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Sample records for variables path analysis

  1. Variability, correlation and path coefficient analysis of seedling traits ...

    African Journals Online (AJOL)

    Indirect selection is a useful means for improving yield in cotton crop. The objective of the present study was to determine the genetic variability, broad sense heritability, genetic advance and correlation among the six seedling traits and their direct and indirect effects on cotton yield by using path coefficient analysis.

  2. PATH ANALYSIS WITH LOGISTIC REGRESSION MODELS : EFFECT ANALYSIS OF FULLY RECURSIVE CAUSAL SYSTEMS OF CATEGORICAL VARIABLES

    OpenAIRE

    Nobuoki, Eshima; Minoru, Tabata; Geng, Zhi; Department of Medical Information Analysis, Faculty of Medicine, Oita Medical University; Department of Applied Mathematics, Faculty of Engineering, Kobe University; Department of Probability and Statistics, Peking University

    2001-01-01

    This paper discusses path analysis of categorical variables with logistic regression models. The total, direct and indirect effects in fully recursive causal systems are considered by using model parameters. These effects can be explained in terms of log odds ratios, uncertainty differences, and an inner product of explanatory variables and a response variable. A study on food choice of alligators as a numerical exampleis reanalysed to illustrate the present approach.

  3. Variability, heritability, character association, path analysis and morphological diversity in snake gourd

    Directory of Open Access Journals (Sweden)

    A.S.M. Mahbubur Rahman Khan

    2016-11-01

    Full Text Available Genetic variability, heritability and path coefficient analysis were studied in 21 genotypes of snake gourd. The phenotypic coefficient of variations was found slightly higher than the genotypic coefficient of variations for all characters studied, indicating that the apparent variation is not only genetic but also influenced by the growing environment in the expression of the traits. The genotypic coefficient of variation was high for the fruit yield, number of fruits per vine, length of fruit and single fruit weight. High heritability coupled with high-to-moderate genetic advance was estimated for all characters studied. Correlation studies revealed that the fruit yield had a significant, positive correlation with the number of fruits per vine, length of fruit and single fruit weight. Importantly, more than 90% of the genotypic total variation was contributed by the characters included in the path analysis. The highest, direct, positive effect was recorded for the number of fruits per vine. The divergence value for cluster analysis indicated that the genotypes from clusters II and III had the highest inter-cluster distance and were expected to provide high heterosis in hybridization and to show wide variability in genetic architecture. The selection of high yielding genotypes should give emphasis to the number of fruits per vine, length of fruit and single fruit weight.

  4. Variability, correlation and path coefficient analysis of seedling traits ...

    African Journals Online (AJOL)

    use

    2011-12-12

    Dec 12, 2011 ... Indirect selection is a useful means for improving yield in cotton crop. The objective of the present study was to determine the genetic variability, broad sense heritability, genetic advance and correlation among the six seedling traits and their direct and indirect effects on cotton yield by using path coefficient ...

  5. Latent variable models an introduction to factor, path, and structural equation analysis

    CERN Document Server

    Loehlin, John C

    2004-01-01

    This fourth edition introduces multiple-latent variable models by utilizing path diagrams to explain the underlying relationships in the models. The book is intended for advanced students and researchers in the areas of social, educational, clinical, ind

  6. Dynamic Path Analysis in Life-Course Epidemiology

    DEFF Research Database (Denmark)

    Gamborg, Michael Orland; Boje Jensen, Gorm; Sørensen, Thorkild I.A.

    2011-01-01

    it works through other risk factors. In this paper, the dynamic path analysis model is presented as a tool to analyze these dynamic mechanisms in life-course epidemiology. A key feature of dynamic path analysis is its ability to decompose the total effect of a risk factor into a direct effect (not mediated...... by other variables) and indirect effects (mediated through other variables). This is illustrated by examining the associations between repeated measurements of body mass index (BMI) and systolic blood pressure (SBP) and the risk of CHD in a sample of Danish men between 1976 and 2006. The effect of baseline...... BMI on the risk of CHD is decomposed into a direct effect and indirect effects going through later BMI, concurrent SBP, or later SBP. In conclusion, dynamic path analysis is a flexible tool that by the decomposition of effects can be used to increase the understanding of mechanisms that underlie...

  7. Interrelationships between morphometric variables and rounded fish body yields evaluated by path analysis

    Directory of Open Access Journals (Sweden)

    Rafael Vilhena Reis Neto

    2012-07-01

    Full Text Available The objective of this study was to verify which morphometric measures and ratios are more directly associated with the weight and body yields of rounded fish. A total of 225 specimens of rounded fish (59 pacus, 61 tambaquis, 52 tambacus and 53 paquis with average weight of 972.43 g (±115.52 g were sampled, stunned, slaughtered, weighed, measured, and processed for morphometric and processing yield analysis. The morphometric measures taken were: standard length (CP; head length (CC; head height (AC; body height (A1; and body width (L1. For completeness, the following morphometric ratios were calculated: CC/CP, AC/CP, A1/CP, L1/CP, CC/A1, AC/A1, L1/A1, CC/AC and L1/CC. The yields of carcass, filet, rib and filet with rib were estimated after processing. Initially, a "stepwise" procedure was performed in order to eliminate multicollinearity problems among the morphometric variables, and the phenotypic correlations were then calculated for the dependent variables (weight and body yields and independent variables (morphometric measurements and ratios. These correlations were later deployed in direct and indirect effects through path analysis, and the direct and indirect contributions of each variable were measured in percentage terms. The CC and A1 measures were important for determining the weight of rounded fish. The CC/A1 ratio was the variable most directly associated with carcass yield. For filet, filet with rib and rib yields, the L1/CC ratio was found to be more appropriate and can be used directly.

  8. Variables As Currency: Linking Meta-Analysis Research and Data Paths in Sciences

    Directory of Open Access Journals (Sweden)

    Hua Qin

    2014-11-01

    Full Text Available Meta-analyses are studies that bring together data or results from multiple independent studies to produce new and over-arching findings. Current data curation systems only partially support meta-analytic research. Some important meta-analytic tasks, such as the selection of relevant studies for review and the integration of research datasets or findings, are not well supported in current data curation systems. To design tools and services that more fully support meta-analyses, we need a better understanding of meta-analytic research. This includes an understanding of both the practices of researchers who perform the analyses and the characteristics of the individual studies that are brought together. In this study, we make an initial contribution to filling this gap by developing a conceptual framework linking meta-analyses with data paths represented in published articles selected for the analysis. The framework focuses on key variables that represent primary/secondary datasets or derived socio-ecological data, contexts of use, and the data transformations that are applied. We introduce the notion of using variables and their relevant information (e.g., metadata and variable relationships as a type of currency to facilitate synthesis of findings across individual studies and leverage larger bodies of relevant source data produced in small science research. Handling variables in this manner provides an equalizing factor between data from otherwise disparate data-producing communities. We conclude with implications for exploring data integration and synthesis issues as well as system development.

  9. A method of signal transmission path analysis for multivariate random processes

    International Nuclear Information System (INIS)

    Oguma, Ritsuo

    1984-04-01

    A method for noise analysis called ''STP (signal transmission path) analysis'' is presentd as a tool to identify noise sources and their propagation paths in multivariate random proceses. Basic idea of the analysis is to identify, via time series analysis, effective network for the signal power transmission among variables in the system and to make use of its information to the noise analysis. In the present paper, we accomplish this through two steps of signal processings; first, we estimate, using noise power contribution analysis, variables which have large contribution to the power spectrum of interest, and then evaluate the STPs for each pair of variables to identify STPs which play significant role for the generated noise to transmit to the variable under evaluation. The latter part of the analysis is executed through comparison of partial coherence function and newly introduced partial noise power contribution function. This paper presents the procedure of the STP analysis and demonstrates, using simulation data as well as Borssele PWR noise data, its effectiveness for investigation of noise generation and propagation mechanisms. (author)

  10. Global Qualitative Flow-Path Modeling for Local State Determination in Simulation and Analysis

    Science.gov (United States)

    Malin, Jane T. (Inventor); Fleming, Land D. (Inventor)

    1998-01-01

    For qualitative modeling and analysis, a general qualitative abstraction of power transmission variables (flow and effort) for elements of flow paths includes information on resistance, net flow, permissible directions of flow, and qualitative potential is discussed. Each type of component model has flow-related variables and an associated internal flow map, connected into an overall flow network of the system. For storage devices, the implicit power transfer to the environment is represented by "virtual" circuits that include an environmental junction. A heterogeneous aggregation method simplifies the path structure. A method determines global flow-path changes during dynamic simulation and analysis, and identifies corresponding local flow state changes that are effects of global configuration changes. Flow-path determination is triggered by any change in a flow-related device variable in a simulation or analysis. Components (path elements) that may be affected are identified, and flow-related attributes favoring flow in the two possible directions are collected for each of them. Next, flow-related attributes are determined for each affected path element, based on possibly conflicting indications of flow direction. Spurious qualitative ambiguities are minimized by using relative magnitudes and permissible directions of flow, and by favoring flow sources over effort sources when comparing flow tendencies. The results are output to local flow states of affected components.

  11. A Path Analysis of Latino Parental, Teenager and Cultural Variables in Teenagers' Sexual Attitudes, Norms, Self-Efficacy, and Sexual Intentions1

    OpenAIRE

    Gaioso, Vanessa Pirani; Villarruel, Antonia Maria; Wilson, Lynda Anne; Azuero, Andres; Childs, Gwendolyn Denice; Davies, Susan Lane

    2015-01-01

    OBJECTIVE: to test a theoretical model based on the Parent-Based Expansion of the Theory of Planned Behavior examining relation between selected parental, teenager and cultural variables and Latino teenagers' intentions to engage in sexual behavior. METHOD: a cross-sectional correlational design based on a secondary data analysis of 130 Latino parent and teenager dyads. RESULTS: regression and path analysis procedures were used to test seven hypotheses and the results demonstrated partial sup...

  12. PATH ANALYSIS OF RECORDING SYSTEM INNOVATION FACTORS AFFECTING ADOPTION OF GOAT FARMERS

    Directory of Open Access Journals (Sweden)

    S. Okkyla

    2014-09-01

    Full Text Available The objective of this study was to evaluate the path analysis of recording system innovation factorsaffecting adoption of goat farmers. This study was conducted from January to February 2014 inPringapus District, Semarang Regency by using survey method. For determining the location, this studyused purposive sampling method. The amount of respondents were determined by quota samplingmethod. Total respondents randomly chosed were 146 farmers. The data were descriptively andquantitatively analyzed by using path analysis of statistical package for the social science (SPSS 16.Independent variables in this study were internal factor, motivation, innovation characteristics,information source, and dependent variable was adoption. Analysis of linear regression showed thatthere was no significant effect of internal factor on adoption, so that it was important to use the trimmingmethod in path analysis. The result of path analysis showed that the influence of motivation, innovationcharacteristics and information source on adoption were 0.168; 0.720 and 0.09, respectively. Innovationcharacteristics were the greatest effect on adoption. In conclusion, by improving innovationcharacteristics of respondent through motivation and information source may significantly increase theadoption of recording system in goat farmers.

  13. a Latent Variable Path Analysis Model of Secondary Physics Enrollments in New York State.

    Science.gov (United States)

    Sobolewski, Stanley John

    The Percentage of Enrollment in Physics (PEP) at the secondary level nationally has been approximately 20% for the past few decades. For a more scientifically literate citizenry as well as specialists to continue scientific research and development, it is desirable that more students enroll in physics. Some of the predictor variables for physics enrollment and physics achievement that have been identified previously includes a community's socioeconomic status, the availability of physics, the sex of the student, the curriculum, as well as teacher and student data. This study isolated and identified predictor variables for PEP of secondary schools in New York. Data gathered by the State Education Department for the 1990-1991 school year was used. The source of this data included surveys completed by teachers and administrators on student characteristics and school facilities. A data analysis similar to that done by Bryant (1974) was conducted to determine if the relationships between a set of predictor variables related to physics enrollment had changed in the past 20 years. Variables which were isolated included: community, facilities, teacher experience, number of type of science courses, school size and school science facilities. When these variables were isolated, latent variable path diagrams were proposed and verified by the Linear Structural Relations computer modeling program (LISREL). These diagrams differed from those developed by Bryant in that there were more manifest variables used which included achievement scores in the form of Regents exam results. Two criterion variables were used, percentage of students enrolled in physics (PEP) and percent of students enrolled passing the Regents physics exam (PPP). The first model treated school and community level variables as exogenous while the second model treated only the community level variables as exogenous. The goodness of fit indices for the models was 0.77 for the first model and 0.83 for the second

  14. Genetic Variability, Correlation Studies and Path Coefficient Analysis in Gladiolus Alatus Cultivars

    International Nuclear Information System (INIS)

    Ramzan, A.; Nawab, N. N.; Tariq, M. S.; Ikram, S.; Ahad, A.

    2016-01-01

    A study was undertaken to find out the estimates of genetic variability, genetic parameters and character association among different flower traits between three gladiolus cultivars viz: Sancerre, Fado and Advanced Red. The experiment was repeated three times by using RCBD (Randomized complete block design) at Department of Horticulture, PMAS-UAAR, Rawalpindi. The highest genotypic coefficient variation (GCV) and phenotypic coefficient variation (PCV) magnitude was observed for spike length (16.00) and number of florets per spike (14.84) followed by number of leaves (10.00). Among the traits studied the highest heritability estimates was recorded in spike length (99.5 percent) followed by number of florets/spike (99.6 percent) and lowest in plant height (98.2 percent). The genetic advance as percent of mean was ranged from 2.8 percent to 24.75 percent. Genetic advance was highest for floret breadth (24.75 percent) and lowest for plant height (2.8 percent). High heritability combined with high genetic advance was noticed for number of florets per spike, spike length and floret breadth indicating additive gene action which suggested that improvement of these traits would be effective for further selection of superior genotypes. Plant height and number of florets per spike showed highly positive and significant association with spike length, number of leaves, leaf area, floret length and floret breadth while, spike length registered positive and significant correlation with number of leaves and floret breadth. The path coefficient analysis based on spike length, as responsible variable exposed that all of the traits exerted direct positive effect except leaf area and floret length. Spike length imparted maximum positive direct effect on the number of florets per spike. Hence, spike length and number of florets per spike may be considered for further improvement. However, Floret length and floret breadth may also be considered as a criterion for selection. (author)

  15. Generalized Path Analysis and Generalized Simultaneous Equations Model for Recursive Systems with Responses of Mixed Types

    Science.gov (United States)

    Tsai, Tien-Lung; Shau, Wen-Yi; Hu, Fu-Chang

    2006-01-01

    This article generalizes linear path analysis (PA) and simultaneous equations models (SiEM) to deal with mixed responses of different types in a recursive or triangular system. An efficient instrumental variable (IV) method for estimating the structural coefficients of a 2-equation partially recursive generalized path analysis (GPA) model and…

  16. Genetic variability, correlation and path coefficients of yield and its components analysis in pumpkin (Cucurbita moschata Duch Ex Poir

    Directory of Open Access Journals (Sweden)

    GM Mohsin

    2017-06-01

    Full Text Available Genetic variability, correlation and path coefficient were studied for yield and yield component traits in twenty one diverse genotypes of pumpkin. Highest genotypic coefficient of variation was recorded for fruit length (cm, single fruit weight (kg, Brix (% and yield per plant (kg. Heritability estimates in broad sense were higher for almost all the characters. The characters namely, fruit length, single fruit weight, yield per plant and brix% had high genotypic coefficient of variation coupled with heritability gave high genetic advance expressed as percentage of mean ranged from 76.84 to 96.06 which indicated that these characters were less influenced by environment confirming additive gene action, and therefore, selection of these characters would be more effective for yield improvement of pumpkins. Total six traits likely fruit length, fruit diameter, flesh thickness, single fruit weight and number of fruits per plant were positively and significantly associated with yield per plant. Path coefficient analysis also revealed maximum contribution of single fruit weight (0.869 to yield and this was followed by the contribution of number of fruit per plant (0.527 at genotypic level.

  17. Explaining Technology Integration in K-12 Classrooms: A Multilevel Path Analysis Model

    Science.gov (United States)

    Liu, Feng; Ritzhaupt, Albert D.; Dawson, Kara; Barron, Ann E.

    2017-01-01

    The purpose of this research was to design and test a model of classroom technology integration in the context of K-12 schools. The proposed multilevel path analysis model includes teacher, contextual, and school related variables on a teacher's use of technology and confidence and comfort using technology as mediators of classroom technology…

  18. Measurement of variable magnetic reversal paths in electrically contacted pseudo-spin-valve rings

    International Nuclear Information System (INIS)

    Hayward, T J; Llandro, J; Schackert, F D O; Morecroft, D; Balsod, R B; Bland, J A C; Castano, F J; Ross, C A

    2007-01-01

    In this work we show that the measurement of single magnetic reversal events is of critical importance in order to correctly characterize the switching of magnetic microstructures. Magnetoresistance measurements are performed on two pseudo-spin-valve ring structures with high enough signal to noise to allow the probing of single reversal events. Using this technique we acquire 'switching spectra' which demonstrate that the rings exhibit a range of variable reversal paths, including a bistable reversal mechanism of the hard layer, where the two switching routes have substantially different switching fields. The signature of the variable reversal paths would have been obscured in field cycle averaged data and in the bistable case would cause a fundamental misinterpretation of the reversal behaviour

  19. Acquisition Path Analysis as a Collaborative Activity

    International Nuclear Information System (INIS)

    Nakao, A.; Grundule, R.; Gushchyn, K.; El Gebaly, A.; Higgy, R.; Tsvetkov, I.; Mandl, W.

    2015-01-01

    In the International Atomic Energy Agency, acquisition path analysis (APA) is indispensable to safeguards implementation. It is an integral part of both State evaluation process and the development of State level safeguards approaches, all performed through ongoing collaborative analysis of all available safeguards relevant information by State evaluation groups (SEG) with participation of other contributors, as required. To perform comprehensive State evaluation, to develop and revise State-level safeguards approaches, and to prepare annual implementation plans, the SEG in its collaborative analysis follows accepted safeguards methodology and guidance. In particular, the guide ''Performing Acquisition Path Analysis for the Development of a State-level Safeguards Approach for a State with a CSA'' is used. This guide identifies four major steps of the APA process: 1. Consolidating information about the State's past, present and planned nuclear fuel cycle-related capabilities and infrastructure; 2. Identifying and visually presenting technically plausible acquisition paths for the State; 3. Assessing acquisition path steps (State's technical capabilities and possible actions) along the identified acquisition paths; and 4. Assessing the time needed to accomplish each identified technically plausible acquisition path for the State. The paper reports on SEG members' and other contributors' experience with APA when following the above steps, including the identification of plausible acquisition pathways, estimation of time frames for all identified steps and determination of the time needed to accomplish each acquisition path. The difficulties that the SEG encountered during the process of performing the APA are also addressed. Feedback in the form of practical suggestions for improving the clarity of the acquisition path step assessment forms and a proposal for software support are also included. (author)

  20. Study of Self Medication In Patients With Diabetes Using Path Analysis

    Directory of Open Access Journals (Sweden)

    M Rezaei

    2015-01-01

    Full Text Available Self-medication is a behavior in which one tries to solve his/her health condition or problem without professional help. With regard to mortality and severe complications of diabetes, inappropriate self- medication can have severe consequences but proper planning can control this behavior to improve the patient′s health. In this study, the effect of each factor on self-medication in patients with diabetes is determined using path analysis technique. This cross-sectional study was conducted in the Kermanshah diabetes center. The number of patients with diabetes interviewed were 500. Each patient′s score of self-medication were determined according to a questionnaire, with a higher score showing greater self-medication. Demographic information and scores of trust to doctors, medical expenses, others′ recommendations and busy work environment as predictor variables were measured and analyzed using SPSS 16.0. Based on the questionnaire scores, two patients (0.4% largely, 191 (38.7% moderately and 300 (60.9% slightly were on self-medication. The variable; mistrust of doctors only directly, variables; age, the duration of diabetes and family history of heart disease only indirectly and variables; busy work environment, medical expenses, others′ recommendations and family history of hypertension directly and indirectly were related to self-medication. The results of this study showed that more than 60% of patients with diabetes had low self-medication, which represents the success of education principles and methods. Extracting causal relationships among the complexity of factors influencing a disease requires powerful statistical tools such as path analysis.

  1. A taxonomy of integral reaction path analysis

    Energy Technology Data Exchange (ETDEWEB)

    Grcar, Joseph F.; Day, Marcus S.; Bell, John B.

    2004-12-23

    W. C. Gardiner observed that achieving understanding through combustion modeling is limited by the ability to recognize the implications of what has been computed and to draw conclusions about the elementary steps underlying the reaction mechanism. This difficulty can be overcome in part by making better use of reaction path analysis in the context of multidimensional flame simulations. Following a survey of current practice, an integral reaction flux is formulated in terms of conserved scalars that can be calculated in a fully automated way. Conditional analyses are then introduced, and a taxonomy for bidirectional path analysis is explored. Many examples illustrate the resulting path analysis and uncover some new results about nonpremixed methane-air laminar jets.

  2. Factors associated with motivation in medical education: a path analysis.

    Science.gov (United States)

    Kunanitthaworn, Natchaya; Wongpakaran, Tinakon; Wongpakaran, Nahathai; Paiboonsithiwong, Salilthip; Songtrijuck, Natchaphon; Kuntawong, Pimolpun; Wedding, Danny

    2018-06-18

    This study identified and investigated the relationship between demographics, mental health problems, positive personality traits and perceived social support and motivation in medical education (MME) among first year medical students. One hundred-thirty eight first year medical students completed the Academic Motivation Scale, Outcome Inventory, Strength Based Inventory, and Multidimensional Scale for Perceived Social Support. Path analysis was conducted to identify relationships between the variables of interest and each type of motivation, including intrinsic and extrinsic motivation and amotivation. The mean age of the sample was 18.86 ± 0.74 and 60% of the subjects were female. Path analysis showed that extrinsic motivation was positively associated with being female, personal choice for studying medicine, and grade point average at high school. Intrinsic motivation was correlated with perceived family support, personal choice for studying medicine and the positive attribute of determination. Amotivation was related to being male, personal choice, and depression. While both extrinsic and intrinsic motivation were correlated, they were uncorrelated with amotivation. All variables accounted for 18, 13, and 45% of variance of intrinsic motivation, extrinsic motivation and amotivation, respectively. Each type of motivation has different but related predictors. Extrinsic and intrinsic motivation can be promoted, whereas amotivation represents an exclusive issue, one related more to depression, that needs to be reduced to not interfere with academic achievement and quality of life of medical students.

  3. A Key Event Path Analysis Approach for Integrated Systems

    Directory of Open Access Journals (Sweden)

    Jingjing Liao

    2012-01-01

    Full Text Available By studying the key event paths of probabilistic event structure graphs (PESGs, a key event path analysis approach for integrated system models is proposed. According to translation rules concluded from integrated system architecture descriptions, the corresponding PESGs are constructed from the colored Petri Net (CPN models. Then the definitions of cycle event paths, sequence event paths, and key event paths are given. Whereafter based on the statistic results after the simulation of CPN models, key event paths are found out by the sensitive analysis approach. This approach focuses on the logic structures of CPN models, which is reliable and could be the basis of structured analysis for discrete event systems. An example of radar model is given to characterize the application of this approach, and the results are worthy of trust.

  4. Two-condition within-participant statistical mediation analysis: A path-analytic framework.

    Science.gov (United States)

    Montoya, Amanda K; Hayes, Andrew F

    2017-03-01

    Researchers interested in testing mediation often use designs where participants are measured on a dependent variable Y and a mediator M in both of 2 different circumstances. The dominant approach to assessing mediation in such a design, proposed by Judd, Kenny, and McClelland (2001), relies on a series of hypothesis tests about components of the mediation model and is not based on an estimate of or formal inference about the indirect effect. In this article we recast Judd et al.'s approach in the path-analytic framework that is now commonly used in between-participant mediation analysis. By so doing, it is apparent how to estimate the indirect effect of a within-participant manipulation on some outcome through a mediator as the product of paths of influence. This path-analytic approach eliminates the need for discrete hypothesis tests about components of the model to support a claim of mediation, as Judd et al.'s method requires, because it relies only on an inference about the product of paths-the indirect effect. We generalize methods of inference for the indirect effect widely used in between-participant designs to this within-participant version of mediation analysis, including bootstrap confidence intervals and Monte Carlo confidence intervals. Using this path-analytic approach, we extend the method to models with multiple mediators operating in parallel and serially and discuss the comparison of indirect effects in these more complex models. We offer macros and code for SPSS, SAS, and Mplus that conduct these analyses. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  5. DiversePathsJ: diverse shortest paths for bioimage analysis.

    Science.gov (United States)

    Uhlmann, Virginie; Haubold, Carsten; Hamprecht, Fred A; Unser, Michael

    2018-02-01

    We introduce a formulation for the general task of finding diverse shortest paths between two end-points. Our approach is not linked to a specific biological problem and can be applied to a large variety of images thanks to its generic implementation as a user-friendly ImageJ/Fiji plugin. It relies on the introduction of additional layers in a Viterbi path graph, which requires slight modifications to the standard Viterbi algorithm rules. This layered graph construction allows for the specification of various constraints imposing diversity between solutions. The software allows obtaining a collection of diverse shortest paths under some user-defined constraints through a convenient and user-friendly interface. It can be used alone or be integrated into larger image analysis pipelines. http://bigwww.epfl.ch/algorithms/diversepathsj. michael.unser@epfl.ch or fred.hamprecht@iwr.uni-heidelberg.de. Supplementary data are available at Bioinformatics online. © The Author(s) 2017. Published by Oxford University Press.

  6. Genotypic Variability of the Components and their Effects on the Rice Yield: Correlation and Path Analysis Study

    Directory of Open Access Journals (Sweden)

    Sharkhawat Hossain

    2008-06-01

    Full Text Available Twenty modern Boro rice varieties were evaluated with a view to find variability and genetic association for grain yield and yield components characters. Genotypic and Phenotypic correlation among these characters were computed. Both genotypic and phenotypic correlation coefficients were significant between plant height and number of effective tillers per plant followed by panicle length. There was a positive significant correlation between yield and number of effective tillers per plant followed by percent filled grain per panicle. Path coefficient showed that number of effective tiller per plant and plant height are the characters that contribute largely to grain yield.

  7. The efficiency of parameter estimation of latent path analysis using summated rating scale (SRS) and method of successive interval (MSI) for transformation of score to scale

    Science.gov (United States)

    Solimun, Fernandes, Adji Achmad Rinaldo; Arisoesilaningsih, Endang

    2017-12-01

    Research in various fields generally investigates systems and involves latent variables. One method to analyze the model representing the system is path analysis. The data of latent variables measured using questionnaires by applying attitude scale model yields data in the form of score, before analyzed should be transformation so that it becomes data of scale. Path coefficient, is parameter estimator, calculated from scale data using method of successive interval (MSI) and summated rating scale (SRS). In this research will be identifying which data transformation method is better. Path coefficients have smaller varieties are said to be more efficient. The transformation method that produces scaled data and used in path analysis capable of producing path coefficients (parameter estimators) with smaller varieties is said to be better. The result of analysis using real data shows that on the influence of Attitude variable to Intention Entrepreneurship, has relative efficiency (ER) = 1, where it shows that the result of analysis using data transformation of MSI and SRS as efficient. On the other hand, for simulation data, at high correlation between items (0.7-0.9), MSI method is more efficient 1.3 times better than SRS method.

  8. Path modeling and process control

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar; Rodionova, O.; Pomerantsev, A.

    2007-01-01

    and having three or more stages. The methods are applied to a process control of a multi-stage production process having 25 variables and one output variable. When moving along the process, variables change their roles. It is shown how the methods of path modeling can be applied to estimate variables...... be performed regarding the foreseeable output property y, and with respect to an admissible range of correcting actions for the parameters of the next stage. In this paper the basic principles of path modeling is presented. The mathematics is presented for processes having only one stage, having two stages...... of the next stage with the purpose of obtaining optimal or almost optimal quality of the output variable. An important aspect of the methods presented is the possibility of extensive graphic analysis of data that can provide the engineer with a detailed view of the multi-variate variation in data....

  9. A path analysis model for explaining unsafe behavior in workplaces: the effect of perceived work pressure.

    Science.gov (United States)

    Ghasemi, Fakhradin; Kalatpour, Omid; Moghimbeigi, Abbas; Mohhamadfam, Iraj

    2018-06-01

    Unsafe behavior is closely related to occupational accidents. Work pressure is one the main factors affecting employees' behavior. The aim of the present study was to provide a path analysis model for explaining how work pressure affects safety behavior. Using a self-administered questionnaire, six variables supposed to affect safety employees' behavior were measured. The path analysis model was constructed based on several hypotheses. The goodness of fit of the model was assessed using both absolute and comparative fit indices. Work pressure was determined not to influence safety behavior directly. However, it negatively influenced other variables. Group attitude and personal attitude toward safety were the main factors mediating the effect of work pressure on safety behavior. Among the variables investigated in the present study, group attitude, personal attitude and work pressure had the strongest effects on safety behavior. Managers should consider that in order to improve employees' safety behavior, work pressure should be reduced to a reasonable level, and concurrently a supportive environment, which ensures a positive group attitude toward safety, should be provided. Replication of the study is recommended.

  10. Social network analysis using k-Path centrality method

    Science.gov (United States)

    Taniarza, Natya; Adiwijaya; Maharani, Warih

    2018-03-01

    k-Path centrality is deemed as one of the effective methods to be applied in centrality measurement in which the influential node is estimated as the node that is being passed by information path frequently. Regarding this, k-Path centrality has been employed in the analysis of this paper specifically by adapting random-algorithm approach in order to: (1) determine the influential user’s ranking in a social media Twitter; and (2) ascertain the influence of parameter α in the numeration of k-Path centrality. According to the analysis, the findings showed that the method of k-Path centrality with random-algorithm approach can be used to determine user’s ranking which influences in the dissemination of information in Twitter. Furthermore, the findings also showed that parameter α influenced the duration and the ranking results: the less the α value, the longer the duration, yet the ranking results were more stable.

  11. An Introduction to Path Analysis

    Science.gov (United States)

    Wolfe, Lee M.

    1977-01-01

    The analytical procedure of path analysis is described in terms of its use in nonexperimental settings in the social sciences. The description assumes a moderate statistical background on the part of the reader. (JKS)

  12. Diversion Path Analysis Handbook. Volume 1. Methodology

    International Nuclear Information System (INIS)

    Goodwin, K.E.; Schleter, J.C.; Maltese, M.D.K.

    1978-11-01

    Diversion Path Analysis (DPA) is a safeguards evaluation tool which is used to determine the vulnerability of the Material Control and Material Accounting (MC and MA) Subsystems to the threat of theft of Special Nuclear Material (SNM) by a knowledgeable Insider. The DPA team should consist of two individuals who have technical backgrounds. The implementation of DPA is divided into five basic steps: Information and Data Gathering, Process Characterization, Analysis of Diversion Paths, Results and Findings, and Documentation

  13. A Path Analysis of Latino Parental, Teenager and Cultural Variables in Teenagers' Sexual Attitudes, Norms, Self-Efficacy, and Sexual Intentions.

    Science.gov (United States)

    Gaioso, Vanessa Pirani; Villarruel, Antonia Maria; Wilson, Lynda Anne; Azuero, Andres; Childs, Gwendolyn Denice; Davies, Susan Lane

    2015-01-01

    to test a theoretical model based on the Parent-Based Expansion of the Theory of Planned Behavior examining relation between selected parental, teenager and cultural variables and Latino teenagers' intentions to engage in sexual behavior. a cross-sectional correlational design based on a secondary data analysis of 130 Latino parent and teenager dyads. regression and path analysis procedures were used to test seven hypotheses and the results demonstrated partial support for the model. Parent familism and knowledge about sex were significantly associated with parents' attitudes toward sexual communication with their teenagers. Parent Latino acculturation was negatively associated with parents' self-efficacy toward sexual communication with their teenagers and positevely associated with parents' subjective norms toward sexual communication with their teenagers. Teenager knowledge about sex was significantly associated with higher levels of teenagers' attitudes and subjective norms about sexual communication with parents. Only the predictor of teenagers' attitudes toward having sex in the next 3 months was significantly associated with teenagers' intentions to have sex in the next 3 months. the results of this study provide important information to guide future research that can inform development of interventions to prevent risky teenager sexual behavior among Latinos.

  14. A Path Analysis Model Pertinent to Undergraduates' Academic Success: Examining Academic Confidence, Psychological Capital and Academic Coping Factors

    Science.gov (United States)

    Kirikkanat, Berke; Soyer, Makbule Kali

    2018-01-01

    The major purpose of this study was to create a path analysis model of academic success in a group of university students, which included the variables of academic confidence and psychological capital with a mediator variable--academic coping. 400 undergraduates from Marmara University and Istanbul Commerce University who were in sophomore, junior…

  15. Path analysis for selection of feijoa with greater pulp weight

    Directory of Open Access Journals (Sweden)

    Joel Donazzolo

    Full Text Available ABSTRACT: The objective of this paper was to identify the direct and indirect effects of feijoa fruits (Acca sellowiana traitson pulp weight, in order to use these traits in indirect genotypes selection. Fruits of five feijoa plants were collected in Rio Grande do Sul, in the years of 2009, 2010 and 2011. Six traits were evaluated: diameter, length, total weight, pulp weight, peel thickness and number of seeds per fruit. In the path analysis, with or without ridge regression, pulp weight was considered as the basic variable, and the other traits were considered as explanatory variables. Total weight and fruit diameter had high direct effect, and are the main traits associated with pulp weight. These traits may serve as criteria for indirect selection to increase feijoa pulp weight, since they are easy to be measured.

  16. Path Analysis of Grain Yield and Yield Components and Some Agronomic Traits in Bread Wheat

    Directory of Open Access Journals (Sweden)

    Mohsen Janmohammadi

    2014-01-01

    Full Text Available Development of new bread wheat cultivars needs efficient tools to monitor trait association in a breeding program. This investigation was aimed to characterize grain yield components and some agronomic traits related to bread wheat grain yield. The efficiency of a breeding program depends mainly on the direction of the correlation between different traits and the relative importance of each component involved in contributing to grain yield. Correlation and path analysis were carried out in 56 bread wheat genotypes grown under field conditions of Maragheh, Iran. Observations were recorded on 18 wheat traits and correlation coefficient analysis revealed grain yield was positively correlated with stem diameter, spike length, floret number, spikelet number, grain diameter, grain length and 1000 seed weight traits. According to the variance inflation factor (VIF and tolerance as multicollinearity statistics, there are inconsistent relationships among the variables and all traits could be considered as first-order variables (Model I with grain yield as the response variable due to low multicollinearity of all measured traits. In the path coefficient analysis, grain yield represented the dependent variable and the spikelet number and 1000 seed weight traits were the independent ones. Our results indicated that the number of spikelets per spikes and leaf width and 1000 seed weight traits followed by the grain length, grain diameter and grain number per spike were the traits related to higher grain yield. The above mentioned traits along with their indirect causal factors should be considered simultaneously as an effective selection criteria evolving high yielding genotype because of their direct positive contribution to grain yield.

  17. Sequential Path Model for Grain Yield in Soybean

    Directory of Open Access Journals (Sweden)

    Mohammad SEDGHI

    2010-09-01

    Full Text Available This study was performed to determine some physiological traits that affect soybean,s grain yield via sequential path analysis. In a factorial experiment, two cultivars (Harcor and Williams were sown under four levels of nitrogen and two levels of weed management at the research station of Tabriz University, Iran, during 2004 and 2005. Grain yield, some yield components and physiological traits were measured. Correlation coefficient analysis showed that grain yield had significant positive and negative association with measured traits. A sequential path analysis was done in order to evaluate associations among grain yield and related traits by ordering the various variables in first, second and third order paths on the basis of their maximum direct effects and minimal collinearity. Two first-order variables, namely number of pods per plant and pre-flowering net photosynthesis revealed highest direct effect on total grain yield and explained 49, 44 and 47 % of the variation in grain yield based on 2004, 2005, and combined datasets, respectively. Four traits i.e. post-flowering net photosynthesis, plant height, leaf area index and intercepted radiation at the bottom layer of canopy were found to fit as second-order variables. Pre- and post-flowering chlorophyll content, main root length and intercepted radiation at the middle layer of canopy were placed at the third-order path. From the results concluded that, number of pods per plant and pre-flowering net photosynthesis are the best selection criteria in soybean for grain yield.

  18. A Path Analysis of Latino Parental, Teenager and Cultural Variables in Teenagers' Sexual Attitudes, Norms, Self-Efficacy, and Sexual Intentions

    Directory of Open Access Journals (Sweden)

    Vanessa Pirani Gaioso

    2015-06-01

    Full Text Available OBJECTIVE: to test a theoretical model based on the Parent-Based Expansion of the Theory of Planned Behavior examining relation between selected parental, teenager and cultural variables and Latino teenagers' intentions to engage in sexual behavior.METHOD: a cross-sectional correlational design based on a secondary data analysis of 130 Latino parent and teenager dyads.RESULTS: regression and path analysis procedures were used to test seven hypotheses and the results demonstrated partial support for the model. Parent familism and knowledge about sex were significantly associated with parents' attitudes toward sexual communication with their teenagers. Parent Latino acculturation was negatively associated with parents' self-efficacy toward sexual communication with their teenagers and positevely associated with parents' subjective norms toward sexual communication with their teenagers. Teenager knowledge about sex was significantly associated with higher levels of teenagers' attitudes and subjective norms about sexual communication with parents. Only the predictor of teenagers' attitudes toward having sex in the next 3 months was significantly associated with teenagers' intentions to have sex in the next 3 months.CONCLUSION: the results of this study provide important information to guide future research that can inform development of interventions to prevent risky teenager sexual behavior among Latinos.

  19. A moderated mediated path analysis of factors influencing student performance on a standardized high-stakes science test

    Science.gov (United States)

    Pelkey, Ramona K.

    Gender, ethnicity, family economic status, reading score, mathematics score, and number of science semesters successfully completed were examined for their contributory role to a student's science score on a high-stakes, high school exit examination. Path analysis and analysis of variance procedures were used to quantify each variable's influence on science score. Gender, ethnicity, and family economic status were found to be moderators while reading proved to mediate within the model. The path model was created using a calibration sample and cross-validated using a hold-out validation sample. Bootstrapping was used to verify the goodness of fit of the model. A predictive equation explained 66% (R2 = .66) of the variance in observed TAKS science score.

  20. Stage-by-Stage and Parallel Flow Path Compressor Modeling for a Variable Cycle Engine

    Science.gov (United States)

    Kopasakis, George; Connolly, Joseph W.; Cheng, Larry

    2015-01-01

    This paper covers the development of stage-by-stage and parallel flow path compressor modeling approaches for a Variable Cycle Engine. The stage-by-stage compressor modeling approach is an extension of a technique for lumped volume dynamics and performance characteristic modeling. It was developed to improve the accuracy of axial compressor dynamics over lumped volume dynamics modeling. The stage-by-stage compressor model presented here is formulated into a parallel flow path model that includes both axial and rotational dynamics. This is done to enable the study of compressor and propulsion system dynamic performance under flow distortion conditions. The approaches utilized here are generic and should be applicable for the modeling of any axial flow compressor design.

  1. Sequential Path Analysis for Determination of Relationship Between Yield and Yield Components in Bread Wheat (Triticum aestivum.L.

    Directory of Open Access Journals (Sweden)

    Mohtasham MOHAMMADI

    2014-03-01

    Full Text Available An experiment was conducted to evaluate 295 wheat genotypes in Alpha-Lattice design with two replications. The arithmetic mean and standard deviation of grain yield was 2706 and 950 (kg/ha,respectively. The results of correlation coefficients indicated that grain yield had significant and positive association with plant height, spike length, early growth vigor and agronomic score. Whereas there were negative correlation coefficients between grain yield and days to physiological maturity and canopy temperature before and during anthesis. Path analysis indicated agronomic score and plant height had high positive direct effects on grain yield, while canopy temperature before and during anthesis, and days to maturity, wes another trait having negative direct effect on grain yield. The results of sequential path analysis showed the traits that accounted as a criteria variable for high grain yield were agronomic score, plant height, canopy temperature, spike length, chlorophyll content and early growth vigor, which were determined as first, second and third order variables and had strong effects on grain yield via one or more paths. More important, as canopy temperature, agronomic score and early growth vigor can be evaluated quickly and easily, these traits may be used for evaluation of large populations.

  2. Creep analysis by the path function method

    International Nuclear Information System (INIS)

    Akin, J.E.; Pardue, R.M.

    1977-01-01

    The finite element method has become a common analysis procedure for the creep analysis of structures. The most recent programs are designed to handle a general class of material properties and are able to calculate elastic, plastic, and creep components of strain under general loading histories. The constant stress approach is too crude a model to accurately represent the actual behaviour of the stress for large time steps. The true path of a point in the effective stress-effective strain (sigmasup(e)-epsilonsup(c)) plane is often one in which the slope is rapidly changing. Thus the stress level quickly moves away from the initial stress level and then gradually approaches the final one. The result is that the assumed constant stress level quickly becomes inaccurate. What is required is a better method of approximation of the true path in the sigmasup(e)-epsilonsup(c) space. The method described here is called the path function approach because it employs an assumed function to estimate the motion of points in the sigmasup(e)-epsilonsup(c) space. (Auth.)

  3. Correlates of Unwanted Births in Bangladesh: A Study through Path Analysis.

    Science.gov (United States)

    Roy, Tapan Kumar; Singh, Brijesh P

    2016-01-01

    Unwanted birth is an important public health concern due to its negative association with adverse outcomes of mothers and children as well as socioeconomic development of a country. Although a number of studies have been investigated the determinants of unwanted births through logistic regression analysis, an extensive assessment using path model is lacking. In the current study, we applied path analysis to know the important covariates for unwanted births in Bangladesh. The study used data extracted from Bangladesh Demographic and Health Survey (BDHS) 2011. It considered sub-sample consisted of 7,972 women who had given most recent births five years preceding the date of interview or who were currently pregnant at survey time. Correlation analysis was used to find out the significant association with unwanted births. This study provided the factors affecting unwanted births in Bangladesh. The path model was used to determine the direct, indirect and total effects of socio-demographic factors on unwanted births. The result exhibited that more than one-tenth of the recent births were unwanted in Bangladesh. The differentials of unwanted births were women's age, education, age at marriage, religion, socioeconomic status, exposure of mass-media and use of family planning. In correlation analysis, it showed that unwanted births were positively correlated with women age and place of residence and these relationships were significant. On the contrary, unwanted births were inversely significantly correlated with education and social status. The total effects of endogenous variables such as women age, place of residence and use of family planning methods had favorable effect on unwanted births. Policymakers and program planners need to design programs and services carefully to reduce unwanted births in Bangladesh, especially, service should focus on helping those groups of women who were identified in the analysis as being at increased risks of unwanted births- older women

  4. Correlates of Unwanted Births in Bangladesh: A Study through Path Analysis.

    Directory of Open Access Journals (Sweden)

    Tapan Kumar Roy

    Full Text Available Unwanted birth is an important public health concern due to its negative association with adverse outcomes of mothers and children as well as socioeconomic development of a country. Although a number of studies have been investigated the determinants of unwanted births through logistic regression analysis, an extensive assessment using path model is lacking. In the current study, we applied path analysis to know the important covariates for unwanted births in Bangladesh.The study used data extracted from Bangladesh Demographic and Health Survey (BDHS 2011. It considered sub-sample consisted of 7,972 women who had given most recent births five years preceding the date of interview or who were currently pregnant at survey time. Correlation analysis was used to find out the significant association with unwanted births. This study provided the factors affecting unwanted births in Bangladesh. The path model was used to determine the direct, indirect and total effects of socio-demographic factors on unwanted births.The result exhibited that more than one-tenth of the recent births were unwanted in Bangladesh. The differentials of unwanted births were women's age, education, age at marriage, religion, socioeconomic status, exposure of mass-media and use of family planning. In correlation analysis, it showed that unwanted births were positively correlated with women age and place of residence and these relationships were significant. On the contrary, unwanted births were inversely significantly correlated with education and social status. The total effects of endogenous variables such as women age, place of residence and use of family planning methods had favorable effect on unwanted births.Policymakers and program planners need to design programs and services carefully to reduce unwanted births in Bangladesh, especially, service should focus on helping those groups of women who were identified in the analysis as being at increased risks of unwanted

  5. Logistic Regression and Path Analysis Method to Analyze Factors influencing Students’ Achievement

    Science.gov (United States)

    Noeryanti, N.; Suryowati, K.; Setyawan, Y.; Aulia, R. R.

    2018-04-01

    Students' academic achievement cannot be separated from the influence of two factors namely internal and external factors. The first factors of the student (internal factors) consist of intelligence (X1), health (X2), interest (X3), and motivation of students (X4). The external factors consist of family environment (X5), school environment (X6), and society environment (X7). The objects of this research are eighth grade students of the school year 2016/2017 at SMPN 1 Jiwan Madiun sampled by using simple random sampling. Primary data are obtained by distributing questionnaires. The method used in this study is binary logistic regression analysis that aims to identify internal and external factors that affect student’s achievement and how the trends of them. Path Analysis was used to determine the factors that influence directly, indirectly or totally on student’s achievement. Based on the results of binary logistic regression, variables that affect student’s achievement are interest and motivation. And based on the results obtained by path analysis, factors that have a direct impact on student’s achievement are students’ interest (59%) and students’ motivation (27%). While the factors that have indirect influences on students’ achievement, are family environment (97%) and school environment (37).

  6. [Path analysis of lifestyle habits to the metabolic syndrome].

    Science.gov (United States)

    Zhu, Zhen-xin; Zhang, Cheng-qi; Tang, Fang; Song, Xin-hong; Xue, Fu-zhong

    2013-04-01

    To evaluate the relationship between lifestyle habits and the components of metabolic syndrome (MS). Based on the routine health check-up system in a certain Center for Health Management of Shandong Province, a longitudinal surveillance health check-up cohort from 2005 to 2010 was set up. There were 13 225 urban workers in Jinan included in the analysis. The content of the survey included demographic information, medical history, lifestyle habits, body mass index (BMI) and the level of blood pressure, fasting blood-glucose, and blood lipid, etc. The distribution of BMI, blood pressure, fasting blood-glucose, blood lipid and lifestyle habits between MS patients and non-MS population was compared, latent variables were extracted by exploratory factor analysis to determine the structure model, and then a partial least squares path model was constructed between lifestyle habits and the components of MS. Participants'age was (46.62 ± 12.16) years old. The overall prevalence of the MS was 22.43% (2967/13 225), 26.49% (2535/9570) in males and 11.82% (432/3655) in females. The prevalence of the MS was statistically different between males and females (χ(2) = 327.08, P alcohol consumption has statistical difference (χ(2) = 374.22, P smoking status was statistically significant (χ(2) = 115.86, P smoking was 59.72% (1772/2967), 6.24% (185/2967), 34.04% (1010/2967) respectively, while in non-MS population was 70.03% (7184/10 258), 5.35% (549/10 258), 24.61% (2525/10 258) respectively. Both lifestyle habits and the components of MS were attributable to only one latent variable. After adjustment for age and gender, the path coefficient between the latent component of lifestyle habits and the latent component of MS was 0.22 with statistical significance (t = 6.46, P Unhealthy lifestyle habits are closely related to MS. Meat diet, excessive drinking and smoking are risk factors for MS.

  7. Adaptive enhanced sampling with a path-variable for the simulation of protein folding and aggregation

    Science.gov (United States)

    Peter, Emanuel K.

    2017-12-01

    In this article, we present a novel adaptive enhanced sampling molecular dynamics (MD) method for the accelerated simulation of protein folding and aggregation. We introduce a path-variable L based on the un-biased momenta p and displacements dq for the definition of the bias s applied to the system and derive 3 algorithms: general adaptive bias MD, adaptive path-sampling, and a hybrid method which combines the first 2 methodologies. Through the analysis of the correlations between the bias and the un-biased gradient in the system, we find that the hybrid methodology leads to an improved force correlation and acceleration in the sampling of the phase space. We apply our method on SPC/E water, where we find a conservation of the average water structure. We then use our method to sample dialanine and the folding of TrpCage, where we find a good agreement with simulation data reported in the literature. Finally, we apply our methodologies on the initial stages of aggregation of a hexamer of Alzheimer's amyloid β fragment 25-35 (Aβ 25-35) and find that transitions within the hexameric aggregate are dominated by entropic barriers, while we speculate that especially the conformation entropy plays a major role in the formation of the fibril as a rate limiting factor.

  8. Analysis Of Economic Motivation When Individuals Choose An Educational Path

    Directory of Open Access Journals (Sweden)

    Viktor Anatolyevich Koksharov

    2015-03-01

    Full Text Available The authors consider the economic motivations when individuals choose an educational path. This line of research is relevant from both, the point of view of science — research of economic behavior of an individual, and the point of view of practice — allows to increase efficiency of investments in a human capital. The authors have developed the economic and mathematical model of choice of optimum educational paths by individuals. The model is realized in the software and approved on real data on more than 5,5 thousand students. For the analysis of the importance of rational economic expectations when an educational path has to be chosen, the paths chosen by students is compared and the educational paths optimum from the point of view of economic rationality are calculated. The analysis of the results has showed that mainly, the choice of educational paths happens according to the economic motivations. On the considered selection, 66 % of prospective students have chosen an optimum path from the point of view of economic preferences. The most significant factor providing development of optimum educational paths is an expectation of higher income upon completion of education — 22 % of all educational paths, and a possibility of cost-cutting of educating or state-subsidized education — 12 %. In our opinion, one of the most important practical results of the research of optimum educational path is the need to consider expectations of students and prospective student when developing a state policy of investment in human capital.

  9. A Path Analysis of Latino Parental, Teenager and Cultural Variables in Teenagers' Sexual Attitudes, Norms, Self-Efficacy, and Sexual Intentions1

    Science.gov (United States)

    Gaioso, Vanessa Pirani; Villarruel, Antonia Maria; Wilson, Lynda Anne; Azuero, Andres; Childs, Gwendolyn Denice; Davies, Susan Lane

    2015-01-01

    OBJECTIVE: to test a theoretical model based on the Parent-Based Expansion of the Theory of Planned Behavior examining relation between selected parental, teenager and cultural variables and Latino teenagers' intentions to engage in sexual behavior. METHOD: a cross-sectional correlational design based on a secondary data analysis of 130 Latino parent and teenager dyads. RESULTS: regression and path analysis procedures were used to test seven hypotheses and the results demonstrated partial support for the model. Parent familism and knowledge about sex were significantly associated with parents' attitudes toward sexual communication with their teenagers. Parent Latino acculturation was negatively associated with parents' self-efficacy toward sexual communication with their teenagers and positevely associated with parents' subjective norms toward sexual communication with their teenagers. Teenager knowledge about sex was significantly associated with higher levels of teenagers' attitudes and subjective norms about sexual communication with parents. Only the predictor of teenagers' attitudes toward having sex in the next 3 months was significantly associated with teenagers' intentions to have sex in the next 3 months. CONCLUSION: the results of this study provide important information to guide future research that can inform development of interventions to prevent risky teenager sexual behavior among Latinos. PMID:26312635

  10. Acquisition Path Analysis for a SFR Fuel Manufacturing Facility

    Energy Technology Data Exchange (ETDEWEB)

    Chang, H. L.; Kwon, E. H.; Ahn, S. K.; Ko, W. I.; Kim, H. D. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The coarse acquisition path analysis does not claim to be complete, but it identifies plausible acquisition paths detailed enough to show that the acquisition path analysis can provide reasonable insights regarding the safeguardability assessment, and demonstrates the availability of safeguards tools and measures, although not complete, required for the implementation of effective and efficient safeguards, including the coverage of the nuclear energy system (NES) by multiple intrinsic features and extrinsic measures. It also identifies strengths, weaknesses and gaps of a system in the area of proliferation resistance in a generally understandable form. The acquisition path analysis demonstrates that all acceptance limits for the safeguardability, in principle, are met although the acceptance limit for the efficiency of the IAEA safeguards can be answered only at the end of the Safeguards-by-Design process, including interaction with IAEA operations. However, procedures for destructive assay (DA) for the verification by the IAEA are not defined. Target values for non-destructive assay (NDA) for this type of nuclear material are also not defined. Therefore, there is a need to finish demonstrations of NDA measurements on novel material types and material flows. The acquisition path analysis also shows some concerns that need to be assured in the system design process: e. g., the ID number of all storage containers in all storage positions can be read or checked without moving the storage container, transfer of TRU fuel and heel/scrap (product stream) should be strictly separated from transfer routes for waste, to make the transfer of TRU fuel and heel/scrap into waste container impossible, etc.

  11. Solar array deployment analysis considering path-dependent behavior of a tape spring hinge

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Won; Park, Young Jin [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    Solar array deployment analysis is conducted considering the path-dependent nonlinear behavior of tape spring hinge. Such hinges offer many advantages over rigid hinges; they are self-deployable, self-locking, lightweight, and simple. However, they show strongly nonlinear behavior with respect to rotation angle, making deployment analysis difficult. To accurately consider the characteristics of tape spring hinges for deployment analysis, a path-dependent path identification (PI) method for tracing the previous path of the moment is introduced. To analyze the deployment motion, the governing equation for solar array deployment is derived within the framework of Kane's dynamic equation for three deployable solar panels. The numerical solution is compared with the Recurdyn's multi-body dynamics analysis solution using experimentally measured moment-rotation profiles. Solar array deployment analysis is conducted by considering and not considering the path-dependent PI method. This simulation example shows that the proposed path-dependent PI method is very effective for accurately predicting the deployment motion.

  12. Path integration and separation of variables in spaces of constant curvature in two and three dimensions

    International Nuclear Information System (INIS)

    Grosche, C.

    1993-10-01

    In this paper path integration in two- and three-dimensional spaces of constant curvature is discussed: i.e. the flat spaces R 2 and R 3 , the two- and three-dimensional sphere and the two- and three dimensional pseudosphere. The Laplace operator in these spaces admits separation of variables in various coordinate systems. In all these coordinate systems the path integral formulation will be stated, however in most of them an explicit solution in terms of the spectral expansion can be given only on a formal level. What can be stated in all cases, are the propagator and the corresponding Green function, respectively, depending on the invariant distance which is a coordinate independent quantity. This property gives rise to numerous identities connecting the corresponding path integral representations and propagators in various coordinate systems with each other. (orig.)

  13. Genetic variability, correlation and path analysis in sponge gourd ...

    African Journals Online (AJOL)

    Windows-7

    2013-02-06

    Feb 6, 2013 ... fiber used in industries for filter and cleaning the motor car, glass wares, kitchen ... The fibrous vascular system inside the fruit after been separated from the skin, ... was carried out to gather information on genetic variability ...

  14. Generalized causal mediation and path analysis: Extensions and practical considerations.

    Science.gov (United States)

    Albert, Jeffrey M; Cho, Jang Ik; Liu, Yiying; Nelson, Suchitra

    2018-01-01

    Causal mediation analysis seeks to decompose the effect of a treatment or exposure among multiple possible paths and provide casually interpretable path-specific effect estimates. Recent advances have extended causal mediation analysis to situations with a sequence of mediators or multiple contemporaneous mediators. However, available methods still have limitations, and computational and other challenges remain. The present paper provides an extended causal mediation and path analysis methodology. The new method, implemented in the new R package, gmediation (described in a companion paper), accommodates both a sequence (two stages) of mediators and multiple mediators at each stage, and allows for multiple types of outcomes following generalized linear models. The methodology can also handle unsaturated models and clustered data. Addressing other practical issues, we provide new guidelines for the choice of a decomposition, and for the choice of a reference group multiplier for the reduction of Monte Carlo error in mediation formula computations. The new method is applied to data from a cohort study to illuminate the contribution of alternative biological and behavioral paths in the effect of socioeconomic status on dental caries in adolescence.

  15. Modeling and analysis of laser active interference optical path

    Science.gov (United States)

    Shan, Cong-miao; Sun, Hua-yan; Zhao, Yan-zhong; Chen, Jian-biao; Ren, Jian-ying

    2017-10-01

    By using the geometrical optics and physical optics method, the models of wedge plate interference optical path, Michelson interferometer and Mach Zehnder interferometer thus three different active interference pattern are built. The optical path difference (OPD) launched by different interference patterns, fringe spacing and contrast expression have been derived. The results show that far field interference peak intensity of the wedge plate interference is small, so the detection distance is limited, Michelson interferometer with low contrast affects the performance of detection system, Mach Zehnder interferometer has greater advantages in peak intensity, the variable range of interference fringe spacing and contrast ratio. The results of this study are useful for the theoretical research and practical application of laser active interference detection.

  16. New Insights into Signed Path Coefficient Granger Causality Analysis.

    Science.gov (United States)

    Zhang, Jian; Li, Chong; Jiang, Tianzi

    2016-01-01

    Granger causality analysis, as a time series analysis technique derived from econometrics, has been applied in an ever-increasing number of publications in the field of neuroscience, including fMRI, EEG/MEG, and fNIRS. The present study mainly focuses on the validity of "signed path coefficient Granger causality," a Granger-causality-derived analysis method that has been adopted by many fMRI researches in the last few years. This method generally estimates the causality effect among the time series by an order-1 autoregression, and defines a positive or negative coefficient as an "excitatory" or "inhibitory" influence. In the current work we conducted a series of computations from resting-state fMRI data and simulation experiments to illustrate the signed path coefficient method was flawed and untenable, due to the fact that the autoregressive coefficients were not always consistent with the real causal relationships and this would inevitablely lead to erroneous conclusions. Overall our findings suggested that the applicability of this kind of causality analysis was rather limited, hence researchers should be more cautious in applying the signed path coefficient Granger causality to fMRI data to avoid misinterpretation.

  17. A touch-probe path generation method through similarity analysis between the feature vectors in new and old models

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Hye Sung; Lee, Jin Won; Yang, Jeong Sam [Dept. of Industrial Engineering, Ajou University, Suwon (Korea, Republic of)

    2016-10-15

    The On-machine measurement (OMM), which measures a work piece during or after the machining process in the machining center, has the advantage of measuring the work piece directly within the work space without moving it. However, the path generation procedure used to determine the measuring sequence and variables for the complex features of a target work piece has the limitation of requiring time-consuming tasks to generate the measuring points and mostly relies on the proficiency of the on-site engineer. In this study, we propose a touch-probe path generation method using similarity analysis between the feature vectors of three-dimensional (3-D) shapes for the OMM. For the similarity analysis between a new 3-D model and existing 3-D models, we extracted the feature vectors from models that can describe the characteristics of a geometric shape model; then, we applied those feature vectors to a geometric histogram that displays a probability distribution obtained by the similarity analysis algorithm. In addition, we developed a computer-aided inspection planning system that corrects non-applied measuring points that are caused by minute geometry differences between the two models and generates the final touch-probe path.

  18. Double path-integral migration velocity analysis: a real data example

    International Nuclear Information System (INIS)

    Costa, Jessé C; Schleicher, Jörg

    2011-01-01

    Path-integral imaging forms an image with no knowledge of the velocity model by summing over the migrated images obtained for a set of migration velocity models. Double path-integral imaging migration extracts the stationary velocities, i.e. those velocities at which common-image gathers align horizontally, as a byproduct. An application of the technique to a real data set demonstrates that quantitative information about the time migration velocity model can be determined by double path-integral migration velocity analysis. Migrated images using interpolations with different regularizations of the extracted velocities prove the high quality of the resulting time-migration velocity information. The so-obtained velocity model can then be used as a starting model for subsequent velocity analysis tools like migration tomography or other tomographic methods

  19. Statistical Analysis of the First Passage Path Ensemble of Jump Processes

    Science.gov (United States)

    von Kleist, Max; Schütte, Christof; Zhang, Wei

    2018-02-01

    The transition mechanism of jump processes between two different subsets in state space reveals important dynamical information of the processes and therefore has attracted considerable attention in the past years. In this paper, we study the first passage path ensemble of both discrete-time and continuous-time jump processes on a finite state space. The main approach is to divide each first passage path into nonreactive and reactive segments and to study them separately. The analysis can be applied to jump processes which are non-ergodic, as well as continuous-time jump processes where the waiting time distributions are non-exponential. In the particular case that the jump processes are both Markovian and ergodic, our analysis elucidates the relations between the study of the first passage paths and the study of the transition paths in transition path theory. We provide algorithms to numerically compute statistics of the first passage path ensemble. The computational complexity of these algorithms scales with the complexity of solving a linear system, for which efficient methods are available. Several examples demonstrate the wide applicability of the derived results across research areas.

  20. Path Transmissibility Analysis Considering Two Types of Correlations in Hydropower Stations

    Directory of Open Access Journals (Sweden)

    Baoping Zhi

    2013-01-01

    Full Text Available A new vibration model is built by introducing the head-cover vibration transfer path based on a previous analysis of the vertical vibration model for hydropower station units and powerhouses. This research focuses on disturbance- and parameter-related transfer paths in a practical situation. In a complex situation, the application of the stochastic perturbation method is expanded using an algebra synthesis method the Hadamard product, and theoretical analyses, and numerical simulations of transfer paths in the new vibration model are carried out through the expanded perturbation method. The path transfer force, the path transmissibility, and the path disturbance ranges in the frequency domain are provided. The results indicate that the methods proposed in this study can efficiently reduce the disturbance range and can accurately analyze the transfer paths of hydraulic-source vertical vibration in hydropower stations.

  1. Purely geometric path integral for spin-foams

    International Nuclear Information System (INIS)

    Shirazi, Atousa Chaharsough; Engle, Jonathan

    2014-01-01

    Spin-foams are a proposal for defining the dynamics of loop quantum gravity via path integral. In order for a path integral to be at least formally equivalent to the corresponding canonical quantization, at each point in the space of histories it is important that the integrand have not only the correct phase—a topic of recent focus in spin-foams—but also the correct modulus, usually referred to as the measure factor. The correct measure factor descends from the Liouville measure on the reduced phase space, and its calculation is a task of canonical analysis. The covariant formulation of gravity from which spin-foams are derived is the Plebanski–Holst formulation, in which the basic variables are a Lorentz connection and a Lorentz-algebra valued 2-form, called the Plebanski 2-form. However, in the final spin-foam sum, one usually sums over only spins and intertwiners, which label eigenstates of the Plebanski 2-form alone. The spin-foam sum is therefore a discretized version of a Plebanski–Holst path integral in which only the Plebanski 2-form appears, and in which the connection degrees of freedom have been integrated out. We call this a purely geometric Plebanski–Holst path integral. In prior work in which one of the authors was involved, the measure factor for the Plebanski–Holst path integral with both connection and 2-form variables was calculated. Before one discretizes this measure and incorporates it into a spin-foam sum, however, one must integrate out the connection in order to obtain the purely geometric version of the path integral. To calculate this purely geometric path integral is the principal task of the present paper, and it is done in two independent ways. Background independence of the resulting path integral is discussed in the final section, and gauge-fixing is discussed in appendix B. (paper)

  2. Roles of Impulsivity, Motivation, and Emotion Regulation in Procrastination - Path Analysis and Comparison Between Students and Non-students.

    Science.gov (United States)

    Wypych, Marek; Matuszewski, Jacek; Dragan, Wojciech Ł

    2018-01-01

    Procrastination - an irrational delay of intended actions despite expecting to be worse off - is a complex and non-homogenous phenomenon. Previous studies have found a number of correlates of procrastination, some of which seem to be particularly important. Impulsivity is closely connected to procrastination on behavioral, genetic, and neuronal levels. Difficulties in emotion regulation have also been shown to be strongly related to procrastination. Procrastination can also be considered as a motivation-based problem. To try to disentangle the connections of impulsivity, emotion regulation, and motivation to procrastination we collected data from over 600 subjects using multiple questionnaires (PPS - Pure Procrastination Scale; UPPSP - Impulsive Behavior Scale, ERQ - Emotion Regulation Questionnaire and MDT - Motivational Diagnostic Test). Structural equation modeling was performed to test several possible relationships between the measured variables. The effects of student status and age have also been investigated. The final path model was a directional model based on six explanatory variables and accounted for 70% of the variance in procrastination. Path analysis revealed that the strongest contributions to procrastination came from lack of value, delay discounting, and lack of perseverance, suggesting the involvement of motivation and impulsivity. The model also revealed the moderating role of expressive suppression between several aspects of impulsivity and procrastination. Close inspection of the paths' weights suggests that there may be two partly competing strategies for dealing with impulsivity and negative emotions: either to suppress emotions and impulsive reactions or to react impulsively, discarding previous plans, and to procrastinate. Path invariance analysis showed the significant moderating roles of student status and age. Both in non-students and high-age groups, the path leading from suppression to procrastination was insignificant. This suggests

  3. The study of system function analysis method for success path alarm design

    International Nuclear Information System (INIS)

    Kang, S. K.; Shin, Y. C.

    1999-01-01

    The key benefit to the common use of the critical function approach for safety and mission functions is that monitoring methods expected to be used by operaotrs during emergency condition are used continuously during normal operation. For each critical safety function there exists two or more success paths. Information Processing System monitors the availability, operation state and performance of the critical function success paths. In this paper, We have studied System Function Analysis(SFA) for the design of Success Path Alarm(SPA) for applying in KNGR. In here, we thought that SFA will help the design of SPA. The SFA can be applicable to the design of SPA according to NUREG-0711, also can induce the algorithm for alarm of system, train and flow path. We present a method of system function analysis for designing Success Path Alarm

  4. Cooperative Path Planning and Constraints Analysis for Master-Slave Industrial Robots

    Directory of Open Access Journals (Sweden)

    Yahui Gan

    2012-09-01

    Full Text Available A strategy of cooperative path planning for a master-slave multiple robot system is presented in this paper. The path planning method is based on motion constraints between the end-effectors of cooperative robots. Cooperation motions have been classified into three types by relative motions between end-effectors of master and slave robots, which is concurrent cooperation, coupled synchronous cooperation and combined synchronous cooperation. Based on this classification, position /orientation constraints and joint velocity constraints are explored in-depth here. In order to validate the path planning method and the theoretical developments in motion constraints analysis, representative experiments based on two industrial robots, Motoman VA1400 and HP20, are provided at the end of the paper. The experimental results have proved both the effectiveness of the path planning method and the correctness of the constraints analysis.

  5. Hamiltonian path integrals

    International Nuclear Information System (INIS)

    Prokhorov, L.V.

    1982-01-01

    The properties of path integrals associated with the allowance for nonstandard terms reflecting the operator nature of the canonical variables are considered. Rules for treating such terms (''equivalence rules'') are formulated. Problems with a boundary, the behavior of path integrals under canonical transformations, and the problem of quantization of dynamical systems with constraints are considered in the framework of the method

  6. Learner Variables in Second Language Listening Comprehension: An Exploratory Path Analysis

    Science.gov (United States)

    Vandergrift, Larry; Baker, Susan

    2015-01-01

    Listening comprehension plays a key role in language acquisition, yet little is known about the variables that contribute to the development of second language (L2) listening ability. This study sought to obtain empirical evidence for the impact of some of the learner variables and the degree to which they might predict success in L2 listening.…

  7. MinePath: Mining for Phenotype Differential Sub-paths in Molecular Pathways

    Science.gov (United States)

    Koumakis, Lefteris; Kartsaki, Evgenia; Chatzimina, Maria; Zervakis, Michalis; Vassou, Despoina; Marias, Kostas; Moustakis, Vassilis; Potamias, George

    2016-01-01

    Pathway analysis methodologies couple traditional gene expression analysis with knowledge encoded in established molecular pathway networks, offering a promising approach towards the biological interpretation of phenotype differentiating genes. Early pathway analysis methodologies, named as gene set analysis (GSA), view pathways just as plain lists of genes without taking into account either the underlying pathway network topology or the involved gene regulatory relations. These approaches, even if they achieve computational efficiency and simplicity, consider pathways that involve the same genes as equivalent in terms of their gene enrichment characteristics. Most recent pathway analysis approaches take into account the underlying gene regulatory relations by examining their consistency with gene expression profiles and computing a score for each profile. Even with this approach, assessing and scoring single-relations limits the ability to reveal key gene regulation mechanisms hidden in longer pathway sub-paths. We introduce MinePath, a pathway analysis methodology that addresses and overcomes the aforementioned problems. MinePath facilitates the decomposition of pathways into their constituent sub-paths. Decomposition leads to the transformation of single-relations to complex regulation sub-paths. Regulation sub-paths are then matched with gene expression sample profiles in order to evaluate their functional status and to assess phenotype differential power. Assessment of differential power supports the identification of the most discriminant profiles. In addition, MinePath assess the significance of the pathways as a whole, ranking them by their p-values. Comparison results with state-of-the-art pathway analysis systems are indicative for the soundness and reliability of the MinePath approach. In contrast with many pathway analysis tools, MinePath is a web-based system (www.minepath.org) offering dynamic and rich pathway visualization functionality, with the

  8. Self-controlled learning benefits: exploring contributions of self-efficacy and intrinsic motivation via path analysis.

    Science.gov (United States)

    Ste-Marie, Diane M; Carter, Michael J; Law, Barbi; Vertes, Kelly; Smith, Victoria

    2016-09-01

    Research has shown learning advantages for self-controlled practice contexts relative to yoked (i.e., experimenter-imposed) contexts; yet, explanations for this phenomenon remain relatively untested. We examined, via path analysis, whether self-efficacy and intrinsic motivation are important constructs for explaining self-controlled learning benefits. The path model was created using theory-based and empirically supported relationships to examine causal links between these psychological constructs and physical performance. We hypothesised that self-efficacy and intrinsic motivation would have greater predictive power for learning under self-controlled compared to yoked conditions. Participants learned double-mini trampoline progressions, and measures of physical performance, self-efficacy and intrinsic motivation were collected over two practice days and a delayed retention day. The self-controlled group (M = 2.04, SD = .98) completed significantly more skill progressions in retention than their yoked counterparts (M = 1.3, SD = .65). The path model displayed adequate fit, and similar significant path coefficients were found for both groups wherein each variable was predominantly predicted by its preceding time point (e.g., self-efficacy time 1 predicts self-efficacy time 2). Interestingly, the model was not moderated by group; thus, failing to support the hypothesis that self-efficacy and intrinsic motivation have greater predictive power for learning under self-controlled relative to yoked conditions.

  9. Correlação de pearson e análise de trilha identificando variáveis para caracterizar porta-enxerto de Pyrus communis L Pearson correlation and path analysis identifying variables for the characterization of Pyrus communis L. rootstock

    Directory of Open Access Journals (Sweden)

    Simone Padilha Galarça

    2010-08-01

    Full Text Available Objetivou-se, no presente trabalho, através de correlação de Pearson e análise de trilha, identificar variáveis para caracterizar porta-enxertos ananizantes para a cultura da pereira (Pyrus communis L.. Neste experimento foram utilizadas 49 plantas de pereira, plantadas nos canteiros do Departamento de Fitotecnia da FAEM/UFPel. As plantas foram avaliadas na época do seu crescimento vegetativo, segundo parâmetros descritos em instruções do Ministério da Agricultura, Pecuária e Abastecimento. Pela correlação de Pearson, as variáveis VP, NRP, HCP e FCNPRCL se destacaram. Na análise de trilha, a variável número de lenticelas obteve maior efeito positivo sobre VP, NRP e FCNPRCL, a variável ramificação do ramo demonstrou-se com efeito positivo sobre HCP, sendo essas duas variáveis consideradas eficazes no processo de seleção de porta-enxerto juntamente com as variáveis básicas.The objective of this work was to identify, through the Pearson correlation and path analysis, variables to characterize rootstocks suitable for the cultivation of the pear (Pyrus communis L.. In this experiment 49 pear specimens were used, planted in flowerbeds at the Phytotechny Department. The plants were evaluated at the time of growth, according to parameters described in the instructions of the Ministério da Agricultura, Pecuária e Abastecimento. According to the Pearson correlation, the variables VP, NRP, ETA and FCNPRCL stood out. In path analysis, the variable number of lenticels had a more positive effect on VP, NRP and FCNPRCL, variable branch of the industry had a more positive effect on ETA. Both variables were considered effective in the process of selection of rootstock together with the basic variables.

  10. Determinants of participation restriction among community dwelling stroke survivors: A path analysis

    Directory of Open Access Journals (Sweden)

    Chang Anne M

    2009-09-01

    Full Text Available Abstract Background Apart from promoting physical recovery and assisting in activities of daily living, a major challenge in stroke rehabilitation is to minimize psychosocial morbidity and to promote the reintegration of stroke survivors into their family and community. The identification of key factors influencing long-term outcome are essential in developing more effective rehabilitation measures for reducing stroke-related morbidity. The aim of this study was to test a theoretical model of predictors of participation restriction which included the direct and indirect effects between psychosocial outcomes, physical outcome, and socio-demographic variables at 12 months after stroke. Methods Data were collected from 188 stroke survivors at 12 months following their discharge from one of the two rehabilitation hospitals in Hong Kong. The settings included patients' homes and residential care facilities. Path analysis was used to test a hypothesized model of participation restriction at 12 months. Results The path coefficients show functional ability having the largest direct effect on participation restriction (β = 0.51. The results also show that more depressive symptoms (β = -0.27, low state self-esteem (β = 0.20, female gender (β = 0.13, older age (β = -0.11 and living in a residential care facility (β = -0.12 have a direct effect on participation restriction. The explanatory variables accounted for 71% of the variance in explaining participation restriction at 12 months. Conclusion Identification of stroke survivors at risk of high levels of participation restriction, depressive symptoms and low self-esteem will assist health professionals to devise appropriate rehabilitation interventions that target improving both physical and psychosocial functioning.

  11. An operator expansion technique for path integral analysis

    International Nuclear Information System (INIS)

    Tsvetkov, I.V.

    1995-01-01

    A new method of path integral analysis in the framework of a power series technique is presented. The method is based on the operator expansion of an exponential. A regular procedure to calculate the correction terms is found. (orig.)

  12. Repeatability, correlation and path analysis of physical and chemical characteristics of peach fruits

    Directory of Open Access Journals (Sweden)

    Rosana Gonçalves Pires Matias

    2014-12-01

    Full Text Available This study aimed to determine the number of measurements necessary to evaluate physical and chemical characteristics of peach fruits, study the relationships between them and their direct and indirect effects on the content of ascorbic acid and total carotenoids. The characteristics skin and pulp color, fruit weight, suture, equatorial and polar diameters, firmness, soluble solids (SS, titratable acidity (TA, SS/TA ratio, ascorbic acid and total carotenoids were evaluated in 39 cultivars of peach and 3 cultivars of nectarine from the orchard of the Universidade Federal de Viçosa. The repeatability coefficient was estimated by ANOVA and CPCOR. Phenotypic correlation coefficients (rf were estimated and, after the multicollinearity diagnostics, they were unfolded to direct and indirect effects of the explanatory variables on the response variable using path analysis. There was agreement on the magnitude of repeatability coefficients obtained by the two methods; however, they varied among the 14 characteristics. The highest correlations were found between FW, SD, ED and PD. Seven fruits are sufficient to evaluate the physical and chemical characteristics of peach with a correlation coefficient of 90%. The characteristics considered in the path diagrams (b* skin, hº skin, b* pulp, hº pulp, ED, PD, FIR, SS, SS/AT and TC are not the main determinants of the ascorbic acid. The yellow hue of the pulp (hº pulp has the potential to be used in indirect selection for total carotenoids.

  13. An analysis of 3D particle path integration algorithms

    International Nuclear Information System (INIS)

    Darmofal, D.L.; Haimes, R.

    1996-01-01

    Several techniques for the numerical integration of particle paths in steady and unsteady vector (velocity) fields are analyzed. Most of the analysis applies to unsteady vector fields, however, some results apply to steady vector field integration. Multistep, multistage, and some hybrid schemes are considered. It is shown that due to initialization errors, many unsteady particle path integration schemes are limited to third-order accuracy in time. Multistage schemes require at least three times more internal data storage than multistep schemes of equal order. However, for timesteps within the stability bounds, multistage schemes are generally more accurate. A linearized analysis shows that the stability of these integration algorithms are determined by the eigenvalues of the local velocity tensor. Thus, the accuracy and stability of the methods are interpreted with concepts typically used in critical point theory. This paper shows how integration schemes can lead to erroneous classification of critical points when the timestep is finite and fixed. For steady velocity fields, we demonstrate that timesteps outside of the relative stability region can lead to similar integration errors. From this analysis, guidelines for accurate timestep sizing are suggested for both steady and unsteady flows. In particular, using simulation data for the unsteady flow around a tapered cylinder, we show that accurate particle path integration requires timesteps which are at most on the order of the physical timescale of the flow

  14. Intimate partner violence, common mental disorders and household food insecurity: an analysis using path analysis.

    Science.gov (United States)

    Moraes, Claudia Leite de; Marques, Emanuele Souza; Reichenheim, Michael Eduardo; Ferreira, Marcela de Freitas; Salles-Costa, Rosana

    2016-11-01

    To investigate the direct and indirect associations between psychological and physical intimate partner violence and the occurrence of common mental disorders (CMD) and how they relate to the occurrence of household food insecurity (HFI). This was a population-based cross-sectional study. Intimate partner violence was assessed using the Brazilian version of the Revised Conflict Tactics Scale (CTS2) and HFI was assessed using the Brazilian Food Insecurity Scale. The propositional analytical model was based on a review of the literature and was tested using path analysis. Duque de Caxias, Greater Rio de Janeiro, Brazil (April-December 2010). Women (n 849) who had been in a relationship in the 12 months preceding the interview. Both psychological and physical violence were found to be major risk factors of HFI. Psychological violence was associated with HFI indirectly via physical violence and CMD, and directly by an unidentified path. The effects of physical violence seemed to be manifested exclusively through CMD. Most of the variables in the propositional model related to socio-economic position, demographic characteristics, degree of women's social support and partner alcohol misuse were retained in the 'final' model, indicating that these factors contribute significantly to the increased likelihood of HFI. The results reinforce the importance of considering domestic violence and other psychosocial aspects of family life when implementing interventions designed to reduce/eradicate HFI.

  15. Path analysis of the productive traits in Sorghum species

    Directory of Open Access Journals (Sweden)

    Ikanović Jela

    2011-01-01

    Full Text Available This research studied the phenotypic correlation coefficients between three Sorghum species, namely forage sorghum S. bicolor Moench. (c. NS-Džin, Sudan grass S. sudanense L. (c. Zora and interspecies hybrid S. bicolor x S. sudanense (c. Siloking. The analyses were performed on plant material samples taken from the first cutting, when plants were in the beginning phase of tasseling. The following morphologic traits were studied: plant height, number of leaves per plant, stem leaf weight and mean stem weight. Additionally, their direct and indirect effect on dependent variable green biomass yield was analyzed, for which path coefficients were calculated. This method enables more quality and full insight into relations existing among the studied traits, more precise establishment of cause-effect connections among them, as well as to separate direct from indirect effects of any particular trait on dependent variable, being biomass yield in this case. The analysis of phenotypic coefficients revealed differences in direct and indirect effect of certain traits on dependent variable. Sudan grass had the highest stem (2.281 m and most leaves per plant (7.917. Forage sorghum had the largest leaf weight per plant (49.05 g, while interspecies hybrid had the highest mean stem weight (80.798 g. Variations of these morphologic traits among species were found to be significant and very significant. Morphologic traits - stem height and weight significantly affected sorghum green biomass yield. Leaf number and leaf portion in total biomass were negatively correlated with yield. Cultivars differed significantly regarding morphologic and productive traits. Sudan grass had the lowest green biomass yield, while forage sorghum and interspecies hybrid had significant yield increase.

  16. Opening Remarks of the Acquisition Path Analysis Methodology Session

    International Nuclear Information System (INIS)

    Renis, T.

    2015-01-01

    An overview of the recent development work that has been done on acquisition path analysis, implementation of the methodologies within the Department of Safeguards, lessons learned and future areas for development will be provided. (author)

  17. Diversion path analysis handbook. Volume 2 (of 4 volumes). Example

    International Nuclear Information System (INIS)

    Goodwin, K.E.; Schleter, J.C.; Maltese, M.D.K.

    1978-11-01

    Volume 2 of the Handbook is divided into two parts, the workpaper documentation and the summary documentation. The former sets forth, in terms of the hypothetical process, the analysis guidelines, the information gathered, the characterization of the process, the specific diversion paths related to the process, and, finally, the results and findings of the Diversion Path Analysis (DPA). The summary documentation, made up of portions of sections already prepared for the workpapers, is a concise statement of results and recommendations for management use. Most of the details available in the workpapers are not used, or are held to a minimum, in this report. Also, some rearrangement of the excerpted sections has been made in order to permit rapid comprehension by a manager having only limited time to devote to study and review of the analysis

  18. A Path Analysis of the Effects of Mental Health and Socio-personal Factors on Breastfeeding Problems in Infants Aged Less than Six Months

    Directory of Open Access Journals (Sweden)

    Zohreh Mahmoodi

    2018-01-01

    Full Text Available Background: Despite the large number of studies conducted on breastfeeding, no studies have yet examined the direct and indirect effects of socio-personal factors and mental health on breastfeeding. Aim: This study aimed to analyze of the effects of mental health and socio-personal factors on breastfeeding in infants aged less than six months. Method: This analytical cross-sectional study was conducted on 465 eligible mothers visiting general health centers in a northern city of Iran, in 2015. Data were collected using the researcher-made scale of socio-personal factors of breastfeeding, Spielberger’s State-Trait Anxiety Inventory, Beck’s Depression Inventory, Cohen’s Perceived Stress Scale, the Breastfeeding Difficulties Questionnaire, the Access to Healthcare Questionnaire, and the Poor Health Behaviors Questionnaire. Results: The path analysis of the mental health variables showed that breastfeeding problems are associated through a direct path with depression, through an indirect path with stress, and through both paths with anxiety; a positive correlation was thus observed between these variables and breastfeeding problems. Poor health behaviors also contributed to mothers’ breastfeeding problems through a direct path and indirectly by affecting their level of depression. Income had the highest positive effect (B=0.66, while the number of children had the highest negative effect (B=-3.16 on breastfeeding problems through a direct path. Poor health behaviors had the highest positive effect (B=0.75 and family support had the highest negative effect (B=-0.11 on breastfeeding. Implications for Practice: The early diagnosis of poor postpartum mental health in mothers can help reduce breastfeeding problems.

  19. Multi-Dimensional Path Queries

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    1998-01-01

    to create nested path structures. We present an SQL-like query language that is based on path expressions and we show how to use it to express multi-dimensional path queries that are suited for advanced data analysis in decision support environments like data warehousing environments......We present the path-relationship model that supports multi-dimensional data modeling and querying. A path-relationship database is composed of sets of paths and sets of relationships. A path is a sequence of related elements (atoms, paths, and sets of paths). A relationship is a binary path...

  20. Multiscale Path Metrics for the Analysis of Discrete Geometric Structures

    Science.gov (United States)

    2017-11-30

    Report: Multiscale Path Metrics for the Analysis of Discrete Geometric Structures The views, opinions and/or findings contained in this report are those...Analysis of Discrete Geometric Structures Report Term: 0-Other Email: tomasi@cs.duke.edu Distribution Statement: 1-Approved for public release

  1. The Path Analysis of Farmers' Income Structure in Yunnan Province

    OpenAIRE

    XIAO, Yongtian; CUI, Yu; HU, Lijia

    2015-01-01

    The problem of farmers' income growth is the key of issues concerning agriculture, countryside and farmers, so the farmers’ income growth is the fundamental starting point for agricultural and rural economic development. In this paper, we use the statistics concerning farmers' income in Yunnan Province from 1995 to 2012, to perform the path analysis of components of farmers' income in Yunnan Province, study the path of influence of components of farmers' income on farmers' net income, and t...

  2. Comparison of Estimation Techniques for Vibro-Acoustic Transfer Path Analysis

    Directory of Open Access Journals (Sweden)

    Paulo Eduardo França Padilha

    2006-01-01

    Full Text Available Vibro-acoustic Transfer Path Analysis (TPA is a tool to evaluate the contribution of different energy propagation paths between a source and a receiver, linked to each other by a number of connections. TPA is typically used to quantify and rank the relative importance of these paths in a given frequency band, determining the most significant one to the receiver. Basically, two quantities have to be determined for TPA: the operational forces at each transfer path and the Frequency Response Functions (FRF of these paths. The FRF are obtained either experimentally or analytically, and the influence of the mechanical impedance of the source can be taken into account or not. The operational forces can be directly obtained from measurements using force transducers or indirectly estimated from auxiliary response measurements. Two methods to obtain the operational forces indirectly – the Complex Stiffness Method (CSM and the Matrix Inversion Method (MIM – associated with two possible configurations to determine the FRF – including and excluding the source impedance – are presented and discussed in this paper. The effect of weak and strong coupling among the paths is also commented considering the techniques previously presented. The main conclusion is that, with the source removed, CSM gives more accurate results. On the other hand, with the source present, MIM is preferable. In the latter case, CSM should be used only if there is a high impedance mismatch between the source and the receiver. Both methods are not affected by a higher or lower degree of coupling among the transfer paths.

  3. PATH COEFFICIENT ANALYSIS G39×CIHERANG AND MENTIK WANGI×G39 RICE IN F4 GENERATION

    Directory of Open Access Journals (Sweden)

    Totok Agung D.H.

    2014-02-01

    Full Text Available Current research was conducted with the objectives to identify the utmost traits that may be beneficial for the higher productivity of the grains on high protein content genotypes lines by path coefficient. Path coefficient can define coefficient correlation directly and indirectly to gain information about nature relationship between yield component and protein content to grain yield. Research material consisted of 61 selected plants from G39×Ciherang and 66 selected plants from Mentik Wangi×G39 at F4 generation. Plants were planted in Banyumas in May 2011. Number of panicles per plant, panicle length, 1000 g of grain weight, percentage of filled grain per panicle, protein content, and grain yield were correlated by using Pearson correlation and were followed by path coefficient. Number of panicles per plant, panicle length, 1000 g of grain weight, percentage filled grain per panicle, and protein content were used as dependent variable, while grain yield was used as independent variable. The result showed that protein content in both populations was not correlated with all yield components. The numbers of panicles, followed by panicle length, had highest positive direct effect to yield. The number of panicle was a positive mediator variable to yield from another variable.

  4. Analysis of the variability of occlusal function patterns in masticatory movement--use of the GEMAS software.

    Science.gov (United States)

    Kordass, B

    2006-04-01

    Individual masticatory patterns are similar to chaotic tangles of tortuous paths and are characterized by variability. The analysis of such masticatory patterns is therefore difficult. The new GEMAS software--Greifswald Movement Analyzing System--with which the variability of the masticatory function can be examined, is presented. Intersecting planes are placed through the orbit of the chewing cycles with which it is possible to wonder from the intercuspal position up to the maximum mouth-opening position of the masticatory pattern. The opening and closing points are displayed in different colors. Zones where masticatory paths converge or diverge can be determined, including the fan or funnel-shaped entering and exiting movements close to the centric position and the extent of their spread. A special diagram visualizes the rhythmic sequence of entering and subsequent exiting movement. The relation between restricted variability or monotony and forms of disease of the masticatory system is indicated by reference to case examples. The more monotonous or stereotyped the chewing cycles are, the higher is the risk of permanent wear of anatomical structures. Attention should therefore also be paid to variability in the individual occlusal surface design of dental restorations.

  5. Path Expressions

    Science.gov (United States)

    1975-06-01

    Traditionally, synchronization of concurrent processes is coded in line by operations on semaphores or similar objects. Path expressions move the...discussion about a variety of synchronization primitives . An analysis of their relative power is found in [3]. Path expressions do not introduce yet...another synchronization primitive . A path expression relates to such primitives as a for- or while-statement of an ALGOL-like language relates to a JUMP

  6. Quantifying tight-gas sandstone permeability via critical path analysis

    Science.gov (United States)

    Rock permeability has been actively investigated over the past several decades by the geosciences community. However, its accurate estimation still presents significant technical challenges, especially in spatially complex rocks. In this letter, we apply critical path analysis (CPA) to estimate perm...

  7. A Comparison of Approaches for the Analysis of Interaction Effects between Latent Variables Using Partial Least Squares Path Modeling

    Science.gov (United States)

    Henseler, Jorg; Chin, Wynne W.

    2010-01-01

    In social and business sciences, the importance of the analysis of interaction effects between manifest as well as latent variables steadily increases. Researchers using partial least squares (PLS) to analyze interaction effects between latent variables need an overview of the available approaches as well as their suitability. This article…

  8. Genetic parameters and path analysis in cowpea genotypes grown in the Cerrado/Pantanal ecotone.

    Science.gov (United States)

    Lopes, K V; Teodoro, P E; Silva, F A; Silva, M T; Fernandes, R L; Rodrigues, T C; Faria, T C; Corrêa, A M

    2017-05-18

    Estimating genetic parameters in plant breeding allows us to know the population potential for selecting and designing strategies that can maximize the achievement of superior genotypes. The objective of this study was to evaluate the genetic potential of a population of 20 cowpea genotypes by estimating genetic parameters and path analysis among the traits to guide the selection strategies. The trial was conducted in randomized block design with four replications. Its morphophysiological components, components of green grain production and dry grain yield were estimated from genetic use and correlations between the traits. Phenotypic correlations were deployed through path analysis into direct and indirect effects of morphophysiological traits and yield components on dry grain yield. There were significant differences (P < 0.01) between the genotypes for most the traits, indicating the presence of genetic variability in the population and the possibility of practicing selection. The population presents the potential for future genetic breeding studies and is highly promising for the selection of traits dry grain yield, the number of grains per pod, and hundred grains mass. A number of grains per green pod is the main determinant trait of dry grain yield that is also influenced by the cultivar cycle and that the selection for the dry grain yield can be made indirectly by selecting the green pod mass and green pod length.

  9. Diversion path analysis for the Swedish geological repository

    International Nuclear Information System (INIS)

    Fritzell, Anni; Meer, Klaas Van Der

    2008-02-01

    The Swedish strategy to handle the spent fuel from the nuclear power plants is direct disposal in a geological repository. The safeguards regime covering all nuclear material in the state will be expanded to cover the new repository, which will require a novel safeguards approach due mainly to the inaccessibility of the fuel after disposal. The safeguards approach must be able to provide a high level of assurance that the fuel in the repository not diverted, but must also be resource efficient. An attractive approach with regards to use of resources is to monitor only the access points to the repository, i.e. the openings. The implementation of such an approach can only be allowed if it is shown to be sufficiently secure. With the purpose of determining the applicability of this 'black box' approach, a diversion path analysis for the Swedish geological repository has been carried out. The result from the analysis shows that all credible diversion paths could be covered by the black-box safeguards approach provided that the identified boundary conditions can be met

  10. Diversion path analysis for the Swedish geological repository

    Energy Technology Data Exchange (ETDEWEB)

    Fritzell, Anni (Dept. of Physics and Astronomy, Uppsala Univ., Uppsala (Sweden)); Meer, Klaas Van Der (Belgian Nuclear Research Center SCK.CEN (BG))

    2008-02-15

    The Swedish strategy to handle the spent fuel from the nuclear power plants is direct disposal in a geological repository. The safeguards regime covering all nuclear material in the state will be expanded to cover the new repository, which will require a novel safeguards approach due mainly to the inaccessibility of the fuel after disposal. The safeguards approach must be able to provide a high level of assurance that the fuel in the repository not diverted, but must also be resource efficient. An attractive approach with regards to use of resources is to monitor only the access points to the repository, i.e. the openings. The implementation of such an approach can only be allowed if it is shown to be sufficiently secure. With the purpose of determining the applicability of this 'black box' approach, a diversion path analysis for the Swedish geological repository has been carried out. The result from the analysis shows that all credible diversion paths could be covered by the black-box safeguards approach provided that the identified boundary conditions can be met

  11. Photon propagation in heterogeneous optical media with spatial correlations: enhanced mean-free-paths and wider-than-exponential free-path distributions

    International Nuclear Information System (INIS)

    Davis, A.B.; Marshak, Alexander

    2004-01-01

    Beer's law of exponential decay in direct transmission is well-known but its break-down in spatially variable optical media has been discussed only sporadically in the literature. We document here this break-down in three-dimensional (3D) media with complete generality and explore its ramifications for photon propagation. We show that effective transmission laws and their associated free-path distributions (FPDs) are in fact never exactly exponential in variable media of any kind. Moreover, if spatial correlations in the extinction field extend at least to the scale of the mean-free-path (MFP), FPDs are necessarily wider-than-exponential in the sense that all higher-order moments of the relevant mean-field FPDs exceed those of the exponential FPD, even if it is tuned to yield the proper MFP. The MFP itself is always larger than the inverse of average extinction in a variable medium. In a vast and important class of spatially-correlated random media, the MFP is indeed the average of the inverse of extinction. We translate these theoretical findings into a practical method for deciding a priori when 3D effects become important. Finally, we discuss an obvious but limited analogy between our analysis of spatial variability and the well-known effects of strong spectral variability in gaseous media when observed or modeled at moderate resolution

  12. Hard paths, soft paths or no paths? Cross-cultural perceptions of water solutions

    Science.gov (United States)

    Wutich, A.; White, A. C.; White, D. D.; Larson, K. L.; Brewis, A.; Roberts, C.

    2014-01-01

    In this study, we examine how development status and water scarcity shape people's perceptions of "hard path" and "soft path" water solutions. Based on ethnographic research conducted in four semi-rural/peri-urban sites (in Bolivia, Fiji, New Zealand, and the US), we use content analysis to conduct statistical and thematic comparisons of interview data. Our results indicate clear differences associated with development status and, to a lesser extent, water scarcity. People in the two less developed sites were more likely to suggest hard path solutions, less likely to suggest soft path solutions, and more likely to see no path to solutions than people in the more developed sites. Thematically, people in the two less developed sites envisioned solutions that involve small-scale water infrastructure and decentralized, community-based solutions, while people in the more developed sites envisioned solutions that involve large-scale infrastructure and centralized, regulatory water solutions. People in the two water-scarce sites were less likely to suggest soft path solutions and more likely to see no path to solutions (but no more likely to suggest hard path solutions) than people in the water-rich sites. Thematically, people in the two water-rich sites seemed to perceive a wider array of unrealized potential soft path solutions than those in the water-scarce sites. On balance, our findings are encouraging in that they indicate that people are receptive to soft path solutions in a range of sites, even those with limited financial or water resources. Our research points to the need for more studies that investigate the social feasibility of soft path water solutions, particularly in sites with significant financial and natural resource constraints.

  13. Path analysis of phenotypic traits in young cacao plants under drought conditions.

    Science.gov (United States)

    Santos, Emerson Alves Dos; Almeida, Alex-Alan Furtado de; Branco, Marcia Christina da Silva; Santos, Ivanildes Conceição Dos; Ahnert, Dario; Baligar, Virupax C; Valle, Raúl René

    2018-01-01

    Drought is worldwide considered one of the most limiting factors of Theobroma cacao production, which can be intensified by global climate changes. In this study, we aimed to investigate the phenotypic correlation among morphological characteristics of cacao progenies submitted to irrigation and drought conditions and their partitions into direct and indirect effects. Path analysis with phenotypic plasticity index was used as criteria for estimation of basic and explanatory variables. The experiment was conducted in a greenhouse at the Cacao Research Center (CEPEC), Ilhéus, Bahia, Brazil, in a randomized block 21 x 2 factorial arrangement [21 cacao progenies obtained from complete diallel crosses and two water regimes (control and drought)] and six replications. In general, drought conditions influenced biomass production in most progenies, causing significant reductions in total leaf area, leaf number, leaf biomass, fine-roots length (diameter cacao progenies drought tolerant.

  14. PathNet: a tool for pathway analysis using topological information

    Directory of Open Access Journals (Sweden)

    Dutta Bhaskar

    2012-09-01

    Full Text Available Abstract Background Identification of canonical pathways through enrichment of differentially expressed genes in a given pathway is a widely used method for interpreting gene lists generated from high-throughput experimental studies. However, most algorithms treat pathways as sets of genes, disregarding any inter- and intra-pathway connectivity information, and do not provide insights beyond identifying lists of pathways. Results We developed an algorithm (PathNet that utilizes the connectivity information in canonical pathway descriptions to help identify study-relevant pathways and characterize non-obvious dependencies and connections among pathways using gene expression data. PathNet considers both the differential expression of genes and their pathway neighbors to strengthen the evidence that a pathway is implicated in the biological conditions characterizing the experiment. As an adjunct to this analysis, PathNet uses the connectivity of the differentially expressed genes among all pathways to score pathway contextual associations and statistically identify biological relations among pathways. In this study, we used PathNet to identify biologically relevant results in two Alzheimer’s disease microarray datasets, and compared its performance with existing methods. Importantly, PathNet identified de-regulation of the ubiquitin-mediated proteolysis pathway as an important component in Alzheimer’s disease progression, despite the absence of this pathway in the standard enrichment analyses. Conclusions PathNet is a novel method for identifying enrichment and association between canonical pathways in the context of gene expression data. It takes into account topological information present in pathways to reveal biological information. PathNet is available as an R workspace image from http://www.bhsai.org/downloads/pathnet/.

  15. Variable system: An alternative approach for the analysis of mediated moderation.

    Science.gov (United States)

    Kwan, Joyce Lok Yin; Chan, Wai

    2018-06-01

    Mediated moderation (meMO) occurs when the moderation effect of the moderator (W) on the relationship between the independent variable (X) and the dependent variable (Y) is transmitted through a mediator (M). To examine this process empirically, 2 different model specifications (Type I meMO and Type II meMO) have been proposed in the literature. However, both specifications are found to be problematic, either conceptually or statistically. For example, it can be shown that each type of meMO model is statistically equivalent to a particular form of moderated mediation (moME), another process that examines the condition when the indirect effect from X to Y through M varies as a function of W. Consequently, it is difficult for one to differentiate these 2 processes mathematically. This study therefore has 2 objectives. First, we attempt to differentiate moME and meMO by proposing an alternative specification for meMO. Conceptually, this alternative specification is intuitively meaningful and interpretable, and, statistically, it offers meMO a unique representation that is no longer identical to its moME counterpart. Second, using structural equation modeling, we propose an integrated approach for the analysis of meMO as well as for other general types of conditional path models. VS, a computer software program that implements the proposed approach, has been developed to facilitate the analysis of conditional path models for applied researchers. Real examples are considered to illustrate how the proposed approach works in practice and to compare its performance against the traditional methods. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  16. A path flux analysis method for the reduction of detailed chemical kinetic mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Wenting; Ju, Yiguang [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States); Chen, Zheng [State Key Laboratory for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing 100871 (China); Gou, Xiaolong [School of Power Engineering, Chongqing University, Chongqing 400044 (China)

    2010-07-15

    A direct path flux analysis (PFA) method for kinetic mechanism reduction is proposed and validated by using high temperature ignition, perfect stirred reactors, and steady and unsteady flame propagations of n-heptane and n-decane/air mixtures. The formation and consumption fluxes of each species at multiple reaction path generations are analyzed and used to identify the important reaction pathways and the associated species. The formation and consumption path fluxes used in this method retain flux conservation information and are used to define the path indexes for the first and the second generation reaction paths related to a targeted species. Based on the indexes of each reaction path for the first and second generations, different sized reduced chemical mechanisms which contain different number of species are generated. The reduced mechanisms of n-heptane and n-decane obtained by using the present method are compared to those generated by the direct relation graph (DRG) method. The reaction path analysis for n-decane is conducted to demonstrate the validity of the present method. The comparisons of the ignition delay times, flame propagation speeds, flame structures, and unsteady spherical flame propagation processes showed that with either the same or significantly less number of species, the reduced mechanisms generated by the present PFA are more accurate than that of DRG in a broad range of initial pressures and temperatures. The method is also integrated with the dynamic multi-timescale method and a further increase of computation efficiency is achieved. (author)

  17. INTRINSIC FACTORS AND FIRM FINANCIAL ANALYSIS WITH TRIPPLE BOTTOM LINES AS INTERVENING VARIABLE AGAINST FIRM VALUE Empirical Studies on Property and Real Estate Companies Year 2010-2013

    Directory of Open Access Journals (Sweden)

    Mia Andika Sari

    2016-09-01

    Full Text Available This research conducted to examine the influence of intrinsic factors which being peroxided with Capital Structure, Firm Size, Firm Age and Financial factors that being peroxided with liquidity, profitability also with another activities using triple bottom lines as Intervening Variable against Firm Value of Property Industries. The data that being used in this study were obtained from published financial statements during the period 2010 to 2013, as well as annual reports that can be accessed through the IDX website. Data analysis technique used in this study is a regression with panel data and path analysis. The results of this research showed that intrinsic factors and financial variables have a significant influence on the firm value, as well as intrinsic factors and financial variables have a significant influence on the triple bottom lines. From the results of path analysis demonstrated that the indirect effect using the triple bottom lines as a intervening variable was greater than the direct effect.

  18. Time optimal paths for high speed maneuvering

    Energy Technology Data Exchange (ETDEWEB)

    Reister, D.B.; Lenhart, S.M.

    1993-01-01

    Recent theoretical results have completely solved the problem of determining the minimum length path for a vehicle with a minimum turning radius moving from an initial configuration to a final configuration. Time optimal paths for a constant speed vehicle are a subset of the minimum length paths. This paper uses the Pontryagin maximum principle to find time optimal paths for a constant speed vehicle. The time optimal paths consist of sequences of axes of circles and straight lines. The maximum principle introduces concepts (dual variables, bang-bang solutions, singular solutions, and transversality conditions) that provide important insight into the nature of the time optimal paths. We explore the properties of the optimal paths and present some experimental results for a mobile robot following an optimal path.

  19. ComPath: comparative enzyme analysis and annotation in pathway/subsystem contexts

    Directory of Open Access Journals (Sweden)

    Kim Sun

    2008-03-01

    Full Text Available Abstract Background Once a new genome is sequenced, one of the important questions is to determine the presence and absence of biological pathways. Analysis of biological pathways in a genome is a complicated task since a number of biological entities are involved in pathways and biological pathways in different organisms are not identical. Computational pathway identification and analysis thus involves a number of computational tools and databases and typically done in comparison with pathways in other organisms. This computational requirement is much beyond the capability of biologists, so information systems for reconstructing, annotating, and analyzing biological pathways are much needed. We introduce a new comparative pathway analysis workbench, ComPath, which integrates various resources and computational tools using an interactive spreadsheet-style web interface for reliable pathway analyses. Results ComPath allows users to compare biological pathways in multiple genomes using a spreadsheet style web interface where various sequence-based analysis can be performed either to compare enzymes (e.g. sequence clustering and pathways (e.g. pathway hole identification, to search a genome for de novo prediction of enzymes, or to annotate a genome in comparison with reference genomes of choice. To fill in pathway holes or make de novo enzyme predictions, multiple computational methods such as FASTA, Whole-HMM, CSR-HMM (a method of our own introduced in this paper, and PDB-domain search are integrated in ComPath. Our experiments show that FASTA and CSR-HMM search methods generally outperform Whole-HMM and PDB-domain search methods in terms of sensitivity, but FASTA search performs poorly in terms of specificity, detecting more false positive as E-value cutoff increases. Overall, CSR-HMM search method performs best in terms of both sensitivity and specificity. Gene neighborhood and pathway neighborhood (global network visualization tools can be used

  20. Moderated path analysis of the relationships between masculinity and men's attitudes toward seeking psychological help.

    Science.gov (United States)

    Levant, Ronald F; Stefanov, Dimitre G; Rankin, Thomas J; Halter, Margaret J; Mellinger, Chris; Williams, Christine M

    2013-07-01

    This study tested a theoretical model of one mediator and 4 moderators of the relationships between 2 masculinity variables (Traditional Masculinity Ideology and Gender Role Conflict) and Attitudes Toward Seeking Professional Psychological Services (Attitudes). Self-stigma was the hypothesized mediator, and the hypothesized moderators were (a) Depression, (b) General Self-efficacy, (c) Precontemplation, and (d) Barriers to Help-seeking. A sample of 654 men responded to an online survey of 9 questionnaires. After evaluating mediation in the absence of moderation, moderated path analyses were conducted for each moderator. The relationship between Traditional Masculinity Ideology and Attitudes was partially mediated by Self-stigma, whereas that between Gender Role Conflict and Attitudes was completely mediated. No indirect or direct paths involving Gender Role Conflict were moderated by any moderators. Both Depression and Barriers to Help-seeking demonstrated mediated moderation by moderating both Stage 1 (the path from Traditional Masculinity Ideology to Self-stigma) of the mediated relationships and the direct effects between Traditional Masculinity Ideology and Attitudes. Precontemplation moderated the direct effect between Traditional Masculinity Ideology and Attitudes. The findings suggest that the relationships between masculinity variables and men's negative help-seeking attitudes may be better understood through their relationships with other variables that serve as mediators and moderators. Findings from the present study may offer some direction in the design of interventions to remediate men's negative help-seeking attitudes. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  1. Path-Wise Test Data Generation Based on Heuristic Look-Ahead Methods

    Directory of Open Access Journals (Sweden)

    Ying Xing

    2014-01-01

    Full Text Available Path-wise test data generation is generally considered an important problem in the automation of software testing. In essence, it is a constraint optimization problem, which is often solved by search methods such as backtracking algorithms. In this paper, the backtracking algorithm branch and bound and state space search in artificial intelligence are introduced to tackle the problem of path-wise test data generation. The former is utilized to explore the space of potential solutions and the latter is adopted to construct the search tree dynamically. Heuristics are employed in the look-ahead stage of the search. Dynamic variable ordering is presented with a heuristic rule to break ties, values of a variable are determined by the monotonicity analysis on branching conditions, and maintaining path consistency is achieved through analysis on the result of interval arithmetic. An optimization method is also proposed to reduce the search space. The results of empirical experiments show that the search is conducted in a basically backtrack-free manner, which ensures both test data generation with promising performance and its excellence over some currently existing static and dynamic methods in terms of coverage. The results also demonstrate that the proposed method is applicable in engineering.

  2. Analytical transmissibility based transfer path analysis for multi-energy-domain systems using four-pole parameter theory

    Science.gov (United States)

    Mashayekhi, Mohammad Jalali; Behdinan, Kamran

    2017-10-01

    The increasing demand to minimize undesired vibration and noise levels in several high-tech industries has generated a renewed interest in vibration transfer path analysis. Analyzing vibration transfer paths within a system is of crucial importance in designing an effective vibration isolation strategy. Most of the existing vibration transfer path analysis techniques are empirical which are suitable for diagnosis and troubleshooting purpose. The lack of an analytical transfer path analysis to be used in the design stage is the main motivation behind this research. In this paper an analytical transfer path analysis based on the four-pole theory is proposed for multi-energy-domain systems. Bond graph modeling technique which is an effective approach to model multi-energy-domain systems is used to develop the system model. In this paper an electro-mechanical system is used as a benchmark example to elucidate the effectiveness of the proposed technique. An algorithm to obtain the equivalent four-pole representation of a dynamical systems based on the corresponding bond graph model is also presented in this paper.

  3. The Case for Including Adverse Childhood Experiences in Child Maltreatment Education: A Path Analysis.

    Science.gov (United States)

    Bachmann, Michael; Bachmann, Brittany A

    2018-03-16

    The lifelong, negative consequences of exposure to adverse childhood experiences (ACEs) for individuals and their families are well established. To demonstrate the importance of including ACE information in child maltreatment education curricula using path analysis. Survey data examined the impact of child maltreatment education programs and knowledge about ACEs on medical practitioners' reporting habits and ability to detect maltreatment. A path diagram distinguished between the direct impact of education programs on outcome measures and the indirect effect that is mediated through knowledge of ACEs. Medical practitioners' ability to detect child maltreatment and their number of referrals to Child Protective Services (CPS). The optimized path diagram (χ 2 SB(3) = 3.9, p = 0.27; RMSEA-SB = 0.017; R 2 = 0.21, where SB is Satorra-Bentler coefficient and RMSEA is root-mean-square error of approximation) revealed the mediating variable "knowledge about ACEs" as the strongest structural effect (SB-β = 0.34) on the number of CPS referrals. It was almost twice as high as the second strongest effect of formal education programs (SB-β = 0.19). For workplace training programs, the total effect when including knowledge of ACEs was almost double as strong as the direct effect alone. Even when previous child maltreatment education was controlled for, practitioners familiar with the consequences of ACEs were significantly more likely to recognize and to report abuse to CPS. This study documented the importance of specialized training programs on ACEs, and the essential role ACE knowledge plays in the effectiveness of provider education programs.

  4. The Direct and Indirect Effects of Paliperidone Extended-release on Depressive Symptoms in Schizoaffective Disorder: A Path Analysis.

    Science.gov (United States)

    Turkoz, Ibrahim; Fu, Dong-Jing; Bossie, Cynthia A; Alphs, Larry

    2015-01-01

    This analysis evaluates improvement in symptoms of depression in patients with schizoaffective disorder administered oral paliperidone extended-release by accounting for the magnitude of direct and indirect (changes in negative and positive symptoms and worsening of extrapyramidal symptoms) treatment effects on depressive symptoms. Data for this post hoc analysis were drawn from two six-week, randomized, placebo-controlled studies of paliperidone extended-release versus placebo in adult subjects with schizoaffective disorder (N=614; NCT00412373, NCT00397033). Subjects with baseline 17-item Hamilton Rating Scale for Depression scores of 16 or greater were included. Structural equation models (path analyses) were used to separate total effects into direct and indirect effects on depressive symptoms. Change from baseline in 17-item Hamilton Rating Scale for Depression score at the Week 6 end point was the dependent variable; changes in Positive and Negative Syndrome Scale positive and negative factors and Simpson-Angus Scale (to evaluate extrapyramidal symptoms) scores were independent variables. At baseline, 332 of 614 (54.1%) subjects had a 17-item Hamilton Rating Scale for Depression score of 16 or greater. Path analysis determined that up to 26.4 percent of the paliperidone extended-release versus placebo effect on depressive symptoms may be attributed to a direct treatment effect, and 45.8 percent and 28.4 percent were mediated indirectly through improvements on positive and negative symptoms, respectively. No effects were identified as mediated through extrapyramidal symptoms changes (-0.7%). RESULTS of this analysis suggest that paliperidone's effect on depressive symptoms in subjects with schizoaffective disorder participating in two six-week, randomized, placebo-controlled studies is mediated through indirect effects (e.g., positive and negative symptom changes) and a direct treatment effect.

  5. Impact of socio-demographic factors on the mitigating actions for climate change: a path analysis with mediating effects of attitudinal variables.

    Science.gov (United States)

    Masud, Muhammad Mehedi; Akhatr, Rulia; Nasrin, Shamima; Adamu, Ibrahim Mohammed

    2017-12-01

    Socio-demographic factors play a significant role in increasing the individual's climate change awareness and in setting a favorable individual attitude towards its mitigation. To better understand how the adversative effects of climate change can be mitigated, this study attempts to investigate the impact of socio-demographic factors on the mitigating actions of the individuals (MAOI) on climate change. Qualitative data were collected from a face-to-face survey of 360 respondents in the Kuala Lumpur region of Malaysia through a close-ended questionnaire. Analysis was conducted on the mediating effects of attitudinal variables through the path model by using the SEM. Findings indicate that the socio-demographic factors such as gender, age, education, income, and ethnicity can greatly influence the individual's awareness, attitude, risk perception, and knowledge of climate change issues. The results drawn from this study also revealed that the attitudinal factors act as a mediating effect between the socio-demographic factors and the MAOI, thereby, indicating that both the socio-demographic factors and the attitudinal factors have significant effects on the MAOI towards climate change. The outcome of this study can help policy makers and other private organizations to decide on the appropriate actions to take in managing climate change effects. These actions which encompass improving basic climate change education and making the public more aware of the local dimensions of climate change are important for harnessing public engagement and support that can also stimulate climate change awareness and promote mitigating actions to n protect the environment from the impact of climate change.

  6. Fractional path planning and path tracking

    International Nuclear Information System (INIS)

    Melchior, P.; Jallouli-Khlif, R.; Metoui, B.

    2011-01-01

    This paper presents the main results of the application of fractional approach in path planning and path tracking. A new robust path planning design for mobile robot was studied in dynamic environment. The normalized attractive force applied to the robot is based on a fictitious fractional attractive potential. This method allows to obtain robust path planning despite robot mass variation. The danger level of each obstacles is characterized by the fractional order of the repulsive potential of the obstacles. Under these conditions, the robot dynamic behavior was studied by analyzing its X - Y path planning with dynamic target or dynamic obstacles. The case of simultaneously mobile obstacles and target is also considered. The influence of the robot mass variation is studied and the robustness analysis of the obtained path shows the robustness improvement due to the non integer order properties. Pre shaping approach is used to reduce system vibration in motion control. Desired systems inputs are altered so that the system finishes the requested move without residual vibration. This technique, developed by N.C. Singer and W.P.Seering, is used for flexible structure control, particularly in the aerospace field. In a previous work, this method was extended for explicit fractional derivative systems and applied to second generation CRONE control, the robustness was also studied. CRONE (the French acronym of C ommande Robuste d'Ordre Non Entier ) control system design is a frequency-domain based methodology using complex fractional integration.

  7. Primitive Path Analysis and Stress Distribution in Highly Strained Macromolecules.

    Science.gov (United States)

    Hsu, Hsiao-Ping; Kremer, Kurt

    2018-01-16

    Polymer material properties are strongly affected by entanglement effects. For long polymer chains and composite materials, they are expected to be at the origin of many technically important phenomena, such as shear thinning or the Mullins effect, which microscopically can be related to topological constraints between chains. Starting from fully equilibrated highly entangled polymer melts, we investigate the effect of isochoric elongation on the entanglement structure and force distribution of such systems. Theoretically, the related viscoelastic response usually is discussed in terms of the tube model. We relate stress relaxation in the linear and nonlinear viscoelastic regimes to a primitive path analysis (PPA) and show that tension forces both along the original paths and along primitive paths, that is, the backbone of the tube, in the stretching direction correspond to each other. Unlike homogeneous relaxation along the chain contour, the PPA reveals a so far not observed long-lived clustering of topological constraints along the chains in the deformed state.

  8. Roles of Impulsivity, Motivation, and Emotion Regulation in Procrastination – Path Analysis and Comparison Between Students and Non-students

    Directory of Open Access Journals (Sweden)

    Marek Wypych

    2018-06-01

    Full Text Available Procrastination – an irrational delay of intended actions despite expecting to be worse off – is a complex and non-homogenous phenomenon. Previous studies have found a number of correlates of procrastination, some of which seem to be particularly important. Impulsivity is closely connected to procrastination on behavioral, genetic, and neuronal levels. Difficulties in emotion regulation have also been shown to be strongly related to procrastination. Procrastination can also be considered as a motivation-based problem. To try to disentangle the connections of impulsivity, emotion regulation, and motivation to procrastination we collected data from over 600 subjects using multiple questionnaires (PPS – Pure Procrastination Scale; UPPSP – Impulsive Behavior Scale, ERQ – Emotion Regulation Questionnaire and MDT – Motivational Diagnostic Test. Structural equation modeling was performed to test several possible relationships between the measured variables. The effects of student status and age have also been investigated. The final path model was a directional model based on six explanatory variables and accounted for 70% of the variance in procrastination. Path analysis revealed that the strongest contributions to procrastination came from lack of value, delay discounting, and lack of perseverance, suggesting the involvement of motivation and impulsivity. The model also revealed the moderating role of expressive suppression between several aspects of impulsivity and procrastination. Close inspection of the paths’ weights suggests that there may be two partly competing strategies for dealing with impulsivity and negative emotions: either to suppress emotions and impulsive reactions or to react impulsively, discarding previous plans, and to procrastinate. Path invariance analysis showed the significant moderating roles of student status and age. Both in non-students and high-age groups, the path leading from suppression to procrastination

  9. Roles of Impulsivity, Motivation, and Emotion Regulation in Procrastination – Path Analysis and Comparison Between Students and Non-students

    Science.gov (United States)

    Wypych, Marek; Matuszewski, Jacek; Dragan, Wojciech Ł.

    2018-01-01

    Procrastination – an irrational delay of intended actions despite expecting to be worse off – is a complex and non-homogenous phenomenon. Previous studies have found a number of correlates of procrastination, some of which seem to be particularly important. Impulsivity is closely connected to procrastination on behavioral, genetic, and neuronal levels. Difficulties in emotion regulation have also been shown to be strongly related to procrastination. Procrastination can also be considered as a motivation-based problem. To try to disentangle the connections of impulsivity, emotion regulation, and motivation to procrastination we collected data from over 600 subjects using multiple questionnaires (PPS – Pure Procrastination Scale; UPPSP – Impulsive Behavior Scale, ERQ – Emotion Regulation Questionnaire and MDT – Motivational Diagnostic Test). Structural equation modeling was performed to test several possible relationships between the measured variables. The effects of student status and age have also been investigated. The final path model was a directional model based on six explanatory variables and accounted for 70% of the variance in procrastination. Path analysis revealed that the strongest contributions to procrastination came from lack of value, delay discounting, and lack of perseverance, suggesting the involvement of motivation and impulsivity. The model also revealed the moderating role of expressive suppression between several aspects of impulsivity and procrastination. Close inspection of the paths’ weights suggests that there may be two partly competing strategies for dealing with impulsivity and negative emotions: either to suppress emotions and impulsive reactions or to react impulsively, discarding previous plans, and to procrastinate. Path invariance analysis showed the significant moderating roles of student status and age. Both in non-students and high-age groups, the path leading from suppression to procrastination was insignificant

  10. The effect of PLS regression in PLS path model estimation when multicollinearity is present

    DEFF Research Database (Denmark)

    Nielsen, Rikke; Kristensen, Kai; Eskildsen, Jacob

    PLS path modelling has previously been found to be robust to multicollinearity both between latent variables and between manifest variables of a common latent variable (see e.g. Cassel et al. (1999), Kristensen, Eskildsen (2005), Westlund et al. (2008)). However, most of the studies investigate...... models with relatively few variables and very simple dependence structures compared to the models that are often estimated in practical settings. A recent study by Nielsen et al. (2009) found that when model structure is more complex, PLS path modelling is not as robust to multicollinearity between...... latent variables as previously assumed. A difference in the standard error of path coefficients of as much as 83% was found between moderate and severe levels of multicollinearity. Large differences were found not only for large path coefficients, but also for small path coefficients and in some cases...

  11. Vulnerabilities, Influences and Interaction Paths: Failure Data for Integrated System Risk Analysis

    Science.gov (United States)

    Malin, Jane T.; Fleming, Land

    2006-01-01

    We describe graph-based analysis methods for identifying and analyzing cross-subsystem interaction risks from subsystem connectivity information. By discovering external and remote influences that would be otherwise unexpected, these methods can support better communication among subsystem designers at points of potential conflict and to support design of more dependable and diagnosable systems. These methods identify hazard causes that can impact vulnerable functions or entities if propagated across interaction paths from the hazard source to the vulnerable target. The analysis can also assess combined impacts of And-Or trees of disabling influences. The analysis can use ratings of hazards and vulnerabilities to calculate cumulative measures of the severity and importance. Identification of cross-subsystem hazard-vulnerability pairs and propagation paths across subsystems will increase coverage of hazard and risk analysis and can indicate risk control and protection strategies.

  12. An Optimization-Driven Analysis Pipeline to Uncover Biomarkers and Signaling Paths: Cervix Cancer

    Directory of Open Access Journals (Sweden)

    Enery Lorenzo

    2015-05-01

    Full Text Available Establishing how a series of potentially important genes might relate to each other is relevant to understand the origin and evolution of illnesses, such as cancer. High‑throughput biological experiments have played a critical role in providing information in this regard. A special challenge, however, is that of trying to conciliate information from separate microarray experiments to build a potential genetic signaling path. This work proposes a two-step analysis pipeline, based on optimization, to approach meta-analysis aiming to build a proxy for a genetic signaling path.

  13. Postoperative pain after manual and mechanical glide path: a randomized clinical trial.

    Science.gov (United States)

    Pasqualini, Damiano; Mollo, Livio; Scotti, Nicola; Cantatore, Giuseppe; Castellucci, Arnaldo; Migliaretti, Giuseppe; Berutti, Elio

    2012-01-01

    This prospective randomized clinical trial evaluated the incidence of postoperative pain after glide path performed with PathFile (PF) (Dentsply Maillefer, Ballaigues, Switzerland) versus stainless-steel K-file (KF). In 149 subjects, the mechanical glide path was performed with nickel-titanium (NiTi) rotary PF; in 146 subjects, the manual glide path was performed with stainless-steel KFs. Postoperative pain, analgesics consumption, and the number of days to complete pain resolution were evaluated in the following 7 days. An analysis of variance model for repeated measures was used to compare the variation of pain-scale values (P < .05). The Student's t test for continuous variables normally distributed, the nonparametric Mann-Whitney U test for the nonnormally distributed variables, and the chi-square test for dichotomous variables were used (P < .05). Despite homogeneous baseline conditions at diagnosis, tooth type, pain prevalence, and scores, the postoperative pain prevalence curves in PF group evidenced a more favorable trend in terms of time to pain resolution compared with the KF group (P = .004). The difference was also evident in the model adjusted for analgesics consumption in both groups (P = .012). The mean analgesics intake per subject was significantly higher in the KF group (3.7 ± 2.2) compared with the PF group (2 ± 1.7) (P < .001). Mean pain stop values were also significantly higher in the KF group (2.7) compared with the PF group (1.7) (P = .001). The glide path with NiTi Rotary PF leads to less postoperative pain and faster symptom resolution. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. The Case for Including Adverse Childhood Experiences in Child Maltreatment Education: A Path Analysis

    Science.gov (United States)

    Bachmann, Michael; Bachmann, Brittany A

    2018-01-01

    Context The lifelong, negative consequences of exposure to adverse childhood experiences (ACEs) for individuals and their families are well established. Objective To demonstrate the importance of including ACE information in child maltreatment education curricula using path analysis. Design Survey data examined the impact of child maltreatment education programs and knowledge about ACEs on medical practitioners’ reporting habits and ability to detect maltreatment. A path diagram distinguished between the direct impact of education programs on outcome measures and the indirect effect that is mediated through knowledge of ACEs. Main Outcome Measures Medical practitioners’ ability to detect child maltreatment and their number of referrals to Child Protective Services (CPS). Results The optimized path diagram (χ2SB(3) = 3.9, p = 0.27; RMSEA-SB = 0.017; R2 = 0.21, where SB is Satorra-Bentler coefficient and RMSEA is root-mean-square error of approximation) revealed the mediating variable “knowledge about ACEs” as the strongest structural effect (SB-β = 0.34) on the number of CPS referrals. It was almost twice as high as the second strongest effect of formal education programs (SB-β = 0.19). For workplace training programs, the total effect when including knowledge of ACEs was almost double as strong as the direct effect alone. Even when previous child maltreatment education was controlled for, practitioners familiar with the consequences of ACEs were significantly more likely to recognize and to report abuse to CPS. Conclusion This study documented the importance of specialized training programs on ACEs, and the essential role ACE knowledge plays in the effectiveness of provider education programs. PMID:29616910

  15. Path analysis and multi-criteria decision making: an approach for multivariate model selection and analysis in health.

    Science.gov (United States)

    Vasconcelos, A G; Almeida, R M; Nobre, F F

    2001-08-01

    This paper introduces an approach that includes non-quantitative factors for the selection and assessment of multivariate complex models in health. A goodness-of-fit based methodology combined with fuzzy multi-criteria decision-making approach is proposed for model selection. Models were obtained using the Path Analysis (PA) methodology in order to explain the interrelationship between health determinants and the post-neonatal component of infant mortality in 59 municipalities of Brazil in the year 1991. Socioeconomic and demographic factors were used as exogenous variables, and environmental, health service and agglomeration as endogenous variables. Five PA models were developed and accepted by statistical criteria of goodness-of fit. These models were then submitted to a group of experts, seeking to characterize their preferences, according to predefined criteria that tried to evaluate model relevance and plausibility. Fuzzy set techniques were used to rank the alternative models according to the number of times a model was superior to ("dominated") the others. The best-ranked model explained above 90% of the endogenous variables variation, and showed the favorable influences of income and education levels on post-neonatal mortality. It also showed the unfavorable effect on mortality of fast population growth, through precarious dwelling conditions and decreased access to sanitation. It was possible to aggregate expert opinions in model evaluation. The proposed procedure for model selection allowed the inclusion of subjective information in a clear and systematic manner.

  16. Path analysis of risk factors leading to premature birth.

    Science.gov (United States)

    Fields, S J; Livshits, G; Sirotta, L; Merlob, P

    1996-01-01

    The present study tested whether various sociodemographic, anthropometric, behavioral, and medical/physiological factors act in a direct or indirect manner on the risk of prematurity using path analysis on a sample of Israeli births. The path model shows that medical complications, primarily toxemia, chorioammionitis, and a previous low birth weight delivery directly and significantly act on the risk of prematurity as do low maternal pregnancy weight gain and ethnicity. Other medical complications, including chronic hypertension, preclampsia, and placental abruption, although significantly correlated with prematurity, act indirectly on prematurity through toxemia. The model further shows that the commonly accepted sociodemographic, anthropometric, and behavioral risk factors act by modifying the development of medical complications that lead to prematurity as opposed to having a direct effect on premature delivery. © 1996 Wiley-Liss, Inc. Copyright © 1996 Wiley-Liss, Inc.

  17. Shortest-path network analysis is a useful approach toward identifying genetic determinants of longevity.

    Directory of Open Access Journals (Sweden)

    J R Managbanag

    Full Text Available BACKGROUND: Identification of genes that modulate longevity is a major focus of aging-related research and an area of intense public interest. In addition to facilitating an improved understanding of the basic mechanisms of aging, such genes represent potential targets for therapeutic intervention in multiple age-associated diseases, including cancer, heart disease, diabetes, and neurodegenerative disorders. To date, however, targeted efforts at identifying longevity-associated genes have been limited by a lack of predictive power, and useful algorithms for candidate gene-identification have also been lacking. METHODOLOGY/PRINCIPAL FINDINGS: We have utilized a shortest-path network analysis to identify novel genes that modulate longevity in Saccharomyces cerevisiae. Based on a set of previously reported genes associated with increased life span, we applied a shortest-path network algorithm to a pre-existing protein-protein interaction dataset in order to construct a shortest-path longevity network. To validate this network, the replicative aging potential of 88 single-gene deletion strains corresponding to predicted components of the shortest-path longevity network was determined. Here we report that the single-gene deletion strains identified by our shortest-path longevity analysis are significantly enriched for mutations conferring either increased or decreased replicative life span, relative to a randomly selected set of 564 single-gene deletion strains or to the current data set available for the entire haploid deletion collection. Further, we report the identification of previously unknown longevity genes, several of which function in a conserved longevity pathway believed to mediate life span extension in response to dietary restriction. CONCLUSIONS/SIGNIFICANCE: This work demonstrates that shortest-path network analysis is a useful approach toward identifying genetic determinants of longevity and represents the first application of

  18. Quantum circuit dynamics via path integrals: Is there a classical action for discrete-time paths?

    Science.gov (United States)

    Penney, Mark D.; Enshan Koh, Dax; Spekkens, Robert W.

    2017-07-01

    It is straightforward to compute the transition amplitudes of a quantum circuit using the sum-over-paths methodology when the gates in the circuit are balanced, where a balanced gate is one for which all non-zero transition amplitudes are of equal magnitude. Here we consider the question of whether, for such circuits, the relative phases of different discrete-time paths through the configuration space can be defined in terms of a classical action, as they are for continuous-time paths. We show how to do so for certain kinds of quantum circuits, namely, Clifford circuits where the elementary systems are continuous-variable systems or discrete systems of odd-prime dimension. These types of circuit are distinguished by having phase-space representations that serve to define their classical counterparts. For discrete systems, the phase-space coordinates are also discrete variables. We show that for each gate in the generating set, one can associate a symplectomorphism on the phase-space and to each of these one can associate a generating function, defined on two copies of the configuration space. For discrete systems, the latter association is achieved using tools from algebraic geometry. Finally, we show that if the action functional for a discrete-time path through a sequence of gates is defined using the sum of the corresponding generating functions, then it yields the correct relative phases for the path-sum expression. These results are likely to be relevant for quantizing physical theories where time is fundamentally discrete, characterizing the classical limit of discrete-time quantum dynamics, and proving complexity results for quantum circuits.

  19. Path analysis of the energy density of wood in eucalyptus clones.

    Science.gov (United States)

    Couto, A M; Teodoro, P E; Trugilho, P F

    2017-03-16

    Path analysis has been used for establishing selection criteria in genetic breeding programs for several crops. However, it has not been used in eucalyptus breeding programs yet. In the present study, we aimed to identify the wood technology traits that could be used as the criteria for direct and indirect selection of eucalyptus genotypes with high energy density of wood. Twenty-four eucalyptus clones were evaluated in a completely randomized design with five replications. The following traits were assessed: basic wood density, total extractives, lignin content, ash content, nitrogen content, carbon content, hydrogen content, sulfur content, oxygen content, higher calorific power, holocellulose, and energy density. After verifying the variability of all evaluated traits among the clones, a two-dimensional correlation network was used to determine the phenotypic patterns among them. The obtained coefficient of determination (0.94) presented a higher magnitude in relation to the effect of the residual variable, and it served as an excellent model for explaining the genetic effects related to the variations observed in the energy density of wood in all eucalyptus clones. However, for future studies, we recommend evaluating other traits, especially the morphological traits, because of the greater ease in their measurement. Selecting clones with high basic density is the most promising strategy for eucalyptus breeding programs that aim to increase the energy density of wood because of its high heritability and magnitude of the cause-and-effect relationship with this trait.

  20. Path optimization method for the sign problem

    Directory of Open Access Journals (Sweden)

    Ohnishi Akira

    2018-01-01

    Full Text Available We propose a path optimization method (POM to evade the sign problem in the Monte-Carlo calculations for complex actions. Among many approaches to the sign problem, the Lefschetz-thimble path-integral method and the complex Langevin method are promising and extensively discussed. In these methods, real field variables are complexified and the integration manifold is determined by the flow equations or stochastically sampled. When we have singular points of the action or multiple critical points near the original integral surface, however, we have a risk to encounter the residual and global sign problems or the singular drift term problem. One of the ways to avoid the singular points is to optimize the integration path which is designed not to hit the singular points of the Boltzmann weight. By specifying the one-dimensional integration-path as z = t +if(t(f ϵ R and by optimizing f(t to enhance the average phase factor, we demonstrate that we can avoid the sign problem in a one-variable toy model for which the complex Langevin method is found to fail. In this proceedings, we propose POM and discuss how we can avoid the sign problem in a toy model. We also discuss the possibility to utilize the neural network to optimize the path.

  1. The Best Path Analysis in Military Highway Transport Based on DEA and Multiobjective Fuzzy Decision-Making

    Directory of Open Access Journals (Sweden)

    Wu Juan

    2014-01-01

    Full Text Available Military transport path selection directly affects the transport speed, efficiency, and safety. To a certain degree, the results of the path selection determine success or failure of the war situation. The purpose of this paper is to propose a model based on DEA (data envelopment analysis and multiobjective fuzzy decision-making for path selection. The path decision set is established according to a search algorithm based on overlapping section punishment. Considering the influence of various fuzzy factors, the model of optimal path is constructed based on DEA and multitarget fuzzy decision-making theory, where travel time, transport risk, quick response capability, and transport cost constitute the evaluation target set. A reasonable path set can be calculated and sorted according to the comprehensive scores of the paths. The numerical results show that the model and the related algorithms are effective for path selection of military transport.

  2. Diversion path analysis handbook. Volume I. Methodology

    International Nuclear Information System (INIS)

    Maltese, M.D.K.; Goodwin, K.E.; Schleter, J.C.

    1976-10-01

    Diversion Path Analysis (DPA) is a procedure for analyzing internal controls of a facility in order to identify vulnerabilities to successful diversion of material by an adversary. The internal covert threat is addressed but the results are also applicable to the external overt threat. The diversion paths are identified. Complexity parameters include records alteration or falsification, multiple removals of sub-threshold quantities, collusion, and access authorization of the individual. Indicators, or data elements and information of significance to detection of unprevented theft, are identified by means of DPA. Indicator sensitivity is developed in terms of the threshold quantity, the elapsed time between removal and indication and the degree of localization of facility area and personnel given by the indicator. Evaluation of facility internal controls in light of these sensitivities defines the capability of interrupting identified adversary action sequences related to acquisition of material at fixed sites associated with the identified potential vulnerabilities. Corrective measures can, in many cases, also be prescribed for management consideration and action. DPA theory and concepts have been developing over the last several years, and initial field testing proved both the feasibility and practicality of the procedure. Follow-on implementation testing verified the ability of facility personnel to perform DPA

  3. Antibody Heavy Chain Variable Domains of Different Germline Gene Origins Diversify through Different Paths

    Directory of Open Access Journals (Sweden)

    Ufuk Kirik

    2017-11-01

    Full Text Available B cells produce antibodies, key effector molecules in health and disease. They mature their properties, including their affinity for antigen, through hypermutation events; processes that involve, e.g., base substitution, codon insertion and deletion, often in association with an isotype switch. Investigations of antibody evolution define modes whereby particular antibody responses are able to form, and such studies provide insight important for instance for development of efficient vaccines. Antibody evolution is also used in vitro for the design of antibodies with improved properties. To better understand the basic concepts of antibody evolution, we analyzed the mutational paths, both in terms of amino acid substitution and insertions and deletions, taken by antibodies of the IgG isotype. The analysis focused on the evolution of the heavy chain variable domain of sets of antibodies, each with an origin in 1 of 11 different germline genes representing six human heavy chain germline gene subgroups. Investigated genes were isolated from cells of human bone marrow, a major site of antibody production, and characterized by next-generation sequencing and an in-house bioinformatics pipeline. Apart from substitutions within the complementarity determining regions, multiple framework residues including those in protein cores were targets of extensive diversification. Diversity, both in terms of substitutions, and insertions and deletions, in antibodies is focused to different positions in the sequence in a germline gene-unique manner. Altogether, our findings create a framework for understanding patterns of evolution of antibodies from defined germline genes.

  4. Path analysis for physiological traits that influence seed germination of Passiflora edulis f. flavicarpa Deg

    Directory of Open Access Journals (Sweden)

    Erneida Coelho de Araújo

    2007-01-01

    Full Text Available The quality of yellow passion fruit seed is determined by fruit storage and the duration of this period. Two orthree harvest dates can thereby be defined to obtain maximum quality. This study aimed to obtain estimates of phenotype,genotype and residual correlation coefficients and evaluate the direct and indirect effects (path analysis of genotype correlationsin seed extracted from fruits stored for 7, 14 and 21 days at cooled (8 ºC and at environment temperature (25 ºC. Thevariables accelerated aging and moisture content explained the higher germination percentage in the refrigerated environment.However, in natural conditions, the variables dry matter and electric conductivity influenced seed germination percentagestrongly, evidencing that the indirect effects of accelerated aging, electric conductivity and weight reduction had the greatestinfluence on dry matter.

  5. Time-optimal path planning in uncertain flow fields using ensemble method

    KAUST Repository

    Wang, Tong

    2016-01-06

    An ensemble-based approach is developed to conduct time-optimal path planning in unsteady ocean currents under uncertainty. We focus our attention on two-dimensional steady and unsteady uncertain flows, and adopt a sampling methodology that is well suited to operational forecasts, where a set deterministic predictions is used to model and quantify uncertainty in the predictions. In the operational setting, much about dynamics, topography and forcing of the ocean environment is uncertain, and as a result a single path produced by a model simulation has limited utility. To overcome this limitation, we rely on a finitesize ensemble of deterministic forecasts to quantify the impact of variability in the dynamics. The uncertainty of flow field is parametrized using a finite number of independent canonical random variables with known densities, and the ensemble is generated by sampling these variables. For each the resulting realizations of the uncertain current field, we predict the optimal path by solving a boundary value problem (BVP), based on the Pontryagin maximum principle. A family of backward-in-time trajectories starting at the end position is used to generate suitable initial values for the BVP solver. This allows us to examine and analyze the performance of sampling strategy, and develop insight into extensions dealing with regional or general circulation models. In particular, the ensemble method enables us to perform a statistical analysis of travel times, and consequently develop a path planning approach that accounts for these statistics. The proposed methodology is tested for a number of scenarios. We first validate our algorithms by reproducing simple canonical solutions, and then demonstrate our approach in more complex flow fields, including idealized, steady and unsteady double-gyre flows.

  6. Quantum circuit dynamics via path integrals: Is there a classical action for discrete-time paths?

    International Nuclear Information System (INIS)

    Penney, Mark D; Koh, Dax Enshan; Spekkens, Robert W

    2017-01-01

    It is straightforward to compute the transition amplitudes of a quantum circuit using the sum-over-paths methodology when the gates in the circuit are balanced, where a balanced gate is one for which all non-zero transition amplitudes are of equal magnitude. Here we consider the question of whether, for such circuits, the relative phases of different discrete-time paths through the configuration space can be defined in terms of a classical action, as they are for continuous-time paths. We show how to do so for certain kinds of quantum circuits, namely, Clifford circuits where the elementary systems are continuous-variable systems or discrete systems of odd-prime dimension. These types of circuit are distinguished by having phase-space representations that serve to define their classical counterparts. For discrete systems, the phase-space coordinates are also discrete variables. We show that for each gate in the generating set, one can associate a symplectomorphism on the phase-space and to each of these one can associate a generating function, defined on two copies of the configuration space. For discrete systems, the latter association is achieved using tools from algebraic geometry. Finally, we show that if the action functional for a discrete-time path through a sequence of gates is defined using the sum of the corresponding generating functions, then it yields the correct relative phases for the path-sum expression. These results are likely to be relevant for quantizing physical theories where time is fundamentally discrete, characterizing the classical limit of discrete-time quantum dynamics, and proving complexity results for quantum circuits. (paper)

  7. Pedestrian paths: why path-dependence theory leaves health policy analysis lost in space.

    Science.gov (United States)

    Brown, Lawrence D

    2010-08-01

    Path dependence, a model first advanced to explain puzzles in the diffusion of technology, has lately won allegiance among analysts of the politics of public policy, including health care policy. Though the central premise of the model--that past events and decisions shape options for innovation in the present and future--is indisputable (indeed path dependence is, so to speak, too shallow to be false), the approach, at least as applied to health policy, suffers from ambiguities that undercut its claims to illuminate policy projects such as managed care, on which this article focuses. Because path dependence adds little more than marginal value to familiar images of the politics of policy--incrementalism, for one--analysts might do well to put it on the back burner and pursue instead "thick descriptions" that help them to distinguish different degrees of openness to exogenous change among diverse policy arenas.

  8. Intimate partner violence in the eastern part of Iran: a path analysis of risk factors.

    Science.gov (United States)

    Moghaddam Hosseini, Vahideh; Asadi, Zahra Sadat; Akaberi, Arash; Hashemian, Masoumeh

    2013-08-01

    Intimate partner violence against women is a widespread phenomenon that is the cause of many deleterious health and social consequences. This study examines the impact of some risk factors on partner violence in the eastern region of Iran, using path analysis. The study used a population-based cross sectional study design. In this study, 251 married women who were referred to the health centers were selected through a proportionally stratified and randomized sampling method. Domestic violence was measured using Conflict Tactics Scale and the socio-demographic variable was assessed by a self-report questionnaire. Bayesian Structural Equation Modeling was used for evaluating the overall path analysis and the direct and indirect p-value was estimated by Bootstrap method. AMOS and SPSS software were used to analyze data. The prevalence of overall violence was 78.1%, with 37.8% and 0.8% of women reporting minor and severe violence, respectively, and 39.8% reporting both severe and minor forms of violence. Psychological violence was the most common type of violence reported (66.5%). The model showed that husbands' drug abuse and women's higher level of education compared to their husbands were the first and second most important factors that significantly and directly influenced the violence. The women's attitude, however, had the least effect on the violence. The findings indicated that higher educated women and women with addicted husbands were more likely to experience violence. Treating the drug abuse disorders, especially mental disorders, using behavioral couple's therapy, as well as modifying certain traditional and cultural biases against women's empowerment are suggested.

  9. A Path Analysis of the Effects of Principal Professional Orientation towards Leadership, Professional Teacher Behavior, and School Academic Optimism on School Reading Achievement

    Directory of Open Access Journals (Sweden)

    Roxanne M. Mitchell

    2016-02-01

    Full Text Available This study tested the effects of the principal’s professional orientation towards leadership/enabling school structure (ESS on two mediating variables, school academic optimism (SAO and professional teacher behavior (PTB, on the outcome variable school reading achievement (RA. Data were drawn from a sample of 54 schools (including 45 elementary schools and nine middle schools; the school was the unit of analysis. Data analysis supported a path to RA in which a structural variable, ESS was the immediate antecedent of SAO and PTB. Two control variables, school level and SES, were included in the model. SES had a significant effect on SAO but not on PTB. School level had a negative effect on both PTB and SAO suggesting that both variables were higher in elementary school and declined in middle school. SES paired with SAO in predicting RA. As expected, SAO had a greater effect on RA than SES. The significance of the findings lies in the confirmation of SAO as an important influence on RA and in demonstrating the importance of ESS in establishing a context in which AO and PTB can flourish.

  10. comparative analysis and implementation of dijkstra's shortest path

    African Journals Online (AJOL)

    user

    path problem requires finding a single shortest-path between given vertices s and t; ... Bridge in 1735, [5 – 10]. This problem led to the .... their advancements from new design paradigms, data structures ..... .

  11. Analysis on Human Blockage Path Loss and Shadow Fading in Millimeter-Wave Band

    Directory of Open Access Journals (Sweden)

    Hongmei Zhao

    2017-01-01

    Full Text Available Millimeter-wave (Mm-w is the trend of communication development in the future; users who carry mobile communication equipment could be blocked by others in a crowded population environment. Based on Shooting and Bouncing Ray (SBR method and setting up different orientation receivers (RX, population density, and people fabric property at 28 GHz and 38 GHz, simulating experimental scene similar to station square by Wireless Insite software, we use least square method to do linear-regression analysis for path loss and build path loss model. The result shows that the path loss index has a certain change in the different frequency, orientation receivers, population density, and people fabric. The path loss index of RouteC1 and RouteA2 has an obvious change in the central transmitter (TX. Each route shadow fading obeys Gaussian distribution whose mean is 0. This paper’s result has a theoretical guiding for designing the communication system in a crowded population environment.

  12. Diversion Path Analysis handbook. Volume 3 (of 4 volumes). Computer Program 1

    International Nuclear Information System (INIS)

    Schleter, J.C.

    1978-11-01

    The FORTRAN IV computer program, DPA Computer Program 1 (DPACP-1), is used to assemble and tabulate the data for Specific Diversion Paths (SDPs) identified when performing a Diversion Path Analysis (DPA) in accord with the methodology given in Volume 1. The program requires 255498 bytes exclusive of the operating system. The data assembled and tabulated by DPACP-1 are used by the DPA team to assist in analyzing vulnerabilities, in a plant's material control and material accounting subsystems, to diversion of special nuclear material (SNM) by a knowledgable insider. Based on this analysis, the DPA team can identify, and propose to plant management, modifications to the plant's safeguards system that would eliminate, or reduce the severity of, the identified vulnerabilities. The data are also used by plant supervision when investigating a potential diversion

  13. Interactions of information transfer along separable causal paths

    Science.gov (United States)

    Jiang, Peishi; Kumar, Praveen

    2018-04-01

    Complex systems arise as a result of interdependences between multiple variables, whose causal interactions can be visualized in a time-series graph. Transfer entropy and information partitioning approaches have been used to characterize such dependences. However, these approaches capture net information transfer occurring through a multitude of pathways involved in the interaction and as a result mask our ability to discern the causal interaction within a subgraph of interest through specific pathways. We build on recent developments of momentary information transfer along causal paths proposed by Runge [Phys. Rev. E 92, 062829 (2015), 10.1103/PhysRevE.92.062829] to develop a framework for quantifying information partitioning along separable causal paths. Momentary information transfer along causal paths captures the amount of information transfer between any two variables lagged at two specific points in time. Our approach expands this concept to characterize the causal interaction in terms of synergistic, unique, and redundant information transfer through separable causal paths. Through a graphical model, we analyze the impact of the separable and nonseparable causal paths and the causality structure embedded in the graph as well as the noise effect on information partitioning by using synthetic data generated from two coupled logistic equation models. Our approach can provide a valuable reference for an autonomous information partitioning along separable causal paths which form a causal subgraph influencing a target.

  14. Path and correlation analysis of perennial ryegrass (Lolium perenne L.) seed yield components

    DEFF Research Database (Denmark)

    Abel, Simon; Gislum, René; Boelt, Birte

    2017-01-01

    Maximum perennial ryegrass seed production potential is substantially greater than harvested yields with harvested yields representing only 20% of calculated potential. Similar to wheat, maize and other agriculturally important crops, seed yield is highly dependent on a number of interacting seed...... yield components. This research was performed to apply and describe path analysis of perennial ryegrass seed yield components in relation to harvested seed yields. Utilising extensive yield components which included subdividing reproductive inflorescences into five size categories, path analysis...... was undertaken assuming a unidirectional causal-admissible relationship between seed yield components and harvested seed yield in six commercial seed production fields. Both spikelets per inflorescence and florets per spikelet had a significant (p seed yield; however, total...

  15. PP: A graphics post-processor for the EQ6 reaction path code

    International Nuclear Information System (INIS)

    Stockman, H.W.

    1994-09-01

    The PP code is a graphics post-processor and plotting program for EQ6, a popular reaction-path code. PP runs on personal computers, allocates memory dynamically, and can handle very large reaction path runs. Plots of simple variable groups, such as fluid and solid phase composition, can be obtained with as few as two keystrokes. Navigation through the list of reaction path variables is simple and efficient. Graphics files can be exported for inclusion in word processing documents and spreadsheets, and experimental data may be imported and superposed on the reaction path runs. The EQ6 thermodynamic database can be searched from within PP, to simplify interpretation of complex plots

  16. A new algorithm for least-cost path analysis by correcting digital elevation models of natural landscapes

    Science.gov (United States)

    Baek, Jieun; Choi, Yosoon

    2017-04-01

    Most algorithms for least-cost path analysis usually calculate the slope gradient between the source cell and the adjacent cells to reflect the weights for terrain slope into the calculation of travel costs. However, these algorithms have limitations that they cannot analyze the least-cost path between two cells when obstacle cells with very high or low terrain elevation exist between the source cell and the target cell. This study presents a new algorithm for least-cost path analysis by correcting digital elevation models of natural landscapes to find possible paths satisfying the constraint of maximum or minimum slope gradient. The new algorithm calculates the slope gradient between the center cell and non-adjacent cells using the concept of extended move-sets. If the algorithm finds possible paths between the center cell and non-adjacent cells with satisfying the constraint of slope condition, terrain elevation of obstacle cells existing between two cells is corrected from the digital elevation model. After calculating the cumulative travel costs to the destination by reflecting the weight of the difference between the original and corrected elevations, the algorithm analyzes the least-cost path. The results of applying the proposed algorithm to the synthetic data sets and the real-world data sets provide proof that the new algorithm can provide more accurate least-cost paths than other conventional algorithms implemented in commercial GIS software such as ArcGIS.

  17. A Novel Real-Time Path Servo Control of a Hardware-in-the-Loop for a Large-Stroke Asymmetric Rod-Less Pneumatic System under Variable Loads

    Directory of Open Access Journals (Sweden)

    Hao-Ting Lin

    2017-06-01

    Full Text Available This project aims to develop a novel large stroke asymmetric pneumatic servo system of a hardware-in-the-loop for path tracking control under variable loads based on the MATLAB Simulink real-time system. High pressure compressed air provided by the air compressor is utilized for the pneumatic proportional servo valve to drive the large stroke asymmetric rod-less pneumatic actuator. Due to the pressure differences between two chambers, the pneumatic actuator will operate. The highly nonlinear mathematical models of the large stroke asymmetric pneumatic system were analyzed and developed. The functional approximation technique based on the sliding mode controller (FASC is developed as a controller to solve the uncertain time-varying nonlinear system. The MATLAB Simulink real-time system was a main control unit of a hardware-in-the-loop system proposed to establish driver blocks for analog and digital I/O, a linear encoder, a CPU and a large stroke asymmetric pneumatic rod-less system. By the position sensor, the position signals of the cylinder will be measured immediately. The measured signals will be viewed as the feedback signals of the pneumatic servo system for the study of real-time positioning control and path tracking control. Finally, real-time control of a large stroke asymmetric pneumatic servo system with measuring system, a large stroke asymmetric pneumatic servo system, data acquisition system and the control strategy software will be implemented. Thus, upgrading the high position precision and the trajectory tracking performance of the large stroke asymmetric pneumatic servo system will be realized to promote the high position precision and path tracking capability. Experimental results show that fifth order paths in various strokes and the sine wave path are successfully implemented in the test rig. Also, results of variable loads under the different angle were implemented experimentally.

  18. A Novel Real-Time Path Servo Control of a Hardware-in-the-Loop for a Large-Stroke Asymmetric Rod-Less Pneumatic System under Variable Loads.

    Science.gov (United States)

    Lin, Hao-Ting

    2017-06-04

    This project aims to develop a novel large stroke asymmetric pneumatic servo system of a hardware-in-the-loop for path tracking control under variable loads based on the MATLAB Simulink real-time system. High pressure compressed air provided by the air compressor is utilized for the pneumatic proportional servo valve to drive the large stroke asymmetric rod-less pneumatic actuator. Due to the pressure differences between two chambers, the pneumatic actuator will operate. The highly nonlinear mathematical models of the large stroke asymmetric pneumatic system were analyzed and developed. The functional approximation technique based on the sliding mode controller (FASC) is developed as a controller to solve the uncertain time-varying nonlinear system. The MATLAB Simulink real-time system was a main control unit of a hardware-in-the-loop system proposed to establish driver blocks for analog and digital I/O, a linear encoder, a CPU and a large stroke asymmetric pneumatic rod-less system. By the position sensor, the position signals of the cylinder will be measured immediately. The measured signals will be viewed as the feedback signals of the pneumatic servo system for the study of real-time positioning control and path tracking control. Finally, real-time control of a large stroke asymmetric pneumatic servo system with measuring system, a large stroke asymmetric pneumatic servo system, data acquisition system and the control strategy software will be implemented. Thus, upgrading the high position precision and the trajectory tracking performance of the large stroke asymmetric pneumatic servo system will be realized to promote the high position precision and path tracking capability. Experimental results show that fifth order paths in various strokes and the sine wave path are successfully implemented in the test rig. Also, results of variable loads under the different angle were implemented experimentally.

  19. Path-based Queries on Trajectory Data

    DEFF Research Database (Denmark)

    Krogh, Benjamin Bjerre; Pelekis, Nikos; Theodoridis, Yannis

    2014-01-01

    In traffic research, management, and planning a number of path-based analyses are heavily used, e.g., for computing turn-times, evaluating green waves, or studying traffic flow. These analyses require retrieving the trajectories that follow the full path being analyzed. Existing path queries cannot...... sufficiently support such path-based analyses because they retrieve all trajectories that touch any edge in the path. In this paper, we define and formalize the strict path query. This is a novel query type tailored to support path-based analysis, where trajectories must follow all edges in the path...... a specific path by only retrieving data from the first and last edge in the path. To correctly answer strict path queries existing network-constrained trajectory indexes must retrieve data from all edges in the path. An extensive performance study of NETTRA using a very large real-world trajectory data set...

  20. Evaluation of Fertility Model by Using Path Analysis in Hamadan City in 2004

    Directory of Open Access Journals (Sweden)

    M. Mahdi Akhgar

    2015-07-01

    Full Text Available Introduction & Objective: The most important indicator of population growth is fertility. Fertil-ity is influenced by selection of individual, social, economic, demographic, cultural and bio-logical factors. The purpose of this study is to investigate the factors affecting fertility (num-ber of live births. Materials & Methods: This was a cross- sectional study of the correlation matrix, which is based on a sample of 500 households in the two-stage random sampling method. First, a question-naire was adjusted and then was provided to interviewers for recording some demographics information and birthrate. To examine the relationship between these variables and fertility model, the most important influential variables on fertility were selected based on the theo-retical model and using socio-economic and demographic variables influencing on fertility. The data were then analyzed by the path analysis using LISREL software. Results: Mean±SD of parity in 500 married women was 2.18±0.904 in Hamadan city. Among the variables, couple education (total effect -0.421 and the number of unwanted pregnancy (total effect 0.27 had the highest effect on fertility, respectively; while husband’s marriage age (total effect -0.00365 had the lowest effects on parity. Conclusion: This study shows that high education is a deterrent factor to live births and also shows that the rise of live births is unwanted among families. Also, it can be concluded from the findings of this study that culture of trend towards early marriage and childbearing which are associated with the promotion of education for women and men can significantly increase the pregnancy order to prevent the lack of active and aging population. (Sci J Hamadan Univ Med Sci 2015; 22 (2: 122-128

  1. Path planning in uncertain flow fields using ensemble method

    KAUST Repository

    Wang, Tong

    2016-08-20

    An ensemble-based approach is developed to conduct optimal path planning in unsteady ocean currents under uncertainty. We focus our attention on two-dimensional steady and unsteady uncertain flows, and adopt a sampling methodology that is well suited to operational forecasts, where an ensemble of deterministic predictions is used to model and quantify uncertainty. In an operational setting, much about dynamics, topography, and forcing of the ocean environment is uncertain. To address this uncertainty, the flow field is parametrized using a finite number of independent canonical random variables with known densities, and the ensemble is generated by sampling these variables. For each of the resulting realizations of the uncertain current field, we predict the path that minimizes the travel time by solving a boundary value problem (BVP), based on the Pontryagin maximum principle. A family of backward-in-time trajectories starting at the end position is used to generate suitable initial values for the BVP solver. This allows us to examine and analyze the performance of the sampling strategy and to develop insight into extensions dealing with general circulation ocean models. In particular, the ensemble method enables us to perform a statistical analysis of travel times and consequently develop a path planning approach that accounts for these statistics. The proposed methodology is tested for a number of scenarios. We first validate our algorithms by reproducing simple canonical solutions, and then demonstrate our approach in more complex flow fields, including idealized, steady and unsteady double-gyre flows.

  2. Practicality of diversion path analysis

    International Nuclear Information System (INIS)

    Murphey, W.M.; Schleter, J.C.

    1974-07-01

    One can define the safeguards system for nuclear material as the set of all protective actions taken to prevent or to deter attempts to divert nuclear material to unauthorized use. Maintenance of effective safeguards requires a program for routine assessment of plant safeguards systems in terms of their capabilities to satisfy safeguards aims. Plant internal control systems provide capabilities for detection of unprevented diversion and can provide assurance that diversion has not occurred. A procedure called Diversion Path Analysis (DPA) enables routine assessment of the capabilities of internal control systems in this regard and identification of safeguards problem areas in a plant. A framework for safeguards system design is also provided which will allow flexibility to accommodate individual plant circumstances while maintaining acceptable diversion detection capability. The steps of the procedure are described and the practicality of the analytical method is shown by referring to a demonstration test for a high throughput process where plant personnel were major participants. The boundary conditions for the demonstration case are given, along with some conclusions about the general procedure. (U.S.)

  3. Software news and update PyFrag - Streamlining your reaction path analysis

    NARCIS (Netherlands)

    van Zeist, W.-J.; Fonseca Guerra, C.; Bickelhaupt, F.M.

    2008-01-01

    The PyFrag program (released as PyFrag2007.01) is a "wrap-around" for the Amsterdam Density Functional (ADF) package and facilitates the extension of the fragment analysis method implemented in ADF along an entire potential energy surface. The purpose is to make analyses of reaction paths and other

  4. [Which route leads from chronic back pain to depression? A path analysis on direct and indirect effects using the cognitive mediators catastrophizing and helplessness/hopelessness in a general population sample].

    Science.gov (United States)

    Fahland, R A; Kohlmann, T; Hasenbring, M; Feng, Y-S; Schmidt, C O

    2012-12-01

    Chronic pain and depression are highly comorbid; however, the longitudinal link is only partially understood. This study examined direct and indirect effects of chronic back pain on depression using path analysis in a general population sample, focussing on cognitive mediator variables. Analyses are based on 413 participants (aged 18-75 years) in a population-based postal survey on back pain who reported chronic back pain at baseline. Follow-up data were collected after 1 year. Depression was measured with the Center for Epidemiologic Studies Depression Scale (CES-D). Fear-avoidance-beliefs (FABQ), catastrophizing and helplessness/hopelessness (KRSS) were considered as cognitive mediators. Data were analyzed using path analysis. Chronic back pain had no direct effect on depression at follow-up when controlling for cognitive mediators. A mediating effect emerged for helplessness/hopelessness but not for catastrophizing or fear-avoidance beliefs. These results support the cognitive mediation hypothesis which assumes that psychological variables mediate the association between pain and depression. The importance of helplessness/hopelessness is of relevance for the treatment of patients with chronic back pain.

  5. Correlation Coefficient, Path Analysis and Drought Tolerance Indices for Wheat under Deficit Irrigation Conditions and Nitrogen Levels

    Directory of Open Access Journals (Sweden)

    A. R Tavakoli

    2012-07-01

    Full Text Available In order to investigate the indices of drought tolerance, correlation coefficient and path analysis at deficit irrigation and nitrogen experiment, this experiment was conducted as split plot arranged in a randomized complete block design (RCBD with three replications during 2000-2003 for wheat at Maragheh agricultural research station of DARI. The treatments were included four levels of deficit irrigation (Rainfed, 100, 160 and 220mm of water use as main plots and five nitrogen rates (0, 30, 60, 90 and 120 kg.N.ha-1 as sub plots. Grain, straw and biological yield, harvest index, productivity degree, plant height, kernel number per spike, Spike number per square meter and TKW determined from the middle of each plot. There were positive significant correlations due to grain yield with all variables: harvest index (r = 0.969 , Productivity degree (r = 0.952 , straw yield (r = 0.904 , plant height (r = 0.904 , biological yield (r = 0.824 , Spike number per square meter (r = 0.817 , kernel number per spike (r = 0.773 and TKW (r = 0.612 respectively. Results of path analysis showed that increase in grain yield was due to increase spike number per square meter and kernel number per spike respectively. On based of indices of drought tolerance (Tolerance Index, Mean Productivity, Geometric Mean Productivity and Harmonic Mean, treatment of %66full irrigation combined with 90KgN.ha-1 was substantially increased water productivity.

  6. Analysis of Known Linear Distributed Average Consensus Algorithms on Cycles and Paths

    Directory of Open Access Journals (Sweden)

    Jesús Gutiérrez-Gutiérrez

    2018-03-01

    Full Text Available In this paper, we compare six known linear distributed average consensus algorithms on a sensor network in terms of convergence time (and therefore, in terms of the number of transmissions required. The selected network topologies for the analysis (comparison are the cycle and the path. Specifically, in the present paper, we compute closed-form expressions for the convergence time of four known deterministic algorithms and closed-form bounds for the convergence time of two known randomized algorithms on cycles and paths. Moreover, we also compute a closed-form expression for the convergence time of the fastest deterministic algorithm considered on grids.

  7. A Run-Length Encoding Approach for Path Analysis of C. elegans Search Behavior

    Directory of Open Access Journals (Sweden)

    Li Huang

    2016-01-01

    Full Text Available The nematode Caenorhabditis elegans explores the environment using a combination of different movement patterns, which include straight movement, reversal, and turns. We propose to quantify C. elegans movement behavior using a computer vision approach based on run-length encoding of step-length data. In this approach, the path of C. elegans is encoded as a string of characters, where each character represents a path segment of a specific type of movement. With these encoded string data, we perform k-means cluster analysis to distinguish movement behaviors resulting from different genotypes and food availability. We found that shallow and sharp turns are the most critical factors in distinguishing the differences among the movement behaviors. To validate our approach, we examined the movement behavior of tph-1 mutants that lack an enzyme responsible for serotonin biosynthesis. A k-means cluster analysis with the path string-encoded data showed that tph-1 movement behavior on food is similar to that of wild-type animals off food. We suggest that this run-length encoding approach is applicable to trajectory data in animal or human mobility data.

  8. Variability and Character Association in F2 Segregating Population ...

    African Journals Online (AJOL)

    Michael Horsfall

    Department of Genetics and Plant Breeding, 1Department of Horticulture. Bangabandhu Sheikh Mujibur Rahman Agricultural University. Gazipur 1706, Bangladesh. ABSTRACT: The F2 segregating generations of exotic tomato hybrids were studied to measure variability, character association and path coefficient analysis.

  9. Exploring the core factors and its dynamic effects on oil price: An application on path analysis and BVAR-TVP model

    International Nuclear Information System (INIS)

    Chai Jian; Guo, Ju-E.; Meng Lei; Wang Shouyang

    2011-01-01

    As the uncertainty of oil price increases, impacts of the influential factors on oil price vary over time. It is of great importance to explore the core factors and its time-varying influence on oil price. In view of this, based on the PATH-ANALYSIS model, this paper obtains the core factors, builds an oil price system VAR model, which uses demand, supply, price, and inventory as endogenous variables, and China's net imports as well as dollar index as exogenous variables. Then we set up a BVAR-TVP (Time varying parameter) model to analyze dynamic impacts of core factors on oil price. The results show that: (1) oil prices became more sensitive to oil supply changes, and the influence delays became shorter; (2) the impact of oil inventories on oil prices with a time lag of two quarters but has a downward trend; (3) the impact of oil consumption on oil prices with a time lag of two quarters, and this effect is increasingly greater; (4) the US dollar index is always the important factor of oil price and its control power increases gradually, and the financial crisis (occurred in 2008) further strengthens the influence of US dollar. - Highlights: ► We build an oil price VAR model based on the PATH-ANALYSIS results. ► The dynamic effects of core factors on oil price was studied by BVAR-TVP model. ► Oil prices became more sensitive to oil supply changes. ► The effect of oil consumption on oil prices is increasingly greater. ► Financial crisis further strengthens the influence of US dollar on oil price.

  10. Analysis of construction dynamic plan using fuzzy critical path method

    Directory of Open Access Journals (Sweden)

    Kurij Kazimir V.

    2014-01-01

    Full Text Available Critical Path Method (CPM technique has become widely recognized as valuable tool for the planning and scheduling large construction projects. The aim of this paper is to present an analytical method for finding the Critical Path in the precedence network diagram where the duration of each activity is represented by a trapezoidal fuzzy number. This Fuzzy Critical Path Method (FCPM uses a defuzzification formula for trapezoidal fuzzy number and applies it on the total float (slack time for each activity in the fuzzy precedence network to find the critical path. The method presented in this paper is very effective in determining the critical activities and finding the critical paths.

  11. Heuristic methods using grasp, path relinking and variable neighborhood search for the clustered traveling salesman problem

    Directory of Open Access Journals (Sweden)

    Mário Mestria

    2013-08-01

    Full Text Available The Clustered Traveling Salesman Problem (CTSP is a generalization of the Traveling Salesman Problem (TSP in which the set of vertices is partitioned into disjoint clusters and objective is to find a minimum cost Hamiltonian cycle such that the vertices of each cluster are visited contiguously. The CTSP is NP-hard and, in this context, we are proposed heuristic methods for the CTSP using GRASP, Path Relinking and Variable Neighborhood Descent (VND. The heuristic methods were tested using Euclidean instances with up to 2000 vertices and clusters varying between 4 to 150 vertices. The computational tests were performed to compare the performance of the heuristic methods with an exact algorithm using the Parallel CPLEX software. The computational results showed that the hybrid heuristic method using VND outperforms other heuristic methods.

  12. Fast exploration of an optimal path on the multidimensional free energy surface

    Science.gov (United States)

    Chen, Changjun

    2017-01-01

    In a reaction, determination of an optimal path with a high reaction rate (or a low free energy barrier) is important for the study of the reaction mechanism. This is a complicated problem that involves lots of degrees of freedom. For simple models, one can build an initial path in the collective variable space by the interpolation method first and then update the whole path constantly in the optimization. However, such interpolation method could be risky in the high dimensional space for large molecules. On the path, steric clashes between neighboring atoms could cause extremely high energy barriers and thus fail the optimization. Moreover, performing simulations for all the snapshots on the path is also time-consuming. In this paper, we build and optimize the path by a growing method on the free energy surface. The method grows a path from the reactant and extends its length in the collective variable space step by step. The growing direction is determined by both the free energy gradient at the end of the path and the direction vector pointing at the product. With fewer snapshots on the path, this strategy can let the path avoid the high energy states in the growing process and save the precious simulation time at each iteration step. Applications show that the presented method is efficient enough to produce optimal paths on either the two-dimensional or the twelve-dimensional free energy surfaces of different small molecules. PMID:28542475

  13. Conseqüências da multicolinearidade sobre a análise de trilha em canola Multicolinearity consequence on path analysis in canola

    Directory of Open Access Journals (Sweden)

    Jefferson Luís Meirelles Coimbra

    2005-04-01

    limitations. In order to evaluate the degree of association among different characters of agronomic importance with an estimative reliable in biological terms, it is striking to quantify the multicolinearity among the studied variables. In addition, the types of statistical and mathematical models used in determining this linear dependence between classifying or independent variables may or may not be adequate for estimatives of biological parameters evaluated. The present work has as objective to present a critical evaluation on the degree of multicolinearity identified and evaluated on the path analysis performed on parts of a canola experiment. The results allow to postulate that path analysis application on the degree of severe multicolinearity produces results with no biological importance for the plant breeder. However, this limitation can be easily identified and corrected through path analysis with colinearity employing a constant (k on diagonal axis of X’X matrix. The model of analysis with severe multicolinearity, however overestimated the single correlation coefficient values comparatively with the weak multicolinearity. Even so, it may not be necessarily more precise, mainly regarding the evaluation of a restricted number of variables included in the analysis or an overlapping of the explainable variables.

  14. Causal Relationships in the Balanced Scorecard: A Path Analysis Approach

    OpenAIRE

    Yael Perlman

    2013-01-01

    We use path analysis to identify causal relationships between different performance measures in each of the four perspectives defined in the balanced scorecard and examine the influence of time lag on relationships between perspectives. We analyze performance data from a real high-tech company. Our results point to a direct relationship between leading measures in the learning and growth perspective and lagging measures in the financial perspective. Our findings also support the existence of ...

  15. Using variable combination population analysis for variable selection in multivariate calibration.

    Science.gov (United States)

    Yun, Yong-Huan; Wang, Wei-Ting; Deng, Bai-Chuan; Lai, Guang-Bi; Liu, Xin-bo; Ren, Da-Bing; Liang, Yi-Zeng; Fan, Wei; Xu, Qing-Song

    2015-03-03

    Variable (wavelength or feature) selection techniques have become a critical step for the analysis of datasets with high number of variables and relatively few samples. In this study, a novel variable selection strategy, variable combination population analysis (VCPA), was proposed. This strategy consists of two crucial procedures. First, the exponentially decreasing function (EDF), which is the simple and effective principle of 'survival of the fittest' from Darwin's natural evolution theory, is employed to determine the number of variables to keep and continuously shrink the variable space. Second, in each EDF run, binary matrix sampling (BMS) strategy that gives each variable the same chance to be selected and generates different variable combinations, is used to produce a population of subsets to construct a population of sub-models. Then, model population analysis (MPA) is employed to find the variable subsets with the lower root mean squares error of cross validation (RMSECV). The frequency of each variable appearing in the best 10% sub-models is computed. The higher the frequency is, the more important the variable is. The performance of the proposed procedure was investigated using three real NIR datasets. The results indicate that VCPA is a good variable selection strategy when compared with four high performing variable selection methods: genetic algorithm-partial least squares (GA-PLS), Monte Carlo uninformative variable elimination by PLS (MC-UVE-PLS), competitive adaptive reweighted sampling (CARS) and iteratively retains informative variables (IRIV). The MATLAB source code of VCPA is available for academic research on the website: http://www.mathworks.com/matlabcentral/fileexchange/authors/498750. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Preparation and tomographic reconstruction of an arbitrary single-photon path qubit

    International Nuclear Information System (INIS)

    Baek, So-Young; Kim, Yoon-Ho

    2011-01-01

    We report methods for preparation and tomographic reconstruction of an arbitrary single-photon path qubit. The arbitrary single-photon path qubit is prepared losslessly by passing the heralded single-photon state from spontaneous parametric down-conversion through variable beam splitter. Quantum state tomography of the single-photon path qubit is implemented by introducing path-projection measurements based on the first-order single-photon quantum interference. Using the state preparation and path-projection measurements methods for the single-photon path qubit, we demonstrate preparation and complete tomographic reconstruction of the single-photon path qubit with arbitrary purity. -- Highlights: → We report methods for preparation and tomographic reconstruction of an arbitrary single-photon path qubit. → We implement path-projection measurements based on the first-order single-photon quantum interference. → We demonstrate preparation and complete tomographic reconstruction of the single-photon path qubit with arbitrary purity.

  17. Life course path analysis of birth weight, childhood growth, and adult systolic blood pressure

    DEFF Research Database (Denmark)

    Gamborg, Michael; Andersen, Per Kragh; Baker, Jennifer L

    2009-01-01

    body size, and thereby the total effect, of size and changes in size on later outcomes. Using data on childhood body size and adult systolic blood pressure from a sample of 1,284 Danish men born between 1936 and 1970, the authors compared results from path analysis with results from 3 standard...... regression methods. Path analysis produced easily interpretable results, and compared with standard regression methods it produced a noteworthy gain in statistical power. The effect of change in relative body size on adult blood pressure was more pronounced after age 11 years than in earlier childhood....... These results suggest that increases in body size prior to age 11 years are less harmful to adult blood pressure than increases occurring after this age....

  18. Path Analysis Association between Domestic Violence, Anxiety, Depression and Perceived Stress in Mothers and Children's Development.

    Science.gov (United States)

    Vameghi, Roshanak; Amir Ali Akbari, Sedigheh; Sajedi, Firoozeh; Sajjadi, Homeira; Alavi Majd, Hamid

    2016-01-01

    Given that several factors involved in the incidence or exacerbation of developmental disorders in children, the present study aimed to investigate the relationship between some of the risk factors affecting mothers' health and development in children using path analysis. The present cross-sectional analytical study was conducted on 750 mothers and their children in health centers in Tehran, Iran in 2014 enrolled through multi-stage random sampling. Data were collected using a demographic and personal information questionnaire, the Perceived Stress Scale, Beck's depression Inventory, Spielberger' anxiety inventory, the WHO domestic violence questionnaire and an ages & stages questionnaire for assessing children's development. Data were analyzed using SPSS.19 (Chicago, IL, USA) and Lisrel 8.8. Developmental delay was observed in 12.1% of the children. The mean stress score was 23.94±8.62 in the mothers, 50.7% of whom showed mild to severe depression, 84.2% moderate to severe anxiety and 35.3% had been subjected to domestic violence. The path analysis showed that children's development was affected directly by perceived stress (β=-0.09) and depression (β=-0.17) and indirectly by domestic violence (β=-0.05278) and anxiety (β=-0.0357). Of all the variables examined, depression had the biggest influence on development in the children (β=-0.17). The proposed model showed a good fit (GFI=1, RMSEA=0.034). Children's development was influenced indirectly by domestic violence and anxiety and directly by perceived stress and depression in mothers. It is thus suggested that more concern and attention be paid to women's mental health and the domestic violence they experience.

  19. Substructuring of multibody systems for numerical transfer path analysis in internal combustion engines

    Science.gov (United States)

    Acri, Antonio; Offner, Guenter; Nijman, Eugene; Rejlek, Jan

    2016-10-01

    Noise legislations and the increasing customer demands determine the Noise Vibration and Harshness (NVH) development of modern commercial vehicles. In order to meet the stringent legislative requirements for the vehicle noise emission, exact knowledge of all vehicle noise sources and their acoustic behavior is required. Transfer path analysis (TPA) is a fairly well established technique for estimating and ranking individual low-frequency noise or vibration contributions via the different transmission paths. Transmission paths from different sources to target points of interest and their contributions can be analyzed by applying TPA. This technique is applied on test measurements, which can only be available on prototypes, at the end of the designing process. In order to overcome the limits of TPA, a numerical transfer path analysis methodology based on the substructuring of a multibody system is proposed in this paper. Being based on numerical simulation, this methodology can be performed starting from the first steps of the designing process. The main target of the proposed methodology is to get information of noise sources contributions of a dynamic system considering the possibility to have multiple forces contemporary acting on the system. The contributions of these forces are investigated with particular focus on distribute or moving forces. In this paper, the mathematical basics of the proposed methodology and its advantages in comparison with TPA will be discussed. Then, a dynamic system is investigated with a combination of two methods. Being based on the dynamic substructuring (DS) of the investigated model, the methodology proposed requires the evaluation of the contact forces at interfaces, which are computed with a flexible multi-body dynamic (FMBD) simulation. Then, the structure-borne noise paths are computed with the wave based method (WBM). As an example application a 4-cylinder engine is investigated and the proposed methodology is applied on the

  20. Analysis of Crack Propagation Path on the Anisotropic Bi-Material Rock

    Directory of Open Access Journals (Sweden)

    Chao-Shi Chen

    2010-01-01

    Full Text Available This paper presents a single-domain boundary element method (SDBEM for linear elastic fracture mechanics analysis in the 2D anisotropic bimaterial. In this formulation, the displacement integral equation is collocated on the uncracked boundary only, and the traction integral equation is collocated on one side of the crack surface only. The complete fundamental solution (Green's function for anisotropic bi-materials was also derived and implemented into the boundary integral formulation so the discretization along the interface can be avoided except for the interfacial crack part. A special crack-tip element was introduced to capture exactly the crack-tip behavior. A computer program with the FORTRAN code has been developed to effectively calculate the stress intensity factors, crack initiation angle, and propagation path of an anisotropic bi-material. This SDBEM program has been verified having a good accuracy with the previous researches. In addition, a rock of type (1/(2 disk specimen with a central crack was made to conduct the Brazilian test under diametrical loading. The result shows that the numerical analysis can predict relatively well the direction of crack initiation and the path of crack propagation.

  1. Experimental demonstration of spectrum-sliced elastic optical path network (SLICE).

    Science.gov (United States)

    Kozicki, Bartłomiej; Takara, Hidehiko; Tsukishima, Yukio; Yoshimatsu, Toshihide; Yonenaga, Kazushige; Jinno, Masahiko

    2010-10-11

    We describe experimental demonstration of spectrum-sliced elastic optical path network (SLICE) architecture. We employ optical orthogonal frequency-division multiplexing (OFDM) modulation format and bandwidth-variable optical cross-connects (OXC) to generate, transmit and receive optical paths with bandwidths of up to 1 Tb/s. We experimentally demonstrate elastic optical path setup and spectrally-efficient transmission of multiple channels with bit rates ranging from 40 to 140 Gb/s between six nodes of a mesh network. We show dynamic bandwidth scalability for optical paths with bit rates of 40 to 440 Gb/s. Moreover, we demonstrate multihop transmission of a 1 Tb/s optical path over 400 km of standard single-mode fiber (SMF). Finally, we investigate the filtering properties and the required guard band width for spectrally-efficient allocation of optical paths in SLICE.

  2. Path operator algebras in conformal quantum field theories

    International Nuclear Information System (INIS)

    Roesgen, M.

    2000-10-01

    Two different kinds of path algebras and methods from noncommutative geometry are applied to conformal field theory: Fusion rings and modular invariants of extended chiral algebras are analyzed in terms of essential paths which are a path description of intertwiners. As an example, the ADE classification of modular invariants for minimal models is reproduced. The analysis of two-step extensions is included. Path algebras based on a path space interpretation of character identities can be applied to the analysis of fusion rings as well. In particular, factorization properties of character identities and therefore of the corresponding path spaces are - by means of K-theory - related to the factorization of the fusion ring of Virasoro- and W-algebras. Examples from nonsupersymmetric as well as N=2 supersymmetric minimal models are discussed. (orig.)

  3. THE PATH TO JOB SATISFACTION. APPLYING THE THEORY OF PURPOSEFUL BEHAVIOR TO MILITARY CONDITIONS

    Directory of Open Access Journals (Sweden)

    Johan ÖSTERBERG

    2017-04-01

    Full Text Available The aim of this study was to examine the relationships between, on one hand, personality and performance orientation and, on the other, job satisfaction and turnover intentions, using Barrick’s et al. theory of purposeful behavior. Using a questionnaire, data about job satisfaction, performance orientation and turnover intentions were collected from 300 newly recruited Swedish soldiers. A path analysis gave partial, but not full support to the assumptions behind the theory of purposeful behavior model. No relationships were found between the personality traits of emotional stability and conscientiousness, nor to either performance orientation or directly to job satisfaction. On the other hand, performance orientation showed a consistent relationship to perceived levels of the job characteristics, which mediated the path between the person-related variables and the outcome variables. Performance orientation also showed a strong direct relationship to general job satisfaction, which, in turn, was strongly related to turnover intentions.

  4. Influence of social cognitive and ethnic variables on academic goals of underrepresented students in science and engineering: a multiple-groups analysis.

    Science.gov (United States)

    Byars-Winston, Angela; Estrada, Yannine; Howard, Christina; Davis, Dalelia; Zalapa, Juan

    2010-04-01

    This study investigated the academic interests and goals of 223 African American, Latino/a, Southeast Asian, and Native American undergraduate students in two groups: biological science and engineering (S/E) majors. Using social cognitive career theory (Lent, Brown, & Hackett, 1994), we examined the relationships of social cognitive variables (math/science academic self-efficacy, math/science outcome expectations), along with the influence of ethnic variables (ethnic identity, other-group orientation) and perceptions of campus climate to their math/science interests and goal commitment to earn an S/E degree. Path analysis revealed that the hypothesized model provided good overall fit to the data, revealing significant relationships from outcome expectations to interests and to goals. Paths from academic self-efficacy to S/E goals and from interests to S/E goals varied for students in engineering and biological science. For both groups, other-group orientation was positively related to self-efficacy and support was found for an efficacy-mediated relationship between perceived campus climate and goals. Theoretical and practical implications of the study's findings are considered as well as future research directions.

  5. Comparison of classical reaction paths and tunneling paths studied with the semiclassical instanton theory.

    Science.gov (United States)

    Meisner, Jan; Markmeyer, Max N; Bohner, Matthias U; Kästner, Johannes

    2017-08-30

    Atom tunneling in the hydrogen atom transfer reaction of the 2,4,6-tri-tert-butylphenyl radical to 3,5-di-tert-butylneophyl, which has a short but strongly curved reaction path, was investigated using instanton theory. We found the tunneling path to deviate qualitatively from the classical intrinsic reaction coordinate, the steepest-descent path in mass-weighted Cartesian coordinates. To perform that comparison, we implemented a new variant of the predictor-corrector algorithm for the calculation of the intrinsic reaction coordinate. We used the reaction force analysis method as a means to decompose the reaction barrier into structural and electronic components. Due to the narrow energy barrier, atom tunneling is important in the abovementioned reaction, even above room temperature. Our calculated rate constants between 350 K and 100 K agree well with experimental values. We found a H/D kinetic isotope effect of almost 10 6 at 100 K. Tunneling dominates the protium transfer below 400 K and the deuterium transfer below 300 K. We compared the lengths of the tunneling path and the classical path for the hydrogen atom transfer in the reaction HCl + Cl and quantified the corner cutting in this reaction. At low temperature, the tunneling path is about 40% shorter than the classical path.

  6. A Path Model of School Violence Perpetration: Introducing Online Game Addiction as a New Risk Factor.

    Science.gov (United States)

    Kim, Jae Yop; Lee, Jeen Suk; Oh, Sehun

    2015-08-10

    Drawing on the cognitive information-processing model of aggression and the general aggression model, we explored why adolescents become addicted to online games and how their immersion in online games affects school violence perpetration (SVP). For this purpose, we conducted statistical analyses on 1,775 elementary and middle school students who resided in northern districts of Seoul, South Korea. The results validated the proposed structural equation model and confirmed the statistical significance of the structural paths from the variables; that is, the paths from child abuse and self-esteem to SVP were significant. The levels of self-esteem and child abuse victimization affected SVP, and this effect was mediated by online game addiction (OGA). Furthermore, a multigroup path analysis showed significant gender differences in the path coefficients of the proposed model, indicating that gender exerted differential effects on adolescents' OGA and SVP. Based on these results, prevention and intervention methods to curb violence in schools have been proposed. © The Author(s) 2015.

  7. Path coupling and aggregate path coupling

    CERN Document Server

    Kovchegov, Yevgeniy

    2018-01-01

    This book describes and characterizes an extension to the classical path coupling method applied to statistical mechanical models, referred to as aggregate path coupling. In conjunction with large deviations estimates, the aggregate path coupling method is used to prove rapid mixing of Glauber dynamics for a large class of statistical mechanical models, including models that exhibit discontinuous phase transitions which have traditionally been more difficult to analyze rigorously. The book shows how the parameter regions for rapid mixing for several classes of statistical mechanical models are derived using the aggregate path coupling method.

  8. Job Stress and Related Factors Among Iranian Male Staff Using a Path Analysis Model.

    Science.gov (United States)

    Azad-Marzabadi, Esfandiar; Gholami Fesharaki, Mohammad

    2016-06-01

    In recent years, job stress has been cited as a risk factor for some diseases. Given the importance of this subject, we established a new model for classifying job stress among Iranian male staff using path analysis. This cross-sectional study was done on male staff in Tehran, Iran, 2013. The participants in the study were selected using a proportional stratum sampling method. The tools used included nine questionnaires (1- HSE questionnaire; 2- GHQ questionnaire; 3- Beck depression inventory; 4- Framingham personality type; 5- Azad-Fesharaki's physical activity questionnaire; 6- Adult attachment style questionnaire; 7- Azad socioeconomic questionnaire; 8- Job satisfaction survey; and 9- demographic questionnaire). A total of 575 individuals (all male) were recruited for the study. Their mean (±SD) age was 33.49 (±8.9) and their mean job experience was 12.79 (±8.98) years. The pathway of job stress among Iranian male staff showed an adequate model fit (RMSEA=0.021, GFI=0.99, AGFI=0.97, P=0.136). In addition, the total effect of variables like personality type (β=0.283), job satisfaction (β=0.287), and age (β=0.108) showed a positive relationship with job stress, while variables like general health (β=-0.151) and depression (β=-0.242) showed the reverse effect on job stress. According to the results of this study, we can conclude that our suggested model is suited to explaining the pathways of stress among Iranian male staff.

  9. Social Cognitive Career Theory, Conscientiousness, and Work Performance: A Meta-Analytic Path Analysis

    Science.gov (United States)

    Brown, Steven D.; Lent, Robert W.; Telander, Kyle; Tramayne, Selena

    2011-01-01

    We performed a meta-analytic path analysis of an abbreviated version of social cognitive career theory's (SCCT) model of work performance (Lent, Brown, & Hackett, 1994). The model we tested included the central cognitive predictors of performance (ability, self-efficacy, performance goals), with the exception of outcome expectations. Results…

  10. Prairie Network Fireballs: Data of motion and ablation of fireball bodies obtained by local-ballistic method applied to variably-sliding path-segment

    Science.gov (United States)

    Kalenichenko, Valentin V.

    2000-11-01

    The electronic version of an extensive catalogue of the results of the fireball physics inverse problem solution for the precise observational data of the Prairie Network Fireballs (DTHM-values) obtained by local-ballistic method of a variably-sliding path-segment contains a set of the physical parameters for the 480 fireball images of the 248 cosmic body entries into the Earth's atmosphere (PNVK-values). The parameters are: the fireball velocity with the corresponding values of the mass to cross-section area ratio for the fireball-generating body a teach measured point of the fireball path, the ablation factor and the ratio of the luminous fireball energy to the drag work for the body in the Earth's atmosphere using a factor inversely proportional to the density of the body. The catalogue of all PNVK-values, about 3.1 Mbytes in ASCII is accessible from ftp://ftp2.mao.kiev.ua/pub/astro/pnvk, files pnvk.cat and pnvks.cat

  11. Capturing cognitive causal paths in human reliability analysis with Bayesian network models

    International Nuclear Information System (INIS)

    Zwirglmaier, Kilian; Straub, Daniel; Groth, Katrina M.

    2017-01-01

    reIn the last decade, Bayesian networks (BNs) have been identified as a powerful tool for human reliability analysis (HRA), with multiple advantages over traditional HRA methods. In this paper we illustrate how BNs can be used to include additional, qualitative causal paths to provide traceability. The proposed framework provides the foundation to resolve several needs frequently expressed by the HRA community. First, the developed extended BN structure reflects the causal paths found in cognitive psychology literature, thereby addressing the need for causal traceability and strong scientific basis in HRA. Secondly, the use of node reduction algorithms allows the BN to be condensed to a level of detail at which quantification is as straightforward as the techniques used in existing HRA. We illustrate the framework by developing a BN version of the critical data misperceived crew failure mode in the IDHEAS HRA method, which is currently under development at the US NRC . We illustrate how the model could be quantified with a combination of expert-probabilities and information from operator performance databases such as SACADA. This paper lays the foundations necessary to expand the cognitive and quantitative foundations of HRA. - Highlights: • A framework for building traceable BNs for HRA, based on cognitive causal paths. • A qualitative BN structure, directly showing these causal paths is developed. • Node reduction algorithms are used for making the BN structure quantifiable. • BN quantified through expert estimates and observed data (Bayesian updating). • The framework is illustrated for a crew failure mode of IDHEAS.

  12. Distribution definition of path integrals

    International Nuclear Information System (INIS)

    Kerler, W.

    1979-01-01

    By starting from quantum mechanics it turns out that a rather general definition of quantum functional integrals can be given which is based on distribution theory. It applies also to curved space and provides clear rules for non-linear transformations. The refinements necessary in usual definitions of path integrals are pointed out. Since the quantum nature requires special care with time sequences, it is not the classical phase space which occurs in the phase-space form of the path integral. Feynman's configuration-space form only applies to a highly specialized situation, and therefore is not a very advantageous starting point for general investigations. It is shown that the commonly used substitutions of variables do not properly account for quantum effects. The relation to the traditional ordering problem is clarified. The distribution formulation has allowed to treat constrained systems directly at the quantum level, to complete the path integral formulation of the equivalence theorem, and to define functional integrals also for space translation after the transition to fields. (orig.)

  13. Path Creation, Path Dependence and Breaking Away from the Path

    OpenAIRE

    Wang, Jens; Hedman, Jonas; Tuunainen, Virpi Kristiina

    2016-01-01

    The explanation of how and why firms succeed or fail is a recurrent research challenge. This is particularly important in the context of technological innovations. We focus on the role of historical events and decisions in explaining such success and failure. Using a case study of Nokia, we develop and extend a multi-layer path dependence framework. We identify four layers of path dependence: technical, strategic and leadership, organizational, and external collaboration. We show how path dep...

  14. Computer-Aided Modelling of Short-Path Evaporation for Chemical Product Purification, Analysis and Design

    DEFF Research Database (Denmark)

    Sales-Cruz, Alfonso Mauricio; Gani, Rafiqul

    2006-01-01

    method, suitable for separation and purification of thermally unstable materials whose design and analysis can be efficiently performed through reliable model-based techniques. This paper presents a generalized model for short-path evaporation and highlights its development, implementation and solution...

  15. Routeing of power lines through least-cost path analysis and multicriteria evaluation to minimise environmental impacts

    International Nuclear Information System (INIS)

    Bagli, Stefano; Geneletti, Davide; Orsi, Francesco

    2011-01-01

    Least-cost path analysis (LCPA) allows designers to find the 'cheapest' way to connect two locations within a cost surface, which can be computed by combining multiple criteria, and therefore by accounting for different issues (environmental impact, economic investment, etc.). This procedure can be easily implemented with modern Geographic Information System (GIS) technologies, and consequently it has been widely employed to support planning and design of different types of linear infrastructures, ranging from roads to pipelines. This paper presents an approach based on the integration of multicriteria evaluation (MCE) and LCPA to identify the most suitable route for a 132 kV power line. Criteria such as cost, visibility, population density, and ecosystem naturalness were used for the analysis. Firstly, spatial MCE and LCPA were combined to generate cost surfaces, and to identify alternative paths. Subsequently, MCE was used to compare the alternatives, and rank them according to their overall suitability. Finally, a sensitivity analysis allowed the stability of the results to be tested and the most critical factors of the evaluation to be detected. The study found that small changes in the location of the power line start and end points can result in significantly different paths, and consequently impact levels. This suggested that planners should always consider alternative potential locations of terminals in order to identify the best path. Furthermore, it was shown that the use of different weight scenarios may help making the model adaptable to varying environmental and social contexts. The approach was tested on a real-world case study in north-eastern Italy.

  16. An open-chain imaginary-time path-integral sampling approach to the calculation of approximate symmetrized quantum time correlation functions

    Science.gov (United States)

    Cendagorta, Joseph R.; Bačić, Zlatko; Tuckerman, Mark E.

    2018-03-01

    We introduce a scheme for approximating quantum time correlation functions numerically within the Feynman path integral formulation. Starting with the symmetrized version of the correlation function expressed as a discretized path integral, we introduce a change of integration variables often used in the derivation of trajectory-based semiclassical methods. In particular, we transform to sum and difference variables between forward and backward complex-time propagation paths. Once the transformation is performed, the potential energy is expanded in powers of the difference variables, which allows us to perform the integrals over these variables analytically. The manner in which this procedure is carried out results in an open-chain path integral (in the remaining sum variables) with a modified potential that is evaluated using imaginary-time path-integral sampling rather than requiring the generation of a large ensemble of trajectories. Consequently, any number of path integral sampling schemes can be employed to compute the remaining path integral, including Monte Carlo, path-integral molecular dynamics, or enhanced path-integral molecular dynamics. We believe that this approach constitutes a different perspective in semiclassical-type approximations to quantum time correlation functions. Importantly, we argue that our approximation can be systematically improved within a cumulant expansion formalism. We test this approximation on a set of one-dimensional problems that are commonly used to benchmark approximate quantum dynamical schemes. We show that the method is at least as accurate as the popular ring-polymer molecular dynamics technique and linearized semiclassical initial value representation for correlation functions of linear operators in most of these examples and improves the accuracy of correlation functions of nonlinear operators.

  17. An open-chain imaginary-time path-integral sampling approach to the calculation of approximate symmetrized quantum time correlation functions.

    Science.gov (United States)

    Cendagorta, Joseph R; Bačić, Zlatko; Tuckerman, Mark E

    2018-03-14

    We introduce a scheme for approximating quantum time correlation functions numerically within the Feynman path integral formulation. Starting with the symmetrized version of the correlation function expressed as a discretized path integral, we introduce a change of integration variables often used in the derivation of trajectory-based semiclassical methods. In particular, we transform to sum and difference variables between forward and backward complex-time propagation paths. Once the transformation is performed, the potential energy is expanded in powers of the difference variables, which allows us to perform the integrals over these variables analytically. The manner in which this procedure is carried out results in an open-chain path integral (in the remaining sum variables) with a modified potential that is evaluated using imaginary-time path-integral sampling rather than requiring the generation of a large ensemble of trajectories. Consequently, any number of path integral sampling schemes can be employed to compute the remaining path integral, including Monte Carlo, path-integral molecular dynamics, or enhanced path-integral molecular dynamics. We believe that this approach constitutes a different perspective in semiclassical-type approximations to quantum time correlation functions. Importantly, we argue that our approximation can be systematically improved within a cumulant expansion formalism. We test this approximation on a set of one-dimensional problems that are commonly used to benchmark approximate quantum dynamical schemes. We show that the method is at least as accurate as the popular ring-polymer molecular dynamics technique and linearized semiclassical initial value representation for correlation functions of linear operators in most of these examples and improves the accuracy of correlation functions of nonlinear operators.

  18. Definition of mean free path for real gases

    Science.gov (United States)

    Bird, G. A.

    1983-11-01

    Attention is drawn to the inconsistency in the conventional procedure for the definition of a mean free path in a real gas through the classical hard sphere result. It is shown that the variable cross-section hard sphere, or VHS, model can be used to define a mean free path that properly accounts for the temperature exponent of the coefficient of viscosity of the gas. In addition, the VHS model is shown to have advantages over the classical inverse power law models for numerical and analytical studies.

  19. The effect analysis of mediation variable of task productivity on the self-efficacy and employees’ performance

    Directory of Open Access Journals (Sweden)

    Annissa Chairum Soebandono

    2016-11-01

    Full Text Available This research was conducted for analyzing the effect of mediating variable that is individual task proactivity as one of the proactivities of behavior towards the relationship between self-efficacy and the employees’ performance in the logistics companies of shipping the goods. It uses convenience sampling, which is a non-probability sampling method for getting the sample of 52 employees. They were divided into two divisions, namely infrastructure and quality assurance. The questionnaire consists of two parts, in which some were assessed by themselves and others that were assessed by the supervisor. They were analyzed using path analysis using analytical tools developed by Hayes, Preacher-Hayes with the simple mediation models. It was found that employees have self-efficacy, individual task proactivity, and relatively high performance, in which individual task proactivity can be a mediating variable on the effect self-efficacy on performance.

  20. Bifurcation of rupture path by linear and cubic damping force

    Science.gov (United States)

    Dennis L. C., C.; Chew X., Y.; Lee Y., C.

    2014-06-01

    Bifurcation of rupture path is studied for the effect of linear and cubic damping. Momentum equation with Rayleigh factor was transformed into ordinary differential form. Bernoulli differential equation was obtained and solved by the separation of variables. Analytical or exact solutions yielded the bifurcation was visible at imaginary part when the wave was non dispersive. For the dispersive wave, bifurcation of rupture path was invisible.

  1. Associations among health behaviors, body mass index, hypertension, and diabetes mellitus: A path analysis.

    Science.gov (United States)

    Min, Deulle; Cho, Eunhee

    2018-06-01

    Hypertension (HTN) and type 2 diabetes are common diseases; however, the effects of health behavior and body mass index (BMI) on their incidence and relationship are unclear. The purpose of this study was to investigate the associations among health behaviors, BMI, HTN, and type 2 diabetes.This study was a secondary data analysis using Korean Longitudinal Study of Aging data between 2010 and 2014 (third and fifth). The sample consisted of 3481 people aged 45 years or older. Path analysis was conducted using the generalized structural equation modeling of STATA 13.1 that enabled analyzing the types of binary variables and logit links.There were 129 underweight, 1714 normal, and 1638 overweight and obese individuals. In underweight and normal groups who had regular meals (B = 0.670, P diabetes increased with age (B = 0.051, P = .005) and smoking (B = 1.539, P = .001). However, the incidence of type 2 diabetes was lower (B = -1.077, P = .036) for those who had regular meals. In the normal and overweight groups, BMI decreased with age (B = -0.033, P diabetes increased with age (B = 0.046, P diabetes. Smoking has a direct effect on the incidence of type 2 diabetes. Thus, the importance of maintaining an ideal BMI and smoking cessation are highlighted.

  2. On load paths and load bearing topology from finite element analysis

    International Nuclear Information System (INIS)

    Kelly, D; Reidsema, C; Lee, M

    2010-01-01

    Load paths can be mapped from vector plots of 'pointing stress vectors'. They define a path along which a component of load remains constant as it traverses the solution domain. In this paper the theory for the paths is first defined. Properties of the plots that enable a designer to interpret the structural behavior from the contours are then identified. Because stress is a second order tensor defined on an orthogonal set of axes, the vector plots define separate paths for load transfer in each direction of the set of axes. An algorithm is therefore presented that combines the vectors to define a topology to carry the loads. The algorithm is shown to straighten the paths reducing bending moments and removing stress concentration. Application to a bolted joint, a racing car body and a yacht hull demonstrate the usefulness of the plots.

  3. Equilibrium paths analysis of materials with rheological properties by using the chaos theory

    Science.gov (United States)

    Bednarek, Paweł; Rządkowski, Jan

    2018-01-01

    The numerical equilibrium path analysis of the material with random rheological properties by using standard procedures and specialist computer programs was not successful. The proper solution for the analysed heuristic model of the material was obtained on the base of chaos theory elements and neural networks. The paper deals with mathematical reasons of used computer programs and also are elaborated the properties of the attractor used in analysis. There are presented results of conducted numerical analysis both in a numerical and in graphical form for the used procedures.

  4. Relationships between the quality of blended learning experience, self-regulated learning, and academic achievement of medical students: a path analysis.

    Science.gov (United States)

    Kassab, Salah Eldin; Al-Shafei, Ahmad I; Salem, Abdel Halim; Otoom, Sameer

    2015-01-01

    This study examined the relationships between the different aspects of students' course experience, self-regulated learning, and academic achievement of medical students in a blended learning curriculum. Perceptions of medical students (n=171) from the Royal College of Surgeons in Ireland, Medical University of Bahrain (RCSI Bahrain), on the blended learning experience were measured using the Student Course Experience Questionnaire (SCEQ), with an added e-Learning scale. In addition, self-regulated learning was measured using the Motivated Strategies for Learning Questionnaire (MSLQ). Academic achievement was measured by the scores of the students at the end of the course. A path analysis was created to test the relationships between the different study variables. Path analysis indicated that the perceived quality of the face-to-face component of the blended experience directly affected the motivation of students. The SCEQ scale "quality of teaching" directly affected two aspects of motivation: control of learning and intrinsic goal orientation. Furthermore, appropriate course workload directly affected the self-efficacy of students. Moreover, the e-Learning scale directly affected students' peer learning and critical thinking but indirectly affected metacognitive regulation. The resource management regulation strategies, time and study environment, and effort regulation directly affected students' examination scores (17% of the variance explained). However, there were no significant direct relationships between the SCEQ scales and cognitive learning strategies or examination scores. The results of this study will have important implications for designing blended learning courses in medical schools.

  5. Microscopic optical path length difference and polarization measurement system for cell analysis

    Science.gov (United States)

    Satake, H.; Ikeda, K.; Kowa, H.; Hoshiba, T.; Watanabe, E.

    2018-03-01

    In recent years, noninvasive, nonstaining, and nondestructive quantitative cell measurement techniques have become increasingly important in the medical field. These cell measurement techniques enable the quantitative analysis of living cells, and are therefore applied to various cell identification processes, such as those determining the passage number limit during cell culturing in regenerative medicine. To enable cell measurement, we developed a quantitative microscopic phase imaging system based on a Mach-Zehnder interferometer that measures the optical path length difference distribution without phase unwrapping using optical phase locking. The applicability of our phase imaging system was demonstrated by successful identification of breast cancer cells amongst normal cells. However, the cell identification method using this phase imaging system exhibited a false identification rate of approximately 7%. In this study, we implemented a polarimetric imaging system by introducing a polarimetric module to one arm of the Mach-Zehnder interferometer of our conventional phase imaging system. This module was comprised of a quarter wave plate and a rotational polarizer on the illumination side of the sample, and a linear polarizer on the optical detector side. In addition, we developed correction methods for the measurement errors of the optical path length and birefringence phase differences that arose through the influence of elements other than cells, such as the Petri dish. As the Petri dish holding the fluid specimens was transparent, it did not affect the amplitude information; however, the optical path length and birefringence phase differences were affected. Therefore, we proposed correction of the optical path length and birefringence phase for the influence of elements other than cells, as a prerequisite for obtaining highly precise phase and polarimetric images.

  6. Mathematics Teaching Anxiety and Self-Efficacy Beliefs toward Mathematics Teaching: A Path Analysis

    Science.gov (United States)

    Peker, Murat

    2016-01-01

    The purpose of this study was to investigate the relationship between pre-service primary school teachers' mathematics teaching anxiety and their self-efficacy beliefs toward mathematics teaching through path analysis. There were a total of 250 pre-service primary school teachers involved in this study. Of the total, 202 were female and 48 were…

  7. Prediction of crack paths in WC-Co alloys

    International Nuclear Information System (INIS)

    Spiegler, R.; Fischmeister, H.F.

    1992-01-01

    This paper reports on a crack propagating through the WC-o microstructure which has to choose between paths along the binder/carbide interface and paths across binder regions. The latter paths are selected when the crack enters a binder region at a large angle from the nearest carbide interface, while the interface paths are preferred by cracks entering at a small angle. A critical angle can be defined for the switch from one type of crack path to the other. Empirical data for the area fractions of the two crack paths in widely different WC-Co alloys can be accounted for by a single critical angle, var-phi c = 25 degrees. Finite element analysis of the stress field in a region of binder enclosed between carbide grains shows that the preferred site for the growth of stress-induced microvoids will move from the carbide grain flanks to the interior of the binder region when the entry angle of the crack exceeds 24 degrees. Thus the observation of a critical angle deciding the crack path is verified by the stress field analysis and given a physical explanation in terms of the most likely site for microvoid formation

  8. Walking paths to and from a goal differ: on the role of bearing angle in the formation of human locomotion paths.

    Directory of Open Access Journals (Sweden)

    Manish Sreenivasa

    Full Text Available The path that humans take while walking to a goal is the result of a cognitive process modulated by the perception of the environment and physiological constraints. The path shape and timing implicitly embeds aspects of the architecture behind this process. Here, locomotion paths were investigated during a simple task of walking to and from a goal, by looking at the evolution of the position of the human on a horizontal (x,y plane. We found that the path while walking to a goal was not the same as that while returning from it. Forward-return paths were systematically separated by 0.5-1.9m, or about 5% of the goal distance. We show that this path separation occurs as a consequence of anticipating the desired body orientation at the goal while keeping the target in view. The magnitude of this separation was strongly influenced by the bearing angle (difference between body orientation and angle to goal and the final orientation imposed at the goal. This phenomenon highlights the impact of a trade-off between a directional perceptual apparatus-eyes in the head on the shoulders-and and physiological limitations, in the formation of human locomotion paths. Our results give an insight into the influence of environmental and perceptual variables on human locomotion and provide a basis for further mathematical study of these mechanisms.

  9. Projects Delay Factors of Saudi Arabia Construction Industry Using PLS-SEM Path Modelling Approach

    Directory of Open Access Journals (Sweden)

    Abdul Rahman Ismail

    2016-01-01

    Full Text Available This paper presents the development of PLS-SEM Path Model of delay factors of Saudi Arabia construction industry focussing on Mecca City. The model was developed and assessed using SmartPLS v3.0 software and it consists of 37 factors/manifests in 7 groups/independent variables and one dependent variable which is delay of the construction projects. The model was rigorously assessed at measurement and structural components and the outcomes found that the model has achieved the required threshold values. At structural level of the model, among the seven groups, the client and consultant group has the highest impact on construction delay with path coefficient β-value of 0.452 and the project management and contract administration group is having the least impact to the construction delay with β-value of 0.016. The overall model has moderate explaining power ability with R2 value of 0.197 for Saudi Arabia construction industry representation. This model will able to assist practitioners in Mecca city to pay more attention in risk analysis for potential construction delay.

  10. Design and performance analysis of global path planning techniques for autonomous mobile robots in grid environments

    Directory of Open Access Journals (Sweden)

    Imen Chaari

    2017-03-01

    Full Text Available This article presents the results of the 2-year iroboapp research project that aims at devising path planning algorithms for large grid maps with much faster execution times while tolerating very small slacks with respect to the optimal path. We investigated both exact and heuristic methods. We contributed with the design, analysis, evaluation, implementation and experimentation of several algorithms for grid map path planning for both exact and heuristic methods. We also designed an innovative algorithm called relaxed A-star that has linear complexity with relaxed constraints, which provides near-optimal solutions with an extremely reduced execution time as compared to A-star. We evaluated the performance of the different algorithms and concluded that relaxed A-star is the best path planner as it provides a good trade-off among all the metrics, but we noticed that heuristic methods have good features that can be exploited to improve the solution of the relaxed exact method. This led us to design new hybrid algorithms that combine our relaxed A-star with heuristic methods which improve the solution quality of relaxed A-star at the cost of slightly higher execution time, while remaining much faster than A* for large-scale problems. Finally, we demonstrate how to integrate the relaxed A-star algorithm in the robot operating system as a global path planner and show that it outperforms its default path planner with an execution time 38% faster on average.

  11. Path Integration Applied to Structural Systems with Uncertain Properties

    DEFF Research Database (Denmark)

    Nielsen, Søren R.K.; Köylüoglu, H. Ugur

    Path integration (cell-to-cell mapping) method is applied to evaluate the joint probability density function (jpdf) of the response of the structural systems, with uncertain properties, subject to white noise excitation. A general methodology to deal with uncertainties is outlined and applied...... to the friction controlled slip of a structure on a foundation where the friction coefficient is modelled as a random variable. Exact results derived using the total probability theorem are compared to the ones obtained via path integration....

  12. Path Dependency

    OpenAIRE

    Mark Setterfield

    2015-01-01

    Path dependency is defined, and three different specific concepts of path dependency – cumulative causation, lock in, and hysteresis – are analyzed. The relationships between path dependency and equilibrium, and path dependency and fundamental uncertainty are also discussed. Finally, a typology of dynamical systems is developed to clarify these relationships.

  13. Analysis of critical paths for schedule control of nuclear power projects

    International Nuclear Information System (INIS)

    Shi Liangmin; Ma Limin; Fan Kai

    2005-01-01

    Study on the critical paths for the schedule control of nuclear power projects has been performed for reactor M310, based on the experiences from Daya Bay project and Ling Ao project. The study shows that the critical paths for the nuclear power project are from NI civil work, NI erection, commissioning of single systems directly serving the CFT to the joint-test. For NI civil work, the critical path is the main civil work of the reactor building, pre-stressing, handover of rooms for important areas, and key CW-erection interfaces; there are four critical paths for NI erection; For startup, two stages can be identified: commissioning of 16 single systems directly serving the CFT and joint-test. (authors)

  14. Morphological Awareness in Literacy Acquisition of Chinese Second Graders: A Path Analysis.

    Science.gov (United States)

    Zhang, Haomin

    2016-02-01

    The present study tested a path diagram regarding the contribution of morphological awareness (MA) to early literacy acquisition among Chinese-speaking second graders ([Formula: see text]). Three facets of MA were addressed, namely derivational awareness, compound awareness and compound structure awareness. The model aimed to test a theory of causal order among measures of MA and literacy outcomes. Drawing upon multivariate path analysis, direct and indirect effects of MA were analyzed to identify their role in literacy performance among young children. Results revealed that all three facets of MA made significant contributions to lexical inference ability. In addition, compound awareness showed a unique and significant contribution to vocabulary knowledge. It was also observed that lexical inference ability had a mediating effect predictive of both vocabulary knowledge and reading comprehension. Moreover, vocabulary knowledge mediated the effect of MA on reading comprehension. However, no significant contribution of MA to reading comprehension was found after controlling for lexical inference ability and vocabulary knowledge.

  15. Application of path analysis to urinary findings of cadmium-induced renal dysfunction.

    Science.gov (United States)

    Abe, T; Kobayashi, E; Okubo, Y; Suwazono, Y; Kido, T; Shaikh, Z A; Nogawa, K

    2001-01-01

    In order to identify some causal relations among various urinary indices of cadmium-induced renal dysfunction, such as glucose, total protein, amino nitrogen, beta 2-microglobulin (beta 2-m), metallothionein (MT), and cadmium (Cd), we applied path analysis method to previous epidemiological studies targeting the residents of the Cd-polluted Kakehashi River basin of Ishikawa Prefecture, Japan. We obtained a diagram-termed path model, representing some causal relations among the above urinary indices. It shows that urinary Cd is located at the beginning point in the diagram, and Cd-induced renal dysfunction develops in the following order: Cd exposure-->increase of beta 2-m and/or MT excretion-->increase of amino-N and/or total protein excretion-->increase of glucose excretion. It was proved mathematically, that in the case of both males and females, increased excretions of beta 2-m and/or MT were the most sensitive urinary indices of the early stage of chronic Cd-induced renal dysfunction.

  16. Correlation, path analysis and heritability estimation for agronomic traits contribute to yield on soybean

    Science.gov (United States)

    Sulistyo, A.; Purwantoro; Sari, K. P.

    2018-01-01

    Selection is a routine activity in plant breeding programs that must be done by plant breeders in obtaining superior plant genotypes. The use of appropriate selection criteria will determine the effectiveness of selection activities. The purpose of this study was to analysis the inheritable agronomic traits that contribute to soybean yield. A total of 91 soybean lines were planted in Muneng Experimental Station, Probolinggo District, East Java Province, Indonesia in 2016. All soybean lines were arranged in randomized complete block design with two replicates. Correlation analysis, path analysis and heritability estimation were performed on days to flowering, days to maturing, plant height, number of branches, number of fertile nodes, number of filled pods, weight of 100 seeds, and yield to determine selection criteria on soybean breeding program. The results showed that the heritability value of almost all agronomic traits observed is high except for the number of fertile nodes with low heritability. The result of correlation analysis shows that days to flowering, plant height and number of fertile nodes have positive correlation with seed yield per plot (0.056, 0.444, and 0.100, respectively). In addition, path analysis showed that plant height and number of fertile nodes have highest positive direct effect on soybean yield. Based on this result, plant height can be selected as one of selection criteria in soybean breeding program to obtain high yielding soybean variety.

  17. Identification of the excitation source of the pressure vessel vibration in a Soviet built WWER PWR with signal transmission path analysis

    International Nuclear Information System (INIS)

    Antonopoulos-Domis, M.; Mourtzanos, K.; Por, G.

    1996-01-01

    Signal transmission path analysis via multivariate auto-regressive modelling was applied at signals recorded at a WWER power reactor (Paks reactor, Hungary). The core is equipped with strings of self-powered neutron detectors (SPNDs). Each string has seven SPNDs. The signals were high pass filtered with cut-off at 0.03 Hz and low pass-filtered with cut-off at 25 Hz. The analysis suggests that the source of excitation of all signals at 25 Hz is due to main coolant pump vibration. It was confirmed that there is vibration of main coolant pumps at this frequency due to a bearing problem. Signal transmission path analysis also suggests direct paths from outlet coolant to inlet coolant pressure and in-core neutron detectors at the upper part of the core. (author)

  18. Quivers of Bound Path Algebras and Bound Path Coalgebras

    Directory of Open Access Journals (Sweden)

    Dr. Intan Muchtadi

    2010-09-01

    Full Text Available bras and coalgebras can be represented as quiver (directed graph, and from quiver we can construct algebras and coalgebras called path algebras and path coalgebras. In this paper we show that the quiver of a bound path coalgebra (resp. algebra is the dual quiver of its bound path algebra (resp. coalgebra.

  19. The Effects of Land-Use Patterns on Home-Based Tour Complexity and Total Distances Traveled: A Path Analysis

    Directory of Open Access Journals (Sweden)

    João de Abreu e Silva

    2018-03-01

    Full Text Available This work studies the relationships between the number of complex tours (with one or more intermediate stops and simple home-based tours, total distances traveled by mode, and land-use patterns both at the residence and at the workplace using path analysis. The model includes commuting distance, car ownership and motorcycle ownership, which are intermediate variables in the relationship between land use, tour complexity and distances traveled by mode. The dataset used here was collected in a region comprising four municipalities located in the north of Portugal that are made up of urban areas, their sprawling suburbs, and surrounding rural hinterland. The results confirm the association between complex tours and higher levels of car use. Land-use patterns significantly affect travelled distances by mode either directly and indirectly via the influence of longer-term decisions like vehicle ownership and commuting distance. The results obtained highlight the role of socioeconomic variables in influencing tour complexity; in particular, households with children, household income, and workers with a college degree tend to do more complex tours. Land-use patterns mediate the effects of tour complexity on the kilometers travelled by different modes. Increasing densities in central areas, and particularly the concentration of jobs, have relevant benefits by reducing car kilometers driven.

  20. Path integral measure for gravitational interactions

    Directory of Open Access Journals (Sweden)

    Kazuo Fujikawa

    1983-10-01

    Full Text Available It is pointed out that the path-integral variables as well as the local measure for gravitational interactions are uniquely specified if one imposes the anomaly-free condition on the Becchi-Rouet-Stora supersymmetry associated with general coordinate transformations. This prescription is briefly illustrated for the Einstein gravity and supergravity in four space-time dimensions and the relativistic string theory in two dimensions.

  1. The evaluation of a virtual education system based on the DeLone and McLean model:  A path analysis [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Zohreh Mahmoodi

    2017-09-01

    Full Text Available Background: The Internet has dramatically influenced the introduction of virtual education. Virtual education is a term that involves online education and e-learning. This study was conducted to evaluate a virtual education system based on the DeLone and McLean model. Methods: This descriptive analytical study was conducted using the census method on all the students of the Nursing and Midwifery Department of Alborz University of Medical Sciences who had taken at least one online course in 2016-2017. Data were collected using a researcher-made questionnaire based on the DeLone and McLean model in six domains and then analyzed in SPSS-16 and LISREL-8.8 using the path analysis. Results: The goodness of fit indices (GFI of the model represent the desirability and good fit of the model, and the rational nature of the adjusted relationships between the variables based on a conceptual model (GFI = 0.98; RMSEA = 0.014.The results showed that system quality has the greatest impact on the net benefits of the system through both direct and indirect paths (β=0.52, service quality through the indirect path (β=0.03 and user satisfaction through the direct path (β=0.73. Conclusions: According to the results, system quality has the greatest overall impact on the net benefits of the system, both directly and indirectly by affecting user satisfaction and the intention to use. System quality should therefore be further emphasized, to use these systems more efficiently.

  2. The evaluation of a virtual education system based on the DeLone and McLean model:  A path analysis [version 2; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Zohreh Mahmoodi

    2017-09-01

    Full Text Available Background: The Internet has dramatically influenced the introduction of virtual education. Virtual education is a term that involves online education and e-learning. This study was conducted to evaluate a virtual education system based on the DeLone and McLean model. Methods: This descriptive analytical study was conducted using the census method on all the students of the Nursing and Midwifery Department of Alborz University of Medical Sciences who had taken at least one online course in 2016-2017. Data were collected using a researcher-made questionnaire based on the DeLone and McLean model in six domains and then analyzed in SPSS-16 and LISREL-8.8 using the path analysis. Results: The goodness of fit indices (GFI of the model represent the desirability and good fit of the model, and the rational nature of the adjusted relationships between the variables based on a conceptual model (GFI = 0.98; RMSEA = 0.014.The results showed that system quality has the greatest impact on the net benefits of the system through both direct and indirect paths (β=0.52, service quality through the indirect path (β=0.03 and user satisfaction through the direct path (β=0.73. Conclusions: According to the results, system quality has the greatest overall impact on the net benefits of the system, both directly and indirectly by affecting user satisfaction and the intention to use. System quality should therefore be further emphasized, to use these systems more efficiently.

  3. The shortest-path problem analysis and comparison of methods

    CERN Document Server

    Ortega-Arranz, Hector; Gonzalez-Escribano, Arturo

    2014-01-01

    Many applications in different domains need to calculate the shortest-path between two points in a graph. In this paper we describe this shortest path problem in detail, starting with the classic Dijkstra's algorithm and moving to more advanced solutions that are currently applied to road network routing, including the use of heuristics and precomputation techniques. Since several of these improvements involve subtle changes to the search space, it may be difficult to appreciate their benefits in terms of time or space requirements. To make methods more comprehensive and to facilitate their co

  4. Path integrals in curvilinear coordinates

    International Nuclear Information System (INIS)

    Prokhorov, L.V.

    1984-01-01

    Integration limits are studied for presenting the path integral curvilinear coordinates. For spherical (and topoloqically equivalent) coordinates it is shown that in formulas involving classical action in the exponent integration over all variables should be carried out within infinite limits. Another peculiarity is associated with appearance of the operator q which provides a complete definition of the wave functions out of the physical region. arguments are given upporting the validity of the cited statament in the general case

  5. Long open-path measurements of greenhouse gases in air using near-infrared Fourier transform spectroscopy

    Science.gov (United States)

    Griffith, David W. T.; Pöhler, Denis; Schmitt, Stefan; Hammer, Samuel; Vardag, Sanam N.; Platt, Ulrich

    2018-03-01

    In complex and urban environments, atmospheric trace gas composition is highly variable in time and space. Point measurement techniques for trace gases with in situ instruments are well established and accurate, but do not provide spatial averaging to compare against developing high-resolution atmospheric models of composition and meteorology with resolutions of the order of a kilometre. Open-path measurement techniques provide path average concentrations and spatial averaging which, if sufficiently accurate, may be better suited to assessment and interpretation with such models. Open-path Fourier transform spectroscopy (FTS) in the mid-infrared region, and differential optical absorption spectroscopy (DOAS) in the UV and visible, have been used for many years for open-path spectroscopic measurements of selected species in both clean air and in polluted environments. Near infrared instrumentation allows measurements over longer paths than mid-infrared FTS for species such as greenhouse gases which are not easily accessible to DOAS.In this pilot study we present the first open-path near-infrared (4000-10 000 cm-1, 1.0-2.5 µm) FTS measurements of CO2, CH4, O2, H2O and HDO over a 1.5 km path in urban Heidelberg, Germany. We describe the construction of the open-path FTS system, the analysis of the collected spectra, several measures of precision and accuracy of the measurements, and the results a four-month trial measurement period in July-November 2014. The open-path measurements are compared to calibrated in situ measurements made at one end of the open path. We observe significant differences of the order of a few ppm for CO2 and a few tens of ppb for CH4 between the open-path and point measurements which are 2 to 4 times the measurement repeatability, but we cannot unequivocally assign the differences to specific local sources or sinks. We conclude that open-path FTS may provide a valuable new tool for investigations of atmospheric trace gas composition in

  6. REML/BLUP and sequential path analysis in estimating genotypic values and interrelationships among simple maize grain yield-related traits.

    Science.gov (United States)

    Olivoto, T; Nardino, M; Carvalho, I R; Follmann, D N; Ferrari, M; Szareski, V J; de Pelegrin, A J; de Souza, V Q

    2017-03-22

    Methodologies using restricted maximum likelihood/best linear unbiased prediction (REML/BLUP) in combination with sequential path analysis in maize are still limited in the literature. Therefore, the aims of this study were: i) to use REML/BLUP-based procedures in order to estimate variance components, genetic parameters, and genotypic values of simple maize hybrids, and ii) to fit stepwise regressions considering genotypic values to form a path diagram with multi-order predictors and minimum multicollinearity that explains the relationships of cause and effect among grain yield-related traits. Fifteen commercial simple maize hybrids were evaluated in multi-environment trials in a randomized complete block design with four replications. The environmental variance (78.80%) and genotype-vs-environment variance (20.83%) accounted for more than 99% of the phenotypic variance of grain yield, which difficult the direct selection of breeders for this trait. The sequential path analysis model allowed the selection of traits with high explanatory power and minimum multicollinearity, resulting in models with elevated fit (R 2 > 0.9 and ε analysis is effective in the evaluation of maize-breeding trials.

  7. Transition Analysis and Its Application to Global Path Determination for a Biped Climbing Robot

    Directory of Open Access Journals (Sweden)

    Haifei Zhu

    2018-01-01

    Full Text Available Biped climbing robots are considered good assistants and (or substitutes for human workers carrying out high-rise truss-associated routine tasks. Flexible locomotion on three-dimensional complex trusses is a fundamental skill for these robots. In particular, the capability to transit from one structural member to another is paramount for switching objects to be climbed upon. In this paper, we study member-to-member transition and its utility in global path searching for biped climbing robots. To compute operational regions for transition, hierarchical inspection of safety, reachability, and accessibility of grips is taken into account. A novel global path rapid determination approach is subsequently proposed based on the transition analysis. This scheme is efficient for finding feasible routes with respect to the overall structural environment, which also benefits the subsequent grip and motion planning. Simulations are conducted with Climbot, our self-developed biped climbing robot, to verify the efficiency of the presented method. Results show that our proposed method is able to accurately determine the operational region for transition within tens of milliseconds and can obtain global paths within seconds in general.

  8. Path integral for a relativistic-particle theory

    International Nuclear Information System (INIS)

    Fradkin, E.S.; Gitman, D.M.; Shvartsman, S.M.

    1991-01-01

    An action of a relativistic spinning particle written in reparametrization and local super-invariant form is consistently determined by using the path integral representation for the Green's function of the spinor field. It is shown that, to obtain the causal propagator, the integration over the null mode of the onebein variable must be performed in the (0, + ∞ limits

  9. Harmonic and complex analysis in several variables

    CERN Document Server

    Krantz, Steven G

    2017-01-01

    Authored by a ranking authority in harmonic analysis of several complex variables, this book embodies a state-of-the-art entrée at the intersection of two important fields of research: complex analysis and harmonic analysis. Written with the graduate student in mind, it is assumed that the reader has familiarity with the basics of complex analysis of one and several complex variables as well as with real and functional analysis. The monograph is largely self-contained and develops the harmonic analysis of several complex variables from the first principles. The text includes copious examples, explanations, an exhaustive bibliography for further reading, and figures that illustrate the geometric nature of the subject. Each chapter ends with an exercise set. Additionally, each chapter begins with a prologue, introducing the reader to the subject matter that follows; capsules presented in each section give perspective and a spirited launch to the segment; preludes help put ideas into context. Mathematicians and...

  10. The path-integral analysis of an associative memory model storing an infinite number of finite limit cycles

    International Nuclear Information System (INIS)

    Mimura, Kazushi; Kawamura, Masaki; Okada, Masato

    2004-01-01

    An exact solution of the transient dynamics of an associative memory model storing an infinite number of limit cycles with l finite steps is shown by means of the path-integral analysis. Assuming the Maxwell construction ansatz, we have succeeded in deriving the stationary state equations of the order parameters from the macroscopic recursive equations with respect to the finite-step sequence processing model which has retarded self-interactions. We have also derived the stationary state equations by means of the signal-to-noise analysis (SCSNA). The signal-to-noise analysis must assume that crosstalk noise of an input to spins obeys a Gaussian distribution. On the other hand, the path-integral method does not require such a Gaussian approximation of crosstalk noise. We have found that both the signal-to-noise analysis and the path-integral analysis give completely the same result with respect to the stationary state in the case where the dynamics is deterministic, when we assume the Maxwell construction ansatz. We have shown the dependence of the storage capacity (α c ) on the number of patterns per one limit cycle (l). At l = 1, the storage capacity is α c = 0.138 as in the Hopfield model. The storage capacity monotonically increases with the number of steps, and converges to α c = 0.269 at l ≅ 10. The original properties of the finite-step sequence processing model appear as long as the number of steps of the limit cycle has order l = O(1)

  11. Impact of Maternal Death on Household Economy in Rural China: A Prospective Path Analysis.

    Science.gov (United States)

    Ye, Fang; Ao, Deng; Feng, Yao; Wang, Lin; Chen, Jie; Huntington, Dale; Wang, Haijun; Wang, Yan

    2015-01-01

    The present study aimed to explore the inter-relationships among maternal death, household economic status after the event, and potential influencing factors. We conducted a prospective cohort study of households that had experienced maternal death (n = 195) and those that experienced childbirth without maternal death (n = 384) in rural China. All the households were interviewed after the event occurred and were followed up 12 months later. Structural equation modeling was used to test the relationship model, utilizing income and expenditure per capita in the following year after the event as the main outcome variables, maternal death as the predictor, and direct costs, the amount of money offset by positive and negative coping strategies, whether the husband remarried, and whether the newborn was alive as the mediators. In the following year after the event, the path analysis revealed a direct effect from maternal death to lower income per capita (standardized coefficient = -0.43, p = 0.041) and to lower expenditure per capita (standardized coefficient = -0.51, peconomy. The results provided evidence for better understanding the mechanism of how this event affects a household economy and provided a reference for social welfare policies to target the most vulnerable households that have suffered from maternal deaths.

  12. Influence of Processing Parameters on the Flow Path in Friction Stir Welding

    Science.gov (United States)

    Schneider, J. A.; Nunes, A. C., Jr.

    2006-01-01

    Friction stir welding (FSW) is a solid phase welding process that unites thermal and mechanical aspects to produce a high quality joint. The process variables are rpm, translational weld speed, and downward plunge force. The strain-temperature history of a metal element at each point on the cross-section of the weld is determined by the individual flow path taken by the particular filament of metal flowing around the tool as influenced by the process variables. The resulting properties of the weld are determined by the strain-temperature history. Thus to control FSW properties, improved understanding of the processing parameters on the metal flow path is necessary.

  13. Cluster analysis for applications

    CERN Document Server

    Anderberg, Michael R

    1973-01-01

    Cluster Analysis for Applications deals with methods and various applications of cluster analysis. Topics covered range from variables and scales to measures of association among variables and among data units. Conceptual problems in cluster analysis are discussed, along with hierarchical and non-hierarchical clustering methods. The necessary elements of data analysis, statistics, cluster analysis, and computer implementation are integrated vertically to cover the complete path from raw data to a finished analysis.Comprised of 10 chapters, this book begins with an introduction to the subject o

  14. Estimates of genetic parameters and path analysis in lentil (lens culinaris medik)

    International Nuclear Information System (INIS)

    Younis, N.; Hanif, M.; Sadiq, S.; Abbas, G.; Asghar, M.J.; Haq, M.A.

    2008-01-01

    These studies were conducted to determine the genetic parameters and character association in elite lines 0 lentil (Lens culinaris Medik).Genetic parameters like genotypic and phenotypic variances, coefficients of variation heritability, genetic advance, correlation coefficients and path coefficients were estimated. Significant variation was noted for all the traits. High heritability estimates were observed for all the traits except number of primary branches per plant. In general phenotypic coefficients of variability were greater than their corresponding genotypic coefficient of variability. Higher estimates of heritability and genetic advance were observed for seed yield (97.10%, 90.71%), harvest index (96.20%, 63.29%) and maturity days (95.90%, 63.39%) indicating the these characters are mainly controlled by additive genes and selection of such traits might be effective for the improvement of seed yield. Days to flower, plant height, number of primary branches, biological yield, harvest index and hundred seed weight had positive direct effect on seed yield. Biological yield, hundred seed weight and harvest index also had positive and highly significant genotypic and phenotypic correlation with seed yield. Hence these traits could be used for the improvement of seed yield resulting in the evolution of high yielding varieties 0 lentil. (author)

  15. Feynman's path integrals and Bohm's particle paths

    International Nuclear Information System (INIS)

    Tumulka, Roderich

    2005-01-01

    Both Bohmian mechanics, a version of quantum mechanics with trajectories, and Feynman's path integral formalism have something to do with particle paths in space and time. The question thus arises how the two ideas relate to each other. In short, the answer is, path integrals provide a re-formulation of Schroedinger's equation, which is half of the defining equations of Bohmian mechanics. I try to give a clear and concise description of the various aspects of the situation. (letters and comments)

  16. Genotypic Correlation and Path Analysis of Some Traits related to Oil Yield and Grain Yield in Canola (Brassica napus L. under Non-stress and Water Deficit Stress Conditions

    Directory of Open Access Journals (Sweden)

    A Ismaili

    2017-03-01

    Full Text Available Introduction Obtaining varieties with acceptable yield and tolerant to different arid and semi-arid climate condition of Iran is an important goal in canola breeding programs. Selection of genotypes base on one or more traits without regarding to correlation between them, could biases the expected results. Therefore, identifying of genetic correlation among traits especially in environmental stress condition is very important. The use of genotypic correlation helps evaluating the magnitude and direction of associations between characters facilitating the application of indirect selection, because genetic changes in a given trait may change other traits, leading to faster and larger genetic gains in plant breeding programs. Therefore, the selection for another trait may result in indirect response in the low heritable trait, provided the following conditions are satisfied: the genetic correlation between them is substantial, and the heritability of the secondary trait is greater than that of the primary trait. The purpose of this study was estimating the total genotypic variability, genotypic correlations, and path analysis among some important traits for selection criteria for improving seed and oil yield in canola under water deficit stress condition. Materials and Methods For evaluation of genetic correlation among traits and identifying important affecting traits on grain yield and oil yield in canola genotypes, an experiment was conducted based on a randomized complete blocks design with three replications in two different conditions of water deficit (stress and non-stress. Different traits were measured including seed yield, 1000-seed weight, number of seeds per pod, number of pods per plant, silique length, oil content, days to maturity, protein content, plant height and water use efficiency. Genotypic and phenotypic correlation coefficients were calculated for ten characters during growing seasons. The genotypic correlation coefficients

  17. A Model of Aging Perception in Iranian Elders With Effects of Hope, Life Satisfaction, and Socioeconomic Status: A Path Analysis.

    Science.gov (United States)

    Yaghoobzadeh, Ameneh; Gorgulu, Ozkan; Yee, Bit-Lian; Wibisono, Ahmad Hasyim; Pahlevan Sharif, Saeed; Sharif Nia, Hamid; Allen, Kelly A

    2018-01-01

    Aging perception plays a central role in the experience of healthy aging by older people. Research identified that factors such as hope, life satisfaction, and socioeconomic status influence the perception of aging in older populations. This study sought to test a hypothetical model to quantitatively evaluate the relationship between hope, life satisfaction, and socioeconomic status with aging perception. A cross-sectional design was used with 504 older aged participants who live in Qazvin, Iran. Data were collected using the Barker's Aging Perception Questionnaire, Life Satisfaction Index-Z, and Herth Hope Index. The results of path analysis showed that hope was the most important factor affecting aging perception. Results drawn from correlation analysis indicated that there was a positive significant correlation ( r = .383, p hope and aging perception. Further analysis found that hope had the strongest impact on aging perception compared with the other variables analyzed (e.g., life satisfaction and socioeconomic status). A model of aging perception in Iranian elders is presented. The findings suggested that hope had a significant and positive impact on aging perception. Implications for clinical practice and research are discussed.

  18. An Empirical Path-Loss Model for Wireless Channels in Indoor Short-Range Office Environment

    Directory of Open Access Journals (Sweden)

    Ye Wang

    2012-01-01

    Full Text Available A novel empirical path-loss model for wireless indoor short-range office environment at 4.3–7.3 GHz band is presented. The model is developed based on the experimental datum sampled in 30 office rooms in both line of sight (LOS and non-LOS (NLOS scenarios. The model is characterized as the path loss to distance with a Gaussian random variable X due to the shadow fading by using linear regression. The path-loss exponent n is fitted by the frequency using power function and modeled as a frequency-dependent Gaussian variable as the standard deviation σ of X. The presented works should be available for the research of wireless channel characteristics under universal indoor short-distance environments in the Internet of Things (IOT.

  19. Cumulative trauma, hyperarousal, and suicidality in the general population: a path analysis.

    Science.gov (United States)

    Briere, John; Godbout, Natacha; Dias, Colin

    2015-01-01

    Although trauma exposure and posttraumatic stress disorder (PTSD) both have been linked to suicidal thoughts and behavior, the underlying basis for this relationship is not clear. In a sample of 357 trauma-exposed individuals from the general population, younger participant age, cumulative trauma exposure, and all three Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, PTSD clusters (reexperiencing, avoidance, and hyperarousal) were correlated with clinical levels of suicidality. However, logistic regression analysis indicated that when all PTSD clusters were considered simultaneously, only hyperarousal continued to be predictive. A path analysis confirmed that posttraumatic hyperarousal (but not other components of PTSD) fully mediated the relationship between extent of trauma exposure and degree of suicidal thoughts and behaviors.

  20. Polygonal-path approximations on the path spaces of quantum-mechanical systems: properties of the polygonal paths

    International Nuclear Information System (INIS)

    Exner, P.; Kolerov, G.I.

    1981-01-01

    Properties of the subset of polygonal paths in the Hilbert space H of paths referring to a d-dimensional quantum-mechanical system are examined. Using the reproduction kernel technique we prove that each element of H is approximated by polygonal paths uniformly with respect to the ''norm'' of time-interval partitions. This result will be applied in the second part of the present paper to prove consistency of the uniform polygonal-path extension of the Feynman maps [ru

  1. The importance of position and path repeatability on force at the knee during six-DOF joint motion.

    Science.gov (United States)

    Darcy, Shon P; Gil, Jorge E; Woo, Savio L-Y; Debski, Richard E

    2009-06-01

    Mechanical devices, such as robotic manipulators have been designed to measure joint and ligament function because of their ability to position a diarthrodial joint in six degrees-of-freedom with fidelity. However, the precision and performance of these testing devices vary. Therefore, the objective of this study was to determine the effect of systematic errors in position and path repeatability of two high-payload robotic manipulators (Manipulators 1 and 2) on the resultant forces at the knee. Using a porcine knee, the position and path repeatability of these manipulators were determined during passive flexion-extension with a coordinate measuring machine. The position repeatability of Manipulator 1 was 0.3 mm in position and 0.2 degrees in orientation while Manipulator 2 had a better position repeatability of 0.1 mm in position and 0.1 degrees in orientation throughout the range of positions examined. The corresponding variability in the resultant force at the knee for these assigned positions was 32+/-33 N for Manipulator 1 and 4+/-1 N for Manipulator 2. Furthermore, the repeatability of the trajectory of each manipulator while moving between assigned positions (path repeatability) was 0.8 mm for Manipulator 1 while the path repeatability for Manipulator 2 was improved (0.1 mm). These path discrepancies produced variability in the resultant force at the knee of 44+/-24 and 21+/-8 N, respectively, for Manipulators 1 and 2 primarily due to contact between the articular surfaces of the tibia and femur. Therefore, improved position and path repeatability yields lower variability in the resultant forces at the knee. Although position repeatability has been the most common criteria for evaluating biomechanical testing devices, the current study has clearly demonstrated that path repeatability can have an even larger effect on the variability in resultant force at the knee. Consequently, the repeatability of the path followed by the joint throughout its prescribed

  2. Radiation oncology career decision variables for graduating trainees seeking positions in 2003-2004

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Lynn D [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT (United States); Flynn, Daniel F [Department of Radiation Oncology, Holy Family Hospital, Methuen, MA (United States); Haffty, Bruce G [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT (United States)

    2005-06-01

    Purpose: Radiation oncology trainees must consider an array of variables when deciding upon an academic or private practice career path. This prospective evaluation of the 2004 graduating radiation oncology trainees, evaluates such variables and provides additional descriptive data. Methods: A survey that included 15 questions (one subjective, eleven categorical, and 3 continuous variables) was mailed to the 144 graduating radiation oncology trainees in United States programs in January of 2004. Questions were designed to gather information regarding factors that may have influenced career path choices. The responses were anonymous, and no identifying information was sought. Survey data were collated and analyzed for differences in both categorical and continuous variables as they related to choice of academic or private practice career path. Results: Sixty seven (47%) of the surveys were returned. Forty-five percent of respondents indicated pursuit of an academic career. All respondents participated in research during training with 73% participating in research publication authorship. Post graduate year-3 was the median in which career path was chosen, and 20% thought that a fellowship position was 'perhaps' necessary to secure an academic position. Thirty percent of the respondents revealed that the timing of the American Board of Radiology examination influenced their career path decision. Eighteen variables were offered as possibly influencing career path choice within the survey, and the top five identified by those seeking an academic path were: (1) colleagues, (2) clinical research, (3) teaching, (4) geography, (5) and support staff. For those seeking private practice, the top choices were: (1) lifestyle, (2) practice environment, (3) patient care, (4) geography, (5) colleagues. Female gender (p = 0.064), oral meeting presentation (p = 0.053), and international meeting presentation (p 0.066) were the variables most significantly associated with pursuing an

  3. Radiation oncology career decision variables for graduating trainees seeking positions in 2003-2004

    International Nuclear Information System (INIS)

    Wilson, Lynn D.; Flynn, Daniel F.; Haffty, Bruce G.

    2005-01-01

    Purpose: Radiation oncology trainees must consider an array of variables when deciding upon an academic or private practice career path. This prospective evaluation of the 2004 graduating radiation oncology trainees, evaluates such variables and provides additional descriptive data. Methods: A survey that included 15 questions (one subjective, eleven categorical, and 3 continuous variables) was mailed to the 144 graduating radiation oncology trainees in United States programs in January of 2004. Questions were designed to gather information regarding factors that may have influenced career path choices. The responses were anonymous, and no identifying information was sought. Survey data were collated and analyzed for differences in both categorical and continuous variables as they related to choice of academic or private practice career path. Results: Sixty seven (47%) of the surveys were returned. Forty-five percent of respondents indicated pursuit of an academic career. All respondents participated in research during training with 73% participating in research publication authorship. Post graduate year-3 was the median in which career path was chosen, and 20% thought that a fellowship position was 'perhaps' necessary to secure an academic position. Thirty percent of the respondents revealed that the timing of the American Board of Radiology examination influenced their career path decision. Eighteen variables were offered as possibly influencing career path choice within the survey, and the top five identified by those seeking an academic path were: (1) colleagues, (2) clinical research, (3) teaching, (4) geography, (5) and support staff. For those seeking private practice, the top choices were: (1) lifestyle, (2) practice environment, (3) patient care, (4) geography, (5) colleagues. Female gender (p = 0.064), oral meeting presentation (p = 0.053), and international meeting presentation (p 0.066) were the variables most significantly associated with pursuing an

  4. Path integral for a relativistic-particle theory

    Energy Technology Data Exchange (ETDEWEB)

    Fradkin, E.S. (AN SSSR, Moscow (SU)); Gitman, D.M. (Moskovskij Inst. Radiotekhniki, Ehlektroniki i Automatiki, Moscow (SU)); Shvartsman, S.M. (Tomskij Pedagogicheskij Inst., Tomsk (SU))

    1991-06-01

    An action of a relativistic spinning particle written in reparametrization and local super-invariant form is consistently determined by using the path integral representation for the Green's function of the spinor field. It is shown that, to obtain the causal propagator, the integration over the null mode of the onebein variable must be performed in the (0, + {infinity}) limits.

  5. Automatically visualise and analyse data on pathways using PathVisioRPC from any programming environment.

    Science.gov (United States)

    Bohler, Anwesha; Eijssen, Lars M T; van Iersel, Martijn P; Leemans, Christ; Willighagen, Egon L; Kutmon, Martina; Jaillard, Magali; Evelo, Chris T

    2015-08-23

    Biological pathways are descriptive diagrams of biological processes widely used for functional analysis of differentially expressed genes or proteins. Primary data analysis, such as quality control, normalisation, and statistical analysis, is often performed in scripting languages like R, Perl, and Python. Subsequent pathway analysis is usually performed using dedicated external applications. Workflows involving manual use of multiple environments are time consuming and error prone. Therefore, tools are needed that enable pathway analysis directly within the same scripting languages used for primary data analyses. Existing tools have limited capability in terms of available pathway content, pathway editing and visualisation options, and export file formats. Consequently, making the full-fledged pathway analysis tool PathVisio available from various scripting languages will benefit researchers. We developed PathVisioRPC, an XMLRPC interface for the pathway analysis software PathVisio. PathVisioRPC enables creating and editing biological pathways, visualising data on pathways, performing pathway statistics, and exporting results in several image formats in multiple programming environments. We demonstrate PathVisioRPC functionalities using examples in Python. Subsequently, we analyse a publicly available NCBI GEO gene expression dataset studying tumour bearing mice treated with cyclophosphamide in R. The R scripts demonstrate how calls to existing R packages for data processing and calls to PathVisioRPC can directly work together. To further support R users, we have created RPathVisio simplifying the use of PathVisioRPC in this environment. We have also created a pathway module for the microarray data analysis portal ArrayAnalysis.org that calls the PathVisioRPC interface to perform pathway analysis. This module allows users to use PathVisio functionality online without having to download and install the software and exemplifies how the PathVisioRPC interface can be

  6. A career path in clinical pathways.

    Science.gov (United States)

    Bower, K A

    1998-03-01

    Much like the development of a clinical path, the creation of a career path requires knowledge of patterns of behavior, needs for standardized education and skill development, along with variance analysis and individualized care. This nationally known nursing entrepreneur tells the story of her involvement in the development of case management and clinical pathways and how she turned that into a successful business that has changed how patient care is managed nationally and internationally.

  7. Habitat mosaics and path analysis can improve biological conservation of aquatic biodiversity in ecosystems with low-head dams.

    Science.gov (United States)

    Hitchman, Sean M; Mather, Martha E; Smith, Joseph M; Fencl, Jane S

    2018-04-01

    Conserving native biodiversity depends on restoring functional habitats in the face of human-induced disturbances. Low-head dams are a ubiquitous human impact that degrades aquatic ecosystems worldwide. To improve our understanding of how low-head dams impact habitat and associated biodiversity, our research examined complex interactions among three spheres of the total environment. i.e., how low-head dams (anthroposphere) affect aquatic habitat (hydrosphere), and native biodiversity (biosphere) in streams and rivers. Creation of lake-like habitats upstream of low-head dams is a well-documented major impact of dams. Alterations downstream of low head dams also have important consequences, but these downstream dam effects are more challenging to detect. In a multidisciplinary field study at five dammed and five undammed sites within the Neosho River basin, KS, we tested hypotheses about two types of habitat sampling (transect and mosaic) and two types of statistical analyses (analysis of covariance and path analysis). We used fish as our example of biodiversity alteration. Our research provided three insights that can aid environmental professionals who seek to conserve and restore fish biodiversity in aquatic ecosystems threatened by human modifications. First, a mosaic approach identified habitat alterations below low-head dams (e.g. increased proportion of riffles) that were not detected using the more commonly-used transect sampling approach. Second, the habitat mosaic approach illustrated how low-head dams reduced natural variation in stream habitat. Third, path analysis, a statistical approach that tests indirect effects, showed how dams, habitat, and fish biodiversity interact. Specifically, path analysis revealed that low-head dams increased the proportion of riffle habitat below dams, and, as a result, indirectly increased fish species richness. Furthermore, the pool habitat that was created above low-head dams dramatically decreased fish species richness

  8. Habitat mosaics and path analysis can improve biological conservation of aquatic biodiversity in ecosystems with low-head dams

    Science.gov (United States)

    Hitchman, Sean M.; Mather, Martha E.; Smith, Joseph M.; Fencl, Jane S.

    2018-01-01

    Conserving native biodiversity depends on restoring functional habitats in the face of human-induced disturbances. Low-head dams are a ubiquitous human impact that degrades aquatic ecosystems worldwide. To improve our understanding of how low-head dams impact habitat and associated biodiversity, our research examined complex interactions among three spheres of the total environment. i.e., how low-head dams (anthroposphere) affect aquatic habitat (hydrosphere), and native biodiversity (biosphere) in streams and rivers. Creation of lake-like habitats upstream of low-head dams is a well-documented major impact of dams. Alterations downstream of low head dams also have important consequences, but these downstream dam effects are more challenging to detect. In a multidisciplinary field study at five dammed and five undammed sites within the Neosho River basin, KS, we tested hypotheses about two types of habitat sampling (transect and mosaic) and two types of statistical analyses (analysis of covariance and path analysis). We used fish as our example of biodiversity alteration. Our research provided three insights that can aid environmental professionals who seek to conserve and restore fish biodiversity in aquatic ecosystems threatened by human modifications. First, a mosaic approach identified habitat alterations below low-head dams (e.g. increased proportion of riffles) that were not detected using the more commonly-used transect sampling approach. Second, the habitat mosaic approach illustrated how low-head dams reduced natural variation in stream habitat. Third, path analysis, a statistical approach that tests indirect effects, showed how dams, habitat, and fish biodiversity interact. Specifically, path analysis revealed that low-head dams increased the proportion of riffle habitat below dams, and, as a result, indirectly increased fish species richness. Furthermore, the pool habitat that was created above low-head dams dramatically decreased fish species

  9. Position and Attitude Alternate of Path Tracking Heading Control

    Directory of Open Access Journals (Sweden)

    Baocheng Tan

    2014-03-01

    Full Text Available The path tracking control algorithm is one of the key problems in the control system design of autonomous vehicle. In this paper, we have conducted dynamic modeling for autonomous vehicle, the relationship between course deviation and yaw rate and centroid deflection angle. From the angle of the dynamics and geometrical, this paper have described the path tracking problem, analyzed the emergence of the eight autonomous vehicles pose binding - position and attitude alternate control methods to identify the relationship between posture and the controlling variables, and design a controller, the experimental results verify the feasibility and effectiveness of this control method.

  10. MOCUS, Minimal Cut Sets and Minimal Path Sets from Fault Tree Analysis

    International Nuclear Information System (INIS)

    Fussell, J.B.; Henry, E.B.; Marshall, N.H.

    1976-01-01

    1 - Description of problem or function: From a description of the Boolean failure logic of a system, called a fault tree, and control parameters specifying the minimal cut set length to be obtained MOCUS determines the system failure modes, or minimal cut sets, and the system success modes, or minimal path sets. 2 - Method of solution: MOCUS uses direct resolution of the fault tree into the cut and path sets. The algorithm used starts with the main failure of interest, the top event, and proceeds to basic independent component failures, called primary events, to resolve the fault tree to obtain the minimal sets. A key point of the algorithm is that an and gate alone always increases the number of path sets; an or gate alone always increases the number of cut sets and increases the size of path sets. Other types of logic gates must be described in terms of and and or logic gates. 3 - Restrictions on the complexity of the problem: Output from MOCUS can include minimal cut and path sets for up to 20 gates

  11. Zero Distribution of System with Unknown Random Variables Case Study: Avoiding Collision Path

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    Parman Setyamartana

    2014-07-01

    Full Text Available This paper presents the stochastic analysis of finding the feasible trajectories of robotics arm motion at obstacle surrounding. Unknown variables are coefficients of polynomials joint angle so that the collision-free motion is achieved. ãk is matrix consisting of these unknown feasible polynomial coefficients. The pattern of feasible polynomial in the obstacle environment shows as random. This paper proposes to model the pattern of this randomness values using random polynomial with unknown variables as coefficients. The behavior of the system will be obtained from zero distribution as the characteristic of such random polynomial. Results show that the pattern of random polynomial of avoiding collision can be constructed from zero distribution. Zero distribution is like building block of the system with obstacles as uncertainty factor. By scale factor k, which has range, the random coefficient pattern can be predicted.

  12. Consistent Partial Least Squares Path Modeling via Regularization.

    Science.gov (United States)

    Jung, Sunho; Park, JaeHong

    2018-01-01

    Partial least squares (PLS) path modeling is a component-based structural equation modeling that has been adopted in social and psychological research due to its data-analytic capability and flexibility. A recent methodological advance is consistent PLS (PLSc), designed to produce consistent estimates of path coefficients in structural models involving common factors. In practice, however, PLSc may frequently encounter multicollinearity in part because it takes a strategy of estimating path coefficients based on consistent correlations among independent latent variables. PLSc has yet no remedy for this multicollinearity problem, which can cause loss of statistical power and accuracy in parameter estimation. Thus, a ridge type of regularization is incorporated into PLSc, creating a new technique called regularized PLSc. A comprehensive simulation study is conducted to evaluate the performance of regularized PLSc as compared to its non-regularized counterpart in terms of power and accuracy. The results show that our regularized PLSc is recommended for use when serious multicollinearity is present.

  13. Consistent Partial Least Squares Path Modeling via Regularization

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    Sunho Jung

    2018-02-01

    Full Text Available Partial least squares (PLS path modeling is a component-based structural equation modeling that has been adopted in social and psychological research due to its data-analytic capability and flexibility. A recent methodological advance is consistent PLS (PLSc, designed to produce consistent estimates of path coefficients in structural models involving common factors. In practice, however, PLSc may frequently encounter multicollinearity in part because it takes a strategy of estimating path coefficients based on consistent correlations among independent latent variables. PLSc has yet no remedy for this multicollinearity problem, which can cause loss of statistical power and accuracy in parameter estimation. Thus, a ridge type of regularization is incorporated into PLSc, creating a new technique called regularized PLSc. A comprehensive simulation study is conducted to evaluate the performance of regularized PLSc as compared to its non-regularized counterpart in terms of power and accuracy. The results show that our regularized PLSc is recommended for use when serious multicollinearity is present.

  14. Genetic variability, trait association and path analysis of yield and yield components in mungbean (vigna radiata (L.) wilczek)

    International Nuclear Information System (INIS)

    Tabasum, A.; Saleem, M.; Aziz, I.

    2010-01-01

    Genetic variability, heritability along with genetic advance of traits, their association and direct and indirect effects on yield are essential for crop improvement. Ten mungbean genotypes were studied to assess variability and degree to which various plant traits associate with seed yield. Primary and secondary branches, pods per cluster and pod length showed lesser variability while clusters per plant, 100 seed weight and harvest index exhibited intermediate range of variability. Sufficient genetic variability was observed for plant height, pods per plant, total plant weight and seed yield. Moderate to high heritability estimates were found for all traits. Primary and secondary branches per plant, pod length and 100-seed weight exhibited negative and non significant genotypic and phenotypic correlations with seed yield. Plant height showed positive non-significant and significant genotypic and phenotypic correlation. Pods per cluster correlated significantly negative with seed yield. Clusters per plant, pods per plant, total plant weight and harvest index showed positive significant genotypic and phenotypic correlations with seed yield. Positive direct effects were exerted through secondary branches, pods per plant, pod length, 100 seed weight, total plant weight and harvest index while primary branches, plant height, clusters per plant and pods per cluster had negative direct effects. The present findings could be useful for establishing selection criteria for high seed yield in the mungbean breeding. (author)

  15. Definition of path integrals and rules for non-linear transformations

    International Nuclear Information System (INIS)

    Kerler, W.

    1978-01-01

    Functional integrals are defined as the limit of multidimensional integrals based on fundamental generating distributions. The 'lattice choice' is put into a suitable functional form. The independence of the particular choice and the necessity of this fact are shown. Various forms of the path integrals are derived and discussed. The relation to the traditional ordering problem is pointed out. The mechanism of non-linear transformations of variables is investigated and rules are given. In the case of fields it turns out that the path integrals can also be considered for space translations. (Auth.)

  16. Methodology for using root locus technique for mobile robots path planning

    Directory of Open Access Journals (Sweden)

    Mario Ricardo Arbulú Saavedra

    2015-11-01

    Full Text Available This paper shows the analysis and the implementation methodology of the technique of dynamic systems roots location used in free-obstacle path planning for mobile robots. First of all, the analysis and morphologic behavior identification of the paths depending on roots location in complex plane are performed, where paths type and their attraction and repulsion features in the presence of other roots similarly to the obtained with artificial potential fields are identified. An implementation methodology for this technique of mobile robots path planning is proposed, starting from three different methods of roots location for obstacles in the scene. Those techniques change depending on the obstacle key points selected for roots, such as borders, crossing points with original path, center and vertices. Finally, a behavior analysis of general technique and the effectiveness of each tried method is performed, doing 20 tests for each one, obtaining a value of 65% for the selected method. Modifications and possible improvements to this methodology are also proposed.

  17. Application of Statistical Method of Path Analysis to Describe Soil Biological Indices

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    Y. Kooch

    2016-09-01

    Full Text Available Introduction: Among the collection of natural resources in the world, soil is considered as one of the most important components of the environment. Protect and improve the properties of this precious resource, requires a comprehensive and coordinated action that only through a deep understanding of quantitative (not only recognition of the quality the origin, distribution and functionality in a natural ecosystem is possible. Many researchers believe that due to the quick reactions of soil organisms to environmental changes, soil biological survey to estimate soil quality is more important than the chemical and physical properties. For this reason, in many studies the nitrogen mineralization and microbial respiration indices are regarded. The aim of the present study were to study the direct and indirect effects of soil physicochemical characteristics on the most important biological indicators (nitrogen mineralization and microbial respiration, which has not been carefully considered up to now. This research is the first study to provide evidence to the future planning and management of soil sciences. Materials and Methods: For this, a limitation of 20 ha area of Experimental Forest Station of Tarbiat Modares University was considered. Fifty five soil samples, from the top 15 cm of soil, were taken, from which bulk density, texture, organic C, total N, cation exchange capacity (CEC, nitrogen mineralization and microbial respiration were determined at the laboratory. The data stored in Excel as a database. To determine the relationship between biological indices and soil physicochemical characteristics, correlation analysis and factor analysis using principal component analysis (PCA were employed. To investigate all direct and indirect relationships between biological indices and different soil characteristics, path analysis (path analysis was used. Results and Discussion: Results showed significant positive relations between biological indices

  18. Cumulative trauma and symptom complexity in children: a path analysis.

    Science.gov (United States)

    Hodges, Monica; Godbout, Natacha; Briere, John; Lanktree, Cheryl; Gilbert, Alicia; Kletzka, Nicole Taylor

    2013-11-01

    Multiple trauma exposures during childhood are associated with a range of psychological symptoms later in life. In this study, we examined whether the total number of different types of trauma experienced by children (cumulative trauma) is associated with the complexity of their subsequent symptomatology, where complexity is defined as the number of different symptom clusters simultaneously elevated into the clinical range. Children's symptoms in six different trauma-related areas (e.g., depression, anger, posttraumatic stress) were reported both by child clients and their caretakers in a clinical sample of 318 children. Path analysis revealed that accumulated exposure to multiple different trauma types predicts symptom complexity as reported by both children and their caretakers. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Strain path and work-hardening behavior of brass

    International Nuclear Information System (INIS)

    Sakharova, N.A.; Fernandes, J.V.; Vieira, M.F.

    2009-01-01

    Plastic straining in metal forming usually includes changes of strain path, which are frequently not taken into account in the analysis of forming processes. Moreover, strain path change can significantly affect the mechanical behavior and microstructural evolution of the material. For this reason, a combination of several simple loading test sequences is an effective way to investigate the dislocation microstructure of sheet metals under such forming conditions. Pure tension and rolling strain paths and rolling-tension strain path sequences were performed on brass sheets. A study of mechanical behavior and microstructural evolution during the simple and the complex strain paths was carried out, within a wide range of strain values. The appearance and development of deformation twinning was evident. It was shown that strain path change promotes the onset of premature twinning. The work-hardening behavior is discussed in terms of the twinning and dislocation microstructure evolution, as revealed by transmission electron microscopy

  20. Path analysis suggests phytoene accumulation is the key step limiting the carotenoid pathway in white carrot roots

    Directory of Open Access Journals (Sweden)

    Carlos Antonio Fernandes Santos

    2005-01-01

    Full Text Available Two F2 carrot (Daucus carota L. populations (orange rooted Brasilia x very dark orange rooted High Carotene Mass - HCM cross and the dark orange rooted cultivated variety B493 x white rooted wild carrot Queen Anne's Lace - QAL cross with very unrelated genetic backgrounds were used to investigate intrinsic factors limiting carotenoid accumulation in carrots by applying phenotypic correlation and path analysis to study the relationships between major root carotenes, root color and several other morphological traits. Most of the correlations between traits were close and agreed in sign between the two populations. Root weight had a moderate to highly significant positive correlation with leaf length, root length and top and middle root diameter. Although phenotypic correlations failed to identify the order of the substrates and products in the carotenoid pathway the correct order of substrates and products (phytoene -> zeta-carotene -> lycopene was identified in the causal diagram of beta-carotene for the Brasilia x HCM population. Path analysis of beta-carotene synthesis in the B493 x QAL population suggested that selection for root carotenes had little effect on plant morphological traits. Causal model of beta-carotene and lycopene in the B493 x QAL population suggested that phytoene synthesis is the key step limiting the carotenoid pathway in white carrots. Path analysis, first presented by Sewall Wright to study quantitative traits, appears to be a powerful statistical approach for the identification of key compounds in complex pathways.

  1. Long open-path measurements of greenhouse gases in air using near-infrared Fourier transform spectroscopy

    Directory of Open Access Journals (Sweden)

    D. W. T. Griffith

    2018-03-01

    Full Text Available In complex and urban environments, atmospheric trace gas composition is highly variable in time and space. Point measurement techniques for trace gases with in situ instruments are well established and accurate, but do not provide spatial averaging to compare against developing high-resolution atmospheric models of composition and meteorology with resolutions of the order of a kilometre. Open-path measurement techniques provide path average concentrations and spatial averaging which, if sufficiently accurate, may be better suited to assessment and interpretation with such models. Open-path Fourier transform spectroscopy (FTS in the mid-infrared region, and differential optical absorption spectroscopy (DOAS in the UV and visible, have been used for many years for open-path spectroscopic measurements of selected species in both clean air and in polluted environments. Near infrared instrumentation allows measurements over longer paths than mid-infrared FTS for species such as greenhouse gases which are not easily accessible to DOAS.In this pilot study we present the first open-path near-infrared (4000–10 000 cm−1, 1.0–2.5 µm FTS measurements of CO2, CH4, O2, H2O and HDO over a 1.5 km path in urban Heidelberg, Germany. We describe the construction of the open-path FTS system, the analysis of the collected spectra, several measures of precision and accuracy of the measurements, and the results a four-month trial measurement period in July–November 2014. The open-path measurements are compared to calibrated in situ measurements made at one end of the open path. We observe significant differences of the order of a few ppm for CO2 and a few tens of ppb for CH4 between the open-path and point measurements which are 2 to 4 times the measurement repeatability, but we cannot unequivocally assign the differences to specific local sources or sinks. We conclude that open-path FTS may provide a valuable new tool for investigations of

  2. Pulled Motzkin paths

    International Nuclear Information System (INIS)

    Janse van Rensburg, E J

    2010-01-01

    In this paper the models of pulled Dyck paths in Janse van Rensburg (2010 J. Phys. A: Math. Theor. 43 215001) are generalized to pulled Motzkin path models. The generating functions of pulled Motzkin paths are determined in terms of series over trinomial coefficients and the elastic response of a Motzkin path pulled at its endpoint (see Orlandini and Whittington (2004 J. Phys. A: Math. Gen. 37 5305-14)) is shown to be R(f) = 0 for forces pushing the endpoint toward the adsorbing line and R(f) = f(1 + 2cosh f))/(2sinh f) → f as f → ∞, for forces pulling the path away from the X-axis. In addition, the elastic response of a Motzkin path pulled at its midpoint is shown to be R(f) = 0 for forces pushing the midpoint toward the adsorbing line and R(f) = f(1 + 2cosh (f/2))/sinh (f/2) → 2f as f → ∞, for forces pulling the path away from the X-axis. Formal combinatorial identities arising from pulled Motzkin path models are also presented. These identities are the generalization of combinatorial identities obtained in directed paths models to their natural trinomial counterparts.

  3. Pulled Motzkin paths

    Energy Technology Data Exchange (ETDEWEB)

    Janse van Rensburg, E J, E-mail: rensburg@yorku.c [Department of Mathematics and Statistics, York University, Toronto, ON, M3J 1P3 (Canada)

    2010-08-20

    In this paper the models of pulled Dyck paths in Janse van Rensburg (2010 J. Phys. A: Math. Theor. 43 215001) are generalized to pulled Motzkin path models. The generating functions of pulled Motzkin paths are determined in terms of series over trinomial coefficients and the elastic response of a Motzkin path pulled at its endpoint (see Orlandini and Whittington (2004 J. Phys. A: Math. Gen. 37 5305-14)) is shown to be R(f) = 0 for forces pushing the endpoint toward the adsorbing line and R(f) = f(1 + 2cosh f))/(2sinh f) {yields} f as f {yields} {infinity}, for forces pulling the path away from the X-axis. In addition, the elastic response of a Motzkin path pulled at its midpoint is shown to be R(f) = 0 for forces pushing the midpoint toward the adsorbing line and R(f) = f(1 + 2cosh (f/2))/sinh (f/2) {yields} 2f as f {yields} {infinity}, for forces pulling the path away from the X-axis. Formal combinatorial identities arising from pulled Motzkin path models are also presented. These identities are the generalization of combinatorial identities obtained in directed paths models to their natural trinomial counterparts.

  4. Pulled Motzkin paths

    Science.gov (United States)

    Janse van Rensburg, E. J.

    2010-08-01

    In this paper the models of pulled Dyck paths in Janse van Rensburg (2010 J. Phys. A: Math. Theor. 43 215001) are generalized to pulled Motzkin path models. The generating functions of pulled Motzkin paths are determined in terms of series over trinomial coefficients and the elastic response of a Motzkin path pulled at its endpoint (see Orlandini and Whittington (2004 J. Phys. A: Math. Gen. 37 5305-14)) is shown to be R(f) = 0 for forces pushing the endpoint toward the adsorbing line and R(f) = f(1 + 2cosh f))/(2sinh f) → f as f → ∞, for forces pulling the path away from the X-axis. In addition, the elastic response of a Motzkin path pulled at its midpoint is shown to be R(f) = 0 for forces pushing the midpoint toward the adsorbing line and R(f) = f(1 + 2cosh (f/2))/sinh (f/2) → 2f as f → ∞, for forces pulling the path away from the X-axis. Formal combinatorial identities arising from pulled Motzkin path models are also presented. These identities are the generalization of combinatorial identities obtained in directed paths models to their natural trinomial counterparts.

  5. Path integral quantization of parametrized field theory

    International Nuclear Information System (INIS)

    Varadarajan, Madhavan

    2004-01-01

    Free scalar field theory on a flat spacetime can be cast into a generally covariant form known as parametrized field theory in which the action is a functional of the scalar field as well as the embedding variables which describe arbitrary, in general curved, foliations of the flat spacetime. We construct the path integral quantization of parametrized field theory in order to analyze issues at the interface of quantum field theory and general covariance in a path integral context. We show that the measure in the Lorentzian path integral is nontrivial and is the analog of the Fradkin-Vilkovisky measure for quantum gravity. We construct Euclidean functional integrals in the generally covariant setting of parametrized field theory using key ideas of Schleich and show that our constructions imply the existence of nonstandard 'Wick rotations' of the standard free scalar field two-point function. We develop a framework to study the problem of time through computations of scalar field two-point functions. We illustrate our ideas through explicit computation for a time independent (1+1)-dimensional foliation. Although the problem of time seems to be absent in this simple example, the general case is still open. We discuss our results in the contexts of the path integral formulation of quantum gravity and the canonical quantization of parametrized field theory

  6. Path lumping: An efficient algorithm to identify metastable path channels for conformational dynamics of multi-body systems

    Science.gov (United States)

    Meng, Luming; Sheong, Fu Kit; Zeng, Xiangze; Zhu, Lizhe; Huang, Xuhui

    2017-07-01

    Constructing Markov state models from large-scale molecular dynamics simulation trajectories is a promising approach to dissect the kinetic mechanisms of complex chemical and biological processes. Combined with transition path theory, Markov state models can be applied to identify all pathways connecting any conformational states of interest. However, the identified pathways can be too complex to comprehend, especially for multi-body processes where numerous parallel pathways with comparable flux probability often coexist. Here, we have developed a path lumping method to group these parallel pathways into metastable path channels for analysis. We define the similarity between two pathways as the intercrossing flux between them and then apply the spectral clustering algorithm to lump these pathways into groups. We demonstrate the power of our method by applying it to two systems: a 2D-potential consisting of four metastable energy channels and the hydrophobic collapse process of two hydrophobic molecules. In both cases, our algorithm successfully reveals the metastable path channels. We expect this path lumping algorithm to be a promising tool for revealing unprecedented insights into the kinetic mechanisms of complex multi-body processes.

  7. Efficacy-mediated effects of spirituality and physical activity on quality of life: A path analysis

    Directory of Open Access Journals (Sweden)

    Konopack James F

    2012-05-01

    Full Text Available Abstract Background Physical activity has been established as an important determinant of quality of life, particularly among older adults. Previous research has suggested that physical activity’s influence on quality of life perceptions is mediated by changes in self-efficacy and health status. In the same vein, spirituality may be a salient quality of life determinant for many individuals. Methods In the current study, we used path analysis to test a model in which physical activity, spirituality, and social support were hypothesized to influence global quality of life in paths mediated by self-efficacy and health status. Cross-sectional data were collected from a sample of 215 adults (male, n = 51; female, n = 164 over the age of 50 (M age = 66.55 years. Results The analysis resulted in a model that provided acceptable fit to the data (χ2 = 33.10, df = 16, p  Conclusions These results support previous findings of an efficacy-mediated relationship between physical activity and quality of life, with the exception that self-efficacy in the current study was moderately associated with physical health status (.38 but not mental health status. Our results further suggest that spirituality may influence health and well-being via a similar, efficacy-mediated path, with strongest effects on mental health status. These results suggest that those who are more spiritual and physically active report greater quality of life, and the effects of these factors on quality of life may be partially mediated by perceptions of self-efficacy.

  8. Sequential path analysis for determining interrelationships between yield and related traits in tobacco (Nicotiana tabacum L. under normal and abiotic stress conditions

    Directory of Open Access Journals (Sweden)

    Bayat Mahdi

    2014-01-01

    Full Text Available In the present work the relationships between yield and its related traits were investigated in tobacco genotypes under normal and abiotic stress conditions (Orobanche aegyptiaca weed at Urmia Tobacco Research Centre, Iran, during 2006-2009 cropping seasons. The experimental design was a randomized complete block design (RCBD with three replications in each condition every year. Analysis of variance revealed extent genetic variability among the genotypes for most of the traits studied. In comparison with normal condition, the mean value of studied traits decreased in stress condition. LAI and FD showed the maximum and minimum diminution in the mean values under stress condition compared to normal one so known as more sensitive and more tolerant traits, respectively. Based on CV values, the traits FD and DLYP showed the minimum and maximum variation among traits in both normal and stress conditions. Correlation analysis revealed significant and positive correlations between DLYP with all studied traits in both normal and stress conditions. Path analysis detected the traits including biomass, APDW and DWR as the first-order variables at normal condition and biomass, APDW, DWR and harvest index as the first-order variables under abiotic stress condition. Based on results, the traits such as biomass, APDW, DWR detected as more important factors in both conditions can be used in tobacco breeding programs for increasing yield. Abbreviation: aerial part fresh weight without leaves weight (APFW, aerial part dry weight without leaves weight (APDW, biomass (BIO, coefficient of variation (CV, dry weight of root (DWR, flowering date (FD, fresh weight of leaf (FWL, fresh weight of root (FWR, harvest index (HI, leaf area index (LAI, dry leaf yield per plant (DLYP, number of leaf (NL, plant height (PH, randomized complete block design (RCBD, standard deviation (Std.

  9. Approaching acquisition path analysis formally. A comparison between AP and nonAP states

    International Nuclear Information System (INIS)

    Listner, Clemens; Canty, Morton J.; Niemeyer, Irmgard; Rezniczek, Arnold; Stein, Gotthard

    2014-01-01

    In the past, the IAEA has planned its activities mainly based on the presence of nuclear material. However, resources should be spent where they are needed most. Therefore, a new risk model was developed to change the inspection system to a comprehensive, objective‑driven approach where the State is considered as a whole, the so called State‑level concept (SLC). Acquisition path analysis (APA) is a key element of the State‑level concept. By considering the State’s nuclear profile, the APA generates a list of acquisition paths ranked by their attractiveness for the State. Currently, this process is mainly based on expert judgment. However, the IAEA’s requirements state that APA must be objective, reproducible, transparent, standardized, documented and as a result non‑discriminatory. A formal approach fulfilling the requirements was set up by the authors in the past [1]. This methodology is based on a three step approach. The process starts in the first step with the parametrization of the network. In the second step, the network is analyzed in order find all acquisition paths for a State. Finally, game theory is used in the third step to model the decisions made by the IAEA and the State. In this paper, an advanced methodology will be presented. Improvements were made in the interface definition between the three stages. Also, the general network model was updated and the automatic visualization of acquisition paths was accomplished. Furthermore, a prototype implementation will be shown. The advanced methodology was applied to two test non‑nuclear weapon States under comprehensive safeguards agreements with the IAEA. Both States hold complex fuel cycles with only small technical differences. However,only one State is supposed to have the additional protocol (AP) in force. The example will show how the presence of the AP influences the detection probabilities of illegal behavior. As a consequence, these examples also indicate where to best focus

  10. Zero-Slack, Noncritical Paths

    Science.gov (United States)

    Simons, Jacob V., Jr.

    2017-01-01

    The critical path method/program evaluation and review technique method of project scheduling is based on the importance of managing a project's critical path(s). Although a critical path is the longest path through a network, its location in large projects is facilitated by the computation of activity slack. However, logical fallacies in…

  11. An improved and explicit surrogate variable analysis procedure by coefficient adjustment.

    Science.gov (United States)

    Lee, Seunggeun; Sun, Wei; Wright, Fred A; Zou, Fei

    2017-06-01

    Unobserved environmental, demographic, and technical factors can negatively affect the estimation and testing of the effects of primary variables. Surrogate variable analysis, proposed to tackle this problem, has been widely used in genomic studies. To estimate hidden factors that are correlated with the primary variables, surrogate variable analysis performs principal component analysis either on a subset of features or on all features, but weighting each differently. However, existing approaches may fail to identify hidden factors that are strongly correlated with the primary variables, and the extra step of feature selection and weight calculation makes the theoretical investigation of surrogate variable analysis challenging. In this paper, we propose an improved surrogate variable analysis using all measured features that has a natural connection with restricted least squares, which allows us to study its theoretical properties. Simulation studies and real data analysis show that the method is competitive to state-of-the-art methods.

  12. Power calculator for instrumental variable analysis in pharmacoepidemiology.

    Science.gov (United States)

    Walker, Venexia M; Davies, Neil M; Windmeijer, Frank; Burgess, Stephen; Martin, Richard M

    2017-10-01

    Instrumental variable analysis, for example with physicians' prescribing preferences as an instrument for medications issued in primary care, is an increasingly popular method in the field of pharmacoepidemiology. Existing power calculators for studies using instrumental variable analysis, such as Mendelian randomization power calculators, do not allow for the structure of research questions in this field. This is because the analysis in pharmacoepidemiology will typically have stronger instruments and detect larger causal effects than in other fields. Consequently, there is a need for dedicated power calculators for pharmacoepidemiological research. The formula for calculating the power of a study using instrumental variable analysis in the context of pharmacoepidemiology is derived before being validated by a simulation study. The formula is applicable for studies using a single binary instrument to analyse the causal effect of a binary exposure on a continuous outcome. An online calculator, as well as packages in both R and Stata, are provided for the implementation of the formula by others. The statistical power of instrumental variable analysis in pharmacoepidemiological studies to detect a clinically meaningful treatment effect is an important consideration. Research questions in this field have distinct structures that must be accounted for when calculating power. The formula presented differs from existing instrumental variable power formulae due to its parametrization, which is designed specifically for ease of use by pharmacoepidemiologists. © The Author 2017. Published by Oxford University Press on behalf of the International Epidemiological Association

  13. Which coordinate system for modelling path integration?

    Science.gov (United States)

    Vickerstaff, Robert J; Cheung, Allen

    2010-03-21

    Path integration is a navigation strategy widely observed in nature where an animal maintains a running estimate, called the home vector, of its location during an excursion. Evidence suggests it is both ancient and ubiquitous in nature, and has been studied for over a century. In that time, canonical and neural network models have flourished, based on a wide range of assumptions, justifications and supporting data. Despite the importance of the phenomenon, consensus and unifying principles appear lacking. A fundamental issue is the neural representation of space needed for biological path integration. This paper presents a scheme to classify path integration systems on the basis of the way the home vector records and updates the spatial relationship between the animal and its home location. Four extended classes of coordinate systems are used to unify and review both canonical and neural network models of path integration, from the arthropod and mammalian literature. This scheme demonstrates analytical equivalence between models which may otherwise appear unrelated, and distinguishes between models which may superficially appear similar. A thorough analysis is carried out of the equational forms of important facets of path integration including updating, steering, searching and systematic errors, using each of the four coordinate systems. The type of available directional cue, namely allothetic or idiothetic, is also considered. It is shown that on balance, the class of home vectors which includes the geocentric Cartesian coordinate system, appears to be the most robust for biological systems. A key conclusion is that deducing computational structure from behavioural data alone will be difficult or impossible, at least in the absence of an analysis of random errors. Consequently it is likely that further theoretical insights into path integration will require an in-depth study of the effect of noise on the four classes of home vectors. Copyright 2009 Elsevier Ltd

  14. Path Coefficient Analysis of Buffalo Production in Buldana District of Maharashtra

    Directory of Open Access Journals (Sweden)

    K U Bidwe

    2009-06-01

    Full Text Available A study entitled “Decomposition analysis of buffalo production in Buldana District was undertaken to ascertain the technological changes in term of breeding, feeding, housing, milking and calf management practices of buffalo. The path coefficient analysis of this study clearly demonstrated that daily milk production in buffaloes was influenced substantially by a single factor i.e management index. A combination of all the management practices in the form of overall management status on the rearing were responsible to influence the daily milk yield. However, rearing of good potential animals, feeding of sufficient amounts of dry and green fodder with required amount of concentrates to fulfill the nutritional requirements could favour the milk production in buffaloes. All these factors exhibited positive direct effect on milk production. The indirect effects were also found in positive direction, resulting a positive significant correlation for these factors. [Vet. World 2009; 2(3.000: 103-104

  15. Intrinsic movement variability at work. How long is the path from motor control to design engineering?

    Science.gov (United States)

    Gaudez, C; Gilles, M A; Savin, J

    2016-03-01

    For several years, increasing numbers of studies have highlighted the existence of movement variability. Before that, it was neglected in movement analysis and it is still almost completely ignored in workstation design. This article reviews motor control theories and factors influencing movement execution, and indicates how intrinsic movement variability is part of task completion. These background clarifications should help ergonomists and workstation designers to gain a better understanding of these concepts, which can then be used to improve design tools. We also question which techniques--kinematics, kinetics or muscular activity--and descriptors are most appropriate for describing intrinsic movement variability and for integration into design tools. By this way, simulations generated by designers for workstation design should be closer to the real movements performed by workers. This review emphasises the complexity of identifying, describing and processing intrinsic movement variability in occupational activities. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  16. Survey of Robot 3D Path Planning Algorithms

    Directory of Open Access Journals (Sweden)

    Liang Yang

    2016-01-01

    Full Text Available Robot 3D (three-dimension path planning targets for finding an optimal and collision-free path in a 3D workspace while taking into account kinematic constraints (including geometric, physical, and temporal constraints. The purpose of path planning, unlike motion planning which must be taken into consideration of dynamics, is to find a kinematically optimal path with the least time as well as model the environment completely. We discuss the fundamentals of these most successful robot 3D path planning algorithms which have been developed in recent years and concentrate on universally applicable algorithms which can be implemented in aerial robots, ground robots, and underwater robots. This paper classifies all the methods into five categories based on their exploring mechanisms and proposes a category, called multifusion based algorithms. For all these algorithms, they are analyzed from a time efficiency and implementable area perspective. Furthermore a comprehensive applicable analysis for each kind of method is presented after considering their merits and weaknesses.

  17. Path Creation, Path Dependence and Breaking Away from the Path: Re-Examining the Case of Nokia

    OpenAIRE

    Wang, Jens; Hedman, Jonas; Tuunainen, Virpi Kristiina

    2016-01-01

    The explanation of how and why firms succeed or fail is a recurrent research challenge. This is particularly important in the context of technological innovations. We focus on the role of historical events and decisions in explaining such success and failure. Using a case study of Nokia, we develop and extend a multi-layer path dependence framework. We identify four layers of path dependence: technical, strategic and leadership, organizational, and external collaboration. We show how path dep...

  18. Path-dependent functions

    International Nuclear Information System (INIS)

    Khrapko, R.I.

    1985-01-01

    A uniform description of various path-dependent functions is presented with the help of expansion of the type of the Taylor series. So called ''path-integrals'' and ''path-tensor'' are introduced which are systems of many-component quantities whose values are defined for arbitrary paths in coordinated region of space in such a way that they contain a complete information on the path. These constructions are considered as elementary path-dependent functions and are used instead of power monomials in the usual Taylor series. Coefficients of such an expansion are interpreted as partial derivatives dependent on the order of the differentiations or else as nonstandard cavariant derivatives called two-point derivatives. Some examples of pathdependent functions are presented.Space curvature tensor is considered whose geometrica properties are determined by the (non-transitive) translator of parallel transport of a general type. Covariant operation leading to the ''extension'' of tensor fiels is pointed out

  19. Robot path planning using expert systems and machine vision

    Science.gov (United States)

    Malone, Denis E.; Friedrich, Werner E.

    1992-02-01

    This paper describes a system developed for the robotic processing of naturally variable products. In order to plan the robot motion path it was necessary to use a sensor system, in this case a machine vision system, to observe the variations occurring in workpieces and interpret this with a knowledge based expert system. The knowledge base was acquired by carrying out an in-depth study of the product using examination procedures not available in the robotic workplace and relates the nature of the required path to the information obtainable from the machine vision system. The practical application of this system to the processing of fish fillets is described and used to illustrate the techniques.

  20. Review and classification of variability analysis techniques with clinical applications

    Science.gov (United States)

    2011-01-01

    Analysis of patterns of variation of time-series, termed variability analysis, represents a rapidly evolving discipline with increasing applications in different fields of science. In medicine and in particular critical care, efforts have focussed on evaluating the clinical utility of variability. However, the growth and complexity of techniques applicable to this field have made interpretation and understanding of variability more challenging. Our objective is to provide an updated review of variability analysis techniques suitable for clinical applications. We review more than 70 variability techniques, providing for each technique a brief description of the underlying theory and assumptions, together with a summary of clinical applications. We propose a revised classification for the domains of variability techniques, which include statistical, geometric, energetic, informational, and invariant. We discuss the process of calculation, often necessitating a mathematical transform of the time-series. Our aims are to summarize a broad literature, promote a shared vocabulary that would improve the exchange of ideas, and the analyses of the results between different studies. We conclude with challenges for the evolving science of variability analysis. PMID:21985357

  1. Review and classification of variability analysis techniques with clinical applications.

    Science.gov (United States)

    Bravi, Andrea; Longtin, André; Seely, Andrew J E

    2011-10-10

    Analysis of patterns of variation of time-series, termed variability analysis, represents a rapidly evolving discipline with increasing applications in different fields of science. In medicine and in particular critical care, efforts have focussed on evaluating the clinical utility of variability. However, the growth and complexity of techniques applicable to this field have made interpretation and understanding of variability more challenging. Our objective is to provide an updated review of variability analysis techniques suitable for clinical applications. We review more than 70 variability techniques, providing for each technique a brief description of the underlying theory and assumptions, together with a summary of clinical applications. We propose a revised classification for the domains of variability techniques, which include statistical, geometric, energetic, informational, and invariant. We discuss the process of calculation, often necessitating a mathematical transform of the time-series. Our aims are to summarize a broad literature, promote a shared vocabulary that would improve the exchange of ideas, and the analyses of the results between different studies. We conclude with challenges for the evolving science of variability analysis.

  2. comparative analysis of path loss prediction models for urban

    African Journals Online (AJOL)

    the acceptable minimum MSE value of 6dB for good signal propagation. Keywords: macrocellular areas ... itate high-speed data communications in ad- dition to voice calls. ... On the basis of the mobile radio environment, path loss predic-.

  3. Air Pollution alongside Bike-Paths in Bogota - Colombia

    Directory of Open Access Journals (Sweden)

    Juan Felipe Franco

    2016-11-01

    Full Text Available The study we present in this paper aims at characterizing the range of fine particulate matter (PM2.5 and black carbon (BC concentrations to which bike-path users in Bogotá are exposed to. Using a bike equipped with a DustTrak and a micro-aethalometer we measured PM2.5 and BC concentration levels along bike-paths corridors, during weekdays and weekends. Experiments were conducted in fours streets, representing four typical configurations of bike-paths in the city. Traffic data for workdays was also available from local mobility authority. Results indicate that bike-paths users in Bogota are exposed to air pollution levels far exceeding the threshold values established as potentially dangerous for human health. Average concentrations for PM2.5 ranged between 80 and 136 ug/m3 in workdays and between 30 and 72 ug/m3 in weekends. BC mean concentrations were between 16 and 38 µg/m3 during workdays and in the range 10 to 32 µg/m3 during weekends. A statistically significant difference exists in the levels of pollutants concentrations measured during workdays and weekends for all the considered bike paths. According to our results, both traffic volume and diffusions conditions, which are affected by many factors including street geometry, affect bike-path user’s exposure levels. Taking into account the important role that bicycling is playing as an alternative transport mode in Latin American cities, we consider these results provide useful insights to increase the appreciation of the excessive bikers´ exposure to air pollution in Bogotá. Moreover, these findings contribute with technical elements that should lead to the inclusion of air quality variable when designing and planning sustainable urban mobility infrastructures.

  4. A novel algorithm for solving optimal path planning problems based on parametrization method and fuzzy aggregation

    International Nuclear Information System (INIS)

    Zamirian, M.; Kamyad, A.V.; Farahi, M.H.

    2009-01-01

    In this Letter a new approach for solving optimal path planning problems for a single rigid and free moving object in a two and three dimensional space in the presence of stationary or moving obstacles is presented. In this approach the path planning problems have some incompatible objectives such as the length of path that must be minimized, the distance between the path and obstacles that must be maximized and etc., then a multi-objective dynamic optimization problem (MODOP) is achieved. Considering the imprecise nature of decision maker's (DM) judgment, these multiple objectives are viewed as fuzzy variables. By determining intervals for the values of these fuzzy variables, flexible monotonic decreasing or increasing membership functions are determined as the degrees of satisfaction of these fuzzy variables on their intervals. Then, the optimal path planning policy is searched by maximizing the aggregated fuzzy decision values, resulting in a fuzzy multi-objective dynamic optimization problem (FMODOP). Using a suitable t-norm, the FMODOP is converted into a non-linear dynamic optimization problem (NLDOP). By using parametrization method and some calculations, the NLDOP is converted into the sequence of conventional non-linear programming problems (NLPP). It is proved that the solution of this sequence of the NLPPs tends to a Pareto optimal solution which, among other Pareto optimal solutions, has the best satisfaction of DM for the MODOP. Finally, the above procedure as a novel algorithm integrating parametrization method and fuzzy aggregation to solve the MODOP is proposed. Efficiency of our approach is confirmed by some numerical examples.

  5. Direct and indirect effects of climatic variations on the interannual variability in net ecosystem exchange across terrestrial ecosystems

    Directory of Open Access Journals (Sweden)

    Junjiong Shao

    2016-08-01

    Full Text Available Climatic variables not only directly affect the interannual variability (IAV in net ecosystem exchange of CO2 (NEE but also indirectly drive it by changing the physiological parameters. Identifying these direct and indirect paths can reveal the underlying mechanisms of carbon (C dynamics. In this study, we applied a path analysis using flux data from 65 sites to quantify the direct and indirect climatic effects on IAV in NEE and to evaluate the potential relationships among the climatic variables and physiological parameters that represent physiology and phenology of ecosystems. We found that the maximum photosynthetic rate was the most important factor for the IAV in gross primary productivity (GPP, which was mainly induced by the variation in vapour pressure deficit. For ecosystem respiration (RE, the most important drivers were GPP and the reference respiratory rate. The biome type regulated the direct and indirect paths, with distinctive differences between forests and non-forests, evergreen needleleaf forests and deciduous broadleaf forests, and between grasslands and croplands. Different paths were also found among wet, moist and dry ecosystems. However, the climatic variables can only partly explain the IAV in physiological parameters, suggesting that the latter may also result from other biotic and disturbance factors. In addition, the climatic variables related to NEE were not necessarily the same as those related to GPP and RE, indicating the emerging difficulty encountered when studying the IAV in NEE. Overall, our results highlight the contribution of certain physiological parameters to the IAV in C fluxes and the importance of biome type and multi-year water conditions, which should receive more attention in future experimental and modelling research.

  6. Patterns and singular features of extreme fluctuational paths of a periodically driven system

    International Nuclear Information System (INIS)

    Chen, Zhen; Liu, Xianbin

    2016-01-01

    Large fluctuations of an overdamped periodically driven oscillating system are investigated theoretically and numerically in the limit of weak noise. Optimal paths fluctuating to certain point are given by statistical analysis using the concept of prehistory probability distribution. The validity of statistical results is verified by solutions of boundary value problem. Optimal paths are found to change topologically when terminating points lie at opposite side of a switching line. Patterns of extreme paths are plotted through a proper parameterization of Lagrangian manifold having complicated structures. Several extreme paths to the same point are obtained by multiple solutions of boundary value solutions. Actions along various extreme paths are calculated and associated analysis is performed in relation to the singular features of the patterns. - Highlights: • Both extreme and optimal paths are obtained by various methods. • Boundary value problems are solved to ensure the validity of statistical results. • Topological structure of Lagrangian manifold is considered. • Singularities of the pattern of extreme paths are studied.

  7. Diversion Path Analysis handbook. Volume 4 (of 4 volumes). Computer Program 2

    International Nuclear Information System (INIS)

    Schleter, J.C.

    1978-11-01

    The FORTRAN IV computer program, DPA Computer Program 2 (DPACP-2) is used to produce tables and statistics on modifications identified when performing a Diversion Path Analysis (DPA) in accord with the methodology given in Volume 1. The program requires 259088 bytes exclusive of the operating system. The data assembled and tabulated by DPACP-2 assist the DPA team in analyzing and evaluating modifications to the plant's safeguards system that would eliminate, or reduce the severity of, vulnerabilities identified by means of the DPA. These vulnerabilities relate to the capability of the plant's material control and material accounting subsystems to indicate diversion of special nuclear material (SNM) by a knowledgeable insider

  8. Factors That Affect Suicidal Attempt Risk Among Korean Elderly Adults: A Path Analysis

    Directory of Open Access Journals (Sweden)

    Junsoo Ro

    2015-01-01

    Full Text Available Objectives: Among the Korean elderly (those 65 years of age and older, the suicide rate is 80.3/100 000 people, which is ten times higher than the Organization for Economic Cooperation and Development average. Because South Korea is rapidly becoming an aging population, this high elderly suicidal rate will only get worse. Although the size of the elderly suicide problem is quite large, previous research in South Korea has surveyed restricted areas and not the entire country. Even though the factors that affect elderly suicide are complicated, there has been little research into these influencing factors. Thus, this research uses the national survey data (Community Health Survey that was obtained in 2009. Additionally, we analyze factors affecting elderly suicidal ideation and attempts as well as the paths of these effects. Methods: Community Health Survey data obtained by the Korea Centers for Disease Control and Prevention in 2009 was used for this study. We additionally examined the factors that affect suicide with chi-squared tests, t-tests, Pearson’s correlation test, and path analysis. Results: Depressive symptoms and suicidal ideation are the only factors that directly affect suicidal attempts. Demographic, behavioral, and physical activity factors have indirect effects on suicidal attempts. Conclusions: Depression has the strongest influence on suicidal ideation and attempts. Demographic, behavioral, and physical activity factors affect suicidal attempts mostly through depressive symptoms. In addition, there is a path that suggests that demographic, behavioral, and physical activity factors affect suicidal attempts not through depression symptoms but only through suicidal ideation. This means that the elderly who do not have depression symptoms attempt suicide according to their own situations and characteristics.

  9. Progression paths in children's problem solving: The influence of dynamic testing, initial variability, and working memory.

    Science.gov (United States)

    Resing, Wilma C M; Bakker, Merel; Pronk, Christine M E; Elliott, Julian G

    2017-01-01

    The current study investigated developmental trajectories of analogical reasoning performance of 104 7- and 8-year-old children. We employed a microgenetic research method and multilevel analysis to examine the influence of several background variables and experimental treatment on the children's developmental trajectories. Our participants were divided into two treatment groups: repeated practice alone and repeated practice with training. Each child received an initial working memory assessment and was subsequently asked to solve figural analogies on each of several sessions. We examined children's analogical problem-solving behavior and their subsequent verbal accounts of their employed solving processes. We also investigated the influence of verbal and visual-spatial working memory capacity and initial variability in strategy use on analogical reasoning development. Results indicated that children in both treatment groups improved but that gains were greater for those who had received training. Training also reduced the influence of children's initial variability in the use of analogical strategies with the degree of improvement in reasoning largely unrelated to working memory capacity. Findings from this study demonstrate the value of a microgenetic research method and the use of multilevel analysis to examine inter- and intra-individual change in problem-solving processes. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Prediction of slant path rain attenuation statistics at various locations

    Science.gov (United States)

    Goldhirsh, J.

    1977-01-01

    The paper describes a method for predicting slant path attenuation statistics at arbitrary locations for variable frequencies and path elevation angles. The method involves the use of median reflectivity factor-height profiles measured with radar as well as the use of long-term point rain rate data and assumed or measured drop size distributions. The attenuation coefficient due to cloud liquid water in the presence of rain is also considered. Absolute probability fade distributions are compared for eight cases: Maryland (15 GHz), Texas (30 GHz), Slough, England (19 and 37 GHz), Fayetteville, North Carolina (13 and 18 GHz), and Cambridge, Massachusetts (13 and 18 GHz).

  11. STRATEGIC INFORMATION SYSTEMS PLANNING IN THE BANKING SECTOR—A PATH ANALYTIC MODEL STUDY IN THE INDIAN CONTEXT

    Directory of Open Access Journals (Sweden)

    A. M. Rawani

    2002-01-01

    Full Text Available This paper presents a path analytic model showing the cause and effect relationships among various Information Systems (IS planning variables for the banking sector in India. In recent years, there has been an increased awareness among banks of the potential of Information Technology (IT and the use of information systems. Strategic information system planning (SISP becomes an important issue in the use of IS strategically. In India, banks have now started realizing the importance of SISP. In this study, 11 IS planning variables for the banking sector in India are examined and the influence of one over the other is investigated using path analysis. Data for the study are collected from 52 banks operating in India. The results of the study indicate that top management involvement in IS planning greatly influences the whole planning exercise. Moreover, top management involvement is higher when they foresee greater future impact of IS. The study also highlights the need and importance of user training in the banking sector. Change in the focus and orientation of user-training will make the users competent to conceive with innovative IS applications.

  12. A multi-regional structural path analysis of the energy supply chain in China's construction industry

    International Nuclear Information System (INIS)

    Hong, Jingke; Shen, Qiping; Xue, Fan

    2016-01-01

    The construction industry in China exerts significant environmental impacts and uses considerable resources because of rapid urbanization. This study conducted a structural path analysis (SPA) based on the multi-regional input–output table to quantify environmental impact transmission in the entire supply chain. Results indicated that the direct resource input (the first stage) along with on-site construction (the zeroth stage) consumed the highest amount of energy in the supply chain and accounted for approximately 50% of total energy consumption. Regional analysis showed that energy consumption in the construction industry at the provincial level was self-sufficient. Sectoral analysis demonstrated that the direct inputs from the sectors of “manufacture of non-metallic mineral products” and “smelting and pressing of metals” generated the most important energy flows, whereas the sectors of “production and distribution of electric power and heat power” and “extraction of petroleum and natural gas” significantly but indirectly influenced energy use. Sensitivity analysis exhibited that the system boundary of SPA could be narrowed down into the first two upstream stages that contained nearly 50% of energy flow information or expanded toward the first five upstream stages that represented 80% of total energy consumption. - Highlights: •We designed an optimized algorithm for multi-regional SPA. •We extracted energy-intensive paths throughout the upstream supply chain. •We explored self-sufficiency characteristic for provincial construction industries. •We identified energy-intensive sectors hidden in higher-order supply chain. •We developed an effective strategy for narrowing down the system boundary of SPA.

  13. Generating feasible transition paths for testing from an extended finite state machine (EFSM) with the counter problem

    OpenAIRE

    Kalaji, AS; Hierons, RM; Swift, S

    2009-01-01

    The extended finite state machine (EFSM) is a powerful approach for modeling state-based systems. However, testing from EFSMs is complicated by the existence of infeasible paths. One important problem is the existence of a transition with a guard that references a counter variable whose value depends on previous transitions. The presence of such transitions in paths often leads to infeasible paths. This paper proposes a novel approach to bypass the counter problem. The proposed approach is ev...

  14. Rotational error in path integration: encoding and execution errors in angle reproduction.

    Science.gov (United States)

    Chrastil, Elizabeth R; Warren, William H

    2017-06-01

    Path integration is fundamental to human navigation. When a navigator leaves home on a complex outbound path, they are able to keep track of their approximate position and orientation and return to their starting location on a direct homebound path. However, there are several sources of error during path integration. Previous research has focused almost exclusively on encoding error-the error in registering the outbound path in memory. Here, we also consider execution error-the error in the response, such as turning and walking a homebound trajectory. In two experiments conducted in ambulatory virtual environments, we examined the contribution of execution error to the rotational component of path integration using angle reproduction tasks. In the reproduction tasks, participants rotated once and then rotated again to face the original direction, either reproducing the initial turn or turning through the supplementary angle. One outstanding difficulty in disentangling encoding and execution error during a typical angle reproduction task is that as the encoding angle increases, so does the required response angle. In Experiment 1, we dissociated these two variables by asking participants to report each encoding angle using two different responses: by turning to walk on a path parallel to the initial facing direction in the same (reproduction) or opposite (supplementary angle) direction. In Experiment 2, participants reported the encoding angle by turning both rightward and leftward onto a path parallel to the initial facing direction, over a larger range of angles. The results suggest that execution error, not encoding error, is the predominant source of error in angular path integration. These findings also imply that the path integrator uses an intrinsic (action-scaled) rather than an extrinsic (objective) metric.

  15. Intelligence, previous convictions and interrogative suggestibility: a path analysis of alleged false-confession cases.

    Science.gov (United States)

    Sharrock, R; Gudjonsson, G H

    1993-05-01

    The main purpose of this study was to investigate the relationship between interrogative suggestibility and previous convictions among 108 defendants in criminal trials, using a path analysis technique. It was hypothesized that previous convictions, which may provide defendants with interrogative experiences, would correlate negatively with 'shift' as measured by the Gudjonsson Suggestibility Scale (Gudjonsson, 1984a), after intelligence and memory had been controlled for. The hypothesis was partially confirmed and the theoretical and practical implications of the findings are discussed.

  16. Clinical Trials With Large Numbers of Variables: Important Advantages of Canonical Analysis.

    Science.gov (United States)

    Cleophas, Ton J

    2016-01-01

    Canonical analysis assesses the combined effects of a set of predictor variables on a set of outcome variables, but it is little used in clinical trials despite the omnipresence of multiple variables. The aim of this study was to assess the performance of canonical analysis as compared with traditional multivariate methods using multivariate analysis of covariance (MANCOVA). As an example, a simulated data file with 12 gene expression levels and 4 drug efficacy scores was used. The correlation coefficient between the 12 predictor and 4 outcome variables was 0.87 (P = 0.0001) meaning that 76% of the variability in the outcome variables was explained by the 12 covariates. Repeated testing after the removal of 5 unimportant predictor and 1 outcome variable produced virtually the same overall result. The MANCOVA identified identical unimportant variables, but it was unable to provide overall statistics. (1) Canonical analysis is remarkable, because it can handle many more variables than traditional multivariate methods such as MANCOVA can. (2) At the same time, it accounts for the relative importance of the separate variables, their interactions and differences in units. (3) Canonical analysis provides overall statistics of the effects of sets of variables, whereas traditional multivariate methods only provide the statistics of the separate variables. (4) Unlike other methods for combining the effects of multiple variables such as factor analysis/partial least squares, canonical analysis is scientifically entirely rigorous. (5) Limitations include that it is less flexible than factor analysis/partial least squares, because only 2 sets of variables are used and because multiple solutions instead of one is offered. We do hope that this article will stimulate clinical investigators to start using this remarkable method.

  17. Fast orthogonal transforms and generation of Brownian paths.

    Science.gov (United States)

    Leobacher, Gunther

    2012-04-01

    We present a number of fast constructions of discrete Brownian paths that can be used as alternatives to principal component analysis and Brownian bridge for stratified Monte Carlo and quasi-Monte Carlo. By fast we mean that a path of length [Formula: see text] can be generated in [Formula: see text] floating point operations. We highlight some of the connections between the different constructions and we provide some numerical examples.

  18. Path integral analysis of Jarzynski's equality: Analytical results

    Science.gov (United States)

    Minh, David D. L.; Adib, Artur B.

    2009-02-01

    We apply path integrals to study nonequilibrium work theorems in the context of Brownian dynamics, deriving in particular the equations of motion governing the most typical and most dominant trajectories. For the analytically soluble cases of a moving harmonic potential and a harmonic oscillator with a time-dependent natural frequency, we find such trajectories, evaluate the work-weighted propagators, and validate Jarzynski’s equality.

  19. Path coefficient analysis of zinc dynamics in varying soil environment

    International Nuclear Information System (INIS)

    Rattan, R.K.; Phung, C.V.; Singhal, S.K.; Deb, D.L.; Singh, A.K.

    1994-01-01

    Influence of soil properties on labile zinc, as measured by diethylene-triamine pentaacetic acid (DTPA) and zinc-65, and self-diffusion coefficients of zinc was assessed on 22 surface soil samples varying widely in their characteristics following linear regression and path coefficient analysis techniques. DTPA extractable zinc could be predicted from organic carbon status and pH of the soil with a highly significant coefficient of determination (R 2 =0.84 ** ). Ninety seven per cent variation in isotopically exchangeable zinc was explained by pH, clay content and cation exchange capacity (CEC) of soil. The self-diffusion coefficients (DaZn and DpZn) and buffer power of zinc exhibited exponential relationship with soil properties, pH being the most dominant one. Soil properties like organic matter, clay content etc. exhibited indirect effects on zinc diffusion rates via pH only. (author). 13 refs., 6 tabs

  20. A fast tomographic method for searching the minimum free energy path

    International Nuclear Information System (INIS)

    Chen, Changjun; Huang, Yanzhao; Xiao, Yi; Jiang, Xuewei

    2014-01-01

    Minimum Free Energy Path (MFEP) provides a lot of important information about the chemical reactions, like the free energy barrier, the location of the transition state, and the relative stability between reactant and product. With MFEP, one can study the mechanisms of the reaction in an efficient way. Due to a large number of degrees of freedom, searching the MFEP is a very time-consuming process. Here, we present a fast tomographic method to perform the search. Our approach first calculates the free energy surfaces in a sequence of hyperplanes perpendicular to a transition path. Based on an objective function and the free energy gradient, the transition path is optimized in the collective variable space iteratively. Applications of the present method to model systems show that our method is practical. It can be an alternative approach for finding the state-to-state MFEP

  1. WKB wave function for many-variable systems

    International Nuclear Information System (INIS)

    Sakita, B.; Tzani, R.

    1986-01-01

    The WKB method is a non-perturbative semi-classical method in quantum mechanics. The method for a system of one degree of freedom is well known and described in standard textbooks. The method for a system with many degrees of freedom especially for quantum fields is more involved. There exist two methods: Feynman path integral and Schrodinger wave function. The Feynman path integral WKB method is essentially a stationary phase approximation for Feynman path integrals. The WKB Schrodinger wave function method is on the other hand an extension of the standard WKB to many-variable systems

  2. An ab initio study on the transition paths from graphite to diamond under pressure

    International Nuclear Information System (INIS)

    Dong Xiao; Zhou Xiangfeng; Wang Huitian; Qian Guangrui; Zhao Zhisheng; Tian Yongjun

    2013-01-01

    We calculate and compare the transition paths from graphite to two types of diamond using the variable cell nudged elastic band method. For the phase transition from graphite to cubic diamond, we analyze in detail how the π bonds transit to the σ bonds in an electronic structure. Meanwhile, a new transition path with a lower energy barrier for the transformation from graphite to hexagonal diamond is discovered. The path has its own peculiar sp 2 –sp 3 bonding configurations, serving as a transition state. Further calculation suggests that the sp 2 –sp 3 transition state represents an expected general phenomenon for cold-compressed graphite. (paper)

  3. Path integral methods for the dynamics of stochastic and disordered systems

    DEFF Research Database (Denmark)

    Hertz, John A.; Roudi, Yasser; Sollich, Peter

    2017-01-01

    We review some of the techniques used to study the dynamics of disordered systems subject to both quenched and fast (thermal) noise. Starting from the Martin–Siggia–Rose/Janssen–De Dominicis–Peliti path integral formalism for a single variable stochastic dynamics, we provide a pedagogical survey...

  4. Uncertainty and Sensitivity Analysis for an Ibuprofen Synthesis Model Based on Hoechst Path

    DEFF Research Database (Denmark)

    da Conceicao Do Carmo Montes, Frederico; Gernaey, Krist V.; Sin, Gürkan

    2017-01-01

    into consideration the effects of temperature, acidity, and the choice of the catalyst. Parameter estimation and uncertainty analysis were conducted on the kinetic model parameters using experimental data available in the literature. Finally, one factor at a time sensitivity analysis in the form of deviations......The pharmaceutical industry faces several challenges and barriers when implementing new or improving current pharmaceutical processes, such as competition from generic drug manufacturers and stricter regulations from the U.S. Food and Drug Administration and the European Medicine agency. The demand...... for efficient and reliable models to simulate and design/improve pharmaceutical processes is therefore increasing. For the case of ibuprofen, a well-known anti-inflammatory drug, the existing models do not include its complete synthesis path, usually referring only to one out of aset of different reactions...

  5. Scalable conditional induction variables (CIV) analysis

    KAUST Repository

    Oancea, Cosmin E.

    2015-02-01

    Subscripts using induction variables that cannot be expressed as a formula in terms of the enclosing-loop indices appear in the low-level implementation of common programming abstractions such as Alter, or stack operations and pose significant challenges to automatic parallelization. Because the complexity of such induction variables is often due to their conditional evaluation across the iteration space of loops we name them Conditional Induction Variables (CIV). This paper presents a flow-sensitive technique that summarizes both such CIV-based and affine subscripts to program level, using the same representation. Our technique requires no modifications of our dependence tests, which is agnostic to the original shape of the subscripts, and is more powerful than previously reported dependence tests that rely on the pairwise disambiguation of read-write references. We have implemented the CIV analysis in our parallelizing compiler and evaluated its impact on five Fortran benchmarks. We have found that that there are many important loops using CIV subscripts and that our analysis can lead to their scalable parallelization. This in turn has led to the parallelization of the benchmark programs they appear in.

  6. Career Paths in Educational Leadership: Examining Principals' Narratives

    Science.gov (United States)

    Parylo, Oksana; Zepeda, Sally J.; Bengtson, Ed

    2012-01-01

    This qualitative study analyzes the career path narratives of active principals. Structural narrative analysis was supplemented with sociolinguistic theory and thematic narrative analysis to discern the similarities and differences, as well as the patterns in the language used by participating principals. Thematic analysis found four major themes…

  7. The XRF spectrometer and the selection of analysis conditions (instrumental variables)

    International Nuclear Information System (INIS)

    Willis, J.P.

    2002-01-01

    Full text: This presentation will begin with a brief discussion of EDXRF and flat- and curved-crystal WDXRF spectrometers, contrasting the major differences between the three types. The remainder of the presentation will contain a detailed overview of the choice and settings of the many instrumental variables contained in a modern WDXRF spectrometer, and will discuss critically the choices facing the analyst in setting up a WDXRF spectrometer for different elements and applications. In particular it will discuss the choice of tube target (when a choice is possible), the kV and mA settings, tube filters, collimator masks, collimators, analyzing crystals, secondary collimators, detectors, pulse height selection, X-ray path medium (air, nitrogen, vacuum or helium), counting times for peak and background positions and their effect on counting statistics and lower limit of detection (LLD). The use of Figure of Merit (FOM) calculations to objectively choose the best combination of instrumental variables also will be discussed. This presentation will be followed by a shorter session on a subsequent day entitled - A Selection of XRF Conditions - Practical Session, where participants will be given the opportunity to discuss in groups the selection of the best instrumental variables for three very diverse applications. Copyright (2002) Australian X-ray Analytical Association Inc

  8. Multi-AGV path planning with double-path constraints by using an improved genetic algorithm.

    Directory of Open Access Journals (Sweden)

    Zengliang Han

    Full Text Available This paper investigates an improved genetic algorithm on multiple automated guided vehicle (multi-AGV path planning. The innovations embody in two aspects. First, three-exchange crossover heuristic operators are used to produce more optimal offsprings for getting more information than with the traditional two-exchange crossover heuristic operators in the improved genetic algorithm. Second, double-path constraints of both minimizing the total path distance of all AGVs and minimizing single path distances of each AGV are exerted, gaining the optimal shortest total path distance. The simulation results show that the total path distance of all AGVs and the longest single AGV path distance are shortened by using the improved genetic algorithm.

  9. Leak-Path Factor Analysis for the Nuclear Materials Storage Facility

    International Nuclear Information System (INIS)

    Shaffer, C.; Leonard, M.

    1999-01-01

    Leak-path factors (LPFs) were calculated for the Nuclear Materials Storage Facility (NMSF) located in the Plutonium Facility, Building 41 at the Los Alamos National Laboratory Technical Area 55. In the unlikely event of an accidental fire powerful enough to fail a container holding actinides, the subsequent release of oxides, modeled as PuO 2 aerosols, from the facility and into the surrounding environment was predicted. A 1-h nondestructive assay (NDA) laboratory fire accident was simulated with the MELCOR severe accident analysis code. Fire-driven air movement along with wind-driven air infiltration transported a portion of these actinides from the building. This fraction is referred to as the leak-path factor. The potential effect of smoke aerosol on the transport of the actinides was investigated to verify the validity of neglecting the smoke as conservative. The input model for the NMSF consisted of a system of control volumes, flow pathways, and surfaces sufficient to model the thermal-hydraulic conditions within the facility and the aerosol transport data necessary to simulate the transport of PuO 2 particles. The thermal-hydraulic, heat-transfer, and aerosol-transport models are solved simultaneously with data being exchanged between models. A MELCOR input model was designed such that it would reproduce the salient features of the fire per the corresponding CFAST calculation. Air infiltration into and out of the facility would be affected strongly by wind-driven differential pressures across the building. Therefore, differential pressures were applied to each side of the building according to guidance found in the ASHRAE handbook using a standard-velocity head equation with a leading multiplier to account for the orientation of the wind with the building. The model for the transport of aerosols considered all applicable transport processes, but the deposition within the building clearly was dominated by gravitational settling

  10. Differential neural network configuration during human path integration

    Science.gov (United States)

    Arnold, Aiden E. G. F; Burles, Ford; Bray, Signe; Levy, Richard M.; Iaria, Giuseppe

    2014-01-01

    Path integration is a fundamental skill for navigation in both humans and animals. Despite recent advances in unraveling the neural basis of path integration in animal models, relatively little is known about how path integration operates at a neural level in humans. Previous attempts to characterize the neural mechanisms used by humans to visually path integrate have suggested a central role of the hippocampus in allowing accurate performance, broadly resembling results from animal data. However, in recent years both the central role of the hippocampus and the perspective that animals and humans share similar neural mechanisms for path integration has come into question. The present study uses a data driven analysis to investigate the neural systems engaged during visual path integration in humans, allowing for an unbiased estimate of neural activity across the entire brain. Our results suggest that humans employ common task control, attention and spatial working memory systems across a frontoparietal network during path integration. However, individuals differed in how these systems are configured into functional networks. High performing individuals were found to more broadly express spatial working memory systems in prefrontal cortex, while low performing individuals engaged an allocentric memory system based primarily in the medial occipito-temporal region. These findings suggest that visual path integration in humans over short distances can operate through a spatial working memory system engaging primarily the prefrontal cortex and that the differential configuration of memory systems recruited by task control networks may help explain individual biases in spatial learning strategies. PMID:24808849

  11. A Method of Forming the Optimal Set of Disjoint Path in Computer Networks

    Directory of Open Access Journals (Sweden)

    As'ad Mahmoud As'ad ALNASER

    2017-04-01

    Full Text Available This work provides a short analysis of algorithms of multipath routing. The modified algorithm of formation of the maximum set of not crossed paths taking into account their metrics is offered. Optimization of paths is carried out due to their reconfiguration with adjacent deadlock path. Reconfigurations are realized within the subgraphs including only peaks of the main and an adjacent deadlock path. It allows to reduce the field of formation of an optimum path and time complexity of its formation.

  12. Calculating Graph Algorithms for Dominance and Shortest Path

    DEFF Research Database (Denmark)

    Sergey, Ilya; Midtgaard, Jan; Clarke, Dave

    2012-01-01

    We calculate two iterative, polynomial-time graph algorithms from the literature: a dominance algorithm and an algorithm for the single-source shortest path problem. Both algorithms are calculated directly from the definition of the properties by fixed-point fusion of (1) a least fixed point...... expressing all finite paths through a directed graph and (2) Galois connections that capture dominance and path length. The approach illustrates that reasoning in the style of fixed-point calculus extends gracefully to the domain of graph algorithms. We thereby bridge common practice from the school...... of program calculation with common practice from the school of static program analysis, and build a novel view on iterative graph algorithms as instances of abstract interpretation...

  13. Integral transforms of the quantum mechanical path integral: Hit function and path-averaged potential

    Science.gov (United States)

    Edwards, James P.; Gerber, Urs; Schubert, Christian; Trejo, Maria Anabel; Weber, Axel

    2018-04-01

    We introduce two integral transforms of the quantum mechanical transition kernel that represent physical information about the path integral. These transforms can be interpreted as probability distributions on particle trajectories measuring respectively the relative contribution to the path integral from paths crossing a given spatial point (the hit function) and the likelihood of values of the line integral of the potential along a path in the ensemble (the path-averaged potential).

  14. Preregularization and the path integral approach to the chiral anomaly

    International Nuclear Information System (INIS)

    Elias, V.; McKeon, G.; Steele, T.; Mann, R.B.; Treml, T.F.; Sherry, T.N.

    1987-01-01

    We explore the connection between perturbative and non-perturbative (path-integral) approaches to the axial anomaly. In particular, we show how the Jacobian associated with the fermionic measure corresponding to local axial transformations may be calculated directly from shift-of-integration-variable surface terms in four Euclidean dimensions. No regularization (explicit parametrization of UV infinities) is required in this approach, but invariance of the Jacobian under vector gauge transformations (i.e. preregularization) is required to remove a variable-of-integration ambiguity within the expression for the Jacobian of the fermionic measure. (orig.)

  15. Calculation of quantum-mechanical system energy spectra using path integrals

    International Nuclear Information System (INIS)

    Evseev, A.M.; Dmitriev, V.P.

    1977-01-01

    A solution of the Feynman quantum-mechanical integral connecting a wave function (psi (x, t)) at a moment t+tau (tau → 0) with the wave function at the moment t is provided by complex variable substitution and subsequent path integration. Time dependence of the wave function is calculated by the Monte Carlo method. The Fourier inverse transformation of the wave function by path integration calculated has been applied to determine the energy spectra. Energy spectra are presented of a hydrogen atom derived from wave function psi (x, t) at different x, as well as boson energy spectra of He, Li, and Be atoms obtained from psi (x, t) at X = O

  16. Completely automated open-path FT-IR spectrometry.

    Science.gov (United States)

    Griffiths, Peter R; Shao, Limin; Leytem, April B

    2009-01-01

    Atmospheric analysis by open-path Fourier-transform infrared (OP/FT-IR) spectrometry has been possible for over two decades but has not been widely used because of the limitations of the software of commercial instruments. In this paper, we describe the current state-of-the-art of the hardware and software that constitutes a contemporary OP/FT-IR spectrometer. We then describe advances that have been made in our laboratory that have enabled many of the limitations of this type of instrument to be overcome. These include not having to acquire a single-beam background spectrum that compensates for absorption features in the spectra of atmospheric water vapor and carbon dioxide. Instead, an easily measured "short path-length" background spectrum is used for calculation of each absorbance spectrum that is measured over a long path-length. To accomplish this goal, the algorithm used to calculate the concentrations of trace atmospheric molecules was changed from classical least-squares regression (CLS) to partial least-squares regression (PLS). For calibration, OP/FT-IR spectra are measured in pristine air over a wide variety of path-lengths, temperatures, and humidities, ratioed against a short-path background, and converted to absorbance; the reference spectrum of each analyte is then multiplied by randomly selected coefficients and added to these background spectra. Automatic baseline correction for small molecules with resolved rotational fine structure, such as ammonia and methane, is effected using wavelet transforms. A novel method of correcting for the effect of the nonlinear response of mercury cadmium telluride detectors is also incorporated. Finally, target factor analysis may be used to detect the onset of a given pollutant when its concentration exceeds a certain threshold. In this way, the concentration of atmospheric species has been obtained from OP/FT-IR spectra measured at intervals of 1 min over a period of many hours with no operator intervention.

  17. Robust cluster analysis and variable selection

    CERN Document Server

    Ritter, Gunter

    2014-01-01

    Clustering remains a vibrant area of research in statistics. Although there are many books on this topic, there are relatively few that are well founded in the theoretical aspects. In Robust Cluster Analysis and Variable Selection, Gunter Ritter presents an overview of the theory and applications of probabilistic clustering and variable selection, synthesizing the key research results of the last 50 years. The author focuses on the robust clustering methods he found to be the most useful on simulated data and real-time applications. The book provides clear guidance for the varying needs of bot

  18. [Quantitative analysis of drug expenditures variability in dermatology units].

    Science.gov (United States)

    Moreno-Ramírez, David; Ferrándiz, Lara; Ramírez-Soto, Gabriel; Muñoyerro, M Dolores

    2013-01-01

    Variability in adjusted drug expenditures among clinical departments raises the possibility of difficult access to certain therapies at the time that avoidable expenditures may also exist. Nevertheless, drug expenditures are not usually applied to clinical practice variability analysis. To identify and quantify variability in drug expenditures in comparable dermatology department of the Servicio Andaluz de Salud. Comparative economic analysis regarding the drug expenditures adjusted to population and health care production in 18 dermatology departments of the Servicio Andaluz de Salud. The 2012 cost and production data (homogeneous production units -HPU-)were provided by Inforcoan, the cost accounting information system of the Servicio Andaluz de Salud. The observed drug expenditure ratio ranged from 0.97?/inh to 8.90?/inh and from 208.45?/HPU to 1,471.95?/ HPU. The Pearson correlation between drug expenditure and population was 0.25 and 0.35 for the correlation between expenditure and homogeneous production (p=0.32 and p=0,15, respectively), both Pearson coefficients confirming the lack of correlation and arelevant degree of variability in drug expenditures. The quantitative analysis of variability performed through Pearson correlation has confirmed the existence of drug expenditure variability among comparable dermatology departments. Copyright © 2013 SEFH. Published by AULA MEDICA. All rights reserved.

  19. Analytic central path, sensitivity analysis and parametric linear programming

    NARCIS (Netherlands)

    A.G. Holder; J.F. Sturm; S. Zhang (Shuzhong)

    1998-01-01

    textabstractIn this paper we consider properties of the central path and the analytic center of the optimal face in the context of parametric linear programming. We first show that if the right-hand side vector of a standard linear program is perturbed, then the analytic center of the optimal face

  20. Convergence of Residential Gateway technology: analysis of evolutionary paths

    NARCIS (Netherlands)

    Hartog, den F.T.H.; Balm, M.; Jong, de C.M.; Kwaaitaal, J.J.B.

    2004-01-01

    A new OSI (Open Systems Interconnection)-based model is described that can be used for the classification of residential gateways (RG). It is applied to analyze current gateway solutions and to draw evolutionary paths for the mid-to-long term. It is concluded that set-top boxes and broadband modems

  1. Interactive analysis of geographically distributed population imaging data collections over light-path data networks

    Science.gov (United States)

    van Lew, Baldur; Botha, Charl P.; Milles, Julien R.; Vrooman, Henri A.; van de Giessen, Martijn; Lelieveldt, Boudewijn P. F.

    2015-03-01

    The cohort size required in epidemiological imaging genetics studies often mandates the pooling of data from multiple hospitals. Patient data, however, is subject to strict privacy protection regimes, and physical data storage may be legally restricted to a hospital network. To enable biomarker discovery, fast data access and interactive data exploration must be combined with high-performance computing resources, while respecting privacy regulations. We present a system using fast and inherently secure light-paths to access distributed data, thereby obviating the need for a central data repository. A secure private cloud computing framework facilitates interactive, computationally intensive exploration of this geographically distributed, privacy sensitive data. As a proof of concept, MRI brain imaging data hosted at two remote sites were processed in response to a user command at a third site. The system was able to automatically start virtual machines, run a selected processing pipeline and write results to a user accessible database, while keeping data locally stored in the hospitals. Individual tasks took approximately 50% longer compared to a locally hosted blade server but the cloud infrastructure reduced the total elapsed time by a factor of 40 using 70 virtual machines in the cloud. We demonstrated that the combination light-path and private cloud is a viable means of building an analysis infrastructure for secure data analysis. The system requires further work in the areas of error handling, load balancing and secure support of multiple users.

  2. Genetic variability, heritability, character association and path analysis in F/sub 1/ hybrids of tomato

    International Nuclear Information System (INIS)

    Saleem, M.Y.; Iqbal, Q.; Asghar, M.

    2013-01-01

    Twenty-five F/sub 1/ hybrids generated from 5*5 diallel crosses were evaluated to study the quantitative genetics of yield and some yield related traits during 2009-10. Worth of room was realized for improvement due to highly significant genetic variations among all traits studied. The highest estimates of genotypic and phenotypic coefficients of variability were recorded for number of fruits per plant while fruit width was the most heritable trait. Plant height, number of fruits per plant and fruit weight revealed significant positive genotypic and phenotypic association along with direct positive effect on fruit yield per plant. It is therefore, recommended that fruit weight, number of fruits per plant and plant height should be given due importance in selection of promising crosses to develop commercial hybrid variety in tomato. (author)

  3. Effective Analysis of C Programs by Rewriting Variability

    DEFF Research Database (Denmark)

    Iosif-Lazar, Alexandru Florin; Melo, Jean; Dimovski, Aleksandar

    2017-01-01

    and effective analysis and verification of real-world C program families. Importance. We report some interesting variability-related bugs that we discovered using various state-of-the-art single-program C verification tools, such as Frama-C, Clang, LLBMC.......Context. Variability-intensive programs (program families) appear in many application areas and for many reasons today. Different family members, called variants, are derived by switching statically configurable options (features) on and off, while reuse of the common code is maximized. Inquiry....... Verification of program families is challenging since the number of variants is exponential in the number of features. Existing single-program analysis and verification tools cannot be applied directly to program families, and designing and implementing the corresponding variability-aware versions is tedious...

  4. Computing paths and cycles in biological interaction graphs

    Directory of Open Access Journals (Sweden)

    von Kamp Axel

    2009-06-01

    Full Text Available Abstract Background Interaction graphs (signed directed graphs provide an important qualitative modeling approach for Systems Biology. They enable the analysis of causal relationships in cellular networks and can even be useful for predicting qualitative aspects of systems dynamics. Fundamental issues in the analysis of interaction graphs are the enumeration of paths and cycles (feedback loops and the calculation of shortest positive/negative paths. These computational problems have been discussed only to a minor extent in the context of Systems Biology and in particular the shortest signed paths problem requires algorithmic developments. Results We first review algorithms for the enumeration of paths and cycles and show that these algorithms are superior to a recently proposed enumeration approach based on elementary-modes computation. The main part of this work deals with the computation of shortest positive/negative paths, an NP-complete problem for which only very few algorithms are described in the literature. We propose extensions and several new algorithm variants for computing either exact results or approximations. Benchmarks with various concrete biological networks show that exact results can sometimes be obtained in networks with several hundred nodes. A class of even larger graphs can still be treated exactly by a new algorithm combining exhaustive and simple search strategies. For graphs, where the computation of exact solutions becomes time-consuming or infeasible, we devised an approximative algorithm with polynomial complexity. Strikingly, in realistic networks (where a comparison with exact results was possible this algorithm delivered results that are very close or equal to the exact values. This phenomenon can probably be attributed to the particular topology of cellular signaling and regulatory networks which contain a relatively low number of negative feedback loops. Conclusion The calculation of shortest positive

  5. Real analysis series, functions of several variables, and applications

    CERN Document Server

    Laczkovich, Miklós

    2017-01-01

    This book develops the theory of multivariable analysis, building on the single variable foundations established in the companion volume, Real Analysis: Foundations and Functions of One Variable. Together, these volumes form the first English edition of the popular Hungarian original, Valós Analízis I & II, based on courses taught by the authors at Eötvös Loránd University, Hungary, for more than 30 years. Numerous exercises are included throughout, offering ample opportunities to master topics by progressing from routine to difficult problems. Hints or solutions to many of the more challenging exercises make this book ideal for independent study, or further reading. Intended as a sequel to a course in single variable analysis, this book builds upon and expands these ideas into higher dimensions. The modular organization makes this text adaptable for either a semester or year-long introductory course. Topics include: differentiation and integration of functions of several variables; infinite numerica...

  6. Ted Irving and the Arc of APW Paths

    Science.gov (United States)

    Kent, D. V.

    2014-12-01

    Ted Irving's last two published papers neatly encapsulate his seminal contributions to the delineation of ever-important apparent polar wander (APW) paths. His final (210th) paper [Creer & Irving, 2012 Earth Sciences History] describes in detail how Ken Creer and he when still graduate students at Cambridge started to generate and assemble paleomagnetic data for the first APW path, for then only the UK; the paper was published 60 years ago and happened to be Ted's first [Creer, Irving & Runcorn, 1954 JGE]. Only 10 years later, there was already a lengthy reference list of paleomagnetic results available from most continents that had been compiled in pole lists he published in GJRAS from 1960 to 1965 and included in an appendix in his landmark book "Paleomagnetism" [Irving, 1964 Wiley] in support of wide ranging discussions of continental drift and related topics in chapters like 'Paleolatitudes and paleomeridians.' A subsequent innovation was calculating running means of poles indexed to a numerical geologic time scale [Irving, 1977 Nature], which with independent tectonic reconstructions as already for Gondwana allowed constructions of more detailed composite APW paths. His 1977 paper also coined Pangea B for an earlier albeit contentious configuration for the supercontinent that refuses to go away. Gliding over much work on APW tracks and hairpins in the Precambrian, we come to Ted's penultimate (209th) paper [Kent & Irving, 2010 JGR] in which individual poles from short-lived large igneous provinces were grouped and most sedimentary poles, many rather venerable, excluded as likely to be biased by variable degrees of inclination error. The leaner composite APW path helped to resurrect the Baja BC scenario of Cordilleran terrane motions virtually stopped in the 1980s by APW path techniques that relied on a few key but alas often badly skewed poles. The new composite APW path also revealed several major features, such as a huge polar shift of 30° in 15 Myr in the

  7. Identifying associated factors with social capital using path analysis: A population-based survey in Tehran, Iran (Urban HEART-2).

    Science.gov (United States)

    Asadi-Lari, Mohsen; Hassanzadeh, Jafar; Torabinia, Mansour; Vaez-Mahdavi, Mohammad Reza; Montazeri, Ali; Ghaem, Haleh; Menati, Rostam; Niazi, Mohsen; Kassani, Aziz

    2016-01-01

    Background: Social capital has been defined as norms, networks, and social links that facilitate collective actions. Social capital is related to a number of main social and public health variables. Therefore, the present study aimed to determine the factors associated with social capital among the residents of Tehran, Iran. Methods: In this large cross-sectional population-based study, 31531 residents aged 20 years and above were selected through multi-stage sampling method from 22 districts of Tehran in 2011. The social capital questionnaire, 28-item General Health Questionnaire (GHQ-28), and Short-Form Health Survey (SF-12) were used. Hypothetical causal models were designed to identify the pathways through which different variables influenced the components of social capital. Then, path analysis was conducted for identifying the determinants of social capital. Results: The most influential variables in 'individual trust' were job status (β=0.37, p=0.02), marital status (β=0.32, p=0.01), Physical Component Summary (PCS) (β=0.37, p=0.02), and age (β=0.34, p=0.03). On the other hand, education level (β=0.34, p=0.01), age (β=0.33, p=0.02), marital status (β=0.33, p=0.01), and job status (β=0.32, p=0.01) were effective in 'cohesion and social support'. Additionally, age (β=0.18, p=0.02), PCS (β=0.36, p=0.01), house ownership (β=0.23, p=0.03), and mental health (β=0.26, p=0.01) were influential in 'social trust/collective relations'. Conclusion: Social capital can be improved in communities by planning to improve education and occupation status, paying more attention to strengthening family bonds, and provision of local facilities and neighborhood bonds to reduce migration within the city.

  8. A meta analysis of the variability in firm performance attributable to human resource variables

    Directory of Open Access Journals (Sweden)

    Lloyd Kapondoro

    2015-01-01

    Full Text Available The contribution of Human Resource Management (HRM practices to organisation-wide performance is a critical aspect of the Human Resource (HR value proposition. The purpose of the study was to describe the strength of HRM practices and systems in influencing overall organisational performance. While research has concluded that there is a significant positive relationship between HRM practices or systems and an organisation’s market performance, the strength of this relationship has relatively not received much analysis in order to explain the degree to which HRM practices explain variance in firm performance. The study undertook a meta-analysis of published researches in international journals. The study established that HRM variables accounted for an average of 31% of the variability in firm performance. Cohen’s f2 calculated for this study as a meta effect size calculation yielded an average of 0.681, implying that HRM variables account for 68% of variability in firm performance. A one sample Kolmogorov-Smirnov test showed that the distribution of R2 is not normal. A major managerial implication of this study is that effective HRM practices have a significant business case. The study provides, quantitatively, the average variability in firm success that HRM accounts for.

  9. Path integral measure and the fermion-boson equivalence in the Schwinger model

    International Nuclear Information System (INIS)

    Maiella, G.

    1980-02-01

    I perform a change of field variables in the Schwinger model using the non-invariance of path integral measure under γ 5 transformations. The known equivalence of the model with a bosonic field theory and the Kogut-Susskind dipole mechanism is then derived. (author)

  10. Vapor nucleation paths in lyophobic nanopores.

    Science.gov (United States)

    Tinti, Antonio; Giacomello, Alberto; Casciola, Carlo Massimo

    2018-04-19

    In recent years, technologies revolving around the use of lyophobic nanopores gained considerable attention in both fundamental and applied research. Owing to the enormous internal surface area, heterogeneous lyophobic systems (HLS), constituted by a nanoporous lyophobic material and a non-wetting liquid, are promising candidates for the efficient storage or dissipation of mechanical energy. These diverse applications both rely on the forced intrusion and extrusion of the non-wetting liquid inside the pores; the behavior of HLS for storage or dissipation depends on the hysteresis between these two processes, which, in turn, are determined by the microscopic details of the system. It is easy to understand that molecular simulations provide an unmatched tool for understanding phenomena at these scales. In this contribution we use advanced atomistic simulation techniques in order to study the nucleation of vapor bubbles inside lyophobic mesopores. The use of the string method in collective variables allows us to overcome the computational challenges associated with the activated nature of the phenomenon, rendering a detailed picture of nucleation in confinement. In particular, this rare event method efficiently searches for the most probable nucleation path(s) in otherwise intractable, high-dimensional free-energy landscapes. Results reveal the existence of several independent nucleation paths associated with different free-energy barriers. In particular, there is a family of asymmetric transition paths, in which a bubble forms at one of the walls; the other family involves the formation of axisymmetric bubbles with an annulus shape. The computed free-energy profiles reveal that the asymmetric path is significantly more probable than the symmetric one, while the exact position where the asymmetric bubble forms is less relevant for the free energetics of the process. A comparison of the atomistic results with continuum models is also presented, showing how, for simple

  11. Stage-by-Stage and Parallel Flow Path Compressor Modeling for a Variable Cycle Engine, NASA Advanced Air Vehicles Program - Commercial Supersonic Technology Project - AeroServoElasticity

    Science.gov (United States)

    Kopasakis, George; Connolly, Joseph W.; Cheng, Larry

    2015-01-01

    This paper covers the development of stage-by-stage and parallel flow path compressor modeling approaches for a Variable Cycle Engine. The stage-by-stage compressor modeling approach is an extension of a technique for lumped volume dynamics and performance characteristic modeling. It was developed to improve the accuracy of axial compressor dynamics over lumped volume dynamics modeling. The stage-by-stage compressor model presented here is formulated into a parallel flow path model that includes both axial and rotational dynamics. This is done to enable the study of compressor and propulsion system dynamic performance under flow distortion conditions. The approaches utilized here are generic and should be applicable for the modeling of any axial flow compressor design accurate time domain simulations. The objective of this work is as follows. Given the parameters describing the conditions of atmospheric disturbances, and utilizing the derived formulations, directly compute the transfer function poles and zeros describing these disturbances for acoustic velocity, temperature, pressure, and density. Time domain simulations of representative atmospheric turbulence can then be developed by utilizing these computed transfer functions together with the disturbance frequencies of interest.

  12. Hierarchy of Dysfunction Related to Dressing Performance in Stroke Patients: A Path Analysis Study.

    Science.gov (United States)

    Fujita, Takaaki; Nagayama, Hirofumi; Sato, Atsushi; Yamamoto, Yuichi; Yamane, Kazuhiro; Otsuki, Koji; Tsuchiya, Kenji; Tozato, Fusae

    2016-01-01

    Previous reports indicated that various dysfunctions caused by stroke affect the level of independence in dressing. These dysfunctions can be hierarchical, and these effects on dressing performance can be complicated in stroke patients. However, there are no published reports focusing on the hierarchical structure of the relationships between the activities of daily living and balance function, motor and sensory functions of the affected lower limb, strength of the abdominal muscles and knee extension on the unaffected side, and visuospatial deficits. The purpose of this study was to elucidate the hierarchical and causal relationships between dressing performance and these dysfunctions in stroke patients. This retrospective study included 104 first-time stroke patients. The causal relationship between the dressing performance and age, time post stroke, balance function, motor and sensory functions of the affected lower limb, strength of the abdominal muscles and knee extension on the unaffected side, and visuospatial deficits were examined using path analysis. A hypothetical path model was created based on previous studies, and the goodness of fit between the data and model were verified. A modified path model was created that achieved an almost perfect fit to the data. Balance function and abdominal muscle strength have direct effects on dressing performance, with standardized direct effect estimates of 0.78 and 0.15, respectively. Age, motor and sensory functions of the affected lower limb, and strength of abdominal muscle and knee extension on the unaffected side have indirect effects on dressing by influencing balance function. Our results suggest that dressing performance depends strongly on balance function, and it is mainly influenced by the motor function of the affected lower limb.

  13. Hierarchy of Dysfunction Related to Dressing Performance in Stroke Patients: A Path Analysis Study.

    Directory of Open Access Journals (Sweden)

    Takaaki Fujita

    Full Text Available Previous reports indicated that various dysfunctions caused by stroke affect the level of independence in dressing. These dysfunctions can be hierarchical, and these effects on dressing performance can be complicated in stroke patients. However, there are no published reports focusing on the hierarchical structure of the relationships between the activities of daily living and balance function, motor and sensory functions of the affected lower limb, strength of the abdominal muscles and knee extension on the unaffected side, and visuospatial deficits. The purpose of this study was to elucidate the hierarchical and causal relationships between dressing performance and these dysfunctions in stroke patients. This retrospective study included 104 first-time stroke patients. The causal relationship between the dressing performance and age, time post stroke, balance function, motor and sensory functions of the affected lower limb, strength of the abdominal muscles and knee extension on the unaffected side, and visuospatial deficits were examined using path analysis. A hypothetical path model was created based on previous studies, and the goodness of fit between the data and model were verified. A modified path model was created that achieved an almost perfect fit to the data. Balance function and abdominal muscle strength have direct effects on dressing performance, with standardized direct effect estimates of 0.78 and 0.15, respectively. Age, motor and sensory functions of the affected lower limb, and strength of abdominal muscle and knee extension on the unaffected side have indirect effects on dressing by influencing balance function. Our results suggest that dressing performance depends strongly on balance function, and it is mainly influenced by the motor function of the affected lower limb.

  14. The relation between operator and path integral covariant quantizations of the Green-Schwarz superstring

    International Nuclear Information System (INIS)

    Nissimov, E.; Pacheva, S.; Solomon, S.

    1989-02-01

    By further study of the geometry of the harmonic superspace constraints, we make explicit the relation between the operator and path integral approaches to the manifestly covariant harmonic superstring. In particular we find the correct complete set of functionally independent gauge symmetries for the auxiliary variables and identify the ones corresponding to the harmonic superfield postulate in the operator formalism. Then, we deduce in a systematic way the lagrangian path integral from the well defined covariant hamiltonian formulation of the GS superstring. (authors)

  15. Efficient Unbiased Rendering using Enlightened Local Path Sampling

    DEFF Research Database (Denmark)

    Kristensen, Anders Wang

    measurements, which are the solution to the adjoint light transport problem. The second is a representation of the distribution of radiance and importance in the scene. We also derive a new method of particle sampling, which is advantageous compared to existing methods. Together we call the resulting algorithm....... The downside to using these algorithms is that they can be slow to converge. Due to the nature of Monte Carlo methods, the results are random variables subject to variance. This manifests itself as noise in the images, which can only be reduced by generating more samples. The reason these methods are slow...... is because of a lack of eeffective methods of importance sampling. Most global illumination algorithms are based on local path sampling, which is essentially a recipe for constructing random walks. Using this procedure paths are built based on information given explicitly as part of scene description...

  16. A new path-integral representation of the T-matrix in potential scattering

    International Nuclear Information System (INIS)

    Carron, J.; Rosenfelder, R.

    2011-01-01

    We employ the method used by Barbashov and collaborators in Quantum Field Theory to derive a path-integral representation of the T-matrix in nonrelativistic potential scattering which is free of functional integration over fictitious variables as was necessary before. The resulting expression serves as a starting point for a variational approximation applied to high-energy scattering from a Gaussian potential. Good agreement with exact partial-wave calculations is found even at large scattering angles. A novel path-integral representation of the scattering length is obtained in the low-energy limit. -- Highlights: → We derive a new path-integral representation for the T-matrix in quantum scattering from a potential. → The method is based on a technique used by Barbashov and collaborators in Quantum Field Theory. → Unlike previous approaches no unphysical degrees of freedom in the path integral are needed. → The new representation is used for a variational approximation of the T-matrix at high energies. → A new expression for the scattering length at low energy is derived.

  17. NASA Systems Engineering Research Consortium: Defining the Path to Elegance in Systems

    Science.gov (United States)

    Watson, Michael D.; Farrington, Phillip A.

    2016-01-01

    The NASA Systems Engineering Research Consortium was formed at the end of 2010 to study the approaches to producing elegant systems on a consistent basis. This has been a transformative study looking at the engineering and organizational basis of systems engineering. The consortium has engaged in a variety of research topics to determine the path to elegant systems. In the second year of the consortium, a systems engineering framework emerged which structured the approach to systems engineering and guided our research. This led in the third year to set of systems engineering postulates that the consortium is continuing to refine. The consortium has conducted several research projects that have contributed significantly to the understanding of systems engineering. The consortium has surveyed the application of the NASA 17 systems engineering processes, explored the physics and statistics of systems integration, and considered organizational aspects of systems engineering discipline integration. The systems integration methods have included system exergy analysis, Akaike Information Criteria (AIC), State Variable Analysis, Multidisciplinary Coupling Analysis (MCA), Multidisciplinary Design Optimization (MDO), System Cost Modelling, System Robustness, and Value Modelling. Organizational studies have included the variability of processes in change evaluations, margin management within the organization, information theory of board structures, social categorization of unintended consequences, and initial looks at applying cognitive science to systems engineering. Consortium members have also studied the bidirectional influence of policy and law with systems engineering.

  18. Scalable conditional induction variables (CIV) analysis

    DEFF Research Database (Denmark)

    Oancea, Cosmin Eugen; Rauchwerger, Lawrence

    2015-01-01

    parallelizing compiler and evaluated its impact on five Fortran benchmarks. We have found that that there are many important loops using CIV subscripts and that our analysis can lead to their scalable parallelization. This in turn has led to the parallelization of the benchmark programs they appear in.......Subscripts using induction variables that cannot be expressed as a formula in terms of the enclosing-loop indices appear in the low-level implementation of common programming abstractions such as filter, or stack operations and pose significant challenges to automatic parallelization. Because...... the complexity of such induction variables is often due to their conditional evaluation across the iteration space of loops we name them Conditional Induction Variables (CIV). This paper presents a flow-sensitive technique that summarizes both such CIV-based and affine subscripts to program level, using the same...

  19. The influence of parenting style on academic achievement and career path.

    Science.gov (United States)

    Zahed Zahedani, Zahra; Rezaee, Rita; Yazdani, Zahra; Bagheri, Sina; Nabeiei, Parisa

    2016-07-01

    Several factors affect the academic performance of college students and parenting style is one significant factor. The current study has been done with the purpose of investigating the relationship between parenting styles, academic achievement and career path of students at Shiraz University of Medical Sciences. This is a correlation study carried out at Shiraz University of Medical Sciences. Among 1600 students, 310 students were selected randomly as the sample. Baumrind's Parenting Style and Moqimi's Career Path questionnaires were used and the obtained scores were correlated with the students' transcripts. To study the relation between variables Pearson correlation coefficient was used. There was a significant relationship between authoritarian parenting style and educational success (p=0.03). Also findings showed a significant relationship between firm parenting style and Career Path of the students, authoritarian parenting style and Career Path of the students, educational success and Career Path of the students (p=0.001). Parents have an important role in identifying children's talent and guiding them. Mutual understanding and close relationship between parents and children are recommended. Therefore, it is recommended that the methods of correct interaction of parents and children be more valued and parents familiarize their children with roles of businesses in society and the need for employment in legitimate businesses and this important affair should be more emphasized through mass media and family training classes.

  20. Social Cognitive Constructs Did Not Mediate the BEAT Cancer Intervention Effects on Objective Physical Activity Behavior Based on Multivariable Path Analysis.

    Science.gov (United States)

    Rogers, Laura Q; Courneya, Kerry S; Anton, Phillip M; Hopkins-Price, Patricia; Verhulst, Steven; Robbs, Randall S; Vicari, Sandra K; McAuley, Edward

    2017-04-01

    Most breast cancer survivors do not meet physical activity recommendations. Understanding mediators of physical activity behavior change can improve interventions designed to increase physical activity in this at-risk population. Study aims were to determine the 3-month Better Exercise Adherence after Treatment for Cancer (BEAT Cancer) behavior change intervention effects on social cognitive theory constructs and the mediating role of any changes on the increase in accelerometer-measured physical activity previously reported. Post-treatment breast cancer survivors (N = 222) were randomized to BEAT Cancer or usual care. Assessments occurred at baseline, 3 months (M3), and 6 months (M6). Adjusted linear mixed model analysis of variance determined intervention effects on walking self-efficacy, outcome expectations, goal setting, and perceived barrier interference at M3. Path analysis determined mediation of intervention effects on physical activity at M6 by changes in social cognitive constructs during the intervention (i.e., baseline to M3). BEAT Cancer significantly improved self-efficacy, goals, negative outcome expectations, and barriers. Total path analysis model explained 24 % of the variance in M6 physical activity. There were significant paths from randomized intervention group to self-efficacy (β = 0.15, p social cognitive constructs, no significant indirect effects on physical activity improvements 3 months post-intervention were observed (NCT00929617).

  1. Association Between Short-Term Systolic Blood Pressure Variability and Carotid Intima-Media Thickness in ELSA-Brasil Baseline.

    Science.gov (United States)

    Ribeiro, Adèle H; Lotufo, Paulo A; Fujita, André; Goulart, Alessandra C; Chor, Dora; Mill, José G; Bensenor, Isabela M; Santos, Itamar S

    2017-10-01

    Blood pressure (BP) is associated with carotid intima-media thickness (CIMT), but few studies have explored the association between BP variability and CIMT. We aimed to investigate this association in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) baseline. We analyzed data from 7,215 participants (56.0% women) without overt cardiovascular disease (CVD) or antihypertensive use. We included 10 BP readings in varying positions during a 6-hour visit. We defined BP variability as the SD of these readings. We performed a 2-step analysis. We first linearly regressed the CIMT values on main and all-order interaction effects of the variables age, sex, body mass index, race, diabetes diagnosis, dyslipidemia diagnosis, family history of premature CVD, smoking status, and ELSA-Brasil site, and calculated the residuals (residual CIMT). We used partial least square path analysis to investigate whether residual CIMT was associated with BP central tendency and BP variability. Systolic BP (SBP) variability was significantly associated with residual CIMT in models including the entire sample (path coefficient [PC]: 0.046; P < 0.001), and in women (PC: 0.046; P = 0.007) but not in men (PC: 0.037; P = 0.09). This loss of significance was probably due to the smaller subsample size, as PCs were not significantly different according to sex. We found a small but significant association between SBP variability and CIMT values. This was additive to the association between SBP central tendency and CIMT values, supporting a role for high short-term SBP variability in atherosclerosis. © American Journal of Hypertension, Ltd 2017. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  2. PTRACK: A particle tracking program for evaluation travel path/travel time uncertainties

    International Nuclear Information System (INIS)

    Thompson, B.M.; Campbell, J.E.; Longsine, D.E.

    1987-12-01

    PTRACK is a model which tracks the path of a radionuclide particle released from a nuclear waste repository into a ground-water flow system in a two-dimensional representation of stratified geologic medium. The code calculates the time required for the particle to travel from the release point (the edge of the disturbed zone) to the specified horizontal or vertical boundary (the accessible environment). The physical properties of the geologic setting and the ground-water flow system can be treated as fixed values or as random variables sampled from their respective probability distributions. In the latter case, PTRACK assigns a sampled value for each parameter and tracks a particle for this trial (realization) of the system. Repeated realizations allow the effects of parameter uncertainty on travel paths/travel times to be quantified. The code can also calculate partial correlation coefficients between dependent variables and independent variables, which are useful in identifying important independent variables. This documentation describes the mathematical basis for the model, the algorithms and solution techniques used, and the computer code design. It also contains a detailed user's manual. The implementation of PTRACK is verified with several systems for which solutions have been calculated by hand. The integration of PTRACK with a Latin hypercube sampling (LHS) code is also discussed, although other sampling methods can be employed in place of LHS. 11 refs., 14 figs., 22 tabs

  3. Learning to improve path planning performance

    International Nuclear Information System (INIS)

    Chen, Pang C.

    1995-04-01

    In robotics, path planning refers to finding a short. collision-free path from an initial robot configuration to a desired configuratioin. It has to be fast to support real-time task-level robot programming. Unfortunately, current planning techniques are still too slow to be effective, as they often require several minutes, if not hours of computation. To remedy this situation, we present and analyze a learning algorithm that uses past experience to increase future performance. The algorithm relies on an existing path planner to provide solutions to difficult tasks. From these solutions, an evolving sparse network of useful robot configurations is learned to support faster planning. More generally, the algorithm provides a speedup-learning framework in which a slow but capable planner may be improved both cost-wise and capability-wise by a faster but less capable planner coupled with experience. The basic algorithm is suitable for stationary environments, and can be extended to accommodate changing environments with on-demand experience repair and object-attached experience abstraction. To analyze the algorithm, we characterize the situations in which the adaptive planner is useful, provide quantitative bounds to predict its behavior, and confirm our theoretical results with experiments in path planning of manipulators. Our algorithm and analysis are sufficiently, general that they may also be applied to other planning domains in which experience is useful

  4. Path integration quantization

    International Nuclear Information System (INIS)

    DeWitt-Morette, C.

    1983-01-01

    Much is expected of path integration as a quantization procedure. Much more is possible if one recognizes that path integration is at the crossroad of stochastic and differential calculus and uses the full power of both stochastic and differential calculus in setting up and computing path integrals. In contrast to differential calculus, stochastic calculus has only comparatively recently become an instrument of thought. It has nevertheless already been used in a variety of challenging problems, for instance in the quantization problem. The author presents some applications of the stochastic scheme. (Auth.)

  5. Analysis on influence factors of China's CO2 emissions based on Path-STIRPAT model

    International Nuclear Information System (INIS)

    Li Huanan; Mu Hailin; Zhang Ming; Li Nan

    2011-01-01

    With the intensification of global warming and continued growth in energy consumption, China is facing increasing pressure to cut its CO 2 (carbon dioxide) emissions down. This paper discusses the driving forces influencing China's CO 2 emissions based on Path-STIRPAT model-a method combining Path analysis with STIRPAT (stochastic impacts by regression on population, affluence and technology) model. The analysis shows that GDP per capita (A), industrial structure (IS), population (P), urbanization level (R) and technology level (T) are the main factors influencing China's CO 2 emissions, which exert an influence interactively and collaboratively. The sequence of the size of factors' direct influence on China's CO 2 emission is A>T>P>R>IS, while that of factors' total influence is A>R>P>T>IS. One percent increase in A, IS, P, R and T leads to 0.44, 1.58, 1.31, 1.12 and -1.09 percentage change in CO 2 emission totally, where their direct contribution is 0.45, 0.07, 0.63, 0.08, 0.92, respectively. Improving T is the most important way for CO 2 reduction in China. - Highlights: → We analyze the driving forces influencing China's CO 2 emissions. → Five macro factors like per capita GDP are the main influencing factors. → These factors exert an influence interactively and collaboratively. → Different factors' direct and total influence on China's CO 2 emission is different. → Improving technology level is the most important way for CO 2 reduction in China.

  6. Analysis of rain fade duration models for Earth-to-satellite path based on data measured in Malaysia

    International Nuclear Information System (INIS)

    Dao, Hassan; Rafiqul, Islam Md; Al-Khateeb, Khalid A S

    2013-01-01

    Statistical analysis of rain fade duration is crucial information for system engineer to design and plan a fade mitigation technique (FMT) for the satellite communication system. An investigation is carried out based on data measured of one year period in Kuala Lumpur, Malaysia from satellite path of MEASAT3. This paper presents statistical analysis of measured fade duration on high elevation angle (77.4°) in Ku-band compared to three prediction models of fade duration. It is found that none of the models could predict measured fade duration distribution accurately

  7. Some Cognitive Variables in Meaningful Learning of the Physics Concepts of Work and Energy: A Study of Ausubelian Learning Model.

    Science.gov (United States)

    Talisayon, Vivien Millan

    This study is an empirical investigation of Ausubel's paradigm of meaningful learning, applied specifically to the learning of high school physics students. In the first phase of the study path analysis and multiple regression techniques were used to describe the Ausubelian learning variables: available relevant ideas in learner's cognitive…

  8. Utilization of Multimedia Laboratory: An Acceptance Analysis using TAM

    Science.gov (United States)

    Modeong, M.; Palilingan, V. R.

    2018-02-01

    Multimedia is often utilized by teachers to present a learning materials. Learning that delivered by multimedia enables people to understand the information of up to 60% of the learning in general. To applying the creative learning to the classroom, multimedia presentation needs a laboratory as a space that provides multimedia needs. This study aims to reveal the level of student acceptance on the multimedia laboratories, by explaining the direct and indirect effect of internal support and technology infrastructure. Technology Acceptance Model (TAM) is used as the basis of measurement on this research, through the perception of usefulness, ease of use, and the intention, it’s recognized capable of predicting user acceptance about technology. This study used the quantitative method. The data analysis using path analysis that focuses on trimming models, it’s performed to improve the model of path analysis structure by removing exogenous variables that have insignificant path coefficients. The result stated that Internal Support and Technology Infrastructure are well mediated by TAM variables to measure the level of technology acceptance. The implications suggest that TAM can measure the success of multimedia laboratory utilization in Faculty of Engineering UNIMA.

  9. Analysis of factors controlling soil phosphorus loss with surface runoff in Huihe National Nature Reserve by principal component and path analysis methods.

    Science.gov (United States)

    He, Jing; Su, Derong; Lv, Shihai; Diao, Zhaoyan; Bu, He; Wo, Qiang

    2018-01-01

    Phosphorus (P) loss with surface runoff accounts for the P input to and acceleration of eutrophication of the freshwater. Many studies have focused on factors affecting P loss with surface runoff from soils, but rarely on the relationship among these factors. In the present study, rainfall simulation on P loss with surface runoff was conducted in Huihe National Nature Reserve, in Hulunbeier grassland, China, and the relationships between P loss with surface runoff, soil properties, and rainfall conditions were examined. Principal component analysis and path analysis were used to analyze the direct and indirect effects on P loss with surface runoff. The results showed that P loss with surface runoff was closely correlated with soil electrical conductivity, soil pH, soil Olsen P, soil total nitrogen (TN), soil total phosphorus (TP), and soil organic carbon (SOC). The main driving factors which influenced P loss with surface runoff were soil TN, soil pH, soil Olsen P, and soil water content. Path analysis and determination coefficient analysis indicated that the standard multiple regression equation for P loss with surface runoff and each main factor was Y = 7.429 - 0.439 soil TN - 6.834 soil pH + 1.721 soil Olsen-P + 0.183 soil water content (r = 0.487, p runoff. The effect of physical and chemical properties of undisturbed soils on P loss with surface runoff was discussed, and the soil water content and soil Olsen P were strongly positive influences on the P loss with surface runoff.

  10. Spin-path entanglement in single-neutron interferometer experiments

    International Nuclear Information System (INIS)

    Hasegawa, Yuji; Erdoesi, Daniel

    2011-01-01

    There are two powerful arguments against the possibility of extending quantum mechanics (QM) into a more fundamental theory yielding a deterministic description of nature. One is the experimental violation of Bell inequalities, which discards local hidden-variable theories as a possible extension to QM. The other is the Kochen-Specker (KS) theorem, which stresses the incompatibility of QM with a larger class of hidden-variable theories, known as noncontextual hidden-variable theories. We performed experiments with neutron interferometer, which exploits spin-path entanglements in single neutrons. A Bell-like state is generated to demonstrate a violation of the Bell-like inequality and phenomena in accordance with KS theorem: both experiments study quantum contextuality and show clear evidence of the incompatibility of noncontextual hidden variable theories with QM. The value S = 2.202±0.007≰2 is obtained in the new measurement of the Bell-like inequality, which shows a larger violation than the previous measurement. For the study of KS theorem, the obtained violation 2.291±0.008≰1 clearly shows that quantum mechanical predictions cannot be reproduced by noncontextual hidden variable theories.

  11. Reparametrization in the path integral

    International Nuclear Information System (INIS)

    Storchak, S.N.

    1983-01-01

    The question of the invariance of a measure in the n-dimensional path integral under the path reparametrization is considered. The non-invariance of the measure through the jacobian is suggeste. After the path integral reparametrization the representatioq for the Green's function of the Hamilton operator in terms of the path integral with the classical Hamiltonian has been obtained

  12. Unique Path Partitions

    DEFF Research Database (Denmark)

    Bessenrodt, Christine; Olsson, Jørn Børling; Sellers, James A.

    2013-01-01

    We give a complete classification of the unique path partitions and study congruence properties of the function which enumerates such partitions.......We give a complete classification of the unique path partitions and study congruence properties of the function which enumerates such partitions....

  13. The effects of shear and normal stress paths on rock friction

    International Nuclear Information System (INIS)

    Olsson, W.A.

    1990-01-01

    The effect of variable normal stress on the coefficient of friction of smooth artificial surfaces in welded tuff was studied. The shear stress response to changes in normal stress during constant-velocity sliding suggests that friction depends on the history of the normal stress; or, more generally, the path in shear/normal stress space. 6 refs., 5 figs

  14. Extended shortest path selection for package routing of complex networks

    Science.gov (United States)

    Ye, Fan; Zhang, Lei; Wang, Bing-Hong; Liu, Lu; Zhang, Xing-Yi

    The routing strategy plays a very important role in complex networks such as Internet system and Peer-to-Peer networks. However, most of the previous work concentrates only on the path selection, e.g. Flooding and Random Walk, or finding the shortest path (SP) and rarely considering the local load information such as SP and Distance Vector Routing. Flow-based Routing mainly considers load balance and still cannot achieve best optimization. Thus, in this paper, we propose a novel dynamic routing strategy on complex network by incorporating the local load information into SP algorithm to enhance the traffic flow routing optimization. It was found that the flow in a network is greatly affected by the waiting time of the network, so we should not consider only choosing optimized path for package transformation but also consider node congestion. As a result, the packages should be transmitted with a global optimized path with smaller congestion and relatively short distance. Analysis work and simulation experiments show that the proposed algorithm can largely enhance the network flow with the maximum throughput within an acceptable calculating time. The detailed analysis of the algorithm will also be provided for explaining the efficiency.

  15. Using meta-analytic path analysis to test theoretical predictions in health behavior: An illustration based on meta-analyses of the theory of planned behavior

    OpenAIRE

    Hagger, Martin; Chan, Dervin K. C.; Protogerou, Cleo; Chatzisarantis, Nikos L. D.

    2016-01-01

    Objective Synthesizing research on social cognitive theories applied to health behavior is an important step in the development of an evidence base of psychological factors as targets for effective behavioral interventions. However, few meta-analyses of research on social cognitive theories in health contexts have conducted simultaneous tests of theoretically-stipulated pattern effects using path analysis. We argue that conducting path analyses of meta-analytic effects among constructs fr...

  16. A semi-empirical analysis of strong-motion peaks in terms of seismic source, propagation path, and local site conditions

    Science.gov (United States)

    Kamiyama, M.; Orourke, M. J.; Flores-Berrones, R.

    1992-09-01

    A new type of semi-empirical expression for scaling strong-motion peaks in terms of seismic source, propagation path, and local site conditions is derived. Peak acceleration, peak velocity, and peak displacement are analyzed in a similar fashion because they are interrelated. However, emphasis is placed on the peak velocity which is a key ground motion parameter for lifeline earthquake engineering studies. With the help of seismic source theories, the semi-empirical model is derived using strong motions obtained in Japan. In the derivation, statistical considerations are used in the selection of the model itself and the model parameters. Earthquake magnitude M and hypocentral distance r are selected as independent variables and the dummy variables are introduced to identify the amplification factor due to individual local site conditions. The resulting semi-empirical expressions for the peak acceleration, velocity, and displacement are then compared with strong-motion data observed during three earthquakes in the U.S. and Mexico.

  17. Shortest multiple disconnected path for the analysis of entanglements in two- and three-dimensional polymeric systems

    Science.gov (United States)

    Kröger, Martin

    2005-06-01

    We present an algorithm which returns a shortest path and related number of entanglements for a given configuration of a polymeric system in 2 or 3 dimensions. Rubinstein and Helfand, and later Everaers et al. introduced a concept to extract primitive paths for dense polymeric melts made of linear chains (a multiple disconnected multibead 'path'), where each primitive path is defined as a path connecting the (space-fixed) ends of a polymer under the constraint of non-interpenetration (excluded volume) between primitive paths of different chains, such that the multiple disconnected path fulfills a minimization criterion. The present algorithm uses geometrical operations and provides a—model independent—efficient approximate solution to this challenging problem. Primitive paths are treated as 'infinitely' thin (we further allow for finite thickness to model excluded volume), and tensionless lines rather than multibead chains, excluded volume is taken into account without a force law. The present implementation allows to construct a shortest multiple disconnected path (SP) for 2D systems (polymeric chain within spherical obstacles) and an optimal SP for 3D systems (collection of polymeric chains). The number of entanglements is then simply obtained from the SP as either the number of interior kinks, or from the average length of a line segment. Further, information about structure and potentially also the dynamics of entanglements is immediately available from the SP. We apply the method to study the 'concentration' dependence of the degree of entanglement in phantom chain systems. Program summaryTitle of program:Z Catalogue number:ADVG Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADVG Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Computer for which the program is designed and others on which it has been tested: Silicon Graphics (Irix), Sun (Solaris), PC (Linux) Operating systems or monitors under which the

  18. Iterated Leavitt Path Algebras

    International Nuclear Information System (INIS)

    Hazrat, R.

    2009-11-01

    Leavitt path algebras associate to directed graphs a Z-graded algebra and in their simplest form recover the Leavitt algebras L(1,k). In this note, we introduce iterated Leavitt path algebras associated to directed weighted graphs which have natural ± Z grading and in their simplest form recover the Leavitt algebras L(n,k). We also characterize Leavitt path algebras which are strongly graded. (author)

  19. Path Dependence

    DEFF Research Database (Denmark)

    Madsen, Mogens Ove

    Begrebet Path Dependence blev oprindelig udviklet inden for New Institutionel Economics af bl.a. David, Arthur og North. Begrebet har spredt sig vidt i samfundsvidenskaberne og undergået en udvikling. Dette paper propagerer for at der er sket så en så omfattende udvikling af begrebet, at man nu kan...... tale om 1. og 2. generation af Path Dependence begrebet. Den nyeste udvikling af begrebet har relevans for metodologi-diskusionerne i relation til Keynes...

  20. The influence of parenting style on academic achievement and career path

    Directory of Open Access Journals (Sweden)

    ZAHRA ZAHED ZAHEDANI

    2016-07-01

    Full Text Available Introduction: Several factors affect the academic performance of college students and parenting style is one significant factor. The current study has been done with the purpose of investigating the relationship between parenting styles, academic achievement and career path of students at Shiraz University of Medical Sciences. Methods: This is a correlation study carried out at Shiraz University of Medical Sciences. Among 1600 students, 310 students were selected randomly as the sample. Baumrind’s Parenting Style and Moqimi’s Career Path questionnaires were used and the obtained scores were correlated with the students’ transcripts. To study the relation between variables Pearson correlation coefficient was used. Results: There was a significant relationship between authoritarian parenting style and educational success (p=0.03. Also findings showed a significant relationship between firm parenting style and Career Path of the students, authoritarian parenting style and Career Path of the students, educational success and Career Path of the students (p=0.001. Conclusion: Parents have an important role in identifying children’s talent and guiding them. Mutual understanding and close relationship between parents and children are recommended. Therefore, it is recommended that the methods of correct interaction of parents and children be more valued and parents familiarize their children with roles of businesses in society and the need for employment in legitimate businesses and this important affair should be more emphasized through mass media and family training classes.

  1. The influence of parenting style on academic achievement and career path

    Science.gov (United States)

    ZAHED ZAHEDANI, ZAHRA; REZAEE, RITA; YAZDANI, ZAHRA; BAGHERI, SINA; NABEIEI, PARISA

    2016-01-01

    Introduction Several factors affect the academic performance of college students and parenting style is one significant factor. The current study has been done with the purpose of investigating the relationship between parenting styles, academic achievement and career path of students at Shiraz University of Medical Sciences.     Methods This is a correlation study carried out at Shiraz University of Medical Sciences. Among 1600 students, 310 students were selected randomly as the sample. Baumrind’s Parenting Style and Moqimi’s Career Path questionnaires were used and the obtained scores were correlated with the students' transcripts. To study the relation between variables Pearson correlation coefficient was used. Results There was a significant relationship between authoritarian parenting style and educational success (p=0.03). Also findings showed a significant relationship between firm parenting style and Career Path of the students, authoritarian parenting style and Career Path of the students, educational success and Career Path of the students (p=0.001). Conclusion Parents have an important role in identifying children’s talent and guiding them. Mutual understanding and close relationship between parents and children are recommended. Therefore, it is recommended that the methods of correct interaction of parents and children be more valued and parents familiarize their children with roles of businesses in society and the need for employment in legitimate businesses and this important affair should be more emphasized through mass media and family training classes. PMID:27382580

  2. Continuously variable focal length lens

    Science.gov (United States)

    Adams, Bernhard W; Chollet, Matthieu C

    2013-12-17

    A material preferably in crystal form having a low atomic number such as beryllium (Z=4) provides for the focusing of x-rays in a continuously variable manner. The material is provided with plural spaced curvilinear, optically matched slots and/or recesses through which an x-ray beam is directed. The focal length of the material may be decreased or increased by increasing or decreasing, respectively, the number of slots (or recesses) through which the x-ray beam is directed, while fine tuning of the focal length is accomplished by rotation of the material so as to change the path length of the x-ray beam through the aligned cylindrical slows. X-ray analysis of a fixed point in a solid material may be performed by scanning the energy of the x-ray beam while rotating the material to maintain the beam's focal point at a fixed point in the specimen undergoing analysis.

  3. Genotypic character relationship and phenotypic path coefficient analysis in chili pepper genotypes grown under tropical condition.

    Science.gov (United States)

    Usman, Magaji G; Rafii, Mohd Y; Martini, Mohammad Y; Oladosu, Yusuff; Kashiani, Pedram

    2017-03-01

    Studies on genotypic and phenotypic correlations among characters of crop plants are useful in planning, evaluating and setting selection criteria for the desired characters in a breeding program. The present study aimed to estimate the phenotypic correlation coefficients among yield and yield attributed characters and to work out the direct and indirect effects of yield-related characters on yield per plant using path coefficient analysis. Twenty-six genotypes of chili pepper were laid out in a randomized complete block design with three replications. Yield per plant showed positive and highly significant (P ≤ 0.01) correlations with most of the characters studied at both the phenotypic and genotypic levels. By contrast, disease incidence and days to flowering showed a significant negative association with yield. Fruit weight and number of fruits exerted positive direct effect on yield and also had a positive and significant (P ≤ 0.01) correlation with yield per plant. However, fruit length showed a low negative direct effect with a strong and positive indirect effect through fruit weight on yield and had a positive and significant association with yield. Longer fruits, heavy fruits and a high number of fruits are variables that are related to higher yields of chili pepper under tropical conditions and hence could be used as a reliable indicator in indirect selection for yield. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  4. Frequency spectrum analysis of finger photoplethysmographic waveform variability during haemodialysis.

    Science.gov (United States)

    Javed, Faizan; Middleton, Paul M; Malouf, Philip; Chan, Gregory S H; Savkin, Andrey V; Lovell, Nigel H; Steel, Elizabeth; Mackie, James

    2010-09-01

    This study investigates the peripheral circulatory and autonomic response to volume withdrawal in haemodialysis based on spectral analysis of photoplethysmographic waveform variability (PPGV). Frequency spectrum analysis was performed on the baseline and pulse amplitude variabilities of the finger infrared photoplethysmographic (PPG) waveform and on heart rate variability extracted from the ECG signal collected from 18 kidney failure patients undergoing haemodialysis. Spectral powers were calculated from the low frequency (LF, 0.04-0.145 Hz) and high frequency (HF, 0.145-0.45 Hz) bands. In eight stable fluid overloaded patients (fluid removal of >2 L) not on alpha blockers, progressive reduction in relative blood volume during haemodialysis resulted in significant increase in LF and HF powers of PPG baseline and amplitude variability (P analysis of finger PPGV may provide valuable information on the autonomic vascular response to blood volume reduction in haemodialysis, and can be potentially utilized as a non-invasive tool for assessing peripheral circulatory control during routine dialysis procedure.

  5. Hydrologic flow path development varies by aspect during spring snowmelt in complex subalpine terrain

    Science.gov (United States)

    Webb, Ryan W.; Fassnacht, Steven R.; Gooseff, Michael N.

    2018-01-01

    In many mountainous regions around the world, snow and soil moisture are key components of the hydrologic cycle. Preferential flow paths of snowmelt water through snow have been known to occur for years with few studies observing the effect on soil moisture. In this study, statistical analysis of the topographical and hydrological controls on the spatiotemporal variability of snow water equivalent (SWE) and soil moisture during snowmelt was undertaken at a subalpine forested setting with north, south, and flat aspects as a seasonally persistent snowpack melts. We investigated if evidence of preferential flow paths in snow can be observed and the effect on soil moisture through measurements of snow water equivalent and near-surface soil moisture, observing how SWE and near-surface soil moisture vary on hillslopes relative to the toes of hillslopes and flat areas. We then compared snowmelt infiltration beyond the near-surface soil between flat and sloping terrain during the entire snowmelt season using soil moisture sensor profiles. This study was conducted during varying snowmelt seasons representing above-normal, relatively normal, and below-normal snow seasons in northern Colorado. Evidence is presented of preferential meltwater flow paths at the snow-soil interface on the north-facing slope causing increases in SWE downslope and less infiltration into the soil at 20 cm depth; less association is observed in the near-surface soil moisture (top 7 cm). We present a conceptualization of the meltwater flow paths that develop based on slope aspect and soil properties. The resulting flow paths are shown to divert at least 4 % of snowmelt laterally, accumulating along the length of the slope, to increase the snow water equivalent by as much as 170 % at the base of a north-facing hillslope. Results from this study show that snow acts as an extension of the vadose zone during spring snowmelt and future hydrologic investigations will benefit from studying the snow and soil

  6. A multilevel path analysis of contact frequency between social network members

    Science.gov (United States)

    van den Berg, Pauline; Arentze, Theo; Timmermans, Harry

    2012-04-01

    Recently, there has been an increasing interest in the role of social networks in spatial-choice and travel behavior. It has been acknowledged that social activities and the travel for these activities can emerge from individuals' social networks and that social activities are responsible for an important portion of travel demand. The influence of information and communication technologies (ICT's) is also important in this respect. The purpose of the paper is to examine the effects of characteristics of egos and ego-alter relationships on the frequency of social interaction by different communication modes, using multilevel path analysis. The analyses are based on social network data collected in 2008 in the Eindhoven region in the Netherlands among 116 respondents. The results indicate a complementary relationship between contact frequencies by different modes. The contact frequencies of the different modes, especially face-to-face and telephone, can also be largely explained by the ego's personal characteristics and the type of relationship and the distance between ego and alter.

  7. Decision paths in complex tasks

    Science.gov (United States)

    Galanter, Eugene

    1991-01-01

    Complex real world action and its prediction and control has escaped analysis by the classical methods of psychological research. The reason is that psychologists have no procedures to parse complex tasks into their constituents. Where such a division can be made, based say on expert judgment, there is no natural scale to measure the positive or negative values of the components. Even if we could assign numbers to task parts, we lack rules i.e., a theory, to combine them into a total task representation. We compare here two plausible theories for the amalgamation of the value of task components. Both of these theories require a numerical representation of motivation, for motivation is the primary variable that guides choice and action in well-learned tasks. We address this problem of motivational quantification and performance prediction by developing psychophysical scales of the desireability or aversiveness of task components based on utility scaling methods (Galanter 1990). We modify methods used originally to scale sensory magnitudes (Stevens and Galanter 1957), and that have been applied recently to the measure of task 'workload' by Gopher and Braune (1984). Our modification uses utility comparison scaling techniques which avoid the unnecessary assumptions made by Gopher and Braune. Formula for the utility of complex tasks based on the theoretical models are used to predict decision and choice of alternate paths to the same goal.

  8. The Perceptions of Temporal Path Analysis of Learners' Self-Regulation on Learning Stress and Social Relationships in Junior High School

    Science.gov (United States)

    Chang, Hsiu-Ju

    2016-01-01

    This research focus on the temporal path analysis of learning stress, test anxiety, peer stress (classmate relatedness), teacher relatedness, autonomy, and self-regulative performance in junior high school. Owing to the processes of self-determination always combines several negotiations with the interactive perceptions of personal experiences and…

  9. Shortest Paths and Vehicle Routing

    DEFF Research Database (Denmark)

    Petersen, Bjørn

    This thesis presents how to parallelize a shortest path labeling algorithm. It is shown how to handle Chvátal-Gomory rank-1 cuts in a column generation context. A Branch-and-Cut algorithm is given for the Elementary Shortest Paths Problem with Capacity Constraint. A reformulation of the Vehicle...... Routing Problem based on partial paths is presented. Finally, a practical application of finding shortest paths in the telecommunication industry is shown....

  10. [Dual insertion paths design characteristics and short-term clinical observation of rotational path removable partial dentures].

    Science.gov (United States)

    Li, Jian; Jiang, Ting; Li, Sai; Chen, Wei

    2013-02-18

    To investigate design methods of dual insertion paths and observe a short-term clinic overview of rotational path removable partial dentures (RPDs). In the study, 40 patients with partial edentulous arches were included and divided into two groups. The patients in group one were restored with rotational path RPDs (10 Kennedy class III and 10 Kennedy class IV respectively). The patients in group two (20 patients), whose edentulous area was matched with the patients' in group one, were restored with the linear path RPDs. After surveying and simulative preparation on diagnostic casts, the basic laws of designing rotational path RPDs were summarized. The oral preparation was accurately performed under the guidance of indices made on diagnostic casts after simulative preparation. The 40 dentures were recalled two weeks and one year after the insertion. The evaluations of the clinic outcome, including retention, stability, mastication function, esthetics and wearing convenience, were marked out as good, acceptable, and poor. The comparison of the evaluation results was performed between the two groups. In the rotational path design for Kennedy class III or IV RPDs, the angles (α) of dual insertion paths should be designed within a scope, approximate 10°-15°.When the angle (α) became larger, the denture retention turned to be better, but accordingly the posterior abutments needed more preparation. In the clinical application, the first insertions of the 40 dentures were all favorably accomplished. When the rotational path RPDs were compared to linear path RPDs, the time consuming on first insertion had no statistical difference[(32±8) min and (33±8) min respectively, P>0.05]. Recalled two weeks and one year after the insertion, in the esthetics evaluation, 20 rotational path RPDs were all evaluated as "A", but only 7(two weeks after) and 6 (one year after) linear path RPDs were evaluated as "A"(P<0.05). There was no significant difference in other evaluation results

  11. Variability, heritability, character association and genetic divergence studies in M2 generation of gamma irradiated upland paddy

    International Nuclear Information System (INIS)

    Mehetre, S.S.; Patil, P.A.; Mahajan, C.R.; Shinde, R.B.

    1996-01-01

    The extent of coefficient of variation indicated that sterility percentage showed highest genotypic coefficients of variability (gcv) followed by grain yield/plant, plant height, spikelets/plant and tillers/plant, which proved existence of high genetic variability in induced varieties. High genetic estimates were recorded in all the characters studied. High genetic advance was observed in plant height and spikelets/panicle. Path coefficient analysis revealed that days to 50% flowering and days to maturity had largest positive direct effect on grain yield in induced varieties. (author). 10 refs., 3 tabs

  12. Genetic variability, correlation and path analysis in sponge gourd ...

    African Journals Online (AJOL)

    Windows-7

    2013-02-06

    Feb 6, 2013 ... the Middle East and India, China, Japan and Malaysia. (Porterfield, 1955). Sponge gourd is native to Tropical. Asia, probably India and South East Asia. The tender fruit is used as vegetable which is easily digestible and increase appetite when consumed (Okusanya et al.,. 1981). Besides being a vegetable ...

  13. Defending Tor from Network Adversaries: A Case Study of Network Path Prediction

    Directory of Open Access Journals (Sweden)

    Juen Joshua

    2015-06-01

    Full Text Available The Tor anonymity network has been shown vulnerable to traffic analysis attacks by autonomous systems (ASes and Internet exchanges (IXes, which can observe different overlay hops belonging to the same circuit. We evaluate whether network path prediction techniques provide an accurate picture of the threat from such adversaries, and whether they can be used to avoid this threat. We perform a measurement study by collecting 17.2 million traceroutes from Tor relays to destinations around the Internet. We compare the collected traceroute paths to predicted paths using state-of-the-art path inference techniques. We find that traceroutes present a very different picture, with the set of ASes seen in the traceroute path differing from the predicted path 80% of the time. We also consider the impact that prediction errors have on Tor security. Using a simulator to choose paths over a week, our traceroutes indicate a user has nearly a 100% chance of at least one compromise in a week with 11% of total paths containing an AS compromise and less than 1% containing an IX compromise when using default Tor selection. We find modifying the path selection to choose paths predicted to be safe lowers total paths with an AS compromise to 0.14% but still presents a 5–11% chance of at least one compromise in a week while making 5% of paths fail, with 96% of failures due to false positives in path inferences. Our results demonstrate more measurement and better path prediction is necessary to mitigate the risk of AS and IX adversaries to Tor.

  14. Path planning in changeable environments

    NARCIS (Netherlands)

    Nieuwenhuisen, D.

    2007-01-01

    This thesis addresses path planning in changeable environments. In contrast to traditional path planning that deals with static environments, in changeable environments objects are allowed to change their configurations over time. In many cases, path planning algorithms must facilitate quick

  15. Dispositional Variables and Work-Family Conflict: A Meta-Analysis

    Science.gov (United States)

    Allen, Tammy D.; Johnson, Ryan C.; Saboe, Kristin N.; Cho, Eunae; Dumani, Soner; Evans, Sarah

    2012-01-01

    Meta-analysis was used to comprehensively summarize the relationship between dispositional variables and both directions of work-family conflict. The largest effects detected were those associated with negative affect, neuroticism, and self-efficacy; all were in expected directions. In general, negative trait-based variables (e.g., negative affect…

  16. Tracing Technological Development Trajectories: A Genetic Knowledge Persistence-Based Main Path Approach.

    Directory of Open Access Journals (Sweden)

    Hyunseok Park

    Full Text Available The aim of this paper is to propose a new method to identify main paths in a technological domain using patent citations. Previous approaches for using main path analysis have greatly improved our understanding of actual technological trajectories but nonetheless have some limitations. They have high potential to miss some dominant patents from the identified main paths; nonetheless, the high network complexity of their main paths makes qualitative tracing of trajectories problematic. The proposed method searches backward and forward paths from the high-persistence patents which are identified based on a standard genetic knowledge persistence algorithm. We tested the new method by applying it to the desalination and the solar photovoltaic domains and compared the results to output from the same domains using a prior method. The empirical results show that the proposed method can dramatically reduce network complexity without missing any dominantly important patents. The main paths identified by our approach for two test cases are almost 10x less complex than the main paths identified by the existing approach. The proposed approach identifies all dominantly important patents on the main paths, but the main paths identified by the existing approach miss about 20% of dominantly important patents.

  17. Variable School Start Times and Middle School Student's Sleep Health and Academic Performance.

    Science.gov (United States)

    Lewin, Daniel S; Wang, Guanghai; Chen, Yao I; Skora, Elizabeth; Hoehn, Jessica; Baylor, Allison; Wang, Jichuan

    2017-08-01

    Improving sleep health among adolescents is a national health priority and implementing healthy school start times (SSTs) is an important strategy to achieve these goals. This study leveraged the differences in middle school SST in a large district to evaluate associations between SST, sleep health, and academic performance. This cross-sectional study draws data from a county-wide surveillance survey. Participants were three cohorts of eighth graders (n = 26,440). The school district is unique because SST ranged from 7:20 a.m. to 8:10 a.m. Path analysis and probit regression were used to analyze associations between SST and self-report measures of weekday sleep duration, grades, and homework controlling for demographic variables (sex, race, and socioeconomic status). The independent contributions of SST and sleep duration to academic performance were also analyzed. Earlier SST was associated with decreased sleep duration (χ 2  = 173, p academic performance, and academic effort. Path analysis models demonstrated the independent contributions of sleep duration, SST, and variable effects for demographic variables. This is the first study to evaluate the independent contributions of SST and sleep to academic performance in a large sample of middle school students. Deficient sleep was prevalent, and the earliest SST was associated with decrements in sleep and academics. These findings support the prioritization of policy initiatives to implement healthy SST for younger adolescents and highlight the importance of sleep health education disparities among race and gender groups. Copyright © 2017 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  18. Effect of State-Specific Factors on Acquisition Path Ranking

    International Nuclear Information System (INIS)

    Vincze, A.; Nemeth, A.

    2015-01-01

    The ''directed graph analysis'' has been shown to be a promising methodology to implement acquisition path analysis by the IAEA to support the State evaluation process. Based on this methodology a material flow network model has been developed under the Hungarian Support Programme to the IAEA, in which materials in different chemical and physical form can flow through pipes representing declared processes, material transports, diversions or undeclared processes. The ranking of the resulting acquisition paths of the analysis is a key step to facilitate the determination of technical objectives and the planning of safeguards implementation on State-level. These are determined by the attributes of the processes included into the graph and different state-specific factors. In this paper different set of attributes, State-specific factors and their functional combination will be tested for hypothetical case studies. (author)

  19. Iterative Strain-Gage Balance Calibration Data Analysis for Extended Independent Variable Sets

    Science.gov (United States)

    Ulbrich, Norbert Manfred

    2011-01-01

    A new method was developed that makes it possible to use an extended set of independent calibration variables for an iterative analysis of wind tunnel strain gage balance calibration data. The new method permits the application of the iterative analysis method whenever the total number of balance loads and other independent calibration variables is greater than the total number of measured strain gage outputs. Iteration equations used by the iterative analysis method have the limitation that the number of independent and dependent variables must match. The new method circumvents this limitation. It simply adds a missing dependent variable to the original data set by using an additional independent variable also as an additional dependent variable. Then, the desired solution of the regression analysis problem can be obtained that fits each gage output as a function of both the original and additional independent calibration variables. The final regression coefficients can be converted to data reduction matrix coefficients because the missing dependent variables were added to the data set without changing the regression analysis result for each gage output. Therefore, the new method still supports the application of the two load iteration equation choices that the iterative method traditionally uses for the prediction of balance loads during a wind tunnel test. An example is discussed in the paper that illustrates the application of the new method to a realistic simulation of temperature dependent calibration data set of a six component balance.

  20. The role of critical ethnic awareness and social support in the discrimination-depression relationship among Asian Americans: path analysis.

    Science.gov (United States)

    Kim, Isok

    2014-01-01

    This study used a path analytic technique to examine associations among critical ethnic awareness, racial discrimination, social support, and depressive symptoms. Using a convenience sample from online survey of Asian American adults (N = 405), the study tested 2 main hypotheses: First, based on the empowerment theory, critical ethnic awareness would be positively associated with racial discrimination experience; and second, based on the social support deterioration model, social support would partially mediate the relationship between racial discrimination and depressive symptoms. The result of the path analysis model showed that the proposed path model was a good fit based on global fit indices, χ²(2) = 4.70, p = .10; root mean square error of approximation = 0.06; comparative fit index = 0.97; Tucker-Lewis index = 0.92; and standardized root mean square residual = 0.03. The examinations of study hypotheses demonstrated that critical ethnic awareness was directly associated (b = .11, p Asian Americans. This study highlights the usefulness of the critical ethnic awareness concept as a way to better understand how Asian Americans might perceive and recognize racial discrimination experiences in relation to its mental health consequences.

  1. The Effects of Visual Attention Span and Phonological Decoding in Reading Comprehension in Dyslexia: A Path Analysis

    OpenAIRE

    Chen, C.; Schneps, M.; Masyn, K.; Thomson, J.

    2016-01-01

    Increasing evidence has shown visual attention span to be a factor, distinct from phonological skills, that explains single-word identification (pseudo-word/word reading) performance in dyslexia. Yet, little is known about how well visual attention span explains text comprehension. Observing reading comprehension in a sample of 105 high school students with dyslexia, we used a pathway analysis to examine the direct and indirect path between visual attention span and reading comprehension whil...

  2. Mean free path of nucleons in a Fermi gas at finite temperature

    International Nuclear Information System (INIS)

    Collins, M.T.; Griffin, J.J.

    1980-01-01

    The mean free path of a nucleon in a nuclear Fermi gas at finite temperature is calculated by utilizing the free nucleon-nucleon cross section modified to suppress final states excluded by the Pauli principle. The results agree with an earlier zero-temperature calculation but yield substantially smaller values than a previous finite-temperature analysis. The Fermi gas mean free paths are some two to four times shorter than those implied by phenomenological imaginary optical potentials, suggesting that the present Fermi gas model fails to adequately describe the physical processes determining the mean free path. Even so, the present results, taken as lower bounds on te mean free path, require temperatures of some 4.5 MeV before the mean free path of bound nucleons becomes as short as the nuclear diameter. It follows that very high excitation energies are prerequisite to any short mean free path assumption in nuclear heavy-ion collisions. (orig.)

  3. On the analysis of condylar path versus real motion of the temporomandibular joint: application for Sicat Function.

    Science.gov (United States)

    Kordaß, Bernd; Ruge, Sebastian

    2015-01-01

    Analysis of temporomandibular joint (TMJ) function using condylar path tracings is a challenge in functionally oriented dentistry. In most cases, reference points on the skin surface over the TMJ region are defined as "arbitrary", "individual" or "kinematic" condylar hinge axis points, which are displayed as "condylar paths" in motion. To what extent these reference points represent the actual condylar paths in each individual patient is ultimately unclear because the geometric relationship of the actual condyle to the selected reference point is usually unknown. Depending on the location of the point on the condyle and the centers of rotation of mandibular movement, these trajectories can vary greatly during combined rotational and sliding movements (eg, opening and closing movements of the mandible); this represents a grid of points located in the vicinity of the TMJ. To record the actual condylar path as the movement trajectory of a given point (eg, the condylar center), technological solutions are needed with which to link the tracing technology with the appropriate imaging technology capable of scanning the condyle, including the points of interest, and displaying them in real dynamic motion. Sicat Function (Sicat, D-Bonn) is such a solution. Sicat Function links cone beam computed tomography (CBCT) scans (made using the Galileos CBCT scanner; Sirona, Bensheim, Germany) with ultrasound-based, three-dimensional (3D) functional jaw movement recordings of the mandible (made using the JMT+ Jaw Motion Tracker; Sicat, Bonn, Germany). Digital images of the dental arches acquired with the intraoral scanner Cerec system (Sirona) can also be superimposed. This results in the generation of a 3D model of the bony mandible, including the TMJ, which reproduces the 3D real dynamic movement of the condyles simultaneously with that of the condylar paths at defined points (with the condylar centers being a particular point of interest). Sicat Function is an integrated, digital

  4. Nonlinear Analysis of an Unstable Bench Press Bar Path and Muscle Activation.

    Science.gov (United States)

    Lawrence, Michael A; Leib, Daniel J; Ostrowski, Stephanie J; Carlson, Lara A

    2017-05-01

    Lawrence, MA, Leib, DJ, Ostrowski, SJ, and Carlson, LA. Nonlinear analysis of an unstable bench press bar path and muscle activation. J Strength Cond Res 31(5): 1206-1211, 2017-Unstable resistance exercises are typically performed to improve the ability of stabilizing muscles to maintain joint integrity under a load. The purpose of this study was to examine the effects of an unstable load (as provided by a flexible barbell and a load suspended by elastic bands) on the bar path, the primary musculature, and stabilizing musculature while bench pressing using nonlinear analyses. Fifteen resistance-trained men (age 24.2 ± 2.7 years, mass 84.1 ± 12.0 kg, height 1.77 ± 0.05 m, 9.9 ± 3.4 years of lifting experience, and bench press 1 repetition maximum (RM) 107.5 ± 25.9 kg) volunteered for this study. Subjects pressed 2 sets of 5 repetitions in both stable (total load 75% 1RM) and unstable (total load 60% 1RM) conditions using a standard barbell and a flexible Earthquake bar, respectively. Surface electromyography was used to detect muscle activity of primary movers (pectoralis major, anterior deltoid, and triceps) and bar stabilizing musculature (latissimus dorsi, middle and posterior deltoid, biceps brachii, and upper trapezius). During the unstable condition, the bar moved in more ways and was less predictable in the mediolateral and anteroposterior directions. However, the muscle activation patterns of all muscles were more constrained with the unstable barbell. These findings suggest that the unstable condition was more challenging to control, but subjects controlled the instability by contracting their muscles in a more stable pattern or "staying tight" throughout the exercise.

  5. Measurement-Device Independency Analysis of Continuous-Variable Quantum Digital Signature

    Directory of Open Access Journals (Sweden)

    Tao Shang

    2018-04-01

    Full Text Available With the practical implementation of continuous-variable quantum cryptographic protocols, security problems resulting from measurement-device loopholes are being given increasing attention. At present, research on measurement-device independency analysis is limited in quantum key distribution protocols, while there exist different security problems for different protocols. Considering the importance of quantum digital signature in quantum cryptography, in this paper, we attempt to analyze the measurement-device independency of continuous-variable quantum digital signature, especially continuous-variable quantum homomorphic signature. Firstly, we calculate the upper bound of the error rate of a protocol. If it is negligible on condition that all measurement devices are untrusted, the protocol is deemed to be measurement-device-independent. Then, we simplify the calculation by using the characteristics of continuous variables and prove the measurement-device independency of the protocol according to the calculation result. In addition, the proposed analysis method can be extended to other quantum cryptographic protocols besides continuous-variable quantum homomorphic signature.

  6. Variable-spot ion beam figuring

    International Nuclear Information System (INIS)

    Wu, Lixiang; Qiu, Keqiang; Fu, Shaojun

    2016-01-01

    This paper introduces a new scheme of ion beam figuring (IBF), or rather variable-spot IBF, which is conducted at a constant scanning velocity with variable-spot ion beam collimated by a variable diaphragm. It aims at improving the reachability and adaptation of the figuring process within the limits of machine dynamics by varying the ion beam spot size instead of the scanning velocity. In contrast to the dwell time algorithm in the conventional IBF, the variable-spot IBF adopts a new algorithm, which consists of the scan path programming and the trajectory optimization using pattern search. In this algorithm, instead of the dwell time, a new concept, integral etching time, is proposed to interpret the process of variable-spot IBF. We conducted simulations to verify its feasibility and practicality. The simulation results indicate the variable-spot IBF is a promising alternative to the conventional approach.

  7. Path integrals on curved manifolds

    International Nuclear Information System (INIS)

    Grosche, C.; Steiner, F.

    1987-01-01

    A general framework for treating path integrals on curved manifolds is presented. We also show how to perform general coordinate and space-time transformations in path integrals. The main result is that one has to subtract a quantum correction ΔV ∝ ℎ 2 from the classical Lagrangian L, i.e. the correct effective Lagrangian to be used in the path integral is L eff = L-ΔV. A general prescription for calculating the quantum correction ΔV is given. It is based on a canonical approach using Weyl-ordering and the Hamiltonian path integral defined by the midpoint prescription. The general framework is illustrated by several examples: The d-dimensional rotator, i.e. the motion on the sphere S d-1 , the path integral in d-dimensional polar coordinates, the exact treatment of the hydrogen atom in R 2 and R 3 by performing a Kustaanheimo-Stiefel transformation, the Langer transformation and the path integral for the Morse potential. (orig.)

  8. Analysis of Dynamic Characteristics of Portal Frame with Variable Section

    Directory of Open Access Journals (Sweden)

    Hao Jianing

    2016-01-01

    Full Text Available Combined with a portal frame design, by the use of finite element software ANSYS, the finite element model of single specimens of portal rigid frame and the overall portal rigid frame building are established. portal rigid frame’s beam and column is variable cross section. Through the modal analysis, comparative analysis of the frequency and vibration type of the radiolabeling specimens and finite element model of the whole, for the further development of variable cross-section portal rigid frame of earthquake and wind vibration analysis lay the foundation.

  9. Stochastic control with rough paths

    International Nuclear Information System (INIS)

    Diehl, Joscha; Friz, Peter K.; Gassiat, Paul

    2017-01-01

    We study a class of controlled differential equations driven by rough paths (or rough path realizations of Brownian motion) in the sense of Lyons. It is shown that the value function satisfies a HJB type equation; we also establish a form of the Pontryagin maximum principle. Deterministic problems of this type arise in the duality theory for controlled diffusion processes and typically involve anticipating stochastic analysis. We make the link to old work of Davis and Burstein (Stoch Stoch Rep 40:203–256, 1992) and then prove a continuous-time generalization of Roger’s duality formula [SIAM J Control Optim 46:1116–1132, 2007]. The generic case of controlled volatility is seen to give trivial duality bounds, and explains the focus in Burstein–Davis’ (and this) work on controlled drift. Our study of controlled rough differential equations also relates to work of Mazliak and Nourdin (Stoch Dyn 08:23, 2008).

  10. Stochastic control with rough paths

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, Joscha [University of California San Diego (United States); Friz, Peter K., E-mail: friz@math.tu-berlin.de [TU & WIAS Berlin (Germany); Gassiat, Paul [CEREMADE, Université Paris-Dauphine, PSL Research University (France)

    2017-04-15

    We study a class of controlled differential equations driven by rough paths (or rough path realizations of Brownian motion) in the sense of Lyons. It is shown that the value function satisfies a HJB type equation; we also establish a form of the Pontryagin maximum principle. Deterministic problems of this type arise in the duality theory for controlled diffusion processes and typically involve anticipating stochastic analysis. We make the link to old work of Davis and Burstein (Stoch Stoch Rep 40:203–256, 1992) and then prove a continuous-time generalization of Roger’s duality formula [SIAM J Control Optim 46:1116–1132, 2007]. The generic case of controlled volatility is seen to give trivial duality bounds, and explains the focus in Burstein–Davis’ (and this) work on controlled drift. Our study of controlled rough differential equations also relates to work of Mazliak and Nourdin (Stoch Dyn 08:23, 2008).

  11. Capturing heterogeneity in gene expression studies by surrogate variable analysis.

    Directory of Open Access Journals (Sweden)

    Jeffrey T Leek

    2007-09-01

    Full Text Available It has unambiguously been shown that genetic, environmental, demographic, and technical factors may have substantial effects on gene expression levels. In addition to the measured variable(s of interest, there will tend to be sources of signal due to factors that are unknown, unmeasured, or too complicated to capture through simple models. We show that failing to incorporate these sources of heterogeneity into an analysis can have widespread and detrimental effects on the study. Not only can this reduce power or induce unwanted dependence across genes, but it can also introduce sources of spurious signal to many genes. This phenomenon is true even for well-designed, randomized studies. We introduce "surrogate variable analysis" (SVA to overcome the problems caused by heterogeneity in expression studies. SVA can be applied in conjunction with standard analysis techniques to accurately capture the relationship between expression and any modeled variables of interest. We apply SVA to disease class, time course, and genetics of gene expression studies. We show that SVA increases the biological accuracy and reproducibility of analyses in genome-wide expression studies.

  12. Qualification paths of adult educators in Sweden and Denmark

    DEFF Research Database (Denmark)

    Andersson, Per; Köpsén, Susanne; Larson, Anne

    2013-01-01

    fields of education and training. In this study, we analyse the qualification paths, or learning trajectories, of prospective adult educators in Sweden and Denmark. The analysis is based on narrative interviews with 29 students in training to become adult educators. The career paths of adult educators...... are often long and winding roads. Becoming an adult educator could be their primary desire, but it could also be their ‘Plan B’, a second choice. Individual motives and external demands interact in the professionalisation process. A shift in focus from teaching subject and methods to teaching context...... and the relation to the learners is part of the professional development. Finally, we argue that both academic studies and hands-on work in the adult education community are crucial parts of the adult educator’s qualification path....

  13. Career Path Suggestion using String Matching and Decision Trees

    Science.gov (United States)

    Nagpal, Akshay; P. Panda, Supriya

    2015-05-01

    High school and college graduates seemingly are often battling for the courses they should major in order to achieve their target career. In this paper, we worked on suggesting a career path to a graduate to reach his/her dream career given the current educational status. Firstly, we collected the career data of professionals and academicians from various career fields and compiled the data set by using the necessary information from the data. Further, this was used as the basis to suggest the most appropriate career path for the person given his/her current educational status. Decision trees and string matching algorithms were employed to suggest the appropriate career path for a person. Finally, an analysis of the result has been done directing to further improvements in the model.

  14. Welding Robot Collision-Free Path Optimization

    Directory of Open Access Journals (Sweden)

    Xuewu Wang

    2017-02-01

    Full Text Available Reasonable welding path has a significant impact on welding efficiency, and a collision-free path should be considered first in the process of welding robot path planning. The shortest path length is considered as an optimization objective, and obstacle avoidance is considered as the constraint condition in this paper. First, a grid method is used as a modeling method after the optimization objective is analyzed. For local collision-free path planning, an ant colony algorithm is selected as the search strategy. Then, to overcome the shortcomings of the ant colony algorithm, a secondary optimization is presented to improve the optimization performance. Finally, the particle swarm optimization algorithm is used to realize global path planning. Simulation results show that the desired welding path can be obtained based on the optimization strategy.

  15. Girsanov reweighting for path ensembles and Markov state models

    Science.gov (United States)

    Donati, L.; Hartmann, C.; Keller, B. G.

    2017-06-01

    The sensitivity of molecular dynamics on changes in the potential energy function plays an important role in understanding the dynamics and function of complex molecules. We present a method to obtain path ensemble averages of a perturbed dynamics from a set of paths generated by a reference dynamics. It is based on the concept of path probability measure and the Girsanov theorem, a result from stochastic analysis to estimate a change of measure of a path ensemble. Since Markov state models (MSMs) of the molecular dynamics can be formulated as a combined phase-space and path ensemble average, the method can be extended to reweight MSMs by combining it with a reweighting of the Boltzmann distribution. We demonstrate how to efficiently implement the Girsanov reweighting in a molecular dynamics simulation program by calculating parts of the reweighting factor "on the fly" during the simulation, and we benchmark the method on test systems ranging from a two-dimensional diffusion process and an artificial many-body system to alanine dipeptide and valine dipeptide in implicit and explicit water. The method can be used to study the sensitivity of molecular dynamics on external perturbations as well as to reweight trajectories generated by enhanced sampling schemes to the original dynamics.

  16. Effects of Per-Pixel Variability on Uncertainties in Bathymetric Retrievals from High-Resolution Satellite Images

    Directory of Open Access Journals (Sweden)

    Elizabeth J. Botha

    2016-05-01

    Full Text Available Increased sophistication of high spatial resolution multispectral satellite sensors provides enhanced bathymetric mapping capability. However, the enhancements are counter-acted by per-pixel variability in sunglint, atmospheric path length and directional effects. This case-study highlights retrieval errors from images acquired at non-optimal geometrical combinations. The effects of variations in the environmental noise on water surface reflectance and the accuracy of environmental variable retrievals were quantified. Two WorldView-2 satellite images were acquired, within one minute of each other, with Image 1 placed in a near-optimal sun-sensor geometric configuration and Image 2 placed close to the specular point of the Bidirectional Reflectance Distribution Function (BRDF. Image 2 had higher total environmental noise due to increased surface glint and higher atmospheric path-scattering. Generally, depths were under-estimated from Image 2, compared to Image 1. A partial improvement in retrieval error after glint correction of Image 2 resulted in an increase of the maximum depth to which accurate depth estimations were returned. This case-study indicates that critical analysis of individual images, accounting for the entire sun elevation and azimuth and satellite sensor pointing and geometry as well as anticipated wave height and direction, is required to ensure an image is fit for purpose for aquatic data analysis.

  17. Social comparison processes and catastrophising in fibromyalgia: A path analysis.

    Science.gov (United States)

    Cabrera-Perona, V; Buunk, A P; Terol-Cantero, M C; Quiles-Marcos, Y; Martín-Aragón, M

    2017-06-01

    In addition to coping strategies, social comparison may play a role in illness adjustment. However, little is known about the role of contrast and identification in social comparison in adaptation to fibromyalgia. To evaluate through a path analysis in a sample of fibromyalgia patients, the association between identification and contrast in social comparison, catastrophising and specific health outcomes (fibromyalgia illness impact and psychological distress). 131 Spanish fibromyalgia outpatients (mean age: 50.15, SD = 11.1) filled out a questionnaire. We present a model that explained 33% of the variance in catastrophising by direct effects of more use of upward contrast and downward identification. In addition, 35% of fibromyalgia illness impact variance was explained by less upward identification, more upward contrast and more catastrophising and 42% of the variance in psychological distress by a direct effect of more use of upward contrast together with higher fibromyalgia illness impact. We suggest that intervention programmes with chronic pain and fibromyalgia patients should focus on enhancing the use of upward identification in social comparison, and on minimising the use of upward contrast and downward identification in social comparison.

  18. Visual scan-path analysis with feature space transient fixation moments

    Science.gov (United States)

    Dempere-Marco, Laura; Hu, Xiao-Peng; Yang, Guang-Zhong

    2003-05-01

    The study of eye movements provides useful insight into the cognitive processes underlying visual search tasks. The analysis of the dynamics of eye movements has often been approached from a purely spatial perspective. In many cases, however, it may not be possible to define meaningful or consistent dynamics without considering the features underlying the scan paths. In this paper, the definition of the feature space has been attempted through the concept of visual similarity and non-linear low dimensional embedding, which defines a mapping from the image space into a low dimensional feature manifold that preserves the intrinsic similarity of image patterns. This has enabled the definition of perceptually meaningful features without the use of domain specific knowledge. Based on this, this paper introduces a new concept called Feature Space Transient Fixation Moments (TFM). The approach presented tackles the problem of feature space representation of visual search through the use of TFM. We demonstrate the practical values of this concept for characterizing the dynamics of eye movements in goal directed visual search tasks. We also illustrate how this model can be used to elucidate the fundamental steps involved in skilled search tasks through the evolution of transient fixation moments.

  19. Spreading paths in partially observed social networks

    Science.gov (United States)

    Onnela, Jukka-Pekka; Christakis, Nicholas A.

    2012-03-01

    Understanding how and how far information, behaviors, or pathogens spread in social networks is an important problem, having implications for both predicting the size of epidemics, as well as for planning effective interventions. There are, however, two main challenges for inferring spreading paths in real-world networks. One is the practical difficulty of observing a dynamic process on a network, and the other is the typical constraint of only partially observing a network. Using static, structurally realistic social networks as platforms for simulations, we juxtapose three distinct paths: (1) the stochastic path taken by a simulated spreading process from source to target; (2) the topologically shortest path in the fully observed network, and hence the single most likely stochastic path, between the two nodes; and (3) the topologically shortest path in a partially observed network. In a sampled network, how closely does the partially observed shortest path (3) emulate the unobserved spreading path (1)? Although partial observation inflates the length of the shortest path, the stochastic nature of the spreading process also frequently derails the dynamic path from the shortest path. We find that the partially observed shortest path does not necessarily give an inflated estimate of the length of the process path; in fact, partial observation may, counterintuitively, make the path seem shorter than it actually is.

  20. Spreading paths in partially observed social networks.

    Science.gov (United States)

    Onnela, Jukka-Pekka; Christakis, Nicholas A

    2012-03-01

    Understanding how and how far information, behaviors, or pathogens spread in social networks is an important problem, having implications for both predicting the size of epidemics, as well as for planning effective interventions. There are, however, two main challenges for inferring spreading paths in real-world networks. One is the practical difficulty of observing a dynamic process on a network, and the other is the typical constraint of only partially observing a network. Using static, structurally realistic social networks as platforms for simulations, we juxtapose three distinct paths: (1) the stochastic path taken by a simulated spreading process from source to target; (2) the topologically shortest path in the fully observed network, and hence the single most likely stochastic path, between the two nodes; and (3) the topologically shortest path in a partially observed network. In a sampled network, how closely does the partially observed shortest path (3) emulate the unobserved spreading path (1)? Although partial observation inflates the length of the shortest path, the stochastic nature of the spreading process also frequently derails the dynamic path from the shortest path. We find that the partially observed shortest path does not necessarily give an inflated estimate of the length of the process path; in fact, partial observation may, counterintuitively, make the path seem shorter than it actually is.

  1. An empirical typology of hospital nurses' individual learning paths.

    Science.gov (United States)

    Poell, Rob F; Van der Krogt, Ferd J

    2014-03-01

    A relatively new theoretical concept is proposed in this paper, namely, the individual learning path. Learning paths are created by individual employees and comprise a set of learning-relevant activities that are both coherent as a whole and meaningful to them. To explore the empirical basis of this theoretical concept. A qualitative study involving semi-structured interviews. Two academic medical centers (university hospitals) and two general hospitals in the Netherlands. A total of 89 nurses were involved in the study. Semi-structured interviews were analyzed qualitatively; cluster analysis was then performed on quantified data from the interviews. Four types of learning path emerged, namely, the formal-external, self-directed, social-emotional, and information-oriented learning paths. The relatively new theoretical concept of an individual learning path can be observed in practice and a number of different learning-path types can be distinguished. Nurses were found to create their own learning paths, that is, select a theme that is relevant primarily to themselves, conduct a variety of learning activities around this theme, participate in social contexts that might help them, and mobilize learning facilities provided by their organization. These activities go way beyond the notion of employees as self-directed learners merely in a didactic sense (establishing learning goals, choosing the right learning activities for these goals, evaluating to what extent their goals have been met as a result). The findings can be interpreted as evidence of employees acting strategically when it comes to their professional development. Providers of continuing professional education/development need to take this into account. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Symbolic PathFinder v7

    DEFF Research Database (Denmark)

    Luckow, Kasper Søe; Păsăreanu, Corina

    2014-01-01

    We describe Symbolic PathFinder v7 in terms of its updated design addressing the changes of Java PathFinder v7 and of its new optimization when computing path conditions. Furthermore, we describe the Symbolic Execution Tree Extension; a newly added feature that allows for outputting the symbolic...... execution tree that characterizes the execution paths covered during symbolic execution. The new extension can be tailored to the needs of subsequent analyses/processing facilities, and we demonstrate this by presenting SPF-Visualizer, which is a tool for customizable visualization of the symbolic execution...

  3. Force characteristics in continuous path controlled crankpin grinding

    Science.gov (United States)

    Zhang, Manchao; Yao, Zhenqiang

    2015-03-01

    Recent research on the grinding force involved in cylindrical plunge grinding has focused mainly on steady-state conditions. Unlike in conventional external cylindrical plunge grinding, the conditions between the grinding wheel and the crankpin change periodically in path controlled grinding because of the eccentricity of the crankpin and the constant rotational speed of the crankshaft. The objective of this study is to investigate the effects of various grinding conditions on the characteristics of the grinding force during continuous path controlled grinding. Path controlled plunge grinding is conducted at a constant rotational speed using a cubic boron nitride (CBN) wheel. The grinding force is determined by measuring the torque. The experimental results show that the force and torque vary sinusoidally during dry grinding and load grinding. The variations in the results reveal that the resultant grinding force and torque decrease with higher grinding speeds and increase with higher peripheral speeds of the pin and higher grinding depths. In path controlled grinding, unlike in conventional external cylindrical plunge grinding, the axial grinding force cannot be disregarded. The speeds and speed ratios of the workpiece and wheel are also analyzed, and the analysis results show that up-grinding and down-grinding occur during the grinding process. This paper proposes a method for describing the force behavior under varied process conditions during continuous path controlled grinding, which provides a beneficial reference for describing the material removal mechanism and for optimizing continuous controlled crankpin grinding.

  4. Path-average rainfall estimation from optical extinction measurements using a large-aperture scintillometer

    NARCIS (Netherlands)

    Uijlenhoet, R.; Cohard, J.M.; Gosset, M.

    2011-01-01

    The potential of a near-infrared large-aperture boundary layer scintillometer as path-average rain gauge is investigated. The instrument was installed over a 2.4-km path in Benin as part of the African Monsoon Multidisciplinary Analysis (AMMA) Enhanced Observation Period during 2006 and 2007.

  5. Path integrals and coherent states of SU(2) and SU(1,1)

    CERN Document Server

    Inomata, Akira; Kuratsuji, Hiroshi

    1992-01-01

    The authors examine several topical subjects, commencing with a general introduction to path integrals in quantum mechanics and the group theoretical backgrounds for path integrals. Applications of harmonic analysis, polar coordinate formulation, various techniques and path integrals on SU(2) and SU(1, 1) are discussed. Soluble examples presented include particle-flux system, a pulsed oscillator, magnetic monopole, the Coulomb problem in curved space and others.The second part deals with the SU(2) coherent states and their applications. Construction and generalization of the SU(2) coherent sta

  6. Structural equation models from paths to networks

    CERN Document Server

    Westland, J Christopher

    2015-01-01

    This compact reference surveys the full range of available structural equation modeling (SEM) methodologies.  It reviews applications in a broad range of disciplines, particularly in the social sciences where many key concepts are not directly observable.  This is the first book to present SEM’s development in its proper historical context–essential to understanding the application, strengths and weaknesses of each particular method.  This book also surveys the emerging path and network approaches that complement and enhance SEM, and that will grow in importance in the near future.  SEM’s ability to accommodate unobservable theory constructs through latent variables is of significant importance to social scientists.  Latent variable theory and application are comprehensively explained, and methods are presented for extending their power, including guidelines for data preparation, sample size calculation, and the special treatment of Likert scale data.  Tables of software, methodologies and fit st...

  7. Path integral methods for the dynamics of stochastic and disordered systems

    International Nuclear Information System (INIS)

    Hertz, John A; Roudi, Yasser; Sollich, Peter

    2017-01-01

    We review some of the techniques used to study the dynamics of disordered systems subject to both quenched and fast (thermal) noise. Starting from the Martin–Siggia–Rose/Janssen–De Dominicis–Peliti path integral formalism for a single variable stochastic dynamics, we provide a pedagogical survey of the perturbative, i.e. diagrammatic, approach to dynamics and how this formalism can be used for studying soft spin models. We review the supersymmetric formulation of the Langevin dynamics of these models and discuss the physical implications of the supersymmetry. We also describe the key steps involved in studying the disorder-averaged dynamics. Finally, we discuss the path integral approach for the case of hard Ising spins and review some recent developments in the dynamics of such kinetic Ising models. (topical review)

  8. MEASURING PATH DEPENDENCY

    Directory of Open Access Journals (Sweden)

    Peter Juhasz

    2017-03-01

    Full Text Available While risk management gained popularity during the last decades even some of the basic risk types are still far out of focus. One of these is path dependency that refers to the uncertainty of how we reach a certain level of total performance over time. While decision makers are careful in accessing how their position will look like the end of certain periods, little attention is given how they will get there through the period. The uncertainty of how a process will develop across a shorter period of time is often “eliminated” by simply choosing a longer planning time interval, what makes path dependency is one of the most often overlooked business risk types. After reviewing the origin of the problem we propose and compare seven risk measures to access path. Traditional risk measures like standard deviation of sub period cash flows fail to capture this risk type. We conclude that in most cases considering the distribution of the expected cash flow effect caused by the path dependency may offer the best method, but we may need to use several measures at the same time to include all the optimisation limits of the given firm

  9. Comparison among manual instruments and PathFile and Mtwo rotary instruments to create a glide path in the root canal preparation of curved canals.

    Science.gov (United States)

    Alves, Vanessa de Oliveira; Bueno, Carlos Eduardo da Silveira; Cunha, Rodrigo Sanches; Pinheiro, Sérgio Luiz; Fontana, Carlos Eduardo; de Martin, Alexandre Sigrist

    2012-01-01

    Nickel-titanium rotary instruments reduce procedural errors and the time required to finish root canal preparation. The goal of this study was to evaluate the occurrences of apical transportation and canal aberrations produced with different instruments used to create a glide path in the preparation of curved root canals, namely manual K-files (Dentsply Maillefer, Ballaigues, Switzerland) and PathFile (Dentsply Maillefer) and Mtwo (Sweden and Martina, Padua, Italy) nickel-titanium rotary files. The mesial canals of 45 mandibular first and second molars (with curvature angles between 25° and 35°) were selected for this study. The specimens were divided randomly into 3 groups with 15 canals each, and canal preparation was performed by an endodontist using #10-15-20 K-type stainless steel manual files (group M), #13-16-19 PathFile rotary instruments (group PF), and #10-15-20 Mtwo rotary instruments (group MT). The double digital radiograph technique was used, pre- and postinstrumentation, to assess whether apical transportation and/or aberration in root canal morphology occurred. The initial and final images of the central axis of the canals were compared by superimposition through computerized analysis and with the aid of magnification. The specimens were analyzed by 3 evaluators, whose calibration was checked using the Kendall agreement test. No apical transportation or aberration in root canal morphology occurred in any of the teeth; therefore, no statistical analysis was conducted. Neither the manual instruments nor the PathFile or Mtwo rotary instruments used to create a glide path had any influence on the occurrence of apical transportation or produced any canal aberration. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  10. Evaluating methods for estimating space-time paths of individuals in calculating long-term personal exposure to air pollution

    Science.gov (United States)

    Schmitz, Oliver; Soenario, Ivan; Vaartjes, Ilonca; Strak, Maciek; Hoek, Gerard; Brunekreef, Bert; Dijst, Martin; Karssenberg, Derek

    2016-04-01

    Air pollution is one of the major concerns for human health. Associations between air pollution and health are often calculated using long-term (i.e. years to decades) information on personal exposure for each individual in a cohort. Personal exposure is the air pollution aggregated along the space-time path visited by an individual. As air pollution may vary considerably in space and time, for instance due to motorised traffic, the estimation of the spatio-temporal location of a persons' space-time path is important to identify the personal exposure. However, long term exposure is mostly calculated using the air pollution concentration at the x, y location of someone's home which does not consider that individuals are mobile (commuting, recreation, relocation). This assumption is often made as it is a major challenge to estimate space-time paths for all individuals in large cohorts, mostly because limited information on mobility of individuals is available. We address this issue by evaluating multiple approaches for the calculation of space-time paths, thereby estimating the personal exposure along these space-time paths with hyper resolution air pollution maps at national scale. This allows us to evaluate the effect of the space-time path and resulting personal exposure. Air pollution (e.g. NO2, PM10) was mapped for the entire Netherlands at a resolution of 5×5 m2 using the land use regression models developed in the European Study of Cohorts for Air Pollution Effects (ESCAPE, http://escapeproject.eu/) and the open source software PCRaster (http://www.pcraster.eu). The models use predictor variables like population density, land use, and traffic related data sets, and are able to model spatial variation and within-city variability of annual average concentration values. We approximated space-time paths for all individuals in a cohort using various aggregations, including those representing space-time paths as the outline of a persons' home or associated parcel

  11. Path integration in conical space

    International Nuclear Information System (INIS)

    Inomata, Akira; Junker, Georg

    2012-01-01

    Quantum mechanics in conical space is studied by the path integral method. It is shown that the curvature effect gives rise to an effective potential in the radial path integral. It is further shown that the radial path integral in conical space can be reduced to a form identical with that in flat space when the discrete angular momentum of each partial wave is replaced by a specific non-integral angular momentum. The effective potential is found proportional to the squared mean curvature of the conical surface embedded in Euclidean space. The path integral calculation is compatible with the Schrödinger equation modified with the Gaussian and the mean curvature. -- Highlights: ► We study quantum mechanics on a cone by the path integral approach. ► The path integral depends only on the metric and the curvature effect is built in. ► The approach is consistent with the Schrödinger equation modified by an effective potential. ► The effective potential is found to be of the “Jensen–Koppe” and “da Costa” type.

  12. Prograph Based Analysis of Single Source Shortest Path Problem with Few Distinct Positive Lengths

    Directory of Open Access Journals (Sweden)

    B. Bhowmik

    2011-08-01

    Full Text Available In this paper we propose an experimental study model S3P2 of a fast fully dynamic programming algorithm design technique in finite directed graphs with few distinct nonnegative real edge weights. The Bellman-Ford’s approach for shortest path problems has come out in various implementations. In this paper the approach once again is re-investigated with adjacency matrix selection in associate least running time. The model tests proposed algorithm against arbitrarily but positive valued weighted digraphs introducing notion of Prograph that speeds up finding the shortest path over previous implementations. Our experiments have established abstract results with the intention that the proposed algorithm can consistently dominate other existing algorithms for Single Source Shortest Path Problems. A comparison study is also shown among Dijkstra’s algorithm, Bellman-Ford algorithm, and our algorithm.

  13. Path tortuosity in everyday movements of elderly persons increases fall prediction beyond knowledge of fall history, medication use, and standardized gait and balance assessments.

    Science.gov (United States)

    Kearns, William D; Fozard, James L; Becker, Marion; Jasiewicz, Jan M; Craighead, Jeffrey D; Holtsclaw, Lori; Dion, Charles

    2012-09-01

    We hypothesized that variability in voluntary movement paths of assisted living facility (ALF) residents would be greater in the week preceding a fall compared with residents who did not fall. Prospective, observational study using telesurveillance technology. Two ALFs. The sample consisted of 69 older ALF residents (53 female) aged 76.9 (SD ± 11.9 years). Daytime movement in ALF common use areas was automatically tracked using a commercially available ultra-wideband radio real-time location sensor network with a spatial resolution of approximately 20 cm. Movement path variability (tortuosity) was gauged using fractal dimension (fractal D). A logistic regression was performed predicting movement related falls from fractal D, presence of a fall in the prior year, psychoactive medication use, and movement path length. Fallers and non-fallers were also compared on activities of daily living requiring supervision or assistance, performance on standardized static and dynamic balance, and stride velocity assessments gathered at the start of a 1-year fall observation period. Fall risk due to cognitive deficit was assessed by the Mini Mental Status Examination (MMSE), and by clinical dementia diagnoses from participant's activities of daily living health record. Logistic regression analysis revealed odds of falling increased 2.548 (P = .021) for every 0.1 increase in fractal D, and having a fall in the prior year increased odds of falling by 7.36 (P = .006). There was a trend for longer movement paths to reduce the odds of falling (OR .976 P = .08) but it was not significant. Number of psychoactive medications did not contribute significantly to fall prediction in the model. Fallers had more variable stride-to-stride velocities and required more activities of daily living assistance. High fractal D levels can be detected using commercially available telesurveillance technologies and offers a new tool for health services administrators seeking to reduce falls at their

  14. Two dimensional simplicial paths

    International Nuclear Information System (INIS)

    Piso, M.I.

    1994-07-01

    Paths on the R 3 real Euclidean manifold are defined as 2-dimensional simplicial strips which are orbits of the action of a discrete one-parameter group. It is proven that there exists at least one embedding of R 3 in the free Z-module generated by S 2 (x 0 ). The speed is defined as the simplicial derivative of the path. If mass is attached to the simplex, the free Lagrangian is proportional to the width of the path. In the continuum limit, the relativistic form of the Lagrangian is recovered. (author). 7 refs

  15. Insulin resistance and carotid intima-media thickness mediate the association between resting-state heart rate variability and executive function: A path modelling study.

    Science.gov (United States)

    Kemp, Andrew H; López, Santiago Rodríguez; Passos, Valeria M A; Bittencourt, Marcio S; Dantas, Eduardo M; Mill, José G; Ribeiro, Antonio L P; Thayer, Julian F; Bensenor, Isabela M; Lotufo, Paulo A

    2016-05-01

    Research has linked high-frequency heart rate variability (HF-HRV) to cognitive function. The present study adopts a modern path modelling approach to understand potential causal pathways that may underpin this relationship. Here we examine the association between resting-state HF-HRV and executive function in a large sample of civil servants from Brazil (N=8114) recruited for the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). HF-HRV was calculated from 10-min resting-state electrocardiograms. Executive function was assessed using the trail-making test (version B). Insulin resistance (a marker of type 2 diabetes mellitus) and carotid intima-media thickness (subclinical atherosclerosis) mediated the relationship between HRV and executive function in seriatim. A limitation of the present study is its cross-sectional design; therefore, conclusions must be confirmed in longitudinal study. Nevertheless, findings support that possibility that HRV provides a 'spark' that initiates a cascade of adverse downstream effects that subsequently leads to cognitive impairment. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Analysis of Dynamic Characteristics of Portal Frame with Variable Section

    OpenAIRE

    Hao Jianing

    2016-01-01

    Combined with a portal frame design, by the use of finite element software ANSYS, the finite element model of single specimens of portal rigid frame and the overall portal rigid frame building are established. portal rigid frame’s beam and column is variable cross section. Through the modal analysis, comparative analysis of the frequency and vibration type of the radiolabeling specimens and finite element model of the whole, for the further development of variable cross-section portal rigid f...

  17. Jarzynski equality in the context of maximum path entropy

    Science.gov (United States)

    González, Diego; Davis, Sergio

    2017-06-01

    In the global framework of finding an axiomatic derivation of nonequilibrium Statistical Mechanics from fundamental principles, such as the maximum path entropy - also known as Maximum Caliber principle -, this work proposes an alternative derivation of the well-known Jarzynski equality, a nonequilibrium identity of great importance today due to its applications to irreversible processes: biological systems (protein folding), mechanical systems, among others. This equality relates the free energy differences between two equilibrium thermodynamic states with the work performed when going between those states, through an average over a path ensemble. In this work the analysis of Jarzynski's equality will be performed using the formalism of inference over path space. This derivation highlights the wide generality of Jarzynski's original result, which could even be used in non-thermodynamical settings such as social systems, financial and ecological systems.

  18. Openness to Experience and Night-Sky Watching Interest as Predictors of Reading for Pleasure: Path Analysis of a Mediation Model

    Science.gov (United States)

    Kelly, William E.

    2010-01-01

    The relation between reading for pleasure, night-sky watching interest, and openness to experience were examined in a sample of 129 college students. Results of a path analysis examining a mediation model indicated that the influence of night-sky interest on reading for pleasure was not mediated by the broad personality domain openness to…

  19. Analysis of explicit model predictive control for path-following control.

    Science.gov (United States)

    Lee, Junho; Chang, Hyuk-Jun

    2018-01-01

    In this paper, explicit Model Predictive Control(MPC) is employed for automated lane-keeping systems. MPC has been regarded as the key to handle such constrained systems. However, the massive computational complexity of MPC, which employs online optimization, has been a major drawback that limits the range of its target application to relatively small and/or slow problems. Explicit MPC can reduce this computational burden using a multi-parametric quadratic programming technique(mp-QP). The control objective is to derive an optimal front steering wheel angle at each sampling time so that autonomous vehicles travel along desired paths, including straight, circular, and clothoid parts, at high entry speeds. In terms of the design of the proposed controller, a method of choosing weighting matrices in an optimization problem and the range of horizons for path-following control are described through simulations. For the verification of the proposed controller, simulation results obtained using other control methods such as MPC, Linear-Quadratic Regulator(LQR), and driver model are employed, and CarSim, which reflects the features of a vehicle more realistically than MATLAB/Simulink, is used for reliable demonstration.

  20. Analysis of explicit model predictive control for path-following control

    Science.gov (United States)

    2018-01-01

    In this paper, explicit Model Predictive Control(MPC) is employed for automated lane-keeping systems. MPC has been regarded as the key to handle such constrained systems. However, the massive computational complexity of MPC, which employs online optimization, has been a major drawback that limits the range of its target application to relatively small and/or slow problems. Explicit MPC can reduce this computational burden using a multi-parametric quadratic programming technique(mp-QP). The control objective is to derive an optimal front steering wheel angle at each sampling time so that autonomous vehicles travel along desired paths, including straight, circular, and clothoid parts, at high entry speeds. In terms of the design of the proposed controller, a method of choosing weighting matrices in an optimization problem and the range of horizons for path-following control are described through simulations. For the verification of the proposed controller, simulation results obtained using other control methods such as MPC, Linear-Quadratic Regulator(LQR), and driver model are employed, and CarSim, which reflects the features of a vehicle more realistically than MATLAB/Simulink, is used for reliable demonstration. PMID:29534080

  1. A Path-Independent Forming Limit Criterion for Stamping Simulations

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  2. Cooperative organic mine avoidance path planning

    Science.gov (United States)

    McCubbin, Christopher B.; Piatko, Christine D.; Peterson, Adam V.; Donnald, Creighton R.; Cohen, David

    2005-06-01

    The JHU/APL Path Planning team has developed path planning techniques to look for paths that balance the utility and risk associated with different routes through a minefield. Extending on previous years' efforts, we investigated real-world Naval mine avoidance requirements and developed a tactical decision aid (TDA) that satisfies those requirements. APL has developed new mine path planning techniques using graph based and genetic algorithms which quickly produce near-minimum risk paths for complicated fitness functions incorporating risk, path length, ship kinematics, and naval doctrine. The TDA user interface, a Java Swing application that obtains data via Corba interfaces to path planning databases, allows the operator to explore a fusion of historic and in situ mine field data, control the path planner, and display the planning results. To provide a context for the minefield data, the user interface also renders data from the Digital Nautical Chart database, a database created by the National Geospatial-Intelligence Agency containing charts of the world's ports and coastal regions. This TDA has been developed in conjunction with the COMID (Cooperative Organic Mine Defense) system. This paper presents a description of the algorithms, architecture, and application produced.

  3. Common Virtual Path and Its Expedience for VBR Video Traffic

    Directory of Open Access Journals (Sweden)

    E. Chromy

    2008-04-01

    Full Text Available The paper deals with utilization of common Virtual Path (VP for variable bit rate (VBR video service. Video service is one of the main services for broadband networks. Research is oriented to statistical properties of common and separate VPs. Separate VP means that for each VBR traffic source one VP will be allocated. Common VP means that for multiple VBR sources one common VP is allocated. VBR video traffic source is modeled by discrete Markov chain.

  4. Expressing Solutions of the Dirac Equation in Terms of Feynman Path Integral

    CERN Document Server

    Hose, R D

    2006-01-01

    Using the separation of the variables technique, the free particle solutions of the Dirac equation in the momentum space are shown to be actually providing the definition of Delta function for the Schr dinger picture. Further, the said solution is shown to be derivable on the sole strength of geometrical argument that the Dirac equation for free particle is an equation of a plane in momentum space. During the evolution of time in the Schr dinger picture, the normal to the said Dirac equation plane is shown to be constantly changing in direction due to the uncertainty principle and thereby, leading to a zigzag path for the Dirac particle in the momentum space. Further, the time evolution of the said Delta function solutions of the Dirac equation is shown to provide Feynman integral of all such zigzag paths in the momentum space. Towards the end of the paper, Feynman path integral between two fixed spatial points in the co-ordinate space during a certain time interv! al is shown to be composed, in time sequence...

  5. Partial least squares path modeling basic concepts, methodological issues and applications

    CERN Document Server

    Noonan, Richard

    2017-01-01

    This edited book presents the recent developments in partial least squares-path modeling (PLS-PM) and provides a comprehensive overview of the current state of the most advanced research related to PLS-PM. The first section of this book emphasizes the basic concepts and extensions of the PLS-PM method. The second section discusses the methodological issues that are the focus of the recent development of the PLS-PM method. The third part discusses the real world application of the PLS-PM method in various disciplines. The contributions from expert authors in the field of PLS focus on topics such as the factor-based PLS-PM, the perfect match between a model and a mode, quantile composite-based path modeling (QC-PM), ordinal consistent partial least squares (OrdPLSc), non-symmetrical composite-based path modeling (NSCPM), modern view for mediation analysis in PLS-PM, a multi-method approach for identifying and treating unobserved heterogeneity, multigroup analysis (PLS-MGA), the assessment of the common method b...

  6. The role of experiential avoidance, psychopathology, and borderline personality features in experiencing positive emotions: a path analysis.

    Science.gov (United States)

    Jacob, Gitta A; Ower, Nicole; Buchholz, Angela

    2013-03-01

    Experiential avoidance (EA) is an important factor in maintaining different forms of psychopathology including borderline personality pathology (BPD). So far little is known about the functions of EA, BPD features and general psychopathology for positive emotions. In this study we investigated three different anticipated pathways of their influence on positive emotions. A total of 334 subjects varying in general psychopathology &/or BPD features completed an online survey including self-ratings of BPD features, psychopathology, negative and positive emotions, and EA. Measures of positive emotions included both a general self-rating (PANAS) and emotional changes induced by two positive movie clips. Data were analyzed by means of path analysis. In comparing the three path models, one model was found clearly superior: In this model, EA acts as a mediator of the influence of psychopathology, BPD features, and negative emotions in the prediction of both measures of positive emotions. EA plays a central role in maintaining lack of positive emotions. Therapeutic implications and study limitations are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. A new online secondary path modeling method for adaptive active structure vibration control

    International Nuclear Information System (INIS)

    Pu, Yuxue; Zhang, Fang; Jiang, Jinhui

    2014-01-01

    This paper proposes a new variable step size FXLMS algorithm with an auxiliary noise power scheduling strategy for online secondary path modeling. The step size for the secondary path modeling filter and the gain of auxiliary noise are varied in accordance with the parameters available directly. The proposed method has a low computational complexity. Computer simulations show that an active vibration control system with the proposed method gives much better vibration attenuation and modeling accuracy at a faster convergence rate than existing methods. National Instruments’ CompactRIO is used as an embedded processor to control simply supported beam vibration. Experimental results indicate that the vibration of the beam has been effectively attenuated. (papers)

  8. Conserved variable analysis of the marine boundary layer and air

    Indian Academy of Sciences (India)

    The present study is based on the observed features of the MBL (Marine Boundary Layer) during the Bay of Bengal and Monsoon Experiment (BOBMEX) - Pilot phase. Conserved Variable Analysis (CVA) of the conserved variables such as potential temperature, virtual potential temperature, equivalent potential temperature ...

  9. Microsatellite analysis of selected Lablab purpureus genotypes in ...

    African Journals Online (AJOL)

    cntaganda

    loaded alongside standards (3 µL, 5 µL and 10 µL) of lambda (λ) DNA and run at 70 V ..... developing primers for the crop as it has lagged behind in primer library. ... Genetic variability, character association and path analysis of pod yield and.

  10. The effect of solar and lunar currents on simultaneous phase path, group path and amplitude measurements

    International Nuclear Information System (INIS)

    Baulch, R.N.E.; Butcher, E.C.

    1984-01-01

    The solar and lunar variations in the phase path, group path and amplitude of a fixed frequency transmission were obtained at the September equinox over a slightly oblique path. The phase of the lunar semi-diurnal tide in the phase path and amplitude were similar, the maxima occurring near 0200 lunar time, whereas the group path had a maximum near 0800 lunar time. These results were compared with other results obtained near the same location. The results suggest a complex situation in the E-region, where the height of the lunar current depends on season, and also suggest that the location and distribution of the solar and lunar currents may be different. (author)

  11. Global Appearance Applied to Visual Map Building and Path Estimation Using Multiscale Analysis

    Directory of Open Access Journals (Sweden)

    Francisco Amorós

    2014-01-01

    Full Text Available In this work we present a topological map building and localization system for mobile robots based on global appearance of visual information. We include a comparison and analysis of global-appearance techniques applied to wide-angle scenes in retrieval tasks. Next, we define multiscale analysis, which permits improving the association between images and extracting topological distances. Then, a topological map-building algorithm is proposed. At first, the algorithm has information only of some isolated positions of the navigation area in the form of nodes. Each node is composed of a collection of images that covers the complete field of view from a certain position. The algorithm solves the node retrieval and estimates their spatial arrangement. With these aims, it uses the visual information captured along some routes that cover the navigation area. As a result, the algorithm builds a graph that reflects the distribution and adjacency relations between nodes (map. After the map building, we also propose a route path estimation system. This algorithm takes advantage of the multiscale analysis. The accuracy in the pose estimation is not reduced to the nodes locations but also to intermediate positions between them. The algorithms have been tested using two different databases captured in real indoor environments under dynamic conditions.

  12. Sensitivity Analysis of Weather Variables on Offsite Consequence Analysis Tools in South Korea and the United States

    Directory of Open Access Journals (Sweden)

    Min-Uk Kim

    2018-05-01

    Full Text Available We studied sensitive weather variables for consequence analysis, in the case of chemical leaks on the user side of offsite consequence analysis (OCA tools. We used OCA tools Korea Offsite Risk Assessment (KORA and Areal Location of Hazardous Atmospheres (ALOHA in South Korea and the United States, respectively. The chemicals used for this analysis were 28% ammonia (NH3, 35% hydrogen chloride (HCl, 50% hydrofluoric acid (HF, and 69% nitric acid (HNO3. The accident scenarios were based on leakage accidents in storage tanks. The weather variables were air temperature, wind speed, humidity, and atmospheric stability. Sensitivity analysis was performed using the Statistical Package for the Social Sciences (SPSS program for dummy regression analysis. Sensitivity analysis showed that impact distance was not sensitive to humidity. Impact distance was most sensitive to atmospheric stability, and was also more sensitive to air temperature than wind speed, according to both the KORA and ALOHA tools. Moreover, the weather variables were more sensitive in rural conditions than in urban conditions, with the ALOHA tool being more influenced by weather variables than the KORA tool. Therefore, if using the ALOHA tool instead of the KORA tool in rural conditions, users should be careful not to cause any differences in impact distance due to input errors of weather variables, with the most sensitive one being atmospheric stability.

  13. Sensitivity Analysis of Weather Variables on Offsite Consequence Analysis Tools in South Korea and the United States.

    Science.gov (United States)

    Kim, Min-Uk; Moon, Kyong Whan; Sohn, Jong-Ryeul; Byeon, Sang-Hoon

    2018-05-18

    We studied sensitive weather variables for consequence analysis, in the case of chemical leaks on the user side of offsite consequence analysis (OCA) tools. We used OCA tools Korea Offsite Risk Assessment (KORA) and Areal Location of Hazardous Atmospheres (ALOHA) in South Korea and the United States, respectively. The chemicals used for this analysis were 28% ammonia (NH₃), 35% hydrogen chloride (HCl), 50% hydrofluoric acid (HF), and 69% nitric acid (HNO₃). The accident scenarios were based on leakage accidents in storage tanks. The weather variables were air temperature, wind speed, humidity, and atmospheric stability. Sensitivity analysis was performed using the Statistical Package for the Social Sciences (SPSS) program for dummy regression analysis. Sensitivity analysis showed that impact distance was not sensitive to humidity. Impact distance was most sensitive to atmospheric stability, and was also more sensitive to air temperature than wind speed, according to both the KORA and ALOHA tools. Moreover, the weather variables were more sensitive in rural conditions than in urban conditions, with the ALOHA tool being more influenced by weather variables than the KORA tool. Therefore, if using the ALOHA tool instead of the KORA tool in rural conditions, users should be careful not to cause any differences in impact distance due to input errors of weather variables, with the most sensitive one being atmospheric stability.

  14. Formal language constrained path problems

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, C.; Jacob, R.; Marathe, M.

    1997-07-08

    In many path finding problems arising in practice, certain patterns of edge/vertex labels in the labeled graph being traversed are allowed/preferred, while others are disallowed. Motivated by such applications as intermodal transportation planning, the authors investigate the complexity of finding feasible paths in a labeled network, where the mode choice for each traveler is specified by a formal language. The main contributions of this paper include the following: (1) the authors show that the problem of finding a shortest path between a source and destination for a traveler whose mode choice is specified as a context free language is solvable efficiently in polynomial time, when the mode choice is specified as a regular language they provide algorithms with improved space and time bounds; (2) in contrast, they show that the problem of finding simple paths between a source and a given destination is NP-hard, even when restricted to very simple regular expressions and/or very simple graphs; (3) for the class of treewidth bounded graphs, they show that (i) the problem of finding a regular language constrained simple path between source and a destination is solvable in polynomial time and (ii) the extension to finding context free language constrained simple paths is NP-complete. Several extensions of these results are presented in the context of finding shortest paths with additional constraints. These results significantly extend the results in [MW95]. As a corollary of the results, they obtain a polynomial time algorithm for the BEST k-SIMILAR PATH problem studied in [SJB97]. The previous best algorithm was given by [SJB97] and takes exponential time in the worst case.

  15. [Body image dissatisfaction as a mediator of the association between BMI, self-esteem and mental health in early adolescents: a multiple-group path analysis across gender].

    Science.gov (United States)

    Jang, Mi Heui; Lee, Gyungjoo

    2013-04-01

    This study was done to examine not only the relationships between body mass index (BMI), self-esteem, body image dissatisfaction (BID) and mental health, according to gender, but the mediating role of BID on mental health in relation to BMI and self-esteem among early adolescents. Data from 576 (296 boys and 280 girls) elementary school students in grades 5 to 6 were collected. A multiple-group path analysis was utilized to examine the relationships between BMI, self-esteem, BID and mental health by gender. In the path analysis for all students, poor mental health was related directly to BID, while it was indirectly related to BMI and self-esteem. In the multiple-group path analysis of both genders, BID was found to have a significant direct and indirect effect on mental health for girls alone. The findings suggested that BID should be examined early to prevent poor mental health in early adolescent girls. This study helps to elucidate the role of early adolescent BID on mental health and provides insight for further prevention and intervention programs in school and community mental health settings.

  16. Assessment of direct analgesic effect of duloxetine for chronic low back pain: post hoc path analysis of double-blind, placebo-controlled studies

    Directory of Open Access Journals (Sweden)

    Enomoto H

    2017-06-01

    Full Text Available Hiroyuki Enomoto,1 Shinji Fujikoshi,2 Jumpei Funai,3 Nao Sasaki,4 Michael H Ossipov,5 Toshinaga Tsuji,6 Levent Alev,7 Takahiro Ushida8 1Medical Science, Eli Lilly Japan K.K., Tokyo, 2Statistical Science, 3Science Communications, 4Medical Science, Eli Lilly Japan K.K., Kobe, Japan; 5Clinical Division, inVentiv Health, LLC, Blue Bell, PA, USA; 6Medical Affairs Department, Shionogi & Co., Ltd., Osaka, Japan; 7Medical Department, Lilly Turkey, Istanbul, Turkey; 8Multidisciplinary Pain Center, Aichi Medical University, Nagakute, Aichi, Japan Background: Comorbid depression and depressive symptoms are common in patients with chronic low back pain (CLBP. Duloxetine is clinically effective in major depressive disorder and several chronic pain states, including CLBP. The objective of this post hoc meta-analysis was to assess direct and indirect analgesic efficacy of duloxetine for patients with CLBP in previous clinical trials. Methods: Post hoc path analyses were conducted of 3 randomized, double-blind, clinical studies of patients receiving duloxetine or placebo for CLBP. The primary outcome measure for pain was the Brief Pain Inventory, average pain score. A secondary outcome measure, the Beck Depression Inventory-II, was used for depressive symptoms. The changes in score from baseline to endpoint were determined for each index. Path analyses were employed to calculate the proportion of analgesia that may be attributed to a direct effect of duloxetine on pain.Results: A total of 851 patients (400 duloxetine and 451 placebo were included in this analysis. Duloxetine significantly improved pain scores compared with placebo (p<0.001. It also significantly improved depressive scores compared with placebo (p=0.015. Path analyses showed that 91.1% of the analgesic effect of duloxetine could be attributed to a direct analgesic effect, and 8.9% to its antidepressant effect. Similar results were obtained when data were evaluated at weeks 4 and 7, and when

  17. Variability Bugs in Highly Configurable Systems: A Qualitative Analysis

    DEFF Research Database (Denmark)

    Abal, Iago; Melo, Jean; Stanciulescu, Stefan

    2018-01-01

    Variability-sensitive verification pursues effective analysis of the exponentially many variants in number of features of a program family. Several variability-aware techniques have been proposed, but researchers still lack examples of concrete bugs induced by variability, occurring in real large......-scale systems. A collection of real world bugs is needed to evaluate tool implementations of variability-sensitive analyses by testing them on real bugs. We present a qualitative study of 98 diverse variability bugs collected from bug-fixing commits in the Apache, BusyBox, Linux kernel and Marlin repositories....... We analyze each of the bugs, and record the results in a database. For each bug, we create a self-contained simplified C99 version and a simplified patch, in order to help researchers who are not experts on these subject studies to understand them, so that they can use it for evaluation...

  18. Configurbanist : Urban Configuration Analysis for Walking and Cycling via Easiest Paths

    NARCIS (Netherlands)

    Nourian Ghadikolaee, P.; Rezvani, S.; Sariyildiz, I.S.; Van der Hoeven, F.D.

    In a quest for promoting sustainable modes of mobility, we have revisited how feasible and suitable is it for people to walk or cycle to their destinations in a neighbourhood. We propose a few accessibility measures based on an 'Easiest Path' algorithm that provides also actual temporal distance

  19. [Association between Emotional Labor, Emotional Dissonance, Burnout and Turnover Intention in Clinical Nurses: A Multiple-Group Path Analysis across Job Satisfaction].

    Science.gov (United States)

    Back, Chi Yun; Hyun, Dae Sung; Chang, Sei Jin

    2017-12-01

    This study was conducted to investigate the influence of emotional labor, emotional dissonance, and burnout on nurse's turnover intention and examine the effect of job satisfaction on the relationships among emotional labor, emotional dissonance, burnout, and turnover intention. The sample consisted of 350 nurses recruited from 6 general hospitals in 2 cities in Korea. A multiple-group analysis was utilized. Data were analyzed using SPSS statistics 23 and AMOS 20. In the path analysis, turnover intention was directly related to burnout in clinical nurses who had a high job satisfaction (β=.24, p=.003), while it was indirectly related to emotional dissonance (β=.13, p=.002). In the multiple-group path analysis, turnover intention was directly related to emotional dissonance (β=.18, p=.033) and burnout (β=.26, p=.002) for nurses with low job satisfaction. These results indicate that manuals and guidelines to alleviate the negative effects of emotional labor, emotional dissonance, and burnout, and to increase job satisfaction are strongly required to reduce turnover intention in nurses at the organizational level as well as at the individual level. © 2017 Korean Society of Nursing Science

  20. On the structure of path-like trees

    OpenAIRE

    Muntaner Batle, Francesc Antoni; Rius Font, Miquel

    2007-01-01

    We study the structure of path-like trees. In order to do this, we introduce a set of trees that we call expandable trees. In this paper we also generalize the concept of path-like trees and we call such generalization generalized path-like trees. As in the case of path-like trees, generalized path-like trees, have very nice labeling properties.

  1. Class start times, sleep, and academic performance in college: a path analysis.

    Science.gov (United States)

    Onyper, Serge V; Thacher, Pamela V; Gilbert, Jack W; Gradess, Samuel G

    2012-04-01

    Path analysis was used to examine the relationship between class start times, sleep, circadian preference, and academic performance in college-aged adults. Consistent with observations in middle and high school students, college students with later class start times slept longer, experienced less daytime sleepiness, and were less likely to miss class. Chronotype was an important moderator of sleep schedules and daytime functioning; those with morning preference went to bed and woke up earlier and functioned better throughout the day. The benefits of taking later classes did not extend to academic performance, however; grades were somewhat lower in students with predominantly late class schedules. Furthermore, students taking later classes were at greater risk for increased alcohol consumption, and among all the factors affecting academic performance, alcohol misuse exerted the strongest effect. Thus, these results indicate that later class start times in college, while allowing for more sleep, also increase the likelihood of alcohol misuse, ultimately impeding academic success.

  2. Correlation and path coefficient analysis of quantitative characters in spine gourd (Momordica dioica Roxb.).

    Science.gov (United States)

    Aliya, F; Begum, H; Reddy, M T; Sivaraj, N; Pandravada, S R; Narshimulu, G

    2014-05-01

    Fifty genotypes of spine gourd (Momordica dioica Roxb.) were evaluated in a randomized block design with two replications at the Vegetable Research Station, Rajendranagar, Hyderabad, Andhra Pradesh, India during kharif, 2012. Correlation and path coefficient analysis were carried out to study the character association and contribution, respectively for twelve quantitative characters namely vine length (m), number of stems per plant, days to first female flower appearance, first female flowering node, days to first fruit harvest, days to last fruit harvest, fruiting period (days), fruit length (cm), fruit width (cm), fruit weight (g), number of fruits per plant and fruit yield per plant (kg) for identification of the potential selection indices. Correlation and path coefficient analyses revealed that fruiting period and number of fruits per plant not only had positively significant correlation with fruit yield but also had positively high direct effect on it and are regarded as the main determinants of fruit yield. Days to first fruit harvest had positively moderate direct effect on fruit yield and its association was negatively significant, days to last fruit harvest had negatively high direct effect on fruit yield and its association was significant positively, hence restricted simultaneous selection can be made for days to first fruit harvest and days to last fruit harvest. The improvement in fruit yield can be effective if selection is based on days to first fruit harvest, days to last fruit harvest, fruiting period and number of fruits per plant.

  3. The Analysis of Factors Influencing Effectivenes of Property Taxes in Karanganyar Regency

    Directory of Open Access Journals (Sweden)

    Endang Brotojoyo

    2018-03-01

    Full Text Available The purpose of this study was to test empirically Effect of Compensation, Motivation and External Factors To Performance Officer With Property Taxes Voting in the District Effectiveness Matesih Karanganyar. The analysis technique used is using validity and reliability test, linearity test, regression analysis, path analysis, t test, F test, test the coefficient of determination and correlation analysis. Compensation Hypothesis Test Results significantly influence the effectiveness of tax collection. Motivation significantly influences the effectiveness of tax collection. External factors do not significant effect on effectiveness of tax collection. Compensation significant effect on the performance of Officers. Motivation significant effect on the performance of the Property Taxes polling clerk. External factors do not significant effect on the performance of Officers. Effectiveness of tax collection clerk significant effects on performance. F test results can be concluded jointly variable compensation, motivation, and external factors affecting the effectiveness of tax collection performance. The R2 total of 0,974 means that the performance of the Property Taxes in the district polling officer Matesih Karanganyar explained by the variable compensation, motivation, external factors and the effectiveness of tax collection amounted to 97.4%. The results of path analysis showed that the effective compensation and motivation through a direct path, while external factors are not effective for direct and indirect pathways.

  4. Estimation of indirect effect when the mediator is a censored variable.

    Science.gov (United States)

    Wang, Jian; Shete, Sanjay

    2017-01-01

    A mediation model explores the direct and indirect effects of an initial variable ( X) on an outcome variable ( Y) by including a mediator ( M). In many realistic scenarios, investigators observe censored data instead of the complete data. Current research in mediation analysis for censored data focuses mainly on censored outcomes, but not censored mediators. In this study, we proposed a strategy based on the accelerated failure time model and a multiple imputation approach. We adapted a measure of the indirect effect for the mediation model with a censored mediator, which can assess the indirect effect at both the group and individual levels. Based on simulation, we established the bias in the estimations of different paths (i.e. the effects of X on M [ a], of M on Y [ b] and of X on Y given mediator M [ c']) and indirect effects when analyzing the data using the existing approaches, including a naïve approach implemented in software such as Mplus, complete-case analysis, and the Tobit mediation model. We conducted simulation studies to investigate the performance of the proposed strategy compared to that of the existing approaches. The proposed strategy accurately estimates the coefficients of different paths, indirect effects and percentages of the total effects mediated. We applied these mediation approaches to the study of SNPs, age at menopause and fasting glucose levels. Our results indicate that there is no indirect effect of association between SNPs and fasting glucose level that is mediated through the age at menopause.

  5. Controlling the optical path length in turbid media using differential path-length spectroscopy: fiber diameter dependence

    NARCIS (Netherlands)

    Kaspers, O. P.; Sterenborg, H. J. C. M.; Amelink, A.

    2008-01-01

    We have characterized the path length for the differential path-length spectroscopy (DPS) fiber optic geometry for a wide range of optical properties and for fiber diameters ranging from 200 mu m to 1000 mu m. Phantom measurements show that the path length is nearly constant for scattering

  6. Consistency Analysis of Ultrasound Echoes within a Dual Symmetric Path Inspection Framework

    Directory of Open Access Journals (Sweden)

    VASILE, C.

    2015-05-01

    Full Text Available Non-destructive ultrasound inspection of metallic structures is a perpetual high-interest area of research because of its well-known benefits in industrial applications, especially from an economic point of view, where detection and localisation of defects in their most initial stages can help maintain high production capabilities for any enterprise. This paper is aimed at providing further validation regarding a new technique for detecting and localising defects in metals, the Matched Filter-based Dual Symmetric Path Inspection (MF-DSPI. This validation consists in demonstrating the consistency of the useful ultrasound echoes, within the framework of the MF-DSPI. A description of the MF-DSPI method and the related work of the authors with it are presented in this paper, along with an experimental setup used to obtain the data with which the useful echo consistency was studied. The four proposed methods are: signal envelope analysis, L2-norm criterion, correlation coefficient criterion and sliding bounding rectangle analysis. The aim of this paper is to verify the useful echo consistency (with the help of these four approaches, as the MF-DSPI method strongly relies on this feature. The results and their implications are discussed in the latter portion of this study.

  7. Multigroup Path Analysis of the Influence of Healthcare Quality, by Different Health Insurance Types.

    Science.gov (United States)

    Hong, Yong-Rock; Holcomb, Derek; Ballard, Michael; Schwartz, Laurel

    Winds of change have been blowing in the U.S. healthcare system since passage of the Affordable Care Act. Examining differences between individuals covered by different types of insurance is essential if healthcare executives are to develop new strategies in response to the emerging health insurance market. In this study, we used multigroup path analysis models to examine the moderating effects of health insurance on direct and indirect associations with general health status, satisfaction with received care, financial burden, and perceived value of the healthcare system. Data were obtained from the 2012 Medical Expenditure Panel Survey and analyzed according to the types of insurance: private, public, and military. With the satisfactory fit of the model (χ = 2,532.644, df = 96, p spending.

  8. Stigmatization and self-determination of preregistration nurses: A path analysis.

    Science.gov (United States)

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

    2018-02-01

    The concept of stigma and the stigmatizing behaviours of health-care professionals can have a profound influence on people with mental illness. A key construct that has been identified as influencing our behaviours is self-determination. As such, in the present study, we attempted to examine the connection and influence of motivational measures on the stigmatization of preregistration nurses. Data were collected once using three surveys that measured the motivational responses and stigmatizing behaviours of preregistration nurses after an approved mental health clinical placement. Using a path analysis, the results indicated that psychological needs significantly influenced preregistration nurses' self-determination towards work. In addition, self-determination was a significant influence on the stigmatization behaviours of preregistration nurses. The results of the present study provide initial empirical evidence that supports the importance of professional self-determination and the potential connection of quality care, as illustrated with the low stigmatizing behaviours of preregistration nurses who are more self-determined towards their work/career. Because of the significant results of the present study, it is recommended that future research is needed that uses self-determination theory as a lens to understand the application and importance within the field of nurse education. © 2017 Australian College of Mental Health Nurses Inc.

  9. ARTICLE - Path analysis of iron and zinc contents and others traits in cowpea

    Directory of Open Access Journals (Sweden)

    Jeane de Oliveira Moura

    2012-12-01

    Full Text Available The objective of this study was to estimate the direct and indirect effects of agronomic and culinary traits on iron and zinc contents in 11 cowpea populations. Correlations between traits were estimated and decomposed into direct and indirect effects using path analysis. For the study populations, breeding for larger grain size, higher number of grains per pod, grain yield, reduced cooking time, and number of days to flowering can lead to decreases in the levels of iron and zinc in the grain. Genetic gains for the iron content can be obtained by direct selection for protein content by indirect effects on the number of grains per pod, 100-grain weight and grain yield. The positive direct effect of grain size and protein content on the zinc content indicates the possibility of simultaneous gain by combined selection of these traits.

  10. Computed micro-tomographic evaluation of glide path with nickel-titanium rotary PathFile in maxillary first molars curved canals.

    Science.gov (United States)

    Pasqualini, Damiano; Bianchi, Caterina Chiara; Paolino, Davide Salvatore; Mancini, Lucia; Cemenasco, Andrea; Cantatore, Giuseppe; Castellucci, Arnaldo; Berutti, Elio

    2012-03-01

    X-ray computed micro-tomography scanning allows high-resolution 3-dimensional imaging of small objects. In this study, micro-CT scanning was used to compare the ability of manual and mechanical glide path to maintain the original root canal anatomy. Eight extracted upper first permanent molars were scanned at the TOMOLAB station at ELETTRA Synchrotron Light Laboratory in Trieste, Italy, with a microfocus cone-beam geometry system. A total of 2,400 projections on 360° have been acquired at 100 kV and 80 μA, with a focal spot size of 8 μm. Buccal root canals of each specimen (n = 16) were randomly assigned to PathFile (P) or stainless-steel K-file (K) to perform glide path at the full working length. Specimens were then microscanned at the apical level (A) and at the point of the maximum curvature level (C) for post-treatment analyses. Curvatures of root canals were classified as moderate (≤35°) or severe (≥40°). The ratio of diameter ratios (RDRs) and the ratio of cross-sectional areas (RAs) were assessed. For each level of analysis (A and C), 2 balanced 2-way factorial analyses of variance (P < .05) were performed to evaluate the significance of the instrument factor and of canal curvature factor as well as the interactions of the factors both with RDRs and RAs. Specimens in the K group had a mean curvature of 35.4° ± 11.5°; those in the P group had a curvature of 38° ± 9.9°. The instrument factor (P and K) was extremely significant (P < .001) for both the RDR and RA parameters, regardless of the point of analysis. Micro-CT scanning confirmed that NiTi rotary PathFile instruments preserve the original canal anatomy and cause less canal aberrations. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  11. ANÁLISE DE TRILHA DO RENDIMENTO DO FEIJOEIRO E SEUS COMPONENTES PRIMÁRIOS EM MONOCULTIVO E EM CONSÓRCIO COM A CULTURA DO MILHO PATH ANALYSIS OF GRAIN YIELD OF COMMON BEAN AND ITS PRIMARY COMPONENTS IN MONOCULTURE AND INTERCROPPED WITH MAIZE

    Directory of Open Access Journals (Sweden)

    Marcos Ribeiro Furtado

    2002-04-01

    Full Text Available Realizou-se análise de trilha do rendimento de grãos (variável básica vs. seus componentes primários (variáveis explicativas, em monocultivo e em consórcio com a cultura do milho. De modo geral, os resultados foram semelhantes nos dois sistemas de cultivo. Das três variáveis explicativas envolvidas no estudo, o número de vagens por parcela foi a única que apresentou boa combinação de coeficiente de trilha e correlação, ambos altos, tanto no monocultivo como no consórcio. Concluiu-se que o caráter número de vagens por parcela tem influência marcante na produção de grãos, podendo ser de grande valor nos progressos genéticos deste caráter, via seleção indireta.Path analysis of grain yield (basic variable and its primary components (explicatory variables was worked in common bean in monoculture and intercropped with maize. In general, the results were similar in both cropping systems. Among the explicatory variables studied, only the number of pods per plot showed a good combination of path coefficient and correlation, both high, in monoculture and intercropped. It could be concluded that the character number of pods per plot has an important influence on grain yield, which may be of great value for genetic gains in this character, by indirect selection.

  12. Atlantic leatherback migratory paths and temporary residence areas.

    Directory of Open Access Journals (Sweden)

    Sabrina Fossette

    Full Text Available BACKGROUND: Sea turtles are long-distance migrants with considerable behavioural plasticity in terms of migratory patterns, habitat use and foraging sites within and among populations. However, for the most widely migrating turtle, the leatherback turtle Dermochelys coriacea, studies combining data from individuals of different populations are uncommon. Such studies are however critical to better understand intra- and inter-population variability and take it into account in the implementation of conservation strategies of this critically endangered species. Here, we investigated the movements and diving behaviour of 16 Atlantic leatherback turtles from three different nesting sites and one foraging site during their post-breeding migration to assess the potential determinants of intra- and inter-population variability in migratory patterns. METHODOLOGY/PRINCIPAL FINDINGS: Using satellite-derived behavioural and oceanographic data, we show that turtles used Temporary Residence Areas (TRAs distributed all around the Atlantic Ocean: 9 in the neritic domain and 13 in the oceanic domain. These TRAs did not share a common oceanographic determinant but on the contrary were associated with mesoscale surface oceanographic features of different types (i.e., altimetric features and/or surface chlorophyll a concentration. Conversely, turtles exhibited relatively similar horizontal and vertical behaviours when in TRAs (i.e., slow swimming velocity/sinuous path/shallow dives suggesting foraging activity in these productive regions. Migratory paths and TRAs distribution showed interesting similarities with the trajectories of passive satellite-tracked drifters, suggesting that the general dispersion pattern of adults from the nesting sites may reflect the extent of passive dispersion initially experienced by hatchlings. CONCLUSIONS/SIGNIFICANCE: Intra- and inter-population behavioural variability may therefore be linked with initial hatchling drift scenarios

  13. The Health Action Process Approach as a Motivational Model of Dietary Self-Management for People with Multiple Sclerosis: A Path Analysis

    Science.gov (United States)

    Chiu, Chung-Yi; Lynch, Ruth Torkelson; Chan, Fong; Rose, Lindsey

    2012-01-01

    The main objective of this study was to evaluate the health action process approach (HAPA) as a motivational model for dietary self-management for people with multiple sclerosis (MS). Quantitative descriptive research design using path analysis was used. Participants were 209 individuals with MS recruited from the National MS Society and a…

  14. Storm-tracks interannual variability and large-scale climate modes

    Science.gov (United States)

    Liberato, Margarida L. R.; Trigo, Isabel F.; Trigo, Ricardo M.

    2013-04-01

    In this study we focus on the interannual variability and observed changes in northern hemisphere mid-latitude storm-tracks and relate them to large scale atmospheric circulation variability modes. Extratropical storminess, cyclones dominant paths, frequency and intensity have long been the object of climatological studies. The analysis of storm characteristics and historical trends presented here is based on the cyclone detecting and tracking algorithm first developed for the Mediterranean region (Trigo et al. 1999) and recently extended to a larger Euro-Atlantic region (Trigo 2006). The objective methodology, which identifies and follows individual lows as minima in SLP fields, fulfilling a set of conditions regarding the central pressure and the pressure gradient, is applied to the northern hemisphere 6-hourly geopotential data at 1000 hPa from the 20th Century Reanalyses (20CRv2) project and from reanalyses datasets provided by the European Centre for Medium-Range Weather Forecasts (ECMWF): ERA-40 and ERA Interim reanalyses. First, we assess the interannual variability and cyclone frequency trends for each of the datasets, for the 20th century and for the period between 1958 and 2002 using the highest spatial resolution available (1.125° x 1.125°) from the ERA-40 data. Results show that winter variability of storm paths, cyclone frequency and travel times is in agreement with the reported variability in a number of large-scale climate patterns (including the North Atlantic Oscillation, the East Atlantic Pattern and the Scandinavian Pattern). In addition, three storm-track databases are built spanning the common available extended winter seasons from October 1979 to March 2002. Although relatively short, this common period allows a comparison of systems represented in reanalyses datasets with distinct horizontal resolutions. This exercise is mostly focused on the key areas of cyclogenesis and cyclolysis and main cyclone characteristics over the northern

  15. Master equations and the theory of stochastic path integrals

    Science.gov (United States)

    Weber, Markus F.; Frey, Erwin

    2017-04-01

    This review provides a pedagogic and self-contained introduction to master equations and to their representation by path integrals. Since the 1930s, master equations have served as a fundamental tool to understand the role of fluctuations in complex biological, chemical, and physical systems. Despite their simple appearance, analyses of master equations most often rely on low-noise approximations such as the Kramers-Moyal or the system size expansion, or require ad-hoc closure schemes for the derivation of low-order moment equations. We focus on numerical and analytical methods going beyond the low-noise limit and provide a unified framework for the study of master equations. After deriving the forward and backward master equations from the Chapman-Kolmogorov equation, we show how the two master equations can be cast into either of four linear partial differential equations (PDEs). Three of these PDEs are discussed in detail. The first PDE governs the time evolution of a generalized probability generating function whose basis depends on the stochastic process under consideration. Spectral methods, WKB approximations, and a variational approach have been proposed for the analysis of the PDE. The second PDE is novel and is obeyed by a distribution that is marginalized over an initial state. It proves useful for the computation of mean extinction times. The third PDE describes the time evolution of a ‘generating functional’, which generalizes the so-called Poisson representation. Subsequently, the solutions of the PDEs are expressed in terms of two path integrals: a ‘forward’ and a ‘backward’ path integral. Combined with inverse transformations, one obtains two distinct path integral representations of the conditional probability distribution solving the master equations. We exemplify both path integrals in analysing elementary chemical reactions. Moreover, we show how a well-known path integral representation of averaged observables can be recovered from

  16. Master equations and the theory of stochastic path integrals.

    Science.gov (United States)

    Weber, Markus F; Frey, Erwin

    2017-04-01

    This review provides a pedagogic and self-contained introduction to master equations and to their representation by path integrals. Since the 1930s, master equations have served as a fundamental tool to understand the role of fluctuations in complex biological, chemical, and physical systems. Despite their simple appearance, analyses of master equations most often rely on low-noise approximations such as the Kramers-Moyal or the system size expansion, or require ad-hoc closure schemes for the derivation of low-order moment equations. We focus on numerical and analytical methods going beyond the low-noise limit and provide a unified framework for the study of master equations. After deriving the forward and backward master equations from the Chapman-Kolmogorov equation, we show how the two master equations can be cast into either of four linear partial differential equations (PDEs). Three of these PDEs are discussed in detail. The first PDE governs the time evolution of a generalized probability generating function whose basis depends on the stochastic process under consideration. Spectral methods, WKB approximations, and a variational approach have been proposed for the analysis of the PDE. The second PDE is novel and is obeyed by a distribution that is marginalized over an initial state. It proves useful for the computation of mean extinction times. The third PDE describes the time evolution of a 'generating functional', which generalizes the so-called Poisson representation. Subsequently, the solutions of the PDEs are expressed in terms of two path integrals: a 'forward' and a 'backward' path integral. Combined with inverse transformations, one obtains two distinct path integral representations of the conditional probability distribution solving the master equations. We exemplify both path integrals in analysing elementary chemical reactions. Moreover, we show how a well-known path integral representation of averaged observables can be recovered from them. Upon

  17. Localization Decisions of Entrepreneurs: The Role of Path Dependency and Market Forces

    Science.gov (United States)

    Pylak, Korneliusz; Majerek, Dariusz

    2017-10-01

    The purpose of this research is to determine the role of path dependency and market forces in the localization decisions of entrepreneurs from different industries. We hypothesize that most industries develop new entities based on the number of companies from the same industry that already exist in a region. We also hypothesize that entrepreneurs create new entities based on related industries operating within the same knowledge pool. To test these hypotheses, we used the machine learning decision tree method. The input variables are the number of companies from 86 industries located in 2,531 communities in Poland in 2009. The target values are the number of new companies from these industries created in the years 2009-2015. The principal results show that localization decisions are mostly based on demand and supply industries, in which manufacturing industries play crucial role. Path dependency appears in less than half of the industries’ models and thus is not the main factor influencing decisions regarding the creation of new companies. The highest share of path-dependent industries is in manufacturing sector, but the degree of the dependence is lower than in the service sector. The service sector seems to be the least path-dependent, as services usually serve other industries. Competition in industries is a rare factor in new company creation; however, if it appears, it usually shrinks the industry.

  18. Walking path-planning method for multiple radiation areas

    International Nuclear Information System (INIS)

    Liu, Yong-kuo; Li, Meng-kun; Peng, Min-jun; Xie, Chun-li; Yuan, Cheng-qian; Wang, Shuang-yu; Chao, Nan

    2016-01-01

    Highlights: • Radiation environment modeling method is designed. • Path-evaluating method and segmented path-planning method are proposed. • Path-planning simulation platform for radiation environment is built. • The method avoids to be misled by minimum dose path in single area. - Abstract: Based on minimum dose path-searching method, walking path-planning method for multiple radiation areas was designed to solve minimum dose path problem in single area and find minimum dose path in the whole space in this paper. Path-planning simulation platform was built using C# programming language and DirectX engine. The simulation platform was used in simulations dealing with virtual nuclear facilities. Simulation results indicated that the walking-path planning method is effective in providing safety for people walking in nuclear facilities.

  19. Kinetic constrained optimization of the golf swing hub path.

    Science.gov (United States)

    Nesbit, Steven M; McGinnis, Ryan S

    2014-12-01

    This study details an optimization of the golf swing, where the hand path and club angular trajectories are manipulated. The optimization goal was to maximize club head velocity at impact within the interaction kinetic limitations (force, torque, work, and power) of the golfer as determined through the analysis of a typical swing using a two-dimensional dynamic model. The study was applied to four subjects with diverse swing capabilities and styles. It was determined that it is possible for all subjects to increase their club head velocity at impact within their respective kinetic limitations through combined modifications to their respective hand path and club angular trajectories. The manner of the modifications, the degree of velocity improvement, the amount of kinetic reduction, and the associated kinetic limitation quantities were subject dependent. By artificially minimizing selected kinetic inputs within the optimization algorithm, it was possible to identify swing trajectory characteristics that indicated relative kinetic weaknesses of a subject. Practical implications are offered based upon the findings of the study. Key PointsThe hand path trajectory is an important characteristic of the golf swing and greatly affects club head velocity and golfer/club energy transfer.It is possible to increase the energy transfer from the golfer to the club by modifying the hand path and swing trajectories without increasing the kinetic output demands on the golfer.It is possible to identify relative kinetic output strengths and weakness of a golfer through assessment of the hand path and swing trajectories.Increasing any one of the kinetic outputs of the golfer can potentially increase the club head velocity at impact.The hand path trajectory has important influences over the club swing trajectory.

  20. Optimal Paths in Gliding Flight

    Science.gov (United States)

    Wolek, Artur

    Underwater gliders are robust and long endurance ocean sampling platforms that are increasingly being deployed in coastal regions. This new environment is characterized by shallow waters and significant currents that can challenge the mobility of these efficient (but traditionally slow moving) vehicles. This dissertation aims to improve the performance of shallow water underwater gliders through path planning. The path planning problem is formulated for a dynamic particle (or "kinematic car") model. The objective is to identify the path which satisfies specified boundary conditions and minimizes a particular cost. Several cost functions are considered. The problem is addressed using optimal control theory. The length scales of interest for path planning are within a few turn radii. First, an approach is developed for planning minimum-time paths, for a fixed speed glider, that are sub-optimal but are guaranteed to be feasible in the presence of unknown time-varying currents. Next the minimum-time problem for a glider with speed controls, that may vary between the stall speed and the maximum speed, is solved. Last, optimal paths that minimize change in depth (equivalently, maximize range) are investigated. Recognizing that path planning alone cannot overcome all of the challenges associated with significant currents and shallow waters, the design of a novel underwater glider with improved capabilities is explored. A glider with a pneumatic buoyancy engine (allowing large, rapid buoyancy changes) and a cylindrical moving mass mechanism (generating large pitch and roll moments) is designed, manufactured, and tested to demonstrate potential improvements in speed and maneuverability.

  1. Path following control of planar snake robots using virtual holonomic constraints: theory and experiments.

    Science.gov (United States)

    Rezapour, Ehsan; Pettersen, Kristin Y; Liljebäck, Pål; Gravdahl, Jan T; Kelasidi, Eleni

    This paper considers path following control of planar snake robots using virtual holonomic constraints. In order to present a model-based path following control design for the snake robot, we first derive the Euler-Lagrange equations of motion of the system. Subsequently, we define geometric relations among the generalized coordinates of the system, using the method of virtual holonomic constraints. These appropriately defined constraints shape the geometry of a constraint manifold for the system, which is a submanifold of the configuration space of the robot. Furthermore, we show that the constraint manifold can be made invariant by a suitable choice of feedback. In particular, we analytically design a smooth feedback control law to exponentially stabilize the constraint manifold. We show that enforcing the appropriately defined virtual holonomic constraints for the configuration variables implies that the robot converges to and follows a desired geometric path. Numerical simulations and experimental results are presented to validate the theoretical approach.

  2. Cooperative path planning of unmanned aerial vehicles

    CERN Document Server

    Tsourdos, Antonios; Shanmugavel, Madhavan

    2010-01-01

    An invaluable addition to the literature on UAV guidance and cooperative control, Cooperative Path Planning of Unmanned Aerial Vehicles is a dedicated, practical guide to computational path planning for UAVs. One of the key issues facing future development of UAVs is path planning: it is vital that swarm UAVs/ MAVs can cooperate together in a coordinated manner, obeying a pre-planned course but able to react to their environment by communicating and cooperating. An optimized path is necessary in order to ensure a UAV completes its mission efficiently, safely, and successfully. Focussing on the path planning of multiple UAVs for simultaneous arrival on target, Cooperative Path Planning of Unmanned Aerial Vehicles also offers coverage of path planners that are applicable to land, sea, or space-borne vehicles. Cooperative Path Planning of Unmanned Aerial Vehicles is authored by leading researchers from Cranfield University and provides an authoritative resource for researchers, academics and engineers working in...

  3. Using meta-analytic path analysis to test theoretical predictions in health behavior: An illustration based on meta-analyses of the theory of planned behavior.

    Science.gov (United States)

    Hagger, Martin S; Chan, Derwin K C; Protogerou, Cleo; Chatzisarantis, Nikos L D

    2016-08-01

    Synthesizing research on social cognitive theories applied to health behavior is an important step in the development of an evidence base of psychological factors as targets for effective behavioral interventions. However, few meta-analyses of research on social cognitive theories in health contexts have conducted simultaneous tests of theoretically-stipulated pattern effects using path analysis. We argue that conducting path analyses of meta-analytic effects among constructs from social cognitive theories is important to test nomological validity, account for mediation effects, and evaluate unique effects of theory constructs independent of past behavior. We illustrate our points by conducting new analyses of two meta-analyses of a popular theory applied to health behaviors, the theory of planned behavior. We conducted meta-analytic path analyses of the theory in two behavioral contexts (alcohol and dietary behaviors) using data from the primary studies included in the original meta-analyses augmented to include intercorrelations among constructs and relations with past behavior missing from the original analysis. Findings supported the nomological validity of the theory and its hypotheses for both behaviors, confirmed important model processes through mediation analysis, demonstrated the attenuating effect of past behavior on theory relations, and provided estimates of the unique effects of theory constructs independent of past behavior. Our analysis illustrates the importance of conducting a simultaneous test of theory-stipulated effects in meta-analyses of social cognitive theories applied to health behavior. We recommend researchers adopt this analytic procedure when synthesizing evidence across primary tests of social cognitive theories in health. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. When the 'soft-path' gets hard: demand management and financial instability for water utilities

    Science.gov (United States)

    Zeff, H. B.; Characklis, G. W.

    2014-12-01

    In the past, cost benefit analysis (CBA) has been viewed as an effective means of evaluating water utility strategies, particularly those that were dependent on the construction of new supply infrastructure. As water utilities have begun to embrace 'soft-path' approaches as a way to reduce the need for supply-centric development, CBA fails to recognize some important financial incentives affected by reduced water consumption. Demand management, both as a short-term response to drought and in longer-term actions to accommodate demand growth, can introduce revenue risks that adversely affect a utility's ability to repay debt, re-invest in aging infrastructure, or maintain reserve funds for use in a short-term emergency. A utility that does not generate sufficient revenue to support these functions may be subject to credit rating downgrades, which in turn affect the interest rate it pays on its debt. Interest rates are a critical consideration for utility managers in the capital-intensive water sector, where debt payments for infrastructure often account for a large portion of a utility's overall costs. Even a small increase in interest rates can add millions of dollars to the cost of new infrastructure. Recent studies have demonstrated that demand management techniques can lead to significant revenue variability, and credit rating agencies have begun to take notice of drought response plans when evaluating water utility credit ratings, providing utilities with a disincentive to fully embrace soft-path approaches. This analysis examines the impact of demand management schemes on key credit rating metrics for a water utility in Raleigh, North Carolina. The utility's consumer base is currently experiencing rapid population growth, and demand management has the potential to reduce the dependence on costly new supply infrastructure but could lead to financial instability that will significantly increase the costs of financing future projects. This work analyzes how 'soft-path

  5. THE INFLUENCE OF EMPLOYEE JOB SATISFACTION AND SERVICE QUALITY ON PROFITABILITY IN PT. BANK JATIM: CUSTOMER SATISFACTION AS THE INTERVENING VARIABLE

    Directory of Open Access Journals (Sweden)

    Finanda Y.D.

    2018-02-01

    Full Text Available This research aimed to examine the influence of employee job satisfaction and service quality on profitability in PT. Bank Jatim, in which customer satisfaction was the intervening variable. According to literature review, the hypothesis of the research stated that employee job satisfaction and service quality influenced the profitability of the Bank and customer satisfaction as intervening variable proved to affect the relationship between independent variable and dependent variable. The data of the research were collected by using questionnaire from respondents that consisted of 92 permanent employees of PT. Bank Jatim in Gresik City. The technique of hypothesis testing was performed by using Multiple Regression Analysis (MRA and Path Analysis using SPSS 24 statistical application. The findings of the research indicated that employee job satisfaction and service quality have positive effect to profitability and customer satisfaction was shown as intervening variable. Specifically, this research found that employee satisfaction and service quality will improve the profitability of the company.

  6. Energy consumption of ProTaper Next X1 after glide path with PathFiles and ProGlider.

    Science.gov (United States)

    Berutti, Elio; Alovisi, Mario; Pastorelli, Michele Angelo; Chiandussi, Giorgio; Scotti, Nicola; Pasqualini, Damiano

    2014-12-01

    Instrument failure caused by excessive torsional stress can be controlled by creating a manual or mechanical glide path. The ProGlider single-file system (Dentsply Maillefer, Ballaigues, Switzerland) was recently introduced to perform a mechanical glide path. This study was designed to compare the effect of a glide path performed with PathFiles (Dentsply Maillefer) and ProGlider on torque, time, and pecking motion required for ProTaper Next X1 (Dentsply Maillefer) to reach the full working length in simulated root canals. Forty Endo Training Blocks (Dentsply Maillefer) were used. Twenty were prepared with a mechanical glide path using PathFiles 1 and 2 (the PathFile group), and 20 were prepared with a mechanical glide path using a ProGlider single file (the ProGlider group). All samples were shaped with ProTaper Next X1 driven by an endodontic motor connected to a digital wattmeter. The required torque for root canal instrumentation was analyzed by evaluating the electrical power consumption of the endodontic engine. Electric power consumption (mW/h), elapsed time (seconds), and number of pecking motions required to reach the full working length with ProTaper Next X1 were calculated. Differences among groups were analyzed with the parametric Student t test for independent data (P < .05). Elapsed time and electric power consumption were significantly different between groups (P = .0001 for both). ProGlider appears to perform more efficiently than PathFiles in decreasing electric power consumption of ProTaper Next X1 to reach the full working length. This study confirmed the ability of ProGlider to reduce stress in ProTaper Next X1 during shaping through a glide path and preliminary middle and coronal preflaring. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  7. Strain path dependency in metal plasticity

    NARCIS (Netherlands)

    Viatkina, E.M.; Brekelmans, W.A.M.; Geers, M.G.D.

    2003-01-01

    A change in strain path has a significant effect on the mechanical response of metals. Strain path change effects physically originate from a complex microstructure evolution. This paper deals with the contribution of cell structure evolution to the strain path change effect. The material with cells

  8. Path-Goal Theory of Leadership

    Science.gov (United States)

    1975-04-01

    Leadership and Turnover Among Managers ," Organization Behavior and Human Performance, 10(1973), pp. 184-200; R. J. House, "A Path-Goal Theory of...of Leadership ." 6R. J. House and G. Dessler, "Path-Goal Theory of Leadership " R. M. Stqg- dill. Managers , Employees, Organization (Ohio State...of Control." 23 R. J. House, "Notes on the Path-Goal Theory of Leadership " (University of Toronto, Faculty of Management Studies, May 1974). 24 R

  9. Path integral in Snyder space

    Energy Technology Data Exchange (ETDEWEB)

    Mignemi, S., E-mail: smignemi@unica.it [Dipartimento di Matematica e Informatica, Università di Cagliari, Viale Merello 92, 09123 Cagliari (Italy); INFN, Sezione di Cagliari, Cittadella Universitaria, 09042 Monserrato (Italy); Štrajn, R. [Dipartimento di Matematica e Informatica, Università di Cagliari, Viale Merello 92, 09123 Cagliari (Italy); INFN, Sezione di Cagliari, Cittadella Universitaria, 09042 Monserrato (Italy)

    2016-04-29

    The definition of path integrals in one- and two-dimensional Snyder space is discussed in detail both in the traditional setting and in the first-order formalism of Faddeev and Jackiw. - Highlights: • The definition of the path integral in Snyder space is discussed using phase space methods. • The same result is obtained in the first-order formalism of Faddeev and Jackiw. • The path integral formulation of the two-dimensional Snyder harmonic oscillator is outlined.

  10. Path integral in Snyder space

    International Nuclear Information System (INIS)

    Mignemi, S.; Štrajn, R.

    2016-01-01

    The definition of path integrals in one- and two-dimensional Snyder space is discussed in detail both in the traditional setting and in the first-order formalism of Faddeev and Jackiw. - Highlights: • The definition of the path integral in Snyder space is discussed using phase space methods. • The same result is obtained in the first-order formalism of Faddeev and Jackiw. • The path integral formulation of the two-dimensional Snyder harmonic oscillator is outlined.

  11. Cooperative Path-Planning for Multi-Vehicle Systems

    Directory of Open Access Journals (Sweden)

    Qichen Wang

    2014-11-01

    Full Text Available In this paper, we propose a collision avoidance algorithm for multi-vehicle systems, which is a common problem in many areas, including navigation and robotics. In dynamic environments, vehicles may become involved in potential collisions with each other, particularly when the vehicle density is high and the direction of travel is unrestricted. Cooperatively planning vehicle movement can effectively reduce and fairly distribute the detour inconvenience before subsequently returning vehicles to their intended paths. We present a novel method of cooperative path planning for multi-vehicle systems based on reinforcement learning to address this problem as a decision process. A dynamic system is described as a multi-dimensional space formed by vectors as states to represent all participating vehicles’ position and orientation, whilst considering the kinematic constraints of the vehicles. Actions are defined for the system to transit from one state to another. In order to select appropriate actions whilst satisfying the constraints of path smoothness, constant speed and complying with a minimum distance between vehicles, an approximate value function is iteratively developed to indicate the desirability of every state-action pair from the continuous state space and action space. The proposed scheme comprises two phases. The convergence of the value function takes place in the former learning phase, and it is then used as a path planning guideline in the subsequent action phase. This paper summarizes the concept and methodologies used to implement this online cooperative collision avoidance algorithm and presents results and analysis regarding how this cooperative scheme improves upon two baseline schemes where vehicles make movement decisions independently.

  12. The Relationships among Economic, Newsroom and Content Variables: A Path Model.

    Science.gov (United States)

    Lacy, Stephen; And Others

    Efforts to discover what variables affect news media content have taken many approaches during the past 35 years. These approaches have emphasized psychological factors, sociological factors, cultural and social forces, and economic factors. Evidence exists that all these forces play a role in determining what becomes news. To examine how these…

  13. Leavitt path algebras

    CERN Document Server

    Abrams, Gene; Siles Molina, Mercedes

    2017-01-01

    This book offers a comprehensive introduction by three of the leading experts in the field, collecting fundamental results and open problems in a single volume. Since Leavitt path algebras were first defined in 2005, interest in these algebras has grown substantially, with ring theorists as well as researchers working in graph C*-algebras, group theory and symbolic dynamics attracted to the topic. Providing a historical perspective on the subject, the authors review existing arguments, establish new results, and outline the major themes and ring-theoretic concepts, such as the ideal structure, Z-grading and the close link between Leavitt path algebras and graph C*-algebras. The book also presents key lines of current research, including the Algebraic Kirchberg Phillips Question, various additional classification questions, and connections to noncommutative algebraic geometry. Leavitt Path Algebras will appeal to graduate students and researchers working in the field and related areas, such as C*-algebras and...

  14. Paths correlation matrix.

    Science.gov (United States)

    Qian, Weixian; Zhou, Xiaojun; Lu, Yingcheng; Xu, Jiang

    2015-09-15

    Both the Jones and Mueller matrices encounter difficulties when physically modeling mixed materials or rough surfaces due to the complexity of light-matter interactions. To address these issues, we derived a matrix called the paths correlation matrix (PCM), which is a probabilistic mixture of Jones matrices of every light propagation path. Because PCM is related to actual light propagation paths, it is well suited for physical modeling. Experiments were performed, and the reflection PCM of a mixture of polypropylene and graphite was measured. The PCM of the mixed sample was accurately decomposed into pure polypropylene's single reflection, pure graphite's single reflection, and depolarization caused by multiple reflections, which is consistent with the theoretical derivation. Reflection parameters of rough surface can be calculated from PCM decomposition, and the results fit well with the theoretical calculations provided by the Fresnel equations. These theoretical and experimental analyses verify that PCM is an efficient way to physically model light-matter interactions.

  15. Techniques and applications of path integration

    CERN Document Server

    Schulman, L S

    2005-01-01

    A book of techniques and applications, this text defines the path integral and illustrates its uses by example. It is suitable for advanced undergraduates and graduate students in physics; its sole prerequisite is a first course in quantum mechanics. For applications requiring specialized knowledge, the author supplies background material.The first part of the book develops the techniques of path integration. Topics include probability amplitudes for paths and the correspondence limit for the path integral; vector potentials; the Ito integral and gauge transformations; free particle and quadra

  16. Joint modeling of constrained path enumeration and path choice behavior: a semi-compensatory approach

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    2010-01-01

    A behavioural and a modelling framework are proposed for representing route choice from a path set that satisfies travellers’ spatiotemporal constraints. Within the proposed framework, travellers’ master sets are constructed by path generation, consideration sets are delimited according to spatio...

  17. Paths and partitions: Combinatorial descriptions of the parafermionic states

    Science.gov (United States)

    Mathieu, Pierre

    2009-09-01

    The Zk parafermionic conformal field theories, despite the relative complexity of their modes algebra, offer the simplest context for the study of the bases of states and their different combinatorial representations. Three bases are known. The classic one is given by strings of the fundamental parafermionic operators whose sequences of modes are in correspondence with restricted partitions with parts at distance k -1 differing at least by 2. Another basis is expressed in terms of the ordered modes of the k -1 different parafermionic fields, which are in correspondence with the so-called multiple partitions. Both types of partitions have a natural (Bressoud) path representation. Finally, a third basis, formulated in terms of different paths, is inherited from the solution of the restricted solid-on-solid model of Andrews-Baxter-Forrester. The aim of this work is to review, in a unified and pedagogical exposition, these four different combinatorial representations of the states of the Zk parafermionic models. The first part of this article presents the different paths and partitions and their bijective relations; it is purely combinatorial, self-contained, and elementary; it can be read independently of the conformal-field-theory applications. The second part links this combinatorial analysis with the bases of states of the Zk parafermionic theories. With the prototypical example of the parafermionic models worked out in detail, this analysis contributes to fix some foundations for the combinatorial study of more complicated theories. Indeed, as we briefly indicate in ending, generalized versions of both the Bressoud and the Andrews-Baxter-Forrester paths emerge naturally in the description of the minimal models.

  18. Supermathematics and its applications in statistical physics Grassmann variables and the method of supersymmetry

    CERN Document Server

    Wegner, Franz

    2016-01-01

    This text presents the mathematical concepts of Grassmann variables and the method of supersymmetry to a broad audience of physicists interested in applying these tools to disordered and critical systems, as well as related topics in statistical physics. Based on many courses and seminars held by the author, one of the pioneers in this field, the reader is given a systematic and tutorial introduction to the subject matter. The algebra and analysis of Grassmann variables is presented in part I. The mathematics of these variables is applied to a random matrix model, path integrals for fermions, dimer models and the Ising model in two dimensions. Supermathematics - the use of commuting and anticommuting variables on an equal footing - is the subject of part II. The properties of supervectors and supermatrices, which contain both commuting and Grassmann components, are treated in great detail, including the derivation of integral theorems. In part III, supersymmetric physical models are considered. While supersym...

  19. Variability of Travel Times on New Jersey Highways

    Science.gov (United States)

    2011-06-01

    This report presents the results of a link and path travel time study conducted on selected New Jersey (NJ) highways to produce estimates of the corresponding variability of travel time (VTT) by departure time of the day and days of the week. The tra...

  20. A path integral approach to the Hodgkin-Huxley model

    Science.gov (United States)

    Baravalle, Roman; Rosso, Osvaldo A.; Montani, Fernando

    2017-11-01

    To understand how single neurons process sensory information, it is necessary to develop suitable stochastic models to describe the response variability of the recorded spike trains. Spikes in a given neuron are produced by the synergistic action of sodium and potassium of the voltage-dependent channels that open or close the gates. Hodgkin and Huxley (HH) equations describe the ionic mechanisms underlying the initiation and propagation of action potentials, through a set of nonlinear ordinary differential equations that approximate the electrical characteristics of the excitable cell. Path integral provides an adequate approach to compute quantities such as transition probabilities, and any stochastic system can be expressed in terms of this methodology. We use the technique of path integrals to determine the analytical solution driven by a non-Gaussian colored noise when considering the HH equations as a stochastic system. The different neuronal dynamics are investigated by estimating the path integral solutions driven by a non-Gaussian colored noise q. More specifically we take into account the correlational structures of the complex neuronal signals not just by estimating the transition probability associated to the Gaussian approach of the stochastic HH equations, but instead considering much more subtle processes accounting for the non-Gaussian noise that could be induced by the surrounding neural network and by feedforward correlations. This allows us to investigate the underlying dynamics of the neural system when different scenarios of noise correlations are considered.

  1. Análise de trilha em caracteres produtivos de Pennisetum sob corte em Itambé, Pernambuco Path analysis in productive characters of Pennisetum under cut in Itambé-PE

    Directory of Open Access Journals (Sweden)

    Mônica Alixandrina da Silva

    2008-07-01

    Full Text Available Objetivou-se obter estimativas de coeficientes de correlação genética e avaliar os desdobramentos das correlações em efeitos diretos e indiretos (análise de trilha das variáveis independentes explicativas sobre a produção de matéria seca (variável dependente principal em cinco clones de capim-elefante. Foram realizados cinco cortes a cada 60 dias nas condições edafoclimáticas da Zona da Mata de Pernambuco. Cada parcela experimental apresentou 24 m², com 2 m² de área útil. Houve alta correlação entre quase todas as variáveis explicativas e a variável principal. Entretanto, a característica número de lâminas foliares por perfilho explicou melhor o potencial de produção de matéria seca e atuou de forma direta e indireta sobre as variáveis explicativas.This work aimed to estimate the correlation coefficients, determining the direct and indirect effects (path analysis of explanatory independent variables on total dry matter production (main dependent variables of five elephant grass clones in five cuts accomplished at the forest zone of Pernambuco. Each experimental plot measured 24 m² with 2 m² of utile area. There was high correlation between almost all the independent variables and the main variable. The characteristic leaf blade number per tiller, however, explained better the potential of dry matter production and leaf blade dry matter production, acting, respectively, in a direct and indirect way on the explanatory variables.

  2. Travel path and transport mode identification method using ''less-frequently-detected'' position data

    International Nuclear Information System (INIS)

    Shimizu, T; Yamaguchi, T; Ai, H; Katagiri, Y; Kawase, J

    2014-01-01

    This study aims to seek method on travel path and transport mode identification in case positions of travellers are detected in low frequency. The survey in which ten test travellers with GPS logger move around Tokyo city centre was conducted. Travel path datasets of each traveller in which position data are selected every five minutes are processed from our survey data. Coverage index analysis based on the buffer analysis using GIS software is conducted. The condition and possibility to identify a path and a transport mode used are discussed

  3. Thermodynamic consistency of viscoplastic material models involving external variable rates in the evolution equations for the internal variables

    International Nuclear Information System (INIS)

    Malmberg, T.

    1993-09-01

    The objective of this study is to derive and investigate thermodynamic restrictions for a particular class of internal variable models. Their evolution equations consist of two contributions: the usual irreversible part, depending only on the present state, and a reversible but path dependent part, linear in the rates of the external variables (evolution equations of ''mixed type''). In the first instance the thermodynamic analysis is based on the classical Clausius-Duhem entropy inequality and the Coleman-Noll argument. The analysis is restricted to infinitesimal strains and rotations. The results are specialized and transferred to a general class of elastic-viscoplastic material models. Subsequently, they are applied to several viscoplastic models of ''mixed type'', proposed or discussed in the literature (Robinson et al., Krempl et al., Freed et al.), and it is shown that some of these models are thermodynamically inconsistent. The study is closed with the evaluation of the extended Clausius-Duhem entropy inequality (concept of Mueller) where the entropy flux is governed by an assumed constitutive equation in its own right; also the constraining balance equations are explicitly accounted for by the method of Lagrange multipliers (Liu's approach). This analysis is done for a viscoplastic material model with evolution equations of the ''mixed type''. It is shown that this approach is much more involved than the evaluation of the classical Clausius-Duhem entropy inequality with the Coleman-Noll argument. (orig.) [de

  4. Representing general theoretical concepts in structural equation models: The role of composite variables

    Science.gov (United States)

    Grace, J.B.; Bollen, K.A.

    2008-01-01

    Structural equation modeling (SEM) holds the promise of providing natural scientists the capacity to evaluate complex multivariate hypotheses about ecological systems. Building on its predecessors, path analysis and factor analysis, SEM allows for the incorporation of both observed and unobserved (latent) variables into theoretically-based probabilistic models. In this paper we discuss the interface between theory and data in SEM and the use of an additional variable type, the composite. In simple terms, composite variables specify the influences of collections of other variables and can be helpful in modeling heterogeneous concepts of the sort commonly of interest to ecologists. While long recognized as a potentially important element of SEM, composite variables have received very limited use, in part because of a lack of theoretical consideration, but also because of difficulties that arise in parameter estimation when using conventional solution procedures. In this paper we present a framework for discussing composites and demonstrate how the use of partially-reduced-form models can help to overcome some of the parameter estimation and evaluation problems associated with models containing composites. Diagnostic procedures for evaluating the most appropriate and effective use of composites are illustrated with an example from the ecological literature. It is argued that an ability to incorporate composite variables into structural equation models may be particularly valuable in the study of natural systems, where concepts are frequently multifaceted and the influence of suites of variables are often of interest. ?? Springer Science+Business Media, LLC 2007.

  5. Isomorphisms and traversability of directed path graphs

    NARCIS (Netherlands)

    Broersma, Haitze J.; Li, Xueliang; Li, X.

    1998-01-01

    The concept of a line digraph is generalized to that of a directed path graph. The directed path graph $\\forw P_k(D)$ of a digraph $D$ is obtained by representing the directed paths on $k$ vertices of $D$ by vertices. Two vertices are joined by an arc whenever the corresponding directed paths in $D$

  6. PATH COEFFICIENT ANALYSIS OF SEVERAL COMPONENTS OIL YIELD IN SUNFLOWER (HELIANTHUS ANNUUS L.

    Directory of Open Access Journals (Sweden)

    A. MIjić

    2006-06-01

    Full Text Available The objective of investigation was to analyse oil yield components and their relations by simple coefficient correlations as well as direct and indirect effects to oil yield by path analysis. Twenty-four sunflower hybrids were included in the investigation and their seven traits (plant height, head diameter, 1000 seed weight, hec- tolitar mass, grain yield, oil content and oil yield. Very strong positive correlation was estimated between grain yield and oil yield, strong positive correlation between hectolitar mass and oil yield, and middle corre- lation among oil yield and: 1000 seed weight, plaint height and oil content. There was no correlation between grain yields and oil content. Grain yield showed the strongest effect to oil yield. Oil content had lower effect to oil yield. Other traits showed no significant effect to oil yield, and their effect to oil yield was covered by indirect effect of grain yield.

  7. A Variable Stiffness Analysis Model for Large Complex Thin-Walled Guide Rail

    Directory of Open Access Journals (Sweden)

    Wang Xiaolong

    2016-01-01

    Full Text Available Large complex thin-walled guide rail has complicated structure and no uniform low rigidity. The traditional cutting simulations are time consuming due to huge computation especially in large workpiece. To solve these problems, a more efficient variable stiffness analysis model has been propose, which can obtain quantitative stiffness value of the machining surface. Applying simulate cutting force in sampling points using finite element analysis software ABAQUS, the single direction variable stiffness rule can be obtained. The variable stiffness matrix has been propose by analyzing multi-directions coupling variable stiffness rule. Combining with the three direction cutting force value, the reasonability of existing processing parameters can be verified and the optimized cutting parameters can be designed.

  8. Analysis of an Automated Vehicle Routing Problem in Logistics considering Path Interruption

    Directory of Open Access Journals (Sweden)

    Yong Zhang

    2017-01-01

    Full Text Available The application of automated vehicles in logistics can efficiently reduce the cost of logistics and reduce the potential risks in the last mile. Considering the path restriction in the initial stage of the application of automated vehicles in logistics, the conventional model for a vehicle routing problem (VRP is modified. Thus, the automated vehicle routing problem with time windows (AVRPTW model considering path interruption is established. Additionally, an improved particle swarm optimisation (PSO algorithm is designed to solve this problem. Finally, a case study is undertaken to test the validity of the model and the algorithm. Four automated vehicles are designated to execute all delivery tasks required by 25 stores. Capacities of all of the automated vehicles are almost fully utilised. It is of considerable significance for the promotion of automated vehicles in last-mile situations to develop such research into real problems arising in the initial period.

  9. [Relations between biomedical variables: mathematical analysis or linear algebra?].

    Science.gov (United States)

    Hucher, M; Berlie, J; Brunet, M

    1977-01-01

    The authors, after a short reminder of one pattern's structure, stress on the possible double approach of relations uniting the variables of this pattern: use of fonctions, what is within the mathematical analysis sphere, use of linear algebra profiting by matricial calculation's development and automatiosation. They precise the respective interests on these methods, their bounds and the imperatives for utilization, according to the kind of variables, of data, and the objective for work, understanding phenomenons or helping towards decision.

  10. Path length entropy analysis of diastolic heart sounds.

    Science.gov (United States)

    Griffel, Benjamin; Zia, Mohammad K; Fridman, Vladamir; Saponieri, Cesare; Semmlow, John L

    2013-09-01

    Early detection of coronary artery disease (CAD) using the acoustic approach, a noninvasive and cost-effective method, would greatly improve the outcome of CAD patients. To detect CAD, we analyze diastolic sounds for possible CAD murmurs. We observed diastolic sounds to exhibit 1/f structure and developed a new method, path length entropy (PLE) and a scaled version (SPLE), to characterize this structure to improve CAD detection. We compare SPLE results to Hurst exponent, Sample entropy and Multiscale entropy for distinguishing between normal and CAD patients. SPLE achieved a sensitivity-specificity of 80%-81%, the best of the tested methods. However, PLE and SPLE are not sufficient to prove nonlinearity, and evaluation using surrogate data suggests that our cardiovascular sound recordings do not contain significant nonlinear properties. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. A path-integral approach for bosonic effective theories for Fermion fields in four and three dimensions

    International Nuclear Information System (INIS)

    Botelho, Luiz C.L.

    1998-02-01

    We study four dimensional Effective Bosonic Field Theories for massive fermion field in the infrared region and massive fermion in ultraviolet region by using an appropriate Fermion Path Integral Chiral variable change and the Polyakov's Fermi-Bose transmutation in the 3D-Abelian Thrirring model. (author)

  12. Career paths in physicians' postgraduate training - an eight-year follow-up study.

    Science.gov (United States)

    Buddeberg-Fischer, Barbara; Stamm, Martina; Klaghofer, Richard

    2010-10-06

    To date, there are hardly any studies on the choice of career path in medical school graduates. The present study aimed to investigate what career paths can be identified in the course of postgraduate training of physicians; what factors have an influence on the choice of a career path; and in what way the career paths are correlated with career-related factors as well as with work-life balance aspirations. The data reported originates from five questionnaire surveys of the prospective SwissMedCareer Study, beginning in 2001 (T1, last year of medical school). The study sample consisted of 358 physicians (197 females, 55%; 161 males, 45%) participating at each assessment from T2 (2003, first year of residency) to T5 (2009, seventh year of residency), answering the question: What career do you aspire to have? Furthermore, personal characteristics, chosen specialty, career motivation, mentoring experience, work-life balance as well as workload, career success and career satisfaction were assessed. Career paths were analysed with cluster analysis, and differences between clusters analysed with multivariate methods. The cluster analysis revealed four career clusters which discriminated distinctly between each other: (1) career in practice, (2) hospital career, (3) academic career, and (4) changing career goal. From T3 (third year of residency) to T5, respondents in Cluster 1-3 were rather stable in terms of their career path aspirations, while those assigned to Cluster 4 showed a high fluctuation in their career plans. Physicians in Cluster 1 showed high values in extraprofessional concerns and often consider part-time work. Cluster 2 and 3 were characterised by high instrumentality, intrinsic and extrinsic career motivation, career orientation and high career success. No cluster differences were seen in career satisfaction. In Cluster 1 and 4, females were overrepresented. Trainees should be supported to stay on the career path that best suits his/her personal and

  13. GIS and correlation analysis of geo-environmental variables ...

    African Journals Online (AJOL)

    GIS and correlation analysis of geo-environmental variables influencing malaria prevalence in the Saboba district of Northern Ghana. ... The study also applied spline interpolation technique to map malaria prevalence in the district using standardised malaria incidence. The result indicates that distance to marshy areas is ...

  14. Moisture Risk in Unvented Attics Due to Air Leakage Paths

    Energy Technology Data Exchange (ETDEWEB)

    Prahl, D.; Shaffer, M.

    2014-11-01

    IBACOS completed an initial analysis of moisture damage potential in an unvented attic insulated with closed-cell spray polyurethane foam. To complete this analysis, the research team collected field data, used computational fluid dynamics to quantify the airflow rates through individual airflow (crack) paths, simulated hourly flow rates through the leakage paths with CONTAM software, correlated the CONTAM flow rates with indoor humidity ratios from Building Energy Optimization software, and used Warme und Feuchte instationar Pro two-dimensional modeling to determine the moisture content of the building materials surrounding the cracks. Given the number of simplifying assumptions and numerical models associated with this analysis, the results indicate that localized damage due to high moisture content of the roof sheathing is possible under very low airflow rates. Reducing the number of assumptions and approximations through field studies and laboratory experiments would be valuable to understand the real-world moisture damage potential in unvented attics.

  15. Moisture Risk in Unvented Attics Due to Air Leakage Paths

    Energy Technology Data Exchange (ETDEWEB)

    Prahl, D. [IBACOS, Inc., Pittsburgh, PA (United States); Shaffer, M. [IBACOS, Inc., Pittsburgh, PA (United States)

    2014-11-01

    IBACOS completed an initial analysis of moisture damage potential in an unvented attic insulated with closed-cell spray polyurethane foam. To complete this analysis, the research team collected field data, used computational fluid dynamics to quantify the airflow rates through individual airflow (crack) paths, simulated hourly flow rates through the leakage paths with CONTAM software, correlated the CONTAM flow rates with indoor humidity ratios from Building Energy Optimization software, and used Wärme und Feuchte instationär Pro two-dimensional modeling to determine the moisture content of the building materials surrounding the cracks. Given the number of simplifying assumptions and numerical models associated with this analysis, the results indicate that localized damage due to high moisture content of the roof sheathing is possible under very low airflow rates. Reducing the number of assumptions and approximations through field studies and laboratory experiments would be valuable to understand the real-world moisture damage potential in unvented attics.

  16. Graphs with not all possible path-kernels

    DEFF Research Database (Denmark)

    Aldred, Robert; Thomassen, Carsten

    2004-01-01

    The Path Partition Conjecture states that the vertices of a graph G with longest path of length c may be partitioned into two parts X and Y such that the longest path in the subgraph of G induced by X has length at most a and the longest path in the subgraph of G induced by Y has length at most b...

  17. Design of Active N-path Filters

    NARCIS (Netherlands)

    Darvishi, M.; van der Zee, Ronan A.R.; Nauta, Bram

    2013-01-01

    A design methodology for synthesis of active N-path bandpass filters is introduced. Based on this methodology, a 0.1-to-1.2 GHz tunable 6th-order N-path channel-select filter in 65 nm LP CMOS is introduced. It is based on coupling N-path filters with gyrators, achieving a “flat‿ passband shape and

  18. AN IMPROVEMENT ON GEOMETRY-BASED METHODS FOR GENERATION OF NETWORK PATHS FROM POINTS

    Directory of Open Access Journals (Sweden)

    Z. Akbari

    2014-10-01

    Full Text Available Determining network path is important for different purposes such as determination of road traffic, the average speed of vehicles, and other network analysis. One of the required input data is information about network path. Nevertheless, the data collected by the positioning systems often lead to the discrete points. Conversion of these points to the network path have become one of the challenges which different researchers, presents many ways for solving it. This study aims at investigating geometry-based methods to estimate the network paths from the obtained points and improve an existing point to curve method. To this end, some geometry-based methods have been studied and an improved method has been proposed by applying conditions on the best method after describing and illustrating weaknesses of them.

  19. Path integrals and geometry of trajectories

    International Nuclear Information System (INIS)

    Blau, M.; Keski-Vakkuri, E.; Niemi, A.J.

    1990-01-01

    A geometrical interpretation of path integrals is developed in the space of trajectories. This yields a supersymmetric formulation of a generic path integral, with the supersymmetry resembling the BRST supersymmetry of a first class constrained system. If the classical equation of motion is a Killing vector field in the space of trajectories, the supersymmetry localizes the path integral to classical trajectories and the WKB approximation becomes exact. This can be viewed as a path integral generalization of the Duistermaat-Heckman theorem, which states the conditions for the exactness of the WKB approximation for integrals in a compact phase space. (orig.)

  20. Vibrational analysis of a shipboard free electron laser beam path

    OpenAIRE

    Gallant, Bryan M.

    2011-01-01

    This thesis explores the deployment of a free electron laser (FEL) weapon system in a shipboard vibration environment. A concept solid model of a shipboard FEL is developed and used as a basis for a finite element model which is subjected to vibration simulation in MATLAB. Vibration input is obtained from ship shock trials data and wave excited motion data from ship motion simulation software. Emphasis is placed on the motion of electron beam path components of the FEL and the feasibility of ...

  1. Civil Society and Paths to Abolition

    Directory of Open Access Journals (Sweden)

    Seymour DRESCHER

    2015-12-01

    Full Text Available Abstract Through a comparative analysis, this article aims to present an overview of British, French, Russian, American and Brazilian abolitionist action, between the late eighteenth century and throughout the nineteenth century. Indicating the struggles of pro-abolition civil associations, the paths taken in Britain, France, the US and Brazil are presented in parallel - either to emphasize approaches, either to highlight the undeniable peculiarities - revealing the marks of violence and negotiation present in the emancipation process.

  2. AN INVESTIGATION ON RELATION AND PREDICTION OF PERCEIVED ORGANIZATIONAL SUPPORT (POS ACCORDING TO 15 FOLD ORGANIZATIONAL VARIABLES

    Directory of Open Access Journals (Sweden)

    Hassan DARVISH

    2012-01-01

    Full Text Available The aim of this article is to study the relation between perceived organizational support(POS with 15 fold variables including cooperation in decision making, servicing the public, job vision, trust to supervisor, satisfaction with salary, promotion opportunity, inner provocation, quality of supervising, desire to remain, leaving the job, organizational trust, job interest, satisfaction with supervisor and satisfaction with colleagues. In order to achieve the foregoing aim, there were 198 people selected from all employed personnel in Rahpooyan Company and answered the questionnaires. The document related to validity and reliability of this investigation means were in an acceptable level. The data collected from these questionnaires was analysed via coefficient of Pierson correlation, analysis of step by step regression, analysis of structural equation (path analysis. The results indicate there was a significant correlation between perceived organizational support and including cooperation in decision making, servicing the public, job vision, trust to supervisor, satisfaction with salary, promotion opportunity, quality of supervising, desire to remain, leaving the job, organizational trust, satisfaction with supervisor and satisfaction with colleagues. But there was no significant correlation between inner provocation and job interest with perceived organizational support. In analysis of step by step regression, it was also indicated that cooperation in decision making, promotion opportunity, trust to supervisor, job interest and organizational trust can specify about 56% of the perceived organizational support variance. The results of the path analysis also indicated that cooperation in decision making, promotion opportunity, trust to supervisor, job interest have a coefficient of direct path on perceived organizational support.

  3. Perfect discretization of path integrals

    International Nuclear Information System (INIS)

    Steinhaus, Sebastian

    2012-01-01

    In order to obtain a well-defined path integral one often employs discretizations. In the case of General Relativity these generically break diffeomorphism symmetry, which has severe consequences since these symmetries determine the dynamics of the corresponding system. In this article we consider the path integral of reparametrization invariant systems as a toy example and present an improvement procedure for the discretized propagator. Fixed points and convergence of the procedure are discussed. Furthermore we show that a reparametrization invariant path integral implies discretization independence and acts as a projector onto physical states.

  4. Perfect discretization of path integrals

    Science.gov (United States)

    Steinhaus, Sebastian

    2012-05-01

    In order to obtain a well-defined path integral one often employs discretizations. In the case of General Relativity these generically break diffeomorphism symmetry, which has severe consequences since these symmetries determine the dynamics of the corresponding system. In this article we consider the path integral of reparametrization invariant systems as a toy example and present an improvement procedure for the discretized propagator. Fixed points and convergence of the procedure are discussed. Furthermore we show that a reparametrization invariant path integral implies discretization independence and acts as a projector onto physical states.

  5. Insights into gait disorders: walking variability using phase plot analysis, Huntington's disease.

    Science.gov (United States)

    Collett, Johnny; Esser, Patrick; Khalil, Hanan; Busse, Monica; Quinn, Lori; DeBono, Katy; Rosser, Anne; Nemeth, Andrea H; Dawes, Helen

    2014-09-01

    Huntington's disease (HD) is a progressive inherited neurodegenerative disorder. Identifying sensitive methodologies to quantitatively measure early motor changes have been difficult to develop. This exploratory observational study investigated gait variability and symmetry in HD using phase plot analysis. We measured the walking of 22 controls and 35 HD gene carriers (7 premanifest (PreHD)), 16 early/mid (HD1) and 12 late stage (HD2) in Oxford and Cardiff, UK. The unified Huntington's disease rating scale-total motor scores (UHDRS-TMS) and disease burden scores (DBS) were used to quantify disease severity. Data was collected during a clinical walk test (8.8 or 10 m) using an inertial measurement unit attached to the trunk. The 6 middle strides were used to calculate gait variability determined by spatiotemporal parameters (co-efficient of variation (CoV)) and phase plot analysis. Phase plots considered the variability in consecutive wave forms from vertical movement and were quantified by SDA (spatiotemporal variability), SDB (temporal variability), ratio ∀ (ratio SDA:SDB) and Δangleβ (symmetry). Step time CoV was greater in manifest HD (p0.05). Phase plot analysis identified differences between manifest HD and controls for SDB, Ratio ∀ and Δangle (all pplot analysis may be a sensitive method of detecting gait changes in HD and can be performed quickly during clinical walking tests. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Downstream wind flow path diversion and its effects on the performance of vertical axis wind turbine

    International Nuclear Information System (INIS)

    Maganhar, A.L.

    2015-01-01

    In the present experimental study efforts have been made to analysis path diversion effect of downstream wind flow on performance of vertical axis wind turbine (VAWT). For the blockage of downstream wind flow path at various linear displaced positions, a normal erected flat wall, semi-circular and cylindrical shapes were tested for path diverting geometries. Performance of VAWT in terms of improved rotor speed up to 45% was achieved. (author)

  7. Evaluating Status Change of Soil Potassium from Path Model

    Science.gov (United States)

    He, Wenming; Chen, Fang

    2013-01-01

    The purpose of this study is to determine critical environmental parameters of soil K availability and to quantify those contributors by using a proposed path model. In this study, plot experiments were designed into different treatments, and soil samples were collected and further analyzed in laboratory to investigate soil properties influence on soil potassium forms (water soluble K, exchangeable K, non-exchangeable K). Furthermore, path analysis based on proposed path model was carried out to evaluate the relationship between potassium forms and soil properties. Research findings were achieved as followings. Firstly, key direct factors were soil S, ratio of sodium-potassium (Na/K), the chemical index of alteration (CIA), Soil Organic Matter in soil solution (SOM), Na and total nitrogen in soil solution (TN), and key indirect factors were Carbonate (CO3), Mg, pH, Na, S, and SOM. Secondly, path model can effectively determine direction and quantities of potassium status changes between Exchangeable potassium (eK), Non-exchangeable potassium (neK) and water-soluble potassium (wsK) under influences of specific environmental parameters. In reversible equilibrium state of , K balance state was inclined to be moved into β and χ directions in treatments of potassium shortage. However in reversible equilibrium of , K balance state was inclined to be moved into θ and λ directions in treatments of water shortage. Results showed that the proposed path model was able to quantitatively disclose moving direction of K status and quantify its equilibrium threshold. It provided a theoretical and practical basis for scientific and effective fertilization in agricultural plants growth. PMID:24204659

  8. Detection of deregulated modules using deregulatory linked path.

    Directory of Open Access Journals (Sweden)

    Yuxuan Hu

    Full Text Available The identification of deregulated modules (such as induced by oncogenes is a crucial step for exploring the pathogenic process of complex diseases. Most of the existing methods focus on deregulation of genes rather than the links of the path among them. In this study, we emphasize on the detection of deregulated links, and develop a novel and effective regulatory path-based approach in finding deregulated modules. Observing that a regulatory pathway between two genes might involve in multiple rather than a single path, we identify condition-specific core regulatory path (CCRP to detect the significant deregulation of regulatory links. Using time-series gene expression, we define the regulatory strength within each gene pair based on statistical dependence analysis. The CCRPs in regulatory networks can then be identified using the shortest path algorithm. Finally, we derive the deregulated modules by integrating the differential edges (as deregulated links of the CCRPs between the case and the control group. To demonstrate the effectiveness of our approach, we apply the method to expression data associated with different states of Human Epidermal Growth Factor Receptor 2 (HER2. The experimental results show that the genes as well as the links in the deregulated modules are significantly enriched in multiple KEGG pathways and GO biological processes, most of which can be validated to suffer from impact of this oncogene based on previous studies. Additionally, we find the regulatory mechanism associated with the crucial gene SNAI1 significantly deregulated resulting from the activation of HER2. Hence, our method provides not only a strategy for detecting the deregulated links in regulatory networks, but also a way to identify concerning deregulated modules, thus contributing to the target selection of edgetic drugs.

  9. On Hilbert space of paths

    International Nuclear Information System (INIS)

    Exner, P.; Kolerov, G.I.

    1980-01-01

    A Hilbert space of paths, the elements of which are determined by trigonometric series, was proposed and used recently by Truman. This space is shown to consist precisely of all absolutely continuous paths ending in the origin with square-integrable derivatives

  10. Crack path predictions and experiments in plane structures considering anisotropic properties and material interfaces

    Directory of Open Access Journals (Sweden)

    P.O. Judt

    2015-10-01

    Full Text Available In many engineering applications special requirements are directed to a material's fracture behavior and the prediction of crack paths. Especially if the material exhibits anisotropic elastic properties or fracture toughnesses, e.g. in textured or composite materials, the simulation of crack paths is challenging. Here, the application of path independent interaction integrals (I-integrals, J-, L- and M-integrals is beneficial for an accurate crack tip loading analysis. Numerical tools for the calculation of loading quantities using these path-invariant integrals are implemented into the commercial finite element (FE-code ABAQUS. Global approaches of the integrals are convenient considering crack tips approaching other crack faces, internal boundaries or material interfaces. Curved crack faces require special treatment with respect to integration contours. Numerical crack paths are predicted based on FE calculations of the boundary value problem in connection with an intelligent adaptive re-meshing algorithm. Considering fracture toughness anisotropy and accounting for inelastic effects due to small plastic zones in the crack tip region, the numerically predicted crack paths of different types of specimens with material interfaces and internal boundaries are compared to subcritically grown paths obtained from experiments.

  11. cPath: open source software for collecting, storing, and querying biological pathways

    Directory of Open Access Journals (Sweden)

    Gross Benjamin E

    2006-11-01

    Full Text Available Abstract Background Biological pathways, including metabolic pathways, protein interaction networks, signal transduction pathways, and gene regulatory networks, are currently represented in over 220 diverse databases. These data are crucial for the study of specific biological processes, including human diseases. Standard exchange formats for pathway information, such as BioPAX, CellML, SBML and PSI-MI, enable convenient collection of this data for biological research, but mechanisms for common storage and communication are required. Results We have developed cPath, an open source database and web application for collecting, storing, and querying biological pathway data. cPath makes it easy to aggregate custom pathway data sets available in standard exchange formats from multiple databases, present pathway data to biologists via a customizable web interface, and export pathway data via a web service to third-party software, such as Cytoscape, for visualization and analysis. cPath is software only, and does not include new pathway information. Key features include: a built-in identifier mapping service for linking identical interactors and linking to external resources; built-in support for PSI-MI and BioPAX standard pathway exchange formats; a web service interface for searching and retrieving pathway data sets; and thorough documentation. The cPath software is freely available under the LGPL open source license for academic and commercial use. Conclusion cPath is a robust, scalable, modular, professional-grade software platform for collecting, storing, and querying biological pathways. It can serve as the core data handling component in information systems for pathway visualization, analysis and modeling.

  12. Tool path in torus tool CNC machining

    Directory of Open Access Journals (Sweden)

    XU Ying

    2016-10-01

    Full Text Available This paper is about tool path in torus tool CNC machining.The mathematical model of torus tool is established.The tool path planning algorithm is determined through calculation of the cutter location,boundary discretization,calculation of adjacent tool path and so on,according to the conversion formula,the cutter contact point will be converted to the cutter location point and then these points fit a toolpath.Lastly,the path planning algorithm is implemented by using Matlab programming.The cutter location points for torus tool are calculated by Matlab,and then fit these points to a toolpath.While using UG software,another tool path of free surface is simulated of the same data.It is drew compared the two tool paths that using torus tool is more efficient.

  13. Path Creation

    DEFF Research Database (Denmark)

    Karnøe, Peter; Garud, Raghu

    2012-01-01

    This paper employs path creation as a lens to follow the emergence of the Danish wind turbine cluster. Supplier competencies, regulations, user preferences and a market for wind power did not pre-exist; all had to emerge in a tranformative manner involving multiple actors and artefacts. Competenc......This paper employs path creation as a lens to follow the emergence of the Danish wind turbine cluster. Supplier competencies, regulations, user preferences and a market for wind power did not pre-exist; all had to emerge in a tranformative manner involving multiple actors and artefacts....... Competencies emerged through processes and mechanisms such as co-creation that implicated multiple learning processes. The process was not an orderly linear one as emergent contingencies influenced the learning processes. An implication is that public policy to catalyse clusters cannot be based...

  14. Interactive multi-objective path planning through a palette-based user interface

    Science.gov (United States)

    Shaikh, Meher T.; Goodrich, Michael A.; Yi, Daqing; Hoehne, Joseph

    2016-05-01

    n a problem where a human uses supervisory control to manage robot path-planning, there are times when human does the path planning, and if satisfied commits those paths to be executed by the robot, and the robot executes that plan. In planning a path, the robot often uses an optimization algorithm that maximizes or minimizes an objective. When a human is assigned the task of path planning for robot, the human may care about multiple objectives. This work proposes a graphical user interface (GUI) designed for interactive robot path-planning when an operator may prefer one objective over others or care about how multiple objectives are traded off. The GUI represents multiple objectives using the metaphor of an artist's palette. A distinct color is used to represent each objective, and tradeoffs among objectives are balanced in a manner that an artist mixes colors to get the desired shade of color. Thus, human intent is analogous to the artist's shade of color. We call the GUI an "Adverb Palette" where the word "Adverb" represents a specific type of objective for the path, such as the adverbs "quickly" and "safely" in the commands: "travel the path quickly", "make the journey safely". The novel interactive interface provides the user an opportunity to evaluate various alternatives (that tradeoff between different objectives) by allowing her to visualize the instantaneous outcomes that result from her actions on the interface. In addition to assisting analysis of various solutions given by an optimization algorithm, the palette has additional feature of allowing the user to define and visualize her own paths, by means of waypoints (guiding locations) thereby spanning variety for planning. The goal of the Adverb Palette is thus to provide a way for the user and robot to find an acceptable solution even though they use very different representations of the problem. Subjective evaluations suggest that even non-experts in robotics can carry out the planning tasks with a

  15. MODIFIED PATH METHODOLOGY FOR OBTAINING INTERVAL-SCALED POSTURAL ASSESSMENTS OF FARMWORKERS.

    Science.gov (United States)

    Garrison, Emma B; Dropkin, Jonathan; Russell, Rebecca; Jenkins, Paul

    2018-01-29

    Agricultural workers perform tasks that frequently require awkward and extreme postures that are associated with musculoskeletal disorders (MSDs). The PATH (Posture, Activity, Tools, Handling) system currently provides a sound methodology for quantifying workers' exposure to these awkward postures on an ordinal scale of measurement, which places restrictions on the choice of analytic methods. This study reports a modification of the PATH methodology that instead captures these postures as degrees of flexion, an interval-scaled measurement. Rather than making live observations in the field, as in PATH, the postural assessments were performed on photographs using ImageJ photo analysis software. Capturing the postures in photographs permitted more careful measurement of the degrees of flexion. The current PATH methodology requires that the observer in the field be trained in the use of PATH, whereas the single photographer used in this modification requires only sufficient training to maintain the proper camera angle. Ultimately, these interval-scale measurements could be combined with other quantitative measures, such as those produced by electromyograms (EMGs), to provide more sophisticated estimates of future risk for MSDs. Further, these data can provide a baseline from which the effects of interventions designed to reduce hazardous postures can be calculated with greater precision. Copyright© by the American Society of Agricultural Engineers.

  16. Study of development paths of dairy farmers in Slovenia

    NARCIS (Netherlands)

    Klopcic, M.; Verhees, F.J.H.M.; Kuipers, A.; Koops, W.J.

    2014-01-01

    As part of the Central and Eastern European project of Wageningen UR (Wageningen, the Netherlands) combined with a Leonardo da Vinci project coordinated by Warsaw University of Life Sciences (Warsaw, Poland), an analysis was performed in year 2012 of future development paths of dairy farmers in

  17. Path creation in Nordic energy and road transport systems – The role of technological characteristics

    DEFF Research Database (Denmark)

    Hansen, Teis; Klitkou, Antje; Borup, Mads

    2017-01-01

    This paper reviews path-creation processes in road transport systems in the Nordic countries: e-mobility in Denmark, hydrogen and fuel-cell electrical vehicles in Norway, and advanced biofuels in Finland and Sweden. The study builds on the path creation literature, which seeks to explain the emer......This paper reviews path-creation processes in road transport systems in the Nordic countries: e-mobility in Denmark, hydrogen and fuel-cell electrical vehicles in Norway, and advanced biofuels in Finland and Sweden. The study builds on the path creation literature, which seeks to explain...... the emergence of new technological pathways. Drawing on recent insights concerning the differences between design- and manufacturing-intensive technologies, the paper analyses the influence of technological characteristics on path creation processes. The case comparison indicates that technological...... characteristics seem to have greater influence on the content of activities in the later phase rather than the early phase of path creation processes. The analysis also emphasises that barriers to path creation processes differ depending on technological characteristics. This highlights the importance...

  18. Fractal analysis of crack paths in Al2O3-TiC-4%Co composites

    Institute of Scientific and Technical Information of China (English)

    LI Jing; YIN Yan-sheng; LIU Ying-cai; MA Lai-peng

    2006-01-01

    Al2O3-TiC-4%Co(volume fraction) composites(ATC) with high toughness (7.8±0.8 MPa·m1/2) and strength (782±60 MPa) were fabricated. In comparison with Al2O3-TiC composites(AT), the fracture toughness was significantly improved by 60%. The crack paths, generated by Vickers indentation on the polished surfaces of both composites, were analyzed from a fractal point of view to distinguish the possible toughening mechanisms involved. Quantitative evaluation of indentation cracks indicates that the crack deflection plays a more effective role. Cracks of the ATC composites show higher deflection angles and more deflections along the path. ATC composites present higher fractal dimension (D=1.07) than AT composites (D=1.02), which is directly related to the higher fracture toughness. A significant relationship between crack path and toughness is evident: the more irregular the geometry of the crack, the higher the fracture toughness.

  19. How to solve path integrals in quantum mechanics

    International Nuclear Information System (INIS)

    Grosche, C.

    1994-10-01

    A systematic classification of Feynman path integrals in quantum mechanics is presented and a table of solvable path integrals is given which reflects the progress made during the last 15 years, including, of course, the main contributions since the invention of the path integral by Feynman in 1942. An outline of the general theory is given which will serve as a quick reference for solving path integrals. Explicit formulae for the so-called basic path integrals are presented on which our general scheme to classify and calculate path integrals in quantum mechanics is based. (orig.)

  20. Shared Responsibility for Type 1 Diabetes Care Is Associated With Glycemic Variability and Risk of Glycemic Excursions in Youth.

    Science.gov (United States)

    Marker, Arwen M; Noser, Amy E; Clements, Mark A; Patton, Susana R

    2018-01-01

    We examined how parent and youth responsibility for type 1 diabetes (T1D) care is related to adherence and glycemic outcomes, namely, glycemic variability and risk of glycemic excursions. One hundred thirty-five parent-youth dyads (10-16 years old; diagnosed with T1D for at least 6 months) participated in this study. Percent responsibility of T1D care attributed to the youth, parent, or shared was measured using the Diabetes Family Responsibility Questionnaire. We collected youth's hemoglobin A1c (HbA1c) and glucometer downloads to examine relationships between responsibility and HbA1c, frequency of blood glucose monitoring (self-monitoring blood glucose, SMBG), risk of glycemic excursions, and actual glycemic variability using bivariate correlations and path analysis. Participants reported shared responsibility for almost half of T1D self-care tasks. Bivariate correlations showed shared responsibility was associated with less variability, whereas parent responsibility was associated with greater glycemic variability and risk for glycemic excursions. Youth responsibility was associated with lower frequency of SMBG. The path analyses confirmed our correlational findings (pshypothesis that shared T1D responsibility is associated with better diabetes outcomes in youth. © The Author 2017. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com