson, Emma

2013-11-21

Research into the impact of problem gambling on close social networks is scarce with the majority of studies only including help-seeking populations. To date only one study has examined concerned significant others (CSOs) from an epidemiological perspective and it did not consider gender. The aim of this study is to examine the health, social support, and financial situations of CSOs in a Swedish representative sample and to examine gender differences. A population study was conducted in Sweden in 2008/09 (n = 15,000, response rate 63%). Respondents were defined as CSOs if they reported that someone close to them currently or previously had problems with gambling. The group of CSOs was further examined in a 1-year follow up (weighted response rate 74% from the 8,165 respondents in the original sample). Comparisons were also made between those defined as CSOs only at baseline (47.7%, n = 554) and those defined as CSOs at both time points. In total, 18.2% of the population were considered CSOs, with no difference between women and men. Male and female CSOs experienced, to a large extent, similar problems including poor mental health, risky alcohol consumption, economic hardship, and arguments with those closest to them. Female CSOs reported less social support than other women and male CSOs had more legal problems and were more afraid of losing their jobs than other men. One year on, several problems remained even if some improvements were found. Both male and female CSOs reported more negative life events in the 1 year follow-up. Although some relationships are unknown, including between the CSOs and the individuals with gambling problems and the causal relationships between being a CSO and the range of associated problems, the results of this study indicate that gambling problems not only affect the gambling individual and their immediate close family but also the wider social network. A large proportion of the population can be defined as a CSO, half of whom are

Macau parents' perceptions of underage children's gambling involvement.

Science.gov (United States)

So, Ernest Moon Tong; Lao, Yorky Mei Po; Wong, Irene Lai Kuen

2017-01-01

The study examined Macau parents' perceptions of underage children's gambling involvement, and parents' attitudes towards help seeking if their children had a gambling problem. The parents' gambling behavior in the past year was also investigated. This is a parent survey using a self-administered questionnaire. A convenience sample of 311 Macau parents (106 fathers and 205 mothers) with underage children aged 3-17 years was recruited. The response rate is 77.8%. The participants were asked if they had ever approved or taught their underage children to gamble, and how did they award their children when they won in gambling games. The parents were also asked if they had gambled in the previous 12 months, and their gambling behavior was assessed by the Chinese Problem Gambling Severity Index (CPGSI). Half of the parents surveyed (52%) did not approve underage gambling but 81% taught their underage children to play different gambling games. Children were awarded with money (55%), praises (17.5%), toys (15%) and food (12.5%) when they won in games. One-fifth (20.6%) were distressed with their children's gambling problem. Many (68.8%) were willing to seek help to cope with children's gambling problems. Only 21.2% (n = 66) of the parents reported gambling in the past year. Using the CPGSI, 4.5% of these gamblers could be identified as problem gamblers, and 16.7% were moderate-risk gamblers. The study results indicate parent education should be included in prevention of underage gambling.

SOLUTION OF A MULTIVARIATE STRATIFIED SAMPLING PROBLEM THROUGH CHEBYSHEV GOAL PROGRAMMING

Directory of Open Access Journals (Sweden)

Mohd. Vaseem Ismail

2010-12-01

Full Text Available In this paper, we consider the problem of minimizing the variances for the various characters with fixed (given budget. Each convex objective function is first linearised at its minimal point where it meets the linear cost constraint. The resulting multiobjective linear programming problem is then solved by Chebyshev goal programming. A numerical example is given to illustrate the procedure.

Prevalence and correlates of bullying victimisation and perpetration in a nationally representative sample of Australian youth.

Science.gov (United States)

Thomas, Hannah J; Connor, Jason P; Lawrence, David M; Hafekost, Jennifer M; Zubrick, Stephen R; Scott, James G

2017-09-01

Bullying prevalence studies are limited by varied measurement methods and a lack of representative samples. This study estimated the national prevalence of bullying victimisation, perpetration and combined victim-perpetration experiences in a representative population-based sample of Australian youth. The relationships between the three types of bullying involvement with a range of mental health symptoms and diagnoses were also examined. A randomly selected nationally representative sample aged 11-17 years ( N = 2967, M age = 14.6 years; 51.6% male) completed the youth component of the Second Australian Child and Adolescent Survey of Mental Health and Wellbeing (Young Minds Matter). Parents or carers also completed a structured face-to-face interview that asked questions about a single randomly selected child in the household. The youth survey comprised self-reported bullying victimisation and perpetration (Olweus Bully-Victim Questionnaire-adapted), psychological distress (K10), emotional and behavioural problems (Strengths and Difficulties Questionnaire), as well as self-harm, suicide attempts and substance use. Modules from the Diagnostic Interview Schedule for Children Version IV were administered to all youth and parents to assess for mental disorder diagnoses (major depressive disorder, any anxiety disorder and any externalising disorder [attention-deficit hyperactivity disorder, oppositional defiant disorder and conduct disorder]). The 12-month prevalence of bullying victimisation was 13.3%, perpetration 1.6% and victim-perpetration 1.9%. Logistic regression models showed all forms of involvement in bullying were associated with increased risk of psychological distress, emotional and behavioural problems, substance use, self-harm and attempted suicide. Victimisation and victim-perpetration were associated with youth-reported major depressive disorder. There were also significant associations between bullying involvement and parent-reported diagnoses of major

Writing and mathematical problem solving in Grade 3

Directory of Open Access Journals (Sweden)

Belinda Petersen

2017-06-01

Full Text Available This article looks at writing tasks as a methodology to support learners’ mathematical problemsolving strategies in the South African Foundation Phase context. It is a qualitative case study and explores the relation between the use of writing in mathematics and development of learners’ problem-solving strategies and conceptual understanding. The research was conducted in a suburban Foundation Phase school in Cape Town with a class of Grade 3 learners involved in a writing and mathematics intervention. Writing tasks were modelled to learners and implemented by them while they were engaged in mathematical problem solving. Data were gathered from a sample of eight learners of different abilities and included written work, interviews, field notes and audio recordings of ability group discussions. The results revealed an improvement in the strategies and explanations learners used when solving mathematical problems compared to before the writing tasks were implemented. Learners were able to reflect critically on their thinking through their written strategies and explanations. The writing tasks appeared to support learners in providing opportunities to construct and apply mathematical knowledge and skills in their development of problem-solving strategies.

[The methodology and sample description of the National Survey on Addiction Problems in Hungary 2015 (NSAPH 2015)].

Science.gov (United States)

Paksi, Borbala; Demetrovics, Zsolt; Magi, Anna; Felvinczi, Katalin

2017-06-01

This paper introduces the methods and methodological findings of the National Survey on Addiction Problems in Hungary (NSAPH 2015). Use patterns of smoking, alcohol use and other psychoactive substances were measured as well as that of certain behavioural addictions (problematic gambling - PGSI, DSM-V, eating disorders - SCOFF, problematic internet use - PIUQ, problematic on-line gaming - POGO, problematic social media use - FAS, exercise addictions - EAI-HU, work addiction - BWAS, compulsive buying - CBS). The paper describes the applied measurement techniques, sample selection, recruitment of respondents and the data collection strategy as well. Methodological results of the survey including reliability and validity of the measures are reported. The NSAPH 2015 research was carried out on a nationally representative sample of the Hungarian adult population aged 16-64 yrs (gross sample 2477, net sample 2274 persons) with the age group of 18-34 being overrepresented. Statistical analysis of the weight-distribution suggests that weighting did not create any artificial distortion in the database leaving the representativeness of the sample unaffected. The size of the weighted sample of the 18-64 years old adult population is 1490 persons. The extent of the theoretical margin of error in the weighted sample is ±2,5%, at a reliability level of 95% which is in line with the original data collection plans. Based on the analysis of reliability and the extent of errors beyond sampling within the context of the database we conclude that inconsistencies create relatively minor distortions in cumulative prevalence rates; consequently the database makes possible the reliable estimation of risk factors related to different substance use behaviours. The reliability indexes of measurements used for prevalence estimates of behavioural addictions proved to be appropriate, though the psychometric features in some cases suggest the presence of redundant items. The comparison of

On Wasserstein Two-Sample Testing and Related Families of Nonparametric Tests

Directory of Open Access Journals (Sweden)

Aaditya Ramdas

2017-01-01

Full Text Available Nonparametric two-sample or homogeneity testing is a decision theoretic problem that involves identifying differences between two random variables without making parametric assumptions about their underlying distributions. The literature is old and rich, with a wide variety of statistics having being designed and analyzed, both for the unidimensional and the multivariate setting. Inthisshortsurvey,wefocusonteststatisticsthatinvolvetheWassersteindistance. Usingan entropic smoothing of the Wasserstein distance, we connect these to very different tests including multivariate methods involving energy statistics and kernel based maximum mean discrepancy and univariate methods like the Kolmogorov–Smirnov test, probability or quantile (PP/QQ plots and receiver operating characteristic or ordinal dominance (ROC/ODC curves. Some observations are implicit in the literature, while others seem to have not been noticed thus far. Given nonparametric two-sample testing’s classical and continued importance, we aim to provide useful connections for theorists and practitioners familiar with one subset of methods but not others.

Maternal Attachment Status, Mother-Child Emotion Talk, Emotion Understanding, and Child Conduct Problems

Directory of Open Access Journals (Sweden)

Brad M. Farrant

2013-01-01

Full Text Available Conduct problems that emerge in childhood often persist into adolescence and are associated with a range of negative outcomes. It is therefore important to identify the factors that predict conduct problems in early childhood. The present study investigated the relations among maternal attachment status, mother-child emotion talk, child emotion understanding, and conduct problems in a sample of 92 (46 males typically developing children (M age = 61.3 months, SD = 8.3 months. The results support a model in which maternal attachment status predicts the level of appropriate/responsive mother-child emotion talk, which predicts child emotion understanding, which in turn negatively predicts child conduct problems. These findings further underline the developmental role of mother-child emotion talk as well as the importance of involving parents in programs designed to increase children’s emotion understanding and/or decrease the incidence of conduct problems.

Active Involvement of Software Developers in Usability Engineering

DEFF Research Database (Denmark)

Bornoe, Nis; Stage, Jan

2017-01-01

The essence of usability evaluations is to produce feedback that supports the downstream utility so the interaction design can be improved and problems can be fixed. In practice, software development organizations experience several obstacles for conducting usability engineering. One suggested...... approach is to train and involve developers in all phases of usability activities from evaluations, to problem reporting, and making redesign proposals. Only limited work has previously investigated the impact of actively involving developers in usability engineering. In this paper, we present two small......, and problem fixing. At the organizational level, we found that the attitude towards and understanding of the role of usability engineering improved....

Moonrise: Sampling the South Pole-Aitken Basin to Address Problems of Solar System Significance

Science.gov (United States)

Zeigler, R. A.; Jolliff, B. L.; Korotev, R. L.; Shearer, C. K.

2016-01-01

A mission to land in the giant South Pole-Aitken (SPA) Basin on the Moon's southern farside and return a sample to Earth for analysis is a high priority for Solar System Science. Such a sample would be used to determine the age of the SPA impact; the chronology of the basin, including the ages of basins and large impacts within SPA, with implications for early Solar System dynamics and the magmatic history of the Moon; the age and composition of volcanic rocks within SPA; the origin of the thorium signature of SPA with implications for the origin of exposed materials and thermal evolution of the Moon; and possibly the magnetization that forms a strong anomaly especially evident in the northern parts of the SPA basin. It is well known from studies of the Apollo regolith that rock fragments found in the regolith form a representative collection of many different rock types delivered to the site by the impact process (Fig. 1). Such samples are well documented to contain a broad suite of materials that reflect both the local major rock formations, as well as some exotic materials from far distant sources. Within the SPA basin, modeling of the impact ejection process indicates that regolith would be dominated by SPA substrate, formed at the time of the SPA basin-forming impact and for the most part moved around by subsequent impacts. Consistent with GRAIL data, the SPA impact likely formed a vast melt body tens of km thick that took perhaps several million years to cool, but that nonetheless represents barely an instant in geologic time that should be readily apparent through integrated geochronologic studies involving multiple chronometers. It is anticipated that a statistically significant number of age determinations would yield not only the age of SPA but also the age of several prominent nearby basins and large craters within SPA. This chronology would provide a contrast to the Imbrium-dominated chronology of the nearside Apollo samples and an independent test of

Stochastic global optimization as a filtering problem

International Nuclear Information System (INIS)

Stinis, Panos

2012-01-01

We present a reformulation of stochastic global optimization as a filtering problem. The motivation behind this reformulation comes from the fact that for many optimization problems we cannot evaluate exactly the objective function to be optimized. Similarly, we may not be able to evaluate exactly the functions involved in iterative optimization algorithms. For example, we may only have access to noisy measurements of the functions or statistical estimates provided through Monte Carlo sampling. This makes iterative optimization algorithms behave like stochastic maps. Naive global optimization amounts to evolving a collection of realizations of this stochastic map and picking the realization with the best properties. This motivates the use of filtering techniques to allow focusing on realizations that are more promising than others. In particular, we present a filtering reformulation of global optimization in terms of a special case of sequential importance sampling methods called particle filters. The increasing popularity of particle filters is based on the simplicity of their implementation and their flexibility. We utilize the flexibility of particle filters to construct a stochastic global optimization algorithm which can converge to the optimal solution appreciably faster than naive global optimization. Several examples of parametric exponential density estimation are provided to demonstrate the efficiency of the approach.

Continuous sampling from distributed streams

DEFF Research Database (Denmark)

Graham, Cormode; Muthukrishnan, S.; Yi, Ke

2012-01-01

A fundamental problem in data management is to draw and maintain a sample of a large data set, for approximate query answering, selectivity estimation, and query planning. With large, streaming data sets, this problem becomes particularly difficult when the data is shared across multiple distribu......A fundamental problem in data management is to draw and maintain a sample of a large data set, for approximate query answering, selectivity estimation, and query planning. With large, streaming data sets, this problem becomes particularly difficult when the data is shared across multiple...... distributed sites. The main challenge is to ensure that a sample is drawn uniformly across the union of the data while minimizing the communication needed to run the protocol on the evolving data. At the same time, it is also necessary to make the protocol lightweight, by keeping the space and time costs low...... for each participant. In this article, we present communication-efficient protocols for continuously maintaining a sample (both with and without replacement) from k distributed streams. These apply to the case when we want a sample from the full streams, and to the sliding window cases of only the W most...

The link between ethnicity, social disadvantage and mental health problems in a school-based multiethnic sample of children in The Netherlands.

Science.gov (United States)

Adriaanse, Marcia; Veling, Wim; Doreleijers, Theo; van Domburgh, Lieke

2014-11-01

To investigate to what extent differences in prevalence and types of mental health problems between ethnic minority and majority youth can be explained by social disadvantage. Mental health problems were assessed in a sample of 1,278 schoolchildren (55% Dutch, 32% Moroccan and 13% Turkish; mean age: 12.9 ± 1.8) using the Strengths and Difficulties Questionnaire self-report and teacher report. Measures of family socioeconomic status, neighbourhood deprivation, perceived discrimination, family structure, repeating a school year, housing stability and neighbourhood urbanization were used as indicators of social disadvantage, based on which a cumulative index was created. Ethnic minority youth had more externalizing and fewer internalizing problems than majority youth. Perceived discrimination and living in an unstable social environment were associated with mental health problems, independent of ethnicity. A dose-response relationship was found between social disadvantage and mental health problems. The adjusted odds ratio for mental health problems was 4.16 (95% CI 2.49-6.94) for more than four compared with zero indicators of social disadvantage. Social disadvantage was more common in ethnic minority than in majority youth, explaining part of the differences in prevalence of mental health problems. Ethnic minority youth in the Netherlands have a different profile of mental health problems than majority youth. In all ethnic groups, the risk of mental health problems increases with the degree of social disadvantage. The higher prevalence of externalizing problems among ethnic minority youth is explained partly by their disadvantaged social position. The findings suggest that social factors associated with ethnicity are likely to explain mental health problems in ethnic groups.

Modified and fuzzified general problem solver for 'monkey and banana' problem, 2

International Nuclear Information System (INIS)

Sano, Norihide; Takahashi, Ryoichi.

1991-01-01

The automatic operation is important for the in-service inspection of the operating nuclear power station or the decommission of retired plants. The master and slave control will be introduced for work-robot control. It is desirable that the slave involves the capability of problem solving. This paper assumed that the slave involved the general problem solver algorithm. In view of having solved the puzzle of the 'monkey and banana', the slave system is regarded as the reasonable alternative which incorporates the capability of problem solving. Basically, the GPS solves a problem by reducing the difference between an initial state and a goal state, and hence the performance of GPS depends on selecting the difference to be reduced. The usual GPS is given in advance the ordering which indicates the importance of the differences. In this paper, the GPS was improved by making use of the rules which decide the order. When several choices are found on the given difference, the fuzzified decision to determine the action is demonstrated in this paper. (author)

Does forming implementation intentions help people with mental health problems to achieve goals? A meta-analysis of experimental studies with clinical and analogue samples.

Science.gov (United States)

Toli, Agoro; Webb, Thomas L; Hardy, Gillian E

2016-03-01

People struggle to act on the goals that they set themselves, and this gap between intention and action is likely to be exacerbated by mental health problems. Evidence suggests that forming specific if-then plans (or 'implementation intentions') can promote goal attainment and a number of studies have applied such techniques in clinical contexts. However, to date, the extent to which planning can help people with mental health problems has not been systematically examined. The present review used meta-analysis to investigate the effect of if-then planning on goal attainment among people with a DSM-IV/ICD-10 diagnosis (i.e., clinical samples) or scores above a relevant cut-off on clinical measures (i.e., analogue samples). In total, 29 experimental studies, from 18 records, met the inclusion criteria. Excluding one outlying (very large) effect, forming implementation intentions had a large-sized effect on goal attainment (d+ = 0.99, k = 28, N = 1,636). Implementation intentions proved effective across different mental health problems and goals, and in studies with different methodological approaches. Taken together, the findings suggest that forming implementation intentions can be a useful strategy for helping people with mental health problems to achieve various goals and might be usefully integrated into existing treatment approaches. However, further studies are needed addressing a wider range of mental health problems. © 2015 The British Psychological Society.

The principal construction problems of Siloe

International Nuclear Information System (INIS)

Chatoux, J.

1975-06-01

A discussion is given of a number of problems that arose during the various stages of design and construction which could be divided into two main categories: 1) technical administrative and organisational problems which involved the personnel, 2) purely technical problems. (R.L.)

Parent involvement in beginning primary school: Correlates and changes in involvement across the first two years of school in a New Zealand sample.

Science.gov (United States)

McDowall, Philippa S; Taumoepeau, Mele; Schaughency, Elizabeth

2017-06-01

This study described the relations of parents' and teachers' beliefs and attitudes to forms of parents' involvement in children's first two years of primary school. Parents of children in their first year of primary school (age 5) were recruited from 12 classrooms within four schools in New Zealand; 196 families participated in their child's first year, and 124 families continued to participate in their child's second school year. Parents completed the Family-Involvement Questionnaire, New Zealand, and we archivally collected parent-documented children's oral reading homework. Teachers' rated helpfulness of parents' involvement at school (level 2) and parents' rated teacher invitations to be involved and their perceived time and energy (level 1) contributed to school-based involvement in Year 1 in multilevel models, with parents' rated teacher invitations for involvement also found to predict Year 1 home-school communication in regression analyses. Contributors to Year 1 child-parent reading in multilevel models included level 1 predictors of two or more adults in the home and parents' perceived time and energy. Longitudinal analyses suggested both consistency and change in each form of involvement from Year 1 to Year 2, with increases in each form of involvement found to be associated with increases in parents' and/or teachers' views about involvement in Year 2 in cross-sectional time-series analyses. Implications for schools wanting to engage families are that parents' involvement in children's schooling may be influenced by parents' perceptions of their capacity, teachers' engagement efforts, and the school's climate for involvement. This is a special issue paper "Family Engagement in Education and Intervention". Copyright © 2017 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Sampling and sample preparation methods for the analysis of trace elements in biological material

International Nuclear Information System (INIS)

Sansoni, B.; Iyengar, V.

1978-05-01

The authors attempt to give a most systamtic possible treatment of the sample taking and sample preparation of biological material (particularly in human medicine) for trace analysis (e.g. neutron activation analysis, atomic absorption spectrometry). Contamination and loss problems are discussed as well as the manifold problems of the different consistency of solid and liquid biological materials, as well as the stabilization of the sample material. The process of dry and wet ashing is particularly dealt with, where new methods are also described. (RB) [de

College Students Rarely Seek Help Despite Serious Substance Use Problems

Science.gov (United States)

Caldeira, Kimberly M.; Kasperski, Sarah J.; Sharma, Eva; Vincent, Kathryn B.; O’Grady, Kevin E.; Wish, Eric D.; Arria, Amelia M.

2009-01-01

The prevalence of substance use disorders (SUD) and aspects of the help-seeking process among a high-risk sample of 946 students at one large public university were assessed in personal interviews during the first three years of college. After statistically adjusting for purposive sampling, an estimated 46.8%wt of all third-year students met DSM-IV criteria for SUD involving alcohol and/or marijuana at least once. Of 548 SUD cases, 3.6% perceived a need for help with substance use problems; 16.4% were encouraged by someone else to seek help. Help-seeking was rare among SUD cases (8.8%), but significantly elevated among individuals who perceived a need (90.0%) or experienced social pressures from parents (32.5%), friends (34.2%), or another person (58.3%). Resources accessed for help included educational programs (38%), health professionals (27%), and twelve-step programs (19%). College students have high rates of substance use problems but rarely recognize a need for treatment or seek help. Results highlight the opportunity for early intervention with college students with SUD. PMID:19553064

Problems of engineering education and their decision involving industry

Directory of Open Access Journals (Sweden)

R. P. Simonyants

2014-01-01

Full Text Available In Russia, the problems of engineering education are connected with political and economic upheavals of the late last century. At the same time, some leading engineering universities in Russia, such as the Bauman Moscow State Technical University (BMSTU were resistant to the damaging effects of the crisis. But the methodology and experience of their effective work are insufficiently known.The problems of international engineering school development are also known. The first UNESCO World Report on Engineering (2010 assesses the state of engineering education as follows: worldwide shortage of engineers is a threat to the development of society.Based on the analysis of the current state of engineering education in the world and tendencies of development an urgency of its modernization with the focus on the enhancement of practical component has been shown.Topical problems associated with innovations and modernization in engineering education in the field of aerospace technology were discussed at the first international forum, which was held in Beijing Beyhanskom University (BUAA on 8 - 9 September 2012. The author attended this forum and presented his impressions of its work. It was noted that the role of Russia in the global process to form and develop engineering education is ignored. This opinion sounded, generally, in all speakers' reports, apart from ours.The President BUAA, a Professor Jinpeng Huai, and a Professor Qiushi Li. talked about the problems of building the engineering education system in China. It was emphasized that in China a study of engineering education techniques was motivated by the fact that quality assurance of engineering education at U.S. universities does not meet requirements.Attention is drawn to Dr. David Wisler's report who is a representative of the U.S. aerospace industry (General Electric Aviation corporation, actively promoting networking technology "initiative CDIO».The assessment of the engineering education

Sampling of systematic errors to estimate likelihood weights in nuclear data uncertainty propagation

International Nuclear Information System (INIS)

Helgesson, P.; Sjöstrand, H.; Koning, A.J.; Rydén, J.; Rochman, D.; Alhassan, E.; Pomp, S.

2016-01-01

In methodologies for nuclear data (ND) uncertainty assessment and propagation based on random sampling, likelihood weights can be used to infer experimental information into the distributions for the ND. As the included number of correlated experimental points grows large, the computational time for the matrix inversion involved in obtaining the likelihood can become a practical problem. There are also other problems related to the conventional computation of the likelihood, e.g., the assumption that all experimental uncertainties are Gaussian. In this study, a way to estimate the likelihood which avoids matrix inversion is investigated; instead, the experimental correlations are included by sampling of systematic errors. It is shown that the model underlying the sampling methodology (using univariate normal distributions for random and systematic errors) implies a multivariate Gaussian for the experimental points (i.e., the conventional model). It is also shown that the likelihood estimates obtained through sampling of systematic errors approach the likelihood obtained with matrix inversion as the sample size for the systematic errors grows large. In studied practical cases, it is seen that the estimates for the likelihood weights converge impractically slowly with the sample size, compared to matrix inversion. The computational time is estimated to be greater than for matrix inversion in cases with more experimental points, too. Hence, the sampling of systematic errors has little potential to compete with matrix inversion in cases where the latter is applicable. Nevertheless, the underlying model and the likelihood estimates can be easier to intuitively interpret than the conventional model and the likelihood function involving the inverted covariance matrix. Therefore, this work can both have pedagogical value and be used to help motivating the conventional assumption of a multivariate Gaussian for experimental data. The sampling of systematic errors could also

Measuring Radionuclides in the environment: radiological quantities and sampling designs

International Nuclear Information System (INIS)

Voigt, G.

1998-10-01

One aim of the workshop was to support and provide an ICRU report committee (International Union of Radiation Units) with actual information on techniques, data and knowledge of modern radioecology when radionuclides are to be measured in the environment. It has been increasingly recognised that some studies in radioecology, especially those involving both field sampling and laboratory measurements, have not paid adequate attention to the problem of obtaining representative, unbiased samples. This can greatly affect the quality of scientific interpretation, and the ability to manage the environment. Further, as the discipline of radioecology has developed, it has seen a growth in the numbers of quantities and units used, some of which are ill-defined and which are non-standardised. (orig.)

Interaction matters: quantifying conduct problem × depressive symptoms interaction and its association with adolescent alcohol, cigarette, and marijuana use in a national sample.

Science.gov (United States)

Maslowsky, Julie; Schulenberg, John E

2013-11-01

Substance use is a major contributor to morbidity and mortality among American adolescents. Conduct problems and depressive symptoms have each been found to be associated with adolescent substance use. Although they are highly comorbid, the role of the interaction of conduct problems and depressive symptoms in substance use is not clear. In national samples of 8th-, 10th-, and 12th-grade students from the Monitoring the Future study, latent moderated structural equation modeling was used to estimate the association of conduct problems, depressive symptoms, and their interaction to the use of alcohol (including binge drinking), cigarettes, and marijuana. Moderation by age and sex was tested. The interaction of conduct problems with depressive symptoms was a strong predictor of substance use, particularly among younger adolescents. With few exceptions, adolescents with high levels of both conduct problems and depressive symptoms used substances most frequently. Conduct problems were a strong positive predictor of substance use, and depressive symptoms were a weak positive predictor. Whereas conduct problems are often thought to be a primary predictor of substance use, this study revealed that depressive symptoms potentiate the relation of conduct problems to substance use. Therefore, substance use prevention efforts should target both depressive symptoms and conduct problems.

Effect of the sample matrix on measurement uncertainty in X-ray fluorescence analysis

International Nuclear Information System (INIS)

Morgenstern, P.; Brueggemann, L.; Wennrich, R.

2005-01-01

The estimation of measurement uncertainty, with reference to univariate calibration functions, is discussed in detail in the Eurachem Guide 'Quantifying Uncertainty in Analytical Measurement'. The adoption of these recommendations to quantitative X-ray fluorescence analysis (XRF) involves basic problems which are above all due to the strong influence of the sample matrix on the analytical response. In XRF-analysis, the proposed recommendations are consequently applicable only to the matrix corrected response. The application is also restricted with regard to both the matrices and analyte concentrations. In this context the present studies are aimed at the problems to predict measurement uncertainty also with reference to more variable sample compositions. The corresponding investigations are focused on the use of the intensity of the Compton scattered tube line as an internal standard to assess the effect of the individual sample matrix on the analytical response relatively to a reference matrix. Based on this concept the estimation of the measurement uncertainty of an analyte presented in an unknown specimen can be predicted in consideration of the data obtained under defined matrix conditions

Rich Vehicle Routing Problems and Applications

DEFF Research Database (Denmark)

Wen, Min

very short computational time on real-life data involving up to 200 pairs of suppliers and customers. The second problem we consider is a dynamic vehicle routing problem with multiple objectives over a planning horizon that consists of multiple periods. In this problem, customer orders are revealed...... the company’s solution in terms of all the objectives, including the travel time, customer waiting and daily workload balances, under the given constraints considered in the work. Finally, we address an integrated vehicle routing and driver scheduling problem, in which a large number of practical constraints....... The method is implemented and tested on real-life data involving up to 2000 orders. It is shown that the method is able to provide solutions of good quality within reasonable running time....

A Boundary Element Solution to the Problem of Interacting AC Fields in Parallel Conductors

Directory of Open Access Journals (Sweden)

Einar M. Rønquist

1984-04-01

Full Text Available The ac fields in electrically insulated conductors will interact through the surrounding electromagnetic fields. The pertinent field equations reduce to the Helmholtz equation inside each conductor (interior problem, and to the Laplace equation outside the conductors (exterior problem. These equations are transformed to integral equations, with the magnetic vector potential and its normal derivative on the boundaries as unknowns. The integral equations are then approximated by sets of algebraic equations. The interior problem involves only unknowns on the boundary of each conductor, while the exterior problem couples unknowns from several conductors. The interior and the exterior problem are coupled through the field continuity conditions. The full set of equations is solved by standard Gaussian elimination. We also show how the total current and the dissipated power within each conductor can be expressed as boundary integrals. Finally, computational results for a sample problem are compared with a finite difference solution.

Inverse logarithmic potential problem

CERN Document Server

Cherednichenko, V G

1996-01-01

The Inverse and Ill-Posed Problems Series is a series of monographs publishing postgraduate level information on inverse and ill-posed problems for an international readership of professional scientists and researchers. The series aims to publish works which involve both theory and applications in, e.g., physics, medicine, geophysics, acoustics, electrodynamics, tomography, and ecology.

Sampling informative/complex a priori probability distributions using Gibbs sampling assisted by sequential simulation

DEFF Research Database (Denmark)

Hansen, Thomas Mejer; Mosegaard, Klaus; Cordua, Knud Skou

2010-01-01

Markov chain Monte Carlo methods such as the Gibbs sampler and the Metropolis algorithm can be used to sample the solutions to non-linear inverse problems. In principle these methods allow incorporation of arbitrarily complex a priori information, but current methods allow only relatively simple...... this algorithm with the Metropolis algorithm to obtain an efficient method for sampling posterior probability densities for nonlinear inverse problems....

Sleep problems and daytime problem behaviours in children with intellectual disablity

NARCIS (Netherlands)

Didden, H.C.M.; Korzilius, H.P.L.M.; Aperloo, B. van; Overloon, C. van; Vries, M. de

2002-01-01

BACKGROUND: Sleep problems are common among children with intellectual disability (ID). METHOD: The present study assessed the prevalence of severe sleep problems in a sample of children (n=286) with mild to profound ID who lived at home with their parents(s) in the Netherlands. It also

The Efficacy and Development of Students' Problem-Solving Strategies During Compulsory Schooling: Logfile Analyses.

Science.gov (United States)

Molnár, Gyöngyvér; Csapó, Benő

2018-01-01

The purpose of this study was to examine the role of exploration strategies students used in the first phase of problem solving. The sample for the study was drawn from 3 rd - to 12 th -grade students (aged 9-18) in Hungarian schools ( n = 4,371). Problems designed in the MicroDYN approach with different levels of complexity were administered to the students via the eDia online platform. Logfile analyses were performed to ascertain the impact of strategy use on the efficacy of problem solving. Students' exploration behavior was coded and clustered through Latent Class Analyses. Several theoretically effective strategies were identified, including the vary-one-thing-at-a-time (VOTAT) strategy and its sub-strategies. The results of the analyses indicate that the use of a theoretically effective strategy, which extract all information required to solve the problem, did not always lead to high performance. Conscious VOTAT strategy users proved to be the best problem solvers followed by non-conscious VOTAT strategy users and non-VOTAT strategy users. In the primary school sub-sample, six qualitatively different strategy class profiles were distinguished. The results shed new light on and provide a new interpretation of previous analyses of the processes involved in complex problem solving. They also highlight the importance of explicit enhancement of problem-solving skills and problem-solving strategies as a tool for knowledge acquisition in new contexts during and beyond school lessons.

The Efficacy and Development of Students' Problem-Solving Strategies During Compulsory Schooling: Logfile Analyses

Science.gov (United States)

Molnár, Gyöngyvér; Csapó, Benő

2018-01-01

The purpose of this study was to examine the role of exploration strategies students used in the first phase of problem solving. The sample for the study was drawn from 3rd- to 12th-grade students (aged 9–18) in Hungarian schools (n = 4,371). Problems designed in the MicroDYN approach with different levels of complexity were administered to the students via the eDia online platform. Logfile analyses were performed to ascertain the impact of strategy use on the efficacy of problem solving. Students' exploration behavior was coded and clustered through Latent Class Analyses. Several theoretically effective strategies were identified, including the vary-one-thing-at-a-time (VOTAT) strategy and its sub-strategies. The results of the analyses indicate that the use of a theoretically effective strategy, which extract all information required to solve the problem, did not always lead to high performance. Conscious VOTAT strategy users proved to be the best problem solvers followed by non-conscious VOTAT strategy users and non-VOTAT strategy users. In the primary school sub-sample, six qualitatively different strategy class profiles were distinguished. The results shed new light on and provide a new interpretation of previous analyses of the processes involved in complex problem solving. They also highlight the importance of explicit enhancement of problem-solving skills and problem-solving strategies as a tool for knowledge acquisition in new contexts during and beyond school lessons. PMID:29593606

Encouraging Sixth-Grade Students' Problem-Solving Performance by Teaching through Problem Solving

Science.gov (United States)

Bostic, Jonathan D.; Pape, Stephen J.; Jacobbe, Tim

2016-01-01

This teaching experiment provided students with continuous engagement in a problem-solving based instructional approach during one mathematics unit. Three sections of sixth-grade mathematics were sampled from a school in Florida, U.S.A. and one section was randomly assigned to experience teaching through problem solving. Students' problem-solving…

Soil sampling

International Nuclear Information System (INIS)

Fortunati, G.U.; Banfi, C.; Pasturenzi, M.

1994-01-01

This study attempts to survey the problems associated with techniques and strategies of soil sampling. Keeping in mind the well defined objectives of a sampling campaign, the aim was to highlight the most important aspect of representativeness of samples as a function of the available resources. Particular emphasis was given to the techniques and particularly to a description of the many types of samplers which are in use. The procedures and techniques employed during the investigations following the Seveso accident are described. (orig.)

Associations between work family conflict, emotional exhaustion, musculoskeletal pain, and gastrointestinal problems in a sample of business travelers.

Science.gov (United States)

Jensen, Maria Therese; Rundmo, Torbjørn

2015-02-01

The aim of the study was to examine the associations among work-family conflict (WFC), emotional exhaustion, musculoskeletal (MS) pain, and gastrointestinal problems on a sample of business travelers (n = 2,093). An additional aim was to examine differences in the mentioned relationships among three traveler groups: commuters, national travelers, and international travelers. The study was conducted in a large Norwegian oil and gas company, and the company's business travel database was utilized to examine business travel. Structural equation modeling (SEM) revealed significant relations between WFC and emotional exhaustion and between emotional exhaustion and health problems. Contrary to the expectations, no direct association was found between WFC and health problems. However, we found that emotional exhaustion mediated the relation between WFC and health outcomes. The results from multi-group analysis revealed that associations among WFC, emotional exhaustion, and health-outcomes showed a similar pattern for commuters, national travelers, and international travelers. However, the association between emotional exhaustion and MS pain proved to be significantly stronger for the commuter group compared to the national and international travel groups. Practical implications and the consequences of these findings for future research are discussed. © 2014 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Personal values and involvement in problem behaviors among Bahamian early adolescents: a cross-sectional study.

Science.gov (United States)

Liu, Hongjie; Yu, Shuli; Cottrell, Lesley; Lunn, Sonja; Deveaux, Lynette; Brathwaite, Nanika V; Marshall, Sharon; Li, Xiaoming; Stanton, Bonita

2007-07-02

Few studies, particularly in developing countries, have explored the relationship between adolescents and parental values with adolescent problem behaviors. The objectives of the study are to (1) describe adolescents' personal values, their problem behaviors, and the relationships thereof according to gender and (2) examine the relationship between parental values, adolescent values, and adolescents' problem behaviors among sixth-grade students and one of their parents. The data used in these analyses were from the baseline assessment of a school-based HIV risk reduction intervention being conducted and evaluated among sixth grade students and one of their parents across 9 elementary schools in The Bahamas. Personal values were measured by the Portrait Values Questionnaire (PVQ). Seven reported problem behaviors were queried from the students, which included physical fight with a friend, drank alcohol, beer, or wine, smoked a cigarette, pushed or carried any drugs, carried a gun, knife, screwdriver or cutlass to use as a weapon, had sex and used marijuana or other illicit drugs over the past 6 months. Multilevel modeling for binary data was performed to estimate the associations between adolescent and parental values and adolescent problem behaviors. Among 785 students, 47% of the students reported at least one problem behavior. More boys (54%) reported having one or more problem behaviors than girls (41%, p values (self-transcendence and conservation) were low or modestly correlated with youth' values (openness to change and self-enhancement). Parental-reported values documented limited association on adolescents' reported values and behaviors. In designing interventions for reducing adolescents' problem behaviors, it may be important to understand the values associated with specific problem behaviors. Further exploration regarding lack of association between adolescent and parental values and problem behaviors is needed.

PEMBELAJARAN THINK PAIR SHARE BERBASIS CREATIVE PROBLEM SOLVING UNTUK MENINGKATKAN HASIL BELAJAR

Directory of Open Access Journals (Sweden)

Rizki Wulandari

2015-11-01

Full Text Available This study was motivated by the lack of student learning outcomes and involvement of the student in class XI of High School in Kudus especially on solubility and solubility results subject. Think pair share learning model based on creative problem solving was applied to overcome these problems. This study aimed to determine the improvement of student learning outcomes. The experiment was conducted on an experimental basis, with the entire population  of high school students of class XI. Sampling was done by using cluster random sampling, so then obtained XI IPA 3 class as the experimental class and XI IPA 1 class as the control class. The data of increasing students' cognitive learning outcomes derived from the test multiple choice questions, while the data psychomotor and affective learning outcomes of students were from the observation sheet. The result of data analysis showed an increase in learning outcomes and student activity. In addition, an increase in cognitive learning outcomes classical achieved completeness. It can be concluded that the application of the think pair share learning model based on creative problem solving can improve student learning outcomes.

Does burnout among doctors affect their involvement in patients' mental health problems? A study of videotaped consultations

Directory of Open Access Journals (Sweden)

de Bakker Dinny H

2009-08-01

Full Text Available Abstract Background General practitioners' (GPs' feelings of burnout or dissatisfaction may affect their patient care negatively, but it is unknown if these negative feelings also affect their mental health care. GPs' available time, together with specific communication tools, are important conditions for providing mental health care. We investigated if GPs who feel burnt out or dissatisfied with the time available for their patients, are less inclined to encourage their patients to disclose their distress, and have shorter consultations, in order to gain time and energy. This may result in less psychological evaluations of patients' complaints. Methods We used 1890 videotaped consultations from a nationally representative sample of 126 Dutch GPs to analyse GPs' communication and the duration of their consultations. Burnout was subdivided into emotional exhaustion, depersonalisation and reduced accomplishment. Multilevel regression analyses were used to investigate which subgroups of GPs differed significantly. Results GPs with feelings of exhaustion or dissatisfaction with the available time have longer consultations compared to GPs without these feelings. Exhausted GPs, and GPs with feelings of depersonalisation, talk more about psychological or social topics in their consultations. GPs with feelings of reduced accomplishment are an exception: they communicate less affectively, are less patient-centred and have less eye contact with their patients compared to GPs without reduced accomplishment. We found no relationship between GPs' feelings of burnout or dissatisfaction with the available time and their psychological evaluations of patients' problems. Conclusion GPs' feelings of burnout or dissatisfaction with the time available for their patients do not obstruct their diagnosis and awareness of patients' psychological problems. On the contrary, GPs with high levels of exhaustion or depersonalisation, and GPs who are dissatisfied with the

Gardner's Two Children Problems and Variations: Puzzles with Conditional Probability and Sample Spaces

Science.gov (United States)

Taylor, Wendy; Stacey, Kaye

2014-01-01

This article presents "The Two Children Problem," published by Martin Gardner, who wrote a famous and widely-read math puzzle column in the magazine "Scientific American," and a problem presented by puzzler Gary Foshee. This paper explains the paradox of Problems 2 and 3 and many other variations of the theme. Then the authors…

Macau parents’ perceptions of underage children’s gambling involvement

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Ernest Moon Tong So

2017-03-01

Full Text Available Abstract Objectives The study examined Macau parents’ perceptions of underage children’s gambling involvement, and parents’ attitudes towards help seeking if their children had a gambling problem. The parents’ gambling behavior in the past year was also investigated. Methods This is a parent survey using a self-administered questionnaire. A convenience sample of 311 Macau parents (106 fathers and 205 mothers with underage children aged 3–17 years was recruited. The response rate is 77.8%. The participants were asked if they had ever approved or taught their underage children to gamble, and how did they award their children when they won in gambling games. The parents were also asked if they had gambled in the previous 12 months, and their gambling behavior was assessed by the Chinese Problem Gambling Severity Index (CPGSI. Results Half of the parents surveyed (52% did not approve underage gambling but 81% taught their underage children to play different gambling games. Children were awarded with money (55%, praises (17.5%, toys (15% and food (12.5% when they won in games. One-fifth (20.6% were distressed with their children’s gambling problem. Many (68.8% were willing to seek help to cope with children’s gambling problems. Only 21.2% (n = 66 of the parents reported gambling in the past year. Using the CPGSI, 4.5% of these gamblers could be identified as problem gamblers, and 16.7% were moderate-risk gamblers. Conclusion The study results indicate parent education should be included in prevention of underage gambling.

Problem solving therapy - use and effectiveness in general practice.

Science.gov (United States)

Pierce, David

2012-09-01

Problem solving therapy (PST) is one of the focused psychological strategies supported by Medicare for use by appropriately trained general practitioners. This article reviews the evidence base for PST and its use in the general practice setting. Problem solving therapy involves patients learning or reactivating problem solving skills. These skills can then be applied to specific life problems associated with psychological and somatic symptoms. Problem solving therapy is suitable for use in general practice for patients experiencing common mental health conditions and has been shown to be as effective in the treatment of depression as antidepressants. Problem solving therapy involves a series of sequential stages. The clinician assists the patient to develop new empowering skills, and then supports them to work through the stages of therapy to determine and implement the solution selected by the patient. Many experienced GPs will identify their own existing problem solving skills. Learning about PST may involve refining and focusing these skills.

A Monte Carlo Metropolis-Hastings Algorithm for Sampling from Distributions with Intractable Normalizing Constants

KAUST Repository

Liang, Faming; Jin, Ick-Hoon

2013-01-01

Simulating from distributions with intractable normalizing constants has been a long-standing problem inmachine learning. In this letter, we propose a new algorithm, the Monte Carlo Metropolis-Hastings (MCMH) algorithm, for tackling this problem. The MCMH algorithm is a Monte Carlo version of the Metropolis-Hastings algorithm. It replaces the unknown normalizing constant ratio by a Monte Carlo estimate in simulations, while still converges, as shown in the letter, to the desired target distribution under mild conditions. The MCMH algorithm is illustrated with spatial autologistic models and exponential random graph models. Unlike other auxiliary variable Markov chain Monte Carlo (MCMC) algorithms, such as the Møller and exchange algorithms, the MCMH algorithm avoids the requirement for perfect sampling, and thus can be applied to many statistical models for which perfect sampling is not available or very expensive. TheMCMHalgorithm can also be applied to Bayesian inference for random effect models and missing data problems that involve simulations from a distribution with intractable integrals. © 2013 Massachusetts Institute of Technology.

A Monte Carlo Metropolis-Hastings Algorithm for Sampling from Distributions with Intractable Normalizing Constants

KAUST Repository

Liang, Faming

2013-08-01

Simulating from distributions with intractable normalizing constants has been a long-standing problem inmachine learning. In this letter, we propose a new algorithm, the Monte Carlo Metropolis-Hastings (MCMH) algorithm, for tackling this problem. The MCMH algorithm is a Monte Carlo version of the Metropolis-Hastings algorithm. It replaces the unknown normalizing constant ratio by a Monte Carlo estimate in simulations, while still converges, as shown in the letter, to the desired target distribution under mild conditions. The MCMH algorithm is illustrated with spatial autologistic models and exponential random graph models. Unlike other auxiliary variable Markov chain Monte Carlo (MCMC) algorithms, such as the Møller and exchange algorithms, the MCMH algorithm avoids the requirement for perfect sampling, and thus can be applied to many statistical models for which perfect sampling is not available or very expensive. TheMCMHalgorithm can also be applied to Bayesian inference for random effect models and missing data problems that involve simulations from a distribution with intractable integrals. © 2013 Massachusetts Institute of Technology.

Problems of drawing up standards for persons simultaneously engaged in more than one activity involving radiation hazards

International Nuclear Information System (INIS)

Lucci, F.; Pelliccioni, M.

1979-01-01

The authors examine, from the points of view of the ICRP recommendations and of national and international standards, radiation protection problems posed by persons simultaneously engaged in professional activities involving radiation hazards in more than one place. The consequences of this type of situation, for the radiological protection classification of workers and for the evaluation and recording of doses received, are described in detail. In order to ensure proper monitoring of doses, agreements must be reached in advance between those in charge of the different areas of activity. Three cases seem to be of particular relevance: (a) that of workers who, while working for a single employer, perform in more than one place activities in which they are exposed to ionizing radiation (scientists working at different research centres, employees of companies specialized in the nuclear field, including the use of isotopes, accelerators, etc.); (b) that of workers who are engaged by more than one employer and are exposed to ionizing radiations as a result of their activities at different establishments (a special case is that of doctors who are radiologists or specialists in some other branch of nuclear medicine and work both as employees and independently in their own practices); and (c) that of employees of outside organizations not directly concerned with nuclear activities who are only exposed to ionizing radiation when called upon to work in establishments possessing sources of radiation. Finally, the authors suggest some ways of solving these problems - though they are rather difficult to define objectively (for example the case of medical practioners). (author)

Problems associated with use of the logarithmic equivalent strain in high pressure torsion

International Nuclear Information System (INIS)

Jonas, J J; Aranas, C Jr

2014-01-01

The logarithmic 'equivalent' strain is frequently recommended for description of the experimental flow curves determined in high pressure torsion (HPT) tests. Some experimental results determined at -196 and 190 °C on a 2024 aluminum alloy are plotted using both the von Mises and logarithmic equivalent strains. Three types of problems associated with use of the latter are described. The first involves the lack of work conjugacy between the logarithmic and shear stress/shear strain curves, a topic that has been discussed earlier. The second concerns the problems associated with testing at constant logarithmic strain rate, a feature of particular importance when the material is rate sensitive. The third type of problem involves the 'history dependence' of this measure in that the incremental logarithmic strain depends on whether the prior strain accumulated in the sample is known or not. This is a difficulty that does not affect use of the von Mises equivalent strain. For these reasons, it is concluded that the qualifier 'equivalent' should not be used when the logarithmic strain is employed to describe HPT results

Attention Problems Mediate the Association between Severity of Physical Abuse and Aggressive Behavior in a Sample of Maltreated Early Adolescents

OpenAIRE

Garrido, Edward F.; Taussig, Heather N.; Culhane, Sara E.; Raviv, Tali

2011-01-01

Empirical evidence has accumulated documenting an association between childhood physical abuse and aggressive behavior. Relatively fewer studies have explored possible mediating mechanisms that may explain this association. The purpose of the current study was to examine whether caregiver- and youth-reported attention problems mediate the association between physical abuse severity and aggressive behavior. A sample of 240 maltreated early adolescents (ages 9–11) and their caregivers were inte...

Initial Reliability and Validity of the Life Satisfaction Scale for Problem Youth in a Sample of Drug Abusing and Conduct Disordered Youth

Science.gov (United States)

Donohue, Brad; Teichner, Gordon; Azrin, Nathan; Weintraub, Noah; Crum, Thomas A.; Murphy, Leah; Silver, N. Clayton

2003-01-01

Responses to Life Satisfaction Scale for Problem Youth (LSSPY) items were examined in a sample of 193 substance abusing and conduct disordered adolescents. In responding to the LSSPY, youth endorse their percentage of happiness (0 to 100%) in twelve domains (i.e., friendships, family, school, employment/work, fun activities, appearance, sex…

THE EFFECT OF BRAND LOYALTY OF INVOLVEMENT TO PRODUCTS: THE SAMPLE OF MOBILE PHONE

OpenAIRE

Armagan, Ece; Akel, Gokhan

2017-01-01

Brands in a highly competitive environment is consideredas the main assets of businesses, businesses that create brand loyalty ensuresthat there is a long period of time. In order to ensure brand loyalty alsoconsumers’ involvement need to be investigated. Brand loyalty is also a greatbenefit in understanding consumers' level of involvement on the brand. Theproduct involvement required to understand consumer behavior is an importantfactor on brand loyalty. In this study, the effect of the...

Problem Solving, Scaffolding and Learning

Science.gov (United States)

Lin, Shih-Yin

2012-01-01

Helping students to construct robust understanding of physics concepts and develop good solving skills is a central goal in many physics classrooms. This thesis examine students' problem solving abilities from different perspectives and explores strategies to scaffold students' learning. In studies involving analogical problem solving…

#SochiProblems: Ignorance or Arrogance? / #SochiProblems: ¿ignorancia o arrogancia?

Directory of Open Access Journals (Sweden)

Alexander V. Laskin

2014-10-01

Full Text Available The study focuses on the twitter conversations about the XXII Winter Olympics Games in Sochi, Russia. Specifically, the study collects and performs content analysis of the tweets tagged with the hashtag #SochiProblems. This study draws a random sample of tweets from every day of the games to achieve a 99% confidence level with 5% confidence interval and uses the framing theory to analyze this sample. The results allow us to determine what substantive and affective frames dominated in the twitter conversations tagged with #SochiProblems hashtag and what was the main focus of the tweets’ content.

Carotenoid determination in recent marine sediments - practical problems during sample preparation and HPLC analysis

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Magdalena Krajewska

2017-05-01

Full Text Available An analytical procedure for the analysis of carotenoids in marine sediments rich in organic matter has been developed. Analysis of these compounds is difficult; the application of methods used by other authors required optimization for the samples studied here. The analytical procedure involved multiple ultrasound-assisted extraction with acetone followed by liquid-liquid extraction (acetone extract:benzene:water - 15:1:10 v/v/v and HPLC analysis. The influence of column temperature on pigment separation and the quantification method were investigated – a temperature of 5 °C was selected for the Lichrospher 100 RP-18e column. The pigments in the sediment extract were quantified using a method based on HPLC analysis (at 450 nm and spectrophotometric measurements (at 450 nm, and extinction coefficients were determined for standard solutions at this wavelength. It is very important to use the value of the extinction coefficient appropriate to the wavelength at which the detection of carotenoids was carried out.

The effects of presenting multidigit mathematics problems in a realistic context on sixth graders' problem solving

NARCIS (Netherlands)

Hickendorff, M.

2013-01-01

Mathematics education and assessments increasingly involve arithmetic problems presented in context: a realistic situation that requires mathematical modeling. This study assessed the effects of such typical school mathematics contexts on two aspects of problem solving: performance and strategy use.

Interrelationships between LGBT-Based Victimization, Suicide, and Substance Use Problems in a Diverse Sample of Sexual and Gender Minority Men and Women

Science.gov (United States)

Mereish, Ethan H.; O'Cleirigh, C; Bradford, Judith B.

2013-01-01

Research has documented significant relationships between sexual and gender minority stress and higher rates of suicidality (i.e., suicidal ideation and attempts) and substance use problems. We examined the potential mediating role of substance use problems on the relationship between sexual and gender minority stress (i.e., victimization based on lesbian, gay, bisexual, or transgender identity; LGBT) and suicidality. A non-probability sample of LGBT patients from a community health center (N = 1457) ranged in age 19 to 70 years. Participants reported history of lifetime suicidal ideation and attempts, and substance use problems, as well as experiences of LGBT-based verbal and physical attacks. Substance use problems were a significant partial mediator between LGBT-based victimization and suicidal ideation and between LGBT-based victimization and suicide attempts for sexual and gender minorities. Nuanced gender differences revealed that substance use problems did not significantly mediate the relationship between victimization and suicide attempts for sexual minority men. Substance use problems may be one insidious pathway that partially mediates the risk effects of sexual and gender minority stress on suicidality. Substances might be a temporary and deleterious coping resource in response to LGBT-based victimization, which have serious effects on suicidal ideation and behaviors. PMID:23535038

Dimensions of problem based learning

DEFF Research Database (Denmark)

Nielsen, Jørgen Lerche; Andreasen, Lars Birch

2013-01-01

The article contributes to the literature on problem based learning and problem-oriented project work, building on and reflecting the experiences of the authors through decades of work with problem-oriented project pedagogy. The article explores different dimensions of problem based learning such...... and Learning (MIL). We discuss changes in the roles of the teachers as supervisors within this learning environment, and we explore the involvement of students as active participants and co-designers of how course and project activities unfold....

The link between infant regulatory problems, temperament traits, maternal depressive symptoms and children's psychopathological symptoms at age three: a longitudinal study in a German at-risk sample.

Science.gov (United States)

Sidor, Anna; Fischer, Cristina; Cierpka, Manfred

2017-01-01

Difficult conditions during childhood can limit an individual's development in many ways. Factors such as being raised in an at-risk family, child temperamental traits or maternal traits can potentially influence a child's later behaviour. The present study investigated the extent of regulatory problems in 6-month-old infants and their link to temperamental traits and impact on externalizing and internalizing problems at 36 months. Moderating effects of maternal distress and maternal depressive symptoms were tested as well. In a quasi-experimental, longitudinal study, a sample of 185 mother-infant dyads at psychosocial risk was investigated at 6 months with SFS (infants' regulatory problems) and at 3 years with CBCL (children's behavioural problems), EAS (children's temperament), ADS (maternal depressive symptoms) and PSI-SF (maternal stress). A hierarchical regression analysis yielded a significant association between infants' regulatory problems and both externalizing and internalizing behaviour problems at age 3 (accounting for 16% and 14% variance), with both externalizing and internalizing problems being linked to current maternal depressive symptoms (12 and 9% of the variance). Externalizing and internalizing problems were found to be related also to children's temperamental difficulty (18 and 13% of variance) and their negative emotionality. With temperamental traits having been taken into account, only feeding problems at 6 months contributed near-significant to internalizing problems at 3 years. Our results underscore the crucial role of temperament in the path between early regulatory problems and subsequent behavioural difficulties. Children's unfavourable temperamental predispositions such as negative emotionality and generally "difficult temperament" contributed substantially to both externalizing and internalizing behavioural problems in the high-risk sample. The decreased predictive power of regulatory problems following the inclusion of

Solved problems in electrochemistry

International Nuclear Information System (INIS)

Piron, D.L.

2004-01-01

This book presents calculated solutions to problems in fundamental and applied electrochemistry. It uses industrial data to illustrate scientific concepts and scientific knowledge to solve practical problems. It is subdivided into three parts. The first uses modern basic concepts, the second studies the scientific basis for electrode and electrolyte thermodynamics (including E-pH diagrams and the minimum energy involved in transformations) and the kinetics of rate processes (including the energy lost in heat and in parasite reactions). The third part treats larger problems in electrolysis and power generation, as well as in corrosion and its prevention. Each chapter includes three sections: the presentation of useful principles; some twenty problems with their solutions; and, a set of unsolved problems

Sampled-data and discrete-time H2 optimal control

NARCIS (Netherlands)

Trentelman, Harry L.; Stoorvogel, Anton A.

1993-01-01

This paper deals with the sampled-data H2 optimal control problem. Given a linear time-invariant continuous-time system, the problem of minimizing the H2 performance over all sampled-data controllers with a fixed sampling period can be reduced to a pure discrete-time H2 optimal control problem. This

Neighborhood Qualification of the Association between Parenting and Problem Behavior Trajectories among Mexican-origin Father-Adolescent Dyads

Science.gov (United States)

White, Rebecca M. B.; Liu, Yu; Gonzales, Nancy A.; Knight, George P.; Tein, Jenn-Yun

2016-01-01

To address the combined importance of fathers and neighborhoods for adolescent adjustment, we examined whether associations between fathers' parenting and adolescents' problem behaviors were qualified by neighborhood adversity. We captured both mainstream (e.g., authoritative) and alternative (e.g., no-nonsense, reduced involvement) parenting styles and examined parenting and neighborhood effects on changes over time in problem behaviors among a sample of Mexican-origin father-adolescent dyads (N = 462). Compared to their counterparts in low-adversity neighborhoods, adolescents in high-adversity neighborhoods experienced greater initial benefits from authoritative fathering, greater long-term benefits from no-nonsense fathering, and fewer costs associated with reduced involvement fathering. The combined influences of alternative paternal parenting styles and neighborhood adversity may set ethnic and racial minority adolescents on different developmental pathways to competence. PMID:28453217

Involvement of family members in life with type 2 diabetes

DEFF Research Database (Denmark)

Grabowski, Dan; Andersen, Tue Helms; Varming, Annemarie

2017-01-01

OBJECTIVES: Family involvement plays a key role in diabetes management. Problems and challenges related to type 2-diabetes often affect the whole family, and relatives are at increased risk of developing diabetes themselves. We highlight these issues in our objectives: (1) to uncover specific...... family problems associated with mutual involvement in life with type 2-diabetes and (2) to analytically look at ways of approaching these problems in healthcare settings. METHODS: Qualitative data were gathered in participatory problem assessment workshops. The data were analysed in three rounds using...... radical hermeneutics. RESULTS: Problems were categorized in six domains: knowledge, communication, support, everyday life, roles and worries. The final cross-analysis focusing on the link between family identity and healthcare authenticity provided information on how the six domains can be approached...

Critical Thinking and Problem Solving Skills in Mathematics of Grade-7 Public Secondary Students

Directory of Open Access Journals (Sweden)

Emil C. Alcantara

2017-11-01

Full Text Available The study aimed to assess the academic performance, critical thinking skills, and problem solving skills in mathematics of Grade-7 students in the five central public secondary schools of Area 2, Division of Batangas, Philippines. This study utilized descriptive method of research. Three hundred forty one (341 students of the public secondary schools out of the total of 2,324 Grade-7 students were selected through systematic random sampling as the subjects of the study. It was found out that the level of performance in Mathematics of the Grade-7 students is proficient. The level of critical thinking skills of students from the different schools is above average as well as their level of problem solving skills. The mathematics performance of the students is positively correlated to their level of critical thinking skills and problem solving skills. Students considered the following learning competencies in the different content areas of Grade-7 Mathematics as difficult to master: solving problems involving sets, describing the development of measurement from the primitive to the present international system of units, finding a solution of an equation or inequality involving one variable, using compass and straightedge to bisect line segments and angles, and analyzing, interpreting accurately and drawing conclusions from graphic and tabular presentations of statistical data.

Fluoroquinolone antibiotics in environmental waters: sample preparation and determination.

Science.gov (United States)

Speltini, Andrea; Sturini, Michela; Maraschi, Federica; Profumo, Antonella

2010-04-01

The aim of this review is to provide a general overview on the analytical methods proposed in the last decade for trace fluoroquinolone (FQ) determination in environmental waters. A large number of studies have been developed on this topic in reason of the importance of their monitoring in the studies of environmental mobility and potential degradation pathways. Every step of the analysis has been carefully considered, with a particular attention to sample preparation, in relationship with the problems involved in the analysis of real matrices. The different strategies to minimise interference from organic matter and to achieve optimal sensitivity, especially important in those samples with lower FQ concentrations, were also highlighted. Results and progress in this field have been described and critically commented. Moreover, a worldwide overview on the presence of FQs in the environmental waters has been reported.

Charge-transfer collisions involving few-electron systems

International Nuclear Information System (INIS)

Kirchner, T.

2016-01-01

Ion-atom collision systems that involve more than one electron constitute nonseparable few-body problems, whose full solution is difficult to say the least. At impact energies well below 1 keV/amu an expansion of the stationary scattering wave function in terms of a limited number of products of nuclear and molecular state wave functions (amended to satisfy scattering boundary conditions) is feasible and usually sufficient to obtain accurate charge-transfer cross sections provided the electronic wave functions include configuration interaction. At energies above 1 keV/amu this approach becomes inefficient and close-coupling methods within the semi classical approximation are better suited to treat the problem. For bare-ion collisions from helium target atoms explicit solutions of the two-electron time-dependent Schrödinger equation can be achieved, but are computationally costly and cannot be extended to problems which involve more than two electrons.

Readiness for Solving Story Problems.

Science.gov (United States)

Dunlap, William F.

1982-01-01

Readiness activities are described which are designed to help learning disabled (LD) students learn to perform computations in story problems. Activities proceed from concrete objects to numbers and involve the students in devising story problems. The language experience approach is incorporated with the enactive, iconic, and symbolic levels of…

Qualitative analysis of factors that increase and reduce involvement in gambling

Directory of Open Access Journals (Sweden)

Egidijus

2015-12-01

Full Text Available During the rapid development of gambling business, the number of pathological gamblers is increasing as well. The problem of pathological gambling is just as important as alcoholism or drug addiction. However, there is a lack of information and research of this topicin Lithuania. The aim of work: to investigate and analyse the factors that increase or reduce involvement in gambling. Research questions: 1 What factors increase involvement in gambling? 2 What factors reduce involvement in gambling? Critical case sampling was used for selection of the participants. Subjects were required to a have experience of involvement in gambling for at least one year; b have experience of negative impact of gambling on quality of life; c have at least 6 months of gambling abstinence. Five individuals participated in the research; all of them were males who live in Vilnius. Age of the participants varied from 19 to 45. Semi-structured interviews were used to collect data. Interviews were recorded and transcribed verbatim. The matic analysis of the data led to the identification of four major the matic categories: psychological factors; social relations; material well being; quality of life. There search results show that negatyve childhood experience, gambling friends, escaping from various troubles, disputes in family and high financial needs can increase involvement in gambling. Factors that reduce involvement in gambling are: feeling support of social environment, proper evaluation of financial position, awareness of one‘s own addiction to gambling and desire to change life.

Violence, victimization, criminal justice involvement, and substance use among drug-involved men.

Science.gov (United States)

Golder, Seana; Logan, T K

2014-01-01

This research identified three subgroups of drug-involved men based on severity of self-reported violence perpetration against intimate or nonintimate partners among a sample of 148 men selected from a subsample of participants in the Kentucky National Institute on Drug Abuse (NIDA) AIDS Cooperative Agreement. Men in the No Violence group accounted for approximately 19% of the total respondents, men in the Moderate Violence Severity and Extreme Violence Severity groups comprises 56% and 25% of the sample, respectively. Men in the Extreme Violence Severity group experienced significantly more psychological victimization as children and more frequent physical childhood abuse than did their peers. Men in the Extreme Violence Severity group reported having earlier involvement in the criminal justice system and lawbreaking behavior; they also reported higher frequency of marijuana and crack use. Implications for treatment and future research are presented.

The Importance of Patient Involvement in Stroke Rehabilitation

Science.gov (United States)

2016-01-01

Objective To investigate the perceived needs for health services by persons with stroke within the first year after rehabilitation, and associations between perceived impact of stroke, involvement in decisions regarding care/treatment, and having health services needs met. Method Data was collected, through a mail survey, from patients with stroke who were admitted to a university hospital in 2012 and had received rehabilitation after discharge from the stroke unit. The rehabilitation lasted an average of 2 to 4.6 months. The Stroke Survivor Needs Survey Questionnaire was used to assess the participants' perceptions of involvement in decisions on care or treatment and needs for health services in 11 problem areas: mobility, falls, incontinence, pain, fatigue, emotion, concentration, memory, speaking, reading, and sight. The perceived impact of stroke in eight areas was assessed using the Stroke Impact Scale (SIS) 3.0. Eleven logistic regression models were created to explore associations between having health services needs met in each problem area respectively (dependent variable) and the independent variables. In all models the independent variables were: age, sex, SIS domain corresponding to the dependent variable, or stroke severity in cases when no corresponding SIS domain was identified, and involvement in decisions on care and treatment. Results The 63 participants who returned the questionnaires had a mean age of 72 years, 33 were male and 30 were female. Eighty percent had suffered a mild stroke. The number of participants who reported problems varied between 51 (80%, mobility) and 24 (38%, sight). Involvement in decisions on care and treatment was found to be associated with having health services needs met in six problem areas: falls, fatigue, emotion, memory, speaking, and reading. Conclusions The results highlight the importance of involving patients in making decisions on stroke rehabilitation, as it appears to be associated with meeting their health

The Impact of Gender and Family Processes on Mental Health and Substance Use Issues in a Sample of Court-Involved Female and Male Adolescents

Science.gov (United States)

Gavazzi, Stephen M.; Lim, Ji-Young; Yarcheck, Courtney M.; Bostic, Jennifer M.; Scheer, Scott D.

2008-01-01

Greater empirical attention directed toward gender-sensitive assessment strategies that concentrate on family-specific factors is thought to be both timely and necessary, especially with regard to outcome variables associated with mental health and substance abuse in at-risk adolescent populations. A sample of 2,646 court-involved adolescents was…

Manage Your Life Online (MYLO): a pilot trial of a conversational computer-based intervention for problem solving in a student sample.

Science.gov (United States)

Gaffney, Hannah; Mansell, Warren; Edwards, Rachel; Wright, Jason

2014-11-01

Computerized self-help that has an interactive, conversational format holds several advantages, such as flexibility across presenting problems and ease of use. We designed a new program called MYLO that utilizes the principles of METHOD of Levels (MOL) therapy--based upon Perceptual Control Theory (PCT). We tested the efficacy of MYLO, tested whether the psychological change mechanisms described by PCT mediated its efficacy, and evaluated effects of client expectancy. Forty-eight student participants were randomly assigned to MYLO or a comparison program ELIZA. Participants discussed a problem they were currently experiencing with their assigned program and completed measures of distress, resolution and expectancy preintervention, postintervention and at 2-week follow-up. MYLO and ELIZA were associated with reductions in distress, depression, anxiety and stress. MYLO was considered more helpful and led to greater problem resolution. The psychological change processes predicted higher ratings of MYLO's helpfulness and reductions in distress. Positive expectancies towards computer-based problem solving correlated with MYLO's perceived helpfulness and greater problem resolution, and this was partly mediated by the psychological change processes identified. The findings provide provisional support for the acceptability of the MYLO program in a non-clinical sample although its efficacy as an innovative computer-based aid to problem solving remains unclear. Nevertheless, the findings provide tentative early support for the mechanisms of psychological change identified within PCT and highlight the importance of client expectations on predicting engagement in computer-based self-help.

Psychological problems, self-esteem and body dissatisfaction in a sample of adolescents with brain lesions: A comparison with a control group.

Science.gov (United States)

Pastore, Valentina; Colombo, Katia; Maestroni, Deborah; Galbiati, Susanna; Villa, Federica; Recla, Monica; Locatelli, Federica; Strazzer, Sandra

2015-01-01

This study aims to describe psychological problems, self-esteem difficulties and body dissatisfaction in a sample of adolescents with acquired brain lesions and to compare them with an age- and gender-matched control group. In an experimental design, the psychological profile of 26 adolescents with brain lesions of traumatic or vascular aetiology, aged 12-18 years, was compared with that of 18 typically-developing subjects. Moreover, within the clinical group, patients with TBI were compared with patients with vascular lesions. The psychological and adaptive profile of the adolescents was assessed by a specific protocol, including CBCL, VABS, RSES, EDI-2 and BES. Adolescents with brain lesions showed more marked psychological problems than their healthy peers; they also presented with a greater impairment of adaptive skills and a lower self-esteem. No significant differences were found between patients with traumatic lesions and patients with vascular lesions. Adolescents with acquired brain lesions were at higher risk to develop psychological and behavioural difficulties. Furthermore, in the clinical sample, some variables such as the long hospitalization and isolation from family and peers were associated to a greater psychological burden than the aetiology of the brain damage.

Astronauts' menu problem.

Science.gov (United States)

Lesso, W. G.; Kenyon, E.

1972-01-01

Consideration of the problems involved in choosing appropriate menus for astronauts carrying out SKYLAB missions lasting up to eight weeks. The problem of planning balanced menus on the basis of prepackaged food items within limitations on the intake of calories, protein, and certain elements is noted, as well as a number of other restrictions of both physical and arbitrary nature. The tailoring of a set of menus for each astronaut on the basis of subjective rankings of each food by the astronaut in terms of a 'measure of pleasure' is described, and a computer solution to this problem by means of a mixed integer programming code is presented.

A twin study exploring the association between childhood emotional and behaviour problems and specific psychotic experiences in a community sample of adolescents.

Science.gov (United States)

Shakoor, Sania; McGuire, Philip; Cardno, Alastair G; Freeman, Daniel; Ronald, Angelica

2018-05-01

Childhood emotional and behaviour problems are antecedents for later psychopathology. This study investigated genetic and environmental influences shaping the longitudinal association between childhood emotional and behaviour problems and specific PEs. In a community-based twin sample, parents reported on emotional and behaviour problems when twins were ages 7 and 12 years. At age 16 years, specific PEs were measured using self-reports and parent reports. Structural equation model-fitting was conducted. Childhood emotional and behaviour problems were significantly associated with paranoia, cognitive disorganisation and parent-rated negative symptoms in adolescence (mean r = .15-.38), and to a lesser extent with hallucinations, grandiosity and anhedonia (mean r = .04-.12). Genetic influences on childhood emotional and behaviour problems explained significant proportions of variance in adolescent paranoia (4%), cognitive disorganisation (8%) and parent-rated negative symptoms (3%). Unique environmental influences on childhood emotional and behaviour problems explained ≤1% of variance in PEs. Common environmental influences were only relevant for the relationship between childhood emotional and behaviour problems and parent-rated negative symptoms (explaining 28% of variance) and are partly due to correlated rater effects. Childhood emotional and behaviour problems are significantly, if weakly, associated with adolescent PEs. These associations are driven in part by common genetic influences underlying both emotional and behaviour problems and PEs. However, psychotic experiences in adolescence are largely influenced by genetic and environmental factors that are independent of general childhood emotional and behaviour problems, suggesting they are not merely an extension of childhood emotional and behaviour problems. © 2017 The Authors. Journal of Child Psychology and Psychiatry published by John Wiley & Sons Ltd on behalf of Association for Child and

The Role of Father Involvement in Children's Later Mental Health.

Science.gov (United States)

Flouri, Eirini; Buchanan, Ann

2003-01-01

Explores links between father involvement at age 7 and emotional and behavioral problems at age 16, and between father involvement at age 16 and psychological distress at age 33. Father involvement at age 7 protected against psychological maladjustment in adolescents from non-intact families, and father involvement at age 16 protected against…

Association between school bullying levels/types and mental health problems among Taiwanese adolescents.

Science.gov (United States)

Yen, Cheng-Fang; Yang, Pinchen; Wang, Peng-Wei; Lin, Huang-Chi; Liu, Tai-Ling; Wu, Yu-Yu; Tang, Tze-Chun

2014-04-01

Few studies have compared the risks of mental health problems among the adolescents with different levels and different types of bullying involvement experiences. Bullying involvement in 6,406 adolescents was determined through use of the Chinese version of the School Bullying Experience Questionnaire. Data were collected regarding the mental health problems, including depression, suicidality, insomnia, general anxiety, social phobia, alcohol abuse, inattention, and hyperactivity/impulsivity. The association between experiences of bullying involvement and mental health problems was examined. The risk of mental health problems was compared among those with different levels/types of bullying involvement. The results found that being a victim of any type of bullying and being a perpetrator of passive bullying were significantly associated with all kinds of mental health problems, and being a perpetrator of active bullying was significantly associated with all kinds of mental health problems except for general anxiety. Victims or perpetrators of both passive and active bullying had a greater risk of some dimensions of mental health problems than those involved in only passive or active bullying. Differences in the risk of mental health problems were also found among adolescents involved in different types of bullying. This difference in comorbid mental health problems should be taken into consideration when assessing adolescents involved in different levels/types of bullying. © 2014.

Teknik Sampling Snowball dalam Penelitian Lapangan

OpenAIRE

Nina Nurdiani

2014-01-01

Field research can be associated with both qualitative and quantitative research methods, depending on the problems faced and the goals to be achieved. The success of data collection in the field research depends on the determination of the appropriate sampling technique, to obtain accurate data, and reliably. In studies that have problems related to specific issues, requiring a non-probability sampling techniques one of which is the snowball sampling technique. This technique is useful for f...

Adolescents’ Problem Behaviors and Parent-Adolescent Conflicts in Hmong Immigrant Families

Directory of Open Access Journals (Sweden)

Zha Blong Xiong

2009-01-01

Full Text Available The purpose of the study was to investigate whether Hmong adolescent problem behaviors and school difficulties influence parent-adolescent conflicts above and beyond the variables of adolescents’ embarrassment about their parents, the acculturation gap between parents and adolescents, and age of adolescents. The sample included 209 Hmong adolescents living in Minnesota. There were 123 males and 86 females, ages 12 to 25 years. A survey was administered in several community agencies to adolescents that included their perspectives on the frequency and intensity of parent-adolescent disagreements on 28 issues and the problem behaviors of delinquent peer affiliation, gang involvement, truancy, and school performance. Results of hierarchical multiple regression analyses indicated the set of problem-behavior independent variables explained 26% of the variance in the frequency-intensity of father-adolescent conflicts and 21% of the variance in the frequency-intensity of mother-adolescent conflicts. Ideas for parent education in the Hmong community are discussed.

Traditional bullying and cyberbullying: Differences in emotional problems, and personality. Are cyberbullies more Machiavellians?

Science.gov (United States)

Resett, Santiago; Gamez-Guadix, Manuel

2017-12-01

Few studies have examined differences in emotional problems and personality of traditional bullies and cyberbullies. The present study aimed to determine whether those engaged in cyberbullying differ in emotional problems, and personality from those engage in traditional bullying perpetration. An Argentinean sample of 898 high school students was recruited (56% female; mean age = 15.2 SD = 1.6). Adolescents completed measures of traditional bullying, cyberbullying, self-esteem, anxiety, depression, and personality. A 6% were traditional bullies; 8%, cyberbullies; and 4% were involved in both forms; the remainders were non involved. Results indicated that cyberbullies showed less depression and anxiety than traditional bullies. Also, cyberbullies scored low in neuroticism and high in agreeableness compared to traditional bullies. The results suggest that cyberbullies are characterized by an emotional and personality profile different from traditional bullies. In the discussion we analyze the implications of these results. Copyright © 2017 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

The augmented lagrange multipliers method for matrix completion from corrupted samplings with application to mixed Gaussian-impulse noise removal.

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Fan Meng

Full Text Available This paper studies the problem of the restoration of images corrupted by mixed Gaussian-impulse noise. In recent years, low-rank matrix reconstruction has become a research hotspot in many scientific and engineering domains such as machine learning, image processing, computer vision and bioinformatics, which mainly involves the problem of matrix completion and robust principal component analysis, namely recovering a low-rank matrix from an incomplete but accurate sampling subset of its entries and from an observed data matrix with an unknown fraction of its entries being arbitrarily corrupted, respectively. Inspired by these ideas, we consider the problem of recovering a low-rank matrix from an incomplete sampling subset of its entries with an unknown fraction of the samplings contaminated by arbitrary errors, which is defined as the problem of matrix completion from corrupted samplings and modeled as a convex optimization problem that minimizes a combination of the nuclear norm and the l(1-norm in this paper. Meanwhile, we put forward a novel and effective algorithm called augmented Lagrange multipliers to exactly solve the problem. For mixed Gaussian-impulse noise removal, we regard it as the problem of matrix completion from corrupted samplings, and restore the noisy image following an impulse-detecting procedure. Compared with some existing methods for mixed noise removal, the recovery quality performance of our method is dominant if images possess low-rank features such as geometrically regular textures and similar structured contents; especially when the density of impulse noise is relatively high and the variance of Gaussian noise is small, our method can outperform the traditional methods significantly not only in the simultaneous removal of Gaussian noise and impulse noise, and the restoration ability for a low-rank image matrix, but also in the preservation of textures and details in the image.

Statistical distribution sampling

Science.gov (United States)

Johnson, E. S.

1975-01-01

Determining the distribution of statistics by sampling was investigated. Characteristic functions, the quadratic regression problem, and the differential equations for the characteristic functions are analyzed.

A Cognitive Model for Problem Solving in Computer Science

Science.gov (United States)

Parham, Jennifer R.

2009-01-01

According to industry representatives, computer science education needs to emphasize the processes involved in solving computing problems rather than their solutions. Most of the current assessment tools used by universities and computer science departments analyze student answers to problems rather than investigating the processes involved in…

Characterizing the Fundamental Intellectual Steps Required in the Solution of Conceptual Problems

Science.gov (United States)

Stewart, John

2010-02-01

At some level, the performance of a science class must depend on what is taught, the information content of the materials and assignments of the course. The introductory calculus-based electricity and magnetism class at the University of Arkansas is examined using a catalog of the basic reasoning steps involved in the solution of problems assigned in the class. This catalog was developed by sampling popular physics textbooks for conceptual problems. The solution to each conceptual problem was decomposed into its fundamental reasoning steps. These fundamental steps are, then, used to quantify the distribution of conceptual content within the course. Using this characterization technique, an exceptionally detailed picture of the information flow and structure of the class can be produced. The intellectual structure of published conceptual inventories is compared with the information presented in the class and the dependence of conceptual performance on the details of coverage extracted. )

Gang Involvement and Membership among Homeless and Runaway Youth.

Science.gov (United States)

Yoder, Kevin A.; Whitbeck, Les B.; Hoyt, Dan R.

2003-01-01

Assessed the extent of gang involvement among homeless and runaway youth, comparing gang members, gang-involved youth (not members), and non-gang youth on several dimensions. Interview data indicated that 15.4 percent of the youth were gang members and 32.2 percent were involved in gangs. These youth reported more family problems and school…

Problems in equilibrium theory

CERN Document Server

Aliprantis, Charalambos D

1996-01-01

In studying General Equilibrium Theory the student must master first the theory and then apply it to solve problems. At the graduate level there is no book devoted exclusively to teaching problem solving. This book teaches for the first time the basic methods of proof and problem solving in General Equilibrium Theory. The problems cover the entire spectrum of difficulty; some are routine, some require a good grasp of the material involved, and some are exceptionally challenging. The book presents complete solutions to two hundred problems. In searching for the basic required techniques, the student will find a wealth of new material incorporated into the solutions. The student is challenged to produce solutions which are different from the ones presented in the book.

Measurement of highly active samples of ultrashort-lived radionuclides and its problems

International Nuclear Information System (INIS)

van der Baan, J.G.; Panek, K.J.

1985-01-01

The measurement of highly active eluates obtained from the generators for ultrashort-lived radionuclides poses several problems which are briefly discussed by using the example of the /sup 195m/Hg→/sup 195m/Au generator. For overcoming some of the problems, the construction of a multiple single-channel analyzer that allows high count rates, is described, as well as the counting technique applicable for highly active eluates

Trauma histories among justice-involved youth: findings from the National Child Traumatic Stress Network

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Carly B. Dierkhising

2013-07-01

Full Text Available Background: Up to 90% of justice-involved youth report exposure to some type of traumatic event. On average, 70% of youth meet criteria for a mental health disorder with approximately 30% of youth meeting criteria for post-traumatic stress disorder (PTSD. Justice-involved youth are also at risk for substance use and academic problems, and child welfare involvement. Yet, less is known about the details of their trauma histories, and associations among trauma details, mental health problems, and associated risk factors. Objective: This study describes detailed trauma histories, mental health problems, and associated risk factors (i.e., academic problems, substance/alcohol use, and concurrent child welfare involvement among adolescents with recent involvement in the juvenile justice system. Method: The National Child Traumatic Stress Network Core Data Set (NCTSN-CDS is used to address these aims, among which 658 adolescents report recent involvement in the juvenile justice system as indexed by being detained or under community supervision by the juvenile court. Results: Age of onset of trauma exposure was within the first 5 years of life for 62% of youth and approximately one-third of youth report exposure to multiple or co-occurring trauma types each year into adolescence. Mental health problems are prevalent with 23.6% of youth meeting criteria for PTSD, 66.1% in the clinical range for externalizing problems, and 45.5% in the clinical range for internalizing problems. Early age of onset of trauma exposure was differentially associated with mental health problems and related risk factors among males and females. Conclusions: The results indicate that justice-involved youth report high rates of trauma exposure and that this trauma typically begins early in life, is often in multiple contexts, and persists over time. Findings provide support for establishing trauma-informed juvenile justice systems that can respond to the needs of traumatized youth.

Ethics in research involving prisoners.

Science.gov (United States)

Pont, Jörg

2008-01-01

Research involving prisoners repeatedly went astray during the last century, culminating in the cruel medical experiments inside the Nazi concentration camps that gave rise to the Nuremberg Code. However, prisoners continued to become victims of scientific exploitation by the rapidly evolving biomedical research industry. The common roots of these abuses were the flawed philosophy that the needs of the society outweigh the needs of the individual and the researchers' view that prisoners are cheap, easy to motivate and stable research subjects. Prisoners are vulnerable to exploitation and abuse by research because their freedom for consent can easily be undermined, and because of learning disabilities, illiteracy and language barriers prevailing within prisoner populations. Therefore, penal laws of some countries supported by a number of internationally agreed documents prohibit research involving prisoners completely. However, prisoners must also be regarded as vulnerable to the specific health problems in prisons, e.g. transmissible diseases, mental disorders and suicide - problems that need to be addressed by research involving prisoners. Additionally, the participation of prisoner patients in research they directly can benefit from should be provided. Hence, it must be a common objective to find the right balance between protection from exploitation and access to research beneficial to prisoners.

Problem-based learning and radiology

International Nuclear Information System (INIS)

Thurley, P.; Dennick, R.

2008-01-01

The Royal College of Radiologists recently published documents setting out guidelines to improve the teaching of radiology to medical students. These included recommendations that clinicians who teach radiology should be aware of newer educational techniques, such as problem-based learning, and should be involved in the development of curricula and assessment in medical schools. This review aims to introduce the educational theories behind problem-based learning and describe how a problem-based learning tutorial is run. The relevance of problem-based learning to radiology and the potential advantages and disadvantages are discussed

Reliability estimation system: its application to the nuclear geophysical sampling of ore deposits

International Nuclear Information System (INIS)

Khaykovich, I.M.; Savosin, S.I.

1992-01-01

The reliability estimation system accepted in the Soviet Union for sampling data in nuclear geophysics is based on unique requirements in metrology and methodology. It involves estimating characteristic errors in calibration, as well as errors in measurement and interpretation. This paper describes the methods of estimating the levels of systematic and random errors at each stage of the problem. The data of nuclear geophysics sampling are considered to be reliable if there are no statistically significant, systematic differences between ore intervals determined by this method and by geological control, or by other methods of sampling; the reliability of the latter having been verified. The difference between the random errors is statistically insignificant. The system allows one to obtain information on the parameters of ore intervals with a guaranteed random error and without systematic errors. (Author)

Gambling problems in the family – A stratified probability sample study of prevalence and reported consequences

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Øren Anita

2008-12-01

Full Text Available Abstract Background Prior studies on the impact of problem gambling in the family mainly include help-seeking populations with small numbers of participants. The objective of the present stratified probability sample study was to explore the epidemiology of problem gambling in the family in the general population. Methods Men and women 16–74 years-old randomly selected from the Norwegian national population database received an invitation to participate in this postal questionnaire study. The response rate was 36.1% (3,483/9,638. Given the lack of validated criteria, two survey questions ("Have you ever noticed that a close relative spent more and more money on gambling?" and "Have you ever experienced that a close relative lied to you about how much he/she gambles?" were extrapolated from the Lie/Bet Screen for pathological gambling. Respondents answering "yes" to both questions were defined as Concerned Significant Others (CSOs. Results Overall, 2.0% of the study population was defined as CSOs. Young age, female gender, and divorced marital status were factors positively associated with being a CSO. CSOs often reported to have experienced conflicts in the family related to gambling, worsening of the family's financial situation, and impaired mental and physical health. Conclusion Problematic gambling behaviour not only affects the gambling individual but also has a strong impact on the quality of life of family members.

The influence of personality traits and emotional and behavioral problems on repetitive nonsuicidal self-injury in a school sample.

Science.gov (United States)

Lüdtke, Janine; Weizenegger, Benedict; Rauber, Rachel; Contin, Brigitte; In-Albon, Tina; Schmid, Marc

2017-04-01

Nonsuicidal self-injury (NSSI) is highly prevalent among adolescents and associated with various mental health problems and suicidality. Previous studies have found that certain personality traits are related to NSSI behavior, however only few studies examined personality traits in adolescents with NSSI. Our study aimed to assess the relationship between personality traits and emotional and behavioral problems in predicting repetitive NSSI among adolescents from a school sample. Four hundred and forty-seven students (M=14.95years, SD=0.74, 52% male) completed self-report measures on NSSI, personality traits, and emotional and behavioral problems. The past year prevalence of occasional and repetitive NSSI was 4.9% and 6.3% respectively. Repetitive NSSI was significantly associated with female gender, higher levels of age, novelty seeking, harm avoidance, self-transcendence, antisocial behavior, and positive self and lower levels of persistence and self-directedness in univariate analyses. However, multivariate logistic regression analyses indicated that only high levels of antisocial behavior and low levels of self-directedness significantly predicted repetitive NSSI. The association between a lack of self-directedness and NSSI emphasizes the significance of targeting self-directedness in psychotherapy by strengthening self-awareness, affect tolerance and emotion regulation, as well as establishing and pursuing long-term goals. Copyright © 2017 Elsevier Inc. All rights reserved.

Computational methods and modeling. 1. Sampling a Position Uniformly in a Trilinear Hexahedral Volume

International Nuclear Information System (INIS)

Urbatsch, Todd J.; Evans, Thomas M.; Hughes, H. Grady

2001-01-01

Monte Carlo particle transport plays an important role in some multi-physics simulations. These simulations, which may additionally involve deterministic calculations, typically use a hexahedral or tetrahedral mesh. Trilinear hexahedrons are attractive for physics calculations because faces between cells are uniquely defined, distance-to-boundary calculations are deterministic, and hexahedral meshes tend to require fewer cells than tetrahedral meshes. We discuss one aspect of Monte Carlo transport: sampling a position in a tri-linear hexahedron, which is made up of eight control points, or nodes, and six bilinear faces, where each face is defined by four non-coplanar nodes in three-dimensional Cartesian space. We derive, code, and verify the exact sampling method and propose an approximation to it. Our proposed approximate method uses about one-third the memory and can be twice as fast as the exact sampling method, but we find that its inaccuracy limits its use to well-behaved hexahedrons. Daunted by the expense of the exact method, we propose an alternate approximate sampling method. First, calculate beforehand an approximate volume for each corner of the hexahedron by taking one-eighth of the volume of an imaginary parallelepiped defined by the corner node and the three nodes to which it is directly connected. For the sampling, assume separability in the parameters, and sample each parameter, in turn, from a linear pdf defined by the sum of the four corner volumes at each limit (-1 and 1) of the parameter. This method ignores the quadratic portion of the pdf, but it requires less storage, has simpler sampling, and needs no extra, on-the-fly calculations. We simplify verification by designing tests that consist of one or more cells that entirely fill a unit cube. Uniformly sampling complicated cells that fill a unit cube will result in uniformly sampling the unit cube. Unit cubes are easily analyzed. The first problem has four wedges (or tents, or A frames) whose

On Invertible Sampling and Adaptive Security

DEFF Research Database (Denmark)

Ishai, Yuval; Kumarasubramanian, Abishek; Orlandi, Claudio

2011-01-01

functionalities was left open. We provide the first convincing evidence that the answer to this question is negative, namely that some (randomized) functionalities cannot be realized with adaptive security. We obtain this result by studying the following related invertible sampling problem: given an efficient...... sampling algorithm A, obtain another sampling algorithm B such that the output of B is computationally indistinguishable from the output of A, but B can be efficiently inverted (even if A cannot). This invertible sampling problem is independently motivated by other cryptographic applications. We show......, under strong but well studied assumptions, that there exist efficient sampling algorithms A for which invertible sampling as above is impossible. At the same time, we show that a general feasibility result for adaptively secure MPC implies that invertible sampling is possible for every A, thereby...

Teknik Sampling Snowball dalam Penelitian Lapangan

Directory of Open Access Journals (Sweden)

Nina Nurdiani

2014-12-01

Full Text Available Field research can be associated with both qualitative and quantitative research methods, depending on the problems faced and the goals to be achieved. The success of data collection in the field research depends on the determination of the appropriate sampling technique, to obtain accurate data, and reliably. In studies that have problems related to specific issues, requiring a non-probability sampling techniques one of which is the snowball sampling technique. This technique is useful for finding, identifying, selecting and taking samples in a network or chain of relationships. Phased implementation procedures performed through interviews and questionnaires. Snowball sampling technique has strengths and weaknesses in its application. Field research housing sector become the case study to explain this sampling technique.

Block Model Approach in Problem Solving: Effects on Problem Solving Performance of the Grade V Pupils in Mathematics

Science.gov (United States)

de Guzman, Niño Jose P.; Belecina, Rene R.

2012-01-01

The teaching of mathematics involves problem solving skills which prove to be difficult on the part of the pupils due to misrepresentation of the word problems. Oftentimes, pupils tend to represent the phrase "more than" as addition and the word difference as "- ". This paper aims to address the problem solving skills of grade…

Inverse problems for Maxwell's equations

CERN Document Server

Romanov, V G

1994-01-01

The Inverse and Ill-Posed Problems Series is a series of monographs publishing postgraduate level information on inverse and ill-posed problems for an international readership of professional scientists and researchers. The series aims to publish works which involve both theory and applications in, e.g., physics, medicine, geophysics, acoustics, electrodynamics, tomography, and ecology.

Microfabricated Devices for Sample Extraction, Concentrations, and Related Sample Processing Technologies

Energy Technology Data Exchange (ETDEWEB)

Chen, Gang; Lin, Yuehe

2006-12-01

This is an invited book chapter. As with other analytical techniques, sample pretreatments, sample extraction, sample introduction, and related techniques are of extreme importance for micro-electro-mechanical systems (MEMS). Bio-MEMS devices and systems start with a sampling step. The biological sample then usually undergoes some kinds of sample preparation steps before the actual analysis. These steps may involve extracting the target sample from its matrix, removing interferences from the sample, derivatizing the sample to detectable species, or performing a sample preconcentration step. The integration of the components for sample pretreatment into microfluidic devices represents one of the remaining the bottle-neck towards achieving true miniaturized total analysis systems (?TAS). This chapter provides a thorough state-of-art of the developments in this field to date.

Multi-choice stochastic transportation problem involving general form of distributions.

Science.gov (United States)

Quddoos, Abdul; Ull Hasan, Md Gulzar; Khalid, Mohammad Masood

2014-01-01

Many authors have presented studies of multi-choice stochastic transportation problem (MCSTP) where availability and demand parameters follow a particular probability distribution (such as exponential, weibull, cauchy or extreme value). In this paper an MCSTP is considered where availability and demand parameters follow general form of distribution and a generalized equivalent deterministic model (GMCSTP) of MCSTP is obtained. It is also shown that all previous models obtained by different authors can be deduced with the help of GMCSTP. MCSTP with pareto, power function or burr-XII distributions are also considered and equivalent deterministic models are obtained. To illustrate the proposed model two numerical examples are presented and solved using LINGO 13.0 software package.

Mutation screening of AURKB and SYCP3 in patients with reproductive problems.

Science.gov (United States)

López-Carrasco, A; Oltra, S; Monfort, S; Mayo, S; Roselló, M; Martínez, F; Orellana, C

2013-02-01

Mutations in the spindle checkpoint genes can cause improper chromosome segregations and aneuploidies, which in turn may lead to reproductive problems. Two of the proteins involved in this checkpoint are Aurora kinase B (AURKB), preventing the anaphase whenever microtubule-kinetochore attachments are not the proper ones during metaphase; and synaptonemal complex protein 3 (SYCP3), which is essential for the formation of the complex and for the recombination of the homologous chromosomes. This study has attempted to clarify the possible involvement of both proteins in the reproductive problems of patients with chromosomal instability. In order to do this, we have performed a screening for genetic variants in AURKB and SYCP3 among these patients using Sanger sequencing. Only one apparently non-pathogenic deletion was found in SYCP3. On the other hand, we found six sequence variations in AURKB. The consequences of these changes on the protein were studied in silico using different bioinformatic tools. In addition, the frequency of three of the variations was studied using a high-resolution melting approach. The absence of these three variants in control samples and their position in the AURKB gene suggests their possible involvement in the patients' chromosomal instability. Interestingly, two of the identified changes in AURKB were found in each member of a couple with antecedents of spontaneous pregnancy loss, a fetal anencephaly and a deaf daughter. One of these changes is described here for the first time. Although further studies are necessary, our results are encouraging enough to propose the analysis of AURKB in couples with reproductive problems.

Partial coherence with application to the monotonicity problem of coherence involving skew information

Science.gov (United States)

Luo, Shunlong; Sun, Yuan

2017-08-01

Quantifications of coherence are intensively studied in the context of completely decoherent operations (i.e., von Neuamnn measurements, or equivalently, orthonormal bases) in recent years. Here we investigate partial coherence (i.e., coherence in the context of partially decoherent operations such as Lüders measurements). A bona fide measure of partial coherence is introduced. As an application, we address the monotonicity problem of K -coherence (a quantifier for coherence in terms of Wigner-Yanase skew information) [Girolami, Phys. Rev. Lett. 113, 170401 (2014), 10.1103/PhysRevLett.113.170401], which is introduced to realize a measure of coherence as axiomatized by Baumgratz, Cramer, and Plenio [Phys. Rev. Lett. 113, 140401 (2014), 10.1103/PhysRevLett.113.140401]. Since K -coherence fails to meet the necessary requirement of monotonicity under incoherent operations, it is desirable to remedy this monotonicity problem. We show that if we modify the original measure by taking skew information with respect to the spectral decomposition of an observable, rather than the observable itself, as a measure of coherence, then the problem disappears, and the resultant coherence measure satisfies the monotonicity. Some concrete examples are discussed and related open issues are indicated.

Cerebral Palsy: Still A Social Problem

Directory of Open Access Journals (Sweden)

Angom Bisharda

1997-08-01

Full Text Available Research Problem: What arc the social aspects of cerebral palsy?Objective: To determine the extent and severity of neuromuscular involvement in cases of cerebral palsy and to find out the associated defects among these children.Study Design: Cross sectional study.Setting: Tertiary care hospital, outdoor patients.Participants: Children in the age group of 0 - 12 years.Sample Size: 120 children suffering from cerebral palsy.Study Variables: Social factors, neuromuscular involvement.Statistical Analysis: By proportionsResult: Out of 120 cases, maximum number of cases (66.6% were in the age group of 1- 4 years. 83 cases ( 69.16% were males. Among the various types, spastic type was the commonest (87.5%. Of these spastic cases, 52 (49.52% had quadriplegia. No case of tremor and rigidity was seen. Delayed milestones was the commonest associated disorder, seen in 107 (89.16% cases, followed by speech defect in 58(48.3% cases, visual defect in 34(28.3% cases and convulsions in 24 (20.0% cases. Hearing defect was seen in 5 cases (4.16% only.Conclusion: More concerted efforts arc required to identify children with cerebral palsy and rehabilitate them for the betterment of society.

Cerebral Palsy: Still A Social Problem

Directory of Open Access Journals (Sweden)

Angom Bisharda

1997-08-01

Full Text Available Research Problem: What arc the social aspects of cerebral palsy? Objective: To determine the extent and severity of neuromuscular involvement in cases of cerebral palsy and to find out the associated defects among these children. Study Design: Cross sectional study. Setting: Tertiary care hospital, outdoor patients. Participants: Children in the age group of 0 - 12 years. Sample Size: 120 children suffering from cerebral palsy. Study Variables: Social factors, neuromuscular involvement. Statistical Analysis: By proportions Result: Out of 120 cases, maximum number of cases (66.6% were in the age group of 1- 4 years. 83 cases ( 69.16% were males. Among the various types, spastic type was the commonest (87.5%. Of these spastic cases, 52 (49.52% had quadriplegia. No case of tremor and rigidity was seen. Delayed milestones was the commonest associated disorder, seen in 107 (89.16% cases, followed by speech defect in 58(48.3% cases, visual defect in 34(28.3% cases and convulsions in 24 (20.0% cases. Hearing defect was seen in 5 cases (4.16% only. Conclusion: More concerted efforts arc required to identify children with cerebral palsy and rehabilitate them for the betterment of society.

Least-squares methods involving the H{sup -1} inner product

Energy Technology Data Exchange (ETDEWEB)

Pasciak, J.

1996-12-31

Least-squares methods are being shown to be an effective technique for the solution of elliptic boundary value problems. However, the methods differ depending on the norms in which they are formulated. For certain problems, it is much more natural to consider least-squares functionals involving the H{sup -1} norm. Such norms give rise to improved convergence estimates and better approximation to problems with low regularity solutions. In addition, fewer new variables need to be added and less stringent boundary conditions need to be imposed. In this talk, I will describe some recent developments involving least-squares methods utilizing the H{sup -1} inner product.

Monte Carlo parametric importance sampling with particle tracks scaling

International Nuclear Information System (INIS)

Ragheb, M.M.H.

1981-01-01

A method for Monte Carlo importance sampling with parametric dependence is proposed. It depends upon obtaining over a single stage the overall functional dependence of the variance on the importance function parameter over a broad range of its values. Results corresponding to minimum variance are adopted and others rejected. The proposed method is applied to the finite slab penetration problem. When the exponential transformation is used, our method involves scaling of the generated particle tracks, and is a new application of Morton's method of similar trajectories. The method constitutes a generalization of Spanier's multistage importance sampling method, obtained by proper weighting over a single stage the curves he obtains over several stages, and preserves the statistical correlations between histories. It represents an extension of a theory by Frolov and Chentsov on Monte Carlo calculations of smooth curves to surfaces and to importance sampling calculations. By the proposed method, it seems possible to systematically arrive at minimum variance results and to avoid the infinite variances and effective biases sometimes observed in this type of calculation. (orig.) [de

Problem Gambling Among Ontario Students: Associations with Substance Abuse, Mental Health Problems, Suicide Attempts, and Delinquent Behaviours.

Science.gov (United States)

Cook, Steven; Turner, Nigel E; Ballon, Bruce; Paglia-Boak, Angela; Murray, Robert; Adlaf, Edward M; Ilie, Gabriela; den Dunnen, Wendy; Mann, Robert E

2015-12-01

This paper describes gambling problems among Ontario students in 2009 and examines the relationship between gambling problems and substance use problems, mental health problem indicators, and delinquent behaviors. Data were derived from the Ontario Student Drug Use and Health Survey of Ontario students in grades 7-12. Gambling problems were measured as 2 or more of 6 indicators of problem gambling. In total 2.8% of the students surveyed endorsed two or more of the problem gambling items. The odds of problem gamblers reporting mental distress was 4.2 times higher than the rest of the sample and the odds of problem gamblers reporting a suicide attempt were 17.8 times greater than the rest of the sample. In addition compared to the rest of the students, delinquent behaviors were also more common among problem gamblers, including theft (OR = 14.5), selling marijuana (OR = 19.6), gang fights (OR = 11.3) and carrying a handgun (OR = 11.2). In a multivariate analysis, substance-use problems, mental health problems, and the participation in a variety of delinquent behaviors remained significantly associated with youth problem gambling behavior. Students who report problem gambling behaviors show increased substance abuse, mental health, and delinquency/criminal problems that are similar to those seen among adult problem gamblers. The association between these problems suggests that these problems could be addressed in a unified manner.

Sodium sampling and impurities determination

International Nuclear Information System (INIS)

Docekal, J.; Kovar, C.; Stuchlik, S.

1980-01-01

Samples may be obtained from tubes in-built in the sodium facility and further processed or they are taken into crucibles, stored and processed later. Another sampling method is a method involving vacuum distillation of sodium, thus concentrating impurities. Oxygen is determined by malgamation, distillation or vanadium balance methods. Hydrogen is determined by the metal diaphragm extraction, direct extraction or amalgamation methods. Carbon is determined using dry techniques involving burning a sodium sample at 1100 degC or using wet techniques by dissolving the sample with an acid. Trace amounts of metal impurities are determined after dissolving sodium in ethanol. The trace metals are concentrated and sodium excess is removed. (M.S.)

Energy drink use, problem drinking and drinking motives in a diverse sample of Alaskan college students

Directory of Open Access Journals (Sweden)

Monica C. Skewes

2013-08-01

Full Text Available Background. Recent research has identified the use of caffeinated energy drinks as a common, potentially risky behaviour among college students that is linked to alcohol misuse and consequences. Research also suggests that energy drink consumption is related to other risky behaviours such as tobacco use, marijuana use and risky sexual activity. Objective. This research sought to examine the associations between frequency of energy drink consumption and problematic alcohol use, alcohol-related consequences, symptoms of alcohol dependence and drinking motives in an ethnically diverse sample of college students in Alaska. We also sought to examine whether ethnic group moderated these associations in the present sample of White, Alaska Native/American Indian and other ethnic minority college students. Design. A paper-and-pencil self-report questionnaire was completed by a sample of 298 college students. Analysis of covariance (ANCOVA was used to examine the effects of energy drink use, ethnic group and energy drink by ethnic group interactions on alcohol outcomes after controlling for variance attributed to gender, age and frequency of binge drinking. Results. Greater energy drink consumption was significantly associated with greater hazardous drinking, alcohol consequences, alcohol dependence symptoms, drinking for enhancement motives and drinking to cope. There were no main effects of ethnic group, and there were no significant energy drink by ethnic group interactions. Conclusion. These findings replicate those of other studies examining the associations between energy drink use and alcohol problems, but contrary to previous research we did not find ethnic minority status to be protective. It is possible that energy drink consumption may serve as a marker for other health risk behaviours among students of various ethnic groups.

Some remarks on the optimization of eigenvalue problems involving the p-Laplacian

Directory of Open Access Journals (Sweden)

Wacław Pielichowski

2008-01-01

Full Text Available Given a bounded domain \\(\\Omega \\subset \\mathbb{R}^n\\, numbers \\(p \\gt 1\\, \\(\\alpha \\geq 0\\ and \\(A \\in [0,|\\Omega |]\\, consider the optimization problem: find a subset \\(D \\subset \\Omega \\, of measure \\(A\\, for which the first eigenvalue of the operator \\(u\\mapsto -\\text{div} (|\

Analysis of mathematical problem-solving ability based on metacognition on problem-based learning

Science.gov (United States)

Mulyono; Hadiyanti, R.

2018-03-01

Problem-solving is the primary purpose of the mathematics curriculum. Problem-solving abilities influenced beliefs and metacognition. Metacognition as superordinate capabilities can direct, regulate cognition and motivation and then problem-solving processes. This study aims to (1) test and analyzes the quality of problem-based learning and (2) investigate the problem-solving capabilities based on metacognition. This research uses mixed method study with The subject research are class XI students of Mathematics and Science at High School Kesatrian 2 Semarang which divided into tacit use, aware use, strategic use and reflective use level. The collecting data using scale, interviews, and tests. The data processed with the proportion of test, t-test, and paired samples t-test. The result shows that the students with levels tacit use were able to complete the whole matter given, but do not understand what and why a strategy is used. Students with aware use level were able to solve the problem, be able to build new knowledge through problem-solving to the indicators, understand the problem, determine the strategies used, although not right. Students on the Strategic ladder Use can be applied and adopt a wide variety of appropriate strategies to solve the issues and achieved re-examine indicators of process and outcome. The student with reflective use level is not found in this study. Based on the results suggested that study about the identification of metacognition in problem-solving so that the characteristics of each level of metacognition more clearly in a more significant sampling. Teachers need to know in depth about the student metacognitive activity and its relationship with mathematical problem solving and another problem resolution.

Some "Real" Problems of "Virtual" Organisation.

Science.gov (United States)

Hughes, John A.; O'Brien, Jon; Randall, Dave; Rouncefield, Mark; Tolmie, Peter

2001-01-01

An ethnographic study of organizational change in a bank considered issues surrounding virtual teamwork in virtual organizations. Problems in communication, management control, and approach to customer service were found. An underlying cause is that "virtual" work involves "real" customers, workers, and problems. (Contains 36 references.) (SK)

Solving Environmental Problems

DEFF Research Database (Denmark)

Ørding Olsen, Anders; Sofka, Wolfgang; Grimpe, Christoph

2017-01-01

for Research and Technological Development (FP7), our results indicate that the problem-solving potential of a search strategy increases with the diversity of existing knowledge of the partners in a consortium and with the experience of the partners involved. Moreover, we identify a substantial negative effect...... dispersed. Hence, firms need to collaborate. We shed new light on collaborative search strategies led by firms in general and for solving environmental problems in particular. Both topics are largely absent in the extant open innovation literature. Using data from the European Seventh Framework Program...

Logarithmically completely monotonic functions involving the Generalized Gamma Function

OpenAIRE

Faton Merovci; Valmir Krasniqi

2010-01-01

By a simple approach, two classes of functions involving generalization Euler's gamma function and originating from certain  problems of traffic flow are proved to be logarithmically  completely monotonic and a class of functions involving the psi function is showed to be completely monotonic.

Maybe Small Is Too Small a Term: Introduction to Advancing Small Sample Prevention Science.

Science.gov (United States)

Fok, Carlotta Ching Ting; Henry, David; Allen, James

2015-10-01

Prevention research addressing health disparities often involves work with small population groups experiencing such disparities. The goals of this special section are to (1) address the question of what constitutes a small sample; (2) identify some of the key research design and analytic issues that arise in prevention research with small samples; (3) develop applied, problem-oriented, and methodologically innovative solutions to these design and analytic issues; and (4) evaluate the potential role of these innovative solutions in describing phenomena, testing theory, and evaluating interventions in prevention research. Through these efforts, we hope to promote broader application of these methodological innovations. We also seek whenever possible, to explore their implications in more general problems that appear in research with small samples but concern all areas of prevention research. This special section includes two sections. The first section aims to provide input for researchers at the design phase, while the second focuses on analysis. Each article describes an innovative solution to one or more challenges posed by the analysis of small samples, with special emphasis on testing for intervention effects in prevention research. A concluding article summarizes some of their broader implications, along with conclusions regarding future directions in research with small samples in prevention science. Finally, a commentary provides the perspective of the federal agencies that sponsored the conference that gave rise to this special section.

Test of the role of nicotine dependence in the relation between posttraumatic stress disorder and panic spectrum problems.

Science.gov (United States)

Feldner, Matthew T; Smith, Rose C; Babson, Kimberly A; Sachs-Ericsson, Natalie; Schmidt, Norman B; Zvolensky, Michael J

2009-02-01

Posttraumatic stress disorder (PTSD) frequently co-occurs with panic spectrum problems. Relatively little empirical work has tested possible mechanisms accounting for this association. Nicotine dependence often ensues subsequent to PTSD onset and research suggests smoking high numbers of cigarettes daily may lead to panic problems. The current study tested the hypotheses that nicotine dependence partially mediates the relations between PTSD and both panic attacks and panic disorder within a nationally representative sample of 5,692 (3,020 women; M(Age) = 45, SD = 18) adults from the National Comorbidity Survey-Replication. Results were consistent with hypotheses. These findings support the theory suggesting smoking among people with PTSD may be involved in the development of panic problems.

Word Problems: A "Meme" for Our Times.

Science.gov (United States)

Leamnson, Robert N.

1996-01-01

Discusses a novel approach to word problems that involves linear relationships between variables. Argues that working stepwise through intermediates is the way our minds actually work and therefore this should be used in solving word problems. (JRH)

40 CFR 1065.150 - Continuous sampling.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Continuous sampling. 1065.150 Section... ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.150 Continuous sampling. You may use continuous sampling techniques for measurements that involve raw or dilute sampling. Make sure continuous sampling...

DSMC multicomponent aerosol dynamics: Sampling algorithms and aerosol processes

Science.gov (United States)

Palaniswaamy, Geethpriya

The post-accident nuclear reactor primary and containment environments can be characterized by high temperatures and pressures, and fission products and nuclear aerosols. These aerosols evolve via natural transport processes as well as under the influence of engineered safety features. These aerosols can be hazardous and may pose risk to the public if released into the environment. Computations of their evolution, movement and distribution involve the study of various processes such as coagulation, deposition, condensation, etc., and are influenced by factors such as particle shape, charge, radioactivity and spatial inhomogeneity. These many factors make the numerical study of nuclear aerosol evolution computationally very complicated. The focus of this research is on the use of the Direct Simulation Monte Carlo (DSMC) technique to elucidate the role of various phenomena that influence the nuclear aerosol evolution. In this research, several aerosol processes such as coagulation, deposition, condensation, and source reinforcement are explored for a multi-component, aerosol dynamics problem in a spatially homogeneous medium. Among the various sampling algorithms explored the Metropolis sampling algorithm was found to be effective and fast. Several test problems and test cases are simulated using the DSMC technique. The DSMC results obtained are verified against the analytical and sectional results for appropriate test problems. Results show that the assumption of a single mean density is not appropriate due to the complicated effect of component densities on the aerosol processes. The methods developed and the insights gained will also be helpful in future research on the challenges associated with the description of fission product and aerosol releases.

Problem Patron Manual.

Science.gov (United States)

Brown, Marion, Comp.; And Others

This document presents guidelines for handling disruptive behavior in the Schenectady County Public Library (New York). Specific responses are listed for dealing with questions about library selection policy and sudden patron illness or injury. Also listed are responses to problem situations involving angry or irate patrons, assault or physically…

Statistical problems in the assessment of nuclear risks

International Nuclear Information System (INIS)

Easterling, R.G.

1980-01-01

Information on nuclear power plant risk assessment is presented concerning attitudinal problems; and methodological problems involving expert opinions, human error probabilities, nonindependent events, uncertainty analysis, and acceptable risk criteria

Analytical derivation: An epistemic game for solving mathematically based physics problems

Science.gov (United States)

Bajracharya, Rabindra R.; Thompson, John R.

2016-06-01

Problem solving, which often involves multiple steps, is an integral part of physics learning and teaching. Using the perspective of the epistemic game, we documented a specific game that is commonly pursued by students while solving mathematically based physics problems: the analytical derivation game. This game involves deriving an equation through symbolic manipulations and routine mathematical operations, usually without any physical interpretation of the processes. This game often creates cognitive obstacles in students, preventing them from using alternative resources or better approaches during problem solving. We conducted hour-long, semi-structured, individual interviews with fourteen introductory physics students. Students were asked to solve four "pseudophysics" problems containing algebraic and graphical representations. The problems required the application of the fundamental theorem of calculus (FTC), which is one of the most frequently used mathematical concepts in physics problem solving. We show that the analytical derivation game is necessary, but not sufficient, to solve mathematically based physics problems, specifically those involving graphical representations.

CHASM Challenge Problem: Lagrangian Hydrodynamics

Energy Technology Data Exchange (ETDEWEB)

Hornung, R [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Keasler, J [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gokhale, M [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2010-09-10

Computer simulations of many science and engineering problems require modeling the equations of hydrodynamics which describe the motion of materials relative to each other induced by various forces. Many important DoD simulation problems involve complex multi-material systems that undergo large deformations. Examples include the analysis of armor defense, penetration mechanics, blast effects, structural integrity, and conventional munitions such as shaped charges and explosively formed projectiles. Indeed, the original motivation for developing codes that solve the equations of hydrodynamics, herein referred to as “hydrocodes”, was to solve problems with defense applications. The FY2010 Requirements Analysis Report issued by the DoD High Performance Computing Modernization Program (HPCMP) Office shows that a major portion of DoD HPC activities involves hydrocodes [HPCMP2010]. The report surveyed 496 projects across the Services and various Agencies, representing 4,050 HPCMP users at more than 125 locations, including government, contractors, and academia, and grouped each project into one of ten categories.

Attributes Heeded When Representing an Osmosis Problem.

Science.gov (United States)

Zuckerman, June Trop

Eighteen high school science students were involved in a study to determine what attributes in the problem statement they need when representing a typical osmosis problem. In order to realize this goal students were asked to solve problems aloud and to explain their answers. Included as a part of the results are the attributes that the students…

[Ethical problems in organ transplantation].

Science.gov (United States)

Valenta, J; Treska, V; Hasman, D

1999-02-01

Organ transplantation is an accepted therapeutic method with good results, but it is connected with many not only medical but also ethical problems. One of the most important problems is the donor programme. In cadaverous donors the main ethical and legal question is the decision who can issue the consent with organ retrieval; in living donors it is the problem of motivation and financial compensation. Allocation of organs with low compatibility or from non-ideal donors, and the recipient's consent in these cases may involve difficult decisions.

Sampling from a system-theoretic viewpoint

NARCIS (Netherlands)

Meinsma, Gjerrit; Mirkin, Leonid

2009-01-01

This paper studies a system-theoretic approach to the problem of reconstructing an analog signal from its samples. The idea, borrowed from earlier treatments in the control literature, is to address the problem as a hybrid model-matching problem in which performance is measured by system norms. The

Sleep in a large, multi-university sample of college students: sleep problem prevalence, sex differences, and mental health correlates.

Science.gov (United States)

Becker, Stephen P; Jarrett, Matthew A; Luebbe, Aaron M; Garner, Annie A; Burns, G Leonard; Kofler, Michael J

2018-04-01

To (1) describe sleep problems in a large, multi-university sample of college students; (2) evaluate sex differences; and (3) examine the unique associations of mental health symptoms (i.e., anxiety, depression, attention-deficit/hyperactivity disorder inattention [ADHD-IN], ADHD hyperactivity-impulsivity [ADHD-HI]) in relation to sleep problems. 7,626 students (70% female; 81% White) ages 18-29 years (M=19.14, SD=1.42) from six universities completed measures assessing mental health symptoms and the Pittsburgh Sleep Quality Index (PSQI). A substantial minority of students endorsed sleep problems across specific sleep components. Specifically, 27% described their sleep quality as poor, 36% reported obtaining less than 7 hours of sleep per night, and 43% reported that it takes >30 minutes to fall asleep at least once per week. 62% of participants met cut-off criteria for poor sleep, though rates differed between females (64%) and males (57%). In structural regression models, both anxiety and depression symptoms were uniquely associated with disruptions in most PSQI sleep component domains. However, anxiety (but not depression) symptoms were uniquely associated with more sleep disturbances and sleep medication use, whereas depression (but not anxiety) symptoms were uniquely associated with increased daytime dysfunction. ADHD-IN symptoms were uniquely associated with poorer sleep quality and increased daytime dysfunction, whereas ADHD-HI symptoms were uniquely associated with more sleep disturbances and less daytime dysfunction. Lastly, ADHD-IN, anxiety, and depression symptoms were each independently associated with poor sleep status. This study documents a high prevalence of poor sleep among college students, some sex differences, and distinct patterns of mental health symptoms in relation to sleep problems. Copyright © 2018. Published by Elsevier Inc.

Creativity and Insight in Problem Solving

Science.gov (United States)

Golnabi, Laura

2016-01-01

This paper analyzes the thought process involved in problem solving and its categorization as creative thinking as defined by psychologist R. Weisberg (2006). Additionally, the notion of insight, sometimes present in unconscious creative thinking and often leading to creative ideas, is discussed in the context of geometry problem solving. In…

Waring's Problem and the Circle Method

Indian Academy of Sciences (India)

other interests include classical music and mountaineering. the problems they worked on. Their proof of a slightly. Keywords weaker form of Ramanujan's original formula was pub-. Waring's problem, circle method, ... arc is fairly simple while it is the minor arc estimation that accounts for the 'major' amount of work involved!

Case of two electrostatics problems: Can providing a diagram adversely impact introductory physics students’ problem solving performance?

Directory of Open Access Journals (Sweden)

Alexandru Maries

2018-03-01

Full Text Available Drawing appropriate diagrams is a useful problem solving heuristic that can transform a problem into a representation that is easier to exploit for solving it. One major focus while helping introductory physics students learn effective problem solving is to help them understand that drawing diagrams can facilitate problem solution. We conducted an investigation in which two different interventions were implemented during recitation quizzes in a large enrollment algebra-based introductory physics course. Students were either (i asked to solve problems in which the diagrams were drawn for them or (ii explicitly told to draw a diagram. A comparison group was not given any instruction regarding diagrams. We developed rubrics to score the problem solving performance of students in different intervention groups and investigated ten problems. We found that students who were provided diagrams never performed better and actually performed worse than the other students on three problems, one involving standing sound waves in a tube (discussed elsewhere and two problems in electricity which we focus on here. These two problems were the only problems in electricity that involved considerations of initial and final conditions, which may partly account for why students provided with diagrams performed significantly worse than students who were not provided with diagrams. In order to explore potential reasons for this finding, we conducted interviews with students and found that some students provided with diagrams may have spent less time on the conceptual analysis and planning stage of the problem solving process. In particular, those provided with the diagram were more likely to jump into the implementation stage of problem solving early without fully analyzing and understanding the problem, which can increase the likelihood of mistakes in solutions.

Case of two electrostatics problems: Can providing a diagram adversely impact introductory physics students' problem solving performance?

Science.gov (United States)

Maries, Alexandru; Singh, Chandralekha

2018-06-01

Drawing appropriate diagrams is a useful problem solving heuristic that can transform a problem into a representation that is easier to exploit for solving it. One major focus while helping introductory physics students learn effective problem solving is to help them understand that drawing diagrams can facilitate problem solution. We conducted an investigation in which two different interventions were implemented during recitation quizzes in a large enrollment algebra-based introductory physics course. Students were either (i) asked to solve problems in which the diagrams were drawn for them or (ii) explicitly told to draw a diagram. A comparison group was not given any instruction regarding diagrams. We developed rubrics to score the problem solving performance of students in different intervention groups and investigated ten problems. We found that students who were provided diagrams never performed better and actually performed worse than the other students on three problems, one involving standing sound waves in a tube (discussed elsewhere) and two problems in electricity which we focus on here. These two problems were the only problems in electricity that involved considerations of initial and final conditions, which may partly account for why students provided with diagrams performed significantly worse than students who were not provided with diagrams. In order to explore potential reasons for this finding, we conducted interviews with students and found that some students provided with diagrams may have spent less time on the conceptual analysis and planning stage of the problem solving process. In particular, those provided with the diagram were more likely to jump into the implementation stage of problem solving early without fully analyzing and understanding the problem, which can increase the likelihood of mistakes in solutions.

Neighborhood Qualification of the Association Between Parenting and Problem Behavior Trajectories Among Mexican-Origin Father-Adolescent Dyads.

Science.gov (United States)

White, Rebecca M B; Liu, Yu; Gonzales, Nancy A; Knight, George P; Tein, Jenn-Yun

2016-12-01

To address the combined importance of fathers and neighborhoods for adolescent adjustment, we examined whether associations between fathers' parenting and adolescents' problem behaviors were qualified by neighborhood adversity. We captured both mainstream (e.g., authoritative) and alternative (e.g., no-nonsense, reduced involvement) parenting styles and examined parenting and neighborhood effects on changes over time in problem behaviors among a sample of Mexican-origin father-adolescent dyads (N = 462). Compared to their counterparts in low-adversity neighborhoods, adolescents in high-adversity neighborhoods experienced greater initial benefits from authoritative fathering, greater long-term benefits from no-nonsense fathering, and fewer costs associated with reduced involvement fathering. The combined influences of alternative paternal parenting styles and neighborhood adversity may set ethnic and racial minority adolescents on different developmental pathways to competence. © 2016 The Authors. Journal of Research on Adolescence © 2016 Society for Research on Adolescence.

Logarithmically completely monotonic functions involving the Generalized Gamma Function

Directory of Open Access Journals (Sweden)

Faton Merovci

2010-12-01

Full Text Available By a simple approach, two classes of functions involving generalization Euler's gamma function and originating from certain  problems of traffic flow are proved to be logarithmically  completely monotonic and a class of functions involving the psi function is showed to be completely monotonic.

Computer-Based Communication and Cyberbullying Involvement in the Sample of Arab Teenagers

Science.gov (United States)

Heiman, Tali; Olenik-Shemesh, Dorit

2016-01-01

The use of the internet among teenagers has increased in recent years and nearly 92% of all teenagers in Israel surf the internet. This study examined the characteristics of involvement in cyberbullying among 114 adolescents in the Muslim Arab sector, and its relationships with emotional aspects. The students completed questionnaires regarding…

Stochastic Linear Quadratic Optimal Control Problems

International Nuclear Information System (INIS)

Chen, S.; Yong, J.

2001-01-01

This paper is concerned with the stochastic linear quadratic optimal control problem (LQ problem, for short) for which the coefficients are allowed to be random and the cost functional is allowed to have a negative weight on the square of the control variable. Some intrinsic relations among the LQ problem, the stochastic maximum principle, and the (linear) forward-backward stochastic differential equations are established. Some results involving Riccati equation are discussed as well

Expression profiling identifies genes involved in emphysema severity

Directory of Open Access Journals (Sweden)

Bowman Rayleen V

2009-09-01

Full Text Available Abstract Chronic obstructive pulmonary disease (COPD is a major public health problem. The aim of this study was to identify genes involved in emphysema severity in COPD patients. Gene expression profiling was performed on total RNA extracted from non-tumor lung tissue from 30 smokers with emphysema. Class comparison analysis based on gas transfer measurement was performed to identify differentially expressed genes. Genes were then selected for technical validation by quantitative reverse transcriptase-PCR (qRT-PCR if also represented on microarray platforms used in previously published emphysema studies. Genes technically validated advanced to tests of biological replication by qRT-PCR using an independent test set of 62 lung samples. Class comparison identified 98 differentially expressed genes (p p Gene expression profiling of lung from emphysema patients identified seven candidate genes associated with emphysema severity including COL6A3, SERPINF1, ZNHIT6, NEDD4, CDKN2A, NRN1 and GSTM3.

Discovering Steiner Triple Systems through Problem Solving

Science.gov (United States)

Sriraman, Bharath

2004-01-01

An attempt to implement problem solving as a teacher of ninth grade algebra is described. The problems selected were not general ones, they involved combinations and represented various situations and were more complex which lead to the discovery of Steiner triple systems.

Multifaceted Communication Problems in Everyday Conversations Involving People with Parkinson’s Disease

Directory of Open Access Journals (Sweden)

Charlotta Saldert

2017-09-01

Full Text Available It is known that Parkinson’s disease is often accompanied by a motor speech disorder, which results in impaired communication. However, people with Parkinson’s disease may also have impaired word retrieval (anomia and other communicative problems, which have a negative impact on their ability to participate in conversations with family as well as healthcare staff. The aim of the present study was to explore effects of impaired speech and language on communication and how this is managed by people with Parkinson’s disease and their spouses. Using a qualitative method based on Conversation Analysis, in-depth analyses were performed on natural conversational interaction in five dyads including elderly men who were at different stages of Parkinson’s disease. The findings showed that the motor speech disorder in combination with word retrieval difficulties and adaptations, such as using communication strategies, may result in atypical utterances that are difficult for communication partners to understand. The coexistence of several communication problems compounds the difficulties faced in conversations and individuals with Parkinson’s disease are often dependent on cooperation with their communication partner to make themselves understood.

Multifaceted Communication Problems in Everyday Conversations Involving People with Parkinson’s Disease

Science.gov (United States)

Saldert, Charlotta; Bauer, Malin

2017-01-01

It is known that Parkinson’s disease is often accompanied by a motor speech disorder, which results in impaired communication. However, people with Parkinson’s disease may also have impaired word retrieval (anomia) and other communicative problems, which have a negative impact on their ability to participate in conversations with family as well as healthcare staff. The aim of the present study was to explore effects of impaired speech and language on communication and how this is managed by people with Parkinson’s disease and their spouses. Using a qualitative method based on Conversation Analysis, in-depth analyses were performed on natural conversational interaction in five dyads including elderly men who were at different stages of Parkinson’s disease. The findings showed that the motor speech disorder in combination with word retrieval difficulties and adaptations, such as using communication strategies, may result in atypical utterances that are difficult for communication partners to understand. The coexistence of several communication problems compounds the difficulties faced in conversations and individuals with Parkinson’s disease are often dependent on cooperation with their communication partner to make themselves understood. PMID:28946714

Stratified source-sampling techniques for Monte Carlo eigenvalue analysis

International Nuclear Information System (INIS)

Mohamed, A.

1998-01-01

In 1995, at a conference on criticality safety, a special session was devoted to the Monte Carlo ''Eigenvalue of the World'' problem. Argonne presented a paper, at that session, in which the anomalies originally observed in that problem were reproduced in a much simplified model-problem configuration, and removed by a version of stratified source-sampling. In this paper, stratified source-sampling techniques are generalized and applied to three different Eigenvalue of the World configurations which take into account real-world statistical noise sources not included in the model problem, but which differ in the amount of neutronic coupling among the constituents of each configuration. It is concluded that, in Monte Carlo eigenvalue analysis of loosely-coupled arrays, the use of stratified source-sampling reduces the probability of encountering an anomalous result over that if conventional source-sampling methods are used. However, this gain in reliability is substantially less than that observed in the model-problem results

Inclusive Briefing and User Involvement

DEFF Research Database (Denmark)

Jensen, Per Anker

2011-01-01

Briefing is not just about specifying needs as requirements but also about evaluating how well design proposals fulfil needs and aspirations. Furthermore, briefing is not only about building design. Briefing starts at the preproject stage to create a basis for the project decision and can include...... by top management. The article describes the briefing processes and the methods for user involvement, identifies problem areas and points out possible improvements. The author was actively involved in the project as deputy project director, with responsibility for the briefing process, and is now...... includes a literature study on briefing and user involvement in building projects, and presents a case study of a major building project of a new headquarters and media centre for the Danish Broadcasting Corporation in Copenhagen. The building project was actively used as part of a corporate change process...

Generalized sampling in Julia

DEFF Research Database (Denmark)

Jacobsen, Christian Robert Dahl; Nielsen, Morten; Rasmussen, Morten Grud

2017-01-01

Generalized sampling is a numerically stable framework for obtaining reconstructions of signals in different bases and frames from their samples. For example, one can use wavelet bases for reconstruction given frequency measurements. In this paper, we will introduce a carefully documented toolbox...... for performing generalized sampling in Julia. Julia is a new language for technical computing with focus on performance, which is ideally suited to handle the large size problems often encountered in generalized sampling. The toolbox provides specialized solutions for the setup of Fourier bases and wavelets....... The performance of the toolbox is compared to existing implementations of generalized sampling in MATLAB....

Problem-solving in a Constructivist Environment

Directory of Open Access Journals (Sweden)

Lee Chien Sing

1999-01-01

Full Text Available The dynamic challenges of an increasingly borderless world buoyed by advances in telecommunications and information technology has resulted in educational reform and subsequently, a reconceptualisation of what constitutes a learner, learning and the influence of the learning environment on the process of learning. In keeping up with the changing trends and challenges of an increasingly networked, dynamic and challenging international community, means to provide an alternative environment that stimulates inquiry and equips learners with the skills needed to manage technological change and innovations must be considered. This paper discusses the importance of interaction, cognition and context, collaboration in a networked computer-mediated environment, the problem-solving approach as a catalyst in stimulating creative and critical thinking and in providing context for meaningful interaction and whether the interactive environment created through computer-mediated collaboration will motivate learners to be responsible for their own learning and be independent thinkers. The sample involved learners from three schools in three different countries. Findings conclude that a rich interactive environment must be personally relevant to the learner by simulating authentic problems without lowering the degree of cognitive complexity. Review in curriculum, assessment and teacher training around constructivist principles are also imperative as these interrelated factors form part of the learning process system.

The effects of using diagramming as a representational technique on high school students' achievement in solving math word problems

Science.gov (United States)

Banerjee, Banmali

Methods and procedures for successfully solving math word problems have been, and continue to be a mystery to many U.S. high school students. Previous studies suggest that the contextual and mathematical understanding of a word problem, along with the development of schemas and their related external representations, positively contribute to students' accomplishments when solving word problems. Some studies have examined the effects of diagramming on students' abilities to solve word problems that only involved basic arithmetic operations. Other studies have investigated how instructional models that used technology influenced students' problem solving achievements. Still other studies have used schema-based instruction involving students with learning disabilities. No study has evaluated regular high school students' achievements in solving standard math word problems using a diagramming technique without technological aid. This study evaluated students' achievement in solving math word problems using a diagramming technique. Using a quasi-experimental experimental pretest-posttest research design, quantitative data were collected from 172 grade 11 Hispanic English language learners (ELLS) and African American learners whose first language is English (EFLLs) in 18 classes at an inner city high school in Northern New Jersey. There were 88 control and 84 experimental students. The pretest and posttest of each participating student and samples of the experimental students' class assignments provided the qualitative data for the study. The data from this study exhibited that the diagramming method of solving math word problems significantly improved student achievement in the experimental group (pvocabulary and symbols used in word problems and that both ELLs and EFLLs improved their problem solving success through careful attention to the creation and labeling of diagrams to represent the mathematics involved in standard word problems. Although Learnertype (ELL, EFLL

Determination of optimal self-drive tourism route using the orienteering problem method

Science.gov (United States)

Hashim, Zakiah; Ismail, Wan Rosmanira; Ahmad, Norfaieqah

2013-04-01

This paper was conducted to determine the optimal travel routes for self-drive tourism based on the allocation of time and expense by maximizing the amount of attraction scores assigned to each city involved. Self-drive tourism represents a type of tourism where tourists hire or travel by their own vehicle. It only involves a tourist destination which can be linked with a network of roads. Normally, the traveling salesman problem (TSP) and multiple traveling salesman problems (MTSP) method were used in the minimization problem such as determination the shortest time or distance traveled. This paper involved an alternative approach for maximization method which is maximize the attraction scores and tested on tourism data for ten cities in Kedah. A set of priority scores are used to set the attraction score at each city. The classical approach of the orienteering problem was used to determine the optimal travel route. This approach is extended to the team orienteering problem and the two methods were compared. These two models have been solved by using LINGO12.0 software. The results indicate that the model involving the team orienteering problem provides a more appropriate solution compared to the orienteering problem model.

Independent random sampling methods

CERN Document Server

Martino, Luca; Míguez, Joaquín

2018-01-01

This book systematically addresses the design and analysis of efficient techniques for independent random sampling. Both general-purpose approaches, which can be used to generate samples from arbitrary probability distributions, and tailored techniques, designed to efficiently address common real-world practical problems, are introduced and discussed in detail. In turn, the monograph presents fundamental results and methodologies in the field, elaborating and developing them into the latest techniques. The theory and methods are illustrated with a varied collection of examples, which are discussed in detail in the text and supplemented with ready-to-run computer code. The main problem addressed in the book is how to generate independent random samples from an arbitrary probability distribution with the weakest possible constraints or assumptions in a form suitable for practical implementation. The authors review the fundamental results and methods in the field, address the latest methods, and emphasize the li...

SAMPLING IN EXTERNAL AUDIT - THE MONETARY UNIT SAMPLING METHOD

Directory of Open Access Journals (Sweden)

E. Dascalu

2016-12-01

Full Text Available This article approaches the general issue of diminishing the evidence investigation space in audit activities, by means of sampling techniques, given that in the instance of a significant data volume an exhaustive examination of the assessed popula¬tion is not possible and/or effective. The general perspective of the presentation involves dealing with sampling risk, in essence, the risk that a selected sample may not be representative for the overall population, in correlation with the audit risk model and with the component parts of this model (inherent risk, control risk and non detection risk and highlights the inter-conditionings between these two models.

Bedwetting and behavioural and/or emotional problems

NARCIS (Netherlands)

Hirasing, R.A.; Leerdam, F. van; Bolk-Bennink, L.B.; Bosch, J.D.

1997-01-01

Objective: To assess the link between enuresis nocturna and the severity of behavioural and/or emotional problems in Dutch children and the course of these problems. Setting: West-Mine Region in the Netherlands: Subjects and methods: Prospective cohort study involving 66 of the 80 bedwetting

The Relationship between Motor Skills, Perceived Social Support, and Internalizing Problems in a Community Adolescent Sample.

Science.gov (United States)

Mancini, Vincent O; Rigoli, Daniela; Heritage, Brody; Roberts, Lynne D; Piek, Jan P

2016-01-01

Poor motor skills are associated with a range of psychosocial consequences, including internalizing (anxious and depressive) symptoms. The Elaborated Environmental Stress Hypothesis provides a causal framework to explain this association. The framework posits that motor skills impact internalizing problems through an indirect effect via perceived social support. However, empirical evaluation is required. We examined whether motor skills had an indirect effect on anxious and depressive symptoms via perceived family support domains. This study used a community sample of 93 adolescents (12-16 years). Participants completed measures of motor skills, perceived social support across three dimensions (family, friend, and significant other), depressive symptoms, and anxious symptoms. Age, gender, verbal IQ, and ADHD symptoms were included as control variables. Regression analysis using PROCESS revealed that motor skills had an indirect effect on depressive symptoms via perceived family support, but not by perceived friend support or significant other support. The negative association between motor skills and anxious symptoms was not mediated by any perceived social support domain. Findings are consistent with previous literature indicating an association between motor skills and internalizing problems. However, we identified a different pattern of relationships across anxious and depressive symptoms. While anxiety and depressive symptoms were highly correlated, motor skills had an indirect effect on depressive symptoms via perceived family support only. Our findings highlight the importance of family support as a potential protective factor in the onset of depressive symptoms. This study provides partial support for the Elaborated Environmental Stress Hypothesis, however further research is required.

The Relationship between Motor Skills, Perceived Social Support, and Internalizing Problems in a Community Adolescent Sample

Directory of Open Access Journals (Sweden)

Vincent Oreste Mancini

2016-04-01

Full Text Available Objectives: Poor motor skills are associated with a range of psychosocial consequences, including internalizing (anxious and depressive symptoms. The Elaborated Environmental Stress Hypothesis provides a causal framework to explain this association. The framework posits that motor skills impact internalizing problems through an indirect effect via perceived social support. However, empirical evaluation is required. We examined whether motor skills has an indirect effect on anxious and depressive symptoms via perceived family support domains. Methods: This study used a community sample of 93 adolescents (12-16 years. Participants completed measures of motor skills, perceived social support across three dimensions (family, friend, and significant other, depressive symptoms, and anxious symptoms. Age, gender, verbal IQ, and ADHD symptoms were included as control variables.Results: Regression analysis using PROCESS revealed that motor skills had an indirect effect on depressive symptoms via perceived family support, but not by perceived friend support or significant other support. The negative association between motor skills and anxious symptoms was not mediated by any perceived social support domain. Conclusions: Findings are consistent with previous literature indicating an association between motor skills and internalizing problems. However, we identified a different pattern of relationships across anxious and depressive symptoms. While anxiety and depressive symptoms were highly correlated, motor skills had an indirect effect on depressive symptoms via perceived family support only. Our findings highlight the importance of family support as a potential protective factor in the onset of depressive symptoms. This study provides partial support for the Elaborated Environmental Stress Hypothesis, however further research is required.

A boundary-optimized rejection region test for the two-sample binomial problem.

Science.gov (United States)

Gabriel, Erin E; Nason, Martha; Fay, Michael P; Follmann, Dean A

2018-03-30

Testing the equality of 2 proportions for a control group versus a treatment group is a well-researched statistical problem. In some settings, there may be strong historical data that allow one to reliably expect that the control proportion is one, or nearly so. While one-sample tests or comparisons to historical controls could be used, neither can rigorously control the type I error rate in the event the true control rate changes. In this work, we propose an unconditional exact test that exploits the historical information while controlling the type I error rate. We sequentially construct a rejection region by first maximizing the rejection region in the space where all controls have an event, subject to the constraint that our type I error rate does not exceed α for any true event rate; then with any remaining α we maximize the additional rejection region in the space where one control avoids the event, and so on. When the true control event rate is one, our test is the most powerful nonrandomized test for all points in the alternative space. When the true control event rate is nearly one, we demonstrate that our test has equal or higher mean power, averaging over the alternative space, than a variety of well-known tests. For the comparison of 4 controls and 4 treated subjects, our proposed test has higher power than all comparator tests. We demonstrate the properties of our proposed test by simulation and use our method to design a malaria vaccine trial. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Problem of cadmium, arsenic and zinc determination in enviroment samples

International Nuclear Information System (INIS)

Malyugin, M.S.; Luzhnova, M.A.; Lontsikh, S.V.

1983-01-01

Using the emission spectroscopy technique new information has been obtained on cadmium-, arsenic and zinc content in some reference samples (RS) of rocks and soils not previously certified as to the content of the elements, as well as in nealy issued RS of soils. Metrologic estimation of the results obtained is carried out. A comparison with the atomic-absorption analysis data as well as with those of the neutron-activation-, colorimetric and other methods of the analysis permits to refer to the advantages of using the spectrographic determination technique based on fractionated evaporation, in case of determining cadmium and arsenic in rocks and soils. Consideration of the results of cadmium, arsenic and zinc spectrography contributed greatly to the certification of reference samples of soils

Perturbation analysis of linear control problems

International Nuclear Information System (INIS)

Petkov, Petko; Konstantinov, Mihail

2017-01-01

The paper presents a brief overview of the technique of splitting operators, proposed by the authors and intended for perturbation analysis of control problems involving unitary and orthogonal matrices. Combined with the technique of Lyapunov majorants and the implementation of the Banach and Schauder fixed point principles, it allows to obtain rigorous non-local perturbation bounds for a set of sensitivity analysis problems. Among them are the reduction of linear systems into orthogonal canonical forms, the feedback synthesis problem and pole assignment problem in particular, as well as other important problems in control theory and linear algebra. Key words: perturbation analysis, canonical forms, feedback synthesis

Chorionic villus sampling and amniocentesis.

Science.gov (United States)

Brambati, Bruno; Tului, Lucia

2005-04-01

The advantages and disadvantages of common invasive methods for prenatal diagnosis are presented in light of new investigations. Several aspects of first-trimester chorionic villus sampling and mid-trimester amniocentesis remain controversial, especially fetal loss rate, feto-maternal complications, and the extension of both sampling methods to less traditional gestational ages (early amniocentesis, late chorionic villus sampling), all of which complicate genetic counseling. A recent randomized trial involving early amniocentesis and late chorionic villus sampling has confirmed previous studies, leading to the unquestionable conclusion that transabdominal chorionic villus sampling is safer. The old dispute over whether limb reduction defects are caused by chorionic villus sampling gains new vigor, with a paper suggesting that this technique has distinctive teratogenic effects. The large experience involving maternal and fetal complications following mid-trimester amniocentesis allows a better estimate of risk for comparison with chorionic villus sampling. Transabdominal chorionic villus sampling, which appears to be the gold standard sampling method for genetic investigations between 10 and 15 completed weeks, permits rapid diagnosis in high-risk cases detected by first-trimester screening of aneuploidies. Sampling efficiency and karyotyping reliability are as high as in mid-trimester amniocentesis with fewer complications, provided the operator has the required training, skill and experience.

A technique for extracting blood samples from mice in fire toxicity tests

Science.gov (United States)

Bucci, T. J.; Hilado, C. J.; Lopez, M. T.

1976-01-01

The extraction of adequate blood samples from moribund and dead mice has been a problem because of the small quantity of blood in each animal and the short time available between the animals' death and coagulation of the blood. These difficulties are particularly critical in fire toxicity tests because removal of the test animals while observing proper safety precautions for personnel is time-consuming. Techniques for extracting blood samples from mice were evaluated, and a technique was developed to obtain up to 0.8 ml of blood from a single mouse after death. The technique involves rapid exposure and cutting of the posterior vena cava and accumulation of blood in the peritoneal space. Blood samples of 0.5 ml or more from individual mice have been consistently obtained as much as 16 minutes after apparent death. Results of carboxyhemoglobin analyses of blood appeared reproducible and consistent with carbon monoxide concentrations in the exposure chamber.

L∞ Variational Problems with Running Costs and Constraints

International Nuclear Information System (INIS)

Aronsson, G.; Barron, E. N.

2012-01-01

Various approaches are used to derive the Aronsson–Euler equations for L ∞ calculus of variations problems with constraints. The problems considered involve holonomic, nonholonomic, isoperimetric, and isosupremic constraints on the minimizer. In addition, we derive the Aronsson–Euler equation for the basic L ∞ problem with a running cost and then consider properties of an absolute minimizer. Many open problems are introduced for further study.

Wet gas sampling

Energy Technology Data Exchange (ETDEWEB)

Welker, T.F.

1997-07-01

The quality of gas has changed drastically in the past few years. Most gas is wet with hydrocarbons, water, and heavier contaminants that tend to condense if not handled properly. If a gas stream is contaminated with condensables, the sampling of that stream must be done in a manner that will ensure all of the components in the stream are introduced into the sample container as the composite. The sampling and handling of wet gas is extremely difficult under ideal conditions. There are no ideal conditions in the real world. The problems related to offshore operations and other wet gas systems, as well as the transportation of the sample, are additional problems that must be overcome if the analysis is to mean anything to the producer and gatherer. The sampling of wet gas systems is decidedly more difficult than sampling conventional dry gas systems. Wet gas systems were generally going to result in the measurement of one heating value at the inlet of the pipe and a drastic reduction in the heating value of the gas at the outlet end of the system. This is caused by the fallout or accumulation of the heavier products that, at the inlet, may be in the vapor state in the pipeline; hence, the high gravity and high BTU. But, in fact, because of pressure and temperature variances, these liquids condense and form a liquid that is actually running down the pipe as a stream or is accumulated in drips to be blown from the system. (author)

Scalable posterior approximations for large-scale Bayesian inverse problems via likelihood-informed parameter and state reduction

Science.gov (United States)

Cui, Tiangang; Marzouk, Youssef; Willcox, Karen

2016-06-01

Two major bottlenecks to the solution of large-scale Bayesian inverse problems are the scaling of posterior sampling algorithms to high-dimensional parameter spaces and the computational cost of forward model evaluations. Yet incomplete or noisy data, the state variation and parameter dependence of the forward model, and correlations in the prior collectively provide useful structure that can be exploited for dimension reduction in this setting-both in the parameter space of the inverse problem and in the state space of the forward model. To this end, we show how to jointly construct low-dimensional subspaces of the parameter space and the state space in order to accelerate the Bayesian solution of the inverse problem. As a byproduct of state dimension reduction, we also show how to identify low-dimensional subspaces of the data in problems with high-dimensional observations. These subspaces enable approximation of the posterior as a product of two factors: (i) a projection of the posterior onto a low-dimensional parameter subspace, wherein the original likelihood is replaced by an approximation involving a reduced model; and (ii) the marginal prior distribution on the high-dimensional complement of the parameter subspace. We present and compare several strategies for constructing these subspaces using only a limited number of forward and adjoint model simulations. The resulting posterior approximations can rapidly be characterized using standard sampling techniques, e.g., Markov chain Monte Carlo. Two numerical examples demonstrate the accuracy and efficiency of our approach: inversion of an integral equation in atmospheric remote sensing, where the data dimension is very high; and the inference of a heterogeneous transmissivity field in a groundwater system, which involves a partial differential equation forward model with high dimensional state and parameters.

Strategies for achieving high sequencing accuracy for low diversity samples and avoiding sample bleeding using illumina platform.

Science.gov (United States)

Mitra, Abhishek; Skrzypczak, Magdalena; Ginalski, Krzysztof; Rowicka, Maga

2015-01-01

Sequencing microRNA, reduced representation sequencing, Hi-C technology and any method requiring the use of in-house barcodes result in sequencing libraries with low initial sequence diversity. Sequencing such data on the Illumina platform typically produces low quality data due to the limitations of the Illumina cluster calling algorithm. Moreover, even in the case of diverse samples, these limitations are causing substantial inaccuracies in multiplexed sample assignment (sample bleeding). Such inaccuracies are unacceptable in clinical applications, and in some other fields (e.g. detection of rare variants). Here, we discuss how both problems with quality of low-diversity samples and sample bleeding are caused by incorrect detection of clusters on the flowcell during initial sequencing cycles. We propose simple software modifications (Long Template Protocol) that overcome this problem. We present experimental results showing that our Long Template Protocol remarkably increases data quality for low diversity samples, as compared with the standard analysis protocol; it also substantially reduces sample bleeding for all samples. For comprehensiveness, we also discuss and compare experimental results from alternative approaches to sequencing low diversity samples. First, we discuss how the low diversity problem, if caused by barcodes, can be avoided altogether at the barcode design stage. Second and third, we present modified guidelines, which are more stringent than the manufacturer's, for mixing low diversity samples with diverse samples and lowering cluster density, which in our experience consistently produces high quality data from low diversity samples. Fourth and fifth, we present rescue strategies that can be applied when sequencing results in low quality data and when there is no more biological material available. In such cases, we propose that the flowcell be re-hybridized and sequenced again using our Long Template Protocol. Alternatively, we discuss how

Strategies for achieving high sequencing accuracy for low diversity samples and avoiding sample bleeding using illumina platform.

Directory of Open Access Journals (Sweden)

Abhishek Mitra

Full Text Available Sequencing microRNA, reduced representation sequencing, Hi-C technology and any method requiring the use of in-house barcodes result in sequencing libraries with low initial sequence diversity. Sequencing such data on the Illumina platform typically produces low quality data due to the limitations of the Illumina cluster calling algorithm. Moreover, even in the case of diverse samples, these limitations are causing substantial inaccuracies in multiplexed sample assignment (sample bleeding. Such inaccuracies are unacceptable in clinical applications, and in some other fields (e.g. detection of rare variants. Here, we discuss how both problems with quality of low-diversity samples and sample bleeding are caused by incorrect detection of clusters on the flowcell during initial sequencing cycles. We propose simple software modifications (Long Template Protocol that overcome this problem. We present experimental results showing that our Long Template Protocol remarkably increases data quality for low diversity samples, as compared with the standard analysis protocol; it also substantially reduces sample bleeding for all samples. For comprehensiveness, we also discuss and compare experimental results from alternative approaches to sequencing low diversity samples. First, we discuss how the low diversity problem, if caused by barcodes, can be avoided altogether at the barcode design stage. Second and third, we present modified guidelines, which are more stringent than the manufacturer's, for mixing low diversity samples with diverse samples and lowering cluster density, which in our experience consistently produces high quality data from low diversity samples. Fourth and fifth, we present rescue strategies that can be applied when sequencing results in low quality data and when there is no more biological material available. In such cases, we propose that the flowcell be re-hybridized and sequenced again using our Long Template Protocol. Alternatively

A suite of benchmark and challenge problems for enhanced geothermal systems

Energy Technology Data Exchange (ETDEWEB)

White, Mark; Fu, Pengcheng; McClure, Mark; Danko, George; Elsworth, Derek; Sonnenthal, Eric; Kelkar, Sharad; Podgorney, Robert

2017-11-06

A diverse suite of numerical simulators is currently being applied to predict or understand the performance of enhanced geothermal systems (EGS). To build confidence and identify critical development needs for these analytical tools, the United States Department of Energy, Geothermal Technologies Office sponsored a Code Comparison Study (GTO-CCS), with participants from universities, industry, and national laboratories. A principal objective for the study was to create a community forum for improvement and verification of numerical simulators for EGS modeling. Teams participating in the study were those representing U.S. national laboratories, universities, and industries, and each team brought unique numerical simulation capabilities to bear on the problems. Two classes of problems were developed during the study, benchmark problems and challenge problems. The benchmark problems were structured to test the ability of the collection of numerical simulators to solve various combinations of coupled thermal, hydrologic, geomechanical, and geochemical processes. This class of problems was strictly defined in terms of properties, driving forces, initial conditions, and boundary conditions. The challenge problems were based on the enhanced geothermal systems research conducted at Fenton Hill, near Los Alamos, New Mexico, between 1974 and 1995. The problems involved two phases of research, stimulation, development, and circulation in two separate reservoirs. The challenge problems had specific questions to be answered via numerical simulation in three topical areas: 1) reservoir creation/stimulation, 2) reactive and passive transport, and 3) thermal recovery. Whereas the benchmark class of problems were designed to test capabilities for modeling coupled processes under strictly specified conditions, the stated objective for the challenge class of problems was to demonstrate what new understanding of the Fenton Hill experiments could be realized via the application of

Multiscale sampling model for motion integration.

Science.gov (United States)

Sherbakov, Lena; Yazdanbakhsh, Arash

2013-09-30

Biologically plausible strategies for visual scene integration across spatial and temporal domains continues to be a challenging topic. The fundamental question we address is whether classical problems in motion integration, such as the aperture problem, can be solved in a model that samples the visual scene at multiple spatial and temporal scales in parallel. We hypothesize that fast interareal connections that allow feedback of information between cortical layers are the key processes that disambiguate motion direction. We developed a neural model showing how the aperture problem can be solved using different spatial sampling scales between LGN, V1 layer 4, V1 layer 6, and area MT. Our results suggest that multiscale sampling, rather than feedback explicitly, is the key process that gives rise to end-stopped cells in V1 and enables area MT to solve the aperture problem without the need for calculating intersecting constraints or crafting intricate patterns of spatiotemporal receptive fields. Furthermore, the model explains why end-stopped cells no longer emerge in the absence of V1 layer 6 activity (Bolz & Gilbert, 1986), why V1 layer 4 cells are significantly more end-stopped than V1 layer 6 cells (Pack, Livingstone, Duffy, & Born, 2003), and how it is possible to have a solution to the aperture problem in area MT with no solution in V1 in the presence of driving feedback. In summary, while much research in the field focuses on how a laminar architecture can give rise to complicated spatiotemporal receptive fields to solve problems in the motion domain, we show that one can reframe motion integration as an emergent property of multiscale sampling achieved concurrently within lamina and across multiple visual areas.

A New On-the-Fly Sampling Method for Incoherent Inelastic Thermal Neutron Scattering Data in MCNP6

Energy Technology Data Exchange (ETDEWEB)

Pavlou, Andrew Theodore [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Forrest B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ji, Wei [Rensselaer Polytechnic Inst., Troy, NY (United States)

2014-09-02

At thermal energies, the scattering of neutrons in a system is complicated by the comparable velocities of the neutron and target, resulting in competing upscattering and downscattering events. The neutron wavelength is also similar in size to the target's interatomic spacing making the scattering process a quantum mechanical problem. Because of the complicated nature of scattering at low energies, the thermal data files in ACE format used in continuous-energy Monte Carlo codes are quite large { on the order of megabytes for a single temperature and material. In this paper, a new storage and sampling method is introduced that is orders of magnitude less in size and is used to sample scattering parameters at any temperature on-the-fly. In addition to the reduction in storage, the need to pre-generate thermal scattering data tables at fine temperatures has been eliminated. This is advantageous for multiphysics simulations which may involve temperatures not known in advance. A new module was written for MCNP6 that bypasses the current S(α,β) table lookup in favor of the new format. The new on-the-fly sampling method was tested for graphite for two benchmark problems at ten temperatures: 1) an eigenvalue test with a fuel compact of uranium oxycarbide fuel homogenized into a graphite matrix, 2) a surface current test with a \\broomstick" problem with a monoenergetic point source. The largest eigenvalue difference was 152pcm for T= 1200K. For the temperatures and incident energies chosen for the broomstick problem, the secondary neutron spectrum showed good agreement with the traditional S(α,β) sampling method. These preliminary results show that sampling thermal scattering data on-the-fly is a viable option to eliminate both the storage burden of keeping thermal data at discrete temperatures and the need to know temperatures before simulation runtime.

A Problem-Solving Model for Literacy Coaching Practice

Science.gov (United States)

Toll, Cathy A.

2017-01-01

Literacy coaches are more effective when they have a clear plan for their collaborations with teachers. This article provides details of such a plan, which involves identifying a problem, understanding the problem, deciding what to do differently, and trying something different. For each phase of the problem-solving model, there are key tasks for…

Enhancing sampling design in mist-net bat surveys by accounting for sample size optimization

OpenAIRE

Trevelin, Leonardo Carreira; Novaes, Roberto Leonan Morim; Colas-Rosas, Paul François; Benathar, Thayse Cristhina Melo; Peres, Carlos A.

2017-01-01

The advantages of mist-netting, the main technique used in Neotropical bat community studies to date, include logistical implementation, standardization and sampling representativeness. Nonetheless, study designs still have to deal with issues of detectability related to how different species behave and use the environment. Yet there is considerable sampling heterogeneity across available studies in the literature. Here, we approach the problem of sample size optimization. We evaluated the co...

Behaviour problems in children with dyslexia.

Science.gov (United States)

Heiervang, E; Stevenson, J; Lund, A; Hugdahl, K

2001-01-01

The association between behaviour problems and dyslexia was assessed in a population sample of 10- to 12-year-old children. Twenty-five dyslexic children and a matched control group were recruited through a screening in primary schools in the city of Bergen, Norway. For the assessment of behaviour problems the Child Behavior Checklist (CBCL), Teacher Self Report (TRF), and Youth Self Report (YSR) were filled out by parents, teachers, and children, respectively. Information on health and developmental factors were obtained from parents on a separate questionnaire designed for the study. The dyslexic group had significantly more behaviour problems than the control group according to both the CBCL and the TRF. On the YSR there was no significant difference between the groups. Dyslexic children had higher CBCL and TRF scores on the Total Behaviour Problem scale, the Internalizing and Externalizing subdomains, and the Attention problem subscale. The groups differed in social background, prenatal risk factors, birth weight, preschool language problems, and IQ, but these variables showed no relationship to the level of behaviour problems in the present sample. We conclude that pre-adolescent dyslexic children show a wide range of behaviour problems that cannot be attributed to social or developmental background variables.

Monte Carlo source convergence and the Whitesides problem

International Nuclear Information System (INIS)

Blomquist, R. N.

2000-01-01

The issue of fission source convergence in Monte Carlo eigenvalue calculations is of interest because of the potential consequences of erroneous criticality safety calculations. In this work, the authors compare two different techniques to improve the source convergence behavior of standard Monte Carlo calculations applied to challenging source convergence problems. The first method, super-history powering, attempts to avoid discarding important fission sites between generations by delaying stochastic sampling of the fission site bank until after several generations of multiplication. The second method, stratified sampling of the fission site bank, explicitly keeps the important sites even if conventional sampling would have eliminated them. The test problems are variants of Whitesides' Criticality of the World problem in which the fission site phase space was intentionally undersampled in order to induce marginally intolerable variability in local fission site populations. Three variants of the problem were studied, each with a different degree of coupling between fissionable pieces. Both the superhistory powering method and the stratified sampling method were shown to improve convergence behavior, although stratified sampling is more robust for the extreme case of no coupling. Neither algorithm completely eliminates the loss of the most important fissionable piece, and if coupling is absent, the lost piece cannot be recovered unless its sites from earlier generations have been retained. Finally, criteria for measuring source convergence reliability are proposed and applied to the test problems

Examining Understandings of Parent Involvement in Early Childhood Programs

Science.gov (United States)

Hilado, Aimee V.; Kallemeyn, Leanne; Phillips, Lauren

2013-01-01

The importance of parent involvement in children's development and learning is increasingly recognized in the research literature and in federal and state policies; however, no unified definition of parent involvement exists. This study examined different understandings and definitions of parent involvement in a sample of administrators of…

Fixed Point Approach to Bagley Torvik Problem

Directory of Open Access Journals (Sweden)

Lale CONA

2017-10-01

Full Text Available In the present paper, a sufficient condition for existence and uniqueness of Bagley Torvik problem is obtained. The theorem on existence and uniqueness is established. This approach permits us to use fixed point iteration method to solve problem for differential equation involving derivatives of nonlinear order.

Activities: Activities to Introduce Maxima-Minima Problems.

Science.gov (United States)

Pleacher, David

1991-01-01

Presented are student activities that involve two standard problems from geometry and calculus--the volume of a box and the bank shot on a pool table. Problem solving is emphasized as a method of inquiry and application with descriptions of the results using graphical, numerical, and physical models. (JJK)

Approaching messy problems: strategies for environmental analysis

Science.gov (United States)

L. M. Reid; R. R. Ziemer; T. E. Lisle

1996-01-01

Environmental problems are never neatly defined. Instead, each is a tangle of interacting processes whose manifestation and interpretation are warped by the vagaries of time, weather, expectation, and economics. Each problem involves livelihoods, values, and numerous specialized disciplines. Nevertheless, federal agencies in the Pacific Northwest have been given the...

Two heads are better than one: the association between condom decision-making and condom use errors and problems.

Science.gov (United States)

Crosby, R; Milhausen, R; Sanders, S A; Graham, C A; Yarber, W L

2008-06-01

This exploratory study compared the frequency of condom use errors and problems between men reporting that condom use for penile-vaginal sex was a mutual decision compared with men making the decision unilaterally. Nearly 2000 people completed a web-based questionnaire. A sub-sample of 660 men reporting that they last used a condom for penile-vaginal sex (within the past three months) was analysed. Nine condom use errors/problems were assessed. Multivariate analyses controlled for men's age, marital status, and level of experience using condoms. Men's unilateral decision-making was associated with increased odds of removing condoms before sex ended (adjusted odds ratio (AOR) 2.51, p = 0.002), breakage (AOR 3.90, p = 0.037), and slippage during withdrawal (AOR 2.04, p = 0.019). Men's self-reported level of experience using condoms was significantly associated with seven out of nine errors/problems, with those indicating less experience consistently reporting more errors/problems. Findings suggest that female involvement in the decision to use condoms for penile-vaginal sex may be partly protective against some condom errors/problems. Men's self-reported level of experience using condoms may be a useful indicator of the need for education designed to promote the correct use of condoms. Education programmes may benefit men by urging them to involve their female partner in condom use decisions.

Constructivist, Problem-Based Learning Does Work: A Meta-Analysis of Curricular Comparisons Involving a Single Medical School

Science.gov (United States)

Schmidt, Henk G.; van der Molen, Henk T.; te Winkel, Wilco W. R.; Wijnen, Wynand H. F. W.

2009-01-01

Effects of problem-based learning as reported in curricular comparison studies have been shown to be inconsistent over different medical schools. Therefore, we decided to summarize effects of a single well-established problem-based curriculum rather than to add up sometimes-conflicting findings from different problem-based curricula. Effect sizes…

The youth of Russia and Serbia: Social trust and key generational problems

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U V Šuvaković

2016-12-01

Full Text Available The Sociological Laboratory of the Peoples’ Friendship University of Russia has conducted a number of comparative studies using the method of mass surveys on the representative samples of student youth in different countries and different regions within them. The results of these surveys were presented in the articles in both Russian and foreign scientific journals, and we hope to establish a kind of tradition to publish two types of articles based on the comparative research data: in 2015 we focused mainly on methodological and technical issues to identify key problems of the comparative analysis in cross-cultural studies that become evident only if you conduct an empirical research yourself - from the first step of setting the problem and approving it by all the sides involved to the last step of interpreting and comparing the data obtained. From 2016 to the end of the Russian Foundation for Humanities’ support in 2017 we will focus on the results of our comparative studies together with our colleagues that participate in the project and conduct surveys on the student samples in their countries using the same questionnaire (with the inevitable and predictable changes as we do. The authors present only a small part of the empirical data revealing the perception of the Serbian and Russian student youth of their own situation through the identification of the key problems of the younger generations and the trust to the basic social institutions. This is a deliberate decision of the authors - to leave other topics (and corresponding questions out in order to address them more thoroughly later in the further analysis and publications. The article considers the results of the empirical studies conducted on the representative samples of students of two Serbian universities - University of Belgrade and University of Pristina with the head-office in Kosovska Mitrovica, and on the representative sample of Moscow students (a part of the sample was

Assessment of computer-related health problems among post-graduate nursing students.

Science.gov (United States)

Khan, Shaheen Akhtar; Sharma, Veena

2013-01-01

The study was conducted to assess computer-related health problems among post-graduate nursing students and to develop a Self Instructional Module for prevention of computer-related health problems in a selected university situated in Delhi. A descriptive survey with co-relational design was adopted. A total of 97 samples were selected from different faculties of Jamia Hamdard by multi stage sampling with systematic random sampling technique. Among post-graduate students, majority of sample subjects had average compliance with computer-related ergonomics principles. As regards computer related health problems, majority of post graduate students had moderate computer-related health problems, Self Instructional Module developed for prevention of computer-related health problems was found to be acceptable by the post-graduate students.

Abstract Cauchy problems three approaches

CERN Document Server

Melnikova, Irina V

2001-01-01

Although the theory of well-posed Cauchy problems is reasonably understood, ill-posed problems-involved in a numerous mathematical models in physics, engineering, and finance- can be approached in a variety of ways. Historically, there have been three major strategies for dealing with such problems: semigroup, abstract distribution, and regularization methods. Semigroup and distribution methods restore well-posedness, in a modern weak sense. Regularization methods provide approximate solutions to ill-posed problems. Although these approaches were extensively developed over the last decades by many researchers, nowhere could one find a comprehensive treatment of all three approaches.Abstract Cauchy Problems: Three Approaches provides an innovative, self-contained account of these methods and, furthermore, demonstrates and studies some of the profound connections between them. The authors discuss the application of different methods not only to the Cauchy problem that is not well-posed in the classical sense, b...

Particle Swarm Optimization and Uncertainty Assessment in Inverse Problems

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José L. G. Pallero

2018-01-01

Full Text Available Most inverse problems in the industry (and particularly in geophysical exploration are highly underdetermined because the number of model parameters too high to achieve accurate data predictions and because the sampling of the data space is scarce and incomplete; it is always affected by different kinds of noise. Additionally, the physics of the forward problem is a simplification of the reality. All these facts result in that the inverse problem solution is not unique; that is, there are different inverse solutions (called equivalent, compatible with the prior information that fits the observed data within similar error bounds. In the case of nonlinear inverse problems, these equivalent models are located in disconnected flat curvilinear valleys of the cost-function topography. The uncertainty analysis consists of obtaining a representation of this complex topography via different sampling methodologies. In this paper, we focus on the use of a particle swarm optimization (PSO algorithm to sample the region of equivalence in nonlinear inverse problems. Although this methodology has a general purpose, we show its application for the uncertainty assessment of the solution of a geophysical problem concerning gravity inversion in sedimentary basins, showing that it is possible to efficiently perform this task in a sampling-while-optimizing mode. Particularly, we explain how to use and analyze the geophysical models sampled by exploratory PSO family members to infer different descriptors of nonlinear uncertainty.

Toxicological Analysis of Some Drugs of Abuse in Biological Samples

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Anne Marie Ciobanu

2015-10-01

Full Text Available Consumption of drugs of abuse is a scourge of modern world. Abuse, drug addiction and their consequences are one of the major current problems of European society because of the significant repercussions in individual, family, social and economic level. In this context, toxicological analysis of the drugs of abuse in biological samples is a useful tool for: diagnosis of drug addiction, checking an auto-response, mandatory screening in some treatment programs, identification of a substance in the case of an overdose, determining compliance of the treatment. The present paper aims to address the needs of healthcare professionals involved in drugs addiction treatment through systematic presentation of information regarding their toxicological analysis. Basically, it is a tool that help you to select the suitable biological sample and the right collecting time, as well as the proper analysis technique, depending on the purpose of analysis, pharmacokinetic characteristics of the drugs of abuse, available equipment and staff expertise.

Problems with sampling desert tortoises: A simulation analysis based on field data

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Freilich, J.E.; Camp, R.J.; Duda, J.J.; Karl, A.E.

2005-01-01

The desert tortoise (Gopherus agassizii) was listed as a U.S. threatened species in 1990 based largely on population declines inferred from mark-recapture surveys of 2.59-km2 (1-mi2) plots. Since then, several census methods have been proposed and tested, but all methods still pose logistical or statistical difficulties. We conducted computer simulations using actual tortoise location data from 2 1-mi2 plot surveys in southern California, USA, to identify strengths and weaknesses of current sampling strategies. We considered tortoise population estimates based on these plots as "truth" and then tested various sampling methods based on sampling smaller plots or transect lines passing through the mile squares. Data were analyzed using Schnabel's mark-recapture estimate and program CAPTURE. Experimental subsampling with replacement of the 1-mi2 data using 1-km2 and 0.25-km2 plot boundaries produced data sets of smaller plot sizes, which we compared to estimates from the 1-mi 2 plots. We also tested distance sampling by saturating a 1-mi 2 site with computer simulated transect lines, once again evaluating bias in density estimates. Subsampling estimates from 1-km2 plots did not differ significantly from the estimates derived at 1-mi2. The 0.25-km2 subsamples significantly overestimated population sizes, chiefly because too few recaptures were made. Distance sampling simulations were biased 80% of the time and had high coefficient of variation to density ratios. Furthermore, a prospective power analysis suggested limited ability to detect population declines as high as 50%. We concluded that poor performance and bias of both sampling procedures was driven by insufficient sample size, suggesting that all efforts must be directed to increasing numbers found in order to produce reliable results. Our results suggest that present methods may not be capable of accurately estimating desert tortoise populations.

Bayesian Simultaneous Estimation for Means in k Sample Problems

OpenAIRE

Imai, Ryo; Kubokawa, Tatsuya; Ghosh, Malay

2017-01-01

This paper is concerned with the simultaneous estimation of k population means when one suspects that the k means are nearly equal. As an alternative to the preliminary test estimator based on the test statistics for testing hypothesis of equal means, we derive Bayesian and minimax estimators which shrink individual sample means toward a pooled mean estimator given under the hypothesis. Interestingly, it is shown that both the preliminary test estimator and the Bayesian minimax shrinkage esti...

"What constitutes a 'problem'?" Producing 'alcohol problems' through online counselling encounters.

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Savic, Michael; Ferguson, Nyssa; Manning, Victoria; Bathish, Ramez; Lubman, Dan I

2017-08-01

Typically, health policy, practice and research views alcohol and other drug (AOD) 'problems' as objective things waiting to be detected, diagnosed and treated. However, this approach to policy development and treatment downplays the role of clinical practices, tools, discourses, and systems in shaping how AOD use is constituted as a 'problem'. For instance, people might present to AOD treatment with multiple psycho-social concerns, but usually only a singular AOD-associated 'problem' is considered serviceable. As the assumed nature of 'the serviceable problem' influences what treatment responses people receive, and how they may come to be enacted as 'addicted' or 'normal' subjects, it is important to subject clinical practices of problem formulation to critical analysis. Given that the reach of AOD treatment has expanded via the online medium, in this article we examine how 'problems' are produced in online alcohol counselling encounters involving people aged 55 and over. Drawing on poststructural approaches to problematisation, we not only trace how and what 'problems' are produced, but also what effects these give rise to. We discuss three approaches to problem formulation: (1) Addiction discourses at work; (2) Moving between concerns and alcohol 'problems'; (3) Making 'problems' complex and multiple. On the basis of this analysis, we argue that online AOD counselling does not just respond to pre-existing 'AOD problems'. Rather, through the social and clinical practices of formulation at work in clinical encounters, online counselling also produces them. Thus, given a different set of circumstances, practices and relations, 'problems' might be defined or emerge differently-perhaps not as 'problems' at all or perhaps as different kinds of concerns. We conclude by highlighting the need for a critical reflexivity in AOD treatment and policy in order to open up possibilities for different ways of engaging with, and responding to, people's needs in their complexity

Errors of Students Learning With React Strategy in Solving the Problems of Mathematical Representation Ability

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Delsika Pramata Sari

2017-06-01

Full Text Available The purpose of this study was to investigate the errors experienced by students learning with REACT strategy and traditional learning in solving problems of mathematical representation ability. This study used quasi experimental pattern with static-group comparison design. The subjects of this study were 47 eighth grade students of junior high school in Bandung consisting of two samples. The instrument used was a test to measure students' mathematical representation ability. The reliability coefficient about the mathematical representation ability was 0.56. The most prominent errors of mathematical representation ability of students learning with REACT strategy and traditional learning, was on indicator that solving problem involving arithmetic symbols (symbolic representation. In addition, errors were also experienced by many students with traditional learning on the indicator of making the image of a real world situation to clarify the problem and facilitate its completion (visual representation.

Lot quality assurance sampling for screening communities hyperendemic for Schistosoma mansoni.

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Rabarijaona, L P; Boisier, P; Ravaoalimalala, V E; Jeanne, I; Roux, J F; Jutand, M A; Salamon, R

2003-04-01

Lot quality assurance sampling (LQAS) was evaluated for rapid low cost identification of communities where Schistosoma mansoni infection was hyperendemic in southern Madagascar. In the study area, S. mansoni infection shows very focused and heterogeneous distribution requiring multifariousness of local surveys. One sampling plan was tested in the field with schoolchildren and several others were simulated in the laboratory. Randomization and stool specimen collection were performed by voluntary teachers under direct supervision of the study staff and no significant problem occurred. As expected from Receiver Operating Characteristic (ROC) curves, all sampling plans allowed correct identification of hyperendemic communities and of most of the hypoendemic ones. Frequent misclassifications occurred for communities with intermediate prevalence and the cheapest plans had very low specificity. The study confirmed that LQAS would be a valuable tool for large scale screening in a country with scarce financial and staff resources. Involving teachers, appeared to be quite feasible and should not lower the reliability of surveys. We recommend that the national schistosomiasis control programme systematically uses LQAS for identification of communities, provided that sample sizes are adapted to the specific epidemiological patterns of S. mansoni infection in the main regions.

Optimal resampling for the noisy OneMax problem

OpenAIRE

Liu, Jialin; Fairbank, Michael; Pérez-Liébana, Diego; Lucas, Simon M.

2016-01-01

The OneMax problem is a standard benchmark optimisation problem for a binary search space. Recent work on applying a Bandit-Based Random Mutation Hill-Climbing algorithm to the noisy OneMax Problem showed that it is important to choose a good value for the resampling number to make a careful trade off between taking more samples in order to reduce noise, and taking fewer samples to reduce the total computational cost. This paper extends that observation, by deriving an analytical expression f...

Evaluation of energy deposition by 153Sm in small samples

International Nuclear Information System (INIS)

Cury, M.I.C.; Siqueira, P.T.D.; Yoriyaz, H.; Coelho, P.R.P.; Da Silva, M.A.; Okazaki, K.

2002-01-01

Aim: This work presents evaluations of the absorbed dose by 'in vitro' blood cultures when mixed with 153 Sm solutions of different concentrations. Although 153 Sm is used as radiopharmaceutical mainly due to its beta emission, which is short-range radiation, it also emits gamma radiation which has a longer-range penetration. Therefore it turns to be a difficult task to determine the absorbed dose by small samples where the infinite approximation is no longer valid. Materials and Methods: MCNP-4C (Monte Carlo N - Particle transport code) has been used to perform the evaluations. It is not a deterministic code that calculates the value of a specific quantity solving the physical equations involved in the problem, but a virtual experiment where the events related to the problems are simulated and the concerned quantities are tallied. MCNP also stands out by its possibilities to specify geometrically any problem. However, these features, among others, turns MCNP in a time consuming code. The simulated problem consists of a cylindrical plastic tube with 1.5 cm internal diameter and 0.1cm thickness. It also has 2.0 cm height conic bottom end, so that the represented sample has 4.0 ml ( consisted by 1 ml of blood and 3 ml culture medium). To evaluate the energy deposition in the blood culture in each 153 Sm decay, the problem has been divided in 3 steps to account to the β- emissions (which has a continuum spectrum), gammas and conversion and Auger electrons emissions. Afterwards each emission contribution was weighted and summed to present the final value. Besides this radiation 'fragmentation', simulations were performed for many different amounts of 153 Sm solution added to the sample. These amounts cover a range from 1μl to 0.5 ml. Results: The average energy per disintegration of 153 Sm is 331 keV [1]. Gammas account for 63 keV and β-, conversion and Auger electrons account for 268 keV. The simulations performed showed an average energy deposition of 260 ke

Problems of Dirty Hands as a Species of Moral Conflicts

OpenAIRE

Kramer, Matthew Henry

2018-01-01

Every problem of dirty hands is a moral conflict, but not every moral conflict is a problem of dirty hands. Every problem of dirty hands involves the prospect of evil conduct–conduct which will be evil if undertaken at all or which would be evil if undertaken in the absence of a searing moral dilemma–whereas not every moral conflict involves the prospect of evil conduct. To support and clarify the claims in the preceding two sentences, this paper will need to elucidate the nature of moral con...

A frictional contact problem with wear involving elastic-viscoplastic materials with damage and thermal effects

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Abdelmoumene Djabi

2015-05-01

Full Text Available We consider a mathematical problem for quasistatic contact between a thermo-elastic-viscoplastic body with damage and an obstacle. The contact is frictional and bilateral with a moving rigid foundation which results in the wear of the contacting surface. We employ the thermo-elasticviscoplastic with damage constitutive law for the material. The damage of the material caused by elastic deformations. The evolution of the damage is described by an inclusion of parabolic type. The problem is formulated as a coupled system of an elliptic variational inequality for the displacement, a parabolic variational inequality for the damage and the heat equation for the temperature. We establish a variational formulation for the model and we prove the existence of a unique weak solution to the problem. The proof is based on a classical existence and uniqueness result on parabolic inequalities, differential equations and fixed point arguments.

Relapsing polychondritis and airway involvement.

Science.gov (United States)

Ernst, Armin; Rafeq, Samaan; Boiselle, Phillip; Sung, Arthur; Reddy, Chakravarthy; Michaud, Gaetane; Majid, Adnan; Herth, Felix J F; Trentham, David

2009-04-01

To assess the prevalence and characteristics of airway involvement in relapsing polychondritis (RP). Retrospective chart review and data analysis of RP patients seen in the Rheumatology Clinic and the Complex Airway Center at Beth Israel Deaconess Medical Center from January 2004 through February 2008. RP was diagnosed in 145 patients. Thirty-one patients had airway involvement, a prevalence of 21%. Twenty-two patients were women (70%), and they were between 11 and 61 years of age (median age, 42 years) at the time of first symptoms. Airway symptoms were the first manifestation of disease in 17 patients (54%). Dyspnea was the most common symptom in 20 patients (64%), followed by cough, stridor, and hoarseness. Airway problems included the following: subglottic stenosis (n = 8; 26%); focal and diffuse malacia (n = 15; 48%); and focal stenosis in different areas of the bronchial tree in the rest of the patients. Twelve patients (40%) required and underwent intervention including balloon dilatation, stent placement, tracheotomy, or a combination of the above with good success. The majority of patients experienced improvement in airway symptoms after intervention. One patient died during the follow-up period from the progression of airway disease. The rest of the patients continue to undergo periodic evaluation and intervention. In this largest cohort described in the English language literature, we found symptomatic airway involvement in RP to be common and at times severe. The nature of airway problems is diverse, with tracheomalacia being the most common. Airway intervention is frequently required and in experienced hands results in symptom improvement.

Java problem-based learning

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Goran P, Šimić

2012-01-01

Full Text Available The paper describes the self-directed problem-based learning system (PBL named Java PBL. The expert module is the kernel of Java PBL. It involves a specific domain model, a problem generator and a solution generator. The overall system architecture is represented in the paper. Java PBL can act as the stand-alone system, but it is also designed to provide support to learning management systems (LMSs. This is provided by a modular design of the system. An LMS can offer the declarative knowledge only. Java PBL offers the procedural knowledge and the progress of the learner programming skills. The free navigation, unlimited numbers of problems and recommendations represent the main pedagogical strategies and tactics implemented into the system.