The Animal Model Determines the Results of Aeromonas Virulence Factors
Romero, Alejandro; Saraceni, Paolo R.; Merino, Susana; Figueras, Antonio; Tomás, Juan M.; Novoa, Beatriz
2016-01-01
The selection of an experimental animal model is of great importance in the study of bacterial virulence factors. Here, a bath infection of zebrafish larvae is proposed as an alternative model to study the virulence factors of Aeromonas hydrophila. Intraperitoneal infections in mice and trout were compared with bath infections in zebrafish larvae using specific mutants. The great advantage of this model is that bath immersion mimics the natural route of infection, and injury to the tail also provides a natural portal of entry for the bacteria. The implication of T3SS in the virulence of A. hydrophila was analyzed using the AH-1::aopB mutant. This mutant was less virulent than the wild-type strain when inoculated into zebrafish larvae, as described in other vertebrates. However, the zebrafish model exhibited slight differences in mortality kinetics only observed using invertebrate models. Infections using the mutant AH-1ΔvapA lacking the gene coding for the surface S-layer suggested that this protein was not totally necessary to the bacteria once it was inside the host, but it contributed to the inflammatory response. Only when healthy zebrafish larvae were infected did the mutant produce less mortality than the wild-type. Variations between models were evidenced using the AH-1ΔrmlB, which lacks the O-antigen lipopolysaccharide (LPS), and the AH-1ΔwahD, which lacks the O-antigen LPS and part of the LPS outer-core. Both mutants showed decreased mortality in all of the animal models, but the differences between them were only observed in injured zebrafish larvae, suggesting that residues from the LPS outer core must be important for virulence. The greatest differences were observed using the AH-1ΔFlaB-J (lacking polar flagella and unable to swim) and the AH-1::motX (non-motile but producing flagella). They were as pathogenic as the wild-type strain when injected into mice and trout, but no mortalities were registered in zebrafish larvae. This study demonstrates
Basset-Mens, Claudine; Anibar, Lamiaa; Durand, Patrick; van der Werf, Hayo M G
2006-08-15
The challenge for environmental assessment tools, such as Life Cycle Assessment (LCA) is to provide a holistic picture of the environmental impacts of a given system, while being relevant both at a global scale, i.e., for global impact categories such as climate change, and at a smaller scale, i.e., for regional impact categories such as aquatic eutrophication. To this end, the environmental mechanisms between emission and impact should be taken into account. For eutrophication in particular, which is one of the main impacts of farming systems, the fate factor of eutrophying pollutants in catchments, and particularly of nitrate, reflects one of these important and complex environmental mechanisms. We define this fate factor as: the ratio of the amount of nitrate at the outlet of the catchment over the nitrate emitted from the catchment's soils. In LCA, this fate factor is most often assumed equal to 1, while the observed fate factor is generally less than 1. A generic approach for estimating the range of variation of nitrate fate factors in a region of intensive agriculture was proposed. This approach was based on the analysis of different catchment scenarios combining different catchment types and different effective rainfalls. The evolution over time of the nitrate fate factor as well as the steady state fate factor for each catchment scenario was obtained using the INCA simulation model. In line with the general LCA model, the implications of the steady state fate factors for nitrate were investigated for the eutrophication impact result in the framework of an LCA of pig production. A sensitivity analysis to the fraction of nitrate lost as N(2)O was presented for the climate change impact category. This study highlighted the difference between the observed fate factor at a given time, which aggregates both storage and transformation processes and a "steady state fate factor", specific to the system considered. The range of steady state fate factors obtained for
Preston, Stephen D.; Alexander, Richard B.; Schwarz, Gregory E.; Crawford, Charles G.
2011-01-01
We compared the results of 12 recently calibrated regional SPARROW (SPAtially Referenced Regressions On Watershed attributes) models covering most of the continental United States to evaluate the consistency and regional differences in factors affecting stream nutrient loads. The models - 6 for total nitrogen and 6 for total phosphorus - all provide similar levels of prediction accuracy, but those for major river basins in the eastern half of the country were somewhat more accurate. The models simulate long-term mean annual stream nutrient loads as a function of a wide range of known sources and climatic (precipitation, temperature), landscape (e.g., soils, geology), and aquatic factors affecting nutrient fate and transport. The results confirm the dominant effects of urban and agricultural sources on stream nutrient loads nationally and regionally, but reveal considerable spatial variability in the specific types of sources that control water quality. These include regional differences in the relative importance of different types of urban (municipal and industrial point vs. diffuse urban runoff) and agriculture (crop cultivation vs. animal waste) sources, as well as the effects of atmospheric deposition, mining, and background (e.g., soil phosphorus) sources on stream nutrients. Overall, we found that the SPARROW model results provide a consistent set of information for identifying the major sources and environmental factors affecting nutrient fate and transport in United States watersheds at regional and subregional scales. ?? 2011 American Water Resources Association. This article is a U.S. Government work and is in the public domain in the USA.
Reproducing the Wechsler Intelligence Scale for Children-Fifth Edition: Factor Model Results
Beaujean, A. Alexander
2016-01-01
One of the ways to increase the reproducibility of research is for authors to provide a sufficient description of the data analytic procedures so that others can replicate the results. The publishers of the Wechsler Intelligence Scale for Children-Fifth Edition (WISC-V) do not follow these guidelines when reporting their confirmatory factor…
Directory of Open Access Journals (Sweden)
Thabisile Mpofana
2016-01-01
Full Text Available Early life adversity increases the risk of mental disorders later in life. Chronic early life stress may alter neurotrophic factor gene expression including those for brain derived neurotrophic factor (BDNF and glial cell derived neurotrophic factor (GDNF that are important in neuronal growth, survival, and maintenance. Maternal separation was used in this study to model early life stress. Following unilateral injection of a mild dose of 6-hydroxydopamine (6-OHDA, we measured corticosterone (CORT in the blood and striatum of stressed and nonstressed rats; we also measured DNA methylation and BDNF and GDNF gene expression in the striatum using real time PCR. In the presence of stress, we found that there was increased corticosterone concentration in both blood and striatal tissue. Further to this, we found higher DNA methylation and decreased neurotrophic factor gene expression. 6-OHDA lesion increased neurotrophic factor gene expression in both stressed and nonstressed rats but this increase was higher in the nonstressed rats. Our results suggest that exposure to early postnatal stress increases corticosterone concentration which leads to increased DNA methylation. This effect results in decreased BDNF and GDNF gene expression in the striatum leading to decreased protection against subsequent insults later in life.
Buczkowski, Krzysztof; Basinska, Małgorzata A; Ratajska, Anna; Lewandowska, Katarzyna; Luszkiewicz, Dorota; Sieminska, Alicja
2017-01-27
Tobacco smoking is the single most important modifiable factor in increased morbidity and premature mortality. Numerous factors-including genetics, personality, and environment-affect the development and persistence of tobacco addiction, and knowledge regarding these factors could improve smoking cessation rates. This study compared personality traits between never, former, and current smokers, using the Five-Factor Model of Personality in a country with a turbulent smoking reduction process.: In this cross-sectional study, 909 Polish adults completed the Revised Neuroticism-Extraversion-Openness Personality Inventory. Our results showed that current smokers' scores for extraversion, one of the five global dimensions of personality, were higher relative to never smokers. Neuroticism, openness to experience, agreeableness, and conscientiousness did not differ significantly according to smoking status. Facet analysis, which described each dimension in detail, showed that current smokers' activity and excitement seeking (facets of extraversion) scores were higher relative to those of never and former smokers. In turn, current smokers' dutifulness and deliberation (facets of conscientiousness) scores were lower than those found in former and never smokers. Never smokers scored the highest in self-consciousness (a facet of neuroticism) and compliance (a component of agreeableness). The study conducted among Polish individuals showed variation in personality traits according to their smoking status; however, this variation differed from that reported in countries in which efforts to reduce smoking had begun earlier relative to Poland. Knowledge regarding personality traits could be useful in designing smoking prevention and cessation programs tailored to individuals' needs.
Directory of Open Access Journals (Sweden)
Krzysztof Buczkowski
2017-01-01
Full Text Available Tobacco smoking is the single most important modifiable factor in increased morbidity and premature mortality. Numerous factors—including genetics, personality, and environment—affect the development and persistence of tobacco addiction, and knowledge regarding these factors could improve smoking cessation rates. This study compared personality traits between never, former, and current smokers, using the Five-Factor Model of Personality in a country with a turbulent smoking reduction process.: In this cross-sectional study, 909 Polish adults completed the Revised Neuroticism-Extraversion-Openness Personality Inventory. Our results showed that current smokers’ scores for extraversion, one of the five global dimensions of personality, were higher relative to never smokers. Neuroticism, openness to experience, agreeableness, and conscientiousness did not differ significantly according to smoking status. Facet analysis, which described each dimension in detail, showed that current smokers’ activity and excitement seeking (facets of extraversion scores were higher relative to those of never and former smokers. In turn, current smokers’ dutifulness and deliberation (facets of conscientiousness scores were lower than those found in former and never smokers. Never smokers scored the highest in self-consciousness (a facet of neuroticism and compliance (a component of agreeableness. The study conducted among Polish individuals showed variation in personality traits according to their smoking status; however, this variation differed from that reported in countries in which efforts to reduce smoking had begun earlier relative to Poland. Knowledge regarding personality traits could be useful in designing smoking prevention and cessation programs tailored to individuals’ needs.
Buczkowski, Krzysztof; Basinska, Małgorzata A.; Ratajska, Anna; Lewandowska, Katarzyna; Luszkiewicz, Dorota; Sieminska, Alicja
2017-01-01
Tobacco smoking is the single most important modifiable factor in increased morbidity and premature mortality. Numerous factors—including genetics, personality, and environment—affect the development and persistence of tobacco addiction, and knowledge regarding these factors could improve smoking cessation rates. This study compared personality traits between never, former, and current smokers, using the Five-Factor Model of Personality in a country with a turbulent smoking reduction process.: In this cross-sectional study, 909 Polish adults completed the Revised Neuroticism-Extraversion-Openness Personality Inventory. Our results showed that current smokers’ scores for extraversion, one of the five global dimensions of personality, were higher relative to never smokers. Neuroticism, openness to experience, agreeableness, and conscientiousness did not differ significantly according to smoking status. Facet analysis, which described each dimension in detail, showed that current smokers’ activity and excitement seeking (facets of extraversion) scores were higher relative to those of never and former smokers. In turn, current smokers’ dutifulness and deliberation (facets of conscientiousness) scores were lower than those found in former and never smokers. Never smokers scored the highest in self-consciousness (a facet of neuroticism) and compliance (a component of agreeableness). The study conducted among Polish individuals showed variation in personality traits according to their smoking status; however, this variation differed from that reported in countries in which efforts to reduce smoking had begun earlier relative to Poland. Knowledge regarding personality traits could be useful in designing smoking prevention and cessation programs tailored to individuals’ needs. PMID:28134805
Ibáñez-Sanz, Gemma; Díez-Villanueva, Anna; Alonso, M. Henar; Rodríguez-Moranta, Francisco; Pérez-Gómez, Beatriz; Bustamante, Mariona; Martin, Vicente; Llorca, Javier; Amiano, Pilar; Ardanaz, Eva; Tardón, Adonina; Jiménez-Moleón, Jose J.; Peiró, Rosana; Alguacil, Juan; Navarro, Carmen; Guinó, Elisabet; Binefa, Gemma; Navarro, Pablo Fernández; Espinosa, Anna; Dávila-Batista, Verónica; Molina, Antonio José; Palazuelos, Camilo; Castaño-Vinyals, Gemma; Aragonés, Nuria; Kogevinas, Manolis; Pollán, Marina; Moreno, Victor
2017-01-01
Colorectal cancer (CRC) screening of the average risk population is only indicated according to age. We aim to elaborate a model to stratify the risk of CRC by incorporating environmental data and single nucleotide polymorphisms (SNP). The MCC-Spain case-control study included 1336 CRC cases and 2744 controls. Subjects were interviewed on lifestyle factors, family and medical history. Twenty-one CRC susceptibility SNPs were genotyped. The environmental risk model, which included alcohol consumption, obesity, physical activity, red meat and vegetable consumption, and nonsteroidal anti-inflammatory drug use, contributed to CRC with an average per factor OR of 1.36 (95% CI 1.27 to 1.45). Family history of CRC contributed an OR of 2.25 (95% CI 1.87 to 2.72), and each additional SNP contributed an OR of 1.07 (95% CI 1.04 to 1.10). The risk of subjects with more than 25 risk alleles (5th quintile) was 82% higher (OR 1.82, 95% CI 1.11 to 2.98) than subjects with less than 19 alleles (1st quintile). This risk model, with an AUROC curve of 0.63 (95% CI 0.60 to 0.66), could be useful to stratify individuals. Environmental factors had more weight than the genetic score, which should be considered to encourage patients to achieve a healthier lifestyle. PMID:28233817
Directory of Open Access Journals (Sweden)
Hongling Guo
2014-03-01
Full Text Available Seed production and quality are important factors influencing population regeneration in many seed plants. We used structural equation modeling to investigate how plant and fruit traits interact with each other to influence the fruit crops and seed fates of Pistacia chinensis. From May to September 2009, we sampled 45 fruiting female trees and measured plant traits (height, DBH and crown area, fruit traits (infructescence size, fruit size and the fruit crop of each sampled tree in Jiyuan City of Henan Province, Central China. The fruit crops of P. chinensis were positively correlated with tree height, crown area and infructescence size but not significantly correlated with DBH or fruit size. The fruit crop of an individual tree had no negative direct effect on the infestation of seeds by wasps (Eurytoma plotnikovi. Such a direct effect would be predicted by the predator satiation hypothesis. Tree height and fruit size had a positive direct effect on the seed predation rate, but a significant negative correlation was found between the seed predation rate and the rate of seedlessness. Our results indicate that seedless fruits may serve as a defensive mechanism against insect seed predators. In addition, both seedless and insect-infested fruits had a negative direct effect on seed survival, and DBH, infructescence size and fruit crop had a positive indirect effect on seed survival. However, tree height and fruit size had negative indirect effects on seed survival. In conclusion, we have shown that both plant and fruit traits can strongly influence fruit crops and insect seed predation and subsequently determine the seed quality and population regeneration of P. chinensis.
Synthesizing Regression Results: A Factored Likelihood Method
Wu, Meng-Jia; Becker, Betsy Jane
2013-01-01
Regression methods are widely used by researchers in many fields, yet methods for synthesizing regression results are scarce. This study proposes using a factored likelihood method, originally developed to handle missing data, to appropriately synthesize regression models involving different predictors. This method uses the correlations reported…
Zhang, Yongbin
2015-06-01
Quantitative comparisons were made between the flow factor approach model and the molecular dynamics simulation (MDS) results both of which describe the flow of a molecularly thin fluid film confined between two solid walls. Although these two approaches, respectively, calculate the flow of a confined molecularly thin fluid film by different ways, very good agreements were found between them when the Couette and Poiseuille flows, respectively, calculated from them were compared. It strongly indicates the validity of the flow factor approach model in modeling the flow of a confined molecularly thin fluid film.
DEHAAN, G; DONTJE, B; NIJHOF, W; LOEFFLER, M
1995-01-01
The aim of this study was to determine how stem cell factor (SCF) modifies hemopoietic cell production. First we determined the effects of a prolonged SCP administration on murine hemopoiesis and analyzed the results by a mathematical simulation model of hemopoiesis in order to explain the data. Sub
Multilevel Mixture Factor Models
Varriale, Roberta; Vermunt, Jeroen K.
2012-01-01
Factor analysis is a statistical method for describing the associations among sets of observed variables in terms of a small number of underlying continuous latent variables. Various authors have proposed multilevel extensions of the factor model for the analysis of data sets with a hierarchical structure. These Multilevel Factor Models (MFMs)…
Directory of Open Access Journals (Sweden)
Cristina M. Wood
2015-05-01
Full Text Available Background: Panic disorder (PD is a highly prevalent and disabling mental health problem associated with different factors including perfectionism, stress, physiological anxiety, and anxiety sensitivity regarding physical concerns; however, no studies have analyzed the joint relationship between these factors and PD in a multi-factor model using structural equation modeling. Method: A cross-sectional study was carried out to collect data on these factors and self-reported DSM-IV past-year PD symptoms in a large sample of the general population (N=936. Results: Perceived stress had a significant effect in increasing physiological anxiety, which in turn had an important association with physical concerns. Perfectionism and perceived stress had an indirect relation with past year PD via the mediator role of physiological anxiety and physical concerns. Physical concerns, on one hand, seemed to mediate the impact between perfectionism and PD and, on the other, partially mediated the role between physiological anxiety and PD. Conclusions: Although there is considerable evidence on the association between each of these factors and PD, this model can be considered a broader and productive framework of research on the nature and treatment of PD.
Cone Penetrometer N Factor Determination Testing Results
Energy Technology Data Exchange (ETDEWEB)
Follett, Jordan R.
2014-03-05
This document contains the results of testing activities to determine the empirical 'N Factor' for the cone penetrometer in kaolin clay simulant. The N Factor is used to releate resistance measurements taken with the cone penetrometer to shear strength.
Savory, L A; Griffin, S J; Williams, K M; Prevost, A T; Kinmonth, A-L; Wareham, N J; Simmons, R K
2014-01-01
Aims To describe change in self-reported diet and plasma vitamin C, and to examine associations between change in diet and cardiovascular disease risk factors and modelled 10-year cardiovascular disease risk in the year following diagnosis of Type 2 diabetes. Methods Eight hundred and sixty-seven individuals with screen-detected diabetes underwent assessment of self-reported diet, plasma vitamin C, cardiovascular disease risk factors and modelled cardiovascular disease risk at baseline and 1 year (n = 736) in the ADDITION-Cambridge trial. Multivariable linear regression was used to quantify the association between change in diet and cardiovascular disease risk at 1 year, adjusting for change in physical activity and cardio-protective medication. Results Participants reported significant reductions in energy, fat and sodium intake, and increases in fruit, vegetable and fibre intake over 1 year. The reduction in energy was equivalent to an average-sized chocolate bar; the increase in fruit was equal to one plum per day. There was a small increase in plasma vitamin C levels. Increases in fruit intake and plasma vitamin C were associated with small reductions in anthropometric and metabolic risk factors. Increased vegetable intake was associated with an increase in BMI and waist circumference. Reductions in fat, energy and sodium intake were associated with reduction in HbA1c, waist circumference and total cholesterol/modelled cardiovascular disease risk, respectively. Conclusions Improvements in dietary behaviour in this screen-detected population were associated with small reductions in cardiovascular disease risk, independently of change in cardio-protective medication and physical activity. Dietary change may have a role to play in the reduction of cardiovascular disease risk following diagnosis of diabetes. PMID:24102972
Model Correction Factor Method
DEFF Research Database (Denmark)
Christensen, Claus; Randrup-Thomsen, Søren; Morsing Johannesen, Johannes
1997-01-01
The model correction factor method is proposed as an alternative to traditional polynomial based response surface techniques in structural reliability considering a computationally time consuming limit state procedure as a 'black box'. The class of polynomial functions is replaced by a limit...... statebased on an idealized mechanical model to be adapted to the original limit state by the model correction factor. Reliable approximations are obtained by iterative use of gradient information on the original limit state function analogously to previous response surface approaches. However, the strength...... of the model correction factor method, is that in simpler form not using gradient information on the original limit state function or only using this information once, a drastic reduction of the number of limit state evaluation is obtained together with good approximations on the reliability. Methods...
Directory of Open Access Journals (Sweden)
Kerry N Veth
2011-02-01
Full Text Available The glaucomas comprise a genetically complex group of retinal neuropathies that typically occur late in life and are characterized by progressive pathology of the optic nerve head and degeneration of retinal ganglion cells. In addition to age and family history, other significant risk factors for glaucoma include elevated intraocular pressure (IOP and myopia. The complexity of glaucoma has made it difficult to model in animals, but also challenging to identify responsible genes. We have used zebrafish to identify a genetically complex, recessive mutant that shows risk factors for glaucoma including adult onset severe myopia, elevated IOP, and progressive retinal ganglion cell pathology. Positional cloning and analysis of a non-complementing allele indicated that non-sense mutations in low density lipoprotein receptor-related protein 2 (lrp2 underlie the mutant phenotype. Lrp2, previously named Megalin, functions as an endocytic receptor for a wide-variety of bioactive molecules including Sonic hedgehog, bone morphogenic protein 4, retinol-binding protein, vitamin D-binding protein, and apolipoprotein E, among others. Detailed phenotype analyses indicated that as lrp2 mutant fish age, many individuals--but not all--develop high IOP and severe myopia with obviously enlarged eye globes. This results in retinal stretch and prolonged stress to retinal ganglion cells, which ultimately show signs of pathogenesis. Our studies implicate altered Lrp2-mediated homeostasis as important for myopia and other risk factors for glaucoma in humans and establish a new genetic model for further study of phenotypes associated with this disease.
1993-01-01
Jack is an advanced human factors software package that provides a three dimensional model for predicting how a human will interact with a given system or environment. It can be used for a broad range of computer-aided design applications. Jack was developed by the computer Graphics Research Laboratory of the University of Pennsylvania with assistance from NASA's Johnson Space Center, Ames Research Center and the Army. It is the University's first commercial product. Jack is still used for academic purposes at the University of Pennsylvania. Commercial rights were given to Transom Technologies, Inc.
Pediatric renal transplantation: Results and prognostic factors
Directory of Open Access Journals (Sweden)
Po-Cheng Huang
2013-04-01
Conclusion: For pediatric patients, we found that renal transplantation is now a safe and effective surgical procedure for children with end-stage renal disease. Acute rejection and male gender were identified as prognostic factors for poor graft survival.
Piir, G; Sild, S; Maran, U
2014-01-01
In environmental risk assessment, the bio-concentration factor (BCF) is a widely used parameter in the estimation of the bio-accumulation potential of chemicals. BCF data often have an uneven distribution of classes (bio-accumulative vs. non-bio-accumulative), which could severely bias the classification results towards the prevailing class. The present study focuses on the influence of uneven distribution of the classes in training phase of Random Forest (RF) classification models. Three different training set designs were used and descriptors selected to the models based on the occurrence frequency in RF trees and considering the mechanistic aspects they reflect. Models were compared and their classification performance was analysed, indicating good predictive characteristics (sensitivity = 0.90 and specificity = 0.83) for the balanced set; also imbalanced sets have their strengths in certain application scenarios. The confidence of classifications was assessed with a new schema for the applicability domain that makes use of the RF proximity matrix by analysing the similarity between the predicted compound and the training set of the model. All developed models were made available in the transparent, accessible and reproducible way in QsarDB repository (http://dx.doi.org/10.15152/QDB.116).
Kaymakcalan, Marina D; Xie, Wanling; Albiges, Laurence; North, Scott A; Kollmannsberger, Christian K; Smoragiewicz, Martin; Kroeger, Nils; Wells, J Connor; Rha, Sun-Young; Lee, Jae Lyun; McKay, Rana R; Fay, André P; De Velasco, Guillermo; Heng, Daniel Y C; Choueiri, Toni K
2016-02-01
Vascular endothelial growth factor (VEGF)-targeted therapies are standard treatment for metastatic renal cell carcinoma (mRCC); however, toxicities can lead to drug discontinuation, which can affect patient outcomes. This study was aimed at identifying risk factors for toxicity and constructing the first model to predict toxicity-related treatment discontinuation (TrTD) in mRCC patients treated with VEGF-targeted therapies. The baseline characteristics, treatment outcomes, and toxicity data were collected for 936 mRCC patients receiving first-line VEGF-targeted therapy from the International Metastatic Renal Cell Carcinoma Database Consortium. A competing risk regression model was used to identify risk factors for TrTD, and it accounted for other causes as competing risks. Overall, 198 (23.8%) experienced TrTD. Sunitinib was the most common VEGF-targeted therapy (77%), and it was followed by sorafenib (18.4%). The median time on therapy was 7.1 months for all patients and 4.4 months for patients with TrTD. The most common toxicities leading to TrTD included fatigue, diarrhea, and mucositis. In a multivariate analysis, significant predictors for TrTD were a baseline age ≥60 years, a glomerular filtration rate (GFR) factors to predict the risk of TrTD. In the largest series to date, age, GFR, number of metastatic sites, and baseline sodium level were found to be independent risk factors for TrTD in mRCC patients receiving VEGF-targeted therapy. Based on the number of risk factors present, a model for predicting TrTD was built to be used as a tool for toxicity monitoring in clinical practice. © 2015 American Cancer Society.
Design of financial results on the basis of factor analysis
Directory of Open Access Journals (Sweden)
V. M. Sidorov
2016-01-01
Full Text Available Approaches are presented in the article, qualificatory the design of financial results on the basis of factor analysis. Connection marks between development of enterprises and scientific and technical progress. It is shown that potential of enterprises can be based on the design of financial results. Actuality of this direction of research marks on a background the entered approvals against Russia. A control role is indicated at the effective use of resources. It is well-proven that a key moment in forming of profit of enterprise is a design of financial results. A factor analysis is reasonable at the estimation of activity of organization, which exposed an application of this determined model domain. is sent to capital augmentation. The role of the financial system and separate elements is shown in to financially-economic activity. Connection is set between a design and structure of the investigated object. A design cannot come true without determination of structure of the investigated object, because a structure characterizes steady connections between elements. The components of elements are able in totality to counteract to external influences. For expansion of the system to distinguish the most meaningful factors. To distinguish integrating connections from appropriate. Distinguished, that factors due to co-operating with each other can create a synergistically or extinguishing effect or neutralize each other. Factors will organize or will disorganize work of organization. The design of objects is built on the certain terms, and separate parties of object are examined at abandonment from the less meaningful elements of the system. The role of empiric and theoretical level of research in the design of activity of organization is shown. An author suggested to use the determined model for determination of functional connections between a resulting index and factor signs. Exposed an application of this determined model domain.
Hydraulic fracture model comparison study: Complete results
Energy Technology Data Exchange (ETDEWEB)
Warpinski, N.R. [Sandia National Labs., Albuquerque, NM (United States); Abou-Sayed, I.S. [Mobil Exploration and Production Services (United States); Moschovidis, Z. [Amoco Production Co. (US); Parker, C. [CONOCO (US)
1993-02-01
Large quantities of natural gas exist in low permeability reservoirs throughout the US. Characteristics of these reservoirs, however, make production difficult and often economic and stimulation is required. Because of the diversity of application, hydraulic fracture design models must be able to account for widely varying rock properties, reservoir properties, in situ stresses, fracturing fluids, and proppant loads. As a result, fracture simulation has emerged as a highly complex endeavor that must be able to describe many different physical processes. The objective of this study was to develop a comparative study of hydraulic-fracture simulators in order to provide stimulation engineers with the necessary information to make rational decisions on the type of models most suited for their needs. This report compares the fracture modeling results of twelve different simulators, some of them run in different modes for eight separate design cases. Comparisons of length, width, height, net pressure, maximum width at the wellbore, average width at the wellbore, and average width in the fracture have been made, both for the final geometry and as a function of time. For the models in this study, differences in fracture length, height and width are often greater than a factor of two. In addition, several comparisons of the same model with different options show a large variability in model output depending upon the options chosen. Two comparisons were made of the same model run by different companies; in both cases the agreement was good. 41 refs., 54 figs., 83 tabs.
Shell model and spectroscopic factors
Energy Technology Data Exchange (ETDEWEB)
Poves, P. [Madrid Univ. Autonoma and IFT, UAM/CSIC, E-28049 (Spain)
2007-07-01
In these lectures, I introduce the notion of spectroscopic factor in the shell model context. A brief review is given of the present status of the large scale applications of the Interacting Shell Model. The spectroscopic factors and the spectroscopic strength are discussed for nuclei in the vicinity of magic closures and for deformed nuclei. (author)
The cyclical component factor model
DEFF Research Database (Denmark)
Dahl, Christian Møller; Hansen, Henrik; Smidt, John
Forecasting using factor models based on large data sets have received ample attention due to the models' ability to increase forecast accuracy with respect to a range of key macroeconomic variables in the US and the UK. However, forecasts based on such factor models do not uniformly outperform...... the simple autoregressive model when using data from other countries. In this paper we propose to estimate the factors based on the pure cyclical components of the series entering the large data set. Monte Carlo evidence and an empirical illustration using Danish data shows that this procedure can indeed...
An innovation resistance factor model
Directory of Open Access Journals (Sweden)
Siti Salwa Mohd Ishak
2016-09-01
Full Text Available The process and implementation strategy of information technology in construction is generally considered through the limiting prism of theoretical contexts generated from innovation diffusion and acceptance. This research argues that more attention should be given to understanding the positive effects of resistance. The study develops a theoretical framing for the Integrated Resistance Factor Model (IRFM. The framing uses a combination of diffusion of innovation theory, technology acceptance model and social network perspective. The model is tested to identify the most significant resistance factors using Partial Least Square (PLS technique. All constructs proposed in the model are found to be significant, valid and consistent with the theoretical framework. IRFM is shown to be an effective and appropriate model of user resistance factors. The most critical factors to influence technology resistance in the online project information management system (OPIMS context are: support from leaders and peers, complexity of the technology, compatibility with key work practices; and pre-trial of the technology before it is actually deployed. The study provides a new model for further research in technology innovation specific to the construction industry.
McGurk, B. J.; Painter, T. H.
2014-12-01
Deterministic snow accumulation and ablation simulation models are widely used by runoff managers throughout the world to predict runoff quantities and timing. Model fitting is typically based on matching modeled runoff volumes and timing with observed flow time series at a few points in the basin. In recent decades, sparse networks of point measurements of the mountain snowpacks have been available to compare with modeled snowpack, but the comparability of results from a snow sensor or course to model polygons of 5 to 50 sq. km is suspect. However, snowpack extent, depth, and derived snow water equivalent have been produced by the NASA/JPL Airborne Snow Observatory (ASO) mission for spring of 20013 and 2014 in the Tuolumne River basin above Hetch Hetchy Reservoir. These high-resolution snowpack data have exposed the weakness in a model calibration based on runoff alone. The U.S. Geological Survey's Precipitation Runoff Modeling System (PRMS) calibration that was based on 30-years of inflow to Hetch Hetchy produces reasonable inflow results, but modeled spatial snowpack location and water quantity diverged significantly from the weekly measurements made by ASO during the two ablation seasons. The reason is that the PRMS model has many flow paths, storages, and water transfer equations, and a calibrated outflow time series can be right for many wrong reasons. The addition of a detailed knowledge of snow extent and water content constrains the model so that it is a better representation of the actual watershed hydrology. The mechanics of recalibrating PRMS to the ASO measurements will be described, and comparisons in observed versus modeled flow for both a small subbasin and the entire Hetch Hetchy basin will be shown. The recalibrated model provided a bitter fit to the snowmelt recession, a key factor for water managers as they balance declining inflows with demand for power generation and ecosystem releases during the final months of snow melt runoff.
Bayesian Estimation of Categorical Dynamic Factor Models
Zhang, Zhiyong; Nesselroade, John R.
2007-01-01
Dynamic factor models have been used to analyze continuous time series behavioral data. We extend 2 main dynamic factor model variations--the direct autoregressive factor score (DAFS) model and the white noise factor score (WNFS) model--to categorical DAFS and WNFS models in the framework of the underlying variable method and illustrate them with…
Three kinds of extraneous factors in Dixon resultants
Institute of Scientific and Technical Information of China (English)
ZHAO ShiZhong; FU HongGuang
2009-01-01
Dixon resultant is a basic elimination method which has been used widely in the high technology fields of automatic control,robotics,etc.But how to remove extraneous factors in Dixon resultants has been a very difficult problem.In this paper,we discover some extraneous factors by expressing the Dixon resultant in a linear combination of original polynomial system.Furthermore,it has been proved that the factors mentioned above include three parts which come from Dixon derived polynomials,Dixon matrix and the resulting resultant expression by substituting Dixon derived polynomials respectively.
Huntzinger, D. N.; Schwalm, C. R.; Michalak, A. M.; Wei, Y.; Cook, R. B.; Schaefer, K. M.; Jacobson, A. R.; Arain, M. A.; Ciais, P.; Fisher, J. B.; Hayes, D. J.; Huang, M.; Huang, S.; Ito, A.; Jain, A.; Lei, H.; Lu, C.; Maignan, F.; Mao, J.; Parazoo, N.; Peng, S.; Peng, C.; Poulter, B.; Ricciuto, D. M.; Shi, X.; Tian, H.; Zeng, N.; Zhao, F.; Zhu, Q.; Wang, W.
2014-12-01
Predictions of future climate depend strongly on trends in net uptake or release of carbon by the land biosphere. However, model estimates of the strength of the net global land sink during the Industrial Era vary widely. Here we evaluate results from an ensemble of uncoupled models taken from the Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP) and forced by the same input fields. When compared to estimates inferred from atmospheric CO2 observations (i.e., fossil fuel emission + net land use change - atmospheric increase - ocean uptake), MsTMIP models estimate, on average, a stronger global net land uptake of carbon (e.g., -0.3 to 8.7 Pg C/yr from 2000 to 2010, where a negative flux represents a net release to the atmosphere). Some models consistently show the land surface as a net source of carbon to the atmosphere, which is inconsistent with the other terms in the global anthropogenic CO2 budget. In addition, regional differences in land carbon exchange are compared across models and to estimates derived from atmospheric inversions and inventory based approaches. Using the semi-factorial simulations of the MsTMIP activity, we examine how model estimates of the cumulative global net land sink diverge over the period 1900 to 2010, and the degree to which model sensitivity to forcing factors contribute to this divergence. We link differences in estimates of the cumulative land sink back to each model's sensitivity to climate variability, CO2 fertilization, nitrogen limitation, and net land-use change. Throughout the 110-year time period, the strength of carbon uptake in most models appears to be strongly sensitive to atmospheric CO2 concentrations (CO2 fertilization effect). The strength of this relationship, however, varies across models depending on model structure (e.g., stronger CO2 fertilization effect in models without an interactive nitrogen cycle with N limitations) and across decades (e.g., strong sensitivity of net flux to
A hierarchical model for ordinal matrix factorization
DEFF Research Database (Denmark)
Paquet, Ulrich; Thomson, Blaise; Winther, Ole
2012-01-01
their ratings for other movies. The Netflix data set is used for evaluation, which consists of around 100 million ratings. Using root mean-squared error (RMSE) as an evaluation metric, results show that the suggested model outperforms alternative factorization techniques. Results also show how Gibbs sampling...
Exploring Technostress: Results of a Large Sample Factor Analysis
Steponas Jonušauskas; Agota Giedre Raisiene
2016-01-01
With reference to the results of a large sample factor analysis, the article aims to propose the frame examining technostress in a population. The survey and principal component analysis of the sample consisting of 1013 individuals who use ICT in their everyday work was implemented in the research. 13 factors combine 68 questions and explain 59.13 per cent of the answers dispersion. Based on the factor analysis, questionnaire was reframed and prepared to reasonably analyze the respondents’ an...
Deksissa, Zewdie Mulissa; Tesfamichael, Fessahaye Alemseged; Ferede, Henok Assefa
2015-10-29
Cervical cancer is the 2nd most frequent and top killer cancer among women in Ethiopia. Prevalence and factors associated with visual inspection with acetic acid (VIA) positive result is not studied yet at the study area. A cross-sectional study was conducted at Jimma model clinic of Family Guidance Association of Ethiopia, from September 11, 2013 to October 11, 2013. Pertinent data of 334 screened clients were transferred to Epidata version3.1 using checklist, double data entry verification done and exported to SPSS version16.0. After cleaning the data, descriptive analysis was done and logistic regression model employed to identify predictors of VIA positive result. Statistical significance was declared at P result. Initiation of sexual intercourse earlier than 16 years was found to be an independent predictor increasing the risk of VIA positive by 2.2 times as compared to clients who started at the age of 16 or more years (AOR [95% CI] = 2.2 [1.1, 4.3]). Early initiation of sexual intercourse was an independent predictor of VIA positive result in this study. Thus, any cervical cancer prevention and control effort at the study area should address the problem of early initiation of sexual intercourse.
Interpreting Results from the Multinomial Logit Model
DEFF Research Database (Denmark)
Wulff, Jesper
2015-01-01
This article provides guidelines and illustrates practical steps necessary for an analysis of results from the multinomial logit model (MLM). The MLM is a popular model in the strategy literature because it allows researchers to examine strategic choices with multiple outcomes. However, there see...
The Infinite Hierarchical Factor Regression Model
Rai, Piyush
2009-01-01
We propose a nonparametric Bayesian factor regression model that accounts for uncertainty in the number of factors, and the relationship between factors. To accomplish this, we propose a sparse variant of the Indian Buffet Process and couple this with a hierarchical model over factors, based on Kingman's coalescent. We apply this model to two problems (factor analysis and factor regression) in gene-expression data analysis.
Performance results of HESP physical model
Chanumolu, Anantha; Thirupathi, Sivarani; Jones, Damien; Giridhar, Sunetra; Grobler, Deon; Jakobsson, Robert
2017-02-01
As a continuation to the published work on model based calibration technique with HESP(Hanle Echelle Spectrograph) as a case study, in this paper we present the performance results of the technique. We also describe how the open parameters were chosen in the model for optimization, the glass data accuracy and handling the discrepancies. It is observed through simulations that the discrepancies in glass data can be identified but not quantifiable. So having an accurate glass data is important which is possible to obtain from the glass manufacturers. The model's performance in various aspects is presented using the ThAr calibration frames from HESP during its pre-shipment tests. Accuracy of model predictions and its wave length calibration comparison with conventional empirical fitting, the behaviour of open parameters in optimization, model's ability to track instrumental drifts in the spectrum and the double fibres performance were discussed. It is observed that the optimized model is able to predict to a high accuracy the drifts in the spectrum from environmental fluctuations. It is also observed that the pattern in the spectral drifts across the 2D spectrum which vary from image to image is predictable with the optimized model. We will also discuss the possible science cases where the model can contribute.
A Two-Factor Model of Temperament
Evans, David E.; Rothbart, Mary K.
2009-01-01
The higher order structure of temperament was examined in two studies using the Adult Temperament Questionnaire. Because previous research showed robust levels of convergence between Rothbart’s constructs of temperament and the Big Five factors, we hypothesized a higher order two-factor model of temperament based on Digman’s higher order two-factor model of personality traits derived from factor analysis of the Big Five factors. Study 1 included 258 undergraduates. Digman’s model did not fit ...
Exploring Technostress: Results of a Large Sample Factor Analysis
Directory of Open Access Journals (Sweden)
Steponas Jonušauskas
2016-06-01
Full Text Available With reference to the results of a large sample factor analysis, the article aims to propose the frame examining technostress in a population. The survey and principal component analysis of the sample consisting of 1013 individuals who use ICT in their everyday work was implemented in the research. 13 factors combine 68 questions and explain 59.13 per cent of the answers dispersion. Based on the factor analysis, questionnaire was reframed and prepared to reasonably analyze the respondents’ answers, revealing technostress causes and consequences as well as technostress prevalence in the population in a statistically validated pattern. A key elements of technostress based on factor analysis can serve for the construction of technostress measurement scales in further research.
Modeling Malaysia's Energy System: Some Preliminary Results
Directory of Open Access Journals (Sweden)
Ahmad M. Yusof
2011-01-01
Full Text Available Problem statement: The current dynamic and fragile world energy environment necessitates the development of new energy model that solely caters to analyze Malaysias energy scenarios. Approach: The model is a network flow model that traces the flow of energy carriers from its sources (import and mining through some conversion and transformation processes for the production of energy products to final destinations (energy demand sectors. The integration to the economic sectors is done exogeneously by specifying the annual sectoral energy demand levels. The model in turn optimizes the energy variables for a specified objective function to meet those demands. Results: By minimizing the inter temporal petroleum product imports for the crude oil system the annual extraction level of Tapis blend is projected at 579600 barrels per day. The aggregate demand for petroleum products is projected to grow at 2.1% year-1 while motor gasoline and diesel constitute 42 and 38% of the petroleum products demands mix respectively over the 5 year planning period. Petroleum products import is expected to grow at 6.0% year-1. Conclusion: The preliminary results indicate that the model performs as expected. Thus other types of energy carriers such as natural gas, coal and biomass will be added to the energy system for the overall development of Malaysia energy model.
A physiological production model for cacao : results of model simulations
Zuidema, P.A.; Leffelaar, P.A.
2002-01-01
CASE2 is a physiological model for cocoa (Theobroma cacao L.) growth and yield. This report introduces the CAcao Simulation Engine for water-limited production in a non-technical way and presents simulation results obtained with the model.
A physiological production model for cacao : results of model simulations
Zuidema, P.A.; Leffelaar, P.A.
2002-01-01
CASE2 is a physiological model for cocoa (Theobroma cacao L.) growth and yield. This report introduces the CAcao Simulation Engine for water-limited production in a non-technical way and presents simulation results obtained with the model.
Modelling rainfall erosion resulting from climate change
Kinnell, Peter
2016-04-01
It is well known that soil erosion leads to agricultural productivity decline and contributes to water quality decline. The current widely used models for determining soil erosion for management purposes in agriculture focus on long term (~20 years) average annual soil loss and are not well suited to determining variations that occur over short timespans and as a result of climate change. Soil loss resulting from rainfall erosion is directly dependent on the product of runoff and sediment concentration both of which are likely to be influenced by climate change. This presentation demonstrates the capacity of models like the USLE, USLE-M and WEPP to predict variations in runoff and erosion associated with rainfall events eroding bare fallow plots in the USA with a view to modelling rainfall erosion in areas subject to climate change.
Simulation Modeling of Radio Direction Finding Results
Directory of Open Access Journals (Sweden)
K. Pelikan
1994-12-01
Full Text Available It is sometimes difficult to determine analytically error probabilities of direction finding results for evaluating algorithms of practical interest. Probalistic simulation models are described in this paper that can be to study error performance of new direction finding systems or to geographical modifications of existing configurations.
Robust and Sparse Factor Modelling
DEFF Research Database (Denmark)
Croux, Christophe; Exterkate, Peter
Factor construction methods are widely used to summarize a large panel of variables by means of a relatively small number of representative factors. We propose a novel factor construction procedure that enjoys the properties of robustness to outliers and of sparsity; that is, having relatively few...... nonzero factor loadings. Compared to the traditional factor construction method, we find that this procedure leads to a favorable forecasting performance in the presence of outliers and to better interpretable factors. We investigate the performance of the method in a Monte Carlo experiment...
PENGUJIAN FAMA-FRENCH THREE-FACTOR MODEL DI INDONESIA
Directory of Open Access Journals (Sweden)
Damar Hardianto
2017-03-01
Full Text Available This study empirically examined the Fama-French three factor model of stock returnsfor Indonesia over the period 2000-2004. We found evidence for pervasive market, size, andbook-to-market factors in Indonesian stock returns. We found that cross-sectional mean returnswere explained by exposures to these three factors, and not by the market factor alone. Theempirical results were reasonably consistent with the Fama-French three factor model.
Mackey, Jon; Sehirlioglu, Alp; Dynys, Fred
2014-01-01
A set of convenient thermoelectric device solutions have been derived in order to capture a number of factors which are previously only resolved with numerical techniques. The concise conversion efficiency equations derived from governing equations provide intuitive and straight-forward design guidelines. These guidelines allow for better device design without requiring detailed numerical modeling. The analytical modeling accounts for factors such as i) variable temperature boundary conditions, ii) lateral heat transfer, iii) temperature variable material properties, and iv) transient operation. New dimensionless parameters, similar to the figure of merit, are introduced including the device design factor, fin factor, thermal diffusivity factor, and inductance factor. These new device factors allow for the straight-forward description of phenomenon generally only captured with numerical work otherwise. As an example a device design factor of 0.38, which accounts for thermal resistance of the hot and cold shoes, can be used to calculate a conversion efficiency of 2.28 while the ideal conversion efficiency based on figure of merit alone would be 6.15. Likewise an ideal couple with efficiency of 6.15 will be reduced to 5.33 when lateral heat is accounted for with a fin factor of 1.0.
Shape Factor Modeling and Simulation
2016-06-01
10 3. Shape Factor Distributions for Natural Fragments 12 3.1 Platonic Solids and Uniform Viewing from All Viewpoints 12 3.2 Natural Fragments from...12 Fig. 9 The 5 Platonic solids. ............................................................. 12 Fig. 10 Mean shape factor of...of the 5 Platonic solids............................................ 13 Table 3 Sequence of viewing angles in Icosahedron Gage
Online cognition: factors facilitating reliable online neuropsychological test results.
Feenstra, Heleen E M; Vermeulen, Ivar E; Murre, Jaap M J; Schagen, Sanne B
2017-01-01
Online neuropsychological test batteries could allow for large-scale cognitive data collection in clinical studies. However, the few online neuropsychological test batteries that are currently available often still require supervision or lack proper psychometric evaluation. In this paper, we have outlined prerequisites for proper development and use of online neuropsychological tests, with the focus on reliable measurement of cognitive function in an unmonitored setting. First, we identified several technical, contextual, and psychological factors that should be taken into account in order to facilitate reliable test results of online tests in the unmonitored setting. Second, we outlined a methodology of quality assurance needed in order to obtain reliable cognitive data in the long run. Based on factors that distinguish the online unmonitored test setting from the traditional face-to-face setting, we provide a set of basic requirements and suggestions for optimal development and use of unmonitored online neuropsychological tests, including suggestions on acquiring reliability, validity, and norm scores. When properly addressing factors that could hamper reliable test results during development and use, online neuropsychological tests could aid large-scale data collection for clinical studies in the future. Investment in both proper development of online neuropsychological test platforms and the performance of accompanying psychometric studies is currently required.
Skewed factor models using selection mechanisms
Kim, Hyoung-Moon
2015-12-21
Traditional factor models explicitly or implicitly assume that the factors follow a multivariate normal distribution; that is, only moments up to order two are involved. However, it may happen in real data problems that the first two moments cannot explain the factors. Based on this motivation, here we devise three new skewed factor models, the skew-normal, the skew-tt, and the generalized skew-normal factor models depending on a selection mechanism on the factors. The ECME algorithms are adopted to estimate related parameters for statistical inference. Monte Carlo simulations validate our new models and we demonstrate the need for skewed factor models using the classic open/closed book exam scores dataset.
Development of the Reasonable Accommodation Factor Survey: Results and Implications
Dong, Shengli; MacDonald-Wilson, Kim L.; Fabian, Ellen
2010-01-01
The purpose of this study was (a) to explore the latent factors in the "Reasonable Accommodation Factor Survey" (RAFS) instrument and (b) to compare scores on the latent factors of the RAFS by participant's role. Eight latent factors were identified through an exploratory factor analysis with orthogonal rotation. The reliability tests…
Modeling Ability Differentiation in the Second-Order Factor Model
Molenaar, Dylan; Dolan, Conor V.; van der Maas, Han L. J.
2011-01-01
In this article we present factor models to test for ability differentiation. Ability differentiation predicts that the size of IQ subtest correlations decreases as a function of the general intelligence factor. In the Schmid-Leiman decomposition of the second-order factor model, we model differentiation by introducing heteroscedastic residuals,…
Modeling ability differentiation in the second-order factor model
Molenaar, D.; Dolan, C.V.; van der Maas, H.L.J.
2011-01-01
In this article we present factor models to test for ability differentiation. Ability differentiation predicts that the size of IQ subtest correlations decreases as a function of the general intelligence factor. In the Schmid-Leiman decomposition of the second-order factor model, we model
The Danish national passenger model – Model specification and results
DEFF Research Database (Denmark)
Rich, Jeppe; Hansen, Christian Overgaard
2016-01-01
The paper describes the structure of the new Danish National Passenger model and provides on this basis a general discussion of large-scale model design, cost-damping and model validation. The paper aims at providing three main contributions to the existing literature. Firstly, at the general level......, the paper provides a description of a large-scale forecast model with a discussion of the linkage between population synthesis, demand and assignment. Secondly, the paper gives specific attention to model specification and in particular choice of functional form and cost-damping. Specifically we suggest...... a family of logarithmic spline functions and illustrate how it is applied in the model. Thirdly and finally, we evaluate model sensitivity and performance by evaluating the distance distribution and elasticities. In the paper we present results where the spline-function is compared with more traditional...
Dynamic Factor Models for the Volatility Surface
DEFF Research Database (Denmark)
van der Wel, Michel; Ozturk, Sait R.; Dijk, Dick van
The implied volatility surface is the collection of volatilities implied by option contracts for different strike prices and time-to-maturity. We study factor models to capture the dynamics of this three-dimensional implied volatility surface. Three model types are considered to examine desirable...... features for representing the surface and its dynamics: a general dynamic factor model, restricted factor models designed to capture the key features of the surface along the moneyness and maturity dimensions, and in-between spline-based methods. Key findings are that: (i) the restricted and spline......-based models are both rejected against the general dynamic factor model, (ii) the factors driving the surface are highly persistent, (iii) for the restricted models option Delta is preferred over the more often used strike relative to spot price as measure for moneyness....
CMS standard model Higgs boson results
Directory of Open Access Journals (Sweden)
Garcia-Abia Pablo
2013-11-01
Full Text Available In July 2012 CMS announced the discovery of a new boson with properties resembling those of the long-sought Higgs boson. The analysis of the proton-proton collision data recorded by the CMS detector at the LHC, corresponding to integrated luminosities of 5.1 fb−1 at √s = 7 TeV and 19.6 fb−1 at √s = 8 TeV, confirm the Higgs-like nature of the new boson, with a signal strength associated with vector bosons and fermions consistent with the expectations for a standard model (SM Higgs boson, and spin-parity clearly favouring the scalar nature of the new boson. In this note I review the updated results of the CMS experiment.
Correlations of MMPI factor scales with measures of the five factor model of personality.
Costa, P T; Busch, C M; Zonderman, A B; McCrae, R R
1986-01-01
Two recent item factor analyses of the Minnesota Multiphasic Personality Inventory (MMPI) classified the resulting factors according to a conceptual scheme offered by Norman's (1963) five factor model. The present article empirically evaluates those classifications by correlating MMPI factor scales with self-report and peer rating measures of the five factor model in a sample of 153 adult men and women. Both sets of predictions were generally supported, although MMPI factors derived in a normal sample showed closer correspondences with the five normal personality dimensions. MMPI factor scales were also correlated with 18 scales measuring specific traits within the broader domains of Neuroticism, Extraversion, and Openness. The nine Costa, Zonderman, McCrae, and Williams (1985) MMPI factor scales appear to give useful global assessments of four of the five factors; other instruments are needed to provide detailed information on more specific aspects of normal personality. The use of the five factor model in routine clinical assessment is discussed.
Cardinality constrained portfolio selection via factor models
Monge, Juan Francisco
2017-01-01
In this paper we propose and discuss different 0-1 linear models in order to solve the cardinality constrained portfolio problem by using factor models. Factor models are used to build portfolios to track indexes, together with other objectives, also need a smaller number of parameters to estimate than the classical Markowitz model. The addition of the cardinality constraints limits the number of securities in the portfolio. Restricting the number of securities in the portfolio allows us to o...
Space Station crew safety - Human factors model
Cohen, M. M.; Junge, M. K.
1984-01-01
A model of the various human factors issues and interactions that might affect crew safety is developed. The first step addressed systematically the central question: How is this Space Station different from all other spacecraft? A wide range of possible issue was identified and researched. Five major topics of human factors issues that interacted with crew safety resulted: Protocols, Critical Habitability, Work Related Issues, Crew Incapacitation and Personal Choice. Second, an interaction model was developed that would show some degree of cause and effect between objective environmental or operational conditions and the creation of potential safety hazards. The intermediary steps between these two extremes of causality were the effects on human performance and the results of degraded performance. The model contains three milestones: stressor, human performance (degraded) and safety hazard threshold. Between these milestones are two countermeasure intervention points. The first opportunity for intervention is the countermeasure against stress. If this countermeasure fails, performance degrades. The second opportunity for intervention is the countermeasure against error. If this second countermeasure fails, the threshold of a potential safety hazard may be crossed.
Factors associated with results and conclusions of trials of thiazolidinediones.
Directory of Open Access Journals (Sweden)
Gail Rattinger
Full Text Available BACKGROUND: When a sponsor funds a study of two competing drugs in a head-to-head comparison, the results and conclusions are likely to favor the sponsor's drug. Thiazolidinediones, oral medications used for the treatment of type 2 diabetes, are one of the most costly choices of oral anti-diabetic medications, yet they do not demonstrate clinically relevant differences in achieving lower glycosylated hemoglobin levels compared to other oral antidiabetic drugs. Our aim is to examine associations between research funding source, study design characteristics aimed at reducing bias, and other factors with the results and conclusions of randomized controlled trials (RCTs of thiazolidinediones compared to other oral hypoglycemic agents. METHODS AND FINDINGS: This is a cross-sectional study of 61 published RCTs comparing a thiazolidinedione (glitazone to another anti-diabetic drug or placebo for treatment of type 2 diabetes. Data on study design characteristics, funding source, author's financial ties, results for primary outcomes, and author conclusions were extracted. Univariate logistic regression identified associations between independent variables and results and conclusions that favored the glitazone. Of the RCTs, 59% (36/61 were funded by industry, 39% (24/61 did not disclose any funding. Common study design weaknesses included inadequate blinding and lack of concealment of allocation. Trials that reported favorable glycemic control results for the glitazone were more likely to have adequate blinding (OR (95% CI = 5.42 (1.46, 21.19, p = 0.008 and have a corresponding author with financial ties to the glitazone manufacturer (OR (95% CI = 4.12 (1.05, 19.53; p = 0.04. Trials with conclusions favoring the glitazone were less likely to be funded by a comparator drug company than a glitazone company (OR (95% CI = 0.026 (0, 0.40, p = 0.003 and less likely to be published in journals with higher impact factors (OR (95% CI = 0.79 (0.62, 0.97, p = 0
Modeling Malaysia's Energy System: Some Preliminary Results
Ahmad M. Yusof
2011-01-01
Problem statement: The current dynamic and fragile world energy environment necessitates the development of new energy model that solely caters to analyze Malaysias energy scenarios. Approach: The model is a network flow model that traces the flow of energy carriers from its sources (import and mining) through some conversion and transformation processes for the production of energy products to final destinations (energy demand sectors). The integration to the economic sectors is done exogene...
Engineering Glass Passivation Layers -Model Results
Energy Technology Data Exchange (ETDEWEB)
Skorski, Daniel C.; Ryan, Joseph V.; Strachan, Denis M.; Lepry, William C.
2011-08-08
The immobilization of radioactive waste into glass waste forms is a baseline process of nuclear waste management not only in the United States, but worldwide. The rate of radionuclide release from these glasses is a critical measure of the quality of the waste form. Over long-term tests and using extrapolations of ancient analogues, it has been shown that well designed glasses exhibit a dissolution rate that quickly decreases to a slow residual rate for the lifetime of the glass. The mechanistic cause of this decreased corrosion rate is a subject of debate, with one of the major theories suggesting that the decrease is caused by the formation of corrosion products in such a manner as to present a diffusion barrier on the surface of the glass. Although there is much evidence of this type of mechanism, there has been no attempt to engineer the effect to maximize the passivating qualities of the corrosion products. This study represents the first attempt to engineer the creation of passivating phases on the surface of glasses. Our approach utilizes interactions between the dissolving glass and elements from the disposal environment to create impermeable capping layers. By drawing from other corrosion studies in areas where passivation layers have been successfully engineered to protect the bulk material, we present here a report on mineral phases that are likely have a morphological tendency to encrust the surface of the glass. Our modeling has focused on using the AFCI glass system in a carbonate, sulfate, and phosphate rich environment. We evaluate the minerals predicted to form to determine the likelihood of the formation of a protective layer on the surface of the glass. We have also modeled individual ions in solutions vs. pH and the addition of aluminum and silicon. These results allow us to understand the pH and ion concentration dependence of mineral formation. We have determined that iron minerals are likely to form a complete incrustation layer and we plan
Study on neural network model for calculating subsidence factor
Institute of Scientific and Technical Information of China (English)
GUO Wen-bing; ZHANG Jie
2007-01-01
The major factors influencing subsidence factor were comprehensively analyzed. Then the artificial neural network model for calculating subsidence factor was set up with the theory of artificial neural network (ANN). A large amount of data from observation stations in China was collected and used as learning and training samples to train and test the artificial neural network model. The calculated results of the ANN model and the observed values were compared and analyzed in this paper. The results demonstrate that many factors can be considered in this model and the result is more precise and closer to observed values to calculate the subsidence factor by the ANN model. It can satisfy the need of engineering.
Comparison of Transcription Factor Binding Site Models
Bhuyan, Sharifulislam
2012-05-01
Modeling of transcription factor binding sites (TFBSs) and TFBS prediction on genomic sequences are important steps to elucidate transcription regulatory mechanism. Dependency of transcription regulation on a great number of factors such as chemical specificity, molecular structure, genomic and epigenetic characteristics, long distance interaction, makes this a challenging problem. Different experimental procedures generate evidence that DNA-binding domains of transcription factors show considerable DNA sequence specificity. Probabilistic modeling of TFBSs has been moderately successful in identifying patterns from a family of sequences. In this study, we compare performances of different probabilistic models and try to estimate their efficacy over experimental TFBSs data. We build a pipeline to calculate sensitivity and specificity from aligned TFBS sequences for several probabilistic models, such as Markov chains, hidden Markov models, Bayesian networks. Our work, containing relevant statistics and evaluation for the models, can help researchers to choose the most appropriate model for the problem at hand.
Quantitative magnetospheric models: results and perspectives.
Kuznetsova, M.; Hesse, M.; Gombosi, T.; Csem Team
Global magnetospheric models are indispensable tool that allow multi-point measurements to be put into global context Significant progress is achieved in global MHD modeling of magnetosphere structure and dynamics Medium resolution simulations confirm general topological pictures suggested by Dungey State of the art global models with adaptive grids allow performing simulations with highly resolved magnetopause and magnetotail current sheet Advanced high-resolution models are capable to reproduced transient phenomena such as FTEs associated with formation of flux ropes or plasma bubbles embedded into magnetopause and demonstrate generation of vortices at magnetospheric flanks On the other hand there is still controversy about the global state of the magnetosphere predicted by MHD models to the point of questioning the length of the magnetotail and the location of the reconnection sites within it For example for steady southwards IMF driving condition resistive MHD simulations produce steady configuration with almost stationary near-earth neutral line While there are plenty of observational evidences of periodic loading unloading cycle during long periods of southward IMF Successes and challenges in global modeling of magnetispheric dynamics will be addessed One of the major challenges is to quantify the interaction between large-scale global magnetospheric dynamics and microphysical processes in diffusion regions near reconnection sites Possible solutions to controversies will be discussed
System Identification by Dynamic Factor Models
C. Heij (Christiaan); W. Scherrer; M. Destler
1996-01-01
textabstractThis paper concerns the modelling of stochastic processes by means of dynamic factor models. In such models the observed process is decomposed into a structured part called the latent process, and a remainder that is called noise. The observed variables are treated in a symmetric way, so
Value of the distant future: Model-independent results
Katz, Yuri A.
2017-01-01
This paper shows that the model-independent account of correlations in an interest rate process or a log-consumption growth process leads to declining long-term tails of discount curves. Under the assumption of an exponentially decaying memory in fluctuations of risk-free real interest rates, I derive the analytical expression for an apt value of the long run discount factor and provide a detailed comparison of the obtained result with the outcome of the benchmark risk-free interest rate models. Utilizing the standard consumption-based model with an isoelastic power utility of the representative economic agent, I derive the non-Markovian generalization of the Ramsey discounting formula. Obtained analytical results allowing simple calibration, may augment the rigorous cost-benefit and regulatory impact analysis of long-term environmental and infrastructure projects.
Model correction factor method for system analysis
DEFF Research Database (Denmark)
Ditlevsen, Ove Dalager; Johannesen, Johannes M.
2000-01-01
The Model Correction Factor Method is an intelligent response surface method based on simplifiedmodeling. MCFM is aimed for reliability analysis in case of a limit state defined by an elaborate model. Herein it isdemonstrated that the method is applicable for elaborate limit state surfaces on which...... severallocally most central points exist without there being a simple geometric definition of the corresponding failuremodes such as is the case for collapse mechanisms in rigid plastic hinge models for frame structures. Taking as simplifiedidealized model a model of similarity with the elaborate model...... surface than existing in the idealized model....
Personalized Predictive Modeling and Risk Factor Identification using Patient Similarity.
Ng, Kenney; Sun, Jimeng; Hu, Jianying; Wang, Fei
2015-01-01
Personalized predictive models are customized for an individual patient and trained using information from similar patients. Compared to global models trained on all patients, they have the potential to produce more accurate risk scores and capture more relevant risk factors for individual patients. This paper presents an approach for building personalized predictive models and generating personalized risk factor profiles. A locally supervised metric learning (LSML) similarity measure is trained for diabetes onset and used to find clinically similar patients. Personalized risk profiles are created by analyzing the parameters of the trained personalized logistic regression models. A 15,000 patient data set, derived from electronic health records, is used to evaluate the approach. The predictive results show that the personalized models can outperform the global model. Cluster analysis of the risk profiles show groups of patients with similar risk factors, differences in the top risk factors for different groups of patients and differences between the individual and global risk factors.
Factors Resulting in Micron Indentation Hardness Descending in Indentation Tests
Institute of Scientific and Technical Information of China (English)
Li Min; Chen Weimin
2009-01-01
hardness decrease can be bated if the continuous stiffness measurement technique is not adopted; this indicates that the test method itself may also be one of the factors causing the hardness being descended.
Chou-Yang model and PHI form factor
Energy Technology Data Exchange (ETDEWEB)
Fazal-e-Aleem; Saleem, M.; Rafique, M.
1988-03-01
By using the deduced differential cross-section data for PHIp elastic scattering at 175 GeV/c in the Chou-Yang model, the PHI form factor has been computed and parametrized. Then in conjunction with the proton form factor this form factor is used in the pristine Chou-Yang model to obtain differential cross-section data at Fermilab energies. The theoretical results agree with the experimental measurements, endorsing the conjecture that the hadronic form factor of neutral particle is proportional to its magnetic form factor.
Modeling clicks beyond the first result page
Chuklin, A.; Serdyukov, P.; de Rijke, M.
2013-01-01
Most modern web search engines yield a list of documents of a fixed length (usually 10) in response to a user query. The next ten search results are usually available in one click. These documents either replace the current result page or are appended to the end. Hence, in order to examine more
Modeling clicks beyond the first result page
Chuklin, A.; Serdyukov, P.; de Rijke, M.
2013-01-01
Most modern web search engines yield a list of documents of a fixed length (usually 10) in response to a user query. The next ten search results are usually available in one click. These documents either replace the current result page or are appended to the end. Hence, in order to examine more docu
Bayesian Constrained-Model Selection for Factor Analytic Modeling
Peeters, Carel F.W.
2016-01-01
My dissertation revolves around Bayesian approaches towards constrained statistical inference in the factor analysis (FA) model. Two interconnected types of restricted-model selection are considered. These types have a natural connection to selection problems in the exploratory FA (EFA) and confirmatory FA (CFA) model and are termed Type I and Type II model selection. Type I constrained-model selection is taken to mean the determination of the appropriate dimensionality of a model. This type ...
Engineering model development and test results
Wellman, John A.
1993-08-01
The correctability of the primary mirror spherical error in the Wide Field/Planetary Camera (WF/PC) is sensitive to the precise alignment of the incoming aberrated beam onto the corrective elements. Articulating fold mirrors that provide +/- 1 milliradian of tilt in 2 axes are required to allow for alignment corrections in orbit as part of the fix for the Hubble space telescope. An engineering study was made by Itek Optical Systems and the Jet Propulsion Laboratory (JPL) to investigate replacement of fixed fold mirrors within the existing WF/PC optical bench with articulating mirrors. The study contract developed the base line requirements, established the suitability of lead magnesium niobate (PMN) actuators and evaluated several tilt mechanism concepts. Two engineering model articulating mirrors were produced to demonstrate the function of the tilt mechanism to provide +/- 1 milliradian of tilt, packaging within the space constraints and manufacturing techniques including the machining of the invar tilt mechanism and lightweight glass mirrors. The success of the engineering models led to the follow on design and fabrication of 3 flight mirrors that have been incorporated into the WF/PC to be placed into the Hubble Space Telescope as part of the servicing mission scheduled for late 1993.
DARK STARS: IMPROVED MODELS AND FIRST PULSATION RESULTS
Energy Technology Data Exchange (ETDEWEB)
Rindler-Daller, T.; Freese, K. [Department of Physics and Michigan Center for Theoretical Physics, University of Michigan, Ann Arbor, MI 48109 (United States); Montgomery, M. H.; Winget, D. E. [Department of Astronomy, McDonald Observatory and Texas Cosmology Center, University of Texas, Austin, TX 78712 (United States); Paxton, B. [Kavli Insitute for Theoretical Physics, University of California, Santa Barbara, CA 93106 (United States)
2015-02-01
We use the stellar evolution code MESA to study dark stars (DSs). DSs, which are powered by dark matter (DM) self-annihilation rather than by nuclear fusion, may be the first stars to form in the universe. We compute stellar models for accreting DSs with masses up to 10{sup 6} M {sub ☉}. The heating due to DM annihilation is self-consistently included, assuming extended adiabatic contraction of DM within the minihalos in which DSs form. We find remarkably good overall agreement with previous models, which assumed polytropic interiors. There are some differences in the details, with positive implications for observability. We found that, in the mass range of 10{sup 4}-10{sup 5} M {sub ☉}, our DSs are hotter by a factor of 1.5 than those in Freese et al., are smaller in radius by a factor of 0.6, denser by a factor of three to four, and more luminous by a factor of two. Our models also confirm previous results, according to which supermassive DSs are very well approximated by (n = 3)-polytropes. We also perform a first study of DS pulsations. Our DS models have pulsation modes with timescales ranging from less than a day to more than two years in their rest frames, at z ∼ 15, depending on DM particle mass and overtone number. Such pulsations may someday be used to identify bright, cool objects uniquely as DSs; if properly calibrated, they might, in principle, also supply novel standard candles for cosmological studies.
Microplasticity of MMC. Experimental results and modelling
Energy Technology Data Exchange (ETDEWEB)
Maire, E. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France)); Lormand, G. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France)); Gobin, P.F. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France)); Fougeres, R. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France))
1993-11-01
The microplastic behavior of several MMC is investigated by means of tension and compression tests. This behavior is assymetric : the proportional limit is higher in tension than in compression but the work hardening rate is higher in compression. These differences are analysed in terms of maxium of the Tresca's shear stress at the interface (proportional limit) and of the emission of dislocation loops during the cooling (work hardening rate). On another hand, a model is proposed to calculate the value of the yield stress, describing the composite as a material composed of three phases : inclusion, unaffected matrix and matrix surrounding the inclusion having a gradient in the density of the thermally induced dilocations. (orig.).
Continuous utility factor in segregation models
Roy, Parna; Sen, Parongama
2016-02-01
We consider the constrained Schelling model of social segregation in which the utility factor of agents strictly increases and nonlocal jumps of the agents are allowed. In the present study, the utility factor u is defined in a way such that it can take continuous values and depends on the tolerance threshold as well as the fraction of unlike neighbors. Two models are proposed: in model A the jump probability is determined by the sign of u only, which makes it equivalent to the discrete model. In model B the actual values of u are considered. Model A and model B are shown to differ drastically as far as segregation behavior and phase transitions are concerned. In model A, although segregation can be achieved, the cluster sizes are rather small. Also, a frozen state is obtained in which steady states comprise many unsatisfied agents. In model B, segregated states with much larger cluster sizes are obtained. The correlation function is calculated to show quantitatively that larger clusters occur in model B. Moreover for model B, no frozen states exist even for very low dilution and small tolerance parameter. This is in contrast to the unconstrained discrete model considered earlier where agents can move even when utility remains the same. In addition, we also consider a few other dynamical aspects which have not been studied in segregation models earlier.
Factorized domain wall partition functions in trigonometric vertex models
Foda, O; Zuparic, M
2007-01-01
We obtain factorized domain wall partition functions for two sets of trigonometric vertex models: 1. The N-state Deguchi-Akutsu models, for N = {2, 3, 4} (and conjecture the result for all N >= 5), and 2. The sl(r+1|s+1) Perk-Schultz models, for {r, s = \\N}, where (given the symmetries of these models) the result is independent of {r, s}.
Hayduk, Leslie
2014-01-01
Researchers using factor analysis tend to dismiss the significant ill fit of factor models by presuming that if their factor model is close-to-fitting, it is probably close to being properly causally specified. Close fit may indeed result from a model being close to properly causally specified, but close-fitting factor models can also be seriously…
Hayduk, Leslie
2014-01-01
Researchers using factor analysis tend to dismiss the significant ill fit of factor models by presuming that if their factor model is close-to-fitting, it is probably close to being properly causally specified. Close fit may indeed result from a model being close to properly causally specified, but close-fitting factor models can also be seriously…
Integers without Large Prime Factors in Short Intervals: Conditional Results
Indian Academy of Sciences (India)
Goutam Pal; Satadal Ganguly
2010-11-01
Under the Riemann hypothesis and the conjecture that the order of growth of the argument of $(1/2+it)$ is bounded by $(\\log t)^{\\frac{1}{2}+o(1)}$, we show that for any given > 0 the interval $(X, X+\\sqrt{X}(\\log X)^{1/2+o(1)}]$ contains an integer having no prime factor exceeding $X^$ for all sufficiently large.
Infrapopliteal Percutaneous Transluminal Balloon Angioplasty: Clinical Results and Influence Factors
Energy Technology Data Exchange (ETDEWEB)
Song, Jang Hyeon; Lee, Seung Jin; Jung, Hye Doo; Lim, Jae Hoon; Chang, Nam Kyu; Yim, Nam Yeol; Kim, Jae Kyu [Dept. of Radiology, Chonnam National University Hospital, Gwangju (Korea, Republic of); Lee, Keun Bae [Dept. of Radiology, Chonnam National University Hospital, Gwangju (Korea, Republic of)
2011-09-15
To assess the efficacy of percutaneous transluminal angioplasty (PTA) in patients with infrapopliteal arterial disease, and to determine the influencing factor for prognosis. A total of 55 patients (60 limbs) with infrapopliteal arterial stenosis or occlusion underwent PTA. Atherosclerotic risk factors, clinical symptoms, TransAtlantic Inter-Society Consensus (TASC) classification, and vascular wall calcification were evaluated before PTA. The number of patent infrapopliteal arteries was estimated, and the outcome was evaluated by symptom relief and limb salvage. Technical success was achieved in 53/60 limbs (88.3%) and 81/93 arteries (87.1%), TASC classification (p = 0.038) and vascular calcification (p = 0.002) influenced on technical failure. During follow-up, 26 of 55 limbs (47%) achieved symptom relief and 42/55 limbs (76%) underwent limb salvage. Non-diabetic patients (9/12, 75%) were superior to diabetic patients (17/43, 40%) in terms of symptom relief (p = 0.024). TASC classification and vascular wall calcification influenced on symptom relief and limb salvage. The number of patent infrapopliteal arteries after PTA influenced symptom relief (p < 0.001) and limb amputation (p = 0.003). PTA in patients with chronic critical limb ischemia is worthwhile as a primary treatment. The influence factors should be considered before PTA, and PTA should be performed in as many involved arteries as possible.
The asset pricing model of musharakah factors
Simon, Shahril; Omar, Mohd; Lazam, Norazliani Md
2015-02-01
The existing three-factor model developed by Fama and French for conventional investment was formulated based on risk-free rates element in which contradict with Shariah principles. We note that the underlying principles that govern Shariah investment were mutual risk and profit sharing between parties, the assurance of fairness for all and that transactions were based on an underlying asset. In addition, the three-factor model did not exclude stock that was not permissible by Shariah such as financial services based on riba (interest), gambling operator, manufacture or sale of non-halal products or related products and other activities deemed non-permissible according to Shariah. Our approach to construct the factor model for Shariah investment was based on the basic tenets of musharakah in tabulating the factors. We start by noting that Islamic stocks with similar characteristics should have similar returns and risks. This similarity between Islamic stocks was defined by the similarity of musharakah attributes such as business, management, profitability and capital. These attributes define factor exposures (or betas) to factors. The main takeaways were that musharakah attributes we chose had explain stock returns well in cross section and were significant in different market environments. The management factor seemed to be responsible for the general dynamics of the explanatory power.
Model independent analysis of dark energy I: Supernova fitting result
Gong, Y
2004-01-01
The nature of dark energy is a mystery to us. This paper uses the supernova data to explore the property of dark energy by some model independent methods. We first Talyor expanded the scale factor $a(t)$ to find out the deceleration parameter $q_0<0$. This result just invokes the Robertson-Walker metric. Then we discuss several different parameterizations used in the literature. We find that $\\Omega_{\\rm DE0}$ is almost less than -1 at $1\\sigma$ level. We also find that the transition redshift from deceleration phase to acceleration phase is $z_{\\rm T}\\sim 0.3$.
Human factors engineering program review model
Energy Technology Data Exchange (ETDEWEB)
1994-07-01
The staff of the Nuclear Regulatory Commission is performing nuclear power plant design certification reviews based on a design process plan that describes the human factors engineering (HFE) program elements that are necessary and sufficient to develop an acceptable detailed design specification and an acceptable implemented design. There are two principal reasons for this approach. First, the initial design certification applications submitted for staff review did not include detailed design information. Second, since human performance literature and industry experiences have shown that many significant human factors issues arise early in the design process, review of the design process activities and results is important to the evaluation of an overall design. However, current regulations and guidance documents do not address the criteria for design process review. Therefore, the HFE Program Review Model (HFE PRM) was developed as a basis for performing design certification reviews that include design process evaluations as well as review of the final design. A central tenet of the HFE PRM is that the HFE aspects of the plant should be developed, designed, and evaluated on the basis of a structured top-down system analysis using accepted HFE principles. The HFE PRM consists of ten component elements. Each element in divided into four sections: Background, Objective, Applicant Submittals, and Review Criteria. This report describes the development of the HFE PRM and gives a detailed description of each HFE review element.
Dark Stars: Improved Models and First Pulsation Results
Rindler-Daller, Tanja; Freese, Katherine; Winget, Donald E; Paxton, Bill
2014-01-01
(Abridged) We use the stellar evolution code MESA to study dark stars. Dark stars (DSs), which are powered by dark matter (DM) self-annihilation rather than by nuclear fusion, may be the first stars to form in the Universe. We compute stellar models for accreting DSs with masses up to 10^6 M_sun. While previous calculations were limited to polytropic interiors, our current calculations use MESA, a modern stellar evolution code to solve the equations of stellar structure. The heating due to DM annihilation is self-consistently included, assuming extended adiabatic contraction of DM within the minihalos in which DSs form. We find remarkably good overall agreement with the basic results of previous models. There are some differences, however, in the details, with positive implications for observability of DSs. We found that, in the mass range of 10^4 - 10^5 M_sun, using MESA, our DSs are hotter by a factor of 1.5 than those in Freese et al.(2010), are smaller in radius by a factor of 0.6, denser by a factor of 3...
Factor Copula Models for Replicated Spatial Data
Krupskii, Pavel
2016-12-19
We propose a new copula model that can be used with replicated spatial data. Unlike the multivariate normal copula, the proposed copula is based on the assumption that a common factor exists and affects the joint dependence of all measurements of the process. Moreover, the proposed copula can model tail dependence and tail asymmetry. The model is parameterized in terms of a covariance function that may be chosen from the many models proposed in the literature, such as the Matérn model. For some choice of common factors, the joint copula density is given in closed form and therefore likelihood estimation is very fast. In the general case, one-dimensional numerical integration is needed to calculate the likelihood, but estimation is still reasonably fast even with large data sets. We use simulation studies to show the wide range of dependence structures that can be generated by the proposed model with different choices of common factors. We apply the proposed model to spatial temperature data and compare its performance with some popular geostatistics models.
Detecting Social Desirability Bias Using Factor Mixture Models
Leite, Walter L.; Cooper, Lou Ann
2010-01-01
Based on the conceptualization that social desirable bias (SDB) is a discrete event resulting from an interaction between a scale's items, the testing situation, and the respondent's latent trait on a social desirability factor, we present a method that makes use of factor mixture models to identify which examinees are most likely to provide…
Hidden Markov Models with Factored Gaussian Mixtures Densities
Institute of Scientific and Technical Information of China (English)
LI Hao-zheng; LIU Zhi-qiang; ZHU Xiang-hua
2004-01-01
We present a factorial representation of Gaussian mixture models for observation densities in Hidden Markov Models(HMMs), which uses the factorial learning in the HMM framework. We derive the reestimation formulas for estimating the factorized parameters by the Expectation Maximization (EM) algorithm. We conduct several experiments to compare the performance of this model structure with Factorial Hidden Markov Models(FHMMs) and HMMs, some conclusions and promising empirical results are presented.
Results of chemo-radiotherapy and prognostic factors of small cell lung cancer.
Shikaura, S; Kawa, S; Yoshida, M; Yonezu, S
1991-01-01
We studied the therapeutic results and prognostic factors in 63 cases of small cell lung cancer (SCLC) experienced in our hospital over the past eight years. In the group initially treated with combination chemotherapy using COMP-VAD, the survival period was significantly prolonged. Use of adjuvant radiotherapy from the beginning had no effect on improvement in the survival period, but the period until local recurrences tended to be prolonged. Prognostic factors influencing survival were analyzed by the log rank test and generalized Wilcoxon test and multivariate analysis by the proportional hazard model of Cox. Statistical significance using univariate analysis was found for six factors (PS, clinical stage, LDH, albumin, treatment protocols, treatment response). The strong prognostic factors determined by multivariate analysis were, in the order of importance, chemotherapy protocol, initial PS, and treatment response.
Smits, Iris A.M.; Timmerman, Marieke E.; Stegeman, Alwin
Maximum likelihood estimation of the linear factor model for continuous items assumes normally distributed item scores. We consider deviations from normality by means of a skew-normally distributed factor model or a quadratic factor model. We show that the item distributions under a skew-normal
Verification modeling study for the influential factors of secondary clarifier
Gao, Haiwen
2016-01-01
A numerical Quasi 3-D model of secondary clarifier is applied to verify the data obtained through the literature and analyze the influential factors for secondary clarifiers. The data from the papers provide the input parameters for the model. During this study, several influential factors (density waterfall; surface overflow rate; solids loading rate; solids-settling characteristics; mixed liquor suspended solid; clarifier geometry) are tested. The results show that there are some difference...
Examination of the Factors Influencing the Exam Results
Sitku-Görömbei, Cecília
2009-01-01
The defectiveness of the effectiveness of the Hungarian general education revealed in the PISA survey appears in the higher education as well. The "Introduction to Informatics" subject has one of the lowest exam results among the students of the College of Nyíregyháza majoring in Computer Program Designer and Teacher of Computer Science.…
Aging Successfully: A Four-Factor Model
Lee, Pai-Lin; Lan, William; Yen, Tung-Wen
2011-01-01
The study was designed to validate a model for a successful aging process and examine the gender differences in the aging process. Three hundred twelve participants who were 65 or older completed a Taiwan Social Change Survey that measures four factors that define successful aging process: including physical, psychological, social support, and…
Multistructure Statistical Model Applied To Factor Analysis
Bentler, Peter M.
1976-01-01
A general statistical model for the multivariate analysis of mean and covariance structures is described. Matrix calculus is used to develop the statistical aspects of one new special case in detail. This special case separates the confounding of principal components and factor analysis. (DEP)
Aging Successfully: A Four-Factor Model
Lee, Pai-Lin; Lan, William; Yen, Tung-Wen
2011-01-01
The study was designed to validate a model for a successful aging process and examine the gender differences in the aging process. Three hundred twelve participants who were 65 or older completed a Taiwan Social Change Survey that measures four factors that define successful aging process: including physical, psychological, social support, and…
Global Quantitative Modeling of Chromatin Factor Interactions
Zhou, Jian; Troyanskaya, Olga G.
2014-01-01
Chromatin is the driver of gene regulation, yet understanding the molecular interactions underlying chromatin factor combinatorial patterns (or the “chromatin codes”) remains a fundamental challenge in chromatin biology. Here we developed a global modeling framework that leverages chromatin profiling data to produce a systems-level view of the macromolecular complex of chromatin. Our model ultilizes maximum entropy modeling with regularization-based structure learning to statistically dissect dependencies between chromatin factors and produce an accurate probability distribution of chromatin code. Our unsupervised quantitative model, trained on genome-wide chromatin profiles of 73 histone marks and chromatin proteins from modENCODE, enabled making various data-driven inferences about chromatin profiles and interactions. We provided a highly accurate predictor of chromatin factor pairwise interactions validated by known experimental evidence, and for the first time enabled higher-order interaction prediction. Our predictions can thus help guide future experimental studies. The model can also serve as an inference engine for predicting unknown chromatin profiles — we demonstrated that with this approach we can leverage data from well-characterized cell types to help understand less-studied cell type or conditions. PMID:24675896
New DNS and modeling results for turbulent pipe flow
Johansson, Arne; El Khoury, George; Grundestam, Olof; Schlatter, Philipp; Brethouwer, Geert; Linne Flow Centre Team
2013-11-01
The near-wall region of turbulent pipe and channel flows (as well as zero-pressure gradient boundary layers) have been shown to exhibit a very high degree of similarity in terms of all statistical moments and many other features, while even the mean velocity profile in the two cases exhibits significant differences between in the outer region. The wake part of the profile, i.e. the deviation from the log-law, in the outer region is of substantially larger amplitude in pipe flow as compared to channel flow (although weaker than in boundary layer flow). This intriguing feature has been well known but has no simple explanation. Model predictions typically give identical results for the two flows. We have analyzed a new set of DNS for pipe and channel flows (el Khoury et al. 2013, Flow, Turbulence and Combustion) for friction Reynolds numbers up to 1000 and made comparing calculations with differential Reynolds stress models (DRSM). We have strong indications that the key factor behind the difference in mean velocity in the outer region can be coupled to differences in the turbulent diffusion in this region. This is also supported by DRSM results, where interesting differences are seen depending on the sophistication of modeling the turbulent diffusion coefficient.
An alternative method for centrifugal compressor loading factor modelling
Galerkin, Y.; Drozdov, A.; Rekstin, A.; Soldatova, K.
2017-08-01
The loading factor at design point is calculated by one or other empirical formula in classical design methods. Performance modelling as a whole is out of consideration. Test data of compressor stages demonstrates that loading factor versus flow coefficient at the impeller exit has a linear character independent of compressibility. Known Universal Modelling Method exploits this fact. Two points define the function – loading factor at design point and at zero flow rate. The proper formulae include empirical coefficients. A good modelling result is possible if the choice of coefficients is based on experience and close analogs. Earlier Y. Galerkin and K. Soldatova had proposed to define loading factor performance by the angle of its inclination to the ordinate axis and by the loading factor at zero flow rate. Simple and definite equations with four geometry parameters were proposed for loading factor performance calculated for inviscid flow. The authors of this publication have studied the test performance of thirteen stages of different types. The equations are proposed with universal empirical coefficients. The calculation error lies in the range of plus to minus 1,5%. The alternative model of a loading factor performance modelling is included in new versions of the Universal Modelling Method.
Barnes, Jennifer; Prescott, Tim; Muncer, Steven
2012-12-01
The purpose of this investigation was to compare the goodness-of-fit of a one factor model with the four factor model proposed by Fairburn (2008) and the three factor model proposed by Peterson and colleagues (2007) for the Eating Disorder Examination Questionnaire (EDE-Q 6.0) (Fairburn and Beglin, 1994). Using a cross-sectional design, the EDE-Q was completed by 569 adults recruited from universities and eating disorder charities in the UK. Confirmatory factor analysis (CFA) was carried out for both the student and non-student groups. CFA indicated that Peterson et al.'s (2007) three factor model was the best fit for both groups within the current data sample. Acceptable levels of internal reliability were observed and there was clear evidence for a hierarchical factor of eating disorder. The results of this study provide support for the three factor model of the EDE-Q suggested by Peterson and colleagues (2007) in that this model was appropriate for both the student and non-student sample populations. Copyright © 2012 Elsevier Ltd. All rights reserved.
Factor Model Forecasting of Inflation in Croatia
Directory of Open Access Journals (Sweden)
Davor Kunovac
2007-12-01
Full Text Available This paper tests whether information derived from 144 economic variables (represented by only a few constructed factors can be used for the forecasting of consumer prices in Croatia. The results obtained show that the use of one factor enhances the precision of the benchmark model’s ability to forecast inflation. The methodology used is sufficiently general to be able to be applied directly for the forecasting of other economic variables.
Connections between Graphical Gaussian Models and Factor Analysis
Salgueiro, M. Fatima; Smith, Peter W. F.; McDonald, John W.
2010-01-01
Connections between graphical Gaussian models and classical single-factor models are obtained by parameterizing the single-factor model as a graphical Gaussian model. Models are represented by independence graphs, and associations between each manifest variable and the latent factor are measured by factor partial correlations. Power calculations…
Smits, Iris A M; Timmerman, Marieke E; Stegeman, Alwin
2016-05-01
Maximum likelihood estimation of the linear factor model for continuous items assumes normally distributed item scores. We consider deviations from normality by means of a skew-normally distributed factor model or a quadratic factor model. We show that the item distributions under a skew-normal factor are equivalent to those under a quadratic model up to third-order moments. The reverse only holds if the quadratic loadings are equal to each other and within certain bounds. We illustrate that observed data which follow any skew-normal factor model can be so well approximated with the quadratic factor model that the models are empirically indistinguishable, and that the reverse does not hold in general. The choice between the two models to account for deviations of normality is illustrated by an empirical example from clinical psychology. © 2015 The British Psychological Society.
RESULTS OF INTERBANK EXCHANGE RATES FORECASTING USING STATE SPACE MODEL
Directory of Open Access Journals (Sweden)
Muhammad Kashif
2008-07-01
Full Text Available This study evaluates the performance of three alternative models for forecasting daily interbank exchange rate of U.S. dollar measured in Pak rupees. The simple ARIMA models and complex models such as GARCH-type models and a state space model are discussed and compared. Four different measures are used to evaluate the forecasting accuracy. The main result is the state space model provides the best performance among all the models.
Scale Factor Self-Dual Cosmological Models
dS, U Camara; Sotkov, G M
2015-01-01
We implement a conformal time scale factor duality for Friedmann-Robertson-Walker cosmological models, which is consistent with the weak energy condition. The requirement for self-duality determines the equations of state for a broad class of barotropic fluids. We study the example of a universe filled with two interacting fluids, presenting an accelerated and a decelerated period, with manifest UV/IR duality. The associated self-dual scalar field interaction turns out to coincide with the "radiation-like" modified Chaplygin gas models. We present an equivalent realization of them as gauged K\\"ahler sigma models (minimally coupled to gravity) with very specific and interrelated K\\"ahler- and super-potentials. Their applications in the description of hilltop inflation and also as quintessence models for the late universe are discussed.
Modeling Relational Data via Latent Factor Blockmodel
Gao, Sheng; Gallinari, Patrick
2012-01-01
In this paper we address the problem of modeling relational data, which appear in many applications such as social network analysis, recommender systems and bioinformatics. Previous studies either consider latent feature based models but disregarding local structure in the network, or focus exclusively on capturing local structure of objects based on latent blockmodels without coupling with latent characteristics of objects. To combine the benefits of the previous work, we propose a novel model that can simultaneously incorporate the effect of latent features and covariates if any, as well as the effect of latent structure that may exist in the data. To achieve this, we model the relation graph as a function of both latent feature factors and latent cluster memberships of objects to collectively discover globally predictive intrinsic properties of objects and capture latent block structure in the network to improve prediction performance. We also develop an optimization transfer algorithm based on the general...
Satisfiers and Dissatisfiers: A Two-Factor Model for Website Design and Evaluation.
Zhang, Ping; von Dran, Gisela M.
2000-01-01
Investigates Web site design factors and their impact from a theoretical perspective. Presents a two-factor model that can guide Web site design and evaluation. According to the model, there are two types of design factors: hygiene and motivator. Results showed that the two-factor model provides a means for Web-user interface studies. Provides…
Human Factors Engineering Program Review Model
2004-02-01
AA NUREG -0711,Rev. 2 Human Factors Engineering Program Review Model 20081009191 I i m To] Bi U.S. Nuclear Regulatory Commission Office of...Material As of November 1999, you may electronically access NUREG -series publications and other NRC records at NRC’s Public Electronic Reading Room at...http://www.nrc.qov/readinq-rm.html. Publicly released records include, to name a few, NUREG -series publications; Federal Register notices; applicant
Evolution of the distance scale factor and the Hubble parameter in the light of Plancks results
Crevecoeur, Guibert U
2016-01-01
As the 2015 results of Plancks mission have recently been made available, it is interesting to check the evolution of the scale factor and of the Hubble parameter in the light of these results. Two models in line with Einsteins field equations and with the hot big bang scenario for a flat Universe are used to allow a comparison : (1) the classical one using density parameters for matter content (baryonic and dark matter) and dark energy ; (2) an alternative model, already used in the past, and assuming the Hubble parameter to contain a term constant in time. Both models are coherent with each other except for some discrepancy about the density, which can be ascribed to the different hypotheses made. This opens a way for further interpretation of the origin of dark matter and dark energy.
Subsea Permafrost Climate Modeling - Challenges and First Results
Rodehacke, C. B.; Stendel, M.; Marchenko, S. S.; Christensen, J. H.; Romanovsky, V. E.; Nicolsky, D.
2015-12-01
Recent observations indicate that the East Siberian Arctic Shelf (ESAS) releases methane, which stems from shallow hydrate seabed reservoirs. The total amount of carbon within the ESAS is so large that release of only a small fraction, for example via taliks, which are columns of unfrozen sediment within the permafrost, could impact distinctly the global climate. Therefore it is crucial to simulate the future fate of ESAS' subsea permafrost with regard to changing atmospheric and oceanic conditions. However only very few attempts to address the vulnerability of subsea permafrost have been made, instead most studies have focused on the evolution of permafrost since the Late Pleistocene ocean transgression, approximately 14000 years ago.In contrast to land permafrost modeling, any attempt to model the future fate of subsea permafrost needs to consider several additional factors, in particular the dependence of freezing temperature on water depth and salt content and the differences in ground heat flux depending on the seabed properties. Also the amount of unfrozen water in the sediment needs to be taken into account. Using a system of coupled ocean, atmosphere and permafrost models will allow us to capture the complexity of the different parts of the system and evaluate the relative importance of different processes. Here we present the first results of a novel approach by means of dedicated permafrost model simulations. These have been driven by conditions of the Laptev Sea region in East Siberia. By exploiting the ensemble approach, we will show how uncertainties in boundary conditions and applied forcing scenarios control the future fate of the sub sea permafrost.
del Pino Pérez, Antonio; Ibáñez Fernández, Ignacio; Bosa Ojeda, Francisco; Dorta González, Ruth; Gaos Miezoso, María Teresa
2012-02-01
The objective of this study was to validate in a sample of 205 coronary patients a factor model for the BDI-II, especially a model that would allow for modeling of depressive symptoms after explicitly removing bias related to somatic symptoms of depression that would overlap those of heart disease. Exploratory and confirmatory factor analyses for ordinal data were conducted. A one-factor model, six correlated two-factor models and, derivatives thereof, seven models with a single General Depression factor and two uncorrelated factors, were analyzed. Exploratory analysis extracted two factors, Somatic-affective and Cognitive. Confirmatory factor analyses showed the worst fit for the one-factor model. Two-factor models were surpassed in goodness of fit by the models of general-factor and group factors. Among these, the General, Somatic-affective and Cognitive (G-Sa-C) model of Beck with students is noteworthy. The reduced General, Somatic and Cognitive (G-S-C) model of Ward showed the worst goodness of fit. Our model surpasses the cutoff criteria of all fit indexes. We conclude that the inclusion of a general-factor and group factors in all the models surpasses the results of G-S-C model and, therefore, questions it. The G-Sa-C model is strengthened.
Consumer's Online Shopping Influence Factors and Decision-Making Model
Yan, Xiangbin; Dai, Shiliang
Previous research on online consumer behavior has mostly been confined to the perceived risk which is used to explain those barriers for purchasing online. However, perceived benefit is another important factor which influences consumers’ decision when shopping online. As a result, an integrated consumer online shopping decision-making model is developed which contains three elements—Consumer, Product, and Web Site. This model proposed relative factors which influence the consumers’ intention during the online shopping progress, and divided them into two different dimensions—mentally level and material level. We tested those factors with surveys, from both online volunteers and offline paper surveys with more than 200 samples. With the help of SEM, the experimental results show that the proposed model and method can be used to analyze consumer’s online shopping decision-making process effectively.
Genes and lifestyle factors in obesity: results from 12 462 subjects from MONICA/KORA
Holzapfel, Christina; Grallert, Harald; Huth, Cornelia; Wahl, Simone; Fischer, Beate; Döring, Angela; Rückert, Ina M; Hinney, Anke; Hebebrand, Johannes; Wichmann, H.-Erich; Hauner, Hans; Illig, Thomas; Heid, Iris M
2011-01-01
Background Data from meta-analyses of genome-wide association studies provided evidence for an association of polymorphisms with body mass index (BMI), and gene expression results indicated a role of these variants in the hypothalamus. It was consecutively hypothesized that these associations might be evoked by a modulation of nutritional intake or energy expenditure. Objective It was our aim to investigate the association of these genetic factors with BMI in a large homogenous population-based sample to explore the association of these polymorphisms with lifestyle factors related to nutritional intake or energy expenditure, and whether such lifestyle factors could be mediators of the detected single-nucleotide polymorphism (SNP)-association with BMI. It was a further aim to compare the proportion of BMI explained by genetic factors with the one explained by lifestyle factors. Design The association of seven polymorphisms in or near the genes NEGR1, TMEM18, MTCH2, FTO, MC4R, SH2B1and KCTD15 was analyzed in 12 462 subjects from the population-based MONICA/KORA Augsburg study. Information on lifestyle factors was based on standardized questionnaires. For statistical analysis, regression-based models were used. Results The minor allele of polymorphism rs6548238 C>T (TMEM18) was associated with lower BMI (−0.418 kg/m2, p=1.22×10−8), and of polymorphisms rs9935401 G>A (FTO) and rs7498665 A>G (SH2B1) with increased BMI (0.290 kg/m2, p=2.85×10−7 and 0.145 kg/m2, p=9.83×10−3). The other polymorphisms were not significantly associated. Lifestyle factors were correlated with BMI and explained 0.037 % of the BMI variance as compared to 0.006 % of explained variance by the associated genetic factors. The genetic variants associated with BMI were not significantly associated with lifestyle factors and there was no evidence of lifestyle factors mediating the SNP-BMI association. Conclusions Our data first confirm the findings for TMEM18 with BMI in a single study on
Treatment for liver metastases from breast cancer: Results and prognostic factors
Institute of Scientific and Technical Information of China (English)
Xiao-Ping Li; Zhi-Qiang Meng; Wei-Jian Guo; Jie Li
2005-01-01
AIM: Liver metastases from breast cancer (BCLM) are associated with poor prognosis. Cytotoxic chemotherapy can result in regression of tumor lesions and a decrease in symptoms. Available data, in the literature, also suggest a subgroup of patients rraay berefit from surgery, but few talked about transcatheter arterial chemoembolization (TACE).We report the results of TACE and systemic chemotherapy for patients with liver metastases from breast cancer and evaluate the prognostic factors. METHODS: Forty-eight patients with liver metastases, from proved breast primary cancer were treated with TACEor systemic chemotherapy between January 1995 and December 2000. Treatment results were assessed according to WHO criteria, along with analysis of prognostic factors for survival using Cox regression model.RESULTS: The median follow-up was 28 mo (1-72 mo). Response rates were calculated for the TACE group and chemotherapy group, being 35.7% and 7.1%,respectively. The difference was significant. The one-, two- and three-year Survival rates for the TACE group were 63.04%, 30.35%, and 13.01%, and those for the systemic chemotherapy group were 33.88%, 11.29%, and 0%. According to univariate analysis, variables significantly associated with survival were the lymph node status of the primary cancer, the clinical stage of liver metastases, the Child-Pugh grade, loss of weight. Other factors such as age, the intervals between the primary to the metastases, the maximal diameter of the liver metastases, the number of liver metastases, extrahepatic metastasis showed no prognostic significances. These factors mentioned above such as the lymph node status of the primary cancer, the clinical stage of liver metastases, the Child-Pugh grade, loss of weight were also independent factors in multivariate analysis.CONCLUSION: TACE treatment of liver metastases from breast cancer may prolong survival in certain patients. This approach offers new promise for the curative treatment of the patients
Statistical Mechanical Models of Integer Factorization Problem
Nakajima, Chihiro H.; Ohzeki, Masayuki
2017-01-01
We formulate the integer factorization problem via a formulation of the searching problem for the ground state of a statistical mechanical Hamiltonian. The first passage time required to find a correct divisor of a composite number signifies the exponential computational hardness. The analysis of the density of states of two macroscopic quantities, i.e., the energy and the Hamming distance from the correct solutions, leads to the conclusion that the ground state (correct solution) is completely isolated from the other low-energy states, with the distance being proportional to the system size. In addition, the profile of the microcanonical entropy of the model has two peculiar features that are each related to two marked changes in the energy region sampled via Monte Carlo simulation or simulated annealing. Hence, we find a peculiar first-order phase transition in our model.
Some Results on the Problem of Updating the Hyperbolic Matrix Factorizations
Institute of Scientific and Technical Information of China (English)
Hanyu LI; Hu YANG
2013-01-01
This paper considers the updating problem of the hyperbolic matrix factorizations.The sufficient conditions for the existence of the updated hyperbolic matrix factorizations are first provided.Then,some differential inequalities and first order perturbation expansions for the updated hyperbolic factors are derived.These results generalize the corresponding ones for the updating problem of the classical QR factorization obtained by Jiguang SUN.
Uncovering Transcriptional Regulatory Networks by Sparse Bayesian Factor Model
Meng, Jia; Zhang, Jianqiu(Michelle); Qi, Yuan(Alan); Chen, Yidong; Huang, Yufei
2010-12-01
The problem of uncovering transcriptional regulation by transcription factors (TFs) based on microarray data is considered. A novel Bayesian sparse correlated rectified factor model (BSCRFM) is proposed that models the unknown TF protein level activity, the correlated regulations between TFs, and the sparse nature of TF-regulated genes. The model admits prior knowledge from existing database regarding TF-regulated target genes based on a sparse prior and through a developed Gibbs sampling algorithm, a context-specific transcriptional regulatory network specific to the experimental condition of the microarray data can be obtained. The proposed model and the Gibbs sampling algorithm were evaluated on the simulated systems, and results demonstrated the validity and effectiveness of the proposed approach. The proposed model was then applied to the breast cancer microarray data of patients with Estrogen Receptor positive ([InlineEquation not available: see fulltext.]) status and Estrogen Receptor negative ([InlineEquation not available: see fulltext.]) status, respectively.
Uncovering Transcriptional Regulatory Networks by Sparse Bayesian Factor Model
Directory of Open Access Journals (Sweden)
Qi Yuan(Alan
2010-01-01
Full Text Available Abstract The problem of uncovering transcriptional regulation by transcription factors (TFs based on microarray data is considered. A novel Bayesian sparse correlated rectified factor model (BSCRFM is proposed that models the unknown TF protein level activity, the correlated regulations between TFs, and the sparse nature of TF-regulated genes. The model admits prior knowledge from existing database regarding TF-regulated target genes based on a sparse prior and through a developed Gibbs sampling algorithm, a context-specific transcriptional regulatory network specific to the experimental condition of the microarray data can be obtained. The proposed model and the Gibbs sampling algorithm were evaluated on the simulated systems, and results demonstrated the validity and effectiveness of the proposed approach. The proposed model was then applied to the breast cancer microarray data of patients with Estrogen Receptor positive ( status and Estrogen Receptor negative ( status, respectively.
van Schuur, Wyijbrandt H.; Kiers, Henk A.L.
Factor analysis of data that conform to the unfolding model often results in an extra factor. This artificial extra factor is particularly important when data that conform to a bipolar unidimensional unfolding scale are factor analyzed. One bipolar dimension is expected, but two factors are found
Electrical tortuosity, Kozeny’s factor and cementation factor modelled for chalk
DEFF Research Database (Denmark)
Katika, Konstantina; Fabricius, Ida Lykke
2015-01-01
Based on the electrical properties of chalk from the North Sea and Stevns Klint and on published data, we explore how klinkenberg corrected permeability from experimental data relate to porosity and electrical resistivity. In the current study we use electrical conductivity data of partially water......, to calculate permeability based on electrical resistivity data. We also calculate the permeability based on a simple porosity model. Finally, we redefine Kozeny’s factor, c, using Carman’s model based on tortuosity and the model based on porosity. This resulted in a third modelled permeability, which describes...
A Right Coprime Factorization of Neural State Space Models
DEFF Research Database (Denmark)
Bendtsen, Jan Dimon
2007-01-01
In recent years, various methods for identification of nonlinear systems in closed loop using open-loop approaches have received considerable attention. However, these methods rely on differentially coprime factorizations of the nonlinear plants, which can be difficult to compute in practice....... To address this issue, this paper presents various technical results leading up to explicit formulae for right coprime factorizations of neural state space models, i.e., nonlinear system models represented in state space using neural networks, which satisfy a Bezout identity. ...
Some results regarding the comparison of the Earth's atmospheric models
Directory of Open Access Journals (Sweden)
Šegan S.
2005-01-01
Full Text Available In this paper we examine air densities derived from our realization of aeronomic atmosphere models based on accelerometer measurements from satellites in a low Earth's orbit (LEO. Using the adapted algorithms we derive comparison parameters. The first results concerning the adjustment of the aeronomic models to the total-density model are given.
Functional dynamic factor models with application to yield curve forecasting
Hays, Spencer
2012-09-01
Accurate forecasting of zero coupon bond yields for a continuum of maturities is paramount to bond portfolio management and derivative security pricing. Yet a universal model for yield curve forecasting has been elusive, and prior attempts often resulted in a trade-off between goodness of fit and consistency with economic theory. To address this, herein we propose a novel formulation which connects the dynamic factor model (DFM) framework with concepts from functional data analysis: a DFM with functional factor loading curves. This results in a model capable of forecasting functional time series. Further, in the yield curve context we show that the model retains economic interpretation. Model estimation is achieved through an expectation- maximization algorithm, where the time series parameters and factor loading curves are simultaneously estimated in a single step. Efficient computing is implemented and a data-driven smoothing parameter is nicely incorporated. We show that our model performs very well on forecasting actual yield data compared with existing approaches, especially in regard to profit-based assessment for an innovative trading exercise. We further illustrate the viability of our model to applications outside of yield forecasting.
Higher-order models versus direct hierarchical models: g as superordinate or breadth factor?
Directory of Open Access Journals (Sweden)
GILLES E. GIGNAC
2008-03-01
Full Text Available Intelligence research appears to have overwhelmingly endorsed a superordinate (higher-order model conceptualization of g, in comparison to the relatively less well-known breadth conceptualization of g, as represented by the direct hierarchical model. In this paper, several similarities and distinctions between the indirect and direct hierarchical models are delineated. Based on the re-analysis of five correlation matrices, it was demonstrated via CFA that the conventional conception of g as a higher-order superordinate factor was likely not as plausible as a first-order breadth factor. The results are discussed in light of theoretical advantages of conceptualizing g as a first-order factor. Further, because the associations between group-factors and g are constrained to zero within a direct hierarchical model, previous observations of isomorphic associations between a lower-order group factor and g are questioned.
The Effect of Bathymetric Filtering on Nearshore Process Model Results
2009-01-01
Filtering on Nearshore Process Model Results 6. AUTHOR(S) Nathaniel Plant, Kacey L. Edwards, James M. Kaihatu, Jayaram Veeramony, Yuan-Huang L. Hsu...filtering on nearshore process model results Nathaniel G. Plant **, Kacey L Edwardsb, James M. Kaihatuc, Jayaram Veeramony b, Larry Hsu’’, K. Todd Holland...assimilation efforts that require this information. Published by Elsevier B.V. 1. Introduction Nearshore process models are capable of predicting
Solutions of two-factor models with variable interest rates
Li, Jinglu; Clemons, C. B.; Young, G. W.; Zhu, J.
2008-12-01
The focus of this work is on numerical solutions to two-factor option pricing partial differential equations with variable interest rates. Two interest rate models, the Vasicek model and the Cox-Ingersoll-Ross model (CIR), are considered. Emphasis is placed on the definition and implementation of boundary conditions for different portfolio models, and on appropriate truncation of the computational domain. An exact solution to the Vasicek model and an exact solution for the price of bonds convertible to stock at expiration under a stochastic interest rate are derived. The exact solutions are used to evaluate the accuracy of the numerical simulation schemes. For the numerical simulations the pricing solution is analyzed as the market completeness decreases from the ideal complete level to one with higher volatility of the interest rate and a slower mean-reverting environment. Simulations indicate that the CIR model yields more reasonable results than the Vasicek model in a less complete market.
Steel Containment Vessel Model Test: Results and Evaluation
Energy Technology Data Exchange (ETDEWEB)
Costello, J.F.; Hashimote, T.; Hessheimer, M.F.; Luk, V.K.
1999-03-01
A high pressure test of the steel containment vessel (SCV) model was conducted on December 11-12, 1996 at Sandia National Laboratories, Albuquerque, NM, USA. The test model is a mixed-scaled model (1:10 in geometry and 1:4 in shell thickness) of an improved Mark II boiling water reactor (BWR) containment. A concentric steel contact structure (CS), installed over the SCV model and separated at a nominally uniform distance from it, provided a simplified representation of a reactor shield building in the actual plant. The SCV model and contact structure were instrumented with strain gages and displacement transducers to record the deformation behavior of the SCV model during the high pressure test. This paper summarizes the conduct and the results of the high pressure test and discusses the posttest metallurgical evaluation results on specimens removed from the SCV model.
A quality metric for homology modeling: the H-factor
2011-01-01
Background The analysis of protein structures provides fundamental insight into most biochemical functions and consequently into the cause and possible treatment of diseases. As the structures of most known proteins cannot be solved experimentally for technical or sometimes simply for time constraints, in silico protein structure prediction is expected to step in and generate a more complete picture of the protein structure universe. Molecular modeling of protein structures is a fast growing field and tremendous works have been done since the publication of the very first model. The growth of modeling techniques and more specifically of those that rely on the existing experimental knowledge of protein structures is intimately linked to the developments of high resolution, experimental techniques such as NMR, X-ray crystallography and electron microscopy. This strong connection between experimental and in silico methods is however not devoid of criticisms and concerns among modelers as well as among experimentalists. Results In this paper, we focus on homology-modeling and more specifically, we review how it is perceived by the structural biology community and what can be done to impress on the experimentalists that it can be a valuable resource to them. We review the common practices and provide a set of guidelines for building better models. For that purpose, we introduce the H-factor, a new indicator for assessing the quality of homology models, mimicking the R-factor in X-ray crystallography. The methods for computing the H-factor is fully described and validated on a series of test cases. Conclusions We have developed a web service for computing the H-factor for models of a protein structure. This service is freely accessible at http://koehllab.genomecenter.ucdavis.edu/toolkit/h-factor. PMID:21291572
Probabilistic Usage of the Multi-Factor Interaction Model
Chamis, Christos C.
2008-01-01
A Multi-Factor Interaction Model (MFIM) is used to predict the insulating foam mass expulsion during the ascending of a space vehicle. The exponents in the MFIM are evaluated by an available approach which consists of least squares and an optimization algorithm. These results were subsequently used to probabilistically evaluate the effects of the uncertainties in each participating factor in the mass expulsion. The probabilistic results show that the surface temperature dominates at high probabilities and the pressure which causes the mass expulsion at low probabil
Results from a new Cocks-Ashby style porosity model
Barton, Nathan
2017-01-01
A new porosity evolution model is described, along with preliminary results. The formulation makes use of a Cocks-Ashby style treatment of porosity kinetics that includes rate dependent flow in the mechanics of porosity growth. The porosity model is implemented in a framework that allows for a variety of strength models to be used for the matrix material, including ones with significant changes in rate sensitivity as a function of strain rate. Results of the effect of changing strain rate sensitivity on porosity evolution are shown. The overall constitutive model update involves the coupled solution of a system of nonlinear equations.
K factor estimation in distribution transformers using linear regression models
Directory of Open Access Journals (Sweden)
Juan Miguel Astorga Gómez
2016-06-01
Full Text Available Background: Due to massive incorporation of electronic equipment to distribution systems, distribution transformers are subject to operation conditions other than the design ones, because of the circulation of harmonic currents. It is necessary to quantify the effect produced by these harmonic currents to determine the capacity of the transformer to withstand these new operating conditions. The K-factor is an indicator that estimates the ability of a transformer to withstand the thermal effects caused by harmonic currents. This article presents a linear regression model to estimate the value of the K-factor, from total current harmonic content obtained with low-cost equipment.Method: Two distribution transformers that feed different loads are studied variables, current total harmonic distortion factor K are recorded, and the regression model that best fits the data field is determined. To select the regression model the coefficient of determination R2 and the Akaike Information Criterion (AIC are used. With the selected model, the K-factor is estimated to actual operating conditions.Results: Once determined the model it was found that for both agricultural cargo and industrial mining, present harmonic content (THDi exceeds the values that these transformers can drive (average of 12.54% and minimum 8,90% in the case of agriculture and average value of 18.53% and a minimum of 6.80%, for industrial mining case.Conclusions: When estimating the K factor using polynomial models it was determined that studied transformers can not withstand the current total harmonic distortion of their current loads. The appropriate K factor for studied transformer should be 4; this allows transformers support the current total harmonic distortion of their respective loads.
Results of the Marine Ice Sheet Model Intercomparison Project, MISMIP
Directory of Open Access Journals (Sweden)
F. Pattyn
2012-05-01
Full Text Available Predictions of marine ice-sheet behaviour require models that are able to robustly simulate grounding line migration. We present results of an intercomparison exercise for marine ice-sheet models. Verification is effected by comparison with approximate analytical solutions for flux across the grounding line using simplified geometrical configurations (no lateral variations, no effects of lateral buttressing. Unique steady state grounding line positions exist for ice sheets on a downward sloping bed, while hysteresis occurs across an overdeepened bed, and stable steady state grounding line positions only occur on the downward-sloping sections. Models based on the shallow ice approximation, which does not resolve extensional stresses, do not reproduce the approximate analytical results unless appropriate parameterizations for ice flux are imposed at the grounding line. For extensional-stress resolving "shelfy stream" models, differences between model results were mainly due to the choice of spatial discretization. Moving grid methods were found to be the most accurate at capturing grounding line evolution, since they track the grounding line explicitly. Adaptive mesh refinement can further improve accuracy, including fixed grid models that generally perform poorly at coarse resolution. Fixed grid models, with nested grid representations of the grounding line, are able to generate accurate steady state positions, but can be inaccurate over transients. Only one full-Stokes model was included in the intercomparison, and consequently the accuracy of shelfy stream models as approximations of full-Stokes models remains to be determined in detail, especially during transients.
A model for sigma factor competition in bacterial cells.
Mauri, Marco; Klumpp, Stefan
2014-10-01
Sigma factors control global switches of the genetic expression program in bacteria. Different sigma factors compete for binding to a limited pool of RNA polymerase (RNAP) core enzymes, providing a mechanism for cross-talk between genes or gene classes via the sharing of expression machinery. To analyze the contribution of sigma factor competition to global changes in gene expression, we develop a theoretical model that describes binding between sigma factors and core RNAP, transcription, non-specific binding to DNA and the modulation of the availability of the molecular components. The model is validated by comparison with in vitro competition experiments, with which excellent agreement is found. Transcription is affected via the modulation of the concentrations of the different types of holoenzymes, so saturated promoters are only weakly affected by sigma factor competition. However, in case of overlapping promoters or promoters recognized by two types of sigma factors, we find that even saturated promoters are strongly affected. Active transcription effectively lowers the affinity between the sigma factor driving it and the core RNAP, resulting in complex cross-talk effects. Sigma factor competition is not strongly affected by non-specific binding of core RNAPs, sigma factors and holoenzymes to DNA. Finally, we analyze the role of increased core RNAP availability upon the shut-down of ribosomal RNA transcription during the stringent response. We find that passive up-regulation of alternative sigma-dependent transcription is not only possible, but also displays hypersensitivity based on the sigma factor competition. Our theoretical analysis thus provides support for a significant role of passive control during that global switch of the gene expression program.
Evaluation of methods for modeling transcription-factor sequence specificity
Weirauch, Matthew T.; Cote, Atina; Norel, Raquel; Annala, Matti; Zhao, Yue; Riley, Todd R.; Saez-Rodriguez, Julio; Cokelaer, Thomas; Vedenko, Anastasia; Talukder, Shaheynoor; Bussemaker, Harmen J.; Morris, Quaid D.; Bulyk, Martha L.; Stolovitzky, Gustavo
2013-01-01
Genomic analyses often involve scanning for potential transcription-factor (TF) binding sites using models of the sequence specificity of DNA binding proteins. Many approaches have been developed to model and learn a protein’s binding specificity, but these methods have not been systematically compared. Here we applied 26 such approaches to in vitro protein binding microarray data for 66 mouse TFs belonging to various families. For 9 TFs, we also scored the resulting motif models on in vivo data, and found that the best in vitro–derived motifs performed similarly to motifs derived from in vivo data. Our results indicate that simple models based on mononucleotide position weight matrices learned by the best methods perform similarly to more complex models for most TFs examined, but fall short in specific cases (<10%). In addition, the best-performing motifs typically have relatively low information content, consistent with widespread degeneracy in eukaryotic TF sequence preferences. PMID:23354101
Recent results in the NJL model with heavy quarks
Feldmann, T
1996-01-01
We investigate the interplay of chiral and heavy quark symmetries by using the NJL quark model. Heavy quarks with finite masses m(Q) as well as the limit m(Q) to infinity are studied. We found large corrections to the heavy mass scaling law for the pseudoscalar decay constant. The influence of external momenta on the shape parameters of the Isgur-Wise form factor is discussed.
The DSM-5 dimensional trait model and five-factor models of general personality.
Gore, Whitney L; Widiger, Thomas A
2013-08-01
The current study tests empirically the relationship of the dimensional trait model proposed for the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) with five-factor models of general personality. The DSM-5 maladaptive trait dimensional model proposal included 25 traits organized within five broad domains (i.e., negative affectivity, detachment, antagonism, disinhibition, and psychoticism). Consistent with the authors of the proposal, it was predicted that negative affectivity would align with five-factor model (FFM) neuroticism, detachment with FFM introversion, antagonism with FFM antagonism, disinhibition with low FFM conscientiousness and, contrary to the proposal; psychoticism would align with FFM openness. Three measures of alternative five-factor models of general personality were administered to 445 undergraduates along with the Personality Inventory for DSM-5. The results provided support for the hypothesis that all five domains of the DSM-5 dimensional trait model are maladaptive variants of general personality structure, including the domain of psychoticism.
Modeling individual subtests of the WAIS IV with multiple latent factors.
Directory of Open Access Journals (Sweden)
Dennis J McFarland
Full Text Available Performance on a cognitive test can be viewed either as measuring a unitary function or as reflecting the operation of multiple factors. Individual subtests in batteries designed to measure human abilities are commonly modeled as a single latent factor. Several latent factors are then used to model groups of subtests. However these latent factors are not independent as they are related through hierarchical or oblique structures. As a result, the simple structure of subtest performance results in complex latent factors. The present study used structural equation modeling to evaluate several multidimensional models of the Wechsler Adult Intelligence Scales-fourth edition (WAIS-IV subtests. Multidimensional models of subtest performance provided better model fit as compared to several previously proposed one dimensional models. These multidimensional models also generalized well to new samples of populations differing in age from that used to estimate the model parameters. Overall these results show that models that describe subtests as multidimensional functions of uncorrelated factors provided a better fit to the WAIS-IV correlations than models that describe subtests as one dimensional functions of correlated factors. There appears to be a trade-off in modeling subtests as one dimensional and modeling with homogeneous latent traits. More consideration should be given to models that include multiple uncorrelated latent factors as determinants of the performance on a given subtest. These results support the view that performance on any given cognitive test is potentially the result of multiple factors. Simple structure may be too simple.
Modeling individual subtests of the WAIS IV with multiple latent factors.
McFarland, Dennis J
2013-01-01
Performance on a cognitive test can be viewed either as measuring a unitary function or as reflecting the operation of multiple factors. Individual subtests in batteries designed to measure human abilities are commonly modeled as a single latent factor. Several latent factors are then used to model groups of subtests. However these latent factors are not independent as they are related through hierarchical or oblique structures. As a result, the simple structure of subtest performance results in complex latent factors. The present study used structural equation modeling to evaluate several multidimensional models of the Wechsler Adult Intelligence Scales-fourth edition (WAIS-IV) subtests. Multidimensional models of subtest performance provided better model fit as compared to several previously proposed one dimensional models. These multidimensional models also generalized well to new samples of populations differing in age from that used to estimate the model parameters. Overall these results show that models that describe subtests as multidimensional functions of uncorrelated factors provided a better fit to the WAIS-IV correlations than models that describe subtests as one dimensional functions of correlated factors. There appears to be a trade-off in modeling subtests as one dimensional and modeling with homogeneous latent traits. More consideration should be given to models that include multiple uncorrelated latent factors as determinants of the performance on a given subtest. These results support the view that performance on any given cognitive test is potentially the result of multiple factors. Simple structure may be too simple.
Probabilistic Multi-Factor Interaction Model for Complex Material Behavior
Abumeri, Galib H.; Chamis, Christos C.
2010-01-01
Complex material behavior is represented by a single equation of product form to account for interaction among the various factors. The factors are selected by the physics of the problem and the environment that the model is to represent. For example, different factors will be required for each to represent temperature, moisture, erosion, corrosion, etc. It is important that the equation represent the physics of the behavior in its entirety accurately. The Multi-Factor Interaction Model (MFIM) is used to evaluate the divot weight (foam weight ejected) from the external launch tanks. The multi-factor has sufficient degrees of freedom to evaluate a large number of factors that may contribute to the divot ejection. It also accommodates all interactions by its product form. Each factor has an exponent that satisfies only two points - the initial and final points. The exponent describes a monotonic path from the initial condition to the final. The exponent values are selected so that the described path makes sense in the absence of experimental data. In the present investigation, the data used were obtained by testing simulated specimens in launching conditions. Results show that the MFIM is an effective method of describing the divot weight ejected under the conditions investigated. The problem lies in how to represent the divot weight with a single equation. A unique solution to this problem is a multi-factor equation of product form. Each factor is of the following form (1 xi/xf)ei, where xi is the initial value, usually at ambient conditions, xf the final value, and ei the exponent that makes the curve represented unimodal that meets the initial and final values. The exponents are either evaluated by test data or by technical judgment. A minor disadvantage may be the selection of exponents in the absence of any empirical data. This form has been used successfully in describing the foam ejected in simulated space environmental conditions. Seven factors were required
Zero modes method and form factors in quantum integrable models
Directory of Open Access Journals (Sweden)
S. Pakuliak
2015-04-01
Full Text Available We study integrable models solvable by the nested algebraic Bethe ansatz and possessing GL(3-invariant R-matrix. Assuming that the monodromy matrix of the model can be expanded into series with respect to the inverse spectral parameter, we define zero modes of the monodromy matrix entries as the first nontrivial coefficients of this series. Using these zero modes we establish new relations between form factors of the elements of the monodromy matrix. We prove that all of them can be obtained from the form factor of a diagonal matrix element in special limits of Bethe parameters. As a result we obtain determinant representations for form factors of all the entries of the monodromy matrix.
Updated Results for the Wake Vortex Inverse Model
Robins, Robert E.; Lai, David Y.; Delisi, Donald P.; Mellman, George R.
2008-01-01
NorthWest Research Associates (NWRA) has developed an Inverse Model for inverting aircraft wake vortex data. The objective of the inverse modeling is to obtain estimates of the vortex circulation decay and crosswind vertical profiles, using time history measurements of the lateral and vertical position of aircraft vortices. The Inverse Model performs iterative forward model runs using estimates of vortex parameters, vertical crosswind profiles, and vortex circulation as a function of wake age. Iterations are performed until a user-defined criterion is satisfied. Outputs from an Inverse Model run are the best estimates of the time history of the vortex circulation derived from the observed data, the vertical crosswind profile, and several vortex parameters. The forward model, named SHRAPA, used in this inverse modeling is a modified version of the Shear-APA model, and it is described in Section 2 of this document. Details of the Inverse Model are presented in Section 3. The Inverse Model was applied to lidar-observed vortex data at three airports: FAA acquired data from San Francisco International Airport (SFO) and Denver International Airport (DEN), and NASA acquired data from Memphis International Airport (MEM). The results are compared with observed data. This Inverse Model validation is documented in Section 4. A summary is given in Section 5. A user's guide for the inverse wake vortex model is presented in a separate NorthWest Research Associates technical report (Lai and Delisi, 2007a).
Evidence for a General Factor Model of ADHD in Adults
Gibbins, Christopher; Toplak, Maggie E.; Flora, David B.; Weiss, Margaret D.; Tannock, Rosemary
2012-01-01
Objective: To examine factor structures of "Diagnostic and Statistical Manual of Mental Disorders" (4th ed.) symptoms of ADHD in adults. Method: Two sets of models were tested: (a) models with inattention and hyperactivity/impulsivity as separate but correlated latent constructs and (b) hierarchical general factor models with a general factor for…
Baryon octet electromagnetic form factors in a confining NJL model
Directory of Open Access Journals (Sweden)
Manuel E. Carrillo-Serrano
2016-08-01
Full Text Available Electromagnetic form factors of the baryon octet are studied using a Nambu–Jona-Lasinio model which utilizes the proper-time regularization scheme to simulate aspects of colour confinement. In addition, the model also incorporates corrections to the dressed quarks from vector meson correlations in the t-channel and the pion cloud. Comparison with recent chiral extrapolations of lattice QCD results shows a remarkable level of consistency. For the charge radii we find the surprising result that rEp
Risk Factor Assessment Branch staff have assessed indirectly the validity of parts of the Five-Factor Screener in two studies: NCI's Observing Protein and Energy (OPEN) Study and the Eating at America's Table Study (EATS). In both studies, multiple 24-hour recalls in conjunction with a measurement error model were used to assess validity.
Taking the Error Term of the Factor Model into Account: The Factor Score Predictor Interval
Beauducel, Andre
2013-01-01
The problem of factor score indeterminacy implies that the factor and the error scores cannot be completely disentangled in the factor model. It is therefore proposed to compute Harman's factor score predictor that contains an additive combination of factor and error variance. This additive combination is discussed in the framework of classical…
Generalised Chou-Yang model and recent results
Energy Technology Data Exchange (ETDEWEB)
Fazal-e-Aleem [International Centre for Theoretical Physics, Trieste (Italy); Rashid, H. [Punjab Univ., Lahore (Pakistan). Centre for High Energy Physics
1996-12-31
It is shown that most recent results of E710 and UA4/2 collaboration for the total cross section and {rho} together with earlier measurements give good agreement with measurements for the differential cross section at 546 and 1800 GeV within the framework of Generalised Chou-Yang model. These results are also compared with the predictions of other models. (author) 16 refs.
Life cycle Prognostic Model Development and Initial Application Results
Energy Technology Data Exchange (ETDEWEB)
Jeffries, Brien; Hines, Wesley; Nam, Alan; Sharp, Michael; Upadhyaya, Belle [The University of Tennessee, Knoxville (United States)
2014-08-15
In order to obtain more accurate Remaining Useful Life (RUL) estimates based on empirical modeling, a Lifecycle Prognostics algorithm was developed that integrates various prognostic models. These models can be categorized into three types based on the type of data they process. The application of multiple models takes advantage of the most useful information available as the system or component operates through its lifecycle. The Lifecycle Prognostics is applied to an impeller test bed, and the initial results serve as a proof of concept.
Competing Factor Models of Child and Adolescent Psychopathology.
Doyle, Mark M; Murphy, Jamie; Shevlin, Mark
2016-11-01
Co-occurring psychological disorders are highly prevalent among children and adolescents. To date, the most widely utilised factor model used to explain this co-occurrence is the two factor model of internalising and externalising (Achenbach 1966). Several competing models of general psychopathology have since been reported as alternatives, including a recent three factor model of Distress, Fear and Externalising Dimensions (Krueger 1999). Evidence for the three factor model suggests there are advantages to utilising a more complex model. Using the British Child and Adolescent Mental Health Survey 2004 data (B-CAMHS; N = 7997), confirmatory factor analysis was used to test competing factor structure models of child and adolescent psychopathology. The B-CAMHS was an epidemiological survey of children between the ages of 5 and 16 in Great Britain. Child psychological disorders were assessed using the Strength and Difficulties Questionnaire (Goodman 1997), and the Development and Wellbeing Assessment (Goodman et al. 2000). A range of covariates and risk variables including trauma, parent mental health and family functioning where subsequently utilised within a MIMIC model framework to predict each dimension of the 2 and three factor structure models. Two models demonstrated acceptable fit. The first complimented Achenbach's Internalising and Externalising structure. The three factor model was found to have highly comparable fit indices to the two factor model. The second order models did not accurately represent the data nor did an alternative three factor model of Internalising, Externalising and ADHD. The two factor and three factor MIMIC models observed unique profiles of risk for each dimension. The findings suggest that child and adolescent psychopathology may also be accurately conceptualised in terms of distress, fear and externalising dimensions. The MIMIC models demonstrated that the Distress and Fear dimensions have their own unique etiological profile of
The Five-Factor Model and Self-Determination Theory
DEFF Research Database (Denmark)
Olesen, Martin Hammershøj; Thomsen, Dorthe Kirkegaard; Schnieber, Anette
This study investigates conceptual overlap vs. distinction between individual differences in personality traits, i.e. the Five-Factor Model; and Self-determination Theory, i.e. general causality orientations. Twelve-hundred-and-eighty-seven freshmen (mean age 21.71; 64% women) completed electronic...... questionnaires of personality traits (NEO-FFI) and causality orientations (GCOS). To test whether covariance between traits and orientations could be attributed to shared or separate latent variables we conducted joint factor analyses. Results reveal that the Autonomy orientation can be distinguished from...
Comparing factor analytic models of the DSM-IV personality disorders.
Huprich, Steven K; Schmitt, Thomas A; Richard, David C S; Chelminski, Iwona; Zimmerman, Mark A
2010-01-01
There is little agreement about the latent factor structure of the Diagnostic and Statistical Manual of Mental Disorders (DSM) personality disorders (PDs). Factor analytic studies over the past 2 decades have yielded different results, in part reflecting differences in factor analytic technique, the measure used to assess the PDs, and the changing DSM criteria. In this study, we explore the latent factor structure of the DSM (4th ed.; IV) PDs in a sample of 1200 psychiatric outpatients evaluated with the Structured Interview for DSM-IV PDs (B. Pfohl, N. Blum, & M. Zimmerman, 1997). We first evaluated 2 a priori models of the PDs with confirmatory factor analysis (CFA), reflecting their inherent organization in the DSM-IV: a 3-factor model and a 10-factor model. Fit statistics did not suggest that these models yielded an adequate fit. We then evaluated the latent structure with exploratory factor analysis (EFA). Multiple solutions produced more statistically and theoretically reasonable results, as well as providing clinically useful findings. On the basis of fit statistics and theory, 3 models were evaluated further--the 4-, 5-, and 10-factor models. The 10-factor model, which did not resemble the 10-factor model of the CFA, was determined to be the strongest of all 3 models. Future research should use contemporary methods of evaluating factor analytic results in order to more thoroughly compare various factor solutions.
Common factors and the exchange rate: results from the Brazilian case
Directory of Open Access Journals (Sweden)
Wilson Rafael de Oliveira Felício
2014-03-01
Full Text Available This paper studies the usefulness of factor models in explaining the dynamics of the exchange rate Real / Dollar from January 1999 to August 2011. The paper verifies that the inclusion of factors embedded on the common movements of exchange rates of a set of countries significantly improves the in-sample and out-of-sample predictive power of the models comprising only macroeconomic fundamentals commonly used in the literature to forecast the exchange rate. The paper also links the information contained in the factors to global shocks like the demand for dollars - a "dollar effect", volatility and liquidity of global financial markets.
Factor Model Forecasts of Exchange Rates
Charles Engel; Nelson C. Mark; Kenneth D. West
2012-01-01
We construct factors from a cross section of exchange rates and use the idiosyncratic deviations from the factors to forecast. In a stylized data generating process, we show that such forecasts can be effective even if there is essentially no serial correlation in the univariate exchange rate processes. We apply the technique to a panel of bilateral U.S. dollar rates against 17 OECD countries. We forecast using factors, and using factors combined with any of fundamentals suggested by Taylor r...
Confirmatory Factor Analysis of WAIS-IV in a Clinical Sample: Examining a Bi-Factor Model
Directory of Open Access Journals (Sweden)
Rachel Collinson
2016-12-01
Full Text Available There have been a number of studies that have examined the factor structure of the Wechsler Adult Intelligence Scale IV (WAIS-IV using the standardization sample. In this study, we investigate its factor structure on a clinical neuropsychology sample of mixed aetiology. Correlated factor, higher-order and bi-factor models are all tested. Overall, the results suggest that the WAIS-IV will be suitable for use with this population.
Confirmatory Factor Analysis of WAIS-IV in a Clinical Sample: Examining a Bi-Factor Model
Rachel Collinson; Stephen Evans; Miranda Wheeler; Don Brechin; Jenna Moffitt; Geoff Hill; Steven Muncer
2016-01-01
There have been a number of studies that have examined the factor structure of the Wechsler Adult Intelligence Scale IV (WAIS-IV) using the standardization sample. In this study, we investigate its factor structure on a clinical neuropsychology sample of mixed aetiology. Correlated factor, higher-order and bi-factor models are all tested. Overall, the results suggest that the WAIS-IV will be suitable for use with this population.
Salekin, Randall T; Chen, Debra R; Sellbom, Martin; Lester, Whitney S; MacDougall, Emily
2014-07-01
The Levenson, Kiehl, and Fitzpatrick (1995) Self-Report Psychopathy Scale (LSRP) was introduced in the mid-1990s as a brief measure of psychopathy and has since gained considerable popularity. Despite its attractiveness as a brief psychopathy tool, the LSRP has received limited research regarding its factor structure and convergent and discriminant validity. The present study examined the construct validity of the LSRP, testing both its factor structure and the convergent and discriminant validity. Using a community sample of 1,257 undergraduates (869 females; 378 males), we tested whether a 1-, 2-, or 3-factor model best fit the data and examined the links between the resultant factor structures and external correlates. Confirmatory factor analysis (CFA) findings revealed a 3-factor model best matched the data, followed by an adequate-fitting original 2-factor model. Next, comparisons were made regarding the convergent and discriminant validity of the competing 2- and 3-factor models. Findings showed the LSRP traditional primary and secondary factors had meaningful relations with extratest variables such as neuroticism, stress tolerance, and lack of empathy. The 3-factor model showed particular problems with the Callousness scale. These findings underscore the importance of examining not only CFA fit statistics but also convergent and discriminant validity when testing factor structure models. The current findings suggest that the 2-factor model might still be the best way to interpret the LSRP. (c) 2014 APA, all rights reserved.
Calculating osmotic pressure according to nonelectrolyte Wilson nonrandom factor model.
Li, Hui; Zhan, Tingting; Zhan, Xiancheng; Wang, Xiaolan; Tan, Xiaoying; Guo, Yiping; Li, Chengrong
2014-08-01
Abstract The osmotic pressure of NaCl solutions was determined by the air humidity in equilibrium (AHE) method. The relationship between the osmotic pressure and the concentration was explored theoretically, and the osmotic pressure was calculated according to the nonelectrolyte Wilson nonrandom factor (N-Wilson-NRF) model from the concentration. The results indicate that the calculated osmotic pressure is comparable to the measured one.
Delta-tilde interpretation of standard linear mixed model results
DEFF Research Database (Denmark)
Brockhoff, Per Bruun; Amorim, Isabel de Sousa; Kuznetsova, Alexandra
2016-01-01
effects relative to the residual error and to choose the proper effect size measure. For multi-attribute bar plots of F-statistics this amounts, in balanced settings, to a simple transformation of the bar heights to get them transformed into depicting what can be seen as approximately the average pairwise...... for factors with differences in number of levels. For mixed models, where in general the relevant error terms for the fixed effects are not the pure residual error, it is suggested to base the d-prime-like interpretation on the residual error. The methods are illustrated on a multifactorial sensory profile...... inherently challenging effect size measure estimates in ANOVA settings....
Meteorological Uncertainty of atmospheric Dispersion model results (MUD)
DEFF Research Database (Denmark)
Havskov Sørensen, Jens; Amstrup, Bjarne; Feddersen, Henrik
The MUD project addresses assessment of uncertainties of atmospheric dispersion model predictions, as well as optimum presentation to decision makers. Previously, it has not been possible to estimate such uncertainties quantitatively, but merely to calculate the 'most likely' dispersion scenario...... of the meteorological model results. These uncertainties stem from e.g. limits in meteorological obser-vations used to initialise meteorological forecast series. By perturbing the initial state of an NWP model run in agreement with the available observa-tional data, an ensemble of meteorological forecasts is produced....... However, recent developments in numerical weather prediction (NWP) include probabilistic forecasting techniques, which can be utilised also for atmospheric dispersion models. The ensemble statistical methods developed and applied to NWP models aim at describing the inherent uncertainties...
Meteorological Uncertainty of atmospheric Dispersion model results (MUD)
DEFF Research Database (Denmark)
Havskov Sørensen, Jens; Amstrup, Bjarne; Feddersen, Henrik
The MUD project addresses assessment of uncertainties of atmospheric dispersion model predictions, as well as possibilities for optimum presentation to decision makers. Previously, it has not been possible to estimate such uncertainties quantitatively, but merely to calculate the ‘most likely...... uncertainties of the meteorological model results. These uncertainties stem from e.g. limits in meteorological observations used to initialise meteorological forecast series. By perturbing e.g. the initial state of an NWP model run in agreement with the available observational data, an ensemble......’ dispersion scenario. However, recent developments in numerical weather prediction (NWP) include probabilistic forecasting techniques, which can be utilised also for long-range atmospheric dispersion models. The ensemble statistical methods developed and applied to NWP models aim at describing the inherent...
Mathematical Existence Results for the Doi-Edwards Polymer Model
Chupin, Laurent
2017-01-01
In this paper, we present some mathematical results on the Doi-Edwards model describing the dynamics of flexible polymers in melts and concentrated solutions. This model, developed in the late 1970s, has been used and extensively tested in modeling and simulation of polymer flows. From a mathematical point of view, the Doi-Edwards model consists in a strong coupling between the Navier-Stokes equations and a highly nonlinear constitutive law. The aim of this article is to provide a rigorous proof of the well-posedness of the Doi-Edwards model, namely that it has a unique regular solution. We also prove, which is generally much more difficult for flows of viscoelastic type, that the solution is global in time in the two dimensional case, without any restriction on the smallness of the data.
Modeling Results for the ITER Cryogenic Fore Pump
Zhang, Dongsheng
The work presented here is the analysis and modeling of the ITER-Cryogenic Fore Pump (CFP), also called Cryogenic Viscous Compressor (CVC). Unlike common cryopumps that are usually used to create and maintain vacuum, the cryogenic fore pump is designed for ITER to collect and compress hydrogen isotopes during the regeneration process of the torus cryopumps. Different from common cryopumps, the ITER-CFP works in the viscous flow regime. As a result, both adsorption boundary conditions and transport phenomena contribute unique features to the pump performance. In this report, the physical mechanisms of cryopumping are studied, especially the diffusion-adsorption process and these are coupled with the standard equations of species, momentum and energy balance, as well as the equation of state. Numerical models are developed, which include highly coupled non-linear conservation equations of species, momentum, and energy and equation of state. Thermal and kinetic properties are treated as functions of temperature, pressure, and composition of the gas fluid mixture. To solve such a set of equations, a novel numerical technique, identified as the Group-Member numerical technique is proposed. This document presents three numerical models: a transient model, a steady state model, and a hemisphere (or molecular flow) model. The first two models are developed based on analysis of the raw experimental data while the third model is developed as a preliminary study. The modeling results are compared with available experiment data for verification. The models can be used for cryopump design, and can also benefit problems, such as loss of vacuum in a cryomodule or cryogenic desublimation. The scientific and engineering investigation being done here builds connections between Mechanical Engineering and other disciplines, such as Chemical Engineering, Physics, and Chemistry.
Quasi Maximum Likelihood Analysis of High Dimensional Constrained Factor Models
Li, Kunpeng; Li,Qi; Lu, Lina
2016-01-01
Factor models have been widely used in practice. However, an undesirable feature of a high dimensional factor model is that the model has too many parameters. An effective way to address this issue, proposed in a seminar work by Tsai and Tsay (2010), is to decompose the loadings matrix by a high-dimensional known matrix multiplying with a low-dimensional unknown matrix, which Tsai and Tsay (2010) name constrained factor models. This paper investigates the estimation and inferential theory ...
Comparison of NASCAP modelling results with lumped circuit analysis
Stang, D. B.; Purvis, C. K.
1980-01-01
Engineering design tools that can be used to predict the development of absolute and differential potentials by realistic spacecraft under geomagnetic substorm conditions are described. Two types of analyses are in use: (1) the NASCAP code, which computes quasistatic charging of geometrically complex objects with multiple surface materials in three dimensions; (2) lumped element equivalent circuit models that are used for analyses of particular spacecraft. The equivalent circuit models require very little computation time, however, they cannot account for effects, such as the formation of potential barriers, that are inherently multidimensional. Steady state potentials of structure and insulation are compared with those resulting from the equivalent circuit model.
The East model: recent results and new progresses
Faggionato, Alessandra; Roberto, Cyril; Toninelli, Cristina
2012-01-01
The East model is a particular one dimensional interacting particle system in which certain transitions are forbidden according to some constraints depending on the configuration of the system. As such it has received particular attention in the physics literature as a special case of a more general class of systems referred to as kinetically constrained models, which play a key role in explaining some features of the dynamics of glasses. In this paper we give an extensive overview of recent rigorous results concerning the equilibrium and non-equilibrium dynamics of the East model together with some new improvements.
Constraining hybrid inflation models with WMAP three-year results
Cardoso, A
2006-01-01
We reconsider the original model of quadratic hybrid inflation in light of the WMAP three-year results and study the possibility of obtaining a spectral index of primordial density perturbations, $n_s$, smaller than one from this model. The original hybrid inflation model naturally predicts $n_s\\geq1$ in the false vacuum dominated regime but it is also possible to have $n_s<1$ when the quadratic term dominates. We therefore investigate whether there is also an intermediate regime compatible with the latest constraints, where the scalar field value during the last 50 e-folds of inflation is less than the Planck scale.
Recent MEG Results and Predictive SO(10) Models
Fukuyama, Takeshi
2011-01-01
Recent MEG results of a search for the lepton flavor violating (LFV) muon decay, $\\mu \\to e \\gamma$, show 3 events as the best value for the number of signals in the maximally likelihood fit. Although this result is still far from the evidence/discovery in statistical point of view, it might be a sign of a certain new physics beyond the Standard Model. As has been well-known, supersymmetric (SUSY) models can generate the $\\mu \\to e \\gamma$ decay rate within the search reach of the MEG experiment. A certain class of SUSY grand unified theory (GUT) models such as the minimal SUSY SO(10) model (we call this class of models "predictive SO(10) models") can unambiguously determine fermion Yukawa coupling matrices, in particular, the neutrino Dirac Yukawa matrix. Based on the universal boundary conditions for soft SUSY breaking parameters at the GUT scale, we calculate the rate of the $\\mu \\to e \\gamma$ process by using the completely determined Dirac Yukawa matrix in two examples of predictive SO(10) models. If we ...
Summary of FY15 results of benchmark modeling activities
Energy Technology Data Exchange (ETDEWEB)
Arguello, J. Guadalupe [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
2015-08-01
Sandia is participating in the third phase of an is a contributing partner to a U.S.-German "Joint Project" entitled "Comparison of current constitutive models and simulation procedures on the basis of model calculations of the thermo-mechanical behavior and healing of rock salt." The first goal of the project is to check the ability of numerical modeling tools to correctly describe the relevant deformation phenomena in rock salt under various influences. Achieving this goal will lead to increased confidence in the results of numerical simulations related to the secure storage of radioactive wastes in rock salt, thereby enhancing the acceptance of the results. These results may ultimately be used to make various assertions regarding both the stability analysis of an underground repository in salt, during the operating phase, and the long-term integrity of the geological barrier against the release of harmful substances into the biosphere, in the post-operating phase.
Modeling Individual Subtests of the WAIS IV with Multiple Latent Factors
2013-01-01
Performance on a cognitive test can be viewed either as measuring a unitary function or as reflecting the operation of multiple factors. Individual subtests in batteries designed to measure human abilities are commonly modeled as a single latent factor. Several latent factors are then used to model groups of subtests. However these latent factors are not independent as they are related through hierarchical or oblique structures. As a result, the simple structure of subtest performance results...
Liquidity and Fama-French Three-Factor Model
Institute of Scientific and Technical Information of China (English)
陈政
2012-01-01
The Fama-French three-factor model was proposed to explain the expected return. In this paper,the author takes advantage of the recent data from NYSE, AMEX and NASDAQ stocks to examine whether the Fama-French three-factor model can explain the expected return well on the basis of reviewing the importance of liquidity and criticizing the Fama-French three-factor model. It turns out that the three-factor model can still reflect the factor in asset pricing to a certain degree.
The FIRO model of family therapy: implications of factor analysis.
Hafner, R J; Ross, M W
1989-11-01
Schutz's FIRO model contains three main elements: inclusion, control, and affection. It is used widely in mental health research and practice, but has received little empirical validation. The present study is based on factor analysis of the resources to FIRO questionnaire of 120 normal couples and 191 couples who were attending a clinic for marital/psychiatric problems. Results confirmed the validity of the FIRO model for women only. The differences between the sexes reflected a considerable degree of sex-role stereotyping, the clinical implications of which are discussed.
Standard Model physics results from ATLAS and CMS
Dordevic, Milos
2015-01-01
The most recent results of Standard Model physics studies in proton-proton collisions at 7 TeV and 8 TeV center-of-mass energy based on data recorded by ATLAS and CMS detectors during the LHC Run I are reviewed. This overview includes studies of vector boson production cross section and properties, results on V+jets production with light and heavy flavours, latest VBS and VBF results, measurement of diboson production with an emphasis on ATGC and QTGC searches, as well as results on inclusive jet cross sections with strong coupling constant measurement and PDF constraints. The outlined results are compared to the prediction of the Standard Model.
Stegeman, Alwin
2016-01-01
In the common factor model the observed data is conceptually split into a common covariance producing part and an uncorrelated unique part. The common factor model is fitted to the data itself and a new method is introduced for the simultaneous estimation of loadings, unique variances, factor scores
Stegeman, Alwin
In the common factor model the observed data is conceptually split into a common covariance producing part and an uncorrelated unique part. The common factor model is fitted to the data itself and a new method is introduced for the simultaneous estimation of loadings, unique variances, factor
Blumenthal, James A.; Smith, Patrick J.; Durheim, Michael; Mabe, Stephanie; Emery, Charles F.; Martinu, Tereza; Diaz, Philip T.; Babyak, Michael; Welty-Wolf, Karen; Palmer, Scott
2015-01-01
Objective To examine the prognostic value of select biobehavioral factors in patients with chronic obstructive pulmonary disease (COPD) in a secondary analysis of participants from the INSPIRE-II trial. Methods Three hundred twenty six outpatients with COPD underwent assessments of pulmonary function, physical activity, body mass index, inflammation, pulmonary symptoms, depression, and pulmonary quality of life, and were followed for up to 5.4 years for subsequent clinical events. The prognostic value of each biobehavioral factor, considered individually and combined, also was examined in the context of existing Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2011 risk stratification. Results Sixty-nine individuals experienced a hospitalization or died over a mean follow-up time period of 2.4 (interquartile range = 1.6) years. GOLD classification was associated with an increased risk of clinical events (HR = 2.72 [95% CI 1.63, 4.54], per stage); Six Minute Walk (HR = 0.50 [0.34, 0.73] per 500 feet), total steps (HR = 0.82 [0.71, 0.94] per 1,000 steps), hsC-reactive protein (HR = 1.44 [1.01, 2.06] per 4.5 mg/L), depression (HR = 1.12 [1.01, 1.25] per 4 points), and pulmonary quality of life (HR = 1.73 [1.14, 2.63] per 25 points) were each predictive over and above the GOLD assessment. However, only GOLD group and Six Minute Walk were predictive of all-cause mortality and COPD hospitalization when all biobehavioral variables were included together in a multivariable model. Conclusion Biobehavioral factors provide added prognostic information over and above measures of COPD severity in predicting adverse events in patients with COPD. PMID:26780299
Relationship Marketing results: proposition of a cognitive mapping model
Directory of Open Access Journals (Sweden)
Iná Futino Barreto
2015-12-01
Full Text Available Objective - This research sought to develop a cognitive model that expresses how marketing professionals understand the relationship between the constructs that define relationship marketing (RM. It also tried to understand, using the obtained model, how objectives in this field are achieved. Design/methodology/approach – Through cognitive mapping, we traced 35 individual mental maps, highlighting how each respondent understands the interactions between RM elements. Based on the views of these individuals, we established an aggregate mental map. Theoretical foundation – The topic is based on a literature review that explores the RM concept and its main elements. Based on this review, we listed eleven main constructs. Findings – We established an aggregate mental map that represents the RM structural model. Model analysis identified that CLV is understood as the final result of RM. We also observed that the impact of most of the RM elements on CLV is brokered by loyalty. Personalization and quality, on the other hand, proved to be process input elements, and are the ones that most strongly impact others. Finally, we highlight that elements that punish customers are much less effective than elements that benefit them. Contributions - The model was able to insert core elements of RM, but absent from most formal models: CLV and customization. The analysis allowed us to understand the interactions between the RM elements and how the end result of RM (CLV is formed. This understanding improves knowledge on the subject and helps guide, assess and correct actions.
Studying Effective Factors on Corporate Entrepreneurship: Representing a Model
Directory of Open Access Journals (Sweden)
Maryam Soleimani
2013-02-01
Full Text Available Development and advancement of current organizations depends on Corporate Entrepreneurship (CE and its anticipants considerably. Therefore purpose of conducting this survey is to study effective factors on corporate entrepreneurship (personal characteristics of entrepreneurship, human resource practices, organizational culture and employees' satisfaction. This survey was conducted using descriptive-field methodology. Statistical population included managers and experts of Hexa Consulting Engineers Company (Tehran/Iran and the sample consisted of forty seven of them. Questionnaire was tool of data collection. Data was collected in cross-sectional form in July-August 2011. Descriptive and inferential (spearman correlation statistics methods were used for data analysis. According to results, there is a positive significant relationship among all factors (personal characteristics of entrepreneurship, human resource practices, organizational culture and employees' satisfaction and corporate entrepreneurship. In other words, the proposed variables as effective factors on corporate entrepreneurship were confirmed in conceptual model of survey.
Chronic gastritis rat model and role of inducing factors
Institute of Scientific and Technical Information of China (English)
Zun Xiang; Jian-Min Si; Huai-De Huang
2004-01-01
AIM: To establish an experimental animal model of chronic gastritis in a short term and to investigate the effects of several potential inflammation-inducing factors on rat gastric mucosa.METHODS: Twenty-four healthy, male SD rats were treated with intragastric administration of 600 mL/L alcohol, 20mmol/L sodium deoxycholate and 0.5 g/L ammonia (factor A), forage containing low levels of vitamins (factor B), and/or indomethacin (factor C), according to an L8(27)orthogonal design. After 12 wk, gastric antral and body mucosae were pathologically examined.RESULTS: Chronic gastritis model was successfully induced in rats treated with factor A for 12 wk. After the treatment of animals, the gastric mucosal inflammation was significantly different from that in controls, and the number of pyloric glands at antrum and parietal cells at body were obviously reduced (P＜0.01). Indomethacin induced gastritis but without atrophy, and short-term vitamin deficiency failed to induce chronic gastritis and gastric atrophy, In addition,indomethacin and vitamin deficiency had no synergistic effect in inducing gastritis with the factor A. No atypical hyperplasia and intestinal metaplasia in the gastric antrum and body were observed in all rats studied.CONCLUSION: Combined intragastric administration of 600 mL/L alcohol, 20 mmol/L sodium deoxycholate and 0.5 g/L ammonia induces chronic gastritis and gastric atrophy in rats. Indomethacin induces chronic gastritis only.The long-term roles of these factors in gastric inflammation and carcinogenesis need to be further elucidated.
Marginal production in the Gulf of Mexico - II. Model results
Energy Technology Data Exchange (ETDEWEB)
Kaiser, Mark J.; Yu, Yunke [Center for Energy Studies, Louisiana State University, Baton Rouge, LA 70803 (United States)
2010-08-15
In the second part of this two-part article on marginal production in the Gulf of Mexico, we estimate the number of committed assets in water depth less than 1000 ft that are expected to be marginal over a 60-year time horizon. We compute the expected quantity and value of the production and gross revenue streams of the gulf's committed asset inventory circa. January 2007 using a probabilistic model framework. Cumulative hydrocarbon production from the producing inventory is estimated to be 1056 MMbbl oil and 13.3 Tcf gas. Marginal production from the committed asset inventory is expected to contribute 4.1% of total oil production and 5.4% of gas production. A meta-evaluation procedure is adapted to present the results of sensitivity analysis. Model results are discussed along with a description of the model framework and limitations of the analysis. (author)
DEFF Research Database (Denmark)
Rosenbaum, Ralph K.; Hauschild, Michael Zwicky; Bachmann, Till M.;
Over the last two years, the developers of seven toxicity characterization models collaborated to carry out a comprehensive model comparison as part of the UNEP/SETAC Life Cycle Initiative. The models in this evaluation included CalTOX, IMPACT 2002, USES-LCA, BETR, EDIP, WATSON, and Eco......Sense. This paper summarizes and draws lessons from this model evaluation process. The main objectives of this effort were to 1) identify specific sources of differences in model results, 2) define common and indispensable model components, and 3) use the selected models to build a “scientific consensus” model...
Exact results for car accidents in a traffic model
Huang, Ding-wei
1998-07-01
Within the framework of a recent model for car accidents on single-lane highway traffic, we study analytically the probability of the occurrence of car accidents. Exact results are obtained. Various scaling behaviours are observed. The linear dependence of the occurrence of car accidents on density is understood as the dominance of a single velocity in the distribution.
First results from the International Urban Energy Balance Model Comparison: Model Complexity
Blackett, M.; Grimmond, S.; Best, M.
2009-04-01
A great variety of urban energy balance models has been developed. These vary in complexity from simple schemes that represent the city as a slab, through those which model various facets (i.e. road, walls and roof) to more complex urban forms (including street canyons with intersections) and features (such as vegetation cover and anthropogenic heat fluxes). Some schemes also incorporate detailed representations of momentum and energy fluxes distributed throughout various layers of the urban canopy layer. The models each differ in the parameters they require to describe the site and the in demands they make on computational processing power. Many of these models have been evaluated using observational datasets but to date, no controlled comparisons have been conducted. Urban surface energy balance models provide a means to predict the energy exchange processes which influence factors such as urban temperature, humidity, atmospheric stability and winds. These all need to be modelled accurately to capture features such as the urban heat island effect and to provide key information for dispersion and air quality modelling. A comparison of the various models available will assist in improving current and future models and will assist in formulating research priorities for future observational campaigns within urban areas. In this presentation we will summarise the initial results of this international urban energy balance model comparison. In particular, the relative performance of the models involved will be compared based on their degree of complexity. These results will inform us on ways in which we can improve the modelling of air quality within, and climate impacts of, global megacities. The methodology employed in conducting this comparison followed that used in PILPS (the Project for Intercomparison of Land-Surface Parameterization Schemes) which is also endorsed by the GEWEX Global Land Atmosphere System Study (GLASS) panel. In all cases, models were run
Heteroscedastic one-factor models and marginal maximum likelihood estimation
Hessen, D.J.; Dolan, C.V.
2009-01-01
In the present paper, a general class of heteroscedastic one-factor models is considered. In these models, the residual variances of the observed scores are explicitly modelled as parametric functions of the one-dimensional factor score. A marginal maximum likelihood procedure for parameter estimati
Modeling Results For the ITER Cryogenic Fore Pump. Final Report
Energy Technology Data Exchange (ETDEWEB)
Pfotenhauer, John M. [University of Wisconsin, Madison, WI (United States); Zhang, Dongsheng [University of Wisconsin, Madison, WI (United States)
2014-03-31
A numerical model characterizing the operation of a cryogenic fore-pump (CFP) for ITER has been developed at the University of Wisconsin – Madison during the period from March 15, 2011 through June 30, 2014. The purpose of the ITER-CFP is to separate hydrogen isotopes from helium gas, both making up the exhaust components from the ITER reactor. The model explicitly determines the amount of hydrogen that is captured by the supercritical-helium-cooled pump as a function of the inlet temperature of the supercritical helium, its flow rate, and the inlet conditions of the hydrogen gas flow. Furthermore the model computes the location and amount of hydrogen captured in the pump as a function of time. Throughout the model’s development, and as a calibration check for its results, it has been extensively compared with the measurements of a CFP prototype tested at Oak Ridge National Lab. The results of the model demonstrate that the quantity of captured hydrogen is very sensitive to the inlet temperature of the helium coolant on the outside of the cryopump. Furthermore, the model can be utilized to refine those tests, and suggests methods that could be incorporated in the testing to enhance the usefulness of the measured data.
Assessment of Galileo modal test results for mathematical model verification
Trubert, M.
1984-01-01
The modal test program for the Galileo Spacecraft was completed at the Jet Propulsion Laboratory in the summer of 1983. The multiple sine dwell method was used for the baseline test. The Galileo Spacecraft is a rather complex 2433 kg structure made of a central core on which seven major appendages representing 30 percent of the total mass are attached, resulting in a high modal density structure. The test revealed a strong nonlinearity in several major modes. This nonlinearity discovered in the course of the test necessitated running additional tests at the unusually high response levels of up to about 21 g. The high levels of response were required to obtain a model verification valid at the level of loads for which the spacecraft was designed. Because of the high modal density and the nonlinearity, correlation between the dynamic mathematical model and the test results becomes a difficult task. Significant changes in the pre-test analytical model are necessary to establish confidence in the upgraded analytical model used for the final load verification. This verification, using a test verified model, is required by NASA to fly the Galileo Spacecraft on the Shuttle/Centaur launch vehicle in 1986.
Photovoltaic Grid-Connected Modeling and Characterization Based on Experimental Results
Humada, Ali M.; Hojabri, Mojgan; Sulaiman, Mohd Herwan Bin; Hamada, Hussein M.; Ahmed, Mushtaq N.
2016-01-01
A grid-connected photovoltaic (PV) system operates under fluctuated weather condition has been modeled and characterized based on specific test bed. A mathematical model of a small-scale PV system has been developed mainly for residential usage, and the potential results have been simulated. The proposed PV model based on three PV parameters, which are the photocurrent, IL, the reverse diode saturation current, Io, the ideality factor of diode, n. Accuracy of the proposed model and its parameters evaluated based on different benchmarks. The results showed that the proposed model fitting the experimental results with high accuracy compare to the other models, as well as the I-V characteristic curve. The results of this study can be considered valuable in terms of the installation of a grid-connected PV system in fluctuated climatic conditions. PMID:27035575
Model correction factor method for system analysis
DEFF Research Database (Denmark)
Ditlevsen, Ove Dalager; Johannesen, Johannes M.
2000-01-01
severallocally most central points exist without there being a simple geometric definition of the corresponding failuremodes such as is the case for collapse mechanisms in rigid plastic hinge models for frame structures. Taking as simplifiedidealized model a model of similarity with the elaborate model...... but with clearly defined failure modes, the MCFM can bestarted from each idealized single mode limit state in turn to identify a locally most central point on the elaborate limitstate surface. Typically this procedure leads to a fewer number of locally most central failure points on the elaboratelimit state...... surface than existing in the idealized model....
A statistical evaluation of factors influencing aerial survey results on brown bears
US Fish and Wildlife Service, Department of the Interior — This report is a statistical evaluation of factors influencing aerial survey results on Brown Bears. The purpose of this study was to provide a statistical...
Modeling vertical loads in pools resulting from fluid injection. [BWR
Energy Technology Data Exchange (ETDEWEB)
Lai, W.; McCauley, E.W.
1978-06-15
Table-top model experiments were performed to investigate pressure suppression pool dynamics effects due to a postulated loss-of-coolant accident (LOCA) for the Peachbottom Mark I boiling water reactor containment system. The results guided subsequent conduct of experiments in the /sup 1///sub 5/-scale facility and provided new insight into the vertical load function (VLF). Model experiments show an oscillatory VLF with the download typically double-spiked followed by a more gradual sinusoidal upload. The load function contains a high frequency oscillation superimposed on a low frequency one; evidence from measurements indicates that the oscillations are initiated by fluid dynamics phenomena.
Principal component and factor analytic models in international sire evaluation
Directory of Open Access Journals (Sweden)
Jakobsen Jette
2011-09-01
Full Text Available Abstract Background Interbull is a non-profit organization that provides internationally comparable breeding values for globalized dairy cattle breeding programmes. Due to different trait definitions and models for genetic evaluation between countries, each biological trait is treated as a different trait in each of the participating countries. This yields a genetic covariance matrix of dimension equal to the number of countries which typically involves high genetic correlations between countries. This gives rise to several problems such as over-parameterized models and increased sampling variances, if genetic (covariance matrices are considered to be unstructured. Methods Principal component (PC and factor analytic (FA models allow highly parsimonious representations of the (covariance matrix compared to the standard multi-trait model and have, therefore, attracted considerable interest for their potential to ease the burden of the estimation process for multiple-trait across country evaluation (MACE. This study evaluated the utility of PC and FA models to estimate variance components and to predict breeding values for MACE for protein yield. This was tested using a dataset comprising Holstein bull evaluations obtained in 2007 from 25 countries. Results In total, 19 principal components or nine factors were needed to explain the genetic variation in the test dataset. Estimates of the genetic parameters under the optimal fit were almost identical for the two approaches. Furthermore, the results were in a good agreement with those obtained from the full rank model and with those provided by Interbull. The estimation time was shortest for models fitting the optimal number of parameters and prolonged when under- or over-parameterized models were applied. Correlations between estimated breeding values (EBV from the PC19 and PC25 were unity. With few exceptions, correlations between EBV obtained using FA and PC approaches under the optimal fit were
Supervision in Factor Models Using a Large Number of Predictors
DEFF Research Database (Denmark)
Boldrini, Lorenzo; Hillebrand, Eric Tobias
In this paper we investigate the forecasting performance of a particular factor model (FM) in which the factors are extracted from a large number of predictors. We use a semi-parametric state-space representation of the FM in which the forecast objective, as well as the factors, is included.......g. a standard dynamic factor model with separate forecast and state equations....... in the state vector. The factors are informed of the forecast target (supervised) through the state equation dynamics. We propose a way to assess the contribution of the forecast objective on the extracted factors that exploits the Kalman filter recursions. We forecast one target at a time based...
Gaussian and Lognormal Models of Hurricane Gust Factors
Merceret, Frank
2009-01-01
A document describes a tool that predicts the likelihood of land-falling tropical storms and hurricanes exceeding specified peak speeds, given the mean wind speed at various heights of up to 500 feet (150 meters) above ground level. Empirical models to calculate mean and standard deviation of the gust factor as a function of height and mean wind speed were developed in Excel based on data from previous hurricanes. Separate models were developed for Gaussian and offset lognormal distributions for the gust factor. Rather than forecasting a single, specific peak wind speed, this tool provides a probability of exceeding a specified value. This probability is provided as a function of height, allowing it to be applied at a height appropriate for tall structures. The user inputs the mean wind speed, height, and operational threshold. The tool produces the probability from each model that the given threshold will be exceeded. This application does have its limits. They were tested only in tropical storm conditions associated with the periphery of hurricanes. Winds of similar speed produced by non-tropical system may have different turbulence dynamics and stability, which may change those winds statistical characteristics. These models were developed along the Central Florida seacoast, and their results may not accurately extrapolate to inland areas, or even to coastal sites that are different from those used to build the models. Although this tool cannot be generalized for use in different environments, its methodology could be applied to those locations to develop a similar tool tuned to local conditions.
The Five-Factor Model and Self-Determination Theory
DEFF Research Database (Denmark)
Olesen, Martin Hammershøj; Thomsen, Dorthe Kirkegaard; Schnieber, Anette;
questionnaires of personality traits (NEO-FFI) and causality orientations (GCOS). To test whether covariance between traits and orientations could be attributed to shared or separate latent variables we conducted joint factor analyses. Results reveal that the Autonomy orientation can be distinguished from......This study investigates conceptual overlap vs. distinction between individual differences in personality traits, i.e. the Five-Factor Model; and Self-determination Theory, i.e. general causality orientations. Twelve-hundred-and-eighty-seven freshmen (mean age 21.71; 64% women) completed electronic...... related personality traits. The Control orientation shares a latent variable with reversed Agreeableness. The Impersonal orientation shows both overlapping and distinct features with Neuroticism. Results are discussed in relation to an integrative understanding of traits and orientations....
Initial CGE Model Results Summary Exogenous and Endogenous Variables Tests
Energy Technology Data Exchange (ETDEWEB)
Edwards, Brian Keith [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Boero, Riccardo [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rivera, Michael Kelly [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-08-07
The following discussion presents initial results of tests of the most recent version of the National Infrastructure Simulation and Analysis Center Dynamic Computable General Equilibrium (CGE) model developed by Los Alamos National Laboratory (LANL). The intent of this is to test and assess the model’s behavioral properties. The test evaluated whether the predicted impacts are reasonable from a qualitative perspective. This issue is whether the predicted change, be it an increase or decrease in other model variables, is consistent with prior economic intuition and expectations about the predicted change. One of the purposes of this effort is to determine whether model changes are needed in order to improve its behavior qualitatively and quantitatively.
Simulating lightning into the RAMS model: implementation and preliminary results
Directory of Open Access Journals (Sweden)
S. Federico
2014-05-01
Full Text Available This paper shows the results of a tailored version of a previously published methodology, designed to simulate lightning activity, implemented into the Regional Atmospheric Modeling System (RAMS. The method gives the flash density at the resolution of the RAMS grid-scale allowing for a detailed analysis of the evolution of simulated lightning activity. The system is applied in detail to two case studies occurred over the Lazio Region, in Central Italy. Simulations are compared with the lightning activity detected by the LINET network. The cases refer to two thunderstorms of different intensity. Results show that the model predicts reasonably well both cases and that the lightning activity is well reproduced especially for the most intense case. However, there are errors in timing and positioning of the convection, whose magnitude depends on the case study, which mirrors in timing and positioning errors of the lightning distribution. To assess objectively the performance of the methodology, standard scores are presented for four additional case studies. Scores show the ability of the methodology to simulate the daily lightning activity for different spatial scales and for two different minimum thresholds of flash number density. The performance decreases at finer spatial scales and for higher thresholds. The comparison of simulated and observed lighting activity is an immediate and powerful tool to assess the model ability to reproduce the intensity and the evolution of the convection. This shows the importance of the use of computationally efficient lightning schemes, such as the one described in this paper, in forecast models.
Modeling air quality over China: Results from the Panda project
Katinka Petersen, Anna; Bouarar, Idir; Brasseur, Guy; Granier, Claire; Xie, Ying; Wang, Lili; Wang, Xuemei
2015-04-01
China faces strong air pollution problems related to rapid economic development in the past decade and increasing demand for energy. Air quality monitoring stations often report high levels of particle matter and ozone all over the country. Knowing its long-term health impacts, air pollution became then a pressing problem not only in China but also in other Asian countries. The PANDA project is a result of cooperation between scientists from Europe and China who joined their efforts for a better understanding of the processes controlling air pollution in China, improve methods for monitoring air quality and elaborate indicators in support of European and Chinese policies. A modeling system of air pollution is being setup within the PANDA project and include advanced global (MACC, EMEP) and regional (WRF-Chem, EMEP) meteorological and chemical models to analyze and monitor air quality in China. The poster describes the accomplishments obtained within the first year of the project. Model simulations for January and July 2010 are evaluated with satellite measurements (SCIAMACHY NO2 and MOPITT CO) and in-situ data (O3, CO, NOx, PM10 and PM2.5) observed at several surface stations in China. Using the WRF-Chem model, we investigate the sensitivity of the model performance to emissions (MACCity, HTAPv2), horizontal resolution (60km, 20km) and choice of initial and boundary conditions.
Factors Affecting the Result of Matches in the One Day Format of Cricket
Directory of Open Access Journals (Sweden)
Ananda Bandulasiri
2016-01-01
Full Text Available Factors contributing to winning games are imperative, as the ultimate objective in a game is victory. The aim of this study was to identify the factors that characterize the game of cricket, and to investigate the factors that truly influence the result of a game using the data collected from the Champions Trophy cricket tournament. According to the results, this cricket tournament can be characterized using the factors of batting, bowling, and decision-making. Further investigation suggests that the rank of the team and the number of runs they score have the most significant influence on the result of games. As far as the effectiveness of assigning bowlers is concerned, the Australian team has done a fabulous job compared to the rest of the teams. (original abstract
A model for equivalent axle load factors
Amorim, Sara I.R.; Pais, Jorge; Vale, Aline C.; Minhoto, Manuel
2014-01-01
Most design methods for road pavements require the design traffic, based on the transformation of the traffic spectrum, to be calculated into a number of equivalent passages of a standard axle using the equivalent axle load factors. Generally, these factors only consider the type of axle (single, tandem or tridem), but they do not consider the type of wheel on the axles, i.e., single or dual wheel. The type of wheel has an important influence on the calculation of the design traffic. The exis...
Exact results for the one dimensional asymmetric exclusion model
Derrida, B.; Evans, M. R.; Hakim, V.; Pasquier, V.
1993-11-01
The asymmetric exclusion model describes a system of particles hopping in a preferred direction with hard core repulsion. These particles can be thought of as charged particles in a field, as steps of an interface, as cars in a queue. Several exact results concerning the steady state of this system have been obtained recently. The solution consists of representing the weights of the configurations in the steady state as products of non-commuting matrices.
Exact results for the one dimensional asymmetric exclusion model
Energy Technology Data Exchange (ETDEWEB)
Derrida, B.; Evans, M.R.; Pasquier, V. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Service de Physique Theorique; Hakim, V. [Ecole Normale Superieure, 75 - Paris (France)
1993-12-31
The asymmetric exclusion model describes a system of particles hopping in a preferred direction with hard core repulsion. These particles can be thought of as charged particles in a field, as steps of an interface, as cars in a queue. Several exact results concerning the steady state of this system have been obtained recently. The solution consists of representing the weights of the configurations in the steady state as products of non-commuting matrices. (author).
APPLYING LOGISTIC REGRESSION MODEL TO THE EXAMINATION RESULTS DATA
Directory of Open Access Journals (Sweden)
Goutam Saha
2011-01-01
Full Text Available The binary logistic regression model is used to analyze the school examination results(scores of 1002 students. The analysis is performed on the basis of the independent variables viz.gender, medium of instruction, type of schools, category of schools, board of examinations andlocation of schools, where scores or marks are assumed to be dependent variables. The odds ratioanalysis compares the scores obtained in two examinations viz. matriculation and highersecondary.
Analytical results for a three-phase traffic model.
Huang, Ding-wei
2003-10-01
We study analytically a cellular automaton model, which is able to present three different traffic phases on a homogeneous highway. The characteristics displayed in the fundamental diagram can be well discerned by analyzing the evolution of density configurations. Analytical expressions for the traffic flow and shock speed are obtained. The synchronized flow in the intermediate-density region is the result of aggressive driving scheme and determined mainly by the stochastic noise.
Numerical modelling of radon-222 entry into houses: An outline of techniques and results
DEFF Research Database (Denmark)
Andersen, C.E.
2001-01-01
Numerical modelling is a powerful tool for studies of soil gas and radon-222 entry into houses. It is the purpose of this paper to review some main techniques and results. In the past, modelling has focused on Darcy flow of soil gas (driven by indoor–outdoor pressure differences) and combined...... diffusive and advective transport of radon. Models of different complexity have been used. The simpler ones are finite-difference models with one or two spatial dimensions. The more complex models allow for full three-dimensional and time dependency. Advanced features include: soil heterogeneity, anisotropy......, fractures, moisture, non-uniform soil temperature, non-Darcy flow of gas, and flow caused by changes in the atmospheric pressure. Numerical models can be used to estimate the importance of specific factors for radon entry. Models are also helpful when results obtained in special laboratory or test structure...
Feigelson, Heather Spencer; James, Ted A; Single, Richard M; Onitilo, Adedayo A; Aiello Bowles, Erin J; Barney, Tom; Bakerman, Jordan E; McCahill, Laurence E
2013-05-01
Several previous studies have reported conflicting data on recent trends in use of initial total mastectomy (TM); the factors that contribute to TM variation are not entirely clear. Using a multi-institution database, we analyzed how practice, patient, and tumor characteristics contributed to variation in TM for invasive breast cancer. We collected detailed clinical and pathologic data about breast cancer diagnosis, initial, and subsequent breast cancer operations performed on all female patients from 4 participating institutions from 2003 to 2008. We limited this analysis to 2,384 incident cases of invasive breast cancer, stages I to III, and excluded patients with clinical indications for mastectomy. Predictors of initial TM were identified with univariate analyses and random effects multivariable logistic regression models. Initial TM was performed on 397 (16.7%) eligible patients. Use of preoperative MRI more than doubled the rate of TM (odds ratio [OR] = 2.44; 95% CI, 1.58-3.77; p < 0.0001). Increasing tumor size, high nuclear grade, and age were also associated with increased rates of initial TM. Differences by age and ethnicity were observed, and significant variation in the frequency of TM was seen at the individual surgeon level (p < 0.001). Our results were similar when restricted to tumors <20 mm. We identified factors associated with initial TM, including preoperative MRI and individual surgeon, that contribute to the current debate about variation in use of TM for the management of breast cancer. Additional evaluation of patient understanding of surgical options and outcomes in breast cancer and the impact of the surgeon provider is warranted. Copyright © 2013 American College of Surgeons. Published by Elsevier Inc. All rights reserved.
Challenges in validating model results for first year ice
Melsom, Arne; Eastwood, Steinar; Xie, Jiping; Aaboe, Signe; Bertino, Laurent
2017-04-01
In order to assess the quality of model results for the distribution of first year ice, a comparison with a product based on observations from satellite-borne instruments has been performed. Such a comparison is not straightforward due to the contrasting algorithms that are used in the model product and the remote sensing product. The implementation of the validation is discussed in light of the differences between this set of products, and validation results are presented. The model product is the daily updated 10-day forecast from the Arctic Monitoring and Forecasting Centre in CMEMS. The forecasts are produced with the assimilative ocean prediction system TOPAZ. Presently, observations of sea ice concentration and sea ice drift are introduced in the assimilation step, but data for sea ice thickness and ice age (or roughness) are not included. The model computes the age of the ice by recording and updating the time passed after ice formation as sea ice grows and deteriorates as it is advected inside the model domain. Ice that is younger than 365 days is classified as first year ice. The fraction of first-year ice is recorded as a tracer in each grid cell. The Ocean and Sea Ice Thematic Assembly Centre in CMEMS redistributes a daily product from the EUMETSAT OSI SAF of gridded sea ice conditions which include "ice type", a representation of the separation of regions between those infested by first year ice, and those infested by multi-year ice. The ice type is parameterized based on data for the gradient ratio GR(19,37) from SSMIS observations, and from the ASCAT backscatter parameter. This product also includes information on ambiguity in the processing of the remote sensing data, and the product's confidence level, which have a strong seasonal dependency.
van der Gaag, Mark; Cuijpers, Anke; Hoffman, Tonko; Remijsen, Mila; Hijman, Ron; de Haan, Lieuwe; van Meijel, Berno; van Harten, Peter N.; Valmaggia, Lucia; de Hert, Marc; Wiersma, Durk
2006-01-01
Objective: The aim of this study was to test the goodness-of-fit of all previously published five-factor models of the Positive and Negative Syndrome Scale (PANSS). Methods: We used confirmatory factor analysis (CFA) with a large data set (N = 5769). Results: The different subsamples were tested for
Results of Satellite Brightness Modeling Using Kringing Optimized Interpolation
Weeden, C.; Hejduk, M.
At the 2005 AMOS conference, Kriging Optimized Interpolation (KOI) was presented as a tool to model satellite brightness as a function of phase angle and solar declination angle (J.M Okada and M.D. Hejduk). Since November 2005, this method has been used to support the tasking algorithm for all optical sensors in the Space Surveillance Network (SSN). The satellite brightness maps generated by the KOI program are compared to each sensor's ability to detect an object as a function of the brightness of the background sky and angular rate of the object. This will determine if the sensor can technically detect an object based on an explicit calculation of the object's probability of detection. In addition, recent upgrades at Ground-Based Electro Optical Deep Space Surveillance Sites (GEODSS) sites have increased the amount and quality of brightness data collected and therefore available for analysis. This in turn has provided enough data to study the modeling process in more detail in order to obtain the most accurate brightness prediction of satellites. Analysis of two years of brightness data gathered from optical sensors and modeled via KOI solutions are outlined in this paper. By comparison, geo-stationary objects (GEO) were tracked less than non-GEO objects but had higher density tracking in phase angle due to artifices of scheduling. A statistically-significant fit to a deterministic model was possible less than half the time in both GEO and non-GEO tracks, showing that a stochastic model must often be used alone to produce brightness results, but such results are nonetheless serviceable. Within the Kriging solution, the exponential variogram model was the most frequently employed in both GEO and non-GEO tracks, indicating that monotonic brightness variation with both phase and solar declination angle is common and testifying to the suitability to the application of regionalized variable theory to this particular problem. Finally, the average nugget value, or
Titan Chemistry: Results From A Global Climate Model
Wilson, Eric; West, R. A.; Friedson, A. J.; Oyafuso, F.
2008-09-01
We present results from a 3-dimesional global climate model of Titan's atmosphere and surface. This model, a modified version of NCAR's CAM-3 (Community Atmosphere Model), has been optimized for analysis of Titan's lower atmosphere and surface. With the inclusion of forcing from Saturn's gravitational tides, interaction from the surface, transfer of longwave and shortwave radiation, and parameterization of haze properties, constrained by Cassini observations, a dynamical field is generated, which serves to advect 14 long-lived species. The concentrations of these chemical tracers are also affected by 82 chemical reactions and the photolysis of 21 species, based on the Wilson and Atreya (2004) model, that provide sources and sinks for the advected species along with 23 additional non-advected radicals. In addition, the chemical contribution to haze conversion is parameterized along with the microphysical processes that serve to distribute haze opacity throughout the atmosphere. References Wilson, E.H. and S.K. Atreya, J. Geophys. Res., 109, E06002, 2004.
Why Does a Kronecker Model Result in Misleading Capacity Estimates?
Raghavan, Vasanthan; Sayeed, Akbar M
2008-01-01
Many recent works that study the performance of multi-input multi-output (MIMO) systems in practice assume a Kronecker model where the variances of the channel entries, upon decomposition on to the transmit and the receive eigen-bases, admit a separable form. Measurement campaigns, however, show that the Kronecker model results in poor estimates for capacity. Motivated by these observations, a channel model that does not impose a separable structure has been recently proposed and shown to fit the capacity of measured channels better. In this work, we show that this recently proposed modeling framework can be viewed as a natural consequence of channel decomposition on to its canonical coordinates, the transmit and/or the receive eigen-bases. Using tools from random matrix theory, we then establish the theoretical basis behind the Kronecker mismatch at the low- and the high-SNR extremes: 1) Sparsity of the dominant statistical degrees of freedom (DoF) in the true channel at the low-SNR extreme, and 2) Non-regul...
Najafipour, Hamid; Malek Mohammadi, Tayebeh; Rahim, Foad; Haghdoost, Ali Akbar; Shadkam, Mitra; Afshari, Mahdi
2013-01-01
Objectives. This study aimed to determine the association between some oral health status as a risk factor for cardiac diseases and other cardiovascular disease (CVD) risk factors in a sample of Iranian population in 2011. Methods. The study recruited 5900 inhabitants who aged 15-75 years old of Kerman city through a population based cluster sampling. Having collected informed consent, participants were interviewed for CVD risk factors. Some oral health indicators such as DMFT, Gingival Inflammation index, and Community Periodontal Index were assessed. The association between oral health indices and CVD risk factors was tested using multivariate regression models. Results. The mean age of participants was 33.5 years, and 45.1% were male. Moderate gingival inflammation was observed in 67.6% of participants. Presence of sub- or supragingival calculus was more common (90%) in participants. Older age (RR from 2.7 to 3.88), cigarette smoking (RR = 1.49), and high blood glucose (RR = 1.41) showed an increased risk for oral diseases after adjustment for different covariates including established CVD risk factors. Conclusion. The study results showed an increase in periodontal diseases in the presence of some CVD risk factors. Therefore there may be a bilateral but independent association for both conditions and common risk factor approach preventive program is highly recommended.
Some Results on Optimal Dividend Problem in Two Risk Models
Directory of Open Access Journals (Sweden)
Shuaiqi Zhang
2010-12-01
Full Text Available The compound Poisson risk model and the compound Poisson risk model perturbed by diffusion are considered in the presence of a dividend barrier with solvency constraints. Moreover, it extends the known result due to [1]. Ref. [1] finds the optimal dividend policy is of a barrier type for a jump-diffusion model with exponentially distributed jumps. In this paper, it turns out that there can be two different solutions depending on the model’s parameters. Furthermore, an interesting result is given: the proportional transaction cost has no effect on the dividend barrier. The objective of the corporation is to maximize the cumulative expected discounted dividends payout with solvency constraints before the time of ruin. It is well known that under some reasonable assumptions, optimal dividend strategy is a barrier strategy, i.e., there is a level b_{1}(b_{2} so that whenever surplus goes above the level b_{1}(b_{2}, the excess is paid out as dividends. However, the optimal level b_{1}(b_{2} may be unacceptably low from a solvency point of view. Therefore, some constraints should imposed on an insurance company such as to pay out dividends unless the surplus has reached a level b^{1}_{c}>b_{1}(b^2_{c}>b_{2} . We show that in this case a barrier strategy at b^{1}_{c}(b^2_{c} is optimal.
Modeling results for the ITER cryogenic fore pump
Zhang, D. S.; Miller, F. K.; Pfotenhauer, J. M.
2014-01-01
The cryogenic fore pump (CFP) is designed for ITER to collect and compress hydrogen isotopes during the regeneration process of torus cryopumps. Different from common cryopumps, the ITER-CFP works in the viscous flow regime. As a result, both adsorption boundary conditions and transport phenomena contribute unique features to the pump performance. In this report, the physical mechanisms of cryopumping are studied, especially the diffusion-adsorption process and these are coupled with standard equations of species, momentum and energy balance, as well as the equation of state. Numerical models are developed, which include highly coupled non-linear conservation equations of species, momentum and energy and equation of state. Thermal and kinetic properties are treated as functions of temperature, pressure, and composition. To solve such a set of equations, a novel numerical technique, identified as the Group-Member numerical technique is proposed. It is presented here a 1D numerical model. The results include comparison with the experimental data of pure hydrogen flow and a prediction for hydrogen flow with trace helium. An advanced 2D model and detailed explanation of the Group-Member technique are to be presented in following papers.
Nikiforuk, K K; Rotenberg, V S; Rashidov, N R; Laneev, A I
1986-01-01
Factor analysis was carried out of sleep structure and results of complex psychodiagnostic study in 35 subjects. Seven orthogonal factors were singled out. It is shown that alarm level is connected with fast sleep general presentation; the system of psychological defences is linked with the fast sleep in the second cycle; the self-control in alert state and the transfer from alertness to sleep are interrelated, and duration of the first and last sleep cycles are reciprocally connected.
Stochastic contribution to the growth factor in the LCDM model
Energy Technology Data Exchange (ETDEWEB)
Ribeiro, A. L.B.; Andrade, A. P.A.; Letelier, P. S.
2009-01-01
We study the effect of noise on the evolution of the growth factor of density perturbations in the context of the LCDM model. Stochasticity is introduced as a Wiener process amplified by an intensity parameter alpha. By comparing the evolution of deterministic and stochastic cases for different values of alpha we estimate the intensity level necessary to make noise relevant for cosmological tests based on large-scale structure data. Our results indicate that the presence of random forces underlying the fluid description can lead to significant deviations from the nonstochastic solution at late times for alpha>0.001.
Assessment of the five-factor model of personality.
Widiger, T A; Trull, T J
1997-04-01
The five-factor model (FFM) of personality is obtaining construct validation, recognition, and practical consideration across a broad domain of fields, including clinical psychology, industrial-organizational psychology, and health psychology. As a result, an array of instruments have been developed and existing instruments are being modified to assess the FFM. In this article, we present an overview and critique of five such instruments (the Goldberg Big Five Markers, the revised NEO Personality Inventory, the Interpersonal Adjective Scales-Big Five, the Personality Psychopathology-Five, and the Hogan Personality Inventory), focusing in particular on their representation of the lexical FFM and their practical application.
Positive Orientation and the Five-Factor Model
Directory of Open Access Journals (Sweden)
Miciuk Łukasz Roland
2016-04-01
Full Text Available The aim of the present study was to investigate the relationship between positive orientation (PO defined as a basic predisposition to perceive and evaluate positive aspects of life, the future and oneself and the Five-Factor Model of personality (FFM. Hypotheses postulated positive correlations between PO and extraversion, conscientiousness, agreeableness and openness; a negative correlation was predicted between PO and neuroticism. Two hundred Polish students completed the following measures: SES (Self-Esteem Scale, Rosenberg, SWLS (The Satisfaction with Life Scale; Diener, Emmons, Larson & Griffin, LOT-R (The Life Orientation Test - Revised; Scheier, Carver & Bridges and NEOFFI (NEO Five Factor Inventory, Costa & McCrae. The results confirmed correlations between PO and extraversion, conscientiousness, and neuroticism; correlations with openness and agreeableness were not supported. According to canonical correlations, PO shows a clear affinity to the FFM.
SR-Site groundwater flow modelling methodology, setup and results
Energy Technology Data Exchange (ETDEWEB)
Selroos, Jan-Olof (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Follin, Sven (SF GeoLogic AB, Taeby (Sweden))
2010-12-15
As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken three groundwater flow modelling studies. These are performed within the SR-Site project and represent time periods with different climate conditions. The simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. Three time periods are addressed; the Excavation and operational phases, the Initial period of temperate climate after closure, and the Remaining part of the reference glacial cycle. The present report is a synthesis of the background reports describing the modelling methodology, setup, and results. It is the primary reference for the conclusions drawn in a SR-Site specific context concerning groundwater flow during the three climate periods. These conclusions are not necessarily provided explicitly in the background reports, but are based on the results provided in these reports. The main results and comparisons presented in the present report are summarised in the SR-Site Main report.
Geochemical controls on shale groundwaters: Results of reaction path modeling
Energy Technology Data Exchange (ETDEWEB)
Von Damm, K.L.; VandenBrook, A.J.
1989-03-01
The EQ3NR/EQ6 geochemical modeling code was used to simulate the reaction of several shale mineralogies with different groundwater compositions in order to elucidate changes that may occur in both the groundwater compositions, and rock mineralogies and compositions under conditions which may be encountered in a high-level radioactive waste repository. Shales with primarily illitic or smectitic compositions were the focus of this study. The reactions were run at the ambient temperatures of the groundwaters and to temperatures as high as 250/degree/C, the approximate temperature maximum expected in a repository. All modeling assumed that equilibrium was achieved and treated the rock and water assemblage as a closed system. Graphite was used as a proxy mineral for organic matter in the shales. The results show that the presence of even a very small amount of reducing mineral has a large influence on the redox state of the groundwaters, and that either pyrite or graphite provides essentially the same results, with slight differences in dissolved C, Fe and S concentrations. The thermodynamic data base is inadequate at the present time to fully evaluate the speciation of dissolved carbon, due to the paucity of thermodynamic data for organic compounds. In the illitic cases the groundwaters resulting from interaction at elevated temperatures are acid, while the smectitic cases remain alkaline, although the final equilibrium mineral assemblages are quite similar. 10 refs., 8 figs., 15 tabs.
Energy Technology Data Exchange (ETDEWEB)
Ajami, N K; Duan, Q; Gao, X; Sorooshian, S
2005-04-11
This paper examines several multi-model combination techniques: the Simple Multi-model Average (SMA), the Multi-Model Super Ensemble (MMSE), Modified Multi-Model Super Ensemble (M3SE) and the Weighted Average Method (WAM). These model combination techniques were evaluated using the results from the Distributed Model Intercomparison Project (DMIP), an international project sponsored by the National Weather Service (NWS) Office of Hydrologic Development (OHD). All of the multi-model combination results were obtained using uncalibrated DMIP model outputs and were compared against the best uncalibrated as well as the best calibrated individual model results. The purpose of this study is to understand how different combination techniques affect the skill levels of the multi-model predictions. This study revealed that the multi-model predictions obtained from uncalibrated single model predictions are generally better than any single member model predictions, even the best calibrated single model predictions. Furthermore, more sophisticated multi-model combination techniques that incorporated bias correction steps work better than simple multi-model average predictions or multi-model predictions without bias correction.
A comparison of the VAR model and the PC factor model in forecasting inflation in Montenegro
Directory of Open Access Journals (Sweden)
Lipovina-Božović Milena
2013-01-01
Full Text Available Montenegro started using the euro in 2002 and regained independence in 2006. Its main economic partners are European countries, yet inflation movements in Montenegro do not coincide with consumer price fluctuations in the eurozone. Trying to develop a useful forecasting model for Montenegrin inflation, we compare the results of a three-variable vector autoregression (VAR model, and a principle component (PC factor model starting with twelve variables. The estimation period is January 2001 to December 2012, and the control months are the first six months of 2013. The results show that in forecasting inflation, despite a high level of Montenegrin economic dependence on international developments, more reliable forecasts are achieved with the use of additional information on a larger number of factors, which includes domestic economic activity.
The comparison of measured impedance of the bladder tissue with the computational modeling results
Directory of Open Access Journals (Sweden)
ahmad keshtkar
2015-11-01
Full Text Available Introduction: The electrical impedance spectroscopy technique can be used to measure the electrical impedance of the human bladder tissue, for differentiating pathological changes in the urothelium. Methods: In this study, the electrical impedance spectroscopy technique and then, a numerical technique, finite element analysis (FEA were used to model the electrical properties of this tissue to predict the impedance spectrum of the normal and malignant areas of this organ. Results: After determining and comparing the modeled data with the experimental results, it is believed that there are some factors that may affect the measurement results. Thus, the effect of inflammation, edema, changes in the applied pressure over the probe and the distensible property of the bladder tissue were considered. Furthermore, the current distribution inside the human bladder tissue was modeled in normal and malignant cases using the FEA. This model results showed that very little of the current actually flows through the urothelium and much of the injected current flows through the connective tissue beneath the urothelium. Conclusion: The results of the models do not explain the measurements results. In conclusion, there are many factors, which may account for discrepancies between the measured and modeled data.
VNIR spectral modeling of Mars analogue rocks: first results
Pompilio, L.; Roush, T.; Pedrazzi, G.; Sgavetti, M.
Knowledge regarding the surface composition of Mars and other bodies of the inner solar system is fundamental to understanding of their origin, evolution, and internal structures. Technological improvements of remote sensors and associated implications for planetary studies have encouraged increased laboratory and field spectroscopy research to model the spectral behavior of terrestrial analogues for planetary surfaces. This approach has proven useful during Martian surface and orbital missions, and petrologic studies of Martian SNC meteorites. Thermal emission data were used to suggest two lithologies occurring on Mars surface: basalt with abundant plagioclase and clinopyroxene and andesite, dominated by plagioclase and volcanic glass [1,2]. Weathered basalt has been suggested as an alternative to the andesite interpretation [3,4]. Orbital VNIR spectral imaging data also suggest the crust is dominantly basaltic, chiefly feldspar and pyroxene [5,6]. A few outcrops of ancient crust have higher concentrations of olivine and low-Ca pyroxene, and have been interpreted as cumulates [6]. Based upon these orbital observations future lander/rover missions can be expected to encounter particulate soils, rocks, and rock outcrops. Approaches to qualitative and quantitative analysis of remotely-acquired spectra have been successfully used to infer the presence and abundance of minerals and to discover compositionally associated spectral trends [7-9]. Both empirical [10] and mathematical [e.g. 11-13] methods have been applied, typically with full compositional knowledge, to chiefly particulate samples and as a result cannot be considered as objective techniques for predicting the compositional information, especially for understanding the spectral behavior of rocks. Extending the compositional modeling efforts to include more rocks and developing objective criteria in the modeling are the next required steps. This is the focus of the present investigation. We present results of
Analysis of effect factors-based stochastic network planning model
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
Looking at all the indeterminate factors as a whole and regarding activity durations as independent random variables,the traditional stochastic network planning models ignore the inevitable relationship and dependence among activity durations when more than one activity is possibly affected by the same indeterminate factors.On this basis of analysis of indeterminate effect factors of durations,the effect factors-based stochastic network planning (EFBSNP) model is proposed,which emphasizes on the effects of not only logistic and organizational relationships,but also the dependent relationships,due to indeterminate factors among activity durations on the project period.By virtue of indeterminate factor analysis the model extracts and describes the quantitatively indeterminate effect factors,and then takes into account the indeterminate factors effect schedule by using the Monte Carlo simulation technique.The method is flexible enough to deal with effect factors and is coincident with practice.A software has been developed to simplify the model-based calculation,in VisualStudio.NET language.Finally,a case study is included to demonstrate the applicability of the proposed model and comparison is made with some advantages over the existing models.
ITER CS Model Coil and CS Insert Test Results
Energy Technology Data Exchange (ETDEWEB)
Martovetsky, N; Michael, P; Minervina, J; Radovinsky, A; Takayasu, M; Thome, R; Ando, T; Isono, T; Kato, T; Nakajima, H; Nishijima, G; Nunoya, Y; Sugimoto, M; Takahashi, Y; Tsuji, H; Bessette, D; Okuno, K; Ricci, M
2000-09-07
The Inner and Outer modules of the Central Solenoid Model Coil (CSMC) were built by US and Japanese home teams in collaboration with European and Russian teams to demonstrate the feasibility of a superconducting Central Solenoid for ITER and other large tokamak reactors. The CSMC mass is about 120 t, OD is about 3.6 m and the stored energy is 640 MJ at 46 kA and peak field of 13 T. Testing of the CSMC and the CS Insert took place at Japan Atomic Energy Research Institute (JAERI) from mid March until mid August 2000. This paper presents the main results of the tests performed.
Results of the benchmark for blade structural models, part A
DEFF Research Database (Denmark)
Lekou, D.J.; Chortis, D.; Belen Fariñas, A.;
2013-01-01
Task 2.2 of the InnWind.Eu project. The benchmark is based on the reference wind turbine and the reference blade provided by DTU [1]. "Structural Concept developers/modelers" of WP2 were provided with the necessary input for a comparison numerical simulation run, upon definition of the reference blade......A benchmark on structural design methods for blades was performed within the InnWind.Eu project under WP2 “Lightweight Rotor” Task 2.2 “Lightweight structural design”. The present document is describes the results of the comparison simulation runs that were performed by the partners involved within...
Preliminary results of steel containment vessel model test
Energy Technology Data Exchange (ETDEWEB)
Luk, V.K.; Hessheimer, M.F. [Sandia National Labs., Albuquerque, NM (United States); Matsumoto, T.; Komine, K.; Arai, S. [Nuclear Power Engineering Corp., Tokyo (Japan); Costello, J.F. [Nuclear Regulatory Commission, Washington, DC (United States)
1998-04-01
A high pressure test of a mixed-scaled model (1:10 in geometry and 1:4 in shell thickness) of a steel containment vessel (SCV), representing an improved boiling water reactor (BWR) Mark II containment, was conducted on December 11--12, 1996 at Sandia National Laboratories. This paper describes the preliminary results of the high pressure test. In addition, the preliminary post-test measurement data and the preliminary comparison of test data with pretest analysis predictions are also presented.
Energy Technology Data Exchange (ETDEWEB)
Ajami, N; Duan, Q; Gao, X; Sorooshian, S
2006-05-08
This paper examines several multi-model combination techniques: the Simple Multimodel Average (SMA), the Multi-Model Super Ensemble (MMSE), Modified Multi-Model Super Ensemble (M3SE) and the Weighted Average Method (WAM). These model combination techniques were evaluated using the results from the Distributed Model Intercomparison Project (DMIP), an international project sponsored by the National Weather Service (NWS) Office of Hydrologic Development (OHD). All of the multi-model combination results were obtained using uncalibrated DMIP model outputs and were compared against the best uncalibrated as well as the best calibrated individual model results. The purpose of this study is to understand how different combination techniques affect the skill levels of the multi-model predictions. This study revealed that the multi-model predictions obtained from uncalibrated single model predictions are generally better than any single member model predictions, even the best calibrated single model predictions. Furthermore, more sophisticated multi-model combination techniques that incorporated bias correction steps work better than simple multi-model average predictions or multi-model predictions without bias correction.
Institute of Scientific and Technical Information of China (English)
Thomas Walcher; Bernhard Otto Boehm; Wolfgang Kratzer; Mark Martin Haenle; Martina Kron; Birgit Hay; Richard Andrew Mason; Alexa Friederike Alice von Schmiesing; Armin Imhof; Wolfgang Koenig; Peter Kern
2005-01-01
AIM: To investigate the prevalence, risk factors, and selection of the study population for cholecystolithiasis in an urban population in Germany, in relation to our own findings and to the results in the international literature.METHODS: A total of 2 147 persons (1 111 females,age 42.8±12.7 years; 1 036 males, age 42.3±13.1 years)participating in an investigation on the prevalence of Echinococcus multilocularis were studied for risk factors and prevalence of gallbladder stone disease.Risk factors were assessed by means of a standardized interview and calculation of body mass index (BMI). A diagnostic ultrasound examination of the gallbladder was performed. Data were analyzed by multiple logistic regression, using the SAS statistical software package.RESULTS: Gallbladder stones were detected in 171study participants (8.0%, n = 2 147). Risk factors for the development of gallbladder stone disease included age, sex, BMI, and positive family history. In a separate analysis of female study participants, pregnancy (yes/no)and number of pregnancies did not exert any influence.CONCLUSION: Findings of the present study confirm that age, female sex, BMI, and positive family history are risk factors for the development of gallbladder stone disease. Pregnancy and the number of pregnancies,however, could not be shown to be risk factors. There seem to be no differences in the respective prevalence for gallbladder stone disease in urban and rural populations.
Impact Flash Physics: Modeling and Comparisons With Experimental Results
Rainey, E.; Stickle, A. M.; Ernst, C. M.; Schultz, P. H.; Mehta, N. L.; Brown, R. C.; Swaminathan, P. K.; Michaelis, C. H.; Erlandson, R. E.
2015-12-01
horizontal. High-speed radiometer measurements were made of the time-dependent impact flash at wavelengths of 350-1100 nm. We will present comparisons between these measurements and the output of APL's model. The results of this validation allow us to determine basic relationships between observed optical signatures and impact conditions.
Gu, Fei; Preacher, Kristopher J; Wu, Wei; Yung, Yiu-Fai
2014-01-01
Although the state space approach for estimating multilevel regression models has been well established for decades in the time series literature, it does not receive much attention from educational and psychological researchers. In this article, we (a) introduce the state space approach for estimating multilevel regression models and (b) extend the state space approach for estimating multilevel factor models. A brief outline of the state space formulation is provided and then state space forms for univariate and multivariate multilevel regression models, and a multilevel confirmatory factor model, are illustrated. The utility of the state space approach is demonstrated with either a simulated or real example for each multilevel model. It is concluded that the results from the state space approach are essentially identical to those from specialized multilevel regression modeling and structural equation modeling software. More importantly, the state space approach offers researchers a computationally more efficient alternative to fit multilevel regression models with a large number of Level 1 units within each Level 2 unit or a large number of observations on each subject in a longitudinal study.
Convergence results for a coarsening model using global linearization
Gallay, T; Gallay, Th.
2002-01-01
We study a coarsening model describing the dynamics of interfaces in the one-dimensional Allen-Cahn equation. Given a partition of the real line into intervals of length greater than one, the model consists in constantly eliminating the shortest interval of the partition by merging it with its two neighbors. We show that the mean-field equation for the time-dependent distribution of interval lengths can be explicitly solved using a global linearization transformation. This allows us to derive rigorous results on the long-time asymptotics of the solutions. If the average length of the intervals is finite, we prove that all distributions approach a uniquely determined self-similar solution. We also obtain global stability results for the family of self-similar profiles which correspond to distributions with infinite expectation. eliminating the shortest interval of the partition by merging it with its two neighbors. We show that the mean-field equation for the time-dependent distribution of interval lengths can...
Compressible Turbulent Channel Flows: DNS Results and Modeling
Huang, P. G.; Coleman, G. N.; Bradshaw, P.; Rai, Man Mohan (Technical Monitor)
1994-01-01
The present paper addresses some topical issues in modeling compressible turbulent shear flows. The work is based on direct numerical simulation of two supersonic fully developed channel flows between very cold isothermal walls. Detailed decomposition and analysis of terms appearing in the momentum and energy equations are presented. The simulation results are used to provide insights into differences between conventional time-and Favre-averaging of the mean-flow and turbulent quantities. Study of the turbulence energy budget for the two cases shows that the compressibility effects due to turbulent density and pressure fluctuations are insignificant. In particular, the dilatational dissipation and the mean product of the pressure and dilatation fluctuations are very small, contrary to the results of simulations for sheared homogeneous compressible turbulence and to recent proposals for models for general compressible turbulent flows. This provides a possible explanation of why the Van Driest density-weighted transformation is so successful in correlating compressible boundary layer data. Finally, it is found that the DNS data do not support the strong Reynolds analogy. A more general representation of the analogy is analysed and shown to match the DNS data very well.
Seepage-Based Factor of Safety Analysis Using 3D Groundwater Simulation Results
2014-08-01
Hydraulics Engineering Technical Note (CHETN) is to document techniques for computing Factors of Safety (FoS) for seepage-related soil instability...topography, geology, sources or sinks , and boundary conditions along the length of the soil structure. If these conditions exist, a 3D model may be needed... hydraulic gradient, and iv is the exit gradient at the point of interest. The critical, stable, and unstable conditions are thus defined as FoS = 1, FoS
Factor Analysis of Drawings: Application to College Student Models of the Greenhouse Effect
Libarkin, Julie C.; Thomas, Stephen R.; Ording, Gabriel
2015-01-01
Exploratory factor analysis was used to identify models underlying drawings of the greenhouse effect made by over 200 entering university freshmen. Initial content analysis allowed deconstruction of drawings into salient features, with grouping of these features via factor analysis. A resulting 4-factor solution explains 62% of the data variance,…
Shape Modelling Using Maximum Autocorrelation Factors
DEFF Research Database (Denmark)
Larsen, Rasmus
2001-01-01
of the training set are in reality a time series, e.g.\\$\\backslash\\$ snapshots of a beating heart during the cardiac cycle or when the shapes are slices of a 3D structure, e.g. the spinal cord. Second, in almost all applications a natural order of the landmark points along the contour of the shape is introduced......This paper addresses the problems of generating a low dimensional representation of the shape variation present in a training set after alignment using Procrustes analysis and projection into shape tangent space. We will extend the use of principal components analysis in the original formulation...... of Active Shape Models by Timothy Cootes and Christopher Taylor by building new information into the model. This new information consists of two types of prior knowledge. First, in many situation we will be given an ordering of the shapes of the training set. This situation occurs when the shapes...
Using a knowledge elicitation method to specify the business model of a human factors organization
Schraagen, J.M.C.; Ven, J. van de; Hoffman, R.R.; Moon, B.M.
2009-01-01
Concept Mapping was used to structure knowledge elicitation interviews with a group of human factors specialists whose goal was to describe the business model of their Department. This novel use of cognitive task analysis to describe the business model of a human factors organization resulted in a n
Using a knowledge elicitation method to specify the business model of a human factors organization
Schraagen, J.M.C.; Ven, J. van de; Hoffman, R.R.; Moon, B.M.
2009-01-01
Concept Mapping was used to structure knowledge elicitation interviews with a group of human factors specialists whose goal was to describe the business model of their Department. This novel use of cognitive task analysis to describe the business model of a human factors organization resulted in a n
Using a knowledge elicitation method to specify the business model of a human factors organization.
Schraagen, Johannes Martinus Cornelis; van de Ven, Josine; Hoffman, Robert R.; Moon, Brian M.
2009-01-01
Concept Mapping was used to structure knowledge elicitation interviews with a group of human factors specialists whose goal was to describe the business model of their Department. This novel use of cognitive task analysis to describe the business model of a human factors organization resulted in a n
Instrumental Variable Bayesian Model Averaging via Conditional Bayes Factors
Karl, Anna; Lenkoski, Alex
2012-01-01
We develop a method to perform model averaging in two-stage linear regression systems subject to endogeneity. Our method extends an existing Gibbs sampler for instrumental variables to incorporate a component of model uncertainty. Direct evaluation of model probabilities is intractable in this setting. We show that by nesting model moves inside the Gibbs sampler, model comparison can be performed via conditional Bayes factors, leading to straightforward calculations. This new Gibbs sampler is...
Numerical Results of 3-D Modeling of Moon Accumulation
Khachay, Yurie; Anfilogov, Vsevolod; Antipin, Alexandr
2014-05-01
For the last time for the model of the Moon usually had been used the model of mega impact in which the forming of the Earth and its sputnik had been the consequence of the Earth's collision with the body of Mercurial mass. But all dynamical models of the Earth's accumulation and the estimations after the Pb-Pb system, lead to the conclusion that the duration of the planet accumulation was about 1 milliard years. But isotopic results after the W-Hf system testify about a very early (5-10) million years, dividing of the geochemical reservoirs of the core and mantle. In [1,2] it is shown, that the account of energy dissipating by the decay of short living radioactive elements and first of all Al26,it is sufficient for heating even small bodies with dimensions about (50-100) km up to the iron melting temperature and can be realized a principal new differentiation mechanism. The inner parts of the melted preplanets can join and they are mainly of iron content, but the cold silicate fragments return to the supply zone and additionally change the content of Moon forming to silicates. Only after the increasing of the gravitational radius of the Earth, the growing area of the future Earth's core can save also the silicate envelope fragments [3]. For understanding the further system Earth-Moon evolution it is significant to trace the origin and evolution of heterogeneities, which occur on its accumulation stage.In that paper we are modeling the changing of temperature,pressure,velocity of matter flowing in a block of 3d spherical body with a growing radius. The boundary problem is solved by the finite-difference method for the system of equations, which include equations which describe the process of accumulation, the Safronov equation, the equation of impulse balance, equation Navier-Stocks, equation for above litho static pressure and heat conductivity in velocity-pressure variables using the Businesque approach.The numerical algorithm of the problem solution in velocity
Studies of key success factors of product development success: A reinterpretation of results
DEFF Research Database (Denmark)
Plichta, Kirsten; Harmsen, Hanne
. The theoretical tradition of the resource-based perspective provides at least to some extent an account of this causality. An important point in the paper is that the key factors of success in the empi studies are not factors causally related to success, but at the most a number of valuable resources and thus......In this paper the general validity of the research area of key factors of success in product development is discussed. To be more specific we argue that validity hinges on the causal relation between success and success factrors a relation that unaccounted for in the empirical studies...... the necessary but not sufficient conditions for success. A second issue in the paper is the discussion of how the empirical results may be implemented in firms. The results of the empirical studies show managers where to concentrate their efforts in order to raise the rate of successful products...
Workforce scheduling: A new model incorporating human factors
Directory of Open Access Journals (Sweden)
Mohammed Othman
2012-12-01
Full Text Available Purpose: The majority of a company’s improvement comes when the right workers with the right skills, behaviors and capacities are deployed appropriately throughout a company. This paper considers a workforce scheduling model including human aspects such as skills, training, workers’ personalities, workers’ breaks and workers’ fatigue and recovery levels. This model helps to minimize the hiring, firing, training and overtime costs, minimize the number of fired workers with high performance, minimize the break time and minimize the average worker’s fatigue level.Design/methodology/approach: To achieve this objective, a multi objective mixed integer programming model is developed to determine the amount of hiring, firing, training and overtime for each worker type.Findings: The results indicate that the worker differences should be considered in workforce scheduling to generate realistic plans with minimum costs. This paper also investigates the effects of human fatigue and recovery on the performance of the production systems.Research limitations/implications: In this research, there are some assumptions that might affect the accuracy of the model such as the assumption of certainty of the demand in each period, and the linearity function of Fatigue accumulation and recovery curves. These assumptions can be relaxed in future work.Originality/value: In this research, a new model for integrating workers’ differences with workforce scheduling is proposed. To the authors' knowledge, it is the first time to study the effects of different important human factors such as human personality, skills and fatigue and recovery in the workforce scheduling process. This research shows that considering both technical and human factors together can reduce the costs in manufacturing systems and ensure the safety of the workers.
Realistic Models for Filling Factors in HII Regions
Spangler, Steven R.; Costa, Allison H.; Bergerud, Brandon M.; Beauchamp, Kara M.
2017-01-01
One of the parameters used to describe HII regions and other ionized parts of the interstellar medium is the filling factor, defined as the volume fraction of an HII region occupied by matter. The best observational evidence for the existence of a filling factor less than unity is a discrepancy between the electron density derived from density-sensitive line ratios and the root mean square density obtained from emission measure measurements. Following the early, influential study by Osterbrock and Flather (ApJ 129, 26, 1959), most investigations of HII regions envision these objects as a group of isolated cells of high gas density embedded in a vacuum. This picture is at serious odds with more direct measurements of other astrophysical plasmas like the solar wind, where the density follows a less extreme probability distribution function (pdf) such as an exponential or lognormal. We have carried out a set of simulations in which model HII regions are created with different density pdfs such as exponential and lognormal as well as the extreme case of two delta functions. We calculate the electron density as inferred from spectroscopic line ratios and emission measures for all lines of sight through the model nebulas. In the cases of exponential and lognormal pdfs, the spectroscopically derived densities are higher than those obtained by the emission measures by factors of 20 to 100 percent. These are considerably smaller than values often reported in the literature, which can be an order of magnitude or greater. We will discuss possible ways to reconcile realistic density pdfs such as measured in space and laboratory plasmas with the results from astronomical spectroscopic measurements. Finally, we point out that for the Orion Nebula, the density discrepancy is due to geometry, not filling factor (O'Dell, ARAA 39, 99, 2001).
Nucleon form factors in the canonically quantized Skyrme model
Energy Technology Data Exchange (ETDEWEB)
Acus, A.; Norvaisas, E. [Lithuanian Academy of Sciences, Vilnius (Lithuania). Inst. of Theoretical Physics and Astronomy; Riska, D.O. [Helsinki Univ. (Finland). Dept. of Physics; Helsinki Univ. (Finland). Helsinki Inst. of Physics
2001-08-01
The explicit expressions for the electric, magnetic, axial and induced pseudoscalar form factors of the nucleons are derived in the ab initio quantized Skyrme model. The canonical quantization procedure ensures the existence of stable soliton solutions with good quantum numbers. The form factors are derived for representations of arbitrary dimension of the SU(2) group. After fixing the two parameters of the model, f{sub {pi}} and e, by the empirical mass and electric mean square radius of the proton, the calculated electric and magnetic form factors are fairly close to the empirical ones, whereas the the axial and induced pseudoscalar form factors fall off too slowly with momentum transfer. (orig.)
Nucleon form factors in the canonically quantized Skyrme model
Acus, A; Riska, D O
2001-01-01
The explicit expressions for the electric, magnetic, axial and induced pseudoscalar form factors of the nucleons are derived in the {\\it ab initio} quantized Skyrme model. The canonical quantization procedure ensures the existence of stable soliton solutions with good quantum numbers. The form factors are derived for representations of arbitrary dimension of the SU(2) group. After fixing the two parameters of the model, $f_\\pi$ and $e$, by the empirical mass and electric mean square radius of the proton, the calculated electric and magnetic form factors are fairly close to the empirical ones, whereas the the axial and induced pseudoscalar form factors fall off too slowly with momentum transfer.
Higher-order factors of the big five model of personality: a reanalysis of Digman (1997).
Mutch, Christopher
2005-02-01
Based on the results from factor analyses conducted on 14 different data sets, Digman proposed a model of two higher-order factors, or metatraits, that subsumed the Big Five personality traits. In the current article, problems in Digman's analyses were explicated, and more appropriate analyses were then conducted using the same 14 correlation matrices from Digman's study. The resultant two-factor model produced improper solutions, poor model fit indices, or both, in almost all of the 14 data sets and thus raised serious doubts about the veracity of Digman's proposed model.
Comparison of blade-strike modeling results with empirical data
Energy Technology Data Exchange (ETDEWEB)
Ploskey, Gene R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carlson, Thomas J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2004-03-01
This study is the initial stage of further investigation into the dynamics of injury to fish during passage through a turbine runner. As part of the study, Pacific Northwest National Laboratory (PNNL) estimated the probability of blade strike, and associated injury, as a function of fish length and turbine operating geometry at two adjacent turbines in Powerhouse 1 of Bonneville Dam. Units 5 and 6 had identical intakes, stay vanes, wicket gates, and draft tubes, but Unit 6 had a new runner and curved discharge ring to minimize gaps between the runner hub and blades and between the blade tips and discharge ring. We used a mathematical model to predict blade strike associated with two Kaplan turbines and compared results with empirical data from biological tests conducted in 1999 and 2000. Blade-strike models take into consideration the geometry of the turbine blades and discharges as well as fish length, orientation, and distribution along the runner. The first phase of this study included a sensitivity analysis to consider the effects of difference in geometry and operations between families of turbines on the strike probability response surface. The analysis revealed that the orientation of fish relative to the leading edge of a runner blade and the location that fish pass along the blade between the hub and blade tip are critical uncertainties in blade-strike models. Over a range of discharges, the average prediction of injury from blade strike was two to five times higher than average empirical estimates of visible injury from shear and mechanical devices. Empirical estimates of mortality may be better metrics for comparison to predicted injury rates than other injury measures for fish passing at mid-blade and blade-tip locations.
Evaluation of the Thermodynamic Models for the Thermal Diffusion Factor
DEFF Research Database (Denmark)
Gonzalez-Bagnoli, Mariana G.; Shapiro, Alexander; Stenby, Erling Halfdan
2003-01-01
Over the years, several thermodynamic models for the thermal diffusion factors for binary mixtures have been proposed. The goal of this paper is to test some of these models in combination with different equations of state. We tested the following models: those proposed by Rutherford and Drickame...
Position-sensitive transition edge sensor modeling and results
Energy Technology Data Exchange (ETDEWEB)
Hammock, Christina E-mail: chammock@milkyway.gsfc.nasa.gov; Figueroa-Feliciano, Enectali; Apodaca, Emmanuel; Bandler, Simon; Boyce, Kevin; Chervenak, Jay; Finkbeiner, Fred; Kelley, Richard; Lindeman, Mark; Porter, Scott; Saab, Tarek; Stahle, Caroline
2004-03-11
We report the latest design and experimental results for a Position-Sensitive Transition-Edge Sensor (PoST). The PoST is motivated by the desire to achieve a larger field-of-view without increasing the number of readout channels. A PoST consists of a one-dimensional array of X-ray absorbers connected on each end to a Transition Edge Sensor (TES). Position differentiation is achieved through a comparison of pulses between the two TESs and X-ray energy is inferred from a sum of the two signals. Optimizing such a device involves studying the available parameter space which includes device properties such as heat capacity and thermal conductivity as well as TES read-out circuitry parameters. We present results for different regimes of operation and the effects on energy resolution, throughput, and position differentiation. Results and implications from a non-linear model developed to study the saturation effects unique to PoSTs are also presented.
Long-term results, prognostic factors and cataract surgery after diabetic vitrectomy
DEFF Research Database (Denmark)
Ostri, Christoffer; Lux, Anja; Lund-Andersen, Henrik
2014-01-01
PURPOSE: To report long-term results, prognostic factors and cataract surgery after diabetic vitrectomy. METHODS: Retrospective review of patient files from a large diabetes centre between 1996 and 2010. Surgical history was obtained from the Danish National Patient Register. Follow-up intervals ...
Risk factors for different phenotypes of hypospadias: results from a Dutch case-control study
Rooij, I.A.L.M. van; Zanden, L.F.M. van der; Brouwers, M.M.; Knoers, N.V.A.M.; Feitz, W.F.J.; Roeleveld, N.
2013-01-01
WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: The various phenotypes of hypospadias may result from disturbances of dissimilar embryonic processes in different time windows, suggesting aetiological heterogeneity; however, only a few studies have investigated the risk factors for the dif
van Riemsdijk, I C; Baan, C C; Loonen, E H; Knoop, C J; Navarro Betonico, G; Niesters, H G; Zietse, R; Weimar, W
2001-01-01
BACKGROUND: The immunosuppressive state of hemodialysis (HD) patients is accompanied by activation of antigen-presenting cell-derived cytokines, for example, tumor necrosis factor-alpha (TNF-alpha), which are required for T-cell activation. To test whether an activated TNF-alpha system results in im
MODELING RESULTS FROM CESIUM ION EXCHANGE PROCESSING WITH SPHERICAL RESINS
Energy Technology Data Exchange (ETDEWEB)
Nash, C.; Hang, T.; Aleman, S.
2011-01-03
Ion exchange modeling was conducted at the Savannah River National Laboratory to compare the performance of two organic resins in support of Small Column Ion Exchange (SCIX). In-tank ion exchange (IX) columns are being considered for cesium removal at Hanford and the Savannah River Site (SRS). The spherical forms of resorcinol formaldehyde ion exchange resin (sRF) as well as a hypothetical spherical SuperLig{reg_sign} 644 (SL644) are evaluated for decontamination of dissolved saltcake wastes (supernates). Both SuperLig{reg_sign} and resorcinol formaldehyde resin beds can exhibit hydraulic problems in their granular (nonspherical) forms. SRS waste is generally lower in potassium and organic components than Hanford waste. Using VERSE-LC Version 7.8 along with the cesium Freundlich/Langmuir isotherms to simulate the waste decontamination in ion exchange columns, spherical SL644 was found to reduce column cycling by 50% for high-potassium supernates, but sRF performed equally well for the lowest-potassium feeds. Reduced cycling results in reduction of nitric acid (resin elution) and sodium addition (resin regeneration), therefore, significantly reducing life-cycle operational costs. These findings motivate the development of a spherical form of SL644. This work demonstrates the versatility of the ion exchange modeling to study the effects of resin characteristics on processing cycles, rates, and cold chemical consumption. The value of a resin with increased selectivity for cesium over potassium can be assessed for further development.
Dipole model test with one superconducting coil; results analysed
Durante, M; Ferracin, P; Fessia, P; Gauthier, R; Giloux, C; Guinchard, M; Kircher, F; Manil, P; Milanese, A; Millot, J-F; Muñoz Garcia, J-E; Oberli, L; Perez, J-C; Pietrowicz, S; Rifflet, J-M; de Rijk, G; Rondeaux, F; Todesco, E; Viret, P; Ziemianski, D
2013-01-01
This report is the deliverable report 7.3.1 “Dipole model test with one superconducting coil; results analysed “. The report has four parts: “Design report for the dipole magnet”, “Dipole magnet structure tested in LN2”, “Nb3Sn strand procured for one dipole magnet” and “One test double pancake copper coil made”. The 4 report parts show that, although the magnet construction will be only completed by end 2014, all elements are present for a successful completion. Due to the importance of the project for the future of the participants and given the significant investments done by the participants, there is a full commitment to finish the project.
Dipole model test with one superconducting coil: results analysed
Bajas, H; Benda, V; Berriaud, C; Bajko, M; Bottura, L; Caspi, S; Charrondiere, M; Clément, S; Datskov, V; Devaux, M; Durante, M; Fazilleau, P; Ferracin, P; Fessia, P; Gauthier, R; Giloux, C; Guinchard, M; Kircher, F; Manil, P; Milanese, A; Millot, J-F; Muñoz Garcia, J-E; Oberli, L; Perez, J-C; Pietrowicz, S; Rifflet, J-M; de Rijk, G; Rondeaux, F; Todesco, E; Viret, P; Ziemianski, D
2013-01-01
This report is the deliverable report 7.3.1 “Dipole model test with one superconducting coil; results analysed “. The report has four parts: “Design report for the dipole magnet”, “Dipole magnet structure tested in LN2”, “Nb3Sn strand procured for one dipole magnet” and “One test double pancake copper coil made”. The 4 report parts show that, although the magnet construction will be only completed by end 2014, all elements are present for a successful completion. Due to the importance of the project for the future of the participants and given the significant investments done by the participants, there is a full commitment to finish the project.
Insufficiently studied factors related to burnout in nursing: Results from an e-Delphi study
2017-01-01
Objective This study aimed to identify potentially important factors in explaining burnout in nursing that have been insufficiently studied or ignored. Methods A three-round Delphi study via e-mail correspondence was conducted, with a group of 40 European experts. The e-Delphi questionnaire consisted of 52 factors identified from a literature review. Experts rated and scored the importance of factors in the occurrence of burnout and the degree of attention given by researchers to each of the variables listed, on a six-point Likert scale. We used the agreement percentage (>80%) to measure the level of consensus between experts. Furthermore, to confirm the level of consensus, we also calculated mean scores and modes. Regardless of the degree of consensus reached by the experts, we have calculated the mean of the stability of the answers for each expert (individual's qualitative stability) and the mean of the stability percentages of the experts (qualitative group stability). Results The response rate in the three rounds was 93.02% (n = 40). Eight new factors were suggested in the first round. After modified, the e-Delphi questionnaire in the second and third rounds had 60 factors. All the factors reached the third round with a consensus level above 80% in terms of the attention that researchers gave them in their studies. Moreover, the data show a total mean qualitative group stability of 96.21%. In the third round 9 factors were classified by experts as ‘studied very little’, 17 as ‘studied little’ and 34 as 'well studied' Conclusion Findings show that not all the factors that may influence nursing burnout have received the same attention from researchers. The panel of experts has identified factors that, although important in explaining burnout, have been poorly studied or even forgotten. Our results suggest that further study into factors such as a lack of recognition of part of the tasks that nurses perform, feminine stereotype or excessive bureaucracy is
Analytic results for planar three-loop integrals for massive form factors
Henn, Johannes M.; Smirnov, Alexander V.; Smirnov, Vladimir A.
2016-12-01
We use the method of differential equations to analytically evaluate all planar three-loop Feynman integrals relevant for form factor calculations involving massive particles. Our results for ninety master integrals at general q 2 are expressed in terms of multiple polylogarithms, and results for fiftyone master integrals at the threshold q 2 = 4 m 2 are expressed in terms of multiple polylogarithms of argument one, with indices equal to zero or to a sixth root of unity.
Analytic results for planar three-loop integrals for massive form factors
Henn, Johannes M; Smirnov, Vladimir A
2016-01-01
We use the method of differential equations to analytically evaluate all planar three-loop Feynman integrals relevant for form factor calculations involving massive particles. Our results for ninety master integrals at general $q^2$ are expressed in terms of multiple polylogarithms, and results for fiftyone master integrals at the threshold $q^2=4m^2$ are expressed in terms of multiple polylogarithms of argument one, with indices equal to zero or to a sixth root of unity.
Further Results on Dynamic Additive Hazard Rate Model
Directory of Open Access Journals (Sweden)
Zhengcheng Zhang
2014-01-01
Full Text Available In the past, the proportional and additive hazard rate models have been investigated in the works. Nanda and Das (2011 introduced and studied the dynamic proportional (reversed hazard rate model. In this paper we study the dynamic additive hazard rate model, and investigate its aging properties for different aging classes. The closure of the model under some stochastic orders has also been investigated. Some examples are also given to illustrate different aging properties and stochastic comparisons of the model.
The determinant factors of open business model
Directory of Open Access Journals (Sweden)
Juan Mejía-Trejo
2017-01-01
Full Text Available Intro ducción : Desde principios del siglo XXI, varios autores afirman que los modelos de negocio abiertos (OBM permiten a una organización ser más eficaz en la creación y la ca p tura de valor siendo un requisito previo para el éxito de las asociaciones de co - des arrollo. Como resultado de las tendencias de: crecientes costos de desarrollo y ciclos de vida de los produ c tos/servicios más cortos, las empresas encuentran cada vez más difícil justificar las inversi o nes en innovación. El OBM resuelve ambas tendencias, s ubrayando los términos: " ecosistema de la industria " y/o " modelo de negocio colaborativo ". No sólo cambia el pr o ceso de innovación, sino que también modifica a las propias organizaciones mediante la r e configuración de sus cadenas de valor y redes. Para las empresas, crea una lógica heurística basada en el actual modelo de negocio y tecnología para extenderlas, con estrategia, al desa r rollo de la innov a ción para crear valor y aumentar los ingresos y beneficios. Enfatiza tanto las relaciones exte r nas así como la gobernabilidad, como valiosos recursos con varios roles que promueven la competitividad corporativa. Por lo tanto, para un sector especializado de alta tecnología como lo es el de las tecnologías de la información de la zona metropolitana de Guadalajar a (IT S MZG, exponemos el siguiente problema de investigación: ¿Cuáles son los factores determinantes de la OBM como modelo empírico que se aplc a do en el ITSMZG? Método: Como se ve, esta investigación tiene como objetivo plantear, los factores determ i nantes de la OBM como un modelo empírico que sea aplicado en el ITSMZG.Se trata de un estudio documental para seleccionar las principales v a riables entre los especialistas de las ITSMZG que practican el proceso OBM mediante el proceso de j e rarquía analítica (AHP y el Panel de Delphi a fin de contrastar los términos académicos con la experiencia de los e s pecialistas. Es un
[Genetic and environmental factors of asthma and allergy: Results of the EGEA study].
Bouzigon, E; Nadif, R; Le Moual, N; Dizier, M-H; Aschard, H; Boudier, A; Bousquet, J; Chanoine, S; Donnay, C; Dumas, O; Gormand, F; Jacquemin, B; Just, J; Margaritte-Jeannin, P; Matran, R; Pison, C; Rage, E; Rava, M; Sarnowski, C; Smit, L A M; Temam, S; Varraso, R; Vignoud, L; Lathrop, M; Pin, I; Demenais, F; Kauffmann, F; Siroux, V
2015-10-01
The EGEA study (epidemiological study on the genetics and environment of asthma, bronchial hyperresponsiveness and atopy), which combines a case-control and a family-based study of asthma case (n=2120 subjects) with three surveys over 20 years, aims to identify environmental and genetic factors associated with asthma and asthma-related phenotypes. We summarize the results of the phenotypic characterization and the investigation of environmental and genetic factors of asthma and asthma-related phenotypes obtained since 2007 in the EGEA study (42 articles). Both epidemiological and genetic results confirm the heterogeneity of asthma. These results strengthen the role of the age of disease onset, the allergic status and the level of disease activity in the identification of the different phenotypes of asthma. The deleterious role of active smoking, exposure to air pollution, occupational asthmogenic agents and cleaning products on the prevalence and/or activity of asthma has been confirmed. Accounting for gene-environment interactions allowed the identification of new genetic factors underlying asthma and asthma-related traits and better understanding of their mode of action. The EGEA study is contributing to the advances in respiratory research at the international level. The new phenotypic, environmental and biological data available in EGEA study will help characterizing the long-term evolution of asthma and the factors associated to this evolution. Copyright © 2015 SPLF. Published by Elsevier Masson SAS. All rights reserved.
Multivariate poisson-lognormal model for modeling related factors in crash frequency by severity
Directory of Open Access Journals (Sweden)
Mehdi Tazhibi
2013-01-01
Full Text Available Aims: Traditionally, roadway safety analyses have used univariate distributions to model crash data for each level of severity separately. This paper uses the multivariate Poisson lognormal (MVPLN models to estimate the expected crash frequency by two levels of severity and then compares those estimates with the univariate Poisson-lognormal (UVPLN and the univariate Poisson (UVP models. Materials and Methods: The parameters estimation is done by Bayesian method for crash data at two levels of severity at the intersection of Isfahan city for 6 months. Results: The results showed that there was over-dispersion issue in data. The UVP model is not able to overcome this problem while the MVPLN model can account for over-dispersion. Also, the estimates of the extra Poisson variation parameters in the MVPLN model were smaller than the UVPLN model that causes improvement in the precision of the MNPLN model. Hence, the MVPLN model is better fitted to the data set. Also, results showed effect of the total Average annual daily traffic (AADT on the property damage only crash was significant in the all of models but effect of the total left turn AADT on the injuries and fatalities crash was significant just in the UVP model. Hence, holding all other factors fixed more property damage only crashes were expected on more the total AADT. For example, under MVPLN model an increase of 1000 vehicles in (average the total AADT was predicted to result in 31% more property damage only crash. Conclusion: Hence, reduction of total AADT was predicted to be highly cost-effective, in terms of the crash cost reductions over the long run.
Selection between Linear Factor Models and Latent Profile Models Using Conditional Covariances
Halpin, Peter F.; Maraun, Michael D.
2010-01-01
A method for selecting between K-dimensional linear factor models and (K + 1)-class latent profile models is proposed. In particular, it is shown that the conditional covariances of observed variables are constant under factor models but nonlinear functions of the conditioning variable under latent profile models. The performance of a convenient…
Selection between Linear Factor Models and Latent Profile Models Using Conditional Covariances
Halpin, Peter F.; Maraun, Michael D.
2010-01-01
A method for selecting between K-dimensional linear factor models and (K + 1)-class latent profile models is proposed. In particular, it is shown that the conditional covariances of observed variables are constant under factor models but nonlinear functions of the conditioning variable under latent profile models. The performance of a convenient…
Form factors of the monodromy matrix entries in gl(2|1)-invariant integrable models
Hutsalyuk, A; Pakuliak, S Z; Ragoucy, E; Slavnov, N A
2016-01-01
We study integrable models solvable by the nested algebraic Bethe ansatz and described by $\\mathfrak{gl}(2|1)$ or $\\mathfrak{gl}(1|2)$ superalgebras. We obtain explicit determinant representations for form factors of the monodromy matrix entries. We show that all form factors are related to each other at special limits of the Bethe parameters. Our results allow one to obtain determinant formulas for form factors of local operators in the supersymmetric t-J model.
Form factors of the monodromy matrix entries in gl (2 | 1)-invariant integrable models
Hutsalyuk, A.; Liashyk, A.; Pakuliak, S. Z.; Ragoucy, E.; Slavnov, N. A.
2016-10-01
We study integrable models solvable by the nested algebraic Bethe ansatz and described by gl (2 | 1) or gl (1 | 2) superalgebras. We obtain explicit determinant representations for form factors of the monodromy matrix entries. We show that all form factors are related to each other at special limits of the Bethe parameters. Our results allow one to obtain determinant formulas for form factors of local operators in the supersymmetric t- J model.
Model of key success factors for Business Intelligence implementation
Directory of Open Access Journals (Sweden)
Peter Mesaros
2016-07-01
Full Text Available New progressive technologies recorded growth in every area. Information-communication technologies facilitate the exchange of information and it facilitates management of everyday activities in enterprises. Specific modules (such as Business Intelligence facilitate decision-making. Several studies have demonstrated the positive impact of Business Intelligence to decision-making. The first step is to put in place the enterprise. The implementation process is influenced by many factors. This article discusses the issue of key success factors affecting to successful implementation of Business Intelligence. The article describes the key success factors for successful implementation and use of Business Intelligence based on multiple studies. The main objective of this study is to verify the effects and dependence of selected factors and proposes a model of key success factors for successful implementation of Business Intelligence. Key success factors and the proposed model are studied in Slovak enterprises.
Energy Technology Data Exchange (ETDEWEB)
Cliff, K.D.; Miles, J.C.H.; Naismith, S.P. [National Radiological Protection Board, Chilton (United Kingdom)
1994-12-31
Data from the UK national survey of radon in 2300 homes has been re-analysed to determine the uncertainty in seasonal correction factors applied to measurements of less than 1 year. The required correction factor for each six-month result was calculated from the known annual average for the appropriate home. The seasonal correction factors derived for each month were found to be approximately log-normally distributed, with an average geometric standard deviation of 1.36. Following this initial survey, radon measurements have been made in more than 80,000 homes in southwest England to determine whether they are above the UK radon Action Level of 2000 Bq.m{sup -3}. The measurements were carried out over three months in each case using etched track detectors in two locations in each home, and the results were corrected for the average seasonal variation found in the original UK study of radon in homes. Because of the uncertainty in the seasonal correction factors, households with between 130 and 300 Bq.m{sup -3} were advised to have a second three-month measurement in a different season before deciding whether or not to take remedial action. More than 7000 homes were remonitored for this purpose. The results are analysed to show the number of false positive and false negative results that would have been reported if advice had been based solely on the initial measurement. It is shown that the present scheme results in extremely small numbers of false positive and false negative results. (author).
The development of a theoretical model to investigate factors ...
African Journals Online (AJOL)
The development of a theoretical model to investigate factors associated with ... major household appliance market: An integrative conceptual approach. ... disadvantaged consumers gain spending power and access to electricity supply.
Mouse Model of Neurological Complications Resulting from Encephalitic Alphavirus Infection
Ronca, Shannon E.; Smith, Jeanon; Koma, Takaaki; Miller, Magda M.; Yun, Nadezhda; Dineley, Kelly T.; Paessler, Slobodan
2017-01-01
Long-term neurological complications, termed sequelae, can result from viral encephalitis, which are not well understood. In human survivors, alphavirus encephalitis can cause severe neurobehavioral changes, in the most extreme cases, a schizophrenic-like syndrome. In the present study, we aimed to adapt an animal model of alphavirus infection survival to study the development of these long-term neurological complications. Upon low-dose infection of wild-type C57B/6 mice, asymptomatic and symptomatic groups were established and compared to mock-infected mice to measure general health and baseline neurological function, including the acoustic startle response and prepulse inhibition paradigm. Prepulse inhibition is a robust operational measure of sensorimotor gating, a fundamental form of information processing. Deficits in prepulse inhibition manifest as the inability to filter out extraneous sensory stimuli. Sensory gating is disrupted in schizophrenia and other mental disorders, as well as neurodegenerative diseases. Symptomatic mice developed deficits in prepulse inhibition that lasted through 6 months post infection; these deficits were absent in asymptomatic or mock-infected groups. Accompanying prepulse inhibition deficits, symptomatic animals exhibited thalamus damage as visualized with H&E staining, as well as increased GFAP expression in the posterior complex of the thalamus and dentate gyrus of the hippocampus. These histological changes and increased GFAP expression were absent in the asymptomatic and mock-infected animals, indicating that glial scarring could have contributed to the prepulse inhibition phenotype observed in the symptomatic animals. This model provides a tool to test mechanisms of and treatments for the neurological sequelae of viral encephalitis and begins to delineate potential explanations for the development of such sequelae post infection.
A Duality Result for the Generalized Erlang Risk Model
Directory of Open Access Journals (Sweden)
Lanpeng Ji
2014-11-01
Full Text Available In this article, we consider the generalized Erlang risk model and its dual model. By using a conditional measure-preserving correspondence between the two models, we derive an identity for two interesting conditional probabilities. Applications to the discounted joint density of the surplus prior to ruin and the deficit at ruin are also discussed.
Rethinking "Harmonious Parenting" Using a Three-Factor Discipline Model
Greenspan, Stephen
2006-01-01
Diana Baumrind's typology of parenting is based on a two-factor model of "control" and "warmth". Her recommended discipline style, labeled "authoritative parenting", was constructed by taking high scores on these two factors. A problem with authoritative parenting is that it does not allow for flexible and differentiated responses to discipline…
Form factors in an algebraic model of the nucleon
Bijker, R
1995-01-01
We study the electromagnetic form factors of the nucleon in a collective model of baryons. In an algebraic approach to hadron structure, we derive closed expressions for both elastic and transition form factors, and consequently for the helicity amplitudes that can be measured in electro- and photoproduction.
Relativistic quark model for the Omega- electromagnetic form factors
Energy Technology Data Exchange (ETDEWEB)
G. Ramalho, K. Tsushima, Franz Gross
2009-08-01
We compute the Omega- electromagnetic form factors and the decuplet baryon magnetic moments using a quark model application of the Covariant Spectator Theory. Our predictions for the Omega- electromagnetic form factors can be tested in the future by lattice QCD simulations at the physical strange quark mass.
A relativistic quark model for the Omega- electromagnetic form factors
Ramalho, G; Gross, Franz
2009-01-01
We compute the Omega- electromagnetic form factors and the decuplet baryon magnetic moments using a quark model application of the Covariant Spectator Theory. Our predictions for the Omega- electromagnetic form factors can be tested in the future by lattice QCD simulations at the physical strange quark mass.
Rethinking "Harmonious Parenting" Using a Three-Factor Discipline Model
Greenspan, Stephen
2006-01-01
Diana Baumrind's typology of parenting is based on a two-factor model of "control" and "warmth". Her recommended discipline style, labeled "authoritative parenting", was constructed by taking high scores on these two factors. A problem with authoritative parenting is that it does not allow for flexible and differentiated responses to discipline…
Energy Technology Data Exchange (ETDEWEB)
Huber, Garth; Blok, Henk; Horn, Tanja; Beise, Elizabeth; Gaskell, David; Mack, David; Tadevosyan, Vardan; Volmer, Jochen; Abbott, David; Aniol, Konrad; Anklin, Heinz; Armstrong, Christopher; Arrington, John; Assamagan, Ketevi; Avery, Steven; Baker, O.; Barrett, Robert; Bochna, Christopher; Boeglin, Werner; Brash, Edward; Breuer, Herbert; Chang, C.; Chang, C.C.; Chant, Nicholas; Christy, Michael; Dunne, James; Eden, Thomas; Ent, Rolf; Fenker, Benjamin; Gibson, Edward; Gilman, Ronald; Gustafsson, Kenneth; Hinton, Wendy; Holt, Roy; Jackson, Harold; uk Jin, Seong; Jones, Mark; Keppel, Cynthia; Kim, pyunghun; Kim, Wooyoung; King, Paul; Klein, Andreas; Koltenuk, Douglas; Kovaltchouk, Vitali; Liang, Meihua; Liu, Jinghua; Lolos, George; Lung, Allison; Margaziotis, Demetrius; Markowitz, Pete; Matsumura, Akihiko; McKee, David; Meekins, David; Mitchell, Joseph; Miyoshi, Toshinobu; Mkrtchyan, Hamlet; Mueller, Robert; Niculescu, Gabriel; Niculescu, Maria-Ioana; Okayasu, Yuichi; Pentchev, Lubomir; Perdrisat, Charles; Pitz, David; Potterveld, David; Punjabi, Vina; Qin, Liming; Reimer, Paul; Reinhold, Joerg; Roche, Julie; Roos, Philip; Sarty, Adam; Shin, Ilkyoung; Smith, Gregory; Stepanyan, Stepan; Tang, Liguang; Tvaskis, Vladas; van der Meer, Rob; Vansyoc, Kelley; Van Westrum, Derek; Vidakovic, Sandra; Vulcan, William; Warren, Glen; Wood, Stephen; Xu, Chen; Yan, Chen; Zhao, Wenxia; Zheng, Xiaochao; Zihlmann, Benedikt
2008-10-01
DOI: http://dx.doi.org/10.1103/PhysRevC.78.045203
The charged pion form factor, Fpi(Q2), is an important quantity that can be used to advance our knowledge of hadronic structure. However, the extraction of Fpi from data requires a model of the 1H(e,e'pi+)n reaction and thus is inherently model dependent. Therefore, a detailed description of the extraction of the charged pion form factor from electroproduction data obtained recently at Jefferson Lab is presented, with particular focus given to the dominant uncertainties in this procedure. Results for Fpi are presented for Q2=0.60-2.45 GeV2. Above Q2=1.5 GeV2, the Fpi values are systematically below the monopole parametrization that describes the low Q2 data used to determine the pion charge radius. The pion form factor can be calculated in a wide variety of theoretical approaches, and the experimental results are compared to a number of calculations. This comparison is helpful in understanding the role of soft versus hard c
Huber, G M; Horn, T; Beise, E J; Gaskell, D; Mack, D J; Tadevosyan, V; Volmer, J; Abbott, D; Aniol, K; Anklin, H; Armstrong, C; Arrington, J; Assamagan, K; Avery, S; Baker, O K; Barrett, B; Bochna, C; Boeglin, W; Brash, E J; Breuer, H; Chang, C C; Chant, N; Christy, M E; Dunne, J; Eden, T; Ent, R; Gibson, E; Gilman, R; Gustafsson, K; Hinton, W; Holt, R J; Jackson, H; Jin, S; Jones, M K; Keppel, C E; Kim, P H; Kim, W; King, P M; Klein, A; Koltenuk, D; Kovaltchouk, V; Kiang, M; Liu, J; Lolos, G J; Lung, A; Margaziotis, D J; Markowitz, P; Matsumura, A; McKee, D; Meekins, D; Mitchell, J; Miyoshi, T; Mkrtchyan, H; Müller, B; Niculescu, G; Niculescu, I; Okayasu, Y; Pentchev, L; Perdrisat, C; Pitz, D; Potterveld, D; Punjabi, V; Qin, L M; Reimer, P; Reinhold, J; Roche, J; Roos, P G; Sarty, A; Shin, I K; Smith, G R; Stepanyan, S; Tang, L G; Tvaskis, V; Van der Meer, R L J; Vansyoc, K; Van Westrum, D; Vidakovic, S; Vulcan, W; Warren, G; Wood, S A; Xu, C; Yan, C; Zhao, W -X; Zheng, X; Zihlmann, B
2008-01-01
The charged pion form factor, Fpi(Q^2), is an important quantity which can be used to advance our knowledge of hadronic structure. However, the extraction of Fpi from data requires a model of the 1H(e,e'pi+)n reaction, and thus is inherently model dependent. Therefore, a detailed description of the extraction of the charged pion form factor from electroproduction data obtained recently at Jefferson Lab is presented, with particular focus given to the dominant uncertainties in this procedure. Results for Fpi are presented for Q^2=0.60-2.45 GeV^2. Above Q^2=1.5 GeV^2, the Fpi values are systematically below the monopole parameterization that describes the low Q^2 data used to determine the pion charge radius. The pion form factor can be calculated in a wide variety of theoretical approaches, and the experimental results are compared to a number of calculations. This comparison is helpful in understanding the role of soft versus hard contributions to hadronic structure in the intermediate Q^2 regime.
Is There Really a Global Business Cycle? : A Dynamic Factor Model with Stochastic Factor Selection
T. Berger (Tino); L.C.G. Pozzi (Lorenzo)
2016-01-01
textabstractWe investigate the presence of international business cycles in macroeconomic aggregates (output, consumption, investment) using a panel of 60 countries over the period 1961-2014. The paper presents a Bayesian stochastic factor selection approach for dynamic factor models with
Energy Technology Data Exchange (ETDEWEB)
Fagedet, Dorothee, E-mail: DFagedet@chu-grenoble.fr [CHU de Grenoble, Clinique universitaire de medecine interne, Pole Pluridisciplinaire de Medecine (France); Thony, Frederic, E-mail: FThony@chu-grenoble.fr [CHU de Grenoble, Clinique universitaire de radiologie et imagerie medicale, Pole d' Imagerie (France); Timsit, Jean-Francois, E-mail: JFTimsit@chu-grenoble.fr [CHU de Grenoble, Clinique universitaire de reanimation, Pole Medecine Aiguee Communautaire (France); Rodiere, Mathieu, E-mail: MRodiere@chu-grenoble.fr [CHU de Grenoble, Clinique universitaire de radiologie et imagerie medicale, Pole d' Imagerie (France); Monnin-Bares, Valerie, E-mail: v-monnin@chu-montpellier.fr [CHRU Arnaud de Villeneuve, Imagerie Medicale Thoracique Cardiovasculaire (France); Ferretti, Gilbert R., E-mail: GFerretti@chu-grenoble.fr [CHU de Grenoble, Clinique universitaire de radiologie et imagerie medicale, Pole d' Imagerie (France); Vesin, Aurelien; Moro-Sibilot, Denis, E-mail: DMoro.pneumo@chu-grenoble.fr [University Grenoble 1 e Albert Bonniot Institute, Inserm U823 (France)
2013-02-15
To demonstrate the effectiveness of endovascular treatment (EVT) with self-expandable bare stents for malignant superior vena cava syndrome (SVCS) and to analyze predictive factors of EVT efficacy. Retrospective review of the 164 patients with malignant SVCS treated with EVT in our hospital from August 1992 to December 2007 and followed until February 2009. Endovascular treatment includes angioplasty before and after stent placement. We used self-expandable bare stents. We studied results of this treatment and looked for predictive factors of clinical efficacy, recurrence, and complications by statistical analysis. Endovascular treatment was clinically successful in 95% of cases, with an acceptable rate of early mortality (2.4%). Thrombosis of the superior vena cava was the only independent factor for EVT failure. The use of stents over 16 mm in diameter was a predictive factor for complications (P = 0.008). Twenty-one complications (12.8%) occurred during the follow-up period. Relapse occurred in 36 patients (21.9%), with effective restenting in 75% of cases. Recurrence of SVCS was significantly increased in cases of occlusion (P = 0.01), initial associated thrombosis (P = 0.006), or use of steel stents (P = 0.004). Long-term anticoagulant therapy did not influence the risk of recurrence or complications. In malignancy, EVT with self-expandable bare stents is an effective SVCS therapy. These results prompt us to propose treatment with stents earlier in the clinical course of patients with SVCS and to avoid dilatation greater than 16 mm.
Energy Technology Data Exchange (ETDEWEB)
GARVIN, L.J.
1999-09-20
The purpose for this supplemental report is to follow-up and update the information in SNF-3907, Human Factors Engineering (HFE) Analysis: Results and Findings. This supplemental report responds to applicable U.S. Department of Energy Safety Analysis Report review team comments and questions. This Human Factors Engineering and Ergonomics (HFE/Erg) analysis was conducted from April 1999 to July 1999; SNF-3907 was based on analyses accomplished in October 1998. The HFE/Erg findings presented in this report and SNF-3907, along with the results of HNF-3553, Spent Nuclear Fuel Project, Final Safety Analysis Report, Annex A, ''Canister Storage Building Final Safety Analysis Report,'' Chapter A3.0, ''Hazards and Accidents Analyses,'' provide the technical basis for preparing or updating HNF-3553. Annex A, Chaptex A13.0, ''Human Factors Engineering.'' The findings presented in this report allow the HNF-3553 Chapter 13.0, ''Human Factors,'' to respond fully to the HFE requirements established in DOE Order 5480.23, Nuclear Safety Analysis Reports.
Institute of Scientific and Technical Information of China (English)
Yun-chun Li; Fan Yang; Xiao-yun Ji; Zhong-jun Fang; Jun Liu; Yue Wang
2014-01-01
Objective To investigate if immunological factors associated with rheumatoid arthritis (RA) affect the result of human immunodeficiency virus (HIV) screening by electrochemiluminescence immunoassay (ECLIA) and enzyme-linked immunosorbent assay (ELISA). Methods 100 RA cases were enrolled from January 2012 to February 2013 into this study. HIV screening was conducted with ECLIA detecting both HIV-1 p24 antigen, HIV-1 and HIV-2 antibodies, with ELISA and colloidal gold method detecting HIV-1 and HIV-2 antibodies. The samples producing positive results were submitted to the Center for Disease Control for confirmation using Western blotting method. The antibody titers of rheumatoid factors (RF) including RF-IgG, RF-IgM, RF-IgA, and CCP-IgG were analyzed by ELISA. Results The HIV positive-rate determined by ECLIA was significantly higher than that by ELISA and colloidal gold method (P Conclusion Immunological factors, including RF and anti-CCP antibody, may influence the screening of HIV by ECLIA, producing false-positive result.
On the evaluation of box model results: the case of BOXURB model.
Paschalidou, A K; Kassomenos, P A
2009-08-01
In the present paper, the BOXURB model results, as they occurred in the Greater Area of Athens after model application on an hourly basis for the 10-year period 1995-2004, are evaluated both in time and space in the light of observed pollutant concentrations time series from 17 monitoring stations. The evaluation is performed at a total, monthly, daily and hourly scale. The analysis also includes evaluation of the model performance with regard to the meteorological parameters. Finally, the model is evaluated as an air quality forecasting and urban planning tool. Given the simplicity of the model and the complexity of the area topography, the model results are found to be in good agreement with the measured pollutant concentrations, especially in the heavy traffic stations. Therefore, the model can be used for regulatory purposes by authorities for time-efficient, simple and reliable estimation of air pollution levels within city boundaries.
Directory of Open Access Journals (Sweden)
Joris Mulder
2012-01-01
Full Text Available This paper discusses a Fortran 90 program referred to asBIEMS (Bayesian inequality and equality constrained model selection that can be used for calculating Bayes factors of multivariate normal linear models with equality and/or inequality constraints betweenthe model parameters versus a model containing no constraints, which is referred to as the unconstrained model. The prior that is used under the unconstrained model is the conjugate expected-constrained posterior prior and the prior under the constrained model is proportional to the unconstrained prior truncated in the constrained space. This results in Bayes factors that appropriately balance between model t and complexity for a broad class of constrained models. When the set of equality and/or inequality constraints in the model represents a hypothesis that applied researchers have in, for instance, (MAN(COVA, (multivariate regression, or repeated measurements, the obtained Bayes factor can be used to determine how much evidence is provided by the data in favor of the hypothesis in comparison to the unconstrained model. If several hypotheses are underinvestigation, the Bayes factors between the constrained models can be calculated using the obtained Bayes factors from BIEMS. Furthermore, posterior model probabilities of constrained models are provided which allows the user to compare the models directlywith each other.
Directory of Open Access Journals (Sweden)
Hankins Matthew
2008-04-01
Full Text Available Abstract Background The 12-item General Health Questionnaire (GHQ-12 is used routinely as a unidimensional measure of psychological morbidity. Many factor-analytic studies have reported that the GHQ-12 has two or three dimensions, threatening its validity. It is possible that these 'dimensions' are the result of the wording of the GHQ-12, namely its division into positively phrased (PP and negatively phrased (NP statements about mood states. Such 'method effects' introduce response bias which should be taken into account when deriving and interpreting factors. Methods GHQ-12 data were obtained from the 2004 cohort of the Health Survey for England (N = 3705. Following exploratory factor analysis (EFA, the goodness of fit indices of one, two and three factor models were compared with those of a unidimensional model specifying response bias on the NP items, using structural equation modelling (SEM. The hypotheses were (1 the variance of the responses would be significantly higher for NP items than for PP items because of response bias, and (2 that the modelling of response bias would provide the best fit for the data. Results Consistent with previous reports, EFA suggested a two-factor solution dividing the items into NP and PP items. The variance of responses to the NP items was substantially and significantly higher than for the PP items. The model incorporating response bias was the best fit for the data on all indices (RMSEA = 0.068, 90%CL = 0.064, 0.073. Analysis of the frequency of responses suggests that the response bias derives from the ambiguity of the response options for the absence of negative mood states. Conclusion The data are consistent with the GHQ-12 being a unidimensional scale with a substantial degree of response bias for the negatively phrased items. Studies that report the GHQ-12 as multidimensional without taking this response bias into account risk interpreting the artefactual factor structure as denoting 'real' constructs
Final model independent result of DAMA/LIBRA-phase1
Energy Technology Data Exchange (ETDEWEB)
Bernabei, R.; D' Angelo, S.; Di Marco, A. [Universita di Roma ' ' Tor Vergata' ' , Dipartimento di Fisica, Rome (Italy); INFN, sez. Roma ' ' Tor Vergata' ' , Rome (Italy); Belli, P. [INFN, sez. Roma ' ' Tor Vergata' ' , Rome (Italy); Cappella, F.; D' Angelo, A.; Prosperi, D. [Universita di Roma ' ' La Sapienza' ' , Dipartimento di Fisica, Rome (Italy); INFN, sez. Roma, Rome (Italy); Caracciolo, V.; Castellano, S.; Cerulli, R. [INFN, Laboratori Nazionali del Gran Sasso, Assergi (Italy); Dai, C.J.; He, H.L.; Kuang, H.H.; Ma, X.H.; Sheng, X.D.; Wang, R.G. [Chinese Academy, IHEP, Beijing (China); Incicchitti, A. [INFN, sez. Roma, Rome (Italy); Montecchia, F. [INFN, sez. Roma ' ' Tor Vergata' ' , Rome (Italy); Universita di Roma ' ' Tor Vergata' ' , Dipartimento di Ingegneria Civile e Ingegneria Informatica, Rome (Italy); Ye, Z.P. [Chinese Academy, IHEP, Beijing (China); University of Jing Gangshan, Jiangxi (China)
2013-12-15
The results obtained with the total exposure of 1.04 ton x yr collected by DAMA/LIBRA-phase1 deep underground at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N. during 7 annual cycles (i.e. adding a further 0.17 ton x yr exposure) are presented. The DAMA/LIBRA-phase1 data give evidence for the presence of Dark Matter (DM) particles in the galactic halo, on the basis of the exploited model independent DM annual modulation signature by using highly radio-pure NaI(Tl) target, at 7.5{sigma} C.L. Including also the first generation DAMA/NaI experiment (cumulative exposure 1.33 ton x yr, corresponding to 14 annual cycles), the C.L. is 9.3{sigma} and the modulation amplitude of the single-hit events in the (2-6) keV energy interval is: (0.0112{+-}0.0012) cpd/kg/keV; the measured phase is (144{+-}7) days and the measured period is (0.998{+-}0.002) yr, values well in agreement with those expected for DM particles. No systematic or side reaction able to mimic the exploited DM signature has been found or suggested by anyone over more than a decade. (orig.)
Infrared thermography for CFRP inspection: computational model and experimental results
Fernandes, Henrique C.; Zhang, Hai; Morioka, Karen; Ibarra-Castanedo, Clemente; López, Fernando; Maldague, Xavier P. V.; Tarpani, José R.
2016-05-01
Infrared Thermography (IRT) is a well-known Non-destructive Testing (NDT) technique. In the last decades, it has been widely applied in several fields including inspection of composite materials (CM), specially the fiber-reinforced polymer matrix ones. Consequently, it is important to develop and improve efficient NDT techniques to inspect and assess the quality of CM parts in order to warranty airworthiness and, at the same time, reduce costs of airline companies. In this paper, active IRT is used to inspect carbon fiber-reinforced polymer (CFRP) at laminate with artificial inserts (built-in sample) placed on different layers prior to the manufacture. Two optical active IRT are used. The first is pulsed thermography (PT) which is the most widely utilized IRT technique. The second is a line-scan thermography (LST) technique: a dynamic technique, which can be employed for the inspection of materials by heating a component, line-by-line, while acquiring a series of thermograms with an infrared camera. It is especially suitable for inspection of large parts as well as complex shaped parts. A computational model developed using COMSOL Multiphysics® was used in order to simulate the inspections. Sequences obtained from PT and LST were processed using principal component thermography (PCT) for comparison. Results showed that it is possible to detect insertions of different sizes at different depths using both PT and LST IRT techniques.
Testing and modeling non-normality within the one-factor model
Molenaar, D.; Dolan, C.V.; Verhelst, N.D.
2010-01-01
Maximum likelihood estimation in the one-factor model is based on the assumption of multivariate normality for the observed data. This general distributional assumption implies three specific assumptions for the parameters in the one-factor model: the common factor has a normal distribution; the res
Testing and modeling non-normality within the one-factor model
Molenaar, D.; Dolan, C.V.; Verhelst, N.D.
2010-01-01
Maximum likelihood estimation in the one-factor model is based on the assumption of multivariate normality for the observed data. This general distributional assumption implies three specific assumptions for the parameters in the one-factor model: the common factor has a normal distribution; the
Kolh, Philippe; Comté, Laetitia; Tchana-Sato, Vincent; Honoré, Charles; Kerzmann, Arnaud; Mauer, M.; Limet, Raymond
2006-01-01
Aims To assess risk factors for early and late outcome after concurrent carotid endarterectomy (CEA) and coronary artery bypass grafting (CABG). Methods and results Records of all 311 consecutive patients having concurrent CEA and CABG from 1989 to 2002 were reviewed, and follow-up obtained (100% complete). In the group (mean age 67 years; 74% males), 62% had triple-vessel disease, 57% unstable angina, 31% left main coronary stenosis, 19% congestive heart failure, and 35% either a history of ...
Spin-1 Ising model on tetrahedron recursive lattices: Exact results
Jurčišinová, E.; Jurčišin, M.
2016-11-01
We investigate the ferromagnetic spin-1 Ising model on the tetrahedron recursive lattices. An exact solution of the model is found in the framework of which it is shown that the critical temperatures of the second order phase transitions of the model are driven by a single equation simultaneously on all such lattices. It is also shown that this general equation for the critical temperatures is equivalent to the corresponding polynomial equation for the model on the tetrahedron recursive lattice with arbitrary given value of the coordination number. The explicit form of these polynomial equations is shown for the lattices with the coordination numbers z = 6, 9, and 12. In addition, it is shown that the thermodynamic properties of all possible physical phases of the model are also completely driven by the corresponding single equations simultaneously on all tetrahedron recursive lattices. In this respect, the spontaneous magnetization, the free energy, the entropy, and the specific heat of the model are studied in detail.
Droplet Reaction and Evaporation of Agents Model (DREAM). Glass model results; Sand model plans
Hin, A.R.T.
2006-01-01
The Agent Fate Program is generating an extensive set of quality agent fate data which is being used to develop highly accurate secondary evaporation predictive models. Models are being developed that cover a wide range of traditional chemical warfare agents deposited onto surfaces routinely found o
Continuous utility factor in segregation models: a few surprises
Roy, Parna
2015-01-01
We consider the constrained Schelling model of social segregation which allows non-local jumps of the agents. In the present study, the utility factor u is defined in a way such that it can take continuous values and depends on the tolerance threshold as well as fraction of unlike neighbours. Two models are proposed: in model A the jump probability is determined by the sign of u only which makes it equivalent to the discrete model. In model B the actual values of u are considered. Model A and model B are shown to differ drastically as far as segregation behaviour and phase transitions are concerned. The constrained model B turns out to be as efficient as the unconstrained discrete model, if not more. In addition, we also consider a few other dynamical aspects which have not been studied in segregation models earlier.
Institute of Scientific and Technical Information of China (English)
张晓丽; 覃亦伟; 赵晓勇
2014-01-01
Flt-1 2ml,21%O2 cultivation in the box;oxygen pressure group C:1%O2 oxygen pressure cultivation in the box;D group:50ng/ml sFlt-1 2ml,1%O2 oxygen pressure cultivation in the box) . ELISA method to detect pregnant rat plasma sFlt-1 level;Flow cytometry technique to detect cell apoptosis;Western blot method to detect apoptosis related proteins Bax,Bcl-2 and Caspase 3 expression. Results:In the control group and model group PE plasma sFlt-1 level, systolic pressure,diastolic blood pressure and urine protein,the difference was statistically sig-nificant ( P<0 . 01 );PE model is compared between way and compared with the control group (3. 95%),the difference was statistically significant (P<0. 01),group B and group C,in con-trast,there are significant difference (P<0. 05). Compared with control group,model group PE cells and promote apoptosis proteins Bax raised obviously,the Bcl-2 significantly lowered,sup-pression of apoptosis protein apoptosis perform protein Caspase 3 expression;Comparing two PE model group,the difference had statistical significance (P<0. 05). Conclusion:sFlt - 1 and anoxic factors closely associated with excessive PE sertoli cell apoptosis,both promote the devel-opment of PE.
Iguchi, Junta; Watanabe, Yuya; Kimura, Misaka; Fujisawa, Yoshihiko; Hojo, Tatsuya; Yuasa, Yasuhiro; Higashi, Shinsuke; Kuzuhara, Kenji
2016-12-01
Iguchi, J, Watanabe, Y, Kimura, M, Fujisawa, Y, Hojo, T, Yuasa, Y, Higashi, S, and Kuzuhara, K. Risk factors for injury among Japanese collegiate players of American football based on performance test results. J Strength Cond Res 30(12): 3405-3411, 2016-The purpose of this study was to identify how risk factors for injury during American football are related to players' physical strength as determined using typical performance tests. One hundred 53 Japanese collegiate players of American football were recruited for this study. Eight potential risk factors were evaluated: position (skill vs. lineman), body mass index, back squat one-repetition maximum, vertical jump height, power, height, body weight, and previous injury. Using multivariate Cox regression, we examined how these factors were associated with knee sprain, ankle sprain, and hamstring strain. We recorded 63 injuries (17 knee sprains, 23 ankle sprains, and 23 hamstring strains). Players with higher power were at significantly greater risk for knee sprains (p = 0.04), those with low power had a significantly higher incidence of ankle sprain (p = 0.01), and vertical jump height was a significant predictor of hamstring strain (p = 0.02). We identified several independent predictors of injuries associated with American football. Our findings may contribute to the development of effective screening tests and prevention exercises.
Yan, Hui; Cui, Guo-Qing; Wang, Jian-Quan; Yin, Yu; Tian, De-Xiang; Ao, Ying-Fang
2011-07-01
To evaluate retrospectively the results of arthroscopic Bankart repair using suture anchors for recurrent anterior shoulder dislocation with a minimum 1-year follow-up and to assess risk factors for recurrence. From March 2002 to March 2010, 259 patients with recurrent anterior shoulder dislocation underwent arthroscopic Bankart repair with suture anchors. And 188 patients (50 athletes, 138 nonathletes) were available for follow-up. The mean age at the time of surgery was 25.3 years (range, 13 - 58 years). The mean follow-up was 38.6 months (range, 12 - 110 months). All of the 188 patients were evaluated preoperatively and postoperatively with the American Shoulder and Elbow Society (ASES) shoulder score and Rowe score system. The rate of recurrent instability, range of motion, and risk factors for postoperative recurrence were evaluated. The ASES score was 72.6 preoperatively, and Rowe score was 33.4. The ASES scores improved significantly to 91.9 postoperatively (P Bankart lesion, presence of a superior labrum, anterior and posterior tear, presence of posterior or inferior labrum lesion, presence of rotator cuff tear, ligamentous laxity and rotator interval closure did not influence the recurrence rate (P > 0.05). Arthroscopic Bankart repair is a good option for the treatment of recurrent anterior shoulder dislocation. Identification of risk factors for recurrence allows for consideration of open stabilization. In the series, patients under age 20 and athlete patients are the most important risk factors for recurrence.
Effect of geometry of rice kernels on drying modeling results
Geometry of rice grain is commonly represented by sphere, spheroid or ellipsoid shapes in the drying models. Models using simpler shapes are easy to solve mathematically, however, deviation from the true grain shape might lead to large errors in predictions of drying characteristics such as, moistur...
Urban traffic noise assessment by combining measurement and model results
Eerden, F.J.M. van der; Graafland, F.; Wessels, P.W.; Basten, T.G.H.
2013-01-01
A model based monitoring system is applied on a local scale in an urban area to obtain a better understanding of the traffic noise situation. The system consists of a scalable sensor network and an engineering model. A better understanding is needed to take appropriate and cost efficient measures,
Periodic Integration: Further Results on Model Selection and Forecasting
Ph.H.B.F. Franses (Philip Hans); R. Paap (Richard)
1996-01-01
textabstractThis paper considers model selection and forecasting issues in two closely related models for nonstationary periodic autoregressive time series [PAR]. Periodically integrated seasonal time series [PIAR] need a periodic differencing filter to remove the stochastic trend. On the other
Factors affecting results of lymph node dissection in patients with skin Melanoma, 1987-92
Directory of Open Access Journals (Sweden)
Mir M
1998-08-01
Full Text Available In this paper, factors affecting the result of prophylactic lymph node dissection in 125 patients with skin melanoma during the period between 1987-1992 in the cancer institute were evaluated and prognostic parameters ascertained. The result showed prevalence of head and neck melanoma in men were two times more than in women with a preponderance of regional and lymphatic recurrence. Majority of patients presented with advanced clark levels (76.8 Pct. Clinical and histologic evaluation of the regional lymph nodes failed to show any meaningful relation.
Modelled and Observed Diurnal SST Signals: "SSTDV:R.EX.-IM.A.M." Project Preliminary Results
DEFF Research Database (Denmark)
Karagali, Ioanna; Høyer, Jacob; LeBorgne, Pierre
2013-01-01
This study presents some of the preliminary results from the ESA Support To Science Element (STSE) funded project on the Diurnal Variability of the Sea Surface Temperature, regarding its Regional Extend and Implications in Atmospheric Modelling (SSTDV:R.EX.–IM.A.M.). During this phase...... of the project, the focus is on the regional extend of diurnal variability. Particularly, extensive sensitivity tests regarding the definition of SSTfound fields show that using only quality 5 SEVIRI data results in warmer foundation fields SSTfound while there is an added ∼0.2 K variability when using multi...... Ocean Turbulence Model (GOTM) is applied. Preliminary results show that the initial temperature profiles may give a warmer start-up in the model while the light extinction scheme is a controlling factor for the amplitude and vertical extend of the daily signal....
Latent Fundamentals Arbitrage with a Mixed Effects Factor Model
Directory of Open Access Journals (Sweden)
Andrei Salem Gonçalves
2012-09-01
Full Text Available We propose a single-factor mixed effects panel data model to create an arbitrage portfolio that identifies differences in firm-level latent fundamentals. Furthermore, we show that even though the characteristics that affect returns are unknown variables, it is possible to identify the strength of the combination of these latent fundamentals for each stock by following a simple approach using historical data. As a result, a trading strategy that bought the stocks with the best fundamentals (strong fundamentals portfolio and sold the stocks with the worst ones (weak fundamentals portfolio realized significant risk-adjusted returns in the U.S. market for the period between July 1986 and June 2008. To ensure robustness, we performed sub period and seasonal analyses and adjusted for trading costs and we found further empirical evidence that using a simple investment rule, that identified these latent fundamentals from the structure of past returns, can lead to profit.
Electromagnetic form factors of the baryon octet in the perturbative chiral quark model
Cheedket, S; Gutsche, T; Faessler, A; Pumsa-ard, K; Yan, Y; Gutsche, Th.; Faessler, Amand
2002-01-01
We apply the perturbative chiral quark model at one loop to analyze the electromagnetic form factors of the baryon octet. The analytic expressions for baryon form factors, which are given in terms of fundamental parameters of low-energy pion-nucleon physics(weak pion decay constant, axial nucleon coupling, strong pion-nucleon form factor), and the numerical results for baryon magnetic moments, charge and magnetic radii are presented. Our results are in good agreement with experimental data.
Results from modeling and simulation of chemical downstream etch systems
Energy Technology Data Exchange (ETDEWEB)
Meeks, E.; Vosen, S.R.; Shon, J.W.; Larson, R.S.; Fox, C.A.; Buchenauer
1996-05-01
This report summarizes modeling work performed at Sandia in support of Chemical Downstream Etch (CDE) benchmark and tool development programs under a Cooperative Research and Development Agreement (CRADA) with SEMATECH. The Chemical Downstream Etch (CDE) Modeling Project supports SEMATECH Joint Development Projects (JDPs) with Matrix Integrated Systems, Applied Materials, and Astex Corporation in the development of new CDE reactors for wafer cleaning and stripping processes. These dry-etch reactors replace wet-etch steps in microelectronics fabrication, enabling compatibility with other process steps and reducing the use of hazardous chemicals. Models were developed at Sandia to simulate the gas flow, chemistry and transport in CDE reactors. These models address the essential components of the CDE system: a microwave source, a transport tube, a showerhead/gas inlet, and a downstream etch chamber. The models have been used in tandem to determine the evolution of reactive species throughout the system, and to make recommendations for process and tool optimization. A significant part of this task has been in the assembly of a reasonable set of chemical rate constants and species data necessary for successful use of the models. Often the kinetic parameters were uncertain or unknown. For this reason, a significant effort was placed on model validation to obtain industry confidence in the model predictions. Data for model validation were obtained from the Sandia Molecular Beam Mass Spectrometry (MBMS) experiments, from the literature, from the CDE Benchmark Project (also part of the Sandia/SEMATECH CRADA), and from the JDP partners. The validated models were used to evaluate process behavior as a function of microwave-source operating parameters, transport-tube geometry, system pressure, and downstream chamber geometry. In addition, quantitative correlations were developed between CDE tool performance and operation set points.
MODELING OF ENTERPRISE STATUS ON BASIS OF QUESTIONNAIRE RESULTS
Directory of Open Access Journals (Sweden)
N. Busniuk
2012-01-01
Full Text Available The paper considers two approaches for an evaluation of a current society status considered which can be represented by an enterprise, a region, a social group etc. The evaluation has been carried out on the basis of questionnaire. The questionnaire contains a list of factors, and a respondent makes marks which reflect his/her personal opinion pertaining to rate influence of every factor on the current situation. While applying methods of a fuzzy-set theory the respondent’s opinion (questionnaire content has been transformed in numerical value Z which serves for determination of the current status rate (an investigated problem rating in the society.The first approach. All the factors are equivalent and N respondents are involved in questionnaire campaign. (The respondents can be represented by enterprise personnel, inhabitants of a territory, representatives of social group etc.The second approach. The factors are inadequate, the questionnaire data is entered by an expert (one respondent.
A Two-Factor Autoregressive Moving Average Model Based on Fuzzy Fluctuation Logical Relationships
Directory of Open Access Journals (Sweden)
Shuang Guan
2017-10-01
Full Text Available Many of the existing autoregressive moving average (ARMA forecast models are based on one main factor. In this paper, we proposed a new two-factor first-order ARMA forecast model based on fuzzy fluctuation logical relationships of both a main factor and a secondary factor of a historical training time series. Firstly, we generated a fluctuation time series (FTS for two factors by calculating the difference of each data point with its previous day, then finding the absolute means of the two FTSs. We then constructed a fuzzy fluctuation time series (FFTS according to the defined linguistic sets. The next step was establishing fuzzy fluctuation logical relation groups (FFLRGs for a two-factor first-order autoregressive (AR(1 model and forecasting the training data with the AR(1 model. Then we built FFLRGs for a two-factor first-order autoregressive moving average (ARMA(1,m model. Lastly, we forecasted test data with the ARMA(1,m model. To illustrate the performance of our model, we used real Taiwan Stock Exchange Capitalization Weighted Stock Index (TAIEX and Dow Jones datasets as a secondary factor to forecast TAIEX. The experiment results indicate that the proposed two-factor fluctuation ARMA method outperformed the one-factor method based on real historic data. The secondary factor may have some effects on the main factor and thereby impact the forecasting results. Using fuzzified fluctuations rather than fuzzified real data could avoid the influence of extreme values in historic data, which performs negatively while forecasting. To verify the accuracy and effectiveness of the model, we also employed our method to forecast the Shanghai Stock Exchange Composite Index (SHSECI from 2001 to 2015 and the international gold price from 2000 to 2010.
A structural dynamic factor model for the effects of monetary policy estimated by the EM algorithm
DEFF Research Database (Denmark)
Bork, Lasse
This paper applies the maximum likelihood based EM algorithm to a large-dimensional factor analysis of US monetary policy. Specifically, economy-wide effects of shocks to the US federal funds rate are estimated in a structural dynamic factor model in which 100+ US macroeconomic and financial time...... series are driven by the joint dynamics of the federal funds rate and a few correlated dynamic factors. This paper contains a number of methodological contributions to the existing literature on data-rich monetary policy analysis. Firstly, the identification scheme allows for correlated factor dynamics...... as opposed to the orthogonal factors resulting from the popular principal component approach to structural factor models. Correlated factors are economically more sensible and important for a richer monetary policy transmission mechanism. Secondly, I consider both static factor loadings as well as dynamic...
A structural dynamic factor model for the effects of monetary policy estimated by the EM algorithm
DEFF Research Database (Denmark)
Bork, Lasse
This paper applies the maximum likelihood based EM algorithm to a large-dimensional factor analysis of US monetary policy. Specifically, economy-wide effects of shocks to the US federal funds rate are estimated in a structural dynamic factor model in which 100+ US macroeconomic and financial time...... series are driven by the joint dynamics of the federal funds rate and a few correlated dynamic factors. This paper contains a number of methodological contributions to the existing literature on data-rich monetary policy analysis. Firstly, the identification scheme allows for correlated factor dynamics...... as opposed to the orthogonal factors resulting from the popular principal component approach to structural factor models. Correlated factors are economically more sensible and important for a richer monetary policy transmission mechanism. Secondly, I consider both static factor loadings as well as dynamic...
Strokal, Maryna; Kroeze, Carolien; Wang, Mengru; Bai, Zhaohai; Ma, Lin
2016-08-15
Chinese agriculture has been developing fast towards industrial food production systems that discharge nutrient-rich wastewater into rivers. As a result, nutrient export by rivers has been increasing, resulting in coastal water pollution. We developed a Model to Assess River Inputs of Nutrients to seAs (MARINA) for China. The MARINA Nutrient Model quantifies river export of nutrients by source at the sub-basin scale as a function of human activities on land. MARINA is a downscaled version for China of the Global NEWS-2 (Nutrient Export from WaterSheds) model with an improved approach for nutrient losses from animal production and population. We use the model to quantify dissolved inorganic and organic nitrogen (N) and phosphorus (P) export by six large rivers draining into the Bohai Gulf (Yellow, Hai, Liao), Yellow Sea (Yangtze, Huai) and South China Sea (Pearl) in 1970, 2000 and 2050. We addressed uncertainties in the MARINA Nutrient model. Between 1970 and 2000 river export of dissolved N and P increased by a factor of 2-8 depending on sea and nutrient form. Thus, the risk for coastal eutrophication increased. Direct losses of manure to rivers contribute to 60-78% of nutrient inputs to the Bohai Gulf and 20-74% of nutrient inputs to the other seas in 2000. Sewage is an important source of dissolved inorganic P, and synthetic fertilizers of dissolved inorganic N. Over half of the nutrients exported by the Yangtze and Pearl rivers originated from human activities in downstream and middlestream sub-basins. The Yellow River exported up to 70% of dissolved inorganic N and P from downstream sub-basins and of dissolved organic N and P from middlestream sub-basins. Rivers draining into the Bohai Gulf are drier, and thus transport fewer nutrients. For the future we calculate further increases in river export of nutrients. The MARINA Nutrient model quantifies the main sources of coastal water pollution for sub-basins. This information can contribute to formulation of
A receptor model for urban aerosols based on oblique factor analysis
DEFF Research Database (Denmark)
Keiding, Kristian; Sørensen, Morten S.; Pind, Niels
1987-01-01
A procedure is outlined for the construction of receptor models of urban aerosols, based on factor analysis. The advantage of the procedure is that the covariation of source impacts is included in the construction of the models. The results are compared with results obtained by other receptor-modelling...... procedures. It was found that procedures based on correlating sources were physically sound as well as in mutual agreement. Procedures based on non-correlating sources were found to generate physically obscure models....
Support for the 7-factor hybrid model of PTSD in a community sample.
Seligowski, Antonia V; Orcutt, Holly K
2016-03-01
Research suggests that 4-factor models of posttraumatic stress disorder (PTSD) may be improved upon by the addition of novel factors, such as Dysphoric Arousal, Externalizing Behaviors, and Anhedonia. However, a novel 7-factor hybrid model has demonstrated superior fit in veteran and undergraduate samples. The current study sought to replicate this finding in a trauma-exposed community sample and examined relations with positive (PA) and negative affect (NA). Participants included 403 adults (M(age) = 37.75) recruited through Amazon's MTurk. PTSD was measured using the PTSD Checklist-5 (PCL-5). Confirmatory factor analyses were conducted in Mplus. The 7-factor hybrid model demonstrated good fit: CFI = .96, TLI = .95, RMSEA = .06 (90% CI [.05, .07]), SRMR = .03. This model was superior to the 5- and 6-factor models. All factors demonstrated significant relations with PA and NA, the largest of which were the Externalizing Behaviors (with NA) and Anhedonia (with PA) factors. Results provide support for the 7-factor hybrid model of PTSD using the PCL-5 in a community sample. Findings replicate previous research suggesting that PTSD is highly related to NA, which has been purported as an underlying dimension of PTSD. It is recommended that future research use clinical measures to further examine the hybrid model. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
Towards an Accurate Performance Modeling of Parallel SparseFactorization
Energy Technology Data Exchange (ETDEWEB)
Grigori, Laura; Li, Xiaoye S.
2006-05-26
We present a performance model to analyze a parallel sparseLU factorization algorithm on modern cached-based, high-end parallelarchitectures. Our model characterizes the algorithmic behavior bytakingaccount the underlying processor speed, memory system performance, aswell as the interconnect speed. The model is validated using theSuperLU_DIST linear system solver, the sparse matrices from realapplications, and an IBM POWER3 parallel machine. Our modelingmethodology can be easily adapted to study performance of other types ofsparse factorizations, such as Cholesky or QR.
Wave-current interactions: model development and preliminary results
Mayet, Clement; Lyard, Florent; Ardhuin, Fabrice
2013-04-01
The coastal area concentrates many uses that require integrated management based on diagnostic and predictive tools to understand and anticipate the future of pollution from land or sea, and learn more about natural hazards at sea or activity on the coast. The realistic modelling of coastal hydrodynamics needs to take into account various processes which interact, including tides, surges, and sea state (Wolf [2008]). These processes act at different spatial scales. Unstructured-grid models have shown the ability to satisfy these needs, given that a good mesh resolution criterion is used. We worked on adding a sea state forcing in a hydrodynamic circulation model. The sea state model is the unstructured version of WAVEWATCH III c (Tolman [2008]) (which version is developed at IFREMER, Brest (Ardhuin et al. [2010]) ), and the hydrodynamic model is the 2D barotropic module of the unstructured-grid finite element model T-UGOm (Le Bars et al. [2010]). We chose to use the radiation stress approach (Longuet-Higgins and Stewart [1964]) to represent the effect of surface waves (wind waves and swell) in the barotropic model, as previously done by Mastenbroek et al. [1993]and others. We present here some validation of the model against academic cases : a 2D plane beach (Haas and Warner [2009]) and a simple bathymetric step with analytic solution for waves (Ardhuin et al. [2008]). In a second part we present realistic application in the Ushant Sea during extreme event. References Ardhuin, F., N. Rascle, and K. Belibassakis, Explicit wave-averaged primitive equations using a generalized Lagrangian mean, Ocean Modelling, 20 (1), 35-60, doi:10.1016/j.ocemod.2007.07.001, 2008. Ardhuin, F., et al., Semiempirical Dissipation Source Functions for Ocean Waves. Part I: Definition, Calibration, and Validation, J. Phys. Oceanogr., 40 (9), 1917-1941, doi:10.1175/2010JPO4324.1, 2010. Haas, K. A., and J. C. Warner, Comparing a quasi-3D to a full 3D nearshore circulation model: SHORECIRC and
Directory of Open Access Journals (Sweden)
Vassiliki Tsiantou
2010-08-01
Full Text Available Vassiliki Tsiantou1, Polina Pantzou2, Elpida Pavi1, George Koulierakis2, John Kyriopoulos11Department of Health Economics, National School of Public Health, Athens, Greece; 2Department of Sociology, National School of Public Health, Athens, GreeceIntroduction: Although hypertension constitutes a major risk factor for cardiovascular morbidity and mortality, research on adherence to antihypertensive treatment has shown that at least 75% of patients are not adherent because of the combined demographic, organizational, psychological, and disease- and medication-related factors. This study aimed to elicit hypertensive patients’ beliefs on hypertension and antihypertensive treatment, and their role to adherence.Methods: Transcripts from semistructured interviews and focus groups were content analyzed to extract participants’ beliefs about hypertension and antihypertensive treatment, and attitudes toward patient–physician and patient–pharmacist relationships.Results: Hypertension was considered a very serious disease, responsible for stroke and myocardial infarction. Participants expressed concerns regarding the use of medicines and the adverse drug reactions. Previous experience with hypertension, fear of complications, systematic disease management, acceptance of hypertension as a chronic disease, incorporation of the role of the patient and a more personal relationship with the doctor facilitated adherence to the treatment. On the other hand, some patients discontinued treatment when they believed that they had controlled their blood pressure.Conclusion: Cognitive and communication factors affect medication adherence. Results could be used to develop intervention techniques to improve medication adherence.Keywords: hypertension, medication adherence, patient compliance, doctor–patient communication, antihypertensive medicine
Shinagawa, Kazuhiko; Ploplis, Victoria A; Castellino, Francis J
2009-05-01
Eosinophil counts in the bronchoalveolar lavage fluid of wild-type (WT) mice increased after ovalbumin (OVA) challenge, a response that was diminished in comparably challenged low-expressing coagulation factor VII (FVII(tTA/tTA)) mice. Levels of T helper type 2 (Th2) cytokines, IL-4, IL-5, and IL-13, and eosinophil-attracting chemokines, eotaxin and RANTES, were also lower in the OVA-challenged FVII(tTA/tTA) mice. Eosinophils purified from low-FVII mice underwent apoptosis at a faster rate compared with WT eosinophils, and eosinophil migration in response to eotaxin was reduced in eosinophils obtained from FVII(tTA/tTA) mice. Airway hyperresponsiveness and mucous layer thickness were reduced in OVA-treated FVII(tTA/tTA) mice, and addition of exogenous coagulation factor X (FX) enhanced mucin production in human epithelial NCI-H292 cells. Correspondingly, incubation of FX with NCI-H292 cells resulted in activated (a) FX production, suggesting that the components required for FX activation were present on NCI-H292 cells. These results demonstrate that FVIIa functions in the asthmatic response to an allergen by stimulating lung eosinophilia, airway hyperresponsiveness, and mucin production, this latter effect through its ability to activate FX in conjunction with tissue factor.
Saengprom, Narumon; Erawan, Waraporn; Damrongpanit, Suntonrapot; Sakulku, Jaruwan
2015-01-01
The purposes of this study were 1) Compare analytical thinking ability by testing the same sets of students 5 times 2) Develop and verify whether analytical thinking ability of students corresponds to second-order growth curve factors model. Samples were 1,093 eighth-grade students. The results revealed that 1) Analytical thinking ability scores…
Saengprom, Narumon; Erawan, Waraporn; Damrongpanit, Suntonrapot; Sakulku, Jaruwan
2015-01-01
The purposes of this study were 1) Compare analytical thinking ability by testing the same sets of students 5 times 2) Develop and verify whether analytical thinking ability of students corresponds to second-order growth curve factors model. Samples were 1,093 eighth-grade students. The results revealed that 1) Analytical thinking ability scores…
Some exact results on the Potts model partition function in a magnetic field
Energy Technology Data Exchange (ETDEWEB)
Chang, S-C [Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan (China); Shrock, Robert [C N Yang Institute for Theoretical Physics, Stony Brook University, Stony Brook, NY 11794 (United States)], E-mail: scchang@mail.ncku.edu.tw, E-mail: robert.shrock@stonybrook.edu
2009-09-25
We consider the Potts model in a magnetic field on an arbitrary graph G. Using a formula by F Y Wu for the partition function Z of this model as a sum over spanning subgraphs of G, we prove some properties of Z concerning factorization, monotonicity and zeros. A generalization of the Tutte polynomial is presented that corresponds to this partition function. In this context, we formulate and discuss two weighted graph-coloring problems. We also give a general structural result for Z for cyclic strip graphs.
Some exact results on the Potts model partition function in a magnetic field
Chang, Shu-Chiuan; Shrock, Robert
2009-09-01
We consider the Potts model in a magnetic field on an arbitrary graph G. Using a formula by F Y Wu for the partition function Z of this model as a sum over spanning subgraphs of G, we prove some properties of Z concerning factorization, monotonicity and zeros. A generalization of the Tutte polynomial is presented that corresponds to this partition function. In this context, we formulate and discuss two weighted graph-coloring problems. We also give a general structural result for Z for cyclic strip graphs.
Directory of Open Access Journals (Sweden)
Marizélia Rodrigues Costa Ribeiro
Full Text Available BACKGROUND: Screening for violence during pregnancy is one of the strategies for the prevention of abuse against women. Since violence is difficult to measure, it is necessary to validate questionnaires that can provide a good measure of the phenomenon. The present study analyzed the psychometric properties of the World Health Organization Violence Against Women (WHO VAW instrument for the measurement of violence against pregnant women. METHODS: Data from the Brazilian Ribeirão Preto and São Luís birth cohort studies (BRISA were used. The sample consisted of 1,446 pregnant women from São Luís and 1,378 from Ribeirão Preto, interviewed in 2010 and 2011. Thirteen variables were selected from a self-applied questionnaire. Confirmatory factor analysis was used to investigate whether violence is a uni-or-multidimensional construct consisting of psychological, physical and sexual dimensions. The mean-and-variance-adjusted weighted least squares estimator was used. Models were fitted separately for each city and a third model combining data from the two settings was also tested. Models suggested from modification indices were tested to determine whether changes in the WHO VAW model would produce a better fit. RESULTS: The unidimensional model did not show good fit (Root mean square error of approximation [RMSEA] = 0.060, p < 0.001 for the combined model. The multidimensional WHO VAW model showed good fit (RMSEA = 0.036, p = 0.999 for the combined model and standardized factor loadings higher than 0.70, except for the sexual dimension for SL (0.65. The models suggested by the modification indices with cross loadings measuring simultaneously physical and psychological violence showed a significantly better fit compared to the original WHO model (p < 0.001 for the difference between the model chi-squares. CONCLUSIONS: Violence is a multidimensional second-order construct consisting of psychological, physical and sexual dimensions. The WHO VAW
Box photosynthesis modeling results for WRF/CMAQ LSM
U.S. Environmental Protection Agency — Box Photosynthesis model simulations for latent heat and ozone at 6 different FLUXNET sites. This dataset is associated with the following publication: Ran, L., J....
Review of the dWind Model Conceptual Results
Energy Technology Data Exchange (ETDEWEB)
Baring-Gould, Ian; Gleason, Michael; Preus, Robert; Sigrin, Ben
2015-09-16
This presentation provides an overview of the dWind model, including its purpose, background, and current status. Baring-Gould presented this material as part of the September 2015 WINDExchange webinar.
Some Econometric Results for the Blanchard-Watson Bubble Model
DEFF Research Database (Denmark)
Johansen, Soren; Lange, Theis
The purpose of the present paper is to analyse a simple bubble model suggested by Blanchard and Watson. The model is defined by y(t) =s(t)¿y(t-1)+e(t), t=1,…,n, where s(t) is an i.i.d. binary variable with p=P(s(t)=1), independent of e(t) i.i.d. with mean zero and finite variance. We take ¿>1 so...
Parent Ratings of the Strengths and Difficulties Questionnaire: What Is the Optimum Factor Model?
Gomez, Rapson; Stavropoulos, Vasilis
2017-07-01
To date, at least 12 different models have been suggested for the Strengths and Difficulties Questionnaire (SDQ). The current study used confirmatory factor analysis to examine the relative support for these models. In all, 1,407 Malaysian parents completed SDQ ratings of their children (age range = 5-13 years). Although the findings showed some degree of support for all 12 models, there was most support for an oblique six-factor model that included the five SDQ domains (emotional problems, conduct problems, hyperactivity, peer problems, and low prosocial behavior) and a positive construal factor comprising all the 10 SDQ positive worded items. The original proposed five-factor oblique model also showed good fit. The implications of the findings for understanding the results of past studies of the structural models of the parent version of the SDQ, and for clinical and research practice involving the SDQ are discussed.
Results of the 2013 UT modeling benchmark obtained with models implemented in CIVA
Energy Technology Data Exchange (ETDEWEB)
Toullelan, Gwénaël; Raillon, Raphaële; Chatillon, Sylvain [CEA, LIST, 91191Gif-sur-Yvette (France); Lonne, Sébastien [EXTENDE, Le Bergson, 15 Avenue Emile Baudot, 91300 MASSY (France)
2014-02-18
The 2013 Ultrasonic Testing (UT) modeling benchmark concerns direct echoes from side drilled holes (SDH), flat bottom holes (FBH) and corner echoes from backwall breaking artificial notches inspected with a matrix phased array probe. This communication presents the results obtained with the models implemented in the CIVA software: the pencilmodel is used to compute the field radiated by the probe, the Kirchhoff approximation is applied to predict the response of FBH and notches and the SOV (Separation Of Variables) model is used for the SDH responses. The comparison between simulated and experimental results are presented and discussed.
Prognostic factors influencing the result of postoperative radiotherapy in endometrial carcinoma
Energy Technology Data Exchange (ETDEWEB)
Ki, Yong Kan; Kwon, Byung Hyun; Kim, Won Taek; Nam, Ji Ho; Yun, Man Su; Kim, Dong Won [Pusan National University School of Medicine, Busan (Korea, Republic of); Lee, Hyung Sik [Dong-A University School of Medicine, Busan (Korea, Republic of)
2006-06-15
This study was performed to determine the prognostic factors influencing relapse pattern, overall and disease-free survival in patients treated with postoperative radiotherapy for endometrial carcinoma. The records of 54 patients with endometrial adenocarcinoma treated postoperative radiotherapy at Pusan National University Hospital between April 1992 and May 2003 were reviewed retrospectively. Median age of the patients was 55 (range 35 {approx} 76). The distribution by surgical FIGO stages were 63.0% for 0 Stage I, 14.8% for Stage II, 22.2% for Stage III. All patients received postoperative external radiotherapy up to 41.4 {approx} 54 Gy (median: 50.4 Gy). Additional intravaginal brachytherapy was applied to 20 patients (37.0% of all). Median follow-up time was 35 months (5 {approx} 115 months). Significant factors of this study: histologic grade, lymphovascular space invasion and myometrial invasion depth were scored (GLM sore) and analyzed. Survival analysis was performed using Kaplan-Meier method. The log-rank test was used for univariate analysis and the Cox regression model for multivariate analysis. 5-year overall and disease-free survival rates were 87.7% and 87.1%, respectively. Prognostic factors related with overall and disease-free survival were histologic grade, lymphovascular space invasion and myometrial invasion according to the univariate analysis. According to the multivariate analysis, lymphovascular space invasion was associated with decreased disease-free survival. GLM score was a meaningful factor affecting overall and disease-free survival ({rho} = 0.0090, {rho} = 0.0073, respectively) and distant recurrence ({rho} = 0.0132), which was the sum of points of histologic grade, lymphovascular space invasion and myometrial invasion. Total failure rate was 11% with 6 patients. Relapse sites were 2 para-aortic lymph nodes, 2 lungs, a supraclavicular lymph node and a vagina. The prognosis in patients with endometrial carcinoma treated by
Complement factor B expression profile in a spontaneous uveitis model.
Zipplies, Johanna K; Kirschfink, Michael; Amann, Barbara; Hauck, Stefanie M; Stangassinger, Manfred; Deeg, Cornelia A
2010-12-01
Equine recurrent uveitis serves as a spontaneous model for human autoimmune uveitis. Unpredictable relapses and ongoing inflammation in the eyes of diseased horses as well as in humans lead to destruction of the retina and finally result in blindness. However, the molecular mechanisms leading to inflammation and retinal degeneration are not well understood. An initial screening for differentially regulated proteins in sera of uveitic cases compared to healthy controls revealed an increase of the alternative pathway complement component factor B in ERU cases. To determine the activation status of the complement system, sera were subsequently examined for complement split products. We could demonstrate a significant higher concentration of the activation products B/Ba, B/Bb, Bb neoantigen, iC3b and C3d in uveitic condition compared to healthy controls, whereas for C5b-9 no differences were detected. Additionally, we investigated complement activation directly in the retina by immunohistochemistry, since it is the main target organ of this autoimmune disease. Interestingly, infiltrating cells co-expressed activated factor Bb neoantigen, complement split product C3d as well as CD68, a macrophage marker. In this study, we could demonstrate activation of the complement system both systemically as well as in the eye, the target organ of spontaneous recurrent uveitis. Based on these novel findings, we postulate a novel role for macrophages in connection with complement synthesis at the site of inflammation.
Five-Factor Model personality profiles of drug users
Directory of Open Access Journals (Sweden)
Crum Rosa M
2008-04-01
Full Text Available Abstract Background Personality traits are considered risk factors for drug use, and, in turn, the psychoactive substances impact individuals' traits. Furthermore, there is increasing interest in developing treatment approaches that match an individual's personality profile. To advance our knowledge of the role of individual differences in drug use, the present study compares the personality profile of tobacco, marijuana, cocaine, and heroin users and non-users using the wide spectrum Five-Factor Model (FFM of personality in a diverse community sample. Method Participants (N = 1,102; mean age = 57 were part of the Epidemiologic Catchment Area (ECA program in Baltimore, MD, USA. The sample was drawn from a community with a wide range of socio-economic conditions. Personality traits were assessed with the Revised NEO Personality Inventory (NEO-PI-R, and psychoactive substance use was assessed with systematic interview. Results Compared to never smokers, current cigarette smokers score lower on Conscientiousness and higher on Neuroticism. Similar, but more extreme, is the profile of cocaine/heroin users, which score very high on Neuroticism, especially Vulnerability, and very low on Conscientiousness, particularly Competence, Achievement-Striving, and Deliberation. By contrast, marijuana users score high on Openness to Experience, average on Neuroticism, but low on Agreeableness and Conscientiousness. Conclusion In addition to confirming high levels of negative affect and impulsive traits, this study highlights the links between drug use and low Conscientiousness. These links provide insight into the etiology of drug use and have implications for public health interventions.
Fuzzy MCDM Model for Risk Factor Selection in Construction Projects
Directory of Open Access Journals (Sweden)
Pejman Rezakhani
2012-11-01
Full Text Available Risk factor selection is an important step in a successful risk management plan. There are many risk factors in a construction project and by an effective and systematic risk selection process the most critical risks can be distinguished to have more attention. In this paper through a comprehensive literature survey, most significant risk factors in a construction project are classified in a hierarchical structure. For an effective risk factor selection, a modified rational multi criteria decision making model (MCDM is developed. This model is a consensus rule based model and has the optimization property of rational models. By applying fuzzy logic to this model, uncertainty factors in group decision making such as experts` influence weights, their preference and judgment for risk selection criteria will be assessed. Also an intelligent checking process to check the logical consistency of experts` preferences will be implemented during the decision making process. The solution inferred from this method is in the highest degree of acceptance of group members. Also consistency of individual preferences is checked by some inference rules. This is an efficient and effective approach to prioritize and select risks based on decisions made by group of experts in construction projects. The applicability of presented method is assessed through a case study.
Preliminary results of a three-dimensional radiative transfer model
Energy Technology Data Exchange (ETDEWEB)
O`Hirok, W. [Univ. of California, Santa Barbara, CA (United States)
1995-09-01
Clouds act as the primary modulator of the Earth`s radiation at the top of the atmosphere, within the atmospheric column, and at the Earth`s surface. They interact with both shortwave and longwave radiation, but it is primarily in the case of shortwave where most of the uncertainty lies because of the difficulties in treating scattered solar radiation. To understand cloud-radiative interactions, radiative transfer models portray clouds as plane-parallel homogeneous entities to ease the computational physics. Unfortunately, clouds are far from being homogeneous, and large differences between measurement and theory point to a stronger need to understand and model cloud macrophysical properties. In an attempt to better comprehend the role of cloud morphology on the 3-dimensional radiation field, a Monte Carlo model has been developed. This model can simulate broadband shortwave radiation fluxes while incorporating all of the major atmospheric constituents. The model is used to investigate the cloud absorption anomaly where cloud absorption measurements exceed theoretical estimates and to examine the efficacy of ERBE measurements and cloud field experiments. 3 figs.
Reply: New results justify open discussion of alternative models
Newman, Andrew; Stein, Seth; Weber, John; Engeln, Joseph; Mao, Aitlin; Dixon, Timothy
A millennium ago, Jewish sages wrote that “the rivalry of scholars increases wisdom.” In contrast, Schweig et al. (Eos, this issue) demand that “great caution” be exercised in discussing alternatives to their model of high seismic hazard in the New Madrid seismic zone (NMSZ). We find this view surprising; we have no objection to their and their coworkers' extensive efforts promoting their model in a wide variety of public media, but see no reason not to explore a lower-hazard alternative based on both new data and reanalysis of data previously used to justify their model. In our view, the very purpose of collecting new data and reassessing existing data is to promote spirited testing and improvement of existing hypotheses. For New Madrid, such open reexamination seems scientifically appropriate, given the challenge of understanding intraplate earthquakes, and socially desirable because of the public policy implications.
Some Econometric Results for the Blanchard-Watson Bubble Model
DEFF Research Database (Denmark)
Johansen, Soren; Lange, Theis
The purpose of the present paper is to analyse a simple bubble model suggested by Blanchard and Watson. The model is defined by y(t) =s(t)¿y(t-1)+e(t), t=1,…,n, where s(t) is an i.i.d. binary variable with p=P(s(t)=1), independent of e(t) i.i.d. with mean zero and finite variance. We take ¿>1 so...... is whether a bubble model with infinite variance can create the long swings, or persistence, which are observed in many macro variables. We say that a variable is persistent if its autoregressive coefficient ¿(n) of y(t) on y(t-1), is close to one. We show that the estimator of ¿(n) converges to ¿p...
Gonzálvez, Alicia G; González Ureña, Ángel
2012-10-01
A laser spectroscopic technique is described that combines transmission and resonance-enhanced Raman inelastic scattering together with low laser power (view, a model for the Raman signal dependence on the sample thickness is also presented. Essentially, the model considers the sample to be homogeneous and describes the underlying physics using only three parameters: the Raman cross-section, the laser-radiation attenuation cross-section, and the Raman signal attenuation cross-section. The model was applied successfully to describe the sample-size dependence of the Raman signal in both β-carotene standards and carrot roots. The present technique could be useful for direct, fast, and nondestructive investigations in food quality control and analytical or physiological studies of animal and human tissues.
Directory of Open Access Journals (Sweden)
Viswanathan Arunachalam
2013-01-01
Full Text Available The classical models of single neuron like Hodgkin-Huxley point neuron or leaky integrate and fire neuron assume the influence of postsynaptic potentials to last till the neuron fires. Vidybida (2008 in a refreshing departure has proposed models for binding neurons in which the trace of an input is remembered only for a finite fixed period of time after which it is forgotten. The binding neurons conform to the behaviour of real neurons and are applicable in constructing fast recurrent networks for computer modeling. This paper develops explicitly several useful results for a binding neuron like the firing time distribution and other statistical characteristics. We also discuss the applicability of the developed results in constructing a modified hourglass network model in which there are interconnected neurons with excitatory as well as inhibitory inputs. Limited simulation results of the hourglass network are presented.
Fong, Ted C T; Ho, Rainbow T H; Wan, Adrian H Y; Siu, Pantha Joey C Y; Au-Yeung, Friendly S W
2015-10-01
The Positive and Negative Syndrome Scale (PANSS) is widely used for clinical assessment of symptoms in schizophrenia. Instead of the traditional pyramidal model, recent literature supports the pentagonal model for the dimensionality of the PANSS. The present study aimed to validate the consensus five-factor model of the PANSS and evaluate its convergent validity. Participants were 146 Chinese chronic schizophrenic patients who completed diagnostic interviews and cognitive assessments. Exploratory structural equation modeling (ESEM) was performed to investigate the dimensionality of the PANSS. Covariates (age, sex, and education level) and concurrent outcomes (perceived stress, memory, daily living functions, and motor deficits) were added in the ESEM model. The results supported the consensus 5-factor underlying structure, which comprised 20 items categorized into positive, negative, excitement, depression, and cognitive factors with acceptable reliability (α=.69-.85) and strong factor loadings (λ=.41-.93). The five factors, especially the cognitive factor, showed evident convergent validity with the covariates and concurrent outcomes. The results support the consensus five-factor structure of the PANSS as a robust measure of symptoms in schizophrenia. Future studies could explore the clinical and practical utility of the consensus five-factor model. Copyright © 2015 Elsevier Inc. All rights reserved.
Directory of Open Access Journals (Sweden)
Tycus Tse Tao Sun
2017-06-01
Full Text Available A retrospective review for enchondroma in the hand which had undergone operative treatment is presented. Twenty patients were treated operatively over a 10-year period. A total of 70% of the patients presented with pathological fracture. Enchondromas were most commonly located in the little finger (65% and proximal phalange (60%. Enchondromas presented with pathological fractures and were treated definitively after the fracture had healed, except for one patient with open reduction, internal fixation of fracture, and bone grafting. All 20 patients underwent curettage of the enchondroma. In the same operative occasion, 16 patients received bone grafting, three patients received bone substitutes, and one had received bone cement. Fourteen (70% of the patients suffered no major postoperative complications. Postoperative stiffness was encountered in seven patients. A secondary operation for relief of postoperative stiffness was performed in three patients. Factors were assessed for their risk of resulting in postoperative stiffness and occurrence of secondary operation. Factors included sex, age, pathological fracture, location of lesion, and preoperative stiffness. Only preoperative stiffness was a statistically significant risk factor contributing to postoperative stiffness and occurrence of a secondary operation.
Risk factors for Barrett's oesophagus and oesophageal adenocarcinoma: Results from the FINBAR study
Institute of Scientific and Technical Information of China (English)
Lesley A Anderson; RG Peter Watson; Seamus J Murphy; Brian T Johnston; Harry Comber; Jim Mc Guigan; John V Reynolds; Liam J Murray
2007-01-01
AIM: To investigate risk factors associated with Barrett's oesophagus and oesophageal adenocarcinoma.METHODS: This all-Ireland population-based case-control study recruited 224 Barrett's oesophagus patients, 227 oesophageal adenocarcinoma patients and 260 controls. All participants underwent a structured interview with information obtained about potential lifestyle and environmental risk factors.RESULTS: Gastro-oesophageal reflux was associated with Barrett's [OR 12.0 (95% CI 7.64-18.7)] and oesophageal adenocarcinoma [OR 3.48 (95% CI 2.25-5.41)]. Oesophageal adenocarcinoma patients were more likely than controls to be ex- or current smokers [OR 1.72 (95% CI 1.06-2.81) and OR 4.84 (95% CI 2.72-8.61) respectively] and to have a high body mass index [OR 2.69 (95% CI 1.62-4.46)]. No significant associations were observed between these risk factors and Barrett's oesophagus. Fruit but not vegetables were negatively associated with oesophageal adenocarcinoma [OR 0.50 (95% CI 0.30-0.86)].CONCLUSION: A high body mass index, a diet low in fruit and cigarette smoking may be involved in the progression from Barrett's oesophagus to oesophageal adenocarcinoma.
Janczarek, I; Bereznowski, A; Strzelec, K
2013-01-01
The aim of the study was to define the influence of the selected factors (gender, age, transportation time, riding distance and air temperature during the ride) on the cortisol secretion and finding a correlation between the hormone level and the horses' sport results (veterinary parameters and the ride route parameters). The research was performed on 38 Arabian pure breed horses taking part in the endurance rides. The cortisol level was measured with enzyme-immunological method in saliva samples, taken four times from each horse. In order to verify the differences between the mean results the repeated measures design was applied. The significance of the differences between the mean values was determined by the Tukey test. To evaluate the interrelations between the analysed attributes Pearson's correlation analysis was applied. The cortisol level at rest was not affected by any of the analysed factors. In case of other results, the most significant influence (P cortisol level was noted in mares, horses running the longest distances and at the highest temperatures. A significant increase in the cortisol level was noted when the ride distance was longer. There were no clear correlation between the adrenal cortex activity and the veterinary parameters at different riding speed. High cortisol concentration can negatively affect the heart rate (HR) by increasing it, but it can simultaneously stimulate the body to fight dehydration.
Directory of Open Access Journals (Sweden)
Mikhail Benet Rodríguez
2011-04-01
Full Text Available Chronic diseases are the leading causes of morbidity and mortality in Cuba, the monitoring of them is an important element to alert health care system on its evolution. The aim of this study was to describe the prevalence of four of the most important risk factors for these diseases during the preliminary data of the second survey of Cienfuegos CARMEN project, with emphasis on the differences with the first survey results. Method: Preliminary results of the second CARMEN survey are presented, corresponding to the first (847 cases measured integrally from a probabilitic and representative sample of the adult population of Cienfuegos City. Studied variables included: hypertension; obesity, measured by the body mass index, smoking and diabetes mellitus. Results: 33.7% of interviewed persons were smokers, slightly lower than the first measurement, obesity BMI> = 30 kg/m2 was 18.8%, almost 8% higher than the baseline survey, the arterial hypertension to 35.5% and diabetes mellitus to 6.8%, both well above the measurement of 2001-2002. Conclusions: the risk factors discussed show that the problem after improving over the past 10 years, and generally worsens the values are much higher than those observed during the first measurement CARMEN.
Some vaccination strategies for the SEIR epidemic model. Preliminary results
De la Sen, M; Alonso-Quesada, S
2011-01-01
This paper presents a vaccination-based control strategy for a SEIR (susceptible plus infected plus infectious plus removed populations) propagation disease model. The model takes into account the total population amounts as a refrain for the illness transmission since its increase makes more difficult contacts among susceptible and infected. The control objective is the asymptotically tracking of the removed-by-immunity population to the total population while achieving simultaneously the remaining population (i.e. susceptible plus infected plus infectious) to asymptotically tend to zero.
Results from Development of Model Specifications for Multifamily Energy Retrofits
Energy Technology Data Exchange (ETDEWEB)
Brozyna, K.
2012-08-01
Specifications, modeled after CSI MasterFormat, provide the trade contractors and builders with requirements and recommendations on specific building materials, components and industry practices that comply with the expectations and intent of the requirements within the various funding programs associated with a project. The goal is to create a greater level of consistency in execution of energy efficiency retrofits measures across the multiple regions a developer may work. IBACOS and Mercy Housing developed sample model specifications based on a common building construction type that Mercy Housing encounters.
Results From Development of Model Specifications for Multifamily Energy Retrofits
Energy Technology Data Exchange (ETDEWEB)
Brozyna, Kevin [IBACOS, Inc., Pittsburgh, PA (United States)
2012-08-01
Specifications, modeled after CSI MasterFormat, provide the trade contractors and builders with requirements and recommendations on specific building materials, components and industry practices that comply with the expectations and intent of the requirements within the various funding programs associated with a project. The goal is to create a greater level of consistency in execution of energy efficiency retrofits measures across the multiple regions a developer may work. IBACOS and Mercy Housing developed sample model specifications based on a common building construction type that Mercy Housing encounters.
Reumann, Marie K; Strachna, Olga; Yagerman, Sarah; Torrecilla, Daniel; Kim, Jihye; Doty, Stephen B; Lukashova, Lyudmila; Boskey, Adele L; Mayer-Kuckuk, Philipp
2011-10-01
Transcription factors that play a role in ossification during development are expected to participate in postnatal fracture repair since the endochondral bone formation that occurs in embryos is recapitulated during fracture repair. However, inherent differences exist between bone development and fracture repair, including a sudden disruption of tissue integrity followed by an inflammatory response. This raises the possibility that repair-specific transcription factors participate in bone healing. Here, we assessed the consequence of loss of early growth response gene 1 (EGR-1) on endochondral bone healing because this transcription factor has been shown to modulate repair in vascularized tissues. Model fractures were created in ribs of wild type (wt) and EGR-1(-/-) mice. Differences in tissue morphology and composition between these two animal groups were followed over 28 post fracture days (PFDs). In wt mice, bone healing occurred in healing phases characteristic of endochondral bone repair. A similar healing sequence was observed in EGR-1(-/-) mice but was impaired by alterations. A persistent accumulation of fibrin between the disconnected bones was observed on PFD7 and remained pronounced in the callus on PFD14. Additionally, the PFD14 callus was abnormally enlarged and showed increased deposition of mineralized tissue. Cartilage ossification in the callus was associated with hyper-vascularity and -proliferation. Moreover, cell deposits located in proximity to the callus within skeletal muscle were detected on PFD14. Despite these impairments, repair in EGR-1(-/-) callus advanced on PFD28, suggesting EGR-1 is not essential for healing. Together, this study provides genetic evidence that EGR-1 is a pleiotropic regulator of endochondral fracture repair. Copyright © 2011 Elsevier Inc. All rights reserved.
HIGH DIMENSIONAL COVARIANCE MATRIX ESTIMATION IN APPROXIMATE FACTOR MODELS.
Fan, Jianqing; Liao, Yuan; Mincheva, Martina
2011-01-01
The variance covariance matrix plays a central role in the inferential theories of high dimensional factor models in finance and economics. Popular regularization methods of directly exploiting sparsity are not directly applicable to many financial problems. Classical methods of estimating the covariance matrices are based on the strict factor models, assuming independent idiosyncratic components. This assumption, however, is restrictive in practical applications. By assuming sparse error covariance matrix, we allow the presence of the cross-sectional correlation even after taking out common factors, and it enables us to combine the merits of both methods. We estimate the sparse covariance using the adaptive thresholding technique as in Cai and Liu (2011), taking into account the fact that direct observations of the idiosyncratic components are unavailable. The impact of high dimensionality on the covariance matrix estimation based on the factor structure is then studied.
High-dimensional covariance matrix estimation in approximate factor models
Fan, Jianqing; Mincheva, Martina; 10.1214/11-AOS944
2012-01-01
The variance--covariance matrix plays a central role in the inferential theories of high-dimensional factor models in finance and economics. Popular regularization methods of directly exploiting sparsity are not directly applicable to many financial problems. Classical methods of estimating the covariance matrices are based on the strict factor models, assuming independent idiosyncratic components. This assumption, however, is restrictive in practical applications. By assuming sparse error covariance matrix, we allow the presence of the cross-sectional correlation even after taking out common factors, and it enables us to combine the merits of both methods. We estimate the sparse covariance using the adaptive thresholding technique as in Cai and Liu [J. Amer. Statist. Assoc. 106 (2011) 672--684], taking into account the fact that direct observations of the idiosyncratic components are unavailable. The impact of high dimensionality on the covariance matrix estimation based on the factor structure is then studi...
Matrix Factorizations for Local F-Theory Models
Omer, Harun
2016-01-01
I use matrix factorizations to describe branes at simple singularities as they appear in elliptic fibrations of local F-theory models. Each node of the corresponding Dynkin diagrams of the ADE-type singularities is associated with one indecomposable matrix factorization which can be deformed into one or more factorizations of lower rank. Branes with internal fluxes arise naturally as bound states of the indecomposable factorizations. Describing branes in such a way avoids the need to resolve singularities and encodes information which is neglected in conventional F-theory treatments. This paper aims to show how branes arising in local F-theory models around simple singularities can be described in this framework.
Game Factors and Game-Based Learning Design Model
Directory of Open Access Journals (Sweden)
Yen-Ru Shi
2015-01-01
Full Text Available How to design useful digital game-based learning is a topic worthy of discussion. Past research focused on specific game genres design, but it is difficult to use when the target game genre differs from the default genres used in the research. This study presents macrodesign concepts that elucidates 11 crucial game-design factors, including game goals, game mechanism, game fantasy, game value, interaction, freedom, narrative, sensation, challenges, sociality, and mystery. We clearly define each factor and analyze the relationships among the 11 factors to construct a game-based learning design model. Two application examples are analyzed to verify the usability of the model and the performance of these factors. It can assist educational game designers in developing interesting games.
Supplementary Material for: Factor Copula Models for Replicated Spatial Data
Krupskii, Pavel
2016-01-01
We propose a new copula model that can be used with replicated spatial data. Unlike the multivariate normal copula, the proposed copula is based on the assumption that a common factor exists and affects the joint dependence of all measurements of the process. Moreover, the proposed copula can model tail dependence and tail asymmetry. The model is parameterized in terms of a covariance function that may be chosen from the many models proposed in the literature, such as the Matérn model. For some choice of common factors, the joint copula density is given in closed form and therefore likelihood estimation is very fast. In the general case, one-dimensional numerical integration is needed to calculate the likelihood, but estimation is still reasonably fast even with large data sets. We use simulation studies to show the wide range of dependence structures that can be generated by the proposed model with different choices of common factors. We apply the proposed model to spatial temperature data and compare its performance with some popular geostatistics models.
Sarcopenia and its associated factors in Iranian older individuals: Results of SARIR study.
Hashemi, Rezvan; Shafiee, Gita; Motlagh, Ahmadreza Dorosty; Pasalar, Parvin; Esmailzadeh, Ahmad; Siassi, Fereydoun; Larijani, Bagher; Heshmat, Ramin
2016-01-01
Sarcopenia, an age- related loss of muscle mass, is a significant associating factor for functional impairment among older adults. The aim of this study was to investigate the prevalence of and associated factors for sarcopenia and severe sarcopenia among older adults in Iran. A total of 300 individuals aged over 55 years were randomly selected from the 6th district of Tehran, Iran, in 2011. Sarcopenia was defined according to the European Working Group on Sarcopenia in Older People (EWGSOP) algorithm. The skeletal muscle mass was assessed using DXA. Muscle strength and muscle performance were assessed according to hand grip strength and 4-m usual walking gait speed test. A logistic regression analysis was performed. The prevalence values of presarcopenia, sarcopenia, and severe sarcopenia were 52.7%, 20.7%, and 6%, in men and 25.3%, 15.3%, and 5.3% in women, respectively. The prevalence of sarcopenia was higher in men older than 75 years than women in the same age range (36.7% versus 20%, respectively). Using multiple logistic regression models, age, sex, smoking, and body mass index (BMI) were independently associated with different stages of sarcopenia. The prevalence of sarcopenia is high in Iranian older adults. The older age, male sex, smoking and lower BMI were independently associated with presarcopenia, sarcopenia and severe sarcopenia. Copyright © 2016. Published by Elsevier Ireland Ltd.
Risk factors for hip fracture. MEDOS study: results of the Toulouse Centre.
Ribot, C; Tremollieres, F; Pouilles, J M; Albarede, J L; Mansat, M; Utheza, G; Bonneu, M; Bonnissent, P; Ricoeur, C
1993-01-01
The development of preventive strategies for hip fractures requires better identification of risk factors. The MEDOS study was designed to study prospectively the incidence of hip fracture in 14 centres from six countries and characterise risk factors. At one centre (Toulouse), data were gathered from questionnaires completed by 386 cases of hip fracture aged over 50 years and 848 age- and sex-matched controls over a 12-month period. Of the 935 variables of the MEDOS questionnaire, 235, grouped into 56 items, were statistically analysed. Odds ratios (and 95% confidence intervals) were estimated for each variable from a multiple stepwise logistic regression model. The population comprised 19.2% men and 80.8% women, with a mean age of 80 +/- 8.8 years; 80% were living in an urban area and 76% with their family. Of the 17 significant variables, moderate excess weight and a high nutritional intake of calcium were associated with a decreased risk of hip fracture. Loss of autonomy, a higher height than normal (> 1SD), and a history of previous fractures significantly increased the risk of fracture. Interestingly, all these variables accounted for only 18% of the risk of hip fracture.
Determination of effective loss factors in reduced SEA models
Chimeno Manguán, M.; Fernández de las Heras, M. J.; Roibás Millán, E.; Simón Hidalgo, F.
2017-01-01
The definition of Statistical Energy Analysis (SEA) models for large complex structures is highly conditioned by the classification of the structure elements into a set of coupled subsystems and the subsequent determination of the loss factors representing both the internal damping and the coupling between subsystems. The accurate definition of the complete system can lead to excessively large models as the size and complexity increases. This fact can also rise practical issues for the experimental determination of the loss factors. This work presents a formulation of reduced SEA models for incomplete systems defined by a set of effective loss factors. This reduced SEA model provides a feasible number of subsystems for the application of the Power Injection Method (PIM). For structures of high complexity, their components accessibility can be restricted, for instance internal equipments or panels. For these cases the use of PIM to carry out an experimental SEA analysis is not possible. New methods are presented for this case in combination with the reduced SEA models. These methods allow defining some of the model loss factors that could not be obtained through PIM. The methods are validated with a numerical analysis case and they are also applied to an actual spacecraft structure with accessibility restrictions: a solar wing in folded configuration.
Directory of Open Access Journals (Sweden)
Lingineni Ravi K
2012-05-01
Full Text Available Abstract Background The purpose of this study was to investigate the association between Attention Deficit/Hyperactivity Disorder (ADHD and various factors using a representative sample of US children in a comprehensive manner. This includes variables that have not been previously studied such as watching TV/playing video games, computer usage, family member’s smoking, and participation in sports. Methods This was a cross-sectional study of 68,634 children, 5–17 years old, from the National Survey of Children’s Health (NSCH, 2007–2008. We performed bivariate and multivariate logistic regression analyses with ADHD classification as the response variable and the following explanatory variables: sex, race, depression, anxiety, body mass index, healthcare coverage, family structure, socio-economic status, family members’ smoking status, education, computer usage, watching television (TV/playing video games, participation in sports, and participation in clubs/organizations. Results Approximately 10% of the sample was classified as having ADHD. We found depression, anxiety, healthcare coverage, and male sex of child to have increased odds of being diagnosed with ADHD. One of the salient features of this study was observing a significant association between ADHD and variables such as TV usage, participation in sports, two-parent family structure, and family members’ smoking status. Obesity was not found to be significantly associated with ADHD, contrary to some previous studies. Conclusions The current study uncovered several factors associated with ADHD at the national level, including some that have not been studied earlier in such a setting. However, we caution that due to the cross-sectional and observational nature of the data, a cause and effect relationship between ADHD and the associated factors can not be deduced from this study. Future research on ADHD should take into consideration these factors, preferably through a
Directory of Open Access Journals (Sweden)
Mohammad Mostafa Zaman
2016-01-01
Full Text Available Background: Nationally representative data on noncommunicable disease (NCD risk factors are lacking in Bangladesh. This study was done to determine the prevalence of common risk factors for major NCDs among men and women of rural and urban areas of Bangladesh. Materials and Methods: This survey was done with 9,275 individuals aged 25 years or older randomly drawn from all over the country. Information on diet, physical activity, tobacco and alcohol, and treatment history for hypertension and diabetes were collected. Height, weight, waist circumference, and blood pressure (BP were measured. Results: There were 4,312 men and 4,963 women with the mean age of 42 years (standard deviation 13 years. Half of them (54% used tobacco in some form, <1% consumed alcohol within the past 30 days, 92% did not consume adequate fruit and vegetables (five servings or more, and 35% had low physical activity level [<600 metabolic equivalent (MET min per week]. Documented diabetes was found in 4% of the participants. Seventeen percent were overweight [body mass index (BMI ≥25 kg/m 2 and 21% had abdominal obesity (men ≥94, women ≥80 cm. Overall, 21% people had hypertension (blood pressure ≥140/90 mmHg or medication. Physical inactivity, alcohol intake, hypertension, obesity, and diabetes were more prevalent in urban areas, as opposed to tobacco. Tobacco intake showed a decreasing gradient, but hypertension, obesity, diabetes, and low physical activity showed an increasing gradient across the wealth quartiles. Conclusion: Risk factors are widely prevalent in Bangladeshi people across sexes and across both rural and urban areas of residences. NCD prevention through risk factor control, and early detection and treatment of hypertension and diabetes are warranted.
Some Results On The Modelling Of TSS Manufacturing Lines
Directory of Open Access Journals (Sweden)
Viorel MÎNZU
2000-12-01
Full Text Available This paper deals with the modelling of a particular class of manufacturing lines, governed by a decentralised control strategy so that they balance themselves. Such lines are known as “bucket brigades” and also as “TSS lines”, after their first implementation, at Toyota, in the 70’s. A first study of their behaviour was based upon modelling as stochastic dynamic systems, which emphasised, in the frame of the so-called “Normative Model”, a sufficient condition for self-balancing, that means for autonomous functioning at a steady production rate (stationary behaviour. Under some particular conditions, a simulation analysis of TSS lines could be made on non-linear block diagrams, showing that the state trajectories are piecewise continuous in between occurrences of certain discrete events, which determine their discontinuity. TSS lines may therefore be modelled as hybrid dynamic systems, more specific, with autonomous switching and autonomous impulses (jumps. A stability analysis of such manufacturing lines is allowed by modelling them as hybrid dynamic systems with discontinuous motions.
Proneurogenic Ligands Defined by Modeling Developing Cortex Growth Factor Communication Networks.
Yuzwa, Scott A; Yang, Guang; Borrett, Michael J; Clarke, Geoff; Cancino, Gonzalo I; Zahr, Siraj K; Zandstra, Peter W; Kaplan, David R; Miller, Freda D
2016-09-01
The neural stem cell decision to self-renew or differentiate is tightly regulated by its microenvironment. Here, we have asked about this microenvironment, focusing on growth factors in the embryonic cortex at a time when it is largely comprised of neural precursor cells (NPCs) and newborn neurons. We show that cortical NPCs secrete factors that promote their maintenance, while cortical neurons secrete factors that promote differentiation. To define factors important for these activities, we used transcriptome profiling to identify ligands produced by NPCs and neurons, cell-surface mass spectrometry to identify receptors on these cells, and computational modeling to integrate these data. The resultant model predicts a complex growth factor environment with multiple autocrine and paracrine interactions. We tested this communication model, focusing on neurogenesis, and identified IFNγ, Neurturin (Nrtn), and glial-derived neurotrophic factor (GDNF) as ligands with unexpected roles in promoting neurogenic differentiation of NPCs in vivo.
Electromagnetic form factors in a collective model of the nucleon
Bijker, R; Leviatan, A
1995-01-01
We study the electromagnetic form factors of the nucleon in a collective model of baryons. Using the algebraic approach to hadron structure, we derive closed expressions for both elastic and transition form factors, and consequently for the helicity amplitudes that can be measured in electro- and photoproduction. Effects of spin-flavor symmetry breaking and of swelling of hadrons with increasing excitation energy are considered.
Electromagnetic form factors in a collective model of the nucleon
Energy Technology Data Exchange (ETDEWEB)
Bijker, R.; Iachello, F.; Leviatan, A. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510 (Mexico)]|[Distrito Federale (Mexico)]|[Center for Theoretical Physics, Sloane Laboratory, Yale University, New Haven, Connecticut 06520-8120 (United States)]|[Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel)
1996-10-01
We study the electromagnetic form factors of the nucleon in a collective model of baryons. Using the algebraic approach to hadron structure, we derive closed expressions for both elastic and transition form factors, and consequently for the helicity amplitudes that can be measured in electro- and photoproduction. Effects of spin-flavor symmetry breaking and of swelling of hadrons with increasing excitation energy are considered. {copyright} {ital 1996 The American Physical Society.}
A discrete latent factor model for smoking, cancer and mortality.
Howdon, D.; Jones, A
2013-01-01
This paper investigates the relationships between social circumstances, individual behaviours, and ill-health later in life, with a particular focus on the development of cancer. A discrete latent factor model incorporating individuals' smoking and health outcomes (lifespan and time-to-cancer) is jointly estimated, using the 1984/5 British Health and Lifestyle Survey (HALS) dataset and its July 2009 follow-up, allowing for unobservable factors to affect decisions regarding smoking behaviours ...
Impact of festival factor on electric quantity multiplication forecast model
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
This research aims to improve the forecasting precision of electric quantity. It is discovered that the total electricity consumption considerably increased during the Spring Festival by the analysis of the electric quantity time series from 2002 to 2007 in Shandong province. The festival factor is ascertained to be one of the important seasonal factors affecting the electric quantity fluctuations, and the multiplication model for forecasting is improved by introducing corresponding variables and parameters...
A Bayesian semiparametric factor analysis model for subtype identification.
Sun, Jiehuan; Warren, Joshua L; Zhao, Hongyu
2017-04-25
Disease subtype identification (clustering) is an important problem in biomedical research. Gene expression profiles are commonly utilized to infer disease subtypes, which often lead to biologically meaningful insights into disease. Despite many successes, existing clustering methods may not perform well when genes are highly correlated and many uninformative genes are included for clustering due to the high dimensionality. In this article, we introduce a novel subtype identification method in the Bayesian setting based on gene expression profiles. This method, called BCSub, adopts an innovative semiparametric Bayesian factor analysis model to reduce the dimension of the data to a few factor scores for clustering. Specifically, the factor scores are assumed to follow the Dirichlet process mixture model in order to induce clustering. Through extensive simulation studies, we show that BCSub has improved performance over commonly used clustering methods. When applied to two gene expression datasets, our model is able to identify subtypes that are clinically more relevant than those identified from the existing methods.
Factor selection and structural identification in the interaction ANOVA model.
Post, Justin B; Bondell, Howard D
2013-03-01
When faced with categorical predictors and a continuous response, the objective of an analysis often consists of two tasks: finding which factors are important and determining which levels of the factors differ significantly from one another. Often times, these tasks are done separately using Analysis of Variance (ANOVA) followed by a post hoc hypothesis testing procedure such as Tukey's Honestly Significant Difference test. When interactions between factors are included in the model the collapsing of levels of a factor becomes a more difficult problem. When testing for differences between two levels of a factor, claiming no difference would refer not only to equality of main effects, but also to equality of each interaction involving those levels. This structure between the main effects and interactions in a model is similar to the idea of heredity used in regression models. This article introduces a new method for accomplishing both of the common analysis tasks simultaneously in an interaction model while also adhering to the heredity-type constraint on the model. An appropriate penalization is constructed that encourages levels of factors to collapse and entire factors to be set to zero. It is shown that the procedure has the oracle property implying that asymptotically it performs as well as if the exact structure were known beforehand. We also discuss the application to estimating interactions in the unreplicated case. Simulation studies show the procedure outperforms post hoc hypothesis testing procedures as well as similar methods that do not include a structural constraint. The method is also illustrated using a real data example.
Factor Selection and Structural Identification in the Interaction ANOVA Model
Post, Justin B.; Bondell, Howard D.
2013-01-01
Summary When faced with categorical predictors and a continuous response, the objective of analysis often consists of two tasks: finding which factors are important and determining which levels of the factors differ significantly from one another. Often times these tasks are done separately using Analysis of Variance (ANOVA) followed by a post-hoc hypothesis testing procedure such as Tukey’s Honestly Significant Difference test. When interactions between factors are included in the model the collapsing of levels of a factor becomes a more difficult problem. When testing for differences between two levels of a factor, claiming no difference would refer not only to equality of main effects, but also equality of each interaction involving those levels. This structure between the main effects and interactions in a model is similar to the idea of heredity used in regression models. This paper introduces a new method for accomplishing both of the common analysis tasks simultaneously in an interaction model while also adhering to the heredity-type constraint on the model. An appropriate penalization is constructed that encourages levels of factors to collapse and entire factors to be set to zero. It is shown that the procedure has the oracle property implying that asymptotically it performs as well as if the exact structure were known beforehand. We also discuss the application to estimating interactions in the unreplicated case. Simulation studies show the procedure outperforms post hoc hypothesis testing procedures as well as similar methods that do not include a structural constraint. The method is also illustrated using a real data example. PMID:23323643
Regionalization of climate model results for the North Sea
Energy Technology Data Exchange (ETDEWEB)
Kauker, F. [Alfred-Wegener-Institut fuer Polar- und Meeresforschung, Bremerhaven (Germany); Storch, H. von [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Hydrophysik
2000-07-01
A dynamical downscaling for the North Sea is presented. The numerical model used for the study is the coupled ice-ocean model OPYC. In a hindcast of the years 1979 to 1993 it was forced with atmospheric forcing of the ECMWF reanalysis. The models capability in simulating the observed mean state and variability in the North Sea is demonstrated by the hindcast. Two time scale ranges, from weekly to seasonal and the longer-than-seasonal time scales are investigated. Shorter time scales, for storm surges, are not captured by the model formulation. The main modes of variability of sea level, sea-surface circulation, sea-surface temperature, and sea-surface salinity are described and connections to atmospheric phenomena, like the NAO, are discussed. T106 ''time-slice'' simulations with a ''2 x CO{sub 2}'' horizon are used to estimate the effects of a changing climate on the shelf sea ''North Sea''. The ''2 x CO{sub 2}'' changes in the surface forcing are accompanied by changes in the lateral oceanic boundary conditions taken from a global coupled climate model. For ''2 x CO{sub 2}'' the time mean sea level increases up to 25 cm in the German Bight in the winter, where 15 cm are due to the surface forcing and 10 cm due to thermal expansion. This change is compared to the ''natural'' variability as simulated in the ECMWF integration and found to be not outside the range spanned by it. The variability of sea level on the weekly-to-seasonal time-scales is significantly reduced in the scenario integration. The variability on the longer-than-seasonal time-scales in the control and scenario runs is much smaller then in the ECMWF integration. This is traced back to the use of ''time-slice'' experiments. Discriminating between locally forced changes and changes induced at the lateral oceanic boundaries of the model in the circulation and
Gestational and familial risk factors for childhood astrocytoma: results of a case-control study.
Kuijten, R R; Bunin, G R; Nass, C C; Meadows, A T
1990-05-01
Gestational and familial risk factors were investigated for their association with astrocytoma, the most frequently occurring brain tumor in children. A case-control study of 163 matched pairs was performed. Cases under 15 years of age at diagnosis in 1980-1986 were identified through the tumor registries of 8 hospitals in Pennsylvania, New Jersey, and Delaware. Controls were selected by random digit dialing and were matched to cases for age, race, and telephone area code and exchange. Maternal antinausea medications increased the risk of childhood astrocytoma [OR (odds ratio) = 2.0, P = 0.04]. Cured meat consumption during pregnancy was more common among cases (OR = 1.9, P = 0.07), and a significant trend with increasing frequency of consumption was observed (P = 0.04). Results for gestational exposure to marijuana (OR = 2.8, P = 0.07) were of borderline significance. Gestational exposure to neurally active medications, alcohol, and tobacco were not risk factors. There was a significant trend for cases to be of higher birth weight (P = 0.03). Mental retardation (OR = 3.0, P = 0.04) and cancer (OR = 1.7, P = 0.02) in a relative of the child significantly increased the risk of astrocytoma. Significantly increased risks were observed for brain tumors in relatives of children 0-4 years of age at diagnosis (OR = 6/0, P = 0.04). A significant protective effect was observed for maternal history of miscarriage or stillbirth (OR = 0.5, P = 0.01). The results of this study suggest that some gestational and familial factors may increase the risk of childhood astrocytoma.
Dynamic-structure-factor measurements on a model Lorentz gas
Egelstaff, P. A.; Eder, O. J.; Glaser, W.; Polo, J.; Renker, B.; Soper, A. K.
1990-02-01
A model system for the Lorentz gas can be made [Eder, Chen, and Egelstaff, Proc. Phys. Soc. London 89, 833 (1966); McPherson and Egelstaff, Can. J. Phys. 58, 289 (1980)] by mixing small quantities of hydrogen with an argon host. For neutron-scattering experiments the large H-to-Ar cross section ratio (~200) makes the argon relatively invisible. Dynamic-structure-factor [S(Q,ω) for H2] measurements at room temperature have been made on this system using the IN4 spectrometer at the Institute Laue Langevin, Grenoble, France. Argon densities between 1.9 and 10.5 atoms/nm3 were used for 0.4results are presented to show the qualitative effects observed. The principle observation is a pronounced narrowing of S(Q,ω) as a function of ω as the argon density is increased. This effect is large at low Q and decreases with increasing Q, and also decreases substantially when helium is used in place of argon. In addition, the shape of S(Q,ω) is more complex than can be accommodated within a simple model, but slightly less complicated than a computer simulation so showing the significance of multiple-collision processes.
Validation of the five-factor model of personality across instruments and observers.
McCrae, R R; Costa, P T
1987-01-01
Two data sources--self-reports and peer ratings--and two instruments--adjective factors and questionnaire scales--were used to assess the five-factor model of personality. As in a previous study of self-reports (McCrae & Costa, 1985b), adjective factors of neuroticism, extraversion, openness to experience, agreeableness-antagonism, and conscientiousness-undirectedness were identified in an analysis of 738 peer ratings of 275 adult subjects. Intraclass correlations among raters, ranging from .30 to .65, and correlations between mean peer ratings and self-reports, from .25 to .62, showed substantial cross-observer agreement on all five adjective factors. Similar results were seen in analyses of scales from the NEO Personality Inventory. Items from the adjective factors were used as guides in a discussion of the nature of the five factors. These data reinforce recent appeals for the adoption of the five-factor model in personality research and assessment.
A Dissipative Model for Hydrogen Storage: Existence and Regularity Results
Chiodaroli, Elisabetta
2010-01-01
We prove global existence of a solution to an initial and boundary value problem for a highly nonlinear PDE system. The problem arises from a termomechanical dissipative model describing hydrogen storage by use of metal hydrides. In order to treat the model from an analytical point of view, we formulate it as a phase transition phenomenon thanks to the introduction of a suitable phase variable. Continuum mechanics laws lead to an evolutionary problem involving three state variables: the temperature, the phase parameter and the pressure. The problem thus consists of three coupled partial differential equations combined with initial and boundary conditions. Existence and regularity of the solutions are here investigated by means of a time discretization-a priori estimate-passage to the limit procedure joined with compactness and monotonicity arguments.
Vaccination strategies for SEIR models using feedback linearization. Preliminary results
De la Sen, M; Alonso-Quesada, S
2011-01-01
A linearization-based feedback-control strategy for a SEIR epidemic model is discussed. The vaccination objective is the asymptotically tracking of the removed-by-immunity population to the total population while achieving simultaneously the remaining population (i.e. susceptible plus infected plus infectious) to asymptotically tend to zero. The disease controlpolicy is designed based on a feedback linearization technique which provides a general method to generate families of vaccination policies with sound technical background.
Severe root resorption resulting from orthodontic treatment: Prevalence and risk factors
Directory of Open Access Journals (Sweden)
Caroline Pelagio Raick Maués
2015-02-01
Full Text Available OBJECTIVE: To assess the prevalence of severe external root resorption and its potential risk factors resulting from orthodontic treatment. METHODS: A randomly selected sample was used. It comprised conventional periapical radiographs taken in the same radiology center for maxillary and mandibular incisors before and after active orthodontic treatment of 129 patients, males and females, treated by means of the Standard Edgewise technique. Two examiners measured and defined root resorption according to the index proposed by Levander et al. The degree of external apical root resorption was registered defining resorption in four degrees of severity. To assess intra and inter-rater reproducibility, kappa coefficient was used. Chi-square test was used to assess the relationship between the amount of root resorption and patient's sex, dental arch (maxillary or mandibular, treatment with or without extractions, treatment duration, root apex stage (open or closed, root shape, as well as overjet and overbite at treatment onset. RESULTS: Maxillary central incisors had the highest percentage of severe root resorption, followed by maxillary lateral incisors and mandibular lateral incisors. Out of 959 teeth, 28 (2.9% presented severe root resorption. The following risk factors were observed: anterior maxillary teeth, overjet greater than or equal to 5 mm at treatment onset, treatment with extractions, prolonged therapy, and degree of apex formation at treatment onset. CONCLUSION: This study showed that care must be taken in orthodontic treatment involving extractions, great retraction of maxillary incisors, prolonged therapy, and/or completely formed apex at orthodontic treatment onset.
Severe root resorption resulting from orthodontic treatment: Prevalence and risk factors
Maués, Caroline Pelagio Raick; do Nascimento, Rizomar Ramos; Vilella, Oswaldo de Vasconcellos
2015-01-01
OBJECTIVE: To assess the prevalence of severe external root resorption and its potential risk factors resulting from orthodontic treatment. METHODS: A randomly selected sample was used. It comprised conventional periapical radiographs taken in the same radiology center for maxillary and mandibular incisors before and after active orthodontic treatment of 129 patients, males and females, treated by means of the Standard Edgewise technique. Two examiners measured and defined root resorption according to the index proposed by Levander et al. The degree of external apical root resorption was registered defining resorption in four degrees of severity. To assess intra and inter-rater reproducibility, kappa coefficient was used. Chi-square test was used to assess the relationship between the amount of root resorption and patient's sex, dental arch (maxillary or mandibular), treatment with or without extractions, treatment duration, root apex stage (open or closed), root shape, as well as overjet and overbite at treatment onset. RESULTS: Maxillary central incisors had the highest percentage of severe root resorption, followed by maxillary lateral incisors and mandibular lateral incisors. Out of 959 teeth, 28 (2.9%) presented severe root resorption. The following risk factors were observed: anterior maxillary teeth, overjet greater than or equal to 5 mm at treatment onset, treatment with extractions, prolonged therapy, and degree of apex formation at treatment onset. CONCLUSION: This study showed that care must be taken in orthodontic treatment involving extractions, great retraction of maxillary incisors, prolonged therapy, and/or completely formed apex at orthodontic treatment onset. PMID:25741825
Gutiérrez-Martín, P; Vírseda-Chamorro, M; Salinas Casado, J; Gómez-Rodríguez, A; Esteban-Fuertes, M
2015-05-01
To determine the urodynamic efficacy and factors that influence the urodynamic results of treatment of neurogenic detrusor hyperactivity with intradetrusor injection of botulinum toxin type A (BTX-A) in patients with spinal cord injury (SCI). A retrospective study was conducted with a cohort of 70 patients composed of 40 men and 30 women with stable SCI (mean age, 39 ± 13.3 years) who underwent an intradetrusor injection of 300 IUs of BTX-A. A urodynamic study was conducted prior to the injection and 6 ± 4.3 months after the treatment. New urodynamic studies were subsequently performed up to an interval of 16 ± 12.2 months. The BTX-A significantly increased (p lesion age showed no influence in terms of the increase in bladder capacity. The indwelling urinary catheter (IUC) was the only statistically significant negative factor. The urodynamic effect of BTX-A is maintained for a considerable time interval. The IUC negatively influences the result of the treatment. Copyright © 2014 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.
Analysis of Factors Influencing Measurement Accuracy of Al Alloy Tensile Test Results
Podgornik, Bojan; Žužek, Borut; Sedlaček, Marko; Kevorkijan, Varužan; Hostej, Boris
2016-02-01
In order to properly use materials in design, a complete understanding of and information on their mechanical properties, such as yield and ultimate tensile strength must be obtained. Furthermore, as the design of automotive parts is constantly pushed toward higher limits, excessive measuring uncertainty can lead to unexpected premature failure of the component, thus requiring reliable determination of material properties with low uncertainty. The aim of the present work was to evaluate the effect of different metrology factors, including the number of tested samples, specimens machining and surface quality, specimens input diameter, type of testing and human error on the tensile test results and measurement uncertainty when performed on 2xxx series Al alloy. Results show that the most significant contribution to measurement uncertainty comes from the number of samples tested, which can even exceed 1 %. Furthermore, moving from experimental laboratory conditions to very intense industrial environment further amplifies measurement uncertainty, where even if using automated systems human error cannot be neglected.
Cunha, Carla; Angelucci, Andrea; D'Antoni, Angela; Dobrossy, Mate D; Dunnett, Stephen B; Berardi, Nicoletta; Brambilla, Riccardo
2009-03-01
In this study we analyzed the effect on behavior of a chronic exposure to brain-derived neurotrophic factor (BDNF), by analysing a mouse line overexpressing BDNF under the alphaCaMKII promoter, which drives the transgene expression exclusively to principal neurons of the forebrain. BDNF transgenic mice and their WT littermates were examined with a battery of behavioral tests, in order to evaluate motor coordination, learning, short and long-term memory formation. Our results demonstrate that chronic BDNF overexpression in the central nervous system (CNS) causes learning deficits and short-term memory impairments, both in spatial and instrumental learning tasks. This observation suggests that a widespread increase in BDNF in forebrain networks may result in adverse effects on learning and memory formation.
New JLS-Factor Model versus the Standard JLS Model: A Case Study on Chinese Stock Bubbles
Directory of Open Access Journals (Sweden)
Zongyi Hu
2017-01-01
Full Text Available In this paper, we extend the Johansen-Ledoit-Sornette (JLS model by introducing fundamental economic factors in China (including the interest rate and deposit reserve rate and the historical volatilities of targeted and US equity indices into the original model, which is a flexible tool to detect bubbles and predict regime changes in financial markets. We then derive a general method to incorporate these selected factors in addition to the log-periodic power law signature of herding and compare the prediction accuracy of the critical time between the original and the new JLS models (termed the JLS-factor model by applying these two models to fit two well-known Chinese stock indices in three bubble periods. The results show that the JLS-factor model with Chinese characteristics successfully depicts the evolutions of bubbles and “antibubbles” and constructs efficient end-of-bubble signals for all bubbles in Chinese stock markets. In addition, the results of standard statistical tests demonstrate the excellent explanatory power of these additive factors and confirm that the new JLS model provides useful improvements over the standard JLS model.
Blade element momentum modeling of inflow with shear in comparison with advanced model results
DEFF Research Database (Denmark)
Aagaard Madsen, Helge; Riziotis, V.; Zahle, Frederik
2012-01-01
There seems to be a significant uncertainty in aerodynamic and aeroelastic simulations on megawatt turbines operating in inflow with considerable shear, in particular with the engineering blade element momentum (BEM) model, commonly implemented in the aeroelastic design codes used by industry....... Computations with advanced vortex and computational fluid dynamics models are used to provide improved insight into the complex flow phenomena and rotor aerodynamics caused by the sheared inflow. One consistent result from the advanced models is the variation of induced velocity as a function of azimuth when...... a higher power than in uniform flow. On the basis of the consistent azimuthal induction variations seen in the advanced model results, three different BEM implementation methods are discussed and tested in the same aeroelastic code. A full local BEM implementation on an elemental stream tube in both...
Modeling Image Structure with Factorized Phase-Coupled Boltzmann Machines
Cadieu, Charles F
2010-01-01
We describe a model for capturing the statistical structure of local amplitude and local spatial phase in natural images. The model is based on a recently developed, factorized third-order Boltzmann machine that was shown to be effective at capturing higher-order structure in images by modeling dependencies among squared filter outputs (Ranzato and Hinton, 2010). Here, we extend this model to $L_p$-spherically symmetric subspaces. In order to model local amplitude and phase structure in images, we focus on the case of two dimensional subspaces, and the $L_2$-norm. When trained on natural images the model learns subspaces resembling quadrature-pair Gabor filters. We then introduce an additional set of hidden units that model the dependencies among subspace phases. These hidden units form a combinatorial mixture of phase coupling distributions, concentrated in the sum and difference of phase pairs. When adapted to natural images, these distributions capture local spatial phase structure in natural images.
The physical model of a terraced plot: first results
Perlotto, Chiara; D'Agostino, Vincenzo; Buzzanca, Giacomo
2017-04-01
Terrace building have been expanded in the 19th century because of the increased demographic pressure and the need to crop additional areas at steeper slopes. Terraces are also important to regulate the hydrological behavior of the hillslope. Few studies are available in literature on rainfall-runoff processes and flood risk mitigation in terraced areas. Bench terraces, reducing the terrain slope and the length of the overland flow, quantitatively control the runoff flow velocity, facilitating the drainage and thus leading to a reduction of soil erosion. The study of the hydrologic-hydraulic function of terraced slopes is essential in order to evaluate their possible use to cooperate for flood-risk mitigation also preserving the landscape value. This research aims to better focus the times of the hydrological response, which are determined by a hillslope plot bounded by a dry-stone wall, considering both the overland flow and the groundwater. A physical model, characterized by a quasi-real scale, has been built to reproduce the behavior of a 3% outward sloped terrace at bare soil condition. The model consists of a steel metal box (1 m large, 3.3 m long, 2 m high) containing the hillslope terrain. The terrain is equipped with two piezometers, 9 TDR sensors measuring the volumetric water content, a surface spillway at the head releasing the steady discharge under test, a scale at the wall base to measure the outflowing discharge. The experiments deal with different initial moisture condition (non-saturated and saturated), and discharges of 19.5, 12.0 and 5.0 l/min. Each experiment has been replicated, conducting a total number of 12 tests. The volumetric water content analysis produced by the 9 TDR sensors was able to provide a quite satisfactory representation of the soil moisture during the runs. Then, different lag times at the outlet since the inflow initiation were measured both for runoff and groundwater. Moreover, the time of depletion and the piezometer
Five-factor model personality traits in opioid dependence
Directory of Open Access Journals (Sweden)
Nordvik Hilmar
2007-08-01
Full Text Available Abstract Background Personality traits may form a part of the aetiology of opioid dependence. For instance, opioid dependence may result from self-medication in emotionally unstable individuals, or from experimenting with drugs in sensation seekers. The five factor model (FFM has obtained a central position in contemporary personality trait theory. The five factors are: Neuroticism, Extraversion, Openness to Experience, Agreeableness and Conscientiousness. Few studies have examined whether there is a distinct personality pattern associated with opioid dependence. Methods We compared FFM personality traits in 65 opioid dependent persons (mean age 27 years, 34% females in outpatient counselling after a minimum of 5 weeks in buprenorphine replacement therapy, with those in a non-clinical, age- and sex-matched sample selected from a national database. Personality traits were assessed by a Norwegian version of the Revised NEO Personality Inventory (NEO PI-R, a 240-item self-report questionnaire. Cohen's d effect sizes were calculated for the differences in personality trait scores. Results The opioid-dependent sample scored higher on Neuroticism, lower on Extraversion and lower on Conscientiousness (d = -1.7, 1.2 and 1.7, respectively than the controls. Effects sizes were small for the difference between the groups in Openness to experience scores and Agreeableness scores. Conclusion We found differences of medium and large effect sizes between the opioid dependent group and the matched comparison group, suggesting that the personality traits of people with opioid dependence are in fact different from those of non-clinical peers.
Institute of Scientific and Technical Information of China (English)
Guan Weibing; Wong Lai-Ah; Xu Dongfeng
2001-01-01
In the present study, the ecosystem-based water quality model was applied to the Pearl River (Zhujiang) Estuary. The model results successfully represent the distribution trend of nutrients and dissolved oxygen both in the horizontal and vertical planes during the flood season, and it shows that the model has taken into consideration the key part of the dynamical, chemical and biological processes existing in the Zhujiang Estuary. The further studies illustrate that nitrogen is in plenty while phosphorus and light limit the phytoplankton biomass in the Zhujiang Estuary during the flood season.
Golay, Philippe; Reverte, Isabelle; Rossier, Jérôme; Favez, Nicolas; Lecerf, Thierry
2013-06-01
The interpretation of the Wechsler Intelligence Scale for Children--Fourth Edition (WISC-IV) is based on a 4-factor model, which is only partially compatible with the mainstream Cattell-Horn-Carroll (CHC) model of intelligence measurement. The structure of cognitive batteries is frequently analyzed via exploratory factor analysis and/or confirmatory factor analysis. With classical confirmatory factor analysis, almost all cross-loadings between latent variables and measures are fixed to zero in order to allow the model to be identified. However, inappropriate zero cross-loadings can contribute to poor model fit, distorted factors, and biased factor correlations; most important, they do not necessarily faithfully reflect theory. To deal with these methodological and theoretical limitations, we used a new statistical approach, Bayesian structural equation modeling (BSEM), among a sample of 249 French-speaking Swiss children (8-12 years). With BSEM, zero-fixed cross-loadings between latent variables and measures are replaced by approximate zeros, based on informative, small-variance priors. Results indicated that a direct hierarchical CHC-based model with 5 factors plus a general intelligence factor better represented the structure of the WISC-IV than did the 4-factor structure and the higher order models. Because a direct hierarchical CHC model was more adequate, it was concluded that the general factor should be considered as a breadth rather than a superordinate factor. Because it was possible for us to estimate the influence of each of the latent variables on the 15 subtest scores, BSEM allowed improvement of the understanding of the structure of intelligence tests and the clinical interpretation of the subtest scores. PsycINFO Database Record (c) 2013 APA, all rights reserved.
The effects of motivational factors on car use: a multidisciplinary modelling approach
Energy Technology Data Exchange (ETDEWEB)
Steg, L.; Ras, M. [University of Groningen (Netherlands). Centre for Environmental and Traffic Psychology; Geurs, K. [National Institute of Public Health and Environment, Bilthoven (Netherlands)
2001-11-01
Current transport models usually do not take motivational factors into account, and if they do, it is only implicitly. This paper presents a modelling approach aimed at explicitly examining the effects of motivational factors on present and future car use in the Netherlands. A car-use forecasting model for the years 2010 and 2020 was constructed on the basis of (i) a multinominal regression analysis, which revealed the importance of a motivational variable (viz., problem awareness) in explaining current car-use behavior separate from socio-demographic and socio-economic variables, and (ii) a population model constructed to forecast the size and composition of the Dutch population. The results show that car use could be better explained by taking motivational factors explicitly into account, and that the level of car use forecast might change significantly if changes in motivations are assumed. The question on how motivational factors could be incorporated into current (Dutch) national transport models was also addressed. (author)
Exact results in modeling planetary atmospheres-III
Energy Technology Data Exchange (ETDEWEB)
Pelkowski, J. [Institut fuer Atmosphaere und Umwelt, J.W. Goethe Universitaet Frankfurt, Campus Riedberg, Altenhoferallee 1, D-60438 Frankfurt a.M. (Germany)], E-mail: Pelkowski@meteor.uni-frankfurt.de; Chevallier, L. [Observatoire de Paris-Meudon, Laboratoire LUTH, 5 Place Jules Janssen, 92195 Meudon cedex (France); Rutily, B. [Universite de Lyon, F-69003 Lyon (France); Universite Lyon 1, Observatoire de Lyon, 9 avenue Charles Andre, F-69230 Saint-Genis-Laval (France); CNRS, UMR 5574, Centre de Recherche Astrophysique de Lyon (France); Ecole Normale Superieure de Lyon, F-69007 Lyon (France); Titaud, O. [Centro de Modelamiento Matematico, UMI 2807 CNRS-UChile, Blanco Encalada 2120 - 7 Piso, Casilla 170 - Correo 3, Santiago (Chile)
2008-01-15
We apply the semi-gray model of our previous paper to the particular case of the Earth's atmosphere, in order to illustrate quantitatively the inverse problem associated with the direct problem we dealt with before. From given climatological values of the atmosphere's spherical albedo and transmittance for visible radiation, the single-scattering albedo and the optical thickness in the visible are inferred, while the infrared optical thickness is deduced for given global average surface temperature. Eventually, temperature distributions in terms of the infrared optical depth will be shown for a terrestrial atmosphere assumed to be semi-gray and, locally, in radiative and thermodynamic equilibrium.
Exact results in modeling planetary atmospheres-I. Gray atmospheres
Energy Technology Data Exchange (ETDEWEB)
Chevallier, L. [Observatoire de Paris-Meudon, Laboratoire LUTH, 5 Place Jules Janssen, 92195 Meudon cedex (France)]. E-mail: loic.chevallier@obspm.fr; Pelkowski, J. [Institut fuer Meteorologie und Geophysik, J.W. Goethe Universitaet Frankfurt, Robert Mayer Strasse 1, D-60325 Frankfurt (Germany); Rutily, B. [Universite de Lyon, Lyon, F-69000 (France) and Universite Lyon 1, Villeurbanne, F-69622 (France) and Centre de Recherche Astronomique de Lyon, Observatoire de Lyon, 9 avenue Charles Andre, Saint-Genis Laval cedex, F-69561 (France) and CNRS, UMR 5574; Ecole Normale Superieure de Lyon, Lyon (France)
2007-04-15
An exact model is proposed for a gray, isotropically scattering planetary atmosphere in radiative equilibrium. The slab is illuminated on one side by a collimated beam and is bounded on the other side by an emitting and partially reflecting ground. We provide expressions for the incident and reflected fluxes on both boundary surfaces, as well as the temperature of the ground and the temperature distribution in the atmosphere, assuming the latter to be in local thermodynamic equilibrium. Tables and curves of the temperature distribution are included for various values of the optical thickness. Finally, semi-infinite atmospheres illuminated from the outside or by sources at infinity is dealt with.
Directory of Open Access Journals (Sweden)
Christian eGeiser
2015-08-01
Full Text Available Models of confirmatory factor analysis (CFA are frequently applied to examine the convergent validity of scores obtained from multiple raters or methods in so-called multitrait-multimethod (MTMM investigations. Many applications of CFA-MTMM and similarly structured models result in solutions in which at least one method (or specific factor shows non-significant loading or variance estimates. Eid et al. (2008 distinguished between MTMM measurement designs with interchangeable (randomly selected versus structurally different (fixed methods and showed that each type of measurement design implies specific CFA-MTMM measurement models. In the current study, we hypothesized that some of the problems that are commonly seen in applications of CFA-MTMM models may be due to a mismatch between the underlying measurement design and fitted models. Using simulations, we found that models with M method factors (where M is the total number of methods and unconstrained loadings led to a higher proportion of solutions in which at least one method factor became empirically unstable when these models were fit to data generated from structurally different methods. The simulations also revealed that commonly used model goodness-of-fit criteria frequently failed to identify incorrectly specified CFA-MTMM models. We discuss implications of these findings for other complex CFA models in which similar issues occur, including nested (bifactor and latent state-trait models.
Geiser, Christian; Bishop, Jacob; Lockhart, Ginger
2015-01-01
Models of confirmatory factor analysis (CFA) are frequently applied to examine the convergent validity of scores obtained from multiple raters or methods in so-called multitrait-multimethod (MTMM) investigations. Many applications of CFA-MTMM and similarly structured models result in solutions in which at least one method (or specific) factor shows non-significant loading or variance estimates. Eid et al. (2008) distinguished between MTMM measurement designs with interchangeable (randomly selected) vs. structurally different (fixed) methods and showed that each type of measurement design implies specific CFA-MTMM measurement models. In the current study, we hypothesized that some of the problems that are commonly seen in applications of CFA-MTMM models may be due to a mismatch between the underlying measurement design and fitted models. Using simulations, we found that models with M method factors (where M is the total number of methods) and unconstrained loadings led to a higher proportion of solutions in which at least one method factor became empirically unstable when these models were fit to data generated from structurally different methods. The simulations also revealed that commonly used model goodness-of-fit criteria frequently failed to identify incorrectly specified CFA-MTMM models. We discuss implications of these findings for other complex CFA models in which similar issues occur, including nested (bifactor) and latent state-trait models. PMID:26283977
The structure of musical preferences: a five-factor model.
Rentfrow, Peter J; Goldberg, Lewis R; Levitin, Daniel J
2011-06-01
Music is a cross-cultural universal, a ubiquitous activity found in every known human culture. Individuals demonstrate manifestly different preferences in music, and yet relatively little is known about the underlying structure of those preferences. Here, we introduce a model of musical preferences based on listeners' affective reactions to excerpts of music from a wide variety of musical genres. The findings from 3 independent studies converged to suggest that there exists a latent 5-factor structure underlying music preferences that is genre free and reflects primarily emotional/affective responses to music. We have interpreted and labeled these factors as (a) a Mellow factor comprising smooth and relaxing styles; (b) an Unpretentious factor comprising a variety of different styles of sincere and rootsy music such as is often found in country and singer-songwriter genres; (c) a Sophisticated factor that includes classical, operatic, world, and jazz; (d) an Intense factor defined by loud, forceful, and energetic music; and (e) a Contemporary factor defined largely by rhythmic and percussive music, such as is found in rap, funk, and acid jazz. The findings from a fourth study suggest that preferences for the MUSIC factors are affected by both the social and the auditory characteristics of the music.
Testing the AGN unification model in the infrared. First results with GTC/CanariCam
Ramos Almeida, C.
2015-05-01
The unified model for Active Galactic Nuclei (AGN) accounts for a variety of observational differences in terms of viewing geometry alone. However, from the fitting of high spatial resolution infrared (IR) data with clumpy torus models, it has been hinted that the immediate dusty surroundings of Type-1 and 2 Seyfert nuclei might be intrinsically different in terms of covering factor (torus width and number of clouds). Moreover, these torus covering factors also showed variations among objects belonging to the same type, in contradiction with simple unification. Interestingly, these intrinsic differences in Seyfert tori could explain, for example, the lack of broad optical lines in the polarized spectra of about half of the brightest Seyfert 2 galaxies. On the other hand, recent IR interferometry studies have revealed that, in at least four Seyfert galaxies, the mid-IR emission is elongated in the polar direction. These results are difficult to reconcile with unified models, which claim that the bulk of the mid-IR emission comes from the torus. In this invited contribution I summarize the latest results on high angular resolution IR studies of AGN, which constitute a crucial test for AGN unification. These results include those from the mid-infrared instrument CanariCam on the 10.4 m Gran Telescopio CANARIAS (GTC), which are starting to be published by the CanariCam AGN team, Los Piratas (https://sites.google.com/site/piratasrelatedpublications).
Modeling wind adjustment factor and midflame wind speed for Rothermel's surface fire spread model
Patricia L. Andrews
2012-01-01
Rothermel's surface fire spread model was developed to use a value for the wind speed that affects surface fire, called midflame wind speed. Models have been developed to adjust 20-ft wind speed to midflame wind speed for sheltered and unsheltered surface fuel. In this report, Wind Adjustment Factor (WAF) model equations are given, and the BehavePlus fire modeling...
Enhancement Factors in Ozone Absorption Based on the Surface Renewal Model and its Application
Institute of Scientific and Technical Information of China (English)
程江; 杨卓如; 陈焕钦; C.H.Kuo; M.E.Zappi
2000-01-01
Based on the Danckwerts surface renewal model, a simple explicit expression of the enhancement factor in ozone absorption with a first order ozone self-decomposition and parallel second order ozonation reactions has been derived. The results are compared with our previous work based on the film theory. The 2,4-dichlorophenol destruction rate by ozonation is predicted using the enhancement factor model in this paper.
Large Deviation Results for Generalized Compound Negative Binomial Risk Models
Institute of Scientific and Technical Information of China (English)
Fan-chao Kong; Chen Shen
2009-01-01
In this paper we extend and improve some results of the large deviation for random sums of random variables.Let {Xn;n≥1} be a sequence of non-negative,independent and identically distributed random variables with common heavy-tailed distribution function F and finite mean μ∈R+,{N(n);n≥0} be a sequence of negative binomial distributed random variables with a parameter p ∈(0,1),n≥0,let {M(n);n≥0} be a Poisson process with intensity λ0.Suppose {N(n);n≥0},{Xn;n≥1} and {M(n);n≥0} are mutually results.These results can be applied to certain problems in insurance and finance.
Some results on 4~m2~n designs with clear two-factor interaction components
Institute of Scientific and Technical Information of China (English)
2008-01-01
Clear effects criterion is one of the important rules for selecting optimal fractional factorial designs,and it has become an active research issue in recent years.Tang et al.derived upper and lower bounds on the maximum number of clear two-factor interactions(2fi’s) in 2n-(n-k) fractional factorial designs of resolutions III and IV by constructing a 2n-(n-k) design for given k,which are only restricted for the symmetrical case.This paper proposes and studies the clear effects problem for the asymmetrical case.It improves the construction method of Tang et al.for 2n-(n-k) designs with resolution III and derives the upper and lower bounds on the maximum number of clear two-factor interaction components(2fic’s) in 4m2n designs with resolutions III and IV.The lower bounds are achieved by constructing specific designs.Comparisons show that the number of clear 2fic’s in the resulting design attains its maximum number in many cases,which reveals that the construction methods are satisfactory when they are used to construct 4m2n designs under the clear effects criterion.
Some results on 4m2n designs with clear two-factor interaction components
Institute of Scientific and Technical Information of China (English)
ZHAO ShengLi; ZHANG RunChu; LIU MinQian
2008-01-01
Clear effects criterion is one of the important rules for selecting optimal fractional factorial designs, and it has become an active research issue in recent years.Tang et al. derived upper and lower bounds on the maximum number of clear two-factor interactions (2fi's) in 2n-(n-k)fractional factorial designs of resolutions Ⅲ and Ⅳ by constructing a 2n-(n-k) design for given k, which are only restricted for the symmetrical case. This paper proposes and studies the clear effects problem for the asymmetrical case. It improves the construction method of Tang et al. for 2n-(n-k)designs with resolution Ⅲ and derives the upper and lower bounds on the maximum number of clear two-factor interaction components(2fic's) in 4m2n designs with resolutions Ⅲ and Ⅳ. The lower bounds are achieved by constructing specific designs. Comparisons show that the number of clear 2fic's in the resulting design attains its maximum number in many cases, which reveals that the construction methods are satisfactory when they are used to construct 4m2n designs under the clear effects criterion.
Fleury, Agnès; Escobar, Alfonso; Fragoso, Gladis; Sciutto, Edda; Larralde, Carlos
2010-04-01
Human neurocysticercosis (NC) is endemic in most countries of Latin America, Asia and Africa and is re-emerging in some industrialized nations. Both within and among endemic countries, NC is very variable in its clinical and radiological features, as well as in the intensity of the immuno-inflammatory reactions of the hosts. This review, focusing on the Mexican experience, describes and interprets the heterogeneity of NC as the result of different combinations among factors associated with the parasite, host and environment. The review may serve to foster similar descriptive efforts in other endemic areas of the world in order to facilitate the identification of the distinct factors that participate in the complex pathogenesis and diverse clinical outcomes of NC. In particular, it is necessary to understand the precise physiopathology of the inflammatory reaction associated with NC, as inflammation is one of the characteristics of those NC cases that are clinically more severe and less responsive to current treatments. Devising new medical interventions through the use of molecular regulators of the innate and adaptive immune responses of the host is a largely unexplored approach that could improve the existing forms of treatment. Copyright 2010 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.
Theoretical Modeling of ISO Results on Planetary Nebula NGC 7027
Yan, M.; Federman, S. R.; Dalgarno, A.; Bjorkman, J. E.
1999-04-01
We present a thermal and chemical model of the neutral envelope of planetary nebula NGC 7027. In our model, the neutral envelope is composed of a thin dense shell of constant density and an outer stellar wind region with the usual inverse-square law density profile. The thermal and chemical structure is calculated with the assumption that the incident radiation field on the inner surface equals 0.5×105 times Draine's fit to the average interstellar far-ultraviolet field. The rate coefficient for H2 formation on grains is assumed to be 1/5 the usual value to take into account the lower dust-gas mass ratio in the neutral envelope of NGC 7027. The calculated temperature in the dense shell decreases from 3000 to under 200 K. Once the temperature drops to 200 K, we assume that it remains at 200 K until the outer edge of the dense shell is reached, so that the observed intensities of CO J=16-15, 15-14, and 14-13 lines can be reproduced. The 200 K temperature can be interpreted as the average temperature of the shocked gas just behind the forward shock front in the framework of the interacting stellar wind theory. We calculate the intensities of the molecular far-infrared rotational lines by using a revised version of the escape probability formalism. The theoretical intensities for rotational lines of CO (from J=29-28 to J=14-13), CH+, OH, and CH are shown to be in good agreement with ISO observations. The H2 rovibrational line intensities are also calculated and are in agreement with available observations.
Combining forming results via weld models to powerful numerical assemblies
Kose, K.; Rietman, Bert
2004-01-01
Forming simulations generally give satisfying results with respect to thinning, stresses, changed material properties and, with a proper springback calculation, the geometric form. The joining of parts by means of welding yields an extra change of the material properties and the residual stresses.
Combining forming results via weld models to powerful numerical assemblies
Kose, K.; Rietman, B.
2004-01-01
Forming simulations generally give satisfying results with respect to thinning, stresses, changed material properties and, with a proper springback calculation, the geometric form. The joining of parts by means of welding yields an extra change of the material properties and the residual stresses. W
Brinton, Louise A.
2014-01-01
Background The etiology of male breast cancer is poorly understood, partly because of its relative rarity. Although genetic factors are involved, less is known regarding the role of anthropometric and hormonally related risk factors. Methods In the Male Breast Cancer Pooling Project, a consortium of 11 case–control and 10 cohort investigations involving 2405 case patients (n = 1190 from case–control and n = 1215 from cohort studies) and 52013 control subjects, individual participant data were harmonized and pooled. Unconditional logistic regression generated study design–specific (case–control/cohort) odds ratios (ORs) and 95% confidence intervals (CIs), with exposure estimates combined using fixed effects meta-analysis. All statistical tests were two-sided. Results Risk was statistically significantly associated with weight (highest/lowest tertile: OR = 1.36; 95% CI = 1.18 to 1.57), height (OR = 1.18; 95% CI = 1.01 to 1.38), and body mass index (BMI; OR = 1.30; 95% CI = 1.12 to 1.51), with evidence that recent rather than distant BMI was the strongest predictor. Klinefelter syndrome (OR = 24.7; 95% CI = 8.94 to 68.4) and gynecomastia (OR = 9.78; 95% CI = 7.52 to 12.7) were also statistically significantly associated with risk, relations that were independent of BMI. Diabetes also emerged as an independent risk factor (OR = 1.19; 95% CI = 1.04 to 1.37). There were also suggestive relations with cryptorchidism (OR = 2.18; 95% CI = 0.96 to 4.94) and orchitis (OR = 1.43; 95% CI = 1.02 to 1.99). Although age at onset of puberty and histories of infertility were unrelated to risk, never having had children was statistically significantly related (OR = 1.29; 95% CI = 1.01 to 1.66). Among individuals diagnosed at older ages, a history of fractures was statistically significantly related (OR = 1.41; 95% CI = 1.07 to 1.86). Conclusions Consistent findings across case–control and cohort investigations, complemented by pooled analyses, indicated important roles for
Investigations about Starting Cracks in DC-Casting of 6063-Type Billets Part II: Modelling Results
Jensen, E. K.; Schneider, W.
Influence on starting crack tendency of varying a number of casting parameters has been studied by experiments, Part I (1), and by model calculations, Part II. Both studies point to starting block shape as a most important single factor in controlling starting cracks. By using the thermal model ALSIM-2 in analysing initial experimental results, the variable heat transfer towards the starting block was determined. This made possible a satisfactory model analysis of the starting phase and likewise the formulation of a useful cracking concept. Thus by using calculated and measured liquid pool depth curve in the starting phase of casting as a basis, an effective starting block shape was found. This new shape practically eliminates the starting crack problems in extrusion billets of the AA6063 type alloys.
DEFF Research Database (Denmark)
Balling, N.; Poulsen, Søren Erbs; Bording, Thue Sylvester
2015-01-01
equilibrium temperature logging has been carried out in a number of accessible deep boreholes. A regional distribution of subsurface temperatures is obtained by combining measurements and 3D numerical modelling in which the heat equation is solved. Modelling results are constrained by observations in terms....... Information of subsurface temperature distribution originates from direct measurements in boreholes and from indirect theoretical modelling. "Point observations" of varying quality are available as industrially measured "Bottom Hole Temperatures" from deep exploration boreholes and accurate continuous...... of available measured temperatures and observed surface heat flow. Information on subsurface thermal conductivity, which is a critical parameter, is obtained from core measurements and well-log analyses. Interval temperature gradients are found to vary by a factor of three to four across lithologies...
Linear Factor Models and the Estimation of Expected Returns
Sarisoy, Cisil; de Goeij, Peter; Werker, Bas
2015-01-01
Estimating expected returns on individual assets or portfolios is one of the most fundamental problems of finance research. The standard approach, using historical averages,produces noisy estimates. Linear factor models of asset pricing imply a linear relationship between expected returns and exposu
Linear Factor Models and the Estimation of Expected Returns
Sarisoy, Cisil; de Goeij, Peter; Werker, Bas
2016-01-01
Linear factor models of asset pricing imply a linear relationship between expected returns of assets and exposures to one or more sources of risk. We show that exploiting this linear relationship leads to statistical gains of up to 31% in variances when estimating expected returns on individual asse
Reproductive Behavior and Personality Traits of the Five Factor Model
Jokela, Markus; Alvergne, Alexandra; Pollet, Thomas V.; Lummaa, Virpi
2011-01-01
We examined associations between Five Factor Model personality traits and various outcomes of reproductive behavior in a sample of 15 729 women and men from the Wisconsin Longitudinal Study (WLS) and Midlife Development in the United States (MIDUS) survey. Personality and reproductive history was se
Tests of risk premia in linear factor models
Kleibergen, F.
2009-01-01
We show that statistical inference on the risk premia in linear factor models that is based on the Fama-MacBeth (FM) and generalized least squares (GLS) two-pass risk premia estimators is misleading when the β’s are small and/or the number of assets is large. We propose novel statistics, that are ba
Tests of risk premia in linear factor models
Kleibergen, F.R.
2005-01-01
We show that inference on risk premia in linear factor models that is based on the Fama-MacBeth and GLS risk premia estimators is misleading when the ß’s are small and/or the number of assets is large. We propose some novel statistics that remain trustworthy in these cases. The inadequacy of Fama-Ma
Tests of risk premia in linear factor models
Kleibergen, F.
2009-01-01
We show that statistical inference on the risk premia in linear factor models that is based on the Fama-MacBeth (FM) and generalized least squares (GLS) two-pass risk premia estimators is misleading when the β’s are small and/or the number of assets is large. We propose novel statistics, that are
Risk factors and prognostic models for perinatal asphyxia at term
Ensing, S.
2015-01-01
This thesis will focus on the risk factors and prognostic models for adverse perinatal outcome at term, with a special focus on perinatal asphyxia and obstetric interventions during labor to reduce adverse pregnancy outcomes. For the majority of the studies in this thesis we were allowed to use data
Bayesian Estimation of Random Coefficient Dynamic Factor Models
Song, Hairong; Ferrer, Emilio
2012-01-01
Dynamic factor models (DFMs) have typically been applied to multivariate time series data collected from a single unit of study, such as a single individual or dyad. The goal of DFMs application is to capture dynamics of multivariate systems. When multiple units are available, however, DFMs are not suited to capture variations in dynamics across…
Bayesian Gaussian Copula Factor Models for Mixed Data.
Murray, Jared S; Dunson, David B; Carin, Lawrence; Lucas, Joseph E
2013-06-01
Gaussian factor models have proven widely useful for parsimoniously characterizing dependence in multivariate data. There is a rich literature on their extension to mixed categorical and continuous variables, using latent Gaussian variables or through generalized latent trait models acommodating measurements in the exponential family. However, when generalizing to non-Gaussian measured variables the latent variables typically influence both the dependence structure and the form of the marginal distributions, complicating interpretation and introducing artifacts. To address this problem we propose a novel class of Bayesian Gaussian copula factor models which decouple the latent factors from the marginal distributions. A semiparametric specification for the marginals based on the extended rank likelihood yields straightforward implementation and substantial computational gains. We provide new theoretical and empirical justifications for using this likelihood in Bayesian inference. We propose new default priors for the factor loadings and develop efficient parameter-expanded Gibbs sampling for posterior computation. The methods are evaluated through simulations and applied to a dataset in political science. The models in this paper are implemented in the R package bfa.
Validation of a Four-Factor Model of Career Indecision
Brown, Steven D.; Hacker, Jason; Abrams, Matthew; Carr, Andrea; Rector, Christopher; Lamp, Kristen; Telander, Kyle; Siena, Anne
2012-01-01
Two studies were designed to explore whether a meta-analytically derived four-factor model of career indecision (Brown & Rector, 2008) could be replicated at the primary and secondary data levels. In the first study, an initial pool of 167 items was written based on 35 different instruments whose scores had loaded saliently on at least one…
Validation of a Four-Factor Model of Career Indecision
Brown, Steven D.; Hacker, Jason; Abrams, Matthew; Carr, Andrea; Rector, Christopher; Lamp, Kristen; Telander, Kyle; Siena, Anne
2012-01-01
Two studies were designed to explore whether a meta-analytically derived four-factor model of career indecision (Brown & Rector, 2008) could be replicated at the primary and secondary data levels. In the first study, an initial pool of 167 items was written based on 35 different instruments whose scores had loaded saliently on at least one…
A novel latent factor model for recommender system
National Research Council Canada - National Science Library
Kumar, Bipul
2016-01-01
... a latent factor model that caters to both accuracy and efficiency by reducing the number of latent features of either users or items making it less complex than Funk-SVD, where latent features of both users and items are equal and often larger. A comprehensive empirical evaluation of accuracy on two publicly available, amazon and ml-100 k datasets rev...
Factorization model for distributions of quarks in hadrons
Energy Technology Data Exchange (ETDEWEB)
Ermolaev, B.I. [Ioffe Physico-Technical Institute, St. Petersburg (Russian Federation); Greco, M. [University Roma Tre, Department of Mathematics and Physics, Rome (Italy); INFN, Rome (Italy); Troyan, S.I. [St. Petersburg Institute of Nuclear Physics, Gatchina (Russian Federation)
2015-07-15
We consider distributions of unpolarized (polarized) quarks in unpolarized (polarized) hadrons. Our approach is based on QCD factorization. We begin with a study of the basic factorization for the parton-hadron scattering amplitudes in the forward kinematics and suggest a model for non-perturbative contributions to such amplitudes. This model is based on this simple observation: after emitting an active quark by the initial hadron, the remaining set of quarks and gluons becomes unstable, so a description of this colored state can approximately be done in terms of resonances, which leads to expressions of the Breit-Wigner type. Then we reduce these formulas to obtain explicit expressions for the quark-hadron scattering amplitudes and quark distributions in K{sub T}- and collinear factorizations. (orig.)
Factorization model for distributions of quarks in hadrons
Ermolaev, B I; Troyan, S I
2015-01-01
We consider distributions of unpolarized (polarized) quarks in unpolarized (polarized) hadrons. Our approach is based on QCD factorization. We begin with study of Basic factorization for the parton-hadron scattering amplitudes in the forward kinematics and suggest a model for non-perturbative contributions to such amplitudes. This model is based on the simple observation: after emitting an active quark by the initial hadron, the remaining set quarks and gluons becomes unstable, so description of this colored state can approximately be done in terms of resonances, which leads to expressions of the Breit-Wigner type. for non-perturbative contributions to the distributions of unpolarized and polarized quarks in the hadrons. Then we reduce these formulae to obtain explicit expressions for the quark-hadron scattering amplitudes and quark distributions in K_T- and Collinear factorizations.
Prevalence and Factors Associated with Teen Pregnancy in Vietnam: Results from Two National Surveys
Directory of Open Access Journals (Sweden)
Huong Nguyen
2016-05-01
Full Text Available This study asked two broad questions: (1 what is the prevalence of teen pregnancy in contemporary Vietnam; and (2 what selected social, family, and individual factors are associated with teen pregnancy in Vietnam? The study utilized Vietnam Survey Assessment of Vietnamese Youth surveys conducted in 2003 and 2008 to answer the two research questions within the context of fast political, economic, and social change in Vietnam in the last two decades. Results of this study show that the prevalence of pregnancy among Vietnamese teenagers in the surveys was stable at 4%, or 40 pregnancies per 1000 adolescent girls aged 14 to 19. Age, experience of domestic violence, and early sexual debut were positively correlated with higher odds of teenage pregnancy for both survey cohorts; however, being an ethnic minority, educational attainment, sexual education at school, Internet use, and depressive symptoms were significantly related to teenage pregnancy only in the 2008 cohort.
Park, Elisa L.
2009-01-01
The purpose of this study is to understand the dynamics of Korean students' international mobility to study abroad by using the 2-D Model. The first D, "the driving force factor," explains how and what components of the dissatisfaction with domestic higher education perceived by Korean students drives students' outward mobility to seek…
Directory of Open Access Journals (Sweden)
J. G. Hemann
2009-01-01
Full Text Available A Positive Matrix Factorization receptor model for aerosol pollution source apportionment was fit to a synthetic dataset simulating one year of daily measurements of ambient PM_{2.5} concentrations, comprised of 39 chemical species from nine pollutant sources. A novel method was developed to estimate model fit uncertainty and bias at the daily time scale, as related to factor contributions. A circular block bootstrap is used to create replicate datasets, with the same receptor model then fit to the data. Neural networks are trained to classify factors based upon chemical profiles, as opposed to correlating contribution time series, and this classification is used to align factor orderings across the model results associated with the replicate datasets. Factor contribution uncertainty is assessed from the distribution of results associated with each factor. Comparing modeled factors with input factors used to create the synthetic data assesses bias. The results indicate that variability in factor contribution estimates does not necessarily encompass model error: contribution estimates can have small associated variability across results yet also be very biased. These findings are likely dependent on characteristics of the data.
Cognition and the five-factor model of the positive and negative syndrome scale in schizophrenia.
Rodriguez-Jimenez, Roberto; Bagney, Alexandra; Mezquita, Laura; Martinez-Gras, Isabel; Sanchez-Morla, Eva-Maria; Mesa, Natalia; Ibañez, Manuel-Ignacio; Diez-Martin, Justo; Jimenez-Arriero, Miguel-Angel; Lobo, Antonio; Santos, Jose-Luis; Palomo, Tomas
2013-01-01
Different exploratory and confirmatory factorial analyses of the Positive and Negative Syndrome Scale (PANSS) have found a number of factors other than the original positive, negative, and general psychopathology. Based on a review of previous studies and using confirmatory factor analyses (CFA), Wallwork et al. (Schizophr Res 2012; 137: 246-250) have recently proposed a consensus five-factor structure of the PANSS. This solution includes a cognitive factor which could be a useful measure of cognition in schizophrenia. Our objectives were 1) to study the psychometric properties (factorial structure and reliability) of this consensus five-factor model of the PANSS, and 2) to study the relationship between executive performance assessed using the Wisconsin Card Sorting Test (WCST) and the proposed PANSS consensus cognitive factor (composed by items P2-N5-G11). This cross-sectional study included a final sample of 201 Spanish outpatients diagnosed with schizophrenia. For our first objective, CFA was performed and Cronbach's alphas of the five factors were calculated; for the second objective, sequential linear regression analyses were used. The results of the CFA showed acceptable fit indices (NNFI=0.94, CFI=0.95, RMSEA=0.08). Cronbach's alphas of the five factors were adequate. Regression analyses showed that this five-factor model of the PANSS explained more of the WCST variance than the classical three-factor model. Moreover, higher cognitive factor scores were associated with worse WCST performance. These results supporting its factorial structure and reliability provide robustness to this consensus PANSS five-factor model, and indicate some usefulness of the cognitive factor in the clinical assessment of schizophrenic patients. Copyright © 2012 Elsevier B.V. All rights reserved.
Ionospheric Poynting Flux and Joule Heating Modeling Challenge: Latest Results and New Models.
Shim, J. S.; Rastaetter, L.; Kuznetsova, M. M.; Knipp, D. J.; Zheng, Y.; Cosgrove, R. B.; Newell, P. T.; Weimer, D. R.; Fuller-Rowell, T. J.; Wang, W.
2014-12-01
Poynting Flux and Joule Heating in the ionosphere - latest results from the challenge and updates at the CCMC. With the addition of satellite tracking and display features in the online analysis tool and at the Community Coordinated Modeling Center (CCMC), we are now able to obtain Poynting flux and Joule heating values from a wide variety of ionospheric models. In addition to Poynting fluxes derived from electric and magnetic field measurements from the Defense Meteorological Satellite Program (DMSP) satellites for a recent modeling challenge, we can now use a Poynting Flux model derived from FAST satellite observations for comparison. Poynting Fluxes are also correlated using Ovation Prime maps of precipitation patterns during the same time periods to assess how "typical" the events in the challenge are.
Factors associated with miscarriages: results of the 1999 Ukraine Reproductive Health Survey
Directory of Open Access Journals (Sweden)
Khomych, Liudmyla
2011-05-01
Full Text Available BACKGROUND. Miscarriages can be considered one of the most frequent problems that occur during pregnancy in humans. The frequency of cases among clinical pregnancies is about 12-15%. The determinants of the majority of miscarriages that occur are not wholly understood, and many putative risk factors remain controversial. The objective of this study was to explore the association of miscarriages with various socio-demographic and anamnestic factors in the Ukrainian population up to 1999.METHODS. In a case-control study nested in a cross-sectional survey, miscarriage was considered the outcome. The study data included 14 297 pregnancies of women of reproductive age (15-44 years old who participated in the 1999 Ukraine Reproductive Health Survey. Different socio-demographic and anamnestic factors were evaluated using multivariate logistic regression analysis to calculate adjusted odds ratios (AOR and 95% confidence intervals (CI.RESULTS. After adjustment for confounding, the following factors were independently associated with increased risk of having miscarriage at the p-level less than 0.05: year of the pregnancy after 1997 (AOR 1.72 95% CI 1,15–2,57, central regions of Ukraine (AOR 1,37 95% CI 1,00–1,88, high maternal age at first sexual intercourse (AOR 1,41 95% CI 1,03–1,92, ignorance of education level of the first sexual partner (AOR 2,29 95% CI 1,50–3,50, higher number of previous pregnancies (AOR 4,52 95% CI 1,70–12,02, inter-pregnancy interval 4-6 years (AOR 1,72 95% CI 1,14–2,59, and problems with getting pregnant (AOR 3,13 95% CI 2,55–3,84. Russian ethnicity (AOR 0,80 95% CI 0,66 – 0,97, being non-religious (AOR 0,76 95% CI 0,58 – 0,99, inter-pregnancy interval 15–18 months (AOR 0,60 95% CI 0,36 – 0,99 were associated with reduced risk of miscarriages. CONCLUSIONS. The results confirm that the higher inter-pregnancy interval and number of pregnancies, which can be related to older maternal age, are factors
Entrance and exit region friction factor models for annular seal analysis. Ph.D. Thesis
Elrod, David Alan
1988-01-01
The Mach number definition and boundary conditions in Nelson's nominally-centered, annular gas seal analysis are revised. A method is described for determining the wall shear stress characteristics of an annular gas seal experimentally. Two friction factor models are developed for annular seal analysis; one model is based on flat-plate flow theory; the other uses empirical entrance and exit region friction factors. The friction factor predictions of the models are compared to experimental results. Each friction model is used in an annular gas seal analysis. The seal characteristics predicted by the two seal analyses are compared to experimental results and to the predictions of Nelson's analysis. The comparisons are for smooth-rotor seals with smooth and honeycomb stators. The comparisons show that the analysis which uses empirical entrance and exit region shear stress models predicts the static and stability characteristics of annular gas seals better than the other analyses. The analyses predict direct stiffness poorly.
Institute of Scientific and Technical Information of China (English)
TONG Jin; SUN Ji-yu; CHEN Dong-hui; ZHANG Shu-jun
2004-01-01
The cuticle of dung beetle is a layered composite material in micro- or nano-scale. Dung beetle can fly, walk and dig. It can shovel and compact dung of mammals into balls. It use foreleg to walk, midleg and hindleg to hold and impel dung ball.Its two foreleges as digging legs are developed. The factors impacting the nanoindentation testing results of the femur cuticle of forelegs of dung beetle Copris ochus Motschulsky were examined. The nanomechanical test instrument used for the tests was Hysitron nanomechanical system. The results shown that the holding time and loading time are important factors impacting the accuracy of such indentation properties as reduced modulus (Er) and the harness ( H ) of the femur cuticle of the forelegs of dung beetle Copris ochus Motschulsky in nanoscale. There exists a threshold holding time of 20 s for the reduced modulus of the femur cuticle. The tests of nanoindentation creep property and the regression analysis of relationship between the depth increment at the maximum load and the time further confirmed the correction of the above threshold holding time.There exist visco-elastic-plastic behaviour and creep phenomenon in the femur cuticle during indenting. Its creep property during the holding procedure at maximum load can be regressed by a general logarithmic equation. The equation fitted by the testing data is △h = 54.834 52 ln(0.007 23t +1.004 86), where, △h is the depth increment at the maximum load and t is the time.
The Interpersonal Style Inventory and the five-factor model.
Lorr, M; Youniss, R P; Kluth, C
1992-03-01
The study examined relations between the 15 scale scores of the Interpersonal Style Inventory (Lorr & Youniss, 1985) and the domain measures of the five-factor model provided by the NEO Personality Inventory (Costa & McCrae, 1985). A sample of 236 college students were administered both inventories. A principal component analysis of the 5 NEO-PI domain scores and the 15 ISI scale scores followed by a Varimax rotation disclosed the expected five higher-order factors. Four factors, Neuroticism, Extraversion, Conscientiousness and Ageeableness, were defined by both NEO and ISI scales. Openness to Experience, however, was represented in the ISI by Independence and Directiveness, which define its Autonomy dimension. Thus, the ISI measures four of the five factors assessed by the NEO-PI.
Modeling Framework and Results to Inform Charging Infrastructure Investments
Energy Technology Data Exchange (ETDEWEB)
Melaina, Marc W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wood, Eric W [National Renewable Energy Laboratory (NREL), Golden, CO (United States)
2017-09-01
The plug-in electric vehicle (PEV) market is experiencing rapid growth with dozens of battery electric (BEV) and plug-in hybrid electric (PHEV) models already available and billions of dollars being invested by automotive manufacturers in the PEV space. Electric range is increasing thanks to larger and more advanced batteries and significant infrastructure investments are being made to enable higher power fast charging. Costs are falling and PEVs are becoming more competitive with conventional vehicles. Moreover, new technologies such as connectivity and automation hold the promise of enhancing the value proposition of PEVs. This presentation outlines a suite of projects funded by the U.S. Department of Energy's Vehicle Technology Office to conduct assessments of the economic value and charging infrastructure requirements of the evolving PEV market. Individual assessments include national evaluations of PEV economic value (assuming 73M PEVs on the road in 2035), national analysis of charging infrastructure requirements (with community and corridor level resolution), and case studies of PEV ownership in Columbus, OH and Massachusetts.
Social approval of the community assessment model for odor dispersal: results from a citizen survey.
Tyndall, John C; Grudens-Schuck, Nancy; Harmon, Jay D; Hoff, Steve J
2012-08-01
Odors emitted from US Midwest hog production facilities present farmers, residents, and state regulatory agencies with a set of complex challenges. To predict odor exposure from multiple swine production sources simultaneously, and to determine siting recommendations for proposed new or enlarged hog facilities, researchers at Iowa State University designed the community assessment model for odor dispersion (CAM). A three-county citizen survey conducted in Iowa examined the level of hypothetical social acceptance of the modeling process, and level of trust in CAM results. While 69 % of respondents approved of modeling as a way to determine the most socially appropriate location for production sites, only 35 % would trust the results if potential odor exposure from a new facility were proposed to be built near their home. We analyzed approval of the CAM model, and level of trust, across a number of demographic, attitudinal, and belief factors regarding environmental quality and the hog industry. Overall, trust in CAM was uneven and varied across respondents. Those residents who would not trust CAM tended to be more concerned with environmental quality and less inclined to believe that the hog industry is critically important economically. Those who would not trust CAM results also had significantly more direct experience with odors. Findings point to predominantly positive, yet equivocal acceptance of CAM results among the citizenry, which is not unexpected given conflict typical of siting decisions in industry and waste disposal arenas. Recommendations are offered regarding the interaction of trust, beliefs and attitudes and the utility of CAM.
Scherstjanoi, M.; Kaplan, J. O.; Lischke, H.
2014-07-01
To be able to simulate climate change effects on forest dynamics over the whole of Switzerland, we adapted the second-generation DGVM (dynamic global vegetation model) LPJ-GUESS (Lund-Potsdam-Jena General Ecosystem Simulator) to the Alpine environment. We modified model functions, tuned model parameters, and implemented new tree species to represent the potential natural vegetation of Alpine landscapes. Furthermore, we increased the computational efficiency of the model to enable area-covering simulations in a fine resolution (1 km) sufficient for the complex topography of the Alps, which resulted in more than 32 000 simulation grid cells. To this aim, we applied the recently developed method GAPPARD (approximating GAP model results with a Probabilistic Approach to account for stand Replacing Disturbances) (Scherstjanoi et al., 2013) to LPJ-GUESS. GAPPARD derives mean output values from a combination of simulation runs without disturbances and a patch age distribution defined by the disturbance frequency. With this computationally efficient method, which increased the model's speed by approximately the factor 8, we were able to faster detect the shortcomings of LPJ-GUESS functions and parameters. We used the adapted LPJ-GUESS together with GAPPARD to assess the influence of one climate change scenario on dynamics of tree species composition and biomass throughout the 21st century in Switzerland. To allow for comparison with the original model, we additionally simulated forest dynamics along a north-south transect through Switzerland. The results from this transect confirmed the high value of the GAPPARD method despite some limitations towards extreme climatic events. It allowed for the first time to obtain area-wide, detailed high-resolution LPJ-GUESS simulation results for a large part of the Alpine region.
Directory of Open Access Journals (Sweden)
Pilar Suñé
Full Text Available OBJECTIVES: Publication bias may affect the validity of evidence based medical decisions. The aim of this study is to assess whether research outcomes affect the dissemination of clinical trial findings, in terms of rate, time to publication, and impact factor of journal publications. METHODS AND FINDINGS: All drug-evaluating clinical trials submitted to and approved by a general hospital ethics committee between 1997 and 2004 were prospectively followed to analyze their fate and publication. Published articles were identified by searching Pubmed and other electronic databases. Clinical study final reports submitted to the ethics committee, final reports synopses available online and meeting abstracts were also considered as sources of study results. Study outcomes were classified as positive (when statistical significance favoring experimental drug was achieved, negative (when no statistical significance was achieved or it favored control drug and descriptive (for non-controlled studies. Time to publication was defined as time from study closure to publication. A survival analysis was performed using a Cox regression model to analyze time to publication. Journal impact factors of identified publications were recorded. Publication rate was 48·4% (380/785. Study results were identified for 68·9% of all completed clinical trials (541/785. Publication rate was 84·9% (180/212 for studies with results classified as positive and 68·9% (128/186 for studies with results classified as negative (p<0·001. Median time to publication was 2·09 years (IC95 1·61-2·56 for studies with results classified as positive and 3·21 years (IC95 2·69-3·70 for studies with results classified as negative (hazard ratio 1·99 (IC95 1·55-2·55. No differences were found in publication impact factor between positive (median 6·308, interquartile range: 3·141-28·409 and negative result studies (median 8·266, interquartile range: 4·135-17·157. CONCLUSIONS
A New European Slope Length and Steepness Factor (LS-Factor for Modeling Soil Erosion by Water
Directory of Open Access Journals (Sweden)
Panos Panagos
2015-04-01
Full Text Available The Universal Soil Loss Equation (USLE model is the most frequently used model for soil erosion risk estimation. Among the six input layers, the combined slope length and slope angle (LS-factor has the greatest influence on soil loss at the European scale. The S-factor measures the effect of slope steepness, and the L-factor defines the impact of slope length. The combined LS-factor describes the effect of topography on soil erosion. The European Soil Data Centre (ESDAC developed a new pan-European high-resolution soil erosion assessment to achieve a better understanding of the spatial and temporal patterns of soil erosion in Europe. The LS-calculation was performed using the original equation proposed by Desmet and Govers (1996 and implemented using the System for Automated Geoscientific Analyses (SAGA, which incorporates a multiple flow algorithm and contributes to a precise estimation of flow accumulation. The LS-factor dataset was calculated using a high-resolution (25 m Digital Elevation Model (DEM for the whole European Union, resulting in an improved delineation of areas at risk of soil erosion as compared to lower-resolution datasets. This combined approach of using GIS software tools with high-resolution DEMs has been successfully applied in regional assessments in the past, and is now being applied for first time at the European scale.
Standard Model Higgs results from ATLAS and CMS experiments
AUTHOR|(INSPIRE)INSPIRE-00221190; The ATLAS collaboration
2016-01-01
The properties of the Higgs boson particle were measured with the ATLAS and CMS experiments at the LHC at the centre-of-mass energies 7 TeV and 8 TeV. The combined data samples of the ATLAS and CMS experiments were used for the measurements of the Higgs boson mass and couplings. Furthermore, the CP and spin analysis done separately with the CMS and ATLAS experiments are described. Moreover, first results of the Higgs boson cross section at the centre-of-mass energy 13 TeV in the channels H->ZZ->4leptons and H->gamma+gamma with the ATLAS detector are presented.
A Diquark-Quark Model with Its Use in Nucleon Form Factors
Institute of Scientific and Technical Information of China (English)
WANG Hong-Min; ZHANG Ben-Ai
2005-01-01
The nucleon electromagnetic form factors are investigated within a simple diquark-quark model using the light-front formalism. In this model, baryon is described as a bound state of one quark and one clustering diquark.The calculational results are compared with the experimental ones. We also regard the quarks in a baryon as pointlike constituent quarks.
Enhancement Factors in Ozone Absorption Based on the Surface Renewal Model and its Application
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
Based on the Danckwerts surface renewal model, a simple explicit expression of theenhancement factor in ozone absorption with a first order ozone self-decomposition and parallel secondorder ozonation reactions has been derived. The results are compared with our previous work based onthe film theory. The 2,4-dichlorophenol destruction rate by ozonation is predicted using the enhancementfactor model in this paper.
Directory of Open Access Journals (Sweden)
Mark D Huffman
2015-01-01
Full Text Available Background & objectives: Abnormal endothelial function represents a preclinical marker of atherosclerosis. This study was conducted to evaluate associations between anthropometry, cardiometabolic risk factors, and early life factors and adult measures of endothelial function in a young urban Indian cohort free of clinical cardiovascular disease. Methods: Absolute changes in brachial artery diameter following cuff inflation and sublingual nitroglycerin (400 µg were recorded to evaluate endothelium-dependent and -independent measures of endothelial function in 600 participants (362 men; 238 women from the New Delhi Birth Cohort (2006-2009. Data on anthropometry, cardiometabolic risk factors, medical history, socio-economic position, and lifestyle habits were collected. Height and weight were recorded at birth, two and 11 yr of age. Age- and sex-adjusted linear regression models were developed to evaluate these associations. Results: The mean age of participants was 36±1 yr. Twenty two per cent men and 29 per cent women were obese (BMI th > 30 kg/m [2] . Mean systolic blood pressure (SBP was 131±14 and 119±13 mmHg, and diabetes prevalence was 12 and 8 per cent for men and women, respectively. Brachial artery diameter was higher for men compared with women both before (3.48±0.37 and 2.95±0.35 cm and after hyperaemia (3.87±0.37 vs. 3.37±0.35 cm. A similar difference was seen before and after nitroglycerin. Markers of increased adiposity, smoking, SBP, and metabolic syndrome, but not early life anthropometry, were inversely associated with endothelial function after adjustment for age and sex. Interpretation & conclusions: The analysis of the current prospective data from a young urban Indian cohort showed that cardiometabolic risk factors, but not early life anthropometry, were associated with worse endothelial function.
Two Empirical Models for Land-falling Hurricane Gust Factors
Merceret, Franics J.
2008-01-01
Gaussian and lognormal models for gust factors as a function of height and mean windspeed in land-falling hurricanes are presented. The models were empirically derived using data from 2004 hurricanes Frances and Jeanne and independently verified using data from 2005 hurricane Wilma. The data were collected from three wind towers at Kennedy Space Center and Cape Canaveral Air Force Station with instrumentation at multiple levels from 12 to 500 feet above ground level. An additional 200-foot tower was available for the verification. Mean wind speeds from 15 to 60 knots were included in the data. The models provide formulas for the mean and standard deviation of the gust factor given the mean windspeed and height above ground. These statistics may then be used to assess the probability of exceeding a specified peak wind threshold of operational significance given a specified mean wind speed.
TEST OF THE FAMA-FRENCH THREE-FACTOR MODEL IN CROATIA
Directory of Open Access Journals (Sweden)
Denis Dolinar
2013-06-01
Full Text Available This paper empirically examines the Fama-French three-factor model of stock returns for Croatia. In contrast to the results of Fama and French (1993 for the U.S. stock market, their three-factor model did not show so successful when describing risk-return relation of Croatian stocks. This paper shows that the Fama-French three-factor model is a valid pricing model, since it explains cross-section of average returns on stocks in Croatia, and that has a greater explanatory power in comparison to the CAPM. In the case of Croatian stock market, size and B/M factors are not always significant, but on average they individually have certain marginal explanatory power. Namely, they capture small common variation in returns that is missed by the market factor. Moreover, B/M factor has shown as a stronger common risk proxy in relation to size factor. Finally, there is still a large portion of common variation in stock return that may be explained by other factors. Because emerging capital markets bear their own specificity, special care needs to be taken when applying existing or developing new pricing models.
Stress Resultant Based Elasto-Viscoplastic Thick Shell Model
Directory of Open Access Journals (Sweden)
Pawel Woelke
2012-01-01
Full Text Available The current paper presents enhancement introduced to the elasto-viscoplastic shell formulation, which serves as a theoretical base for the finite element code EPSA (Elasto-Plastic Shell Analysis [1–3]. The shell equations used in EPSA are modified to account for transverse shear deformation, which is important in the analysis of thick plates and shells, as well as composite laminates. Transverse shear forces calculated from transverse shear strains are introduced into a rate-dependent yield function, which is similar to Iliushin's yield surface expressed in terms of stress resultants and stress couples [12]. The hardening rule defined by Bieniek and Funaro [4], which allows for representation of the Bauschinger effect on a moment-curvature plane, was previously adopted in EPSA and is used here in the same form. Viscoplastic strain rates are calculated, taking into account the transverse shears. Only non-layered shells are considered in this work.
High-energy radiation damage in zirconia: modeling results
Energy Technology Data Exchange (ETDEWEB)
Zarkadoula, Eva; Devanathan, Ram; Weber, William J.; Seaton, Michael; Todorov, Ilian; Nordlund, Kai; Dove, Martin T.; Trachenko, Kostya
2014-02-28
Zirconia has been viewed as a material of exceptional resistance to amorphization by radiation damage, and was consequently proposed as a candidate to immobilize nuclear waste and serve as a nuclear fuel matrix. Here, we perform molecular dynamics simulations of radiation damage in zirconia in the range of 0.1-0.5 MeV energies with the account of electronic energy losses. We find that the lack of amorphizability co-exists with a large number of point defects and their clusters. These, importantly, are largely disjoint from each other and therefore represent a dilute damage that does not result in the loss of long-range structural coherence and amorphization. We document the nature of these defects in detail, including their sizes, distribution and morphology, and discuss practical implications of using zirconia in intense radiation environments.
High-energy radiation damage in zirconia: modeling results
Energy Technology Data Exchange (ETDEWEB)
Zarkadoula, Evangelia [Queen Mary, University of London; Devanathan, Ram [Pacific Northwest National Laboratory (PNNL); Weber, William J [ORNL; Seaton, M [Daresbury Laboratory, UK; Todorov, I T [Daresbury Laboratory, UK; Nordlund, Kai [University of Helsinki; Dove, Martin T [Queen Mary, University of London; Trachenko, Kostya [Queen Mary, University of London
2014-01-01
Zirconia is viewed as a material of exceptional resistance to amorphization by radiation damage, and consequently proposed as a candidate to immobilize nuclear waste and serve as an inert nuclear fuel matrix. Here, we perform molecular dynamics simulations of radiation damage in zirconia in the range of 0.1-0.5 MeV energies with account of electronic energy losses. We nd that the lack of amorphizability co-exists with a large number of point defects and their clusters. These, importantly, are largely isolated from each other and therefore represent a dilute damage that does not result in the loss of long-range structural coherence and amorphization. We document the nature of these defects in detail, including their sizes, distribution and morphology, and discuss practical implications of using zirconia in intense radiation environments.
High-energy radiation damage in zirconia: Modeling results
Energy Technology Data Exchange (ETDEWEB)
Zarkadoula, E., E-mail: zarkadoulae@ornl.gov [School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); SEPnet, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Devanathan, R. [Nuclear Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States); Weber, W. J. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Seaton, M. A.; Todorov, I. T. [STFC Daresbury Laboratory, Scientific Computing Department, Keckwick Lane, Daresbury, Warrington, Cheshire WA4 4AD (United Kingdom); Nordlund, K. [University of Helsinki, P.O. Box 43, FIN-00014 Helsinki (Finland); Dove, M. T. [School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Trachenko, K. [School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); SEPnet, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom)
2014-02-28
Zirconia is viewed as a material of exceptional resistance to amorphization by radiation damage, and consequently proposed as a candidate to immobilize nuclear waste and serve as an inert nuclear fuel matrix. Here, we perform molecular dynamics simulations of radiation damage in zirconia in the range of 0.1–0.5 MeV energies with account of electronic energy losses. We find that the lack of amorphizability co-exists with a large number of point defects and their clusters. These, importantly, are largely isolated from each other and therefore represent a dilute damage that does not result in the loss of long-range structural coherence and amorphization. We document the nature of these defects in detail, including their sizes, distribution, and morphology, and discuss practical implications of using zirconia in intense radiation environments.
Alexander, Jennifer; Barham, Philip; Black, Ian
2002-11-01
Using data generated from a fixed-base interactive driving simulator, which was used to evaluate a driver decision aid, a model is built to predict the probability of an incident (i.e. an accident or a 'near miss') occurring as a result of a right-turn across left-hand traffic at an unsignalised junction. This can be considered to be the product of two separate probabilities, the first being the probability that the gap between a pair of vehicles in the traffic stream is accepted, and the second the probability that the time needed to cross the on-coming stream of traffic causes the time-to-collision with the nearest vehicle in this traffic stream to be less than a second. The model is developed from the results of experimental trials involving a sample of drivers, the majority of whom were aged 60 years or older, in order to demonstrate the effect of various parameters on these probabilities. The parameters considered include the size of the gap between successive vehicles, vehicle characteristics such as size, colour and velocity, driver characteristics such as age and sex, and both daytime and night-time conditions.
Bruner, Anne M.; Belvin, W. Keith; Horta, Lucas G.; Juang, Jer-Nan
1991-01-01
The development of control of large flexible structures technology must include practical demonstrations to aid in the understanding and characterization of controlled structures in space. To support this effort, a testbed facility has been developed to study practical implementation of new control technologies under realistic conditions. The paper discusses the design of a second order, acceleration feedback controller which acts as an active vibration absorber. This controller provides guaranteed stability margins for collocated sensor/actuator pairs in the absence of sensor/actuator dynamics and computational time delay. Experimental results in the presence of these factors are presented and discussed. The robustness of this design under model uncertainty is demonstrated.
Smith, Martin M; Saklofske, Donald H
2016-08-05
Evidence suggests perfectionism is a multidimensional construct composed of 2 higher order factors: perfectionistic strivings and perfectionistic concerns. However, the substantial overlap between perfectionistic strivings and perfectionistic concerns is problematic, as are the unanswered questions regarding the structure of perfectionism following removal of common variance. This research addressed this through bifactor modeling. Three student samples (N = 742) completed Hewitt and Flett's ( 1991 ) Multidimensional Perfectionism Scale, Frost, Marten, Lahart, and Rosenblate's ( 1990 ) Multidimensional Perfectionism Scale, and Slaney, Rice, Mobley, Trippi, and Ashby's ( 2001 ) Almost Perfect Scale-Revised. Greater support was consistently found for the bifactor model, relative to the 2-factor model. Results suggest the bifactor model best represents the structure of perfectionism and provide preliminary support for the use of a general factor score. Researchers are cautioned that removal of general variance may render the reliability of specific factors (i.e., perfectionistic strivings and perfectionistic concerns) suspect.
Smoking as a risk factor of multiple sclerosis: results of cohort study in volyn region
Directory of Open Access Journals (Sweden)
Ольга Дмитрівна Шульга
2016-01-01
Full Text Available Smoking is the modified risk factor of the multiple sclerosis (MS development. In spite of the low smoking percentage in the population of Volyn region the rates of MS prevalence and morbidity is there the one of the highest in the country.Aim of research: to assess an influence of smoking in Volyn dwellers on the type of clinical course, progression quickness and the incapability degree in patients with MS.Materials and methods: According to the smoking status all patients were divided into three groups: smokers, ex-smokers, non-smokers. There were assessed age, sexual differences, the age of the debut of disease, neurological deficiency degree, the disease progression quickness between groups. Statistical analysis was carried out with the help of Microsoft Excel, SPSS program for Windows using the standard descriptive statistics, correlative and regressive analysis. For analysis of events achievement there were used the plural assessments of Kaplan-Meier. The comparison of survival functions in two groups was carried out using Cox and Wilkinson F-criterion.Results: There were examined 338 patients with multiple sclerosis from all districts of Volyn region among them – 220 (65,1 % women. The men-women ratio was 1,87:1. The mean age of patients was 47±12,18 years old, the age of the MS first symptoms appearance– 30±9,19 years old. The age of patients at the time of diagnosis– 33±9,4 years old. The mean grade on EDSS scale – 4±2,04. There was established that patients in the group of smokers were younger, the first symptoms appeared earlier compared with those who never smoked or stopped smoking (p<0,05. The disability level on EDSS scale was lower in the group of patients who never smoked (p=0,015. There was not revealed the statistically significant difference for the next rates: the type of clinical course, type of debut of disease and progression quickness of disease.Conclusion: The MS appears earlier in smoking patients. The
Directory of Open Access Journals (Sweden)
Evgeniy A Ozonov
Full Text Available Because DNA packaging in nucleosomes modulates its accessibility to transcription factors (TFs, unraveling the causal determinants of nucleosome positioning is of great importance to understanding gene regulation. Although there is evidence that intrinsic sequence specificity contributes to nucleosome positioning, the extent to which other factors contribute to nucleosome positioning is currently highly debated. Here we obtained both in vivo and in vitro reference maps of positions that are either consistently covered or free of nucleosomes across multiple experimental data-sets in Saccharomyces cerevisiae. We then systematically quantified the contribution of TF binding to nucleosome positioning using a rigorous statistical mechanics model in which TFs compete with nucleosomes for binding DNA. Our results reconcile previous seemingly conflicting results on the determinants of nucleosome positioning and provide a quantitative explanation for the difference between in vivo and in vitro positioning. On a genome-wide scale, nucleosome positioning is dominated by the phasing of nucleosome arrays over gene bodies, and their positioning is mainly determined by the intrinsic sequence preferences of nucleosomes. In contrast, larger nucleosome free regions in promoters, which likely have a much more significant impact on gene expression, are determined mainly by TF binding. Interestingly, of the 158 yeast TFs included in our modeling, we find that only 10-20 significantly contribute to inducing nucleosome-free regions, and these TFs are highly enriched for having direct interactions with chromatin remodelers. Together our results imply that nucleosome free regions in yeast promoters results from the binding of a specific class of TFs that recruit chromatin remodelers.
Ozonov, Evgeniy A; van Nimwegen, Erik
2013-01-01
Because DNA packaging in nucleosomes modulates its accessibility to transcription factors (TFs), unraveling the causal determinants of nucleosome positioning is of great importance to understanding gene regulation. Although there is evidence that intrinsic sequence specificity contributes to nucleosome positioning, the extent to which other factors contribute to nucleosome positioning is currently highly debated. Here we obtained both in vivo and in vitro reference maps of positions that are either consistently covered or free of nucleosomes across multiple experimental data-sets in Saccharomyces cerevisiae. We then systematically quantified the contribution of TF binding to nucleosome positioning using a rigorous statistical mechanics model in which TFs compete with nucleosomes for binding DNA. Our results reconcile previous seemingly conflicting results on the determinants of nucleosome positioning and provide a quantitative explanation for the difference between in vivo and in vitro positioning. On a genome-wide scale, nucleosome positioning is dominated by the phasing of nucleosome arrays over gene bodies, and their positioning is mainly determined by the intrinsic sequence preferences of nucleosomes. In contrast, larger nucleosome free regions in promoters, which likely have a much more significant impact on gene expression, are determined mainly by TF binding. Interestingly, of the 158 yeast TFs included in our modeling, we find that only 10-20 significantly contribute to inducing nucleosome-free regions, and these TFs are highly enriched for having direct interactions with chromatin remodelers. Together our results imply that nucleosome free regions in yeast promoters results from the binding of a specific class of TFs that recruit chromatin remodelers.
Laanani, Moussa; Dozol, Adrien; Meyer, Laurence; David, Stéphane; Camara, Sékou; Segouin, Christophe; Troude, Pénélope
2015-07-01
Free and anonymous screening centres (CDAG: Centres de Depistage Anononyme et Gratuit) are public facilities set up for HIV infection diagnosis in France. Some people visiting CDAG fail to return for test results and are not informed of their serology. This study aimed to assess factors associated with failure to return for HIV test results. Patients visiting the Fernand-Widal CDAG (Paris) for an HIV test in January-February 2011 were eligible to take part in the study. Data were collected with an anonymous self-administered questionnaire. Factors associated with failure to return were assessed using logistic regression models. Of the 710 participants (participation rate 88%), 46 patients failed to return. Not specifying birthplace and not living in the region of Paris were associated with failure to return. Those who perceived no risk of HIV infection and those who felt they were more at risk than other people were both statistically associated with failure to return. Self-perceived risk seemed to be of chief concern for failure to return for HIV test results and should be considered during pre-test counselling.
Directory of Open Access Journals (Sweden)
Christopher Pell
Full Text Available BACKGROUND: Antenatal care (ANC is a key strategy to improve maternal and infant health. However, survey data from sub-Saharan Africa indicate that women often only initiate ANC after the first trimester and do not achieve the recommended number of ANC visits. Drawing on qualitative data, this article comparatively explores the factors that influence ANC attendance across four sub-Saharan African sites in three countries (Ghana, Kenya and Malawi with varying levels of ANC attendance. METHODS: Data were collected as part of a programme of qualitative research investigating the social and cultural context of malaria in pregnancy. A range of methods was employed interviews, focus groups with diverse respondents and observations in local communities and health facilities. RESULTS: Across the sites, women attended ANC at least once. However, their descriptions of ANC were often vague. General ideas about pregnancy care - checking the foetus' position or monitoring its progress - motivated women to attend ANC; as did, especially in Kenya, obtaining the ANC card to avoid reprimands from health workers. Women's timing of ANC initiation was influenced by reproductive concerns and pregnancy uncertainties, particularly during the first trimester, and how ANC services responded to this uncertainty; age, parity and the associated implications for pregnancy disclosure; interactions with healthcare workers, particularly messages about timing of ANC; and the cost of ANC, including charges levied for ANC procedures - in spite of policies of free ANC - combined with ideas about the compulsory nature of follow-up appointments. CONCLUSION: In these socially and culturally diverse sites, the findings suggest that 'supply' side factors have an important influence on ANC attendance: the design of ANC and particularly how ANC deals with the needs and concerns of women during the first trimester has implications for timing of initiation.
Pell, Christopher; Meñaca, Arantza; Were, Florence; Afrah, Nana A.; Chatio, Samuel; Manda-Taylor, Lucinda; Hamel, Mary J.; Hodgson, Abraham; Tagbor, Harry; Kalilani, Linda; Ouma, Peter; Pool, Robert
2013-01-01
Background Antenatal care (ANC) is a key strategy to improve maternal and infant health. However, survey data from sub-Saharan Africa indicate that women often only initiate ANC after the first trimester and do not achieve the recommended number of ANC visits. Drawing on qualitative data, this article comparatively explores the factors that influence ANC attendance across four sub-Saharan African sites in three countries (Ghana, Kenya and Malawi) with varying levels of ANC attendance. Methods Data were collected as part of a programme of qualitative research investigating the social and cultural context of malaria in pregnancy. A range of methods was employed interviews, focus groups with diverse respondents and observations in local communities and health facilities. Results Across the sites, women attended ANC at least once. However, their descriptions of ANC were often vague. General ideas about pregnancy care – checking the foetus’ position or monitoring its progress – motivated women to attend ANC; as did, especially in Kenya, obtaining the ANC card to avoid reprimands from health workers. Women’s timing of ANC initiation was influenced by reproductive concerns and pregnancy uncertainties, particularly during the first trimester, and how ANC services responded to this uncertainty; age, parity and the associated implications for pregnancy disclosure; interactions with healthcare workers, particularly messages about timing of ANC; and the cost of ANC, including charges levied for ANC procedures – in spite of policies of free ANC – combined with ideas about the compulsory nature of follow-up appointments. Conclusion In these socially and culturally diverse sites, the findings suggest that ‘supply’ side factors have an important influence on ANC attendance: the design of ANC and particularly how ANC deals with the needs and concerns of women during the first trimester has implications for timing of initiation. PMID:23335973
Näsilä, Antti; Holmlund, Christer; Mannila, Rami; Näkki, Ismo; Ojanen, Harri J.; Akujärvi, Altti; Saari, Heikki; Fussen, Didier; Pieroux, Didier; Demoulin, Philippe
2016-10-01
PICASSO - A PICo-satellite for Atmospheric and Space Science Observations is an ESA project led by the Belgian Institute for Space Aeronomy, in collaboration with VTT Technical Research Centre of Finland Ltd, Clyde Space Ltd. (UK) and Centre Spatial de Liège (BE). The test campaign for the engineering model of the PICASSO VISION instrument, a miniaturized nanosatellite spectral imager, has been successfully completed. The test results look very promising. The proto-flight model of VISION has also been successfully integrated and it is waiting for the final integration to the satellite platform.
[Risk factors for uterine cervical cancer according to results of VIA, cytology and cervicography].
dos Anjos, Saiwori de Jesus Silva Bezerra; Vasconcelos, Camila Teixeira Moreira; Franco, Eugênio Santana; de Almeida, Paulo César; Pinheiro, Ana Karina Bezerra
2010-12-01
This study aimed to evaluate the association between risk factors for uterine cervical neoplasms and cervical lesions by HPV by comparison of the visual inspection with acetic acid (VIA), cytology and cervicography results. A prevalence research was made with 157 women in a health center of Fortaleza in the period of June to September 2006. The SPSS program was used to codify the data. Inferences were made through statistical tests (chi2 = chi square and LR = likelihood ratio). The VIA, cervicography and cytology obtained 43.3%, 10.19% and 3.2% of altered results. The variables with important association to cervical lesions in the VIA were: aged less than 20 years old (p = 0.0001); one or more partners in the last three months (p = 0.015); use of contraceptives (p = 0.0008); presence of vaginal discharge (p = 0.0001) and moderate or accentuated inflammatory process (p = 0.0001). In the cytology: low instructional level (p = 0.0001) and high pH (p = 0.001). It wasn't found any significant association in the cervicography.
Helgeson, Melvin D; Potter, Benjamin K; Burns, Travis C; Hayda, Roman A; Gajewski, Donald A
2010-09-07
We studied patients with combat-related injuries that required delayed amputation at least 4 months after the initial injury due to dysfunction, persistent pain, and patient desires. Late amputations were performed 22 times in 22 patients (21 men, 1 woman) since 2003. Fourteen patients underwent transtibial amputation, 5 transfemoral amputations, 1 knee disarticulation, and 2 transradial amputations. The primary indications for late amputation were neurologic dysfunction in 6 patients, persistent or recurrent infection in 6, neurogenic pain in 3, non-neurogenic pain in 5, and a globally poor functional result in 2. Sixteen of 22 patients reported multiple indications for electing to undergo amputation, with an average of 2.1 specific indications per patient. At final clinical follow-up an average of 13 months after amputation, all patients reported subjectively improved function and reported that they would undergo amputation again under similar circumstances. When medically and functionally practicable, every effort is given to limb salvage following severe combat-related extremity injuries. There is no single risk factor that increases the likelihood of delayed amputation, but the combination of complex pain symptoms with neurologic dysfunction appears to increase the risk, particularly if the initial insult is a severe hindfoot injury or distal tibia fracture. With appropriately selected and counseled patients, elective late amputation results in a high degree of patient satisfaction and subjectively improved function.
Krueger, Aaron B; Carnell, Pauline; Carpenter, John F
2016-04-01
In many manufacturing and research areas, the ability to accurately monitor and characterize nanoparticles is becoming increasingly important. Nanoparticle tracking analysis is rapidly becoming a standard method for this characterization, yet several key factors in data acquisition and analysis may affect results. Nanoparticle tracking analysis is prone to user input and bias on account of a high number of parameters available, contains a limited analysis volume, and individual sample characteristics such as polydispersity or complex protein solutions may affect analysis results. This study systematically addressed these key issues. The integrated syringe pump was used to increase the sample volume analyzed. It was observed that measurements recorded under flow caused a reduction in total particle counts for both polystyrene and protein particles compared to those collected under static conditions. In addition, data for polydisperse samples tended to lose peak resolution at higher flow rates, masking distinct particle populations. Furthermore, in a bimodal particle population, a bias was seen toward the larger species within the sample. The impacts of filtration on an agitated intravenous immunoglobulin sample and operating parameters including "MINexps" and "blur" were investigated to optimize the method. Taken together, this study provides recommendations on instrument settings and sample preparations to properly characterize complex samples.
Modelling combustion reactions for gas flaring and its resulting emissions
Directory of Open Access Journals (Sweden)
O. Saheed Ismail
2016-07-01
Full Text Available Flaring of associated petroleum gas is an age long environmental concern which remains unabated. Flaring of gas maybe a very efficient combustion process especially steam/air assisted flare and more economical than utilization in some oil fields. However, it has serious implications for the environment. This study considered different reaction types and operating conditions for gas flaring. Six combustion equations were generated using the mass balance concept with varying air and combustion efficiency. These equations were coded with a computer program using 12 natural gas samples of different chemical composition and origin to predict the pattern of emission species from gas flaring. The effect of key parameters on the emission output is also shown. CO2, CO, NO, NO2 and SO2 are the anticipated non-hydrocarbon emissions of environmental concern. Results show that the quantity and pattern of these chemical species depended on percentage excess/deficiency of stoichiometric air, natural gas type, reaction type, carbon mass content, impurities, combustion efficiency of the flare system etc. These emissions degrade the environment and human life, so knowing the emission types, pattern and flaring conditions that this study predicts is of paramount importance to governments, environmental agencies and the oil and gas industry.
Modelling of a water plasma flow: I. Basic results
Energy Technology Data Exchange (ETDEWEB)
KotalIk, Pavel [INP Greifswald, Friedrich-Ludwig-Jahn-Strasse 19, 17489 Greifswald (Germany)
2006-06-21
One-fluid MHD equations are numerically solved for an axisymmetric flow of thermal water plasma inside and outside a discharge chamber of a plasma torch with water vortex stabilization of electric arc. Comparisons with experimental data and previous calculations are given. For arc currents of 300-600 A, the respective temperatures and velocities in the range 16 700-26 400 K and 2300-6900 m s{sup -1} are obtained at the centre of the nozzle exit. The flow velocity on axis increases by 1-2 km s{sup -1} in the 5 mm long nozzle. Ohmic heating and radiative losses are two competitive processes influencing most the plasma temperature and velocity. The radiative losses represent 39% to 46% of the torch power of 69-174 kW when optical thickness of 3 mm is assumed for the plasma column. In front of the cathode, inside the discharge chamber, a recirculation zone is predicted and discussed. Effects of the temperature dependence of the plasma viscosity and sound velocity and of the optical thickness are examined. It is shown that the results such as waviness of the Mach number isolines are direct consequences of these dependences. Different lengths of 55 and 60 mm of the water vortex stabilized part of the electric arc do not substantially influence the plasma temperature and velocity at the nozzle exit.
A latent profile analysis of the Five Factor Model of personality: Modeling trait interactions.
Merz, Erin L; Roesch, Scott C
2011-12-01
Interactions among the dimensions of the Five Factor Model (FFM) have not typically been evaluated in mental health research, with the extant literature focusing on bivariate relationships with psychological constructs of interest. This study used latent profile analysis to mimic higher-order interactions to identify homogenous personality profiles using the FFM, and also examined relationships between resultant profiles and affect, self-esteem, depression, anxiety, and coping efficacy. Participants (N = 371) completed self-report and daily diary questionnaires. A 3-profile solution provided the best fit to the data; the profiles were characterized as well-adjusted, reserved, and excitable. The well-adjusted group reported better psychological functioning in validation analyses. The reserved and excitable groups differed on anxiety, with the excitable group reporting generally higher anxiety than the reserved group. Latent profile analysis may be a parsimonious way to model personality heterogeneity.
An information transmission model for transcription factor binding at regulatory DNA sites.
Tan, Mingfeng; Yu, Dong; Jin, Yuan; Dou, Lei; Li, Beiping; Wang, Yuelan; Yue, Junjie; Liang, Long
2012-06-06
Computational identification of transcription factor binding sites (TFBSs) is a rapid, cost-efficient way to locate unknown regulatory elements. With increased potential for high-throughput genome sequencing, the availability of accurate computational methods for TFBS prediction has never been as important as it currently is. To date, identifying TFBSs with high sensitivity and specificity is still an open challenge, necessitating the development of novel models for predicting transcription factor-binding regulatory DNA elements. Based on the information theory, we propose a model for transcription factor binding of regulatory DNA sites. Our model incorporates position interdependencies in effective ways. The model computes the information transferred (TI) between the transcription factor and the TFBS during the binding process and uses TI as the criterion to determine whether the sequence motif is a possible TFBS. Based on this model, we developed a computational method to identify TFBSs. By theoretically proving and testing our model using both real and artificial data, we found that our model provides highly accurate predictive results. In this study, we present a novel model for transcription factor binding regulatory DNA sites. The model can provide an increased ability to detect TFBSs.
Self-pathology, the five-factor model, and bloated specific factors: A cautionary tale.
Oltmanns, Joshua R; Widiger, Thomas A
2016-04-01
The five-factor model (FFM) is widely regarded as a useful model for the structure of both normal and maladaptive personality traits. However, recent factor analytic studies have suggested that deficits in the sense of self fall outside the FFM. The current study replicates and extends these findings, illustrating that factors can be situated outside a higher-order domain by including a relatively large number of closely related scales, forming what is known as a bloated specific factor. A total of 1,553 participants (M age = 37.8 years, SD = 13.1) were recruited across 3 studies. One measure of self-pathology (including 15 scales) and 2 measures of the FFM were administered, along with 17 measures of anxiousness and 12 measures of social withdrawal/sociability. Across 2 independent samples and 2 different measures of the FFM, deficits in the sense of self separated from neuroticism when all 15 scales of self-pathology were included. However, self-pathology loaded with FFM neuroticism when only a subset of the self-pathology scales was included. This finding was replicated with measures of social withdrawal/sociability, although only partially replicated with measures of anxiousness. Implications of these findings for past and future factor analytic studies of the structure of psychopathology are discussed.
Directory of Open Access Journals (Sweden)
Nasir Abbas
2012-01-01
Full Text Available Normal 0 false false false MicrosoftInternetExplorer4 Normal 0 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} The results of sport contests depend upon a lot. In this article, an attempt is made to accommodate the factors influencing the sports-results by proposing a model for paired comparison experiments that splits the order effect into its components. The proposed model can be used to study the effects of all the components of the order effect separately. For instance, we study only two components of the order effect. The maximum likelihood estimates of the worth parameters are found and the plausibility of the proposed model is checked. Real data set is collected on five top-ranked one-day-international cricket teams and is used to illustrate the estimation procedure.
Learning Hidden Markov Models using Non-Negative Matrix Factorization
Cybenko, George
2008-01-01
The Baum-Welsh algorithm together with its derivatives and variations has been the main technique for learning Hidden Markov Models (HMM) from observational data. We present an HMM learning algorithm based on the non-negative matrix factorization (NMF) of higher order Markovian statistics that is structurally different from the Baum-Welsh and its associated approaches. The described algorithm supports estimation of the number of recurrent states of an HMM and iterates the non-negative matrix factorization (NMF) algorithm to improve the learned HMM parameters. Numerical examples are provided as well.
Replicating hedge fund returns: A factor model approach
Naser, Omar
2007-01-01
Growth in the Hedge Fund industry mirrors the growth in the Mutual Fund industry. This raises the possibility of creating a passive strategy that replicates Hedge Fund returns at lower cost using liquid, exchange-traded instruments. Using monthly returns for the period 1991-2005 on thirteen Hedge Fund strategies, I build a linear factor models (“clones”) that replicate Hedge Fund returns. I use six common factors to determine the amount of expected return and variation in returns that can be ...
QCD dipole model and $k_{T}$ factorization
Bialas, A; Peschanski, R
2001-01-01
It is shown that the colour dipole approach to hard scattering at high energy is fully compatible with k_T factorization at the leading logarithm approximation (in -log x_Bj). The relations between the dipole amplitudes and unintegrated diagonal and non-diagonal gluon distributions are given. It is also shown that including the exact gluon kinematics in the k_T factorization formula destroys the conservation of transverse position vectors and thus is incompatible with the dipole model for both elastic and diffractive amplitudes.
Which psychological factors influence Internet addiction? Evidence through an integrative model
Burnay, Jonathan; Billieux, Joël; Blairy, Sylvie; Laroi, Frank
2015-01-01
Since the appearance of Internet, several preoccupations have appeared as a result, with Internet addiction being one of the most common. The goals of the present study were two-fold. First, to examine which psychological factors are relevant to explain Internet addiction, including impulsivity, passion and social provision. Second, to incorporate all these factors into an integrative model. Based on multiple regressions and path analysis, results revealed a positive relation between Internet...
Directory of Open Access Journals (Sweden)
Lenka Kovářová
2012-09-01
Full Text Available BACKGROUND: The triathlon is a combination of three different types of sport – swimming, cycling, and running. Each of these requires different top level predispositions and complex approach to talent selection is a rather difficult process. Attempts to identify assumptions in the triathlon have so far been specific and focused only on some groups of predispositions (physiology, motor tests, and psychology. The latest studies missed the structural approach and were based on determinants of sport performance, theory of sports training and expert assessment. OBJECTIVE: The aim of our study was to verify the model of predisposition in the short triathlon for talent assessment of young male athletes age 17–20 years. METHODS: The research sample consisted of 55 top level triathletes – men, who were included in the Government supported sports talent programme in the Czech Republic at the age of 17–20 years. We used a confirmative factor analysis (FA and Path diagram to verify the model, which allow us to explain mutual relationships among observed variables. For statistical data processing we used a structure equating modeling (SEM by software Lisrel L88. RESULTS: The study confirms best structural model for talent selection in triathlon at the age of 17–20 years old men, which composed seventeen indicators (tests and explained 91% of all cross-correlations (Goodness of Fit Index /GFI/ 0.91, Root Mean Square Residual /RMSR/ 0.13. Tests for predispositions in triathlons were grouped into five items, three motor predispositions (swimming, cycling and running skills, aerobic and psychological predispositions. Aerobic predispositions showed the highest importance to the assumptions to the general factor (1.00; 0. Running predispositions were measured as a very significant factor (–0.85; 0.28 which confirms importance of this critical stage of the race. Lower factor weight showed clusters of swimming (–0.61; 0.63 and cycling (0.53; 0
Jang, Seon-Kyeong; Choi, Hye-Im; Park, Soohyun; Jaekal, Eunju; Lee, Ga-Young; Cho, Young Il; Choi, Kee-Hong
2016-01-01
Acknowledging separable factors underlying negative symptoms may lead to better understanding and treatment of negative symptoms in individuals with schizophrenia. The current study aimed to test whether the negative symptoms factor (NSF) of the Positive and Negative Syndrome Scale (PANSS) would be better represented by expressive and experiential deficit factors, rather than by a single factor model, using confirmatory factor analysis (CFA). Two hundred and twenty individuals with schizophrenia spectrum disorders completed the PANSS; subsamples additionally completed the Brief Negative Symptom Scale (BNSS) and the Motivation and Pleasure Scale-Self-Report (MAP-SR). CFA results indicated that the two-factor model fit the data better than the one-factor model; however, latent variables were closely correlated. The two-factor model's fit was significantly improved by accounting for correlated residuals between N2 (emotional withdrawal) and N6 (lack of spontaneity and flow of conversation), and between N4 (passive social withdrawal) and G16 (active social avoidance), possibly reflecting common method variance. The two NSF factors exhibited differential patterns of correlation with subdomains of the BNSS and MAP-SR. These results suggest that the PANSS NSF would be better represented by a two-factor model than by a single-factor one, and support the two-factor model's adequate criterion-related validity. Common method variance among several items may be a potential source of measurement error under a two-factor model of the PANSS NSF.
Mohamed, Mafauzy; Winn, Than; Rampal, Gr Lekhraj; Abdul Rashid, Ar; Mustaffa, Be
2005-01-01
Cardiovascular disease (CVD) has been the number one cause of death since the last three decades in Malaysia and diabetes mellitus and hypertension are considered as major risk factors. A study to reduce risk factors for cardiovascular diseases in the community (PIKOM) through education and lifestyle changes was undertaken. The study population was from four different areas in Peninsular Malaysia - Kota Bharu and Bachok in Kelantan ; Raub in Pahang; Gunung Besout in Perak and Felda Palong in Negri Sembilan. The subjects invited to participate in this study ware aged between 30 - 65 years, did not have any debilitating illnesses and no known history of diabetes mellitus, hypertension or cardiovascular disease. Subjects were asked to come to the local clinic in a fasting state and after physical examination, blood was taken for plasma glucose and lipids. Oral glucose tolerance test (OGTT) was then performed. A total of 4,121 subjects participated in the study. The proportion of subjects with diabetes mellitus was highest in Felda Palong area (20.3%) and lowest in Raub area (7.1%). The proportion of subjects with hypertension was also highest in Felda Palong area (38.6%) and lowest in Raub area (29.1%). This could be attributable to the subjects in Felda Palong having the highest mean Body Mass Index (BMI) and Waist-to-Hip Ratio (WHR). There were significant associations between diabetes and hypertension with age and obesity. Subjects with diabetes mellitus and hypertension also had the highest mean age, BMI, WHR and plasma cholesterol.In conclusion, the proportion of patients with risk factors for CVD was high and intervention studies through education and lifestyle changes were being carried out to see their effectiveness.
Supratentorial low-grade glioma: results and prognostic factors following postoperative radiotherapy
Energy Technology Data Exchange (ETDEWEB)
Grabenbauer, G.G.; Roedel, C.M.; Schuchardt, U.; Sauer, R. [Erlangen-Nuernberg Univ., Erlangen (Germany). Dept. of Radiation Oncology; Paulus, W. [Erlangen-Nuernberg Univ., Erlangen (Germany). Dept. of Neuropathology; Ganslandt, O.; Buchfelder, M.; Schrell, U.; Fahlbusch, R. [Erlangen-Nuernberg Univ., Erlangen (Germany). Neurochirurgische Klinik mit Poliklinik; Huk, W.J. [Erlangen-Nuernberg Univ., Erlangen (Germany). Dept. of Neuroradiology
2000-06-01
Background and Purpose: To assess treatment outcome and prognostic factors following postoperative external radiotherapy in 77 patients with low-grade glioma. Patients and Methods: Between 1977 and 1996, 45 patients with astrocytoma, 14 with oligodendroglioma and 18 with mixed glioma received postoperative radiotherapy with a median total dose of 52 Gy (range, 45 to 61 Gy). Sixty-seven patients were treated immediately following surgery, 10 patients with tumor progression. The influence of various factors including histology, gender, age, seizures, duration of symptoms ({<=}6 weeks vs >6 weeks), CT pattern (enhancement vs no enhancement), type of surgery, total radiotherapy dose and timing of radiotherapy on relapse-free survival and overall survival was investigated. Results: The median overall survival time was 81 months, the 5- and 10-year survival rates were 54% and 31%, respectively. The median time to progression was 56 months, while the 5- and 10-year progression-free survival rates were 45% and 24%. Univariate analyses identified the total radiotherapy dose (p=0.01), duration of symptoms (p=0.05), the presence of seizures (p=0.04), and the CT pattern following intravenous contrast (p=0.005) as significant prognostic factors for overall survival. Progression-free survival rates were influenced by the total dose (p=0.04), the duration of symptoms (p=0.01) and CT pattern (p=0.006). On multivariate analysis, only the CT pattern (enhancement vs no enhancement) remained as independent prognostic factors for both progession-free survival and overall survival. Conclusion: A minimum total dose of 52 Gy is recommended for the postoperative radiotherapy in low-grade glioma. Tumors with CT enhancement seem to need further intensification of treatment. (orig.) [German] Hintergrund: Es sollten Ergebnisse und Prognosefaktoren nach postoperativer Radiotherapie bei 77 Patienten mit Low-grade-Gliomen evaluiert werden. Patienten und Methoden: Zwischen 1977 und 1996 wurden 45
Soil and water assessment tool model calibration results for different catchment sizes in poland.
Ostojski, Mieczyslaw S; Niedbala, Jerzy; Orlinska-Wozniak, Paulina; Wilk, Pawel; Gębala, Joanna
2014-01-01
The watershed model SWAT (Soil and Water Assessment Tool) can be used to implement the requirements of international agreements that Poland has ratified. Among these requirements are the establishment of catchment-based, rather than administrative-based, management plans and spatial information systems. Furthermore, Polish law requires that management of water resources be based on catchment systems. This article explores the use of the SWAT model in the implementation of catchment-based water management in Poland. Specifically, the impacts of basin size on calibration and on the results of the simulation process were analyzed. SWAT was set up and calibrated for three Polish watersheds of varying sizes: (i) Gąsawka, a small basin (>593.7 km), (ii) Rega, a medium-sized basin (2766.8 km), and (iii) Warta, a large basin (54,500 km) representing about 17.4% of Polish territory. The results indicated that the size of the catchment has an impact on the calibration process and simulation outputs. Several factors influenced by the size of the catchment affected the modeling results. Among these factors are the number of measurement points within the basin and the length of the measuring period and data quality at checkpoints as determined by the position of the measuring station. It was concluded that the SWAT model is a suitable tool for the implementation of catchment-based water management in Poland regardless of watershed size. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
On the relation between the linear factor model and the latent profile model
Halpin, P.F.; Dolan, C.V.; Grasman, R.P.P.P.; de Boeck, P.
2011-01-01
The relationship between linear factor models and latent profile models is addressed within the context of maximum likelihood estimation based on the joint distribution of the manifest variables. Although the two models are well known to imply equivalent covariance decompositions, in general they do
On the Relation between the Linear Factor Model and the Latent Profile Model
Halpin, Peter F.; Dolan, Conor V.; Grasman, Raoul P. P. P.; De Boeck, Paul
2011-01-01
The relationship between linear factor models and latent profile models is addressed within the context of maximum likelihood estimation based on the joint distribution of the manifest variables. Although the two models are well known to imply equivalent covariance decompositions, in general they do not yield equivalent estimates of the…
National Research Council Canada - National Science Library
PATERNITI, S; NIEDHAMMER, I; LANG, T; CONSOLI, S. M
2002-01-01
.... This association could be explained by personality traits. To examine the relationship between psychosocial factors at work and changes in depressive symptoms, taking into account personality traits...
Error statistics of hidden Markov model and hidden Boltzmann model results
Directory of Open Access Journals (Sweden)
Newberg Lee A
2009-07-01
Full Text Available Abstract Background Hidden Markov models and hidden Boltzmann models are employed in computational biology and a variety of other scientific fields for a variety of analyses of sequential data. Whether the associated algorithms are used to compute an actual probability or, more generally, an odds ratio or some other score, a frequent requirement is that the error statistics of a given score be known. What is the chance that random data would achieve that score or better? What is the chance that a real signal would achieve a given score threshold? Results Here we present a novel general approach to estimating these false positive and true positive rates that is significantly more efficient than are existing general approaches. We validate the technique via an implementation within the HMMER 3.0 package, which scans DNA or protein sequence databases for patterns of interest, using a profile-HMM. Conclusion The new approach is faster than general naïve sampling approaches, and more general than other current approaches. It provides an efficient mechanism by which to estimate error statistics for hidden Markov model and hidden Boltzmann model results.
Error statistics of hidden Markov model and hidden Boltzmann model results
Newberg, Lee A
2009-01-01
Background Hidden Markov models and hidden Boltzmann models are employed in computational biology and a variety of other scientific fields for a variety of analyses of sequential data. Whether the associated algorithms are used to compute an actual probability or, more generally, an odds ratio or some other score, a frequent requirement is that the error statistics of a given score be known. What is the chance that random data would achieve that score or better? What is the chance that a real signal would achieve a given score threshold? Results Here we present a novel general approach to estimating these false positive and true positive rates that is significantly more efficient than are existing general approaches. We validate the technique via an implementation within the HMMER 3.0 package, which scans DNA or protein sequence databases for patterns of interest, using a profile-HMM. Conclusion The new approach is faster than general naïve sampling approaches, and more general than other current approaches. It provides an efficient mechanism by which to estimate error statistics for hidden Markov model and hidden Boltzmann model results. PMID:19589158
Sato, N.; Sellers, P. J.; Randall, D. A.; Schneider, E. K.; Shukla, J.; Kinter, J. L., III; Hou, Y.-T.; Albertazzi, E.
1989-01-01
The Simple Biosphere MOdel (SiB) of Sellers et al., (1986) was designed to simulate the interactions between the Earth's land surface and the atmosphere by treating the vegetation explicitly and relistically, thereby incorporating biophysical controls on the exchanges of radiation, momentum, sensible and latent heat between the two systems. The steps taken to implement SiB in a modified version of the National Meteorological Center's spectral GCM are described. The coupled model (SiB-GCM) was used with a conventional hydrological model (Ctl-GCM) to produce summer and winter simulations. The same GCM was used with a conventional hydrological model (Ctl-GCM) to produce comparable 'control' summer and winter variations. It was found that SiB-GCM produced a more realistic partitioning of energy at the land surface than Ctl-GCM. Generally, SiB-GCM produced more sensible heat flux and less latent heat flux over vegetated land than did Ctl-GCM and this resulted in the development of a much deeper daytime planetary boundary and reduced precipitation rates over the continents in SiB-GCM. In the summer simulation, the 200 mb jet stream and the wind speed at 850 mb were slightly weakened in the SiB-GCM relative to the Ctl-GCM results and equivalent analyses from observations.
Institute of Scientific and Technical Information of China (English)
WU Hao; CHEN Xiaoling; HE Ying; HE Xiaorong; CAI Xiaobin; XU Keyan
2006-01-01
Indicator systems of environmental sustainable development in the Poyang Lake Basin are established from 51 elementary indexes by factor analysis, which is composed of four steps such as the factor model, the parameter estimation, the factor rotation and the factor score. Under the condition that the cumulative proportion is greater than 85%, 5 explicit factors of environmental sustainable development as well as its factor score by region are carried out. The result indicates some impact factors to the basin environmental in descending sort order are volume of water, volume of waste gas discharge, volume of solid wastes, the degree to comprehensive utilization of waste gas, waste water and solid wastes, the emission volume of waste gas, waste water and solid wastes. It is helpful and important to provide decision support for constituting sustainable development strategies and evaluate the sustainable development status of each city.
Menache, D; Behre, H E; Orthner, C L; Nunez, H; Anderson, H D; Triantaphyllopoulos, D C; Kosow, D P
1984-12-01
Thrombosis and/or disseminated intravascular coagulation (DIC) are complications specifically associated with the use of factor IX complex in some patients. Assuming that these complications might result from zymogen overload, we have produced, using diethylaminoethyl (DEAE)-Sephadex (Pharmacia, Piscataway, NJ) and sulfated dextran chromatography, a factor IX concentrate (coagulation factor IX) that is essentially free of prothrombin, factor VII, and factor X. Factor IX specific activity is at least 5 U/mg protein, a 250-fold purification compared to plasma. Amounts of factors II, VII, and X are less than 5 units each per 100 units of factor IX. The concentrate is essentially free of activated clotting factors and contains no added heparin. In the rabbit stasis model, a dose of 200 factor IX U/kg was less thrombogenic than 100 factor IX U/kg of the DEAE-Sephadex eluate from which the concentrate was derived. Infusion of 200 factor IX U/kg did not induce DIC in the nonstasis rabbit model, whereas 100 factor IX U/kg of the DEAE-Sephadex eluate resulted in DIC in this model. Several factor IX lots were found to have shortened nonactivated partial thromboplastin times (PTTs), but were nonthrombogenic in both animal models. These data indicate that coagulation factor IX concentrate is less thrombogenic than factor IX complex.
Factors Impacting Habitable Volume Requirements: Results from the 2011 Habitable Volume Workshop
Simon, M.; Whitmire, A.; Otto, C.; Neubek, D. (Editor)
2011-01-01
This report documents the results of the Habitable Volume Workshop held April 18-21, 2011 in Houston, TX at the Center for Advanced Space Studies-Universities Space Research Association. The workshop was convened by NASA to examine the factors that feed into understanding minimum habitable volume requirements for long duration space missions. While there have been confinement studies and analogs that have provided the basis for the guidance found in current habitability standards, determining the adequacy of the volume for future long duration exploration missions is a more complicated endeavor. It was determined that an improved understanding of the relationship between behavioral and psychosocial stressors, available habitable and net habitable volume, and interior layouts was needed to judge the adequacy of long duration habitat designs. The workshop brought together a multi-disciplinary group of experts from the medical and behavioral sciences, spaceflight, human habitability disciplines and design professionals. These subject matter experts identified the most salient design-related stressors anticipated for a long duration exploration mission. The selected stressors were based on scientific evidence, as well as personal experiences from spaceflight and analogs. They were organized into eight major categories: allocation of space; workspace; general and individual control of environment; sensory deprivation; social monotony; crew composition; physical and medical issues; and contingency readiness. Mitigation strategies for the identified stressors and their subsequent impact to habitat design were identified. Recommendations for future research to address the stressors and mitigating design impacts are presented.
Directory of Open Access Journals (Sweden)
Deborah T. Gold
2011-01-01
Full Text Available Purpose. Determine patient-reported reasons for discontinuation with teriparatide. Methods. Patients taking teriparatide in a multicenter, prospective, and observational study were given three questionnaires: baseline, follow-up questionnaire 1 (QF1, 2 to 6 months, and follow-up questionnaire 2 (QF2, 12 months. Discontinuation reported at QF1 and QF2 was defined as “early” and “late,” respectively, and remaining patients were considered persistent. Cochran-Armitage trend test was used to identify factors associated with discontinuation. Results. Side effects, concern about improper use, injection difficulties, and several patient-perceived physician issues were associated with early discontinuation. Low patient-perceived importance of continuing treatment, side effects, difficulty paying, and low patient-perceived physician knowledge were associated with late discontinuation. The most common specific reasons selected for discontinuing treatment were “concerns about treatment outweighing the benefits” (n=53 and “difficulty paying” (n=47. Conclusions. Persistence with teriparatide is dependent on managing side effects, addressing financial challenges, proper training, and obtaining support from the healthcare provider.
Kirschner, Wolf; Dudenhausen, Joachim W; Henrich, Wolfgang
2016-04-01
The conditions of iron deficiency are highly incident in pregnancy with elevated risks for preterm birth and low birth weight. In our recent study, we found 6% of participants having anemia, whereas between 39% and 47% showed iron deficiency without anemia. In many countries in prenatal care solely hemoglobin (Hb) measurement is applied. For the gynecologists till date there is no indication to determine other markers (e.g., serum-ferritin). As iron deficiency results from an imbalance between intake and loss of iron, our aim was to find out if the risk of iron deficiency conditions can be estimated by a diet history protocol as well as questionnaires to find about iron loss. We found that the risk of having iron deficiency in upper gestational week (>=21) increased by a factor of five. Thus, additional diagnostics should be done in this group by now. Using the questionnaire as a screening instrument, we further estimated the probability of disease in terms of a positive likelihood ratio (LR+). The positive LR for the group below 21th week of gestation is 1.9 thus, increasing the post-test probability to 52% from 36% as before. Further research based on higher sample sizes will show if the ratios can be increased further.
Proposition Factor Model of World Class Manufacturing in Brazilian Enterprises
Directory of Open Access Journals (Sweden)
Paulo Sergio Gonçalves de Oliveira
2016-05-01
Full Text Available The present paper aims to develop a model of World Class Manufacturing, to achieve this goal was elaborated a questionnaire with 35 assertive divided in 7 areas suggested by literature review. This questionnaire was send to manufacture specialists, product developers and technician through LinkedIn the participants was select by researchers in discussion groups taking in consideration their experience using the professional profile. About 1000 invite was send to professional from metal-mechanic sector which returned 180 valid questionnaires. The data was analyzed through factor analyses and was obtained 7 constructs, which explained 67% of data variance. The KMO was 0,84, which is considered good for, analyzes purpose. The seventh factor was eliminated because it Cranach’s Alpha was below 0,6 and the remained factor was nominated as: Lean Manufacturing, Human Resources Management to achieve flexibility, Marketing Integration, Costs Reduction and Flexibility.
MacCann, Carolyn; Joseph, Dana L; Newman, Daniel A; Roberts, Richard D
2014-04-01
This article examines the status of emotional intelligence (EI) within the structure of human cognitive abilities. To evaluate whether EI is a 2nd-stratum factor of intelligence, data were fit to a series of structural models involving 3 indicators each for fluid intelligence, crystallized intelligence, quantitative reasoning, visual processing, and broad retrieval ability, as well as 2 indicators each for emotion perception, emotion understanding, and emotion management. Unidimensional, multidimensional, hierarchical, and bifactor solutions were estimated in a sample of 688 college and community college students. Results suggest adequate fit for 2 models: (a) an oblique 8-factor model (with 5 traditional cognitive ability factors and 3 EI factors) and (b) a hierarchical solution (with cognitive g at the highest level and EI representing a 2nd-stratum factor that loads onto g at λ = .80). The acceptable relative fit of the hierarchical model confirms the notion that EI is a group factor of cognitive ability, marking the expression of intelligence in the emotion domain. The discussion proposes a possible expansion of Cattell-Horn-Carroll theory to include EI as a 2nd-stratum factor of similar standing to factors such as fluid intelligence and visual processing.
Adjuvant radiotherapy in stage 1 seminoma: Evaluation of prognostic factors and results of survival.
Serdar, Lasif; Canyilmaz, Emine; Topcu, Turkan Ozturk; Sahbaz, Asli; Memis, Yahyahan; Soydemir, Gulsen; Aynaci, Ozlem; Kandaz, Mustafa; Bahat, Zümrüt; Yoney, Adnan
2015-01-01
The purpose of this study was to evaluate the prognostic factors affecting overall survival (OS), cause-specific survival (CSS), progression-free survival (PFS), and survival among patients undergoing adjuvant radiotherapy (RT) for stage-1 seminoma. Between August 1997 and May 2013, 68 patients diagnosed with stage-1 seminoma were retrospectively evaluated. The median age was 39 (24-74) years. All patients received adjuvant RT after inguinal orchiectomy. Fifty-eight (85.3%) patients received paraaortic RT; 10 (14.7%) received dog-leg field RT. The median RT dose was 23.4 (23.4-30.6) Gy. The median follow-up period was 77.5 (6.7-198.5) months. During the follow-up period, two patients developed distant metastasis, and none developed local recurrence. Two patients died from seminoma, and three died for other reasons. The 5, 10, and 15-year OS rates were 94.7%, 89.6%, and 89.6%, respectively. The 5, 10, and 15-year CSS rates were 98.5%, 96%, and 96%, respectively. The 5, 10, and 15-year PFS rate was 96.1%. The univariate analysis showed that only histological subtype was significant for OS. The 10-year survival rate was 100% among patients with seminoma histology, 90.8% among patients with a classic seminoma histology, and 50% among patients with an anaplastic seminoma histology (P seminoma was a negative prognostic indicator for OS (P = 0.042). Adjuvant RT resulted in excellent long-term survival and local control in patients with stage-1 seminoma after orchiectomy. During a short follow-up, secondary malignancy (SM) and late cardiovascular morbidity were not observed. Despite those results, concern of SM and late cardiovascular morbidity remains.
Octet baryon electromagnetic form factors in a relativistic quark model
Ramalho, G
2011-01-01
We study the octet baryon electromagnetic properties by applying the covariant spectator quark model, and provide covariant parametrization that can be used to study baryon electromagnetic reactions. While we use the lattice QCD data in the large pion mass regime (small pion cloud effects) to determine the parameters of the model in the valence quark sector, we use the nucleon physical and octet baryon magnetic moment data to parameterize the pion cloud contributions. The valence quark contributions for the octet baryon electromagnetic form factors are estimated by extrapolating the lattice parametrization in the large pion mass regime to the physical regime. As for the pion cloud contributions, we parameterize them in a covariant, phenomenological manner, combined with SU(3) symmetry. We also discuss the impact of the pion cloud effects on the octet baryon electromagnetic form factors and their radii.
Octet Baryon Electromagnetic Form Factors in a Relativistic Quark Model
Energy Technology Data Exchange (ETDEWEB)
Gilberto Ramalho, Kazuo Tsushima
2011-09-01
We study the octet baryon electromagnetic properties by applying the covariant spectator quark model, and provide covariant parametrization that can be used to study baryon electromagnetic reactions. While we use the lattice QCD data in the large pion mass regime (small pion cloud effects) to determine the parameters of the model in the valence quark sector, we use the nucleon physical and octet baryon magnetic moment data to parameterize the pion cloud contributions. The valence quark contributions for the octet baryon electromagnetic form factors are estimated by extrapolating the lattice parametrization in the large pion mass regime to the physical regime. As for the pion cloud contributions, we parameterize them in a covariant, phenomenological manner, combined with SU(3) symmetry. We also discuss the impact of the pion cloud effects on the octet baryon electromagnetic form factors and their radii.
Cane, M. A.
1979-01-01
A time-dependent, primitive equation, beta plane model that is two-dimensional in the horizontal has been developed to model wind-driven equatorial ocean circulation. A simple vertical structure consisting of two layers above the thermocline with the same constant density permits a steady-state undercurrent in the model. An analytical study of the linear dynamics of the model suggests that the addition of inertial effects is needed to simulate the undercurrent properly. Also, both linear and nonlinear dynamics of the model are investigated numerically. Such nonlinear response to wind stress as a strong eastward equatorial undercurrent and an intense eastward 'countercurrent' at three deg N are noted in the numerical results.
The pion electromagnetic form-factor in a QCD-inspired model
Pacheco-Bicudo-Cabral de Melo, J; Pace, E; Salmè, G
2004-01-01
We present detailed numerical results for the pion space-like electromagnetic form factor obtained within a recently proposed model of the pion electromagnetic current in a confining light-front QCD-inspired model. The model incorporates the vector meson dominance mechanism at the quark level, where the dressed photon with $q^+>0$ decay in an interacting quark-antiquark pair,wich absorbs the initial pion and produces the pion in the final state.
Neuroprotective Transcription Factors in Animal Models of Parkinson Disease
François-Xavier Blaudin de Thé; Hocine Rekaik; Alain Prochiantz; Julia Fuchs; Joshi, Rajiv L.
2015-01-01
A number of transcription factors, including En1/2, Foxa1/2, Lmx1a/b, Nurr1, Otx2, and Pitx3, with key roles in midbrain dopaminergic (mDA) neuron development, also regulate adult mDA neuron survival and physiology. Mouse models with targeted disruption of some of these genes display several features reminiscent of Parkinson disease (PD), in particular the selective and progressive loss of mDA neurons in the substantia nigra pars compacta (SNpc). The characterization of these animal models ha...
Factor models on locally tree-like graphs
Dembo, Amir; Sun, Nike
2011-01-01
We consider homogeneous factor models on uniformly sparse graph sequences converging locally to a (unimodular) random tree T, and study the existence of the free energy density phi, the limit of the log-partition function divided by the number of vertices n as n tends to infinity. We provide a new interpolation scheme and use it to prove existence of, and to explicitly compute, the quantity phi subject to uniqueness of a relevant Gibbs measure for the factor model on T. By way of example we compute phi for the independent set (or hard-core) model at low fugacity, for the ferromagnetic Ising model at all parameter values, and for the ferromagnetic Potts model with both weak enough and strong enough interactions. Even beyond uniqueness our interpolation provides useful explicit bounds on phi. In the regimes in which we establish existence of the limit, we show that it coincides with the Bethe free energy functional evaluated at a suitable fixed point of the belief propagation recursions on T. In the special cas...
Modeling impact of environmental factors on photovoltaic array performance
Energy Technology Data Exchange (ETDEWEB)
Yang, Jie; Sun, Yize; Xu, Yang [College of Mechanical Engineering, Donghua University NO.2999, North Renmin Road, Shanghai (China)
2013-07-01
It is represented in this paper that a methodology to model and quantify the impact of the three environmental factors, the ambient temperature, the incident irradiance and the wind speed, upon the performance of photovoltaic array operating under outdoor conditions. First, A simple correlation correlating operating temperature with the three environmental variables is validated for a range of wind speed studied, 2-8, and for irradiance values between 200 and 1000. Root mean square error (RMSE) between modeled operating temperature and measured values is 1.19% and the mean bias error (MBE) is -0.09%. The environmental factors studied influence I-V curves, P-V curves, and maximum-power outputs of photovoltaic array. The cell-to-module-to-array mathematical model for photovoltaic panels is established in this paper and the method defined as segmented iteration is adopted to solve the I-V curve expression to relate model I-V curves. The model I-V curves and P-V curves are concluded to coincide well with measured data points. The RMSE between numerically calculated maximum-power outputs and experimentally measured ones is 0.2307%, while the MBE is 0.0183%. In addition, a multivariable non-linear regression equation is proposed to eliminate the difference between numerically calculated values and measured ones of maximum power outputs over the range of high ambient temperature and irradiance at noon and in the early afternoon. In conclusion, the proposed method is reasonably simple and accurate.
Models of Labour Services and Estimates of Total Factor Productivity
Robert Dixon; David Shepherd
2007-01-01
This paper examines the manner in which labour services are modelled in the aggregate production function, concentrating on the relationship between numbers employed and average hours worked. It argues that numbers employed and hours worked are not perfect substitutes and that conventional estimates of total factor productivity which, by using total hours worked as the measure of labour services, assume they are perfect substitutes, will be biased when there are marked changes in average hour...
Bühler, Joël; Keller, Ferdinand; Läge, Damian
2014-09-01
An adequate assessment of depression has been of concern to many researchers over the last half-century. These efforts have brought forth a manifold of depression rating scales, of which the Beck Depression Inventory (BDI) is 1 of the most commonly used self-assessment scales. Since its revision, the item structure of the BDI-II has been examined in many factor analytic studies, yet it has not been possible to achieve a consensus about the underlying factor structure. Recent findings from a nonmetric multidimensional scaling (NMDS) analysis (Bühler, Keller, & Läge, 2012) of the German norming sample of the BDI-II emphasized a structure with different qualitative aspects of depression, which suggested that the existing factor models do not adequately represent the data. The NMDS results were reviewed, and on the basis of these findings, a different factor model is proposed. In contrast to the common factor models in the literature, the presented model includes an additional factor, which is associated with the activation level of the BDI-II symptoms. The model was evaluated with a 2nd sample of patients diagnosed with a primary affective disorder (N = 569) and obtained good fit indices that even exceeded the fit of the most reliable factor model (Ward, 2006) described in the literature so far. Furthermore, emphasis is placed on the methodological question of how factor models may be derived from the results of NMDS analyses. PsycINFO Database Record (c) 2014 APA, all rights reserved.
Directory of Open Access Journals (Sweden)
Teslova OA
2012-02-01
Full Text Available Oxana A Teslova1,2, Takehiko Hiroma1, Elena I Baranovskaya2, Tomohiko Nakamura11Division of Neonatology, Nagano Children's Hospital, Azumino City, Nagano, Japan; 2Department of Obstetrics and Gynecology, Gomel State Medical University, BelarusBackground: The stable microbubble test (SMT is a sensitive and specific means of predicting respiratory distress syndrome in newborns, using quantitative correlations with concentrations of the protein and lipid components of surfactant. We hypothesized that fetal nutrition would affect the synthesis of surfactant components. The objectives of this study were to evaluate aspects of fetal and maternal nutrition influencing SMT results and related to development of respiratory distress syndrome in preterm neonates.Methods: Data from 194 preterm neonates of gestational age 23–36 weeks were analyzed using multivariate regression modeling to identify factors influencing SMT results. After adjusting for gestational age, we compared obstetric, maternal, neonatal, and placental data using analysis of variance in 99 neonates at 30–33 weeks of gestation based on results of the SMT. Receiver-operating-characteristic analysis was performed to characterize factors predictive of respiratory distress syndrome.Results: SMT results were most strongly associated with the concentration of protein in neonatal blood (P < 0.05 and maternal weight gain during pregnancy (P < 0.05. Cutoff values for predicting respiratory distress syndrome were serum protein <4.7 g/L and maternal weight gain <200 g/week.Conclusion: Inadequate maternal weight gain during pregnancy may play a significant role in immaturity of the surfactant system in the lungs and may be a predictor of respiratory distress syndrome in premature babies.Keywords: stable microbubble test, respiratory distress syndrome, protein concentration, gestational weight gain
PWSCC Growth Assessment Model Considering Stress Triaxiality Factor for Primary Alloy 600 Components
Directory of Open Access Journals (Sweden)
Jong-Sung Kim
2016-08-01
Full Text Available We propose a primary water stress corrosion cracking (PWSCC initiation model of Alloy 600 that considers the stress triaxiality factor to apply to finite element analysis. We investigated the correlation between stress triaxiality effects and PWSCC growth behavior in cold-worked Alloy 600 stream generator tubes, and identified an additional stress triaxiality factor that can be added to Garud's PWSCC initiation model. By applying the proposed PWSCC initiation model considering the stress triaxiality factor, PWSCC growth simulations based on the macroscopic phenomenological damage mechanics approach were carried out on the PWSCC growth tests of various cold-worked Alloy 600 steam generator tubes and compact tension specimens. As a result, PWSCC growth behavior results from the finite element prediction are in good agreement with the experimental results.
PWSCC growth assessment model considering stress triaxiality factor for primary alloy 600 components
Energy Technology Data Exchange (ETDEWEB)
Kim, Jong Sung [Dept. of Nuclear Engineering, Sejong University, Seoul (Korea, Republic of); Kim, Ji Soo; Jeon, Jun Young; Kim, Yun Jae [Dept. of of Mechanical Engineering, Korea University, Seoul (Korea, Republic of)
2016-08-15
We propose a primary water stress corrosion cracking (PWSCC) initiation model of Alloy 600 that considers the stress triaxiality factor to apply to finite element analysis. We investigated the correlation between stress triaxiality effects and PWSCC growth behavior in cold-worked Alloy 600 stream generator tubes, and identified an additional stress triaxiality factor that can be added to Garud's PWSCC initiation model. By applying the proposed PWSCC initiation model considering the stress triaxiality factor, PWSCC growth simulations based on the macroscopic phenomenological damage mechanics approach were carried out on the PWSCC growth tests of various cold-worked Alloy 600 steam generator tubes and compact tension specimens. As a result, PWSCC growth behavior results from the finite element prediction are in good agreement with the experimental results.
Studying Term Structure of SHIBOR with the Two-Factor Vasicek Model
Directory of Open Access Journals (Sweden)
Chaoqun Ma
2014-01-01
Full Text Available With the development of the Chinese interest rate market, SHIBOR is playing an increasingly important role. Based on principal component analysing SHIBOR, a two-factor Vasicek model is established to portray the change in SHIBOR with different terms. And parameters are estimated by using the Kalman filter. The model is also used to fit and forecast SHIBOR with different terms. The results show that two-factor Vasicek model fits SHIBOR well, especially for SHIBOR in terms of three months or more.
CSIR Research Space (South Africa)
Das, Sonali
2010-01-01
Full Text Available This paper uses the dynamic factor model framework, which accommodates a large cross-section of macroeconomic time series, for forecasting regional house price inflation. In this study, the authors forecast house price inflation for five...
National Research Council Canada - National Science Library
Muthen, Bengt; Asparouhov, Tihomir; Rebollo, Irene
2006-01-01
This article discusses new latent variable techniques developed by the authors. As an illustration, a new factor mixture model is applied to the monozygotic-dizygotic twin analysis of binary items measuring alcohol-use disorder...
Assessment of scaling factor in modified dendrite growth model
Institute of Scientific and Technical Information of China (English)
张瑞丰; 沈宁福; 曹文博
2002-01-01
A model for dendrite growth during rapid solidification was established on the basis of BCT model and marginal stability criterion through modified Peclet numbers. Taking into account the interaction of diffusion fields, including solute diffusion field and thermal diffusion field around the dendrite tip, the model obtain a satisfactory results to predict the dendrite velocity and the tip radius, which agrees well with the experimental data from references in Cu-Ni alloy.
Higher plant modelling for life support applications: first results of a simple mechanistic model
Hezard, Pauline; Dussap, Claude-Gilles; Sasidharan L, Swathy
2012-07-01
In the case of closed ecological life support systems, the air and water regeneration and food production are performed using microorganisms and higher plants. Wheat, rice, soybean, lettuce, tomato or other types of eatable annual plants produce fresh food while recycling CO2 into breathable oxygen. Additionally, they evaporate a large quantity of water, which can be condensed and used as potable water. This shows that recycling functions of air revitalization and food production are completely linked. Consequently, the control of a growth chamber for higher plant production has to be performed with efficient mechanistic models, in order to ensure a realistic prediction of plant behaviour, water and gas recycling whatever the environmental conditions. Purely mechanistic models of plant production in controlled environments are not available yet. This is the reason why new models must be developed and validated. This work concerns the design and test of a simplified version of a mathematical model coupling plant architecture and mass balance purposes in order to compare its results with available data of lettuce grown in closed and controlled chambers. The carbon exchange rate, water absorption and evaporation rate, biomass fresh weight as well as leaf surface are modelled and compared with available data. The model consists of four modules. The first one evaluates plant architecture, like total leaf surface, leaf area index and stem length data. The second one calculates the rate of matter and energy exchange depending on architectural and environmental data: light absorption in the canopy, CO2 uptake or release, water uptake and evapotranspiration. The third module evaluates which of the previous rates is limiting overall biomass growth; and the last one calculates biomass growth rate depending on matter exchange rates, using a global stoichiometric equation. All these rates are a set of differential equations, which are integrated with time in order to provide
Institute of Scientific and Technical Information of China (English)
Bin-Bin Wang; Cai-Gang Liu; Ping Lu; A Latengbaolide; Yang Lu
2011-01-01
AIM: To investigate the efficiency of Cox proportional hazard model in detecting prognostic factors for gastric cancer.METHODS: We used the log-normal regression model to evaluate prognostic factors in gastric cancer and compared it with the Cox model. Three thousand and eighteen gastric cancer patients who received a gastrectomy between 1980 and 2004 were retrospectively evaluated. Clinic-pathological factors were included in a log-normal model as well as Cox model. The akaike information criterion (AIC) was employed to compare the efficiency of both models. Univariate analysis indicated that age at diagnosis, past history, cancer location, distant metastasis status, surgical curative degree, combined other organ resection, Borrmann type, Lauren's classification, pT stage, total dissected nodes and pN stage were prognostic factors in both log-normal and Cox models.RESULTS: In the final multivariate model, age at diagnosis,past history, surgical curative degree, Borrmann type, Lauren's classification, pT stage, and pN stage were significant prognostic factors in both log-normal and Cox models. However, cancer location, distant metastasis status, and histology types were found to be significant prognostic factors in log-normal results alone.According to AIC, the log-normal model performed better than the Cox proportional hazard model (AIC value:2534.72 vs 1693.56).CONCLUSION: It is suggested that the log-normal regression model can be a useful statistical model to evaluate prognostic factors instead of the Cox proportional hazard model.
Wang, Li; Zhang, Jianxin; Shi, Zhanbiao; Zhou, Mingjie; Li, Zhongquan; Zhang, Kan; Liu, Zhengkui; Elhai, Jon D
2011-08-01
The present study investigated the factor structure of posttraumatic stress disorder (PTSD) symptoms measured by the PTSD Checklist (PCL) in two large samples exposed to different traumatic events (an earthquake and a violent riot) from China. Despite the samples' difference in type of trauma, demographics, symptom severity, and elapsed time since trauma exposure, the results of a series of confirmatory factor analyses indicate that a five-factor intercorrelated model (intrusion, avoidance, numbing, dysphoric arousal, and anxious arousal) fit the data significantly better than the other alternative models including: the three-factor DSM-IV model, the four-factor numbing model (King et al., 1998), and the four-factor dysphoria model (Simms et al., 2002) in both samples. Implications and limitations regarding the results are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.
Late preterm infants – impact of perinatal factors on neonatal results. A clinical study
Directory of Open Access Journals (Sweden)
Grzegorz Jakiel
2015-09-01
Full Text Available Introduction. Infants born between the 34[sup]th[/sup] – 36[sup]th[/sup] week of pregnancy account for 75% of all preterm infants. Their seemingly slight immaturity is related to serious health problems. Objective. The aim of the study was to analyse perinatal factors that influence the occurrence in infants of such problems as respiratory failure, metabolic problems and early onset sepsis (EOS. Materials and method. The material for the study included all mothers and their late preterm infants: 34+0 – 36+6 born in our hospital (a tertiary referral academic centre in 2010 and 2011. The course of pregnancy and delivery, the type of delivery, applied preventive measures and treatment, as well as demographic data and the clinical state of infants were all analysed. Data from individual documentation of each mother and infant were collected by 5 designated people and data reliability was independently monitored by a random control of the documentation conducted by the supervising person. Results. A statistically significant relationship between the occurrence of respiratory distress syndrome and infant immaturity, bad state after birth and sepsis in infants were confirmed. Sepsis was more common in the case of vaginal delivery, and coexisted with respiratory distress syndrome. The mother’s diseases during pregnancy, a perinatal preventive antibiotic therapy, and possible delivery complications did not influence the infection. Perinatal asphyxia in an infant positively correlated with a Caesarean section and respiratory distress syndrome after birth. Conclusions. It is necessary to thoroughly establish the type of delivery of a late preterm infant in order to prevent an infection in the newborn child. The improvement of diagnosis of intrauterine hypoxia may reduce the number of Caesarean sections. The decision about late preterm delivery should be based on indices of the mother’s state of health. Premature delivery is related to the